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+The Project Gutenberg eBook, Micrographia, by Robert Hooke
+
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+
+
+
+Title: Micrographia
+       Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries Thereupon
+
+
+Author: Robert Hooke
+
+Release Date: March 29, 2005  [eBook #15491]
+
+Language: English
+
+Character set encoding: ISO-646-US (US-ASCII)
+
+
+***START OF THE PROJECT GUTENBERG EBOOK MICROGRAPHIA***
+
+
+E-text prepared by Robert Shimmin, Keith Edkins, and the Project Gutenberg
+Online Distributed Proofreading Team
+
+
+
+Note: Project Gutenberg also has an HTML version of this
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+
+      The reader of this text file should understand that words or
+      phrases between underscores should be imagined to be set in italics.
+
+
+
+
+
+       *       *       *       *       *
+
+By the Council of the ROYAL SOCIETY of London
+for Improving of Natural Knowledge.
+
+Ordered, That the Book written by Robert Hooke, M.A. Fellow of this
+Society, Entituled, Micrographia, or some Physiological Descriptions of
+Minute Bodies, made by Magnifying Glasses, with Observations and Inquiries
+thereupon, Be printed by John Martyn, and James Allestry, Printers to
+the said Society.
+
+Novem. 23. 1664.
+
+BROUNCKER. P.R.S.
+
+       *       *       *       *       *
+
+
+MICROGRAPHIA:
+
+OR SOME
+
+Physiological Descriptions
+
+OF
+
+MINUTE BODIES
+
+MADE BY
+
+MAGNIFYING GLASSES
+
+WITH
+
+OBSERVATIONS and INQUIRIES thereupon.
+
+       *       *       *       *       *
+
+By R. HOOKE, Fellow of the ROYAL SOCIETY.
+
+       *       *       *       *       *
+
+
+
+
+
+
+  _Non possis oculo quantum contendere Linceus,
+  Non tamen idcirco contemnas Lippus inungi._ Horat. Ep. lib. 1.
+
+
+
+[Illustration]
+
+       *       *       *       *       *
+
+
+LONDON, Printed by Jo. Martyn, and Ja. Allestry, Printers to the
+ROYAL SOCIETY, and are to be sold at their Shop at the Bell in S.
+Paul's Church-yard. M DC LX V.
+
+       *       *       *       *       *
+
+
+TO THE
+
+KING.
+
+SIR,
+
+I Do here most humbly lay this _small_ Present at _Your Majesties_ Royal
+feet. And though it comes accompany'd with two _disadvantages_, the
+_meanness_ of the _Author_, and of the _Subject_; yet in both I am
+_incouraged_ by the _greatness_ of your _Mercy_ and your _Knowledge_. By
+the _one_ I am taught, that you can _forgive_ the most _presumptuous
+Offendors_: And by the _other_, that you will not _esteem_ the least work
+of _Nature_, or _Art_, unworthy your _Observation_. Amidst the many
+_felicities_ that have accompani'd _your Majesties_ happy _Restauration_
+and _Government_, it is none of the least considerable that _Philosophy_
+and _Experimental Learning_ have _prosper'd_ under your _Royal Patronage_.
+And as the calm prosperity of your Reign has given us the _leisure_ to
+follow these _Studies_ of _quiet_ and _retirement_, so it is just, that the
+_Fruits_ of them should, by way of _acknowledgement_, be return'd to _your
+Majesty_. There are, Sir, several other of your Subjects, of your _Royal
+Society_, now busie about _Nobler_ matters: The _Improvement_ of
+_Manufactures_ and _Agriculture_, the _Increase_ of _Commerce_, the
+_Advantage_ of _Navigation_: In all which they are _assisted_ by _your
+Majesties Incouragement_ and _Example_. Amidst all those _greater_ Designs,
+I here presume to bring in that which is more _proportionable_ to the
+_smalness_ of my Abilities, and to offer some of the _least_ of all
+_visible things_, to that _Mighty King_, that has _establisht an Empire_
+over the best of all _Invisible things_ of this World, the _Minds_ of Men.
+
+Your Majesties most humble
+and most obedient
+Subject and Servant,
+
+ROBERT HOOKE.
+
+       *       *       *       *       *
+
+TO THE
+
+ROYAL SOCIETY.
+
+After my _Address_ to our _Great Founder_ and _Patron_, I could not but
+think my self oblig'd, in consideration of those _many Ingagements_ you
+have laid upon me, to offer these my _poor Labours_ to this MOST
+ILLUSTRIOUS ASSEMBLY. YOU have been pleas'd formerly to accept of these
+rude _Draughts_. I have since added to them some _Descriptions_, and some
+_Conjectures_ of my own. And therefore, together with YOUR _Acceptance_, I
+must also beg YOUR _pardon_. The Rules YOU have prescrib'd YOUR selves in
+YOUR Philosophical Progress do seem the best that have ever yet been
+practis'd. And particularly that of avoiding _Dogmatizing_, and the
+_espousal_ of any _Hypothesis_ not sufficiently grounded and confirm'd by
+_Experiments_. This way seems the most excellent, and may preserve both
+_Philosophy_ and _Natural History_ from its former _Corruptions_. In saying
+which, I may seem to condemn my own Course in this Treatise; in which there
+may perhaps be some _Expressions_, which may seem more _positive_ then YOUR
+Prescriptions will permit: And though I desire to have them understood only
+as _Conjectures_ and _Quaeries_ (which YOUR Method does not altogether
+disallow) yet if even in those I have exceeded, 'tis fit that I should
+declare, that it was not done by YOUR Directions. For it is most
+unreasonable, that YOU should undergo the _imputation_ of the _faults_ of
+my _Conjectures_, seeing YOU can receive so _small advantage_ of reputation
+by the _sleight Observations_ of
+
+YOUR most humble and
+most faithful Servant
+
+ROBERT HOOKE.
+
+       *       *       *       *       *
+
+
+THE
+
+PREFACE.
+
+It is the great prerogative of Mankind above other Creatures, that we are
+not only able to _behold_ the works of Nature, or barely to _sustein_ our
+lives by them, but we have also the power of _considering_, _comparing_,
+_altering_, _assisting_, and _improving_ them to various uses. And as this
+is the peculiar priviledge of humane Nature in general, so is it capable of
+being so far advanced by the helps of Art, and Experience, as to make some
+Men excel others in their Observations, and Deductions, almost as much as
+they do Beasts. By the addition of such _artificial Instruments_ and
+_methods_, there may be, in some manner, a reparation made for the
+mischiefs, and imperfection, mankind has drawn upon it self, by negligence,
+and intemperance, and a wilful and superstitious deserting the Prescripts
+and Rules of Nature, whereby every man, both from a deriv'd corruption,
+innate and born with him, and from his breeding and converse with men, is
+very subject to slip into all sorts of errors.
+
+The only way which now remains for us to recover some degree of those
+former perfections, seems to be, by rectifying the operations of the
+_Sense_, the _Memory_, and _Reason_, since upon the evidence, the
+_strength_, the _integrity_, and the _right correspondence_ of all these,
+all the light, by which our actions are to be guided is to be renewed, and
+all our command over things it to be establisht.
+
+It is therefore most worthy of our consideration, to recollect their
+several defects, that so we may the better understand how to supply them,
+and by what assistances we may _inlarge_ their power, and _secure_ them in
+performing their particular duties.
+
+As for the actions of our _Senses_, we cannot but observe them to be in
+many particulars much outdone by those of other Creatures, and when at
+best, to be far short of the perfection they seem capable of: And these
+infirmities of the Senses arise from a double cause, either from the
+_disproportion of the Object to the Organ_, whereby an infinite number of
+things can never enter into them, or else from _error in the Perception_,
+that many things, which come within their reach, are not received in a
+right manner.
+
+The like frailties are to be found in the _Memory;_ we often let many
+things _slip away_ from us, which deserve to be retain'd, and of those
+which we treasure up, a great part is either _frivolous_ or _false_; and if
+good, and substantial, either in tract of time _obliterated_, or at best so
+_overwhelmed_ and buried under more frothy notions, that when there is need
+of them, they are in vain sought for.
+
+The two main foundations being so deceivable, it is no wonder, that all
+the succeeding works which we build upon them, of arguing, concluding,
+defining, judging, and all the other degrees of Reason, are lyable to the
+same imperfection, being, at best, either vain, or uncertain: So that the
+errors of the _understanding_ are answerable to the two other, being
+defective both in the quantity and goodness of its knowledge; for the
+limits, to which our thoughts are confin'd, are small in respect of the
+vast extent of Nature it self; some parts of it are _too large_ to be
+comprehended, and some _too little_ to be perceived. And from thence it
+must follow, that not having a full sensation of the Object, we must be
+very lame and imperfect in our conceptions about it, and in all the
+proportions which we build upon it; hence, we often take the _shadow_ of
+things for the _substance_, small _appearances_ for good _similitudes_,
+_similitudes_ for _definitions;_ and even many of those, which we think, to
+be the most solid definitions, are rather expressions of our own misguided
+apprehensions then of the true nature of the things themselves.
+
+The effects of these imperfections are manifested in different ways,
+according to the temper and disposition of the several minds of men, some
+they incline to _gross ignorance_ and stupidity, and others to a
+_presumptuous imposing_ on other mens Opinions, and a _confident
+dogmatizing_ on matters, whereof there it no assurance to be given.
+
+Thus all the uncertainty, and mistakes of humane actions, proceed either
+from the narrowness and wandring of our _Senses_, from the slipperiness or
+delusion of our _Memory_, from the confinement or rashness of our
+_Understanding_, so that 'tis no wonder, that our power over natural causes
+and effects is so slowly improv'd, seeing we are not only to contend with
+the obscurity and _difficulty of the things_ whereon we work and think, but
+even the _forces of our own minds_ conspire to betray us.
+
+These being the dangers in the process of humane Reason, the remedies of
+them all can only proceed from the _real_, the _mechanical_, the
+_experimental_ Philosophy, which has this advantage over the Philosophy of
+_discourse_ and _disputation_, that whereas that chiefly aims at the
+subtilty of its Deductions and Conclusions, without much regard to the
+first ground-work, which ought to be well laid on the Sense and Memory; so
+this intends the right ordering of them all, and the making them
+serviceable to each other.
+
+The first thing to be undertaken in this weighty work, is a _watchfulness
+over the failings_ and an _inlargement of the dominion_, of the Senses.
+
+To which end it is requisite, first, That there should be a _scrupulous_
+choice, and a _strict examination_, of the reality, constancy, and
+certainty of the Particulars that we admit: This is the first rise whereon
+truth is to begin, and here the most severe, and most impartial diligence,
+must be imployed; the storing up of all, without any regard to evidence or
+use, will only tend to darkness and confusion. We must not therefore esteem
+the riches of our Philosophical treasure by the _number_ only, but chiefly
+by the _weight_; the most _vulgar_ Instances are not to be neglected, but
+above all, the most _instructive_ are to be entertain'd; the footsteps of
+Nature are to be trac'd, not only in her _ordinary course_, but when she
+seems to be put to her shifts, to make many _doublings_ and _turnings_, and
+to use some kind of art in indeavouring to avoid our discovery.
+
+The next care to be taken, in respect of the Senses, is a supplying of
+their infirmities with _Instruments_, and, as it were, the adding of
+_artificial Organs_ to the _natural_; this in one of them has been of late
+years accomplisht with prodigious benefit to all sorts of useful knowledge,
+by the invention of Optical Glasses. By the means of _Telescopes_, there is
+nothing so _far distant_ but may be represented to our view; and by the
+help of _Microscopes_, there is nothing so _small_, as to escape our
+inquiry; hence there is a new visible World discovered to the
+understanding. By this means the Heavens are open'd, and a vast number of
+new Stars, and new Motions, and new Productions appear in them, to which
+all the ancient Astronomers were utterly Strangers. By this the Earth it
+self, which lyes so neer us, under our feet, shews quite a new thing to us,
+and in every _little particle_ of its matter; we now behold almost as great
+a variety of Creatures, as we were able before to reckon up in the whole
+_Universe_ it self.
+
+It seems not improbable, but that by these helps the subtilty of the
+composition of Bodies, the structure of their parts, the various texture of
+their matter, the instruments and manner of their inward motions, and all
+the other possible appearances of things, may come to be more fully
+discovered; all which the ancient _Peripateticks_ were content to
+comprehend in two general and (unless further explain'd) useless words of
+_Matter_ and _Form_. From whence there may arise many admirable advantages,
+towards the increase of the _Operative_, and the _Mechanick_ Knowledge, to
+which this Age seems so much inclined, because we may perhaps be inabled to
+discern all the secret workings of Nature, almost in the same manner as we
+do those that are the productions of Art, and are manag'd by Wheels, and
+Engines, and Springs, that were devised by humane Wit.
+
+In this kind I here present to the World my imperfect Indeavours; which
+though they shall prove no other way considerable, yet, I hope, they may be
+in some measure useful to the main Design of a _reformation_ in Philosophy,
+if it be only by shewing, that there it not so much requir'd towards it,
+any strength of _Imagination_, or exactness of _Method_, or depth of
+_Contemplation_ (though the addition of these, where they can be had, must
+needs produce a much more perfect composure) as a sincere _Hand_, and a
+_faithful_ Eye, to examine, and to record, the things themselves as they
+appear.
+
+And I beg my Reader, to let me take the boldness to assure him, that in
+this present condition of knowledge, a man so qualified, as I have
+indeavoured to be, only with resolution, and integrity, and plain
+intentions of imploying his _Senses_ aright, may venture to compare the
+reality and the usefulness of his services, towards the true Philosophy,
+with those of other men, that are of much stronger, and more acute
+_speculations_, that shall not make use of the same method by the Senses.
+
+The truth is, the Science of Nature has been already too long made only a
+work of the _Brain_ and the _Fancy_: It is now high time that it should
+return to the plainness and soundness of _Observations_ on _material_ and
+_obvious_ things. It is said of great Empires, That _the best way to
+preserve them from decay, is to bring them back to the first Principles,
+and Arts, on which they did begin_. The same is undoubtedly true in
+Philosophy, that by wandring far away into _invisible Notions_, has almost
+quite destroy'd it self, and it can never be recovered, or continued, but
+by returning into the same _sensible paths_, in which it did at first
+proceed.
+
+If therefore the Reader expects from me any infallible Deductions, or
+certainty of _Axioms_, I am to say for my self, that those stronger Works
+of Wit and Imagination are above my weak Abilities; or if they had not been
+so, I would not have made use of them in this present Subject before me:
+Whenever he finds that I have ventur'd at any small Conjectures, at the
+causes of the things that I have observed, I beseech him to look, upon them
+only as _doubtful Problems_, and _uncertain ghesses_, and not as
+unquestionable Conclusions, or matters of unconfutable Science; I have
+produced nothing here, with intent to bind his understanding to an
+_implicit_ consent; I am so far from that, that I desire him, not
+absolutely to rely upon these Observations of my eyes, if he finds them
+contradicted by the future Ocular Experiments of other and impartial
+Discoverers.
+
+As for my part, I have obtained my end, if these my small Labours shall be
+thought fit to take up some place in the large stock, of _natural
+Observations_, which so many hands are busie in providing. If I have
+contributed the _meanest foundations_ whereon others may raise nobler
+_Superstructures_, I am abundantly satisfied; and all my ambition is, that
+I may serve to the great Philosophers of this Age, as the makers and the
+grinders of my Glasses did to me; that I may prepare and furnish them with
+some _Materials_, which they may afterwards _order_ and _manage_ with
+better skill, and to far greater advantage.
+
+The next remedies in this universal cure of the Mind are to be applyed to
+the _Memory_, and they are to consist of such Directions as may inform us,
+what things are best to be _stor'd up_ for our purpose, and which is the
+best way of so _disposing_ them, that they may not only be _kept in
+safety_, but ready and convenient, to be at any time _produc'd_ for use, as
+occasion shall require. But I will not here prevent my self in what I may
+say in another Discourse, wherein I shall make an attempt to propose some
+Considerations of the manner of compiling a Natural and Artificial History,
+and of so ranging and registring its Particulars into Philosophical Tables,
+as may make them most useful for the raising of _Axioms_ and _Theories_.
+
+The last indeed is the most _hazardous_ Enterprize, and yet the most
+_necessary_; and that is, to take such care that the _Judgment_ and the
+_Reason_ of Man (which is the third Faculty to be repair'd and improv'd)
+should receive such assistance, as to avoid the dangers to which it it by
+nature most subject. The Imperfections, which I have already mention'd, to
+which it is lyable, do either belong to the _extent_, or the _goodness_ of
+its knowledge; and here the difficulty is the greater, least that which may
+be thought a _remedy_ for the one should prove _destructive_ to the other,
+least by seeking to inlarge our Knowledge, we should render it weak, and
+uncertain; and least by being too scrupulous and exact about every
+Circumstance of it, we should confine and streighten it too much.
+
+In both these the middle wayes are to be taken, nothing it to be_
+omitted_, and yet every thing to pass a _mature deliberation_: No
+_Intelligence_ from Men of all Professions, and quarters of the World, to
+be _slighted_, and yet all to be so _severely examin'd_, that there remain
+no room for doubt or instability; much _rigour_ in admitting, much
+_strictness_ in comparing, and above all, much _slowness_ in debating, and
+_shyness_ in determining, is to be practised. The _Understanding_ is to
+_order_ all the inferiour services of the lower Faculties; but yet it is to
+do this only as a _lawful Master_, and not at a _Tyrant._ It must not
+_incroach_ upon their Offices, nor take upon it self the employments which
+belong to either of them. It must _watch_ the irregularities of the Senses,
+but it must not go before them, or _prevent_ their information. It must
+_examine_, _range_, and _dispose_ of the bank which it laid up in the
+Memory: but it must be sure to make _distinction_ between the _sober_ and
+_well collected heap_, and the _extravagant Ideas_, and _mistaken Images_,
+which there it may sometimes light upon. So many are the _links_, upon
+which the true Philosophy depends, of which, if any one be _loose_, or
+_weak_, the whole _chain_ is in danger of being dissolv'd; it is to _begin_
+with the Hands and Eyes, and to _proceed_ on through the Memory, to be
+_continued_ by the Reason; nor is it to stop there, but to _come about_ to
+the Hands and Eyes again, and so, by a _continual passage round_ from one
+Faculty to another, it is to be maintained in life and strength, as much as
+the body of man it by the _circulation_ of the blood through the several
+parts of the body, the Arms, the Feet, the Lungs, the Heart, and the Head.
+
+If once this method were followed with diligence and attention, there is
+nothing that lyes within the power of human Wit (or which is far more
+effectual) of human Industry, which we might not compass; we might not only
+hope for Inventions to equalize those of _Copernicus_, _Galileo_,
+_Gilbert_, _Harvy_, and of others, whose Names are almost lost, that were
+the Inventors of _Gun-powder_, the _Seamans Compass_, _Printing_,
+_Etching_, _Graving_, _Microscopes_, &c. but multitudes that may far exceed
+them: for even those discoveries seem to have been the products of some
+such method, though but imperfect; What may not be therefore expected from
+it if thoroughly prosecuted? _Talking_ and _contention of Arguments_ would
+soon be turn'd into _labours_; all the fine _dreams_ of Opinions, and
+_universal metaphysical natures_, which the luxury of subtil Brains has
+devis'd, would quickly vanish, and give place to _solid Histories_,
+_Experiments_ and _Works._ And as at first, mankind _fell_ by _tasting_ of
+the forbidden Tree of Knowledge, so we, their Posterity, may be in part
+_restor'd_ by the same way, not only by _beholding_ and _contemplating_,
+but by _tasting_ too those fruits of Natural knowledge, that were never yet
+forbidden.
+
+From hence the World may be assisted with _variety_ of Inventions, _new_
+matter for Sciences may be _collected_, the _old improv'd_, and their
+_rust_ rubb'd away; and as it is by the benefit of Senses that we receive
+all our Skill in the works of Nature, so they also may be wonderfully
+benefited by it, and may be guided to an easier and more exact performance
+of their Offices; 'tis not unlikely, but that we may find out wherein our
+Senses are deficient, and as easily find wayes of repairing them.
+
+The Indeavours of Skilful men have been most conversant about the
+assistance of the Eye, and many noble Productions have followed upon it;
+and from hence we may conclude, that there it a way open'd for advancing
+the operations, not only of all the other Senses, but even of the Eye it
+self; that which has been already done ought not to content us, but rather
+to incourage us to proceed further, and to attempt greater things in the
+same, and different wayes.
+
+'Tis not unlikely, but that there may be yet invented several other helps
+for the eye, at much exceeding those already found, as those do the bare
+eye, such as by which we may perhaps be able to discover _living Creatures_
+in the Moon, or other Planets, the _figures_ of the compounding Particles
+of matter, and the particular _Schematisms_ and _Textures_ of Bodies.
+
+And as _Glasses_ have highly promoted our _seeing_, so 'tis not
+improbable, but that there may be found many _Mechanical Inventions_ to
+improve our other Senses, of _hearing_, _smelling_, _tasting_, _touching._
+'Tis not impossible to hear a _whisper_ a _furlongs_ distance, it having
+been already done; and perhaps the nature of the thing would not make it
+more impossible, though that furlong should be ten times multiply'd. And
+though some famous Authors have affirm'd it impossible to hear through the
+_thinnest plate_ of _Muscovy-glass_; yet I know a way, by which 'tis easie
+enough to hear one speak through a _wall a yard thick_. It has not been yet
+thoroughly examin'd, how far _Otocousticons_ may be improv'd, nor what
+other wayes there may be of _quickning_ our hearing, or _conveying_ sound
+through _other bodies_ then the _Air_: for that that it not the only
+_medium_, I can assure the Reader, that I have, by the help of a _distended
+wire_, propagated the sound to a very considerable distance in an
+_instant_, or with as seemingly quick a motion as that of light, at least,
+incomparably swifter then that, which at the same time was propagated
+through the Air; and this not only in a straight line, or direct, but in
+one bended in many angles.
+
+Nor are the other three so perfect, but that _diligence_, _attention_, and
+many _mechanical contrivances_, may also highly improve them. For since the
+sense of _smelling_ seems to be made by the _swift passage_ of the _Air_
+(_impregnated_ with the steams and _effluvia_ of several odorous Bodies)
+through the grisly _meanders_ of the Nose whose surfaces are _cover'd_ with
+a very sensible _nerve_, and _moistned_ by a _transudation_ from the
+_processus mamillares_ of the Brain, and some adjoyning _glandules_, and by
+the moist _steam_ of the _Lungs_, with a Liquor convenient for the
+reception of those _effluvia_ and by the adhesion and mixing of those
+steams with that liquor, and thereby affecting the nerve, or perhaps by
+insinuating themselves into the juices of the brain, after the same manner,
+as I have in the following Observations intimated, the parts of Salt to
+pass through the skins of Effs, and Frogs. Since, I say, smelling seems to
+be made by some such way, 'tis not improbable, but that some contrivance,
+for making a great quantity of Air pass quick through the Nose, might at
+much promote the sense of smelling, as the any wayes hindring that passage
+does dull and destroy it. Several tryals I have made, both of hindring and
+promoting this sense, and have succeeded in some according to expectation;
+and indeed to me it seems capable of being improv'd, for the judging of the
+constitutions of many Bodies. Perhaps we may thereby also judge (as other
+Creatures seem to do) what is wholsome, what poyson; and in a word, what
+are the specifick properties of Bodies.
+
+There may be also some other mechanical wayes found out, of sensibly
+perceiving the _effluvia_ of Bodies; several Instances of which, were it
+here proper, I could give of Mineral steams and exhalations; and it seems
+not impossible, but that by some such wayes improved, may be discovered,
+what Minerals lye buried under the Earth, without the trouble to dig for
+them; some things to confirm this Conjecture may be found in _Agricola_,
+and other Writers of Minerals, speaking of the Vegetables that are apt to
+thrive, or pine, in those steams.
+
+Whether also those steams, which seem to issue out of the Earth, and mix
+with the Air (and so to precipitate some _aqueous_ Exhalations, wherewith
+'tis impregnated) may not be by some way detected before they produce the
+effect, seems hard to determine; yet something of this kind I am able to
+discover, by an Instrument I contriv'd to shew all the minute variations in
+the pressure of the Air; by which I constantly find, that before, and
+during the time of rainy weather, the pressure of the Air is less, and in
+_dry weather_, but especially when an _Eastern Wind_ (which having past
+over vast tracts of Land is heavy with Earthy Particles) blows, it is much
+more, though these changes are varied according to very odd Laws.
+
+    The Instrument is this. I prepare a pretty capaceous Bolt-head AB, with
+    a small stem about two foot and a half long DC; upon the end of this D
+    I put on a small bended Glass, or brazen _syphon_ DEF (open at D, E and
+    F, but to be closed with cement at F and E, as occasion serves) whose
+    stem F should be about six or eight inches long, but the bore of it not
+    above half an inch diameter, and very even; these I fix very strongly
+    together by the help of very hard Cement, and then fit the whole Glass
+    ABCDEF into a long Board, or Frame, in such manner, that almost half
+    the head AB may lye buried in a concave Hemisphere cut into the Board
+    RS; then I place it so on the Board RS, as is exprest in the first
+    figure of the first Scheme; and fix it very firm and steady in that
+    posture, so as that the weight of the _Mercury_ that is afterwards to
+    be put into it, may not in the least shake or stir it; then drawing a
+    line XY on the Frame RT, so that it may divide the ball into two equal
+    parts, or that it may pass, as 'twere, through the center of the ball.
+    I begin from that, and divide all the rest of the Board towards UT into
+    inches, and the inches between the 25 and the end E (which need not be
+    above two or three and thirty inches distant from the line XY) I
+    subdivide into Decimals; then stopping the end F with soft Cement, or
+    soft Wax, I invert the Frame, placing the head downwards, and the
+    Orifice E upwards; and by it, with a small Funnel, I fill the whole
+    Glass with Quicksilver; then by stopping the small Orifice E with my
+    finger, I oftentimes erect and invert the whole Glass and Frame, and
+    thereby free the Quicksilver and Glass from all the bubbles or parcels
+    of lurking Air; then inverting it as before, I fill it top full with
+    clear and well strain'd Quicksilver, and having made ready a small ball
+    of pretty hard Cement, by heat made very soft, I press it into the hole
+    E, and thereby stop it very fast; and to secure this Cement from flying
+    out afterward, I bind over it a piece of Leather, that is spread over
+    in the inside with Cement, and wound about it while the Cement is hot:
+    Having thus softned it, I gently erect again the Glass after this
+    manner: I first let the Frame down edge-wayes, till the edge RV touch
+    the Floor, or ly horizontal; and then in that edging posture raise the
+    end RS; this I do, that if there chance to be any Air hidden in the
+    small Pipe E, it may ascend into the Pipe F, and not into the Pipe DC:
+    Having thus erected it, and hung it by the hole Q, or fixt it
+    perpendicularly by any other means, I open the end F, and by a small
+    _Syphon_ I draw out the _Mercury_ so long, till I find the surface of
+    it AB in the head to touch exactly the line XY; at which time I
+    immediately take away the _Syphon_, and if by chance it be run somewhat
+    below the line XY, by pouring in gently a little _Mercury_ at F, I
+    raise it again to its desired height, by this contrivance I make all
+    the sensible rising and falling of the _Mercury_ to be visible in the
+    surface of the _Mercury_ in the Pipe F, and scarce any in the head AB.
+    But because there really is some small change of the upper surface
+    also, I find by several Observations how much it rises in the Ball, and
+    falls in the Pipe F, to make the distance between the two surfaces an
+    inch greater then it was before; and the measure that it falls in the
+    Pipe is the length of the inch by which I am to mark the parts of the
+    Tube F, or the Board on which it lyes, into inches and Decimals: Having
+    thus justned and divided it, I have a large Wheel MNOP, whose outmost
+    limb is divided into two hundred equal parts; this by certain small
+    Pillars is fixt on the Frame RT, in the manner exprest in the Figure.
+    In the middle of this, on the back side, in a convenient frame, is
+    placed a small Cylinder, whose circumference is equal to twice the
+    length of one of those divisions, which I find answer to an inch of
+    ascent, or descent, of _Mercury_: This Cylinder I, is movable on a very
+    small Needle, on the end of which is fixt a very light Index KL, all
+    which are so pois'd on the Axis, or Needle, that no part is heavier
+    then another: Then about this Cylinder is wound a small Clew of Silk,
+    with two small steel Bullets at each end of it GH; one of these, which
+    is somewhat the heavier, ought to be so big, as freely to move to and
+    fro in the Pipe F; by means of which contrivance, every the least
+    variation of the height of the _Mercury_ will be made exceeding visible
+    by the motion to and fro of the small Index KL.
+
+But this is but one way of discovering the _effluvia_ of the Earth mixt
+with the Air; there may be, perhaps many others, witness the _Hygroscope_,
+an Instrument whereby the watery steams volatile in the Air are discerned,
+which the Nose it self is not able to find. This I have describ'd in the
+following Tract in the Description of the Beard of a wild Oat. Others
+there, are, may be discovered both by the Nose, and by other wayes also.
+Thus the _smoak_ of burning _Wood_ is _smelt_, _seen_, and sufficiently
+_felt_ by the eyes: The _fumes_ of burning _Brimstone_ are _smelt_ and
+discovered also by the destroying the Colours of Bodies, as by the
+_whitening of a red Rose_: And who knows, but that the Industry of man,
+following this method, may find out wayes of improving this sense to as
+great a degree of perfection at it is in any Animal, and perhaps yet
+higher.
+
+'Tis not improbable also, but that our _taste_ may be very much improv'd
+either by _preparing_ our taste for the Body, as, after eating _bitter_
+things, _Wine_, or other _Vinous liquors_, are more sensibly tasted; or
+else by _preparing_ Bodies for our tast; as the dissolving of Metals with
+acid Liquors, make them tastable, which were before altogether insipid;
+thus _Lead_ becomes _sweeter_ then Sugar, and _Silver_ more _bitter_ then
+Gall, _Copper_ and _Iron_ of most _loathsome_ tasts. And indeed the
+business of this sense being to discover the presence of dissolved Bodies
+in Liquors put on the Tongue, or in general to discover that a fluid body
+has some solid body dissolv'd in it, and what they are; whatever
+contrivance makes this discovery improves this sense. In this kind the
+mixtures of Chymical Liquors afford many Instances; as the sweet Vinegar
+that is impregnated with Lead may be discovered to be so by the affusion of
+a little of an _Alcalizate solution_: The bitter liquor of _Aqua fortis_
+and _Silver_ may be discover'd to be charg'd with that Metal, by laying in
+it some plates of Copper: 'Tis not improbable also, but there may be
+multitudes of other wayes of discovering the parts dissolv'd, or dissoluble
+in liquors; and what is this discovery but a kind of _secundary tasting_.
+
+'Tis not improbable also, but that the sense of _feeling_ may be highly
+improv'd, for that being a sense that judges of the more _gross_ and
+_robust motions_ of the _Particles_ of _Bodies_, seems capable of being
+improv'd and assisted very many wayes. Thus for the distinguishing of
+_Heat_ and _Cold_, the _Weather-glass_ and _Thermometer_, which I have
+describ'd in this following Treatise, do exceedingly perfect it; by each of
+which the least variations of heat or cold, which the most Acute sense is
+not able to distinguish, are manifested. This is oftentimes further
+promoted also by the help of _Burning-glasses_, and the like, which collect
+and unite the radiating heat. Thus the _roughness_ and _smoothness_ of a
+Body is made much more sensible by the help of a _Microscope_, then by the
+most _tender_ and _delicate Hand_. Perhaps, a Physitian might, by several
+other _tangible_ proprieties, discover the constitution of a Body as well
+as by the _Pulse_. I do but instance in these, to shew what possibility
+there may be of many others, and what probability and hopes there were of
+finding them, if this method were followed; for the Offices of the five
+Senses being to detect either the _subtil_ and _curious Motions_ propagated
+through all _pellucid_ or perfectly _homogeneous_ Bodies; Or the more
+_gross_ and _vibrative Pulse_ communicated through the _Air_ and all other
+convenient _mediums_, whether fluid or solid: Or the _effluvia_ of Bodies
+_dissolv'd_ in the _Air_; Or the _particles_ of bodies _dissolv'd_ or
+_dissoluble_ in _Liquors_, or the more _quick_ and _violent shaking motion_
+of _heat_ in all or any of these: whatsoever does any wayes promote any of
+these kinds of _criteria_, does afford a way of improving some one sense.
+And what a multitude of these would a diligent Man meet with in his
+inquiries? And this for the helping and promoting the _sensitive faculty_
+only.
+
+Next, as for the _Memory_, or _retentive faculty_, we may be sufficiently
+instructed from the _written Histories_ of _civil actions_, what great
+assistance may be afforded the Memory, in the committing to writing things
+observable in _natural operations_. If a Physitian be therefore accounted
+the more able in his Faculty, because he has had long experience and
+practice, the remembrance of which, though perhaps very imperfect, does
+regulate all his after actions: What ought to be thought of that man, that
+has not only a perfect _register_ of his own experience, but it grown _old_
+with the experience of many hundreds of years, and many thousands of men.
+
+And though of late, men, beginning to be sensible of this convenience,
+have here and there registred and printed some few _Centuries_, yet for the
+most part they are set down very lamely and imperfectly, and, I fear, many
+times not so truly, they seeming, several of them, to be design'd more for
+_Ostentation_ then _publique use_: For, not to instance, that they do, for
+the most part, omit those Experiences they have made, wherein their
+Patients have miscarried, it is very easie to be perceiv'd, that they do
+all along _hyperbolically extol_ their own Prescriptions, and vilifie those
+of others. Notwithstanding all which, these kinds of Histories are
+generally esteem'd useful, even to the ablest Physitian.
+
+What may not be expected from the _rational_ or _deductive Faculty_ that
+is furnisht with such _Materials_, and those so readily _adapted_, and
+rang'd for use, that in a moment, at 'twere, thousands of Instances,
+serving for the _illustration_, _determination_, or _invention_, of almost
+any inquiry, may be _represented_ even to the sight? How neer the nature of
+_Axioms_ must all those _Propositions_ be which are examin'd before so many
+_Witnesses_? And how difficult will it be for any, though never so subtil
+an error in Philosophy, to _scape_ from being discover'd, after it has
+indur'd the _touch_, and so many other _tryals_?
+
+What kind of mechanical way, and physical invention also is there requir'd
+that might not this may be found out? The _Invention_ of a way to find the
+_Longitude_ of places is easily perform'd, and that to as great
+_perfection_ as is desir'd, or to at great an _accurateness_ as the
+_Latitude_ of places can be found at Sea; and perhaps yet also to a greater
+certainty then that has been hitherto found, as I shall very speedily
+freely manifest to the world. The way of _flying_ in the Air seems
+principally unpracticable, by reason of the _want of strength_ in _humane
+muscles_; if therefore that could be suppli'd, it were, I think, easie to
+make twenty contrivances to perform the office of _Wings_: What Attempts
+also I have made for the supplying that Defect, and my successes therein,
+which, I think, are wholly new, and not inconsiderable, I shall in another
+place relate.
+
+'Tis not unlikely also, but that _Chymists_, if they followed this method,
+might find out their so much sought for _Alkahest_. What an _universal
+Menstruum_, which dissolves all sorts of _Sulphureous Bodies_, I have
+discover'd (which hat not been before taken notice of as such) I have shewn
+in the sixteenth Observation.
+
+What a prodigious variety of Inventions in _Anatomy_ has this latter Age
+afforded, even in our own Bodies in the very _Heart_, by which we live, and
+the Brain, which is the seat of our knowledge of other things? witness all
+the excellent Works of _Pecquet_, _Bartholinus_, _Billius_, and many
+others; and at home, of Doctor _Harvy_, Doctor _Ent_, Doctor _Willis_,
+Doctor _Glisson_. In _Celestial Observations_ we have far exceeded all the
+Antients, even the _Chaldeans_ and _Egyptians_ themselves, whose _vast
+Plains_, _high Towers_, and _clear Air_, did not give them so great
+advantages over us, as have over them by our _Glasses_. By the help of
+which, they have been very much outdone by the famous _Galileo_,
+_Hevelius_, _Zulichem_; and our own Countrymen, Mr. _Rook_, Doctor _Wren_,
+and the great Ornament of our Church and Nation, the _Lord Bishop of
+Exeter_. And to say no more in _Aerial Discoveries_, there has been a
+wonderful progress made by the _Noble Engine_ of _the most Illustrious Mr.
+Boyle_, whom it becomes me to mention with all honour, not only as my
+particular Patron, but as the _Patron_ of _Philosophy_ it self; which he
+every day _increases_ by his _Labours_, and _adorns_ by his _Example_.
+
+The good success of all these _great Men_, and many others, and the now
+seemingly great _obviousness_ of most of their and divers other Inventions,
+which from the beginning of the world have been, as 'twere, trod on, and
+yet not minded till these last _inquisitive_ Ages (an Argument that there
+may be yet behind multitudes of the like) puts me in mind to recommend such
+Studies, and the prosecution of them by such methods, to the _Gentlemen_ of
+our Nation, whose _leisure_ makes them fit to _undertake_, and the _plenty_
+of their fortunes _to accomplish_, extraordinary things in this way. And I
+do not only propose this kind of _Experimental Philosophy_ as matter of
+high _rapture_ and _delight_ of the mind, but even as a _material_ and
+_sensible Pleasure_. So vast it the _variety of Objects_ which will come
+under their Inflections, so many _different wayes_ there are _of handling_
+them, so great is the _satisfaction_ of _finding_ out _new things_, that I
+dare compare the _contentment_ which they will injoy, not only to that of
+_contemplation_, but even to that which most men prefer of _the very Senses
+themselves_.
+
+And if they will please to take any incouragement from so mean and so
+imperfect endeavours as mine, upon my own experience, I can assure them,
+without arrogance, That there has not been any inquiry or Problem in
+_Mechanicks_, that I have hitherto propounded to my self, but by a certain
+method (which I may on some other opportunity explain) I have been able
+presently to examine the possibility of it; and if so, as easily to
+excogitate divers wayes of performing it: And indeed it is possible to do
+as much by _this method_ in _Mechanicks_, as by _Algebra_ can be perform'd
+in _Geometry_. Nor can I at all doubt, but that the same method is as
+applicable to _Physical Enquiries_, and as likely to find and reap thence
+at plentiful a crop of Inventions; and indeed there seems to be no subject
+so barren, but may with this good husbandry be highly improv'd.
+
+Toward the prosecution of this method in _Physical Inquiries_, I have here
+and there _gleaned_ up an _handful_ of Observations, in the collection of
+most of which I made use of _Microscopes_, and some other _Glasses_ and
+_Instruments_ that improve the sense; which way I have herein taken, not
+that there are not multitudes of useful and pleasant Observables, yet
+uncollected, obvious enough without the helps of Art, but only to promote
+the use of Mechanical helps for the Senses, both in the surveying the
+already visible World, and for the discovery of many others hitherto
+unknown, and to make us, with the great Conqueror, to be affected that we
+have not yet overcome one World when there are so many others to be
+discovered, every considerable improvement of _Telescopes_ or _Microscopes_
+producing new Worlds and _Terra-Incognita's_ to our view.
+
+The Glasses I used were of our English make, but though very good of the
+kind, yet far short of what might be expected, could we once find a way of
+making Glasses Elliptical, or of some more true shape; for though both
+_Microscopes_, and _Telescopes_, as they now are, will magnifie an Object
+about a thousand thousand times bigger then it appears to the naked eye;
+yet the Apertures of the Object-glasses are so very small, that very few
+Rays are admitted, and even of those few there are so many false, that the
+Object appears _dark_ and _indistinct_: And indeed these inconveniences are
+such, as seem inseparable from Spherical Glasses, even when most exactly
+made; but the way we have hitherto made use of for that purpose is so
+imperfect, that there may be perhaps ten wrought before one be made
+tolerably good, and most of those ten perhaps every one differing in
+goodness one from another, which is an Argument, that the way hitherto used
+is, at least, very uncertain. So that these Glasses have a double defect;
+the one, that very few of them are exactly true wrought; the other, that
+even of those that are best among them, none will admit a sufficient number
+of Rayes to magnifie the Object beyond a determinate bigness. Against which
+Inconveniences the only Remedies I have hitherto met with are these.
+
+    First, for _Microscopes_ (where the Object we view is near and within
+    our power) the best way of making it appear bright in the Glass, is to
+    cast a great quantity of light on it by means of _convex glasses_, for
+    thereby, though the aperture be very small, yet there will throng in
+    through it such multitudes, that an Object will by this means indure to
+    be magnifi'd as much again as it would be without it. The way for doing
+    which is this. I make choice of some Room that has only one window open
+    to the South, and at about three or four foot distance from this
+    Window, on a Table, I place my _Microscope_, and then so place either a
+    round Globe of Water, or a very deep clear_ plano convex_ Glass (whose
+    convex side is turn'd towards the Window) that there is a great
+    quantity of Rayes collected and thrown upon the Object: Or if the Sun
+    shine, I place a small piece of oyly Paper very near the Object,
+    between that and the light; then with a good large Burning-Glass I so
+    collect and throw the Rayes on the Paper, that there may be a very
+    great quantity of light pass through it to the Object; yet I so
+    proportion that light, that it may not singe or burn the Paper. Instead
+    of which Paper there may be made use of a small piece of Looking-glass
+    plate, one of whose sides is made rough by being rubb'd on a flat Tool
+    with very find sand, this will, if the heat be leisurely cast on it,
+    indure a much greater degree of heat, and consequently very much
+    augment a convenient light. By all which means the light of the Sun, or
+    of a Window, may be so cast on an Object, as to make it twice as light
+    as it would otherwise be without it, and that without any inconvenience
+    of glaring, which the immediate light of the Sun is very apt to create
+    in most Objects; for by this means the light is so equally diffused,
+    that all parts are alike inlightned; but when the immediate light of
+    the Sun falls on it, the reflexions from some few parts are so vivid,
+    that they drown the appearance of all the other, and are themselves
+    also, by reason of the inequality of light, indistinct, and appear only
+    radiant spots.
+
+    But because the light of the Sun, and also that of a Window, is in a
+    continual variation, and so many Objects cannot be view'd long enough
+    by them to be throughly examin'd; besides that, oftentimes the Weather
+    is so dark and cloudy, that for many dayes together nothing can be
+    view'd: And because also there are many Objects to be met with in the
+    night, which cannot so conveniently be kept perhaps till the day,
+    therefore to procure and cast a sufficient quantity of light on an
+    Object in the night, I thought of, and often used this, Expedient.
+
+    I procur'd me a small Pedestal, such as is describ'd in the fifth
+    Figure of the first _Scheme_ on the small Pillar AB, of which were two
+    movable Armes CD, which by means of the Screws EF, I could fix in any
+    part of the Pillar; on the undermost of these I plac'd a pretty large
+    Globe of Glass G, fill'd with exceeding clear Brine, stopt, inverted,
+    and fixt in the manner visible in the Figure; out of the side of which
+    Arm proceeded another Arm H, with many joynts; to the end of which was
+    fastned a deep plain _Convex glass_ I, which by means of this Arm could
+    be moved too and fro, and fixt in any posture. On the upper Arm was
+    placed a small Lamp K, which could be to mov'd upon the end of the Arm,
+    as to be set in a fit posture to give light through the Ball: By means
+    of this Instrument duly plac'd, as is exprest in the Figure, with the
+    small flame of a Lamp may be cast as great and convenient a light on
+    the Object as it will well indure; and being always constant, and to be
+    had at any time, I found most proper for drawing the representations of
+    those small Objects I had occasion to observe.
+
+    None of all which ways (though much beyond any other hitherto made use
+    of by any I know) do afford a sufficient help, but after a certain
+    degree of magnifying, they leave us again in the lurch. Hence it were
+    very desirable, that some way were thought of for making the
+    Object-glass of such a Figure as would conveniently bear a large
+    Aperture.
+
+As for _Telescopes_, the only improvement they seem capable of, is the
+increasing of their length; for the Object being remote, there is no
+thought of giving it a greater light then it has; and therefore to augment
+the. Aperture, the Glass must be ground of a very large sphere; for, by
+that means, the longer the Glass be, the bigger aperture will it bear, if
+the Glasses be of an equal goodness in their kind. Therefore a six will
+indure a much larger Aperture then a three foot Glass, and a sixty foot
+Glass will proportionably bear a greater Aperture then a thirty, and will
+as much excel it also as a six foot does a three foot, as I have
+experimentally observ'd in one of that length made by Mr. _Richard Reives_
+here at _London_, which will bear an Aperture above three inches over, and
+yet make the Object proportionably big and distinct; whereas there are very
+few thirty foot Glasses that will indure an Aperture of more then two
+inches over. So that for _Telescopes_, supposing we had a very ready way of
+making their Object Glasses of exactly spherical Surfaces, we might, by
+increasing the length of the Glass, magnifie the Object to any assignable
+bigness. And for performing both these, I cannot imagine any way more
+easie, and more exact, then by this following Engine, by means of which,
+any Glasses, of what length soever, may be speedily made. It seems the most
+easie, because with one and the same Tool may be with care ground an Object
+Glass, of any length or breadth requisite, and that with very little or no
+trouble in fitting the Engine, and without much skill in the Grinder. It
+seems to be the most exact, for to the very last stroke the Glass does
+regulate and rectifie the Tool to its exact Figure; and the longer or more
+the Tool and Glass are wrought together, the more exact will both of them
+be of the desir'd Figure. Further, the motions of the Glass and Tool do so
+cross each other, that there is not one point of eithers Surface, but has
+thousands of cross motions thwarting it, so that there can be no kind of
+Rings or Gutters made either in the Tool or Glass.
+
+    The contrivance of the Engine is, only to make the ends of two large
+    _Mandrils_ so to move, that the Centers of them may be at any
+    convenient distance asunder, and that the _Axis_ of the _Mandrils_
+    lying both in the same plain produc'd, may meet each other in any
+    assignable Angle; both which requisites may be very well perform'd by
+    the Engine describ'd in the third Figure of the first _Scheme_: where
+    AB signifies the Beam of a Lath fixt perpendicularly or Horizontally,
+    CD the two Poppet heads, fixt at about two foot distance, EF an Iron
+    _Mandril_, whose tapering neck F runs in an adapted tapering brass
+    Collar; the other end E runs on the point of a Screw G; in a convenient
+    place of this is fastned H a pully Wheel, and into the end of it, that
+    comes through the Poppet head C, is screwed a Ring of a hollow
+    _Cylinder_ K, or some other conveniently shap'd Tool, of what wideness
+    shall be thought most proper for the cize of Glasses, about which it is
+    to be imploy'd: As, for Object glasses, between twelve foot and an
+    hundred foot long, the Ring may be about six inches over, or indeed
+    somewhat more for those longer Glasses. It would be convenient also and
+    not very chargeable, to have four or five several Tools; as one for all
+    Glasses between an inch and a foot, one for all Glasses between a foot
+    and ten foot long, another for all between ten and an hundred, a fourth
+    for all between a hundred and a thousand foot long; and if Curiosity
+    shall ever proceed so far, one for all lengths between a thousand and
+    ten thousand foot long; for indeed the principle is such, that
+    supposing the _Mandrils_ well made, and of a good length, and supposing
+    great care be used in working and polishing them, I see no reason, but
+    that a Glass of a thousand, nay of ten thousand foot long, may be as
+    well made as one of ten; for the reason is the same, supposing the
+    _Mandrils_ and Tools be made sufficiently strong, so that they cannot
+    bend; and supposing the Glass, out of which they are wrought, be
+    capable of so great a regularity in its parts as to refraction: this
+    hollow _Cylinder_ K is to contain the Sand, and by being drove round
+    very quick to and fro by means of a small Wheel, which may be mov'd
+    with ones foot, serves to grind the Glass: The other _Mandril_ is
+    shap'd like this, but it has an even neck instead of a taper one, and
+    runs in a Collar, that by the help of a Screw and a joynt made like M
+    in the Figure, it can be still adjustned to the wearing or wasting
+    neck: into the end of this _Mandril_ is screwed a Chock N on which with
+    Cement or Glew is fastned the piece of Glass Q that is to be form'd;
+    the middle of which Glass is to be plac'd just on the edge of the Ring
+    and the Lath OP is to be set and fixt (by means of certain pieces and
+    screws the manner whereof will be sufficiently evidenc'd by the Figure)
+    in such an Angle as is requisite to the forming of such a Sphere as the
+    Glass is design'd to be of; the geometrical ground of which being
+    sufficiently plain, though not heeded before, I shall, for brevities
+    sake, pass over. This last _Mandril_ to be made (by means of the
+    former, or some other Wheel) to run round very swift also, by which two
+    cross motions the Glass cannot chuse (if care be us'd) but be wrought
+    into a most exactly spherical Surface.
+
+But because we are certain, from the _Laws of refraction_ (which I I have
+experimentally found to be so, by an Instrument I shall presently describe)
+that _the lines of the angles of Incidence are proportionate to the lines
+of the angles of Refraction_, therefore if Glasses could be made of those
+kind of Figures, or some other, such as the most incomparable _Des Cartes_
+has invented, and demonstrated in his Philosophical and Mathematical Works,
+we might hope for a much greater perfection of Opticks then can be
+rationally expected from spherical ones; for though, _caeteris paribus_, we
+find, that the larger the _Telescope_ Object Glasses are, and the shorter
+those of the _Microscope_, the better they magnify, yet both of them,
+beside such determinate dimensions, are by certain inconveniences rendred
+unuseful; for it will be exceeding _difficult_ to make and _manage_ a Tube
+above an _hundred foot long_, and it will be as difficult to _inlighten_ an
+Object less then an hundred part of an inch distant from the Object Glass.
+
+I have not as yet made any attempts of that kind, though I know two or
+three wayes, which, as far as I have yet considered, seem very probable,
+and may invite me to make a tryal as soon as I have an opportunity, of
+which I may hereafter perhaps acquaint the world. In the Interim, I shall
+describe the Instrument I even now mention'd, by which the _refraction_ of
+all kinds of Liquors may be most exactly measur'd, thereby to give the
+curious an opportunity of making what further tryals of that kind they
+shall think requisite to any of their intended tryals; and to let them see
+that the laws of Refraction are not only notional.
+
+    The Instrument consisted of five Rulers, or long pieces placed
+    together, after the manner exprest in the second Figure of the first
+    _Scheme_, where AB denotes a straight piece of wood about six foot and
+    two inches long, about three inches over, and an inch and half thick,
+    on the back side of which was hung a small plummet by a line stretcht
+    from top to bottom, by which this piece was set exactly upright, and so
+    very firmly fixt; in the middle of this was made a hole or center, into
+    which one end of a hollow cylindrical brass Box CC, fashion'd as I
+    shall by and by describe, was plac'd, and could very easily and truly
+    be mov'd to and fro; the other end of this Box being put into, and
+    moving in, a hole made in a small arm DD; into this box was fastned the
+    long Ruler EF, about three foot and three or four inches long, and at
+    three foot from the above mention'd Centers PP was a hole E, cut
+    through, and cross'd with two small threads, and at the end of it was
+    fixt a small sight G, and on the back side of it was fixt a small Arm
+    H, with a Screw to fix it in any place on the Ruler LM; this Ruler LM
+    was mov'd on the Center B (which was exactly three foot distance from
+    the middle Center P) and a line drawn through the middle of it LM, was
+    divided by a Line of cords into some sixty degrees, and each degree was
+    subdivided into minutes, so that putting the cross of the threads in E
+    upon any part of this divided line, I presently knew what Angle the two
+    Rules AB and EF made with each other, and by turning the Screw in H, I
+    could fix them in any position. The other Ruler also RS was made much
+    after the same manner, only it was not fixt to the hollow cylindrical
+    Box, but, by means of two small brass Armes or Ears, it mov'd on the
+    Centers of it; this also, by means of the cross threads in the hole S,
+    and by a Screw in K, could be fastned on any division of another line
+    of cords of the same radius drawn on NO. And so by that means, the
+    Angle made by the two Rulers, AB and RS, was also known. The Brass box
+    CC in the middle was shap'd very much like the Figure X, that is, it
+    was a cylindrical Box stopp'd close at either end, off of which a part
+    both of the sides and bottomes was cut out, so that the Box, when the
+    Pipe and that was joyned to it, would contain the Water when fill'd
+    half full, and would likewise, without running over, indure to be
+    inclin'd to an Angle, equal to that of the greatest refraction of
+    Water, and no more, without running over. The Ruler EF was fixt very
+    fast to the Pipe V, so that the Pipe V directed the length of the Ruler
+    EF, and the Box and Ruler were mov'd on the Pin TT, so as to make any
+    desirable Angle with the Ruler AB. The bottom of this Pipe V was stop'd
+    with a small piece of exactly plain Glass, which was plac'd exactly
+    perpendicular to the Line of direction, or _Axis_ of the Ruler EF. The
+    Pins also TT were drill'd with small holes through the _Axis_, and
+    through those holes was stretcht and fastned a small Wire. There was
+    likewise a small Pipe of Tin loosly put on upon the end of V, and
+    reaching down to the sight G; the use of which was only to keep any
+    false Rayes of light from passing through the bottom of V, and only
+    admitting such to pass as pierced through the sight G: All things being
+    placed together in the manner describ'd in the Figure; that is, the
+    Ruler AB being fixt perpendicular, I fill'd the Box CC with Water, or
+    any other Liquor, whose refraction I intended to try, till the Wire
+    passing through the middle of it were just covered: then I moved and
+    fixt the Ruler FE at any assignable Angle, and placed the flame of a
+    Candle just against the sight G; and looking through the sight I, I
+    moved the Ruler RS to and fro, till I perceived the light passing
+    through G to be covered, as 'twere, or divided by the dark Wire passing
+    through PP: then turning the Screw in K, I fixt it in that posture: And
+    through the hole S, I observed what degree and part of it was cut by
+    the cross threads in S. And this gave me the Angle of Inclination, APS
+    answering to the Angle of Refraction BPE: for the surface of the Liquor
+    in the Box will be alwayes horizontal, and consequently AB will be a
+    perpendicular to it; the Angle therefore APS will measure, or be the
+    Angle of Inclination in the Liquor; next EPB must be the Angle of
+    Refraction, for the Ray that passes through the sight G, passes also
+    perpendicularly through the Glass _Diaphragme_ at F, and consequently
+    also perpendicularly through the lower surface of the Liquor contiguous
+    to the Glass, and therefore suffers no refraction till it meet with the
+    horizontal surface of the Liquor in CC, which is determined by the two
+    Angles.
+
+By means of this Instrument I can with _little trouble_, and a very small
+quantity of any _Liquor_, examine, most accurately, the _refraction_ of it
+not only for one inclination, but for all; and thereby am inabled to make
+very accurate Tables; several of which I have also experimentally made, and
+find, that _Oyl of Turpentine_ has a much greater Refraction then _Spirit
+of Wine_, though it be _lighter_; and that _Spirit of Wine_ has a greater
+Refraction then _Water_, though it be lighter also; but that _salt Water_
+also has a greater Refraction then _fresh_, though it be _heavier_: but
+_Allum water_ has a less refraction then common _Water_, though heavier
+also. So that it seems, as to the _refraction_ made in a Liquor, the
+_specifick gravity_ is of no efficacy. By this I have also found that look
+what _proportion _the _Sine_ of the Angle of _one Inclination_ has to the
+_Sine_ of the Angle of _Refraction_, correspondent to it, the same
+_proportion_ have all the _Sines_ of other Inclinations to the _Sines_ of
+their appropriate Refractions.
+
+    My way for measuring how much a Glass magnifies an Object, plac'd at a
+    convenient distance from my eye, is this. Having rectifi'd the
+    _Microscope_, to see the desir'd Object through it very distinctly, at
+    the same time that I look upon the Object through the Glass with one
+    eye, I look upon other Objects at the same distance with my other bare
+    eye; by which means I am able, by the help of a _Ruler_ divided into
+    inches and small parts, and laid on the _Pedestal_ of the _Microscope_,
+    to cast, as it were, the magnifi'd appearance of the Object upon the
+    Ruler, and thereby exactly to measure the Diameter it appears of
+    through the Glass, which being compar'd with the Diameter it appears of
+    to the naked eye, will easily afford the quantity of its magnifying.
+
+    The _Microscope_, which for the most part I made use of, was shap'd
+    much like that in the sixth Figure of the first _Scheme_, the Tube
+    being for the most part not above six or seven inches long, though, by
+    reason it had four Drawers, it could very much be lengthened, as
+    occasion required; this was contriv'd with three Glasses; a small
+    Object Glass at A, a thinner Eye Glass about B, and a very deep one
+    about C: this I made use of only when I had occasion to see much of an
+    Object at once; the middle Glass conveying a very great company of
+    radiating Pencils, which would go another way, and throwing them upon
+    the deep Eye Glass. But when ever I had occasion to examine the small
+    parts of a Body more accurately, I took out the middle Glass, and only
+    made use of one Eye Glass with the Object Glass, for always the fewer
+    the Refractions are, the more bright and clear the Object appears. And
+    therefore 'tis not to be doubted, but could we make a_ Microscope _to
+    have one only refraction, it would, _caeteris paribus_, far excel any
+    other that had a greater number. And hence it is, that if you take a
+    very clear piece of a broken _Venice_ Glass, and in a Lamp draw it out
+    into very small hairs or threads, then holding the ends of these
+    threads in the flame, till they melt and run into a small round Globul,
+    or drop, which will hang at the end of the thread; and if further you
+    stick several of these upon the end of a stick with a little sealing
+    Wax, so as that the threads stand upwards, and then on a Whetstone
+    first grind off a good part of them, and afterward on a smooth Metal
+    plate, with a little Tripoly, rub them till they come to be very
+    smooth; if one of these be fixt with a little soft Wax against a small
+    needle hole, prick'd through a thin Plate of Brass, Lead, Pewter, or
+    any other Metal, and an Object, plac'd very near, be look'd at through
+    it, it will both magnifie and make some Objects more distinct then any
+    of the great _Microscopes_. But because these, though exceeding easily
+    made, are yet very troublesome to be us'd, because of their smallness,
+    and the nearness of the Object; therefore to prevent both these, and
+    yet have only two Refractions, I provided me a Tube of Brass, shap'd
+    much like that in the fourth Figure of the first _Scheme_; into the
+    smaller end of this I fixt with Wax a good _plano convex_ Object Glass,
+    with the convex side towards the Object, and into the bigger end I fixt
+    also with wax a pretty large plano _Convex_ Glass, with the _convex_
+    side towards my eye, then by means of the small hole by the side, I
+    fill'd the intermediate space between these two Glasses with very clear
+    Water, and with a Screw stopp'd it in; then putting on a Cell for the
+    Eye, I could perceive an Object more bright then I could when the
+    intermediate space was only fill'd with Air, but this, for other
+    inconveniences, I made but little use of.
+
+    My way for fixing both the Glass and Object to the Pedestal most
+    conveniently was thus: Upon one side of a round Pedestal AB, in the
+    sixth Figure of the first _Scheme_, was fixt a small Pillar CC, on this
+    was fitted a small Iron Arm D, which could be mov'd up and down, and
+    fixt in any part of the Pillar, by means of a small Screw E; on the end
+    of this Arm was a small Ball fitted into a kind of socket F, made in
+    the side of the Brass Ring G, through which the small end of the Tube
+    was screw'd; by means of which contrivance I could place and fix the
+    Tube in what posture I desir'd (which for many Observations was
+    exceeding necessary) and adjusten it most exactly to any Object.
+
+    For placing the Object, I made this contrivance; upon the end of a
+    small brass Link or Staple HH, I so fastned a round Plate II, that it
+    might be turn'd round upon its Center K, and going pretty stiff, would
+    stand fixt in any posture it was set; on the side of this was fixt a
+    small Pillar P, about three quarters of an inch high, and through the
+    top of this was thrust a small Iron pin M, whose top just stood over
+    the Center of the Plate; on this top I fixt a small Object, and by
+    means of these contrivances I was able to turn it into all kind of
+    positions, both to my Eye and the Light; for by moving round the small
+    Plate on its center, could move it one way, and by turning the Pin M, I
+    could move it another way, and this without stirring the Glass at all,
+    or at least but very little; the Plate likewise I could move to and fro
+    to any part of the Pedestal (which in many cases was very convenient)
+    and fix it also in any Position, by means of a Nut N, which was screw'd
+    on upon the lower part of the Pillar CC. All the other Contrivances are
+    obvious enough from the draught, and will need no description.
+
+Now though this were the Instrument I made most use of, yet I have made
+several other Tryals with other kinds of Microscopes, which both for
+_matter_ and _form_ were very different from common spherical Glasses. I
+have made a _Microscope_ with one piece of Glass, both whose surfaces were
+_plains_. I have made another only with a _plano concave_, without any kind
+of reflection, divers also by means of _reflection_. I have made others of
+_Waters_, _Gums_, _Resins_, _Salts_, _Arsenick_, _Oyls_, and with divers
+other _mixtures of watery_ and _oyly Liquors_. And indeed the subject is
+capable of a great variety; but I find generally none more useful then that
+which is made with _two Glasses_, such as I have already describ'd.
+
+What the things are I observ'd, the following descriptions will manifest;
+in brief, they were either _exceeding small Bodies_, or _exceeding small
+Pores_, or _exceeding small Motions_, some of each of which the Reader will
+find in the following Notes, and such, as I presume, (many of them at
+least) will be _new_, and perhaps not less _strange_: Some _specimen_ of
+each of which Heads the Reader will find in the subsequent delineations,
+and indeed of some more then I was willing there should be; which was
+occasioned by my first Intentions to print a much greater number then I
+have since found time to compleat. Of such therefore as I had, I selected
+only some few of every Head, which for some particulars seem'd most
+observable, rejecting the rest as superfluous to the present Design.
+
+What each of the delineated Subjects are, the following descriptions
+annext to each will inform, of which I shall here, only once for all, add,
+That in divers of them the Gravers have pretty well follow'd my directions
+and draughts; and that in making of them, I indeavoured (as far as I was
+able) first to discover the true appearance, and next to make a plain
+representation of it. This I mention the rather, because of these kind of
+Objects there is much more difficulty to discover the true shape, then of
+those visible to the naked eye, the same Object seeming quite differing, in
+one position to the Light, from what it really is, and may be discover'd in
+another. And therefore I never began to make any draught before by many
+examinations in several lights, and in several positions to those lights, I
+had discover'd the true form. For it is exceeding difficult in some
+Objects, to distinguish between a _prominency_ and a _depression_, between
+a _shadow_ and a _black stain_, or a _reflection_ and a _whiteness in the
+colour_. Besides, the transparency of most Objects renders them yet much
+more difficult then if they were _opacous_. The Eyes of a Fly in one kind
+of light appear almost like a Lattice, drill'd through with abundance of
+small holes; which probably may be the Reason, why the Ingenious _Dr.
+Power_ seems to suppose them such. In the Sunshine they look like a Surface
+cover'd with golden Nails; in another posture, like a Surface cover'd with
+Pyramids; in another with Cones; and in other postures of quite other
+shapes; but that which exhibits the best, is the Light collected on the
+Object, by those means I have already describ'd.
+
+And this was undertaken in prosecution of the Design which the _ROYAL
+SOCIETY_ has propos'd to it self. For the Members of the Assembly having
+before their eys so many _fatal_ Instances of the errors and falshoods, in
+which the greatest part of mankind has so long wandred, because they rely'd
+upon the strength of humane Reason alone, have begun anew to correct all
+_Hypotheses_ by sense, as Seamen do their _dead Reckonings_ by _Coelestial
+Observations_; and to this purpose it has been their principal indeavour to
+_enlarge & strengthen_ the _Senses_ by _Medicine_, and by such _outward
+Instruments_ as are proper for their particular works. By this means they
+find some reason to suspect, that those effects of Bodies, which have been
+commonly attributed to _Qualities_, and those confess'd to be _occult_, are
+perform'd by the small _Machines_ of Nature, which are not to be discern'd
+without these helps, seeming the meer products of _Motion_, _Figure_, and
+_Magnitude_; and that the _Natural Textures_, which some call the _Plastick
+faculty_, may be made in _Looms_, which a greater perfection of Opticks may
+make discernable by these Glasses; so as now they are no more puzzled about
+them, then the vulgar are to conceive, how _Tapestry_ or _flowred Stuffs_
+are woven. And the ends of all these Inquiries they intend to be the
+_Pleasure_ of Contemplative minds, but above all, the _ease and dispatch_
+of the labours of mens hands. They do indeed neglect no opportunity to
+bring all the _rare_ things of Remote Countries within the compass of their
+knowledge and practice. But they still acknowledg their _most useful_
+Informations to arise from _common_ things, and from _diversifying_ their
+most _ordinary_ operations upon them. They do not wholly reject Experiments
+of meer _light_ and _theory_; but they principally aim at such, whose
+Applications will _improve and facilitate_ the present way of _Manual
+Arts_. And though some men, who are perhaps taken up about less honourable
+Employments, are pleas'd to censure their proceedings, yet they can shew
+more _fruits_ of their first three years, wherein they have assembled, then
+any other _Society_ in _Europe_ can for a much larger space of time. 'Tis
+true, such undertakings as theirs do commonly meet with small
+incouragement, because men are generally rather taken with the _plausible_
+and _discursive_, then the _real_ and the solid part of Philosophy; yet by
+the good fortune of their institution, in an Age of all others the most
+_inquisitive_, they have been assisted by the _contribution_ and _presence_
+of very many of the chief _Nobility_ and _Gentry_, and others who are some
+of the _most considerable_ in their several Professions. But that that yet
+farther convinces me of the _Real esteem_ that the more _serious_ part of
+men have of this _Society_, is, that several _Merchants_, men who act in
+earnest (whose Object is _meum & tuum_, that great _Rudder_ of humane
+affairs) have adventur'd considerable sums of _Money_, to put in practice
+what some of our Members have contrived, and have continued _stedfast_ in
+their good opinions of such Indeavours, when not one of a hundred of the
+vulgar have believed their undertakings feasable. And it it also fit to be
+added, that they have one advantage peculiar to themselves, that very many
+of their number are _men of Converse and Traffick_; which is a good Omen,
+that their attempts will bring Philosophy from _words_ to _action_, seeing
+the men of Business have had so great a share in their first foundation.
+
+And of this kind I ought not to conceal one particular _Generosity_, which
+more nearly concerns my self. It is the _munificence_ of _Sir John Cutler_,
+in endowing a Lecture for the promotion of _Mechanick Arts_, to be governed
+and directed by This _Society._This _Bounty_ I mention for the
+_Honourableness_ of the thing it self, and for the expectation which I have
+of the _efficacy_ of the _Example_; for it cannot now be objected to them,
+that their Designs will be esteemed _frivolous_ and _vain_, when they have
+such a _real Testimony_ of the _Approbation_ of a _Man_ that is such an
+_eminent Ornament_ of this renowned City, and one, who, by the _Variety_,
+and the _happy Success_, of his negotiations, has given evident proofs,
+that he is not easie to be deceiv'd. This Gentleman has well observ'd, that
+the _Arts_ of life have been too long _imprison'd_ in the dark shops of
+Mechanicks themselves, & there _hindred from growth_, either by ignorance,
+or self-interest: and he has bravely _freed_ them from these
+_inconveniences_: He hath not only obliged _Tradesmen_, but _Trade_ it
+self: He has done a work that is worthy of _London_, and has taught the
+chief City of Commerce in the world the right way how Commerce is to be
+improv'd. We have already seen many other great signs of Liberality and a
+large mind, from the same hand: For by his _diligence_ about the
+_Corporation for the Poor_; by his honorable _Subscriptions_ for the
+rebuilding of St. Paul's; by his chearful _Disbursment_ for the replanting
+of _Ireland_, and by many other such _publick works_, he has shewn by what
+means he indeavours to _establish_ his Memory; and now by this last gift he
+has done that, which became one of the _wisest Citizens_ of our Nation to
+accomplish, seeing one of the _wisest of our Statesmen, the Lord Verulam_,
+first propounded it.
+
+But to return to my Subject, from a digression, which, I hope, my Reader
+will pardon me, seeing the Example is so rare that I can make no more such
+digressions. If these my first Labours shall be any wayes useful to
+inquiring men, I must attribute the incouragement and promotion of them to
+a very _Reverend_ and _Learned Person_, of whom this ought in justice to be
+said, _That there is scarce any one Invention, which this Nation has
+produc'd in our Age, but it has some way or other been set forward by his
+assistance_. My Reader, I believe, will quickly ghess, that it is _Dr.
+Wilkins_ that I mean. He is indeed a man born for the _good_ of _mankind_,
+and for the _honour_ of his _Country_. In the _sweetness_ of whose
+_behaviour_, in the _calmness_ of his _mind_, in the _unbounded goodness_
+of his _heart_, we have an evident Instance, what the true and the
+_primitive unpassionate Religion_ was, before it was _sowred_ by particular
+_Factions._ In a word, his _Zeal_ has been so _constant_ and _effectual_ in
+advancing all good and profitable _Arts, that_ as one of the Antient
+_Romans_ said of _Scipio_, _That he thanked God that he was a _Roman_;
+because whereever _Scipio_ had been born, there had been the seat of the
+Empire of the world_: So may I thank God, that _Dr. Wilkins_ was an
+_Englishman_, for whereever he had lived, there had been the chief Seat of
+_generous Knowledge_ and _true Philosophy_. To the truth of this, there are
+so many worthy men living that will subscribe, that I am confident, what I
+have here said, will not be looked upon, by any ingenious Reader, as a
+_Panegyrick_, but only as a _real testimony_.
+
+By the Advice of this _Excellent man_ I first set upon this Enterprise,
+yet still came to it with much _Reluctancy_, because I was to follow the
+footsteps of so eminent a Person as _Dr. Wren_, who was the first that
+attempted any thing of this nature; whose original draughts do now make one
+of the Ornaments of that great Collection of Rarities in the _Kings
+Closet_. This _Honor_, which his first beginnings of this kind have
+receiv'd, to be admitted into the most famous place of the world, did not
+so much _incourage_, as the _hazard_ of coming after _Dr. Wren_ did
+_affright_ me; for of him I must, affirm, that, since the time of
+_Archimedes_, there scarce ever met in one man, in so great a perfection,
+such a _Mechanical Hand_, and so _Philosophical_ a _Mind_.
+
+But at last, being assured both by _Dr. Wilkins_, and _Dr. Wren_ himself,
+that he had given over his intentions of prosecuting it, and not finding
+that there was any else design'd the pursuing of it, I set upon this
+undertaking, and was not a little incourag'd to proceed in it, by the
+Honour the _Royal Society_ was pleas'd to favour me with, in approving of
+those draughts (which from time to time as I had an opportunity of
+describing) I presented to them. And particularly by the Incitements of
+divers of those Noble and excellent Persons of it, which were my more
+especial Friends, who were not less urgent with me for the publishing, then
+for the prosecution of them.
+
+After I had almost compleated these Pictures and Observations (having had
+divers of them ingraven, and was ready to send them to the Press) I was
+inform'd, that the Ingenious Physitian _Dr. Henry Power_ had made several
+_Microscopical_ Observations, which had I not afterwards, upon our
+interchangably viewing each others Papers, found that they were for the
+most part differing from mine, either in the Subject it self, or in the
+particulars taken notice of; and that his design was only to print
+Observations without Pictures, I had even then _suppressed_ what I had so
+far proceeded in. But being further _excited_ by several of my Friends, in
+complyance with their opinions, that it would not be unacceptable to
+several inquisitive Men, and hoping also, that I should thereby discover
+something New to the World, I have at length cast in my Mite, into the vast
+Treasury of _A Philosophical History_. And it is my _hope_, as well as
+_belief_, that these my _Labours_ will be no more comparable to the
+_Productions_ of many other _Natural Philosophers_, who are now every where
+busie about _greater_ things; then my _little Objects_ are to be compar'd
+to the greater and more beautiful _Works of Nature_, A Flea, a Mite, a
+Gnat, to an Horse, an Elephant, or a Lyon.
+
+
+       *       *       *       *       *
+
+
+MICROGRAPHIA,
+
+OR SOME
+
+Physiological Descriptions
+
+OF
+
+MINUTE BODIES,
+
+MADE BY
+
+MAGNIFYING GLASSES;
+
+WITH
+
+OBSERVATIONS and INQUIRIES thereupon.
+
+       *       *       *       *       *
+
+
+Observ. I. _Of the Point of a sharp small Needle._
+
+As in _Geometry_, the most natural way of beginning is from a Mathematical
+_point_; so is the same method in Observations and _Natural history_ the
+most genuine, simple, and instructive. We must first endevour to make
+_letters_, and draw _single_ strokes true, before we venture to write whole
+_Sentences_, or to draw large _Pictures_. And in _Physical_ Enquiries, we
+must endevour to follow Nature in the more _plain_ and _easie_ ways she
+treads in the most _simple_ and _uncompounded bodies_, to trace her steps,
+and be acquainted with her manner of walking there, before we venture our
+selves into the multitude of _meanders_ she has in _bodies of a more
+complicated_ nature; lest, being unable to distinguish and judge of our
+way, we quickly lose both _Nature_ our Guide, and _our selves_ too, and are
+left to wander in the _labyrinth_ of groundless opinions; wanting both
+_judgment_, that _light_, and _experience_, that _clew_, which should
+direct our proceedings.
+
+We will begin these our Inquiries therefore with the Observations of Bodies
+of the most _simple nature_ first, and so gradually proceed to those of a
+more _compounded_ one. In prosecution of which method, we shall begin with
+a _Physical point_; of which kind the _Point of a Needle_ is commonly
+reckon'd for one; and is indeed, for the most part, made so sharp, that the
+naked eye cannot distinguish any parts of it: It very easily pierces, and
+makes its way through all kind of bodies softer then it self: But if view'd
+with a very good _Microscope_, we may find that the _top_ of a Needle
+(though as to the sense very _sharp_) appears a _broad_, _blunt,_ and very
+_irregular_ end; not resembling a Cone, as is imagin'd, but onely a piece
+of a tapering body, with a great part of the top remov'd, or deficient. The
+Points of Pins are yet more blunt, and the Points of the most curious
+Mathematical Instruments do very seldome arrive at so great a sharpness;
+how much therefore can be built upon demonstrations made onely by the
+productions of the Ruler and Compasses, he will be better able to consider
+that shall but view those _points_ and _lines_ with a _Microscope_.
+
+Now though this point be commonly accounted the sharpest (whence when we
+would express the sharpness of a point the most _superlatively_, we say, As
+sharp as a Needle) yet the _Microscope_ can afford us hundreds of Instances
+of Points many thousand times sharper: such as those of the _hairs_, and
+_bristles_, and _claws_ of multitudes of _Insects_; the _thorns_, or
+_crooks_, or _hairs_ of _leaves_, and other small vegetables; nay, the ends
+of the _stiriae_ or small _parallelipipeds_ of _Amianthus_, and _alumen
+plumosum_; of many of which, though the Points are so sharp as not to be
+visible, though view'd with a _Microscope_ (which magnifies the Object, in
+bulk, above a million of times) yet I doubt not, but were we able
+_practically_ to make _Microscopes_ according to the _theory_ of them, we
+might find hills, and dales, and pores, and a sufficient bredth, or
+expansion, to give all those parts elbow-room, even in the blunt top of the
+very Point of any of these so very sharp bodies. For certainly the
+_quantity_ or extension of any body may be _Divisible in infinitum_, though
+perhaps not the _matter_.
+
+But to proceed: The Image we have here exhibited in the first Figure[1],
+was the top of a small and very sharp Needle, whose point _aa_ nevertheless
+appear'd through the _Microscope_ above a quarter of an inch broad, not
+round nor flat, but _irregular_ and _uneven_; so that it seem'd to have
+been big enough to have afforded a hundred armed Mites room enough to be
+rang'd by each other without endangering the breaking one anothers necks,
+by being thrust off on either side. The surface of which, though appearing
+to the naked eye very smooth, could not nevertheless hide a multitude of
+holes and scratches and ruggednesses from being discover'd by the
+_Microscope_ to invest it, several of which inequalities (as A, B, C,
+seem'd _holes_ made by some small specks of _Rust_; and D some
+_adventitious body_, that stuck very close to it) were _casual_. All the
+rest that roughen the surface, were onely so many marks of the rudeness and
+bungling of _Art_. So unaccurate is it, in all its productions, even in
+those which seem most neat, that if examin'd with an organ more acute then
+that by which they were made, the more we see of their _shape_, the less
+appearance will there be of their _beauty_: whereas in the works of
+_Nature_, the deepest Discoveries shew us the greatest Excellencies. An
+evident Argument, that he that was the Author of all these things, was no
+other then _Omnipotent_; being able to include as great a variety of parts
+and contrivances in the yet smallest Discernable Point, as in those vaster
+bodies (which comparatively are called also Points) such as the _Earth_,
+_Sun_, or _Planets_. Nor need it seem strange that the Earth it self may be
+by _Analogie_ call'd a Physical Point: For as its body, though now so near
+us as to fill our eys and fancies with a sense of the vastness of it, may
+by a little Distance, and some convenient _Diminishing_ Glasses, be made
+vanish into a scarce visible Speck, or Point (as I have often try'd on the
+_Moon_, and (when not too bright) on the _Sun_ it self.) So, could a
+Mechanical contrivance succesfully answer our _Theory_, we might see the
+least spot as big as the Earth it self; and Discover, as _Des Cartes_[2]
+also conjectures, as great a variety of bodies in the _Moon_, or _Planets_,
+as in the _Earth_.
+
+But leaving these Discoveries to future Industries, we shall proceed to add
+one Observation more of a _point_ commonly so call'd, that is, the mark of
+a _full stop_, or _period_. And for this purpose I observed many both
+_printed_ ones and _written_; and among multitudes I found _few_ of them
+more _round_ or _regular_ then this which I have delineated in the third
+figure of the second Scheme, but _very many_ abundantly _more disfigur'd_;
+and for the most part if they seem'd equally round to the eye, I found
+those points that had been made by a _Copper-plate,_ and Roll-press, to be
+as misshapen as those which had been made with _Types_, the most curious
+and smothly _engraven strokes_ and _points_, looking but as so many
+_furrows_ and _holes_, and their _printed impressions_, but like _smutty
+daubings_ on a matt or uneven floor with a blunt extinguisht brand or
+stick's end. And as for _points_ made with a _pen_ they were much _more
+ragged_ and _deformed_. Nay, having view'd certain pieces of exceeding
+curious writing of the kind (one of which in the bredth of a _two-pence_
+compris'd _the Lords prayer, the Apostles Creed, the ten Commandments, and
+about half a dozen verses besides of the Bible_, whose _lines_ were _so
+small_ and _near together_, that I was unable to _number_ them with my
+_naked eye_,) a very ordinary _Microscope_, I had then about me, inabled me
+to see that what the Writer of it had asserted was _true_, but withall
+discover'd of what pitifull _bungling scribbles_ and _scrawls_ it was
+compos'd, _Arabian_ and _China characters_ being almost as well shap'd, yet
+thus much I must say for the Man, that it was for the most part _legible_
+enough, though in some places there wanted a good _fantsy_ well _preposest_
+to help one through. If this manner _of small writing_ were made _easie_
+and _practicable_ (and I think I know such a one, but have never yet made
+tryal of it, whereby one might be inabled to write _a great deale_ with
+_much ease_, and _accurately_ enough in a very _little roome_) it might be
+of very good use to convey _secret Intelligence_ without any danger of
+_Discovery_ or _mistrusting_. But to come again to the point. The
+_Irregularities_ of it are caused by three or four _coadjutors_, one of
+which is, the _uneven surface_ of the _paper_, which at best appears no
+smother then a very course piece of _shag'd cloth_, next the _irregularity
+of the Type_ or _Ingraving_, and a third is the _rough Daubing_ of the
+_Printing-Ink_ that lies upon the instrument that makes the impression, to
+all which, add the _variation_ made by the Different _lights_ and
+_shadows_, and you may have sufficient reason to guess that a _point_ may
+appear much more _ugly_ then _this_, which I have here presented, which
+though it appear'd through the _Microscope_ _gray_, like a great splatch of
+_London_ dirt, about three inches over; yet to the _naked eye_ it was
+_black_ and no bigger then that in the midst of the Circle A. And could I
+have found Room in this Plate to have inserted an O you should have seen
+that the _letters_ were not more distinct then the _points_ of Distinction,
+nor a _drawn circle_ more exactly _so_, then we have now shown a _point_ to
+be a _point_.
+
+       *       *       *       *       *
+
+
+Observ. II. _Of the Edge of a Razor._
+
+The sharpest _Edge_ hath the same kind of affinity to the sharpest _Point_
+in Physicks, as a _line_ hath to a _point_ in Mathematicks; and therefore
+the Treaty concerning this, may very properly be annexed to the former. A
+Razor doth appear to be a Body of a very neat and curious aspect, till more
+closely viewed by the _Microscope_, and there we may observe its very Edge
+to be of all kind of shapes, except what it should be. For examining that
+of a very sharp one, I could not find that any part of it had any thing of
+sharpness in it; but it appeared a rough surface of a very considerable
+bredth from side to side, the narrowest part not seeming thinner then the
+back of a pretty thick Knife. Nor is't likely that it should appear any
+otherwise, since as we just now shew'd that a _point_ appear'd a _circle_,
+'tis rational a _line_ should be a _parallelogram_.
+
+Now for the drawing this second Figure[3] (which represents a part of the
+Edge about half a quarter of an inch long of a Razor well set) I so plac'd
+it between the Object-glass & the light, that there appear'd a reflection
+from the very Edge, represented by the white line abcdef. In which you may
+perceive it to be somewhat sharper then elsewhere about d, to be indented
+or pitted about b, to be broader and thicker about c, and unequal and
+rugged about e, and pretty even between ab and ef. Nor was that part of the
+Edge ghik so smooth as one would imagine so smooth bodies as a Hone and Oyl
+should leave it; for besides those multitudes of scratches, which appear to
+have raz'd the surface ghik, and to cross each other every way which are
+not half of them exprest in the Figure, there were several great and deep
+scratches, or furrows, such as gh and ik, which made the surface yet more
+rugged, caus'd perhaps by some small Dust casually falling on the Hone, or
+some harder or more flinty part of the Hone it self. The other part of the
+Razor ll, which is polish'd on a grinding-stone, appear'd much rougher then
+the other, looking almost like a plow'd field, with many parallels, ridges,
+and furrows, and a cloddy, as 'twere, or an uneven surface: nor shall we
+wonder at the roughnesses of those surfaces, since even in the most curious
+wrought Glasses for _Microscopes_, and other Optical uses, I have, when the
+Sun has shone well on them, discover'd their surface to be variously raz'd
+or scratched, and to consist of an infinite of small broken surfaces, which
+reflect the light of very various and differing colours. And indeed it
+seems impossible by Art to cut the surface of any hard and brittle body
+smooth, since _Putte_, or even the most curious _Powder_ that can be made
+use of, to polish such a body, must consist of little hard rough particles,
+and each of them must cut its way, and consequently leave some kind of
+gutter or furrow behind it. And though Nature does seem to do it very
+readily in all kinds of fluid bodies, yet perhaps future observators may
+discover even these also rugged; it being very probable, as I elsewhere
+shew, that fluid bodies are made up of small solid particles variously and
+strongly mov'd, and may find reason to think there is scarce a surface _in
+rerum natura_ perfectly smooth. The black spot mn, I ghess to be some small
+speck of rust, for that I have oft observ'd to be the manner of the working
+of Corrosive Juyces. To conclude, this Edge and piece of a Razor, if it had
+been really such as it appear'd through the _Microscope_, would scarcely
+have serv'd to cleave wood, much less to have cut off the hair of beards,
+unless it were after the manner that _Lucian_ merrily relates _Charon_ to
+have made use of, when with a Carpenters Axe he chop'd off the beard of a
+sage Philosopher, whose gravity he very cautiously fear'd would indanger
+the oversetting of his Wherry.
+
+       *       *       *       *       *
+
+
+Observ. III. _Of fine Lawn, or Linnen Cloth._
+
+This is another product of Art, A piece of the finest Lawn I was able to
+get, so curious that the threads were scarce discernable by the naked eye,
+and yet through an ordinary _Microscope_ you may perceive[4] what a goodly
+piece of _coarse Matting_ it is; what proportionable cords each of its
+threads are, being not unlike, both in shape and size, the bigger and
+coarser kind of _single Rope-yarn_, wherewith they usually make _Cables_.
+That which makes the Lawn so transparent, is by the _Microscope_, nay by
+the naked eye, if attentively viewed, plainly enough evidenced to be the
+multitude of square holes which are left between the threads, appearing to
+have much more hole in respect of the intercurrent parts then is for the
+most part left in a _lattice-window_, which it does a little resemble,
+onely the crossing parts are round and not flat.
+
+These threads that compose this fine contexture, though they are as small
+as those that constitute the finer sorts of Silks, have notwithstanding
+nothing of their glossie, pleasant, and lively reflection. Nay, I have been
+informed both by the Inventor himself, and several other eye-witnesses,
+that though the flax, out of which it is made, has been (by a singular art,
+of that excellent Person, and Noble Vertuoso, M. _Charls Howard_, brother
+to the _Duke of Norfolk_) so curiously dress'd and prepar'd, as to appear
+both to the eye and the touch, full as _fine_ and as _glossie_, and to
+receive all kinds of colours, as well as Sleave-Silk; yet when this Silken
+Flax is twisted into threads, it quite loseth its former luster, and
+becomes as plain and base a thread to look on, as one of the same bigness,
+made of common Flax.
+
+The reason of which odd _Phenomenon_ seems no other then this; that though
+the curiously drest Flax has its parts so exceedingly small, as to
+equallize, if not to be much smaller then the clew of the Silk-worm,
+especially in thinness, yet the differences between the figures of the
+constituting filaments are so great, and their substances so various, that
+whereas those of the _Silk_ are _small_, _round_, _hard_, _transparent,_
+and to their bigness proportionably _stiff_, so as each filament preserves
+its proper _Figure_, and consequently its vivid _reflection_ intire, though
+twisted into a thread, if not too hard; those of Flax are _flat_, _limber_,
+_softer,_ and _less transparent_, and in twisting into a thread they joyn,
+and lie so close together, as to lose their own, and destroy each others
+particular reflections. There seems therefore three Particulars very
+requisite to make the so drest Flax appear Silk also when spun into
+threads. First, that the substance of it should be made more _clear_ and
+_transparent_, Flax retaining in it a kind of opacating brown, or yellow;
+and the parts of the whitest kind I have yet observ'd with the _Microscope_
+appearing white, like flaw'd Horn or Glass, rather then clear, like clear
+Horn or Glass. Next that, the filaments should each of them be _rounded_,
+if that could be done, which yet is not so very necessary, if the first be
+perform'd, and this third, which is, that each of the small filaments be
+_stifned_; for though they be square, or flat, provided they be
+_transparent_ and stiff, much the same appearances must necessarily follow.
+Now, though I have not yet made trial, yet I doubt not, but that both these
+proprieties may be also induc'd upon the Flax, and perhaps too by one and
+the same Expedient, which some trials may quickly inform any ingenious
+attempter of, who from the use and profit of such an Invention, may find
+sufficient argument to be prompted to such Inquiries. As for the _tenacity_
+of the substance of Flax, out of which the thread is made, it seems much
+inferiour to that of Silk, the one being a _vegetable_, the other an
+_animal_ substance. And whether it proceed from the better concoction, or
+the more homogeneous constitution of _animal_ substances above those of
+_vegetables_, I do not here determine; yet since I generally find, that
+_vegetable_ substances do not equalize the _tenacity_ of _animal_, nor
+these the _tenacity_ of some purified _mineral_ substances; I am very apt
+to think, that the _tenacity_ of bodies does not proceed from the _hamous_,
+or _hooked_ particles, as the _Epicureans_ and some modern _Philosophers_
+have imagin'd; but from the more exact _congruity_ of the constituent
+parts, which are contiguous to each other, and so bulky, as not to be
+easily separated, or shatter'd, by any small pulls or concussion of heat.
+
+       *       *       *       *       *
+
+
+Observ. IV. _Of fine waled Silk, or Taffety._
+
+This[5] is the appearance of a piece of very fine Taffety-riband in the
+bigger magnifying Glass, which you see exhibits it like a very convenient
+substance to make Bed-matts, or Door-matts of, or to serve for Beehives,
+Corn-scuttles, Chairs, or Corn-tubs, it being not unlike that kind of work,
+wherewith in many parts in _England_, they make such Utensils of Straw, a
+little wreathed, and bound together with thongs of Brambles. For in this
+Contexture, each little filament, fiber, or clew of the Silk-worm, seem'd
+about the bigness of an ordinary Straw, as appears by the little irregular
+pieces, ab, cd, and ef; The _Warp_, or the thread that ran crossing the
+Riband, appear'd like a single Rope of an Inch Diameter; but the _Woof_, or
+the thread that ran the length of the Riband, appear'd not half so big.
+Each Inch of six-peny-broad Riband appearing no less then a piece of
+Matting Inch and half thick, and twelve foot square, a few yards of this,
+would be enough to floor the long Gallery of the _Loure_ at _Paris_. But to
+return to our piece of Riband: It affords us a not unpleasant object,
+appearing like a bundle, or wreath, of very clear and transparent
+_Cylinders_, if the Silk be white, and curiously ting'd; if it be colour'd,
+each of those small horney _Cylinders_ affording in some place or other of
+them, as vivid a reflection, as if it had been sent from a _Cylinder_ of
+Glass or Horn. In-so-much, that the reflexions of Red, appear'd as if
+coming from so many _Granates_, or _Rubies_. The loveliness of the colours
+of Silks above those of hairy Stuffs, or Linnen, consisting, as I
+else-where intimate, chiefly in the transparency, and vivid reflections
+from the _Concave_, or inner surface of the _transparent Cylinder_, as are
+also the colours of Precious Stones; for most of the reflections from each
+of these _Cylinders_, come from the _Concave_ surface of the air, which is
+as 'twere the foil that incompasses the _Cylinder_. The colours with which
+each of these _Cylinders_ are ting'd, seem partly to be superficial, and
+sticking to the out-sides of them; and partly, to be imbib'd, or sunck into
+the substance of them: for Silk, seeming to be little else then a dried
+thread of Glew, may be suppos'd to be very easily relaxt, and softened, by
+being steeped in warm, nay in cold, if penetrant, juyces or liquors. And
+thereby those tinctures, though they tinge perhaps but a small part of the
+substance, yet being so highly impregnated with the colour, as to be almost
+black with it, may leave an impression strong enough to exhibite the
+desir'd colour. A pretty kinde of artificial Stuff I have seen, looking
+almost like transparent Parchment, Horn, or Ising-glass, and perhaps some
+such thing it may be made of, which being transparent, and of a glutinous
+nature, and easily mollified by keeping in water, as I found upon trial,
+had imbib'd, and did remain ting'd with a great variety of very vivid
+colours, and to the naked eye, it look'd very like the substance of the
+Silk. And I have often thought, that probably there might be a way found
+out, to make an artificial glutinous composition, much resembling, if not
+full as good, nay better, then that Excrement, or whatever other substance
+it be out of which, the Silk-worm wire-draws his clew. If such a
+composition were found, it were certainly an easie matter to find very
+quick ways of drawing it out into small wires for use. I need not mention
+the use of such an Invention, nor the benefit that is likely to accrue to
+the finder, they being sufficiently obvious. This hint therefore, may, I
+hope, give some Ingenious inquisitive Person an occasion of making some
+trials, which if successfull, I have my aim, and I suppose he will have no
+occasion to be displeas'd.
+
+       *       *       *       *       *
+
+
+Observ. V. _Of watered Silks, or Stuffs._
+
+There are but few _Artificial_ things that are worth observing with a
+_Microscope_, and therefore I shall speak but briefly concerning them. For
+the Productions of art are such rude mis-shapen things, that when view'd
+with a _Microscope_, is little else observable, but their deformity. The
+most curious Carvings appearing no better then those rude _Russian_ Images
+we find mention'd in _Purchas_, where three notches at the end of a Stick,
+stood for a face. And the most smooth and burnish'd surfaces appear most
+rough and unpolisht: So that my first Reason why I shall add but a few
+observations of them, is, their mis-shapen form; and the next, is their
+uselessness. For why should we trouble our selves in the examination of
+that form or shape (which is all we are able to reach with a _Microscope_)
+which we know was design'd for no higher a use, then what we were able to
+view with our naked eye? Why should we endeavour to discover mysteries in
+that which has no such thing in it? And like _Rabbins_ find out
+_Caballisms_, and _aenigmas_ in the Figure, and placing of Letters, where
+no such thing lies hid: whereas in _natural_ forms there are some so small,
+and so curious, and their design'd business so far remov'd beyond the reach
+of our sight, that the more we magnify the object, the more excellencies
+and mysteries do appear; And the more we discover the imperfections of our
+senses; and the Omnipotency and Infinite perfections of the great Creatour.
+I shall therefore onely add one or two Observations more _artificial_
+things, and then come to the Treaty concerning such matters as are the
+Productions of a more curious Workman. One of these, shall be that of a
+piece of water'd Silk, represented in the second Figure of the third
+_Scheme_,[6] as it appear'd through the least magnifying Glass. _AB_
+signifying the long way of the Stuff, and _CD_ the broad way. This Stuff,
+if the right side of it be looked upon, appears to the naked eye, all over
+so waved, undulated, or grain'd, with a curious, though irregular variety
+of brighter and darker parts, that it adds no small gracefulness to the
+Gloss of it. It is so known a propriety, that it needs but little
+explication, but it is observable, which perhaps everyone has not
+considered, that those parts which appear the darker part of the wave, in
+one position to the light, in another appears the lighter, and the
+contrary; and by this means the undulations become transient, and in a
+continual change, according as the position of the parts in respect of the
+incident beams of light is varied. The reason of which odd _phaenomena_, to
+one that has but diligently examin'd it even with his naked eye, will be
+obvious enough. But he that observes it with a _Microscope_, may more
+easily perceive what this _Proteus_ is, and how it comes to change its
+shape. He may very easily perceive, that it proceeds onely from the variety
+of the _Reflections_ of light, which is caus'd by the various _shape of the
+Particles_, or little protuberant parts of the thread that compose the
+surface; and that those parts of the waves that appear the brighter, throw
+towards the eye a multitude of small reflections of light, whereas the
+darker scarce afford any. The reason of which reflection, the _Microscope_
+plainly discovers, as appears by the Figure. In which you may perceive,
+that the brighter parts of the surface consist of an abundance of large and
+strong reflections, denoted by a, a, a, a, a, &c. for the surfaces of those
+threads that run the _long way_, are by the Mechanical process of watering,
+_creas'd_ or _angled_ in another kind of posture then they were by the
+weaving: for by the weaving they are onely _bent round_ the warping
+threads; but by the watering, they are _bent with an angle, or elbow_, that
+is in stead of lying, or being bent _round_ the threads, as in the third
+Figure, a, a, a, a, a, are about b, b, b (b, b, b representing the ends, as
+'twere, of the cross threads, they are bent about) they are creas'd on the
+top of those threads, with an _angle_, as in the fourth Figure, and that
+with all imaginable variety; so that, whereas before they reflected the
+light onely from one point of the round surface, as about c, c, c, they now
+when water'd, reflect the beams from more then half the whole surface, as
+de, de, de, and in other postures they return no reflections at all from
+those surfaces. Hence in one posture they compose the brighter parts of the
+waves, in another the darker. And these reflections are also varied,
+according as the particular parts are variously bent. The reason of which
+creasing we shall next examine; and here we must fetch our information from
+the Mechanism or manner of proceeding in this operation; which, as I have
+been inform'd, is no other then this.
+
+They double all the Stuff that is to be water'd, that is, they crease it
+just through the middle of it, the whole length of the piece, leaving the
+right side of the Stuff inward, and placing the two edges, or silvages just
+upon one another, and, as near as they can, place the wale so in the
+doubling of it, that the wale of the one side may lie very near parallel,
+or even with the wale of the other; for the nearer that posture they lie,
+the greater will the watering appear; and the more obliquely, or across to
+each other they lie, the smaller are the waves. Their way for folding it
+for a great wale is thus: they take a Pin, and begin at one side of the
+piece in any wale, and so moving it towards the other side, thereby direct
+their hands to the opposite ends of the wale, and then, as near as they
+can, place the two opposite ends of the same wale together, and so double,
+or fold the whole piece, repeating this enquiry with a Pin at every yard or
+two's distance through the whole length; then they sprinkle it with water,
+and fold it the longways, placing between every fold a piece of Pastboard,
+by which means all the wrong side of the water'd Stuff becomes flat, and
+with little wales, and the wales on the other side become the more
+protuberant; whence the creasings or angular bendings of the wales become
+the more perspicuous. Having folded it in this manner, they place it with
+an interjacent Pastboard into an hot Press, where it is kept very violently
+prest, till it be dry and stiff; by which means, the wales of either
+contiguous sides leave their own impressions upon each other, as is very
+manifest by the second Figure, where 'tis obvious enough, that the wale of
+the piece ABCD runs parallel between the pricked lines ef, ef, ef, and as
+manifest to discern the impressions upon these wales, left by those that
+were prest upon them, which lying not exactly parallel with them, but a
+little athwart them, as is denoted by the lines of, oooo, gh, gh, gh,
+between which the other wales did lie parallel; they are so variously, and
+irregularly creas'd that being put into that shape when wet, and kept so
+till they be drie, they so let each others threads, that the Moldings
+remain almost as long as the Stuff lasts.
+
+Hence it may appear to any one that attentively considers the Figure, why
+the parts of the wale a, a, a, a, a, a, should appear bright; and why the
+parts b, b, b, b, b, b, b, should appear shadowed, or dark; why some, as d,
+d, d, d, d, d, should appear partly light, and partly dark: the varieties
+of which reflections and shadows are the only cause of the appearance of
+watering in Silks, or any other kind of Stuffs.
+
+From the variety of reflection, may also be deduc'd the cause why a small
+breez or gale of wind ruffling the surface of a smooth water, makes it
+appear black; as also, on the other side, why the smoothing or burnishing
+the surface of whitened Silver makes it look black; and multitudes of other
+phaenomena might hereby be solv'd, which are too many to be here insisted
+on.
+
+       *       *       *       *       *
+
+
+Observ. VI. _Of Small Glass Canes._
+
+That I might be satisfied, whether it were not possible to make an
+_Artificial_ pore as _small_ as any _Natural_ I had yet found, I made
+several attemps with small _glass pipes_, melted in the flame of a Lamp,
+and then very _suddenly_ drawn out into a great length. And, by _that
+means_, without much difficulty, I was able to draw some almost as small as
+a _Cobweb_, which yet, with the _Microscope_, I could plainly perceive[7]
+to be _perforated_, both by looking on the _ends_ of it, and by looking on
+it _against the light_ which was much the _easier way_ to determine whether
+it were solid or perforated; for, taking a small pipe of glass, and closing
+one end of it, then filling it _half full_ of water, and holding it
+_against the light_, I could, by this means, very easily find what was the
+_differing aspect_ of a _solid_ and a _perforated_ piece of glass; and so
+easily distingish, without seeing either end, whether any _Cylinder_ of
+glass I look'd on, were a _solid stick_, or a _hollow cane_. And by this
+means, I could also presently judge of any small _filament_ of glass,
+whether it were _hollow_ or _not_, which would have been exceeding tedious
+to examine by looking on the end. And many such like ways I was fain to
+make use of, in the examining of divers other particulars related in this
+Book, which would have been no easie task to have determined meerly by the
+more common way of looking on, or viewing the Object. For, if we consider
+first, the very _faint light_ wherewith the object is enlightened, whence
+many particles appear _opacous_, which when more enlightned, appear very
+_transparent_, so that I was fain to _determine_ its _transparency_ by one
+glass, and its _texture_ by another. Next, the _unmanageableness_ of most
+_Objects_, by reason of their _smalness_, 3. The _difficulty of finding_
+the desired point, and of _placing_ it so, as to reflect the _light
+conveniently_ for the Inquiry. Lastly, ones being able to view it but with
+_one eye_ at once, they will appear no small _obstructions_, nor are they
+easily _remov'd_ without many _contrivances_. But to proceed, I could not
+find that water, or some _deeply ting'd_ liquors would in small ones rise
+so high as one would expect; and the _highest_ I have found it yet rise in
+any of the pipes I have try'd, was to 21 _inches_ above the level of the
+water in the vessel: for though I found that in the small pipes it would
+_nimbly enter_ at first, and run about 6 or 7 _inches_ upwards; yet I found
+it then to move upwards _so slow_, that I have not yet had the _patience_
+to observe it above that height of 21 _inches_ (and that was in a pretty
+_large Pipe_, in comparison of those I formerly mentioned; for I could
+observe the _progress_ of a _very deep ting'd liquor_ in it with my _naked
+eye_, without much trouble; whereas many of the _other pipes_ were so _very
+small_, that unless in a _convenient posture_ to the light, I could not
+perceive _them_:) But 'tis very probable, that a greater _patience_ and
+_assiduity_ may discover the liquors to _rise_, at least to remain
+_suspended_, at heights that I should be loath now even to _ghess_ at, if
+at least there be any _proportion_ kept between the height of the ascending
+liquor, and the _bigness of the holes_ of the pipes.
+
+_AN ATTEMPT FOR THE EXPLICATION OF THIS EXPERIMENT._
+
+My Conjecture, _That the unequal height of the surfaces of the water,
+proceeded from the greater pressure made upon the water by the Air without
+the Pipes_ ABC, _then by that within them_[8]; I shall endeavour to confirm
+from the truth of the two following _Propositions_:
+
+The first of which is, _That an unequal pressure of the incumbent Air, will
+cause an unequal height in the water's Surfaces_.
+
+And the second is, _That in this experiment there is such an unequal
+pressure_.
+
+That the first is true, the following _Experiment_ will evince. For if you
+take any Vessel so contrived, as that you can at pleasure either _increase_
+or _diminish_ the _pressure_ of the Air upon this or that part of the
+_Superficies_ of the _water_, the _equality_ of the height of those parts
+will presently be _lost_; and that part of the _Superficies_ that sustains
+the _greater pressure_, will be _inferior_ to that which undergoes the
+_less_. A fit Vessel for this purpose, will be an inverted Glass _Syphon_,
+such an one as is described in the _Sixth Figure_. For if into it you put
+Water enough to fill it as high as _AB_, and gently blow in at _D_, you
+shall _depress_ the Superficies _B_, and thereby _raise_ the opposite
+Superficies _A_ to a _considerable height_, and by gently _sucking_ you may
+produce clean _contrary_ effects.
+
+Next, That there is such an _unequal pressure_, I shall prove from this,
+_That there is a much greater incongruity of Air to Glass, and some other
+Bodies, then there is of Water to the same_.
+
+By _Congruity, I mean a property of a fluid Body, whereby any part of it is
+readily united with any other part, either of itself, or of any other
+Similar, fluid, or solid body: And by Incongruity a property of a fluid, by
+which it is hindred from uniting with any dissimilar, fluid, or solid
+Body._
+
+This last property, any one that hath been observingly conversant about
+fluid Bodies, cannot be ignorant of. For (not now to mention several
+_Chymical Spirits_ and _Oyls_, which will _very hardly_, if at _all_, be
+brought to _mix_ with one another; insomuch that there may be found some 8
+or 9, or more, several distinct Liquors, which _swimming_ one upon another,
+will not presently _mix_) we need seek no further for Examples of this kind
+in _fluids_, then to observe the _drops of rain_ falling through the _air_
+and the _bubbles of air_ which are by any means conveyed under the surface
+of the _water_; or a drop of common _Sallet Oyl_ swimming upon water. In
+all which, and many more examples of this kind that might be enumerated,
+the _incongruity_ of two _fluids_ is easily discernable. And as for the
+_Congruity_ or _Incongruity_ of Liquids, with several kinds of _firm_
+Bodies, they have long since been taken notice of, and called by the Names
+of _Driness_ and _Moisture_ (though these two names are not comprehensive
+enough, being commonly used to signifie only the adhering or not adhering
+of _water_ to some other _solid Bodies_) of this kind we may observe that
+_water_ will more readily _wet some woods_ then _others_; and that _water_,
+let fall upon a _Feather_, the whiter side of a _Colwort_, and some other
+leaves, or upon almost any _dusty_, _unctuous_, or _resinous_ superficies,
+will not _at all adhere_ to them, but easily _tumble off_ from them, like a
+solid _Bowl_; whereas, if dropt upon _Linnen_, _Paper_, _Clay_, _green
+Wood_, &c. it will not be taken off, without leaving some part of it behind
+_adhering_ to them. So _Quick-silver_, which will very _hardly_ be brought
+to _stick_ to any _vegetable body_, will _readily adhere_ to, and _mingle_
+with, several clean _metalline bodies_.
+
+And that we may the better finde what the _cause_ of _Congruity_ and
+_Incongruity_ in bodies is, it will be requisite to consider, First, what
+is the _cause_ of _fluidness_; And this, _I conceive_, to be nothing else
+but a certain _pulse_ or _shake_ of _heat_; for Heat being nothing else but
+a very _brisk_ and _vehement agitation_ of the parts of a body (as I have
+elswhere made _probable_) the parts of a body are thereby made so _loose_
+from one another, that they easily _move any way_, and become _fluid_. That
+I may explain this a little by a gross Similitude, let us suppose a dish of
+sand set upon some body that is very much _agitated_, and shaken with some
+_quick_ and _strong vibrating motion_, as on a _Milstone_ turn'd round upon
+the under stone very violently whilst it is empty; or on a very stiff
+_Drum_-head, which is vehemently or very nimbly beaten with the Drumsticks.
+By this means, the sand in the dish, which before lay like a _dull_ and
+unactive body, becomes a perfect _fluid_; and ye can no sooner make a
+_hole_ in it with your finger, but it is immediately _filled up again_, and
+the upper surface of it _levell'd_. Nor can you _bury_ a _light body_, as a
+piece of Cork under it, but it presently _emerges_ or _swims_ as 'twere on
+the top; nor can you lay a _heavier_ on the top of it, as a piece of Lead,
+but it is immediately _buried_ in Sand, and (as 'twere) sinks to the
+bottom. Nor can you make a _hole_ in the side of the Dish, but the sand
+shall _run out_ of it to a _level_, not an _obvious property_ of a fluid
+body, as such, but this dos _imitate_; and all this meerly caused by the
+vehement _agitation_ of the conteining vessel; for by this means, _each_
+sand becomes to have a _vibrative_ or _dancing_ motion, so as no other
+heavier body can _rest_ on it, unless _sustein'd_ by some other on either
+side: Nor will it suffer any Body to be _beneath_ it, unless it be a
+_heavier_ then it self. Another Instance of the strange _loosening_ nature
+of a violent jarring Motion, or a strong and nimble vibrative one, we may
+have from a piece of _iron_ grated on very strongly with a _file_: for if
+into that a pin _screw'd_ so firm and hard, that though it has a convenient
+head to it, yet it can by no means be _unscrew'd_ by the fingers; if, I
+say, you attempt to unscrew this whilst _grated on by the file_, it will be
+found to undoe and turn very _easily_. The first of these Examples
+manifests, how a body actually _divided_ into small parts, becomes a
+_fluid_. And the latter manifests by what means the agitation of heat so
+easily _loosens_ and _unties_ the parts of _solid_ and _firm_ bodies. Nor
+need we suppose heat to be any thing else, besides such a motion; for
+supposing we could _Mechanically_ produce such a one _quick_ and _strong_
+enough, we need not spend _fuel_ to _melt_ a body. Now, that I do not speak
+this altogether groundless, I must refer the Reader to the Observations I
+have made upon the shining sparks of Steel, for there he shall find that
+_the same_ effects are produced upon small chips or parcels of Steel by the
+_flame_, and by _a quick and violent motion_; and if the body of _steel_
+may be thus melted (as I there shew it may) I think we have little reason
+to doubt that almost _any other_ may not also. Every Smith can inform one
+how quickly both his _File_ and the _Iron_ grows _hot_ with _filing_, and
+if you _rub_ almost any two _hard_ bodies together, they will do the same:
+And we know, that a sufficient degree of heat causes _fluidity_, in some
+bodies much sooner, and in others later; that is, the parts of the body of
+some are so _loose_ from one another, and so _unapt to cohere_, and so
+_minute_ and _little_, that a very _small_ degree of agitation keeps them
+always in the _state of fluidity_. Of this kind, I suppose, the _AEther_,
+that is the _medium_ or _fluid_ body, in which all other bodies do as it
+were swim and move; and particularly, the _Air_, which seems nothing else
+but a kind of _tincture_ or _solution_ of terrestrial and aqueous particles
+_dissolv'd_ into it, and agitated by it, just as the _tincture_ of
+_Cocheneel_ is nothing but some finer _dissoluble_ parts of that Concrete
+lick'd up or _dissolv'd_ by the _fluid_ water. And from this Notion of it,
+we may easily give a more Intelligible reason how the Air becomes so
+capable of _Rarefaction_ and _Condensation_. For, as in _tinctures_, one
+grain of some _strongly tinging_ substance may _sensibly_ colour some
+_hundred thousand_ grains of _appropriated_ Liquors, so as every _drop_ of
+it has its proportionate share, and be sensibly ting'd, as I have try'd
+both with _Logwood_ and _Cocheneel_: And as some few grains of _Salt_ is
+able to infect as great a quantity, as may be found by _praecipitations_,
+though not so easily by the _sight_ or _taste_; so the _Air_, which seems
+to be but as 'twere a _tincture_ or _saline substance, dissolv'd and
+agitated by the fluid and agil AEther_, may disperse and _expand_ it self
+into a _vast space_, if it have room enough, and infect, as it were, every
+part of that space. But, as on the other side, if there be but some _few
+grains_ of the liquor, it may _extract all_ the colour of the tinging
+substance, and may _dissolve_ all the Salt, and thereby become _much more
+impregnated_ with those substances, so may _all_ the air that sufficed in a
+_rarfy'd state_ to fill some _hundred thousand_ spaces of AEther, be
+compris'd in only _one_, but in a position proportionable _dense_. And
+though we have not yet found out such _strainers_ for Tinctures and Salts
+as we have for the Air, being yet unable to _separate_ them from their
+dissolving liquors by any kind of _filtre_, without _praecipitation_, as we
+are able to _separate_ the Air from the AEther by _Glass_, and several
+other bodies. And though we are yet unable and ignorant of the ways of
+_praecipitating_ Air out of the AEther as we can Tinctures, and Salts out
+of several _dissolvents_; yet neither of these seeming _impossible_ from
+the nature of the things, nor so _improbable_ but that some happy future
+industry may find out ways to effect them; nay, further, since we find that
+Nature _does really perform_ (though by what means we are not certain) both
+these actions, namely, by _praecipitating_ the Air in Rain and Dews, and by
+supplying the Streams and Rivers of the World with fresh water, _strain'd_
+through secret subterraneous Caverns: And since, that in very many other
+_proprieties_ they do so exactly _seem_ of the _same nature_; till further
+observations or tryals do inform us of the _contrary_, we may _safely
+enough conclude_ them of the _same kind_. For it seldom happens that any
+two natures have so many properties _coincident_ or the _same_, as I have
+observ'd Solutions and Air to have, and to be _different_ in the rest. And
+therefore I think it neither _impossible_, _irrational_, nay nor
+_difficult_ to be able to _predict_ what is _likely_ to happen in other
+particulars also, besides those which _Observation_ or _Experiment_ have
+declared thus or thus; especially, if the _circumstances_ that do often
+very much conduce to the variation of the effects be duly _weigh'd_ and
+_consider'd_. And indeed, were there not a _probability_ of this, our
+_inquiries_ would be _endless_, our _tryals vain_, and our greatest
+_inventions_ would be nothing but the meer _products_ of _chance_, and not
+of _Reason_; and, like _Mariners_ in an Ocean, destitute both of a
+_Compass_ and the sight of the _Celestial guids_, we might indeed, _by
+chance_, Steer _directly_ towards our desired Port, but 'tis _a thousand to
+one_ but we _miss_ our aim. But to proceed, we may hence also give a plain
+reason, how the Air comes to be _darkned_ by _clouds_, &c. which are
+nothing but a kind of _precipitation_, and how those _precipitations_ fall
+down in _Showrs_. Hence also could I very easily, and I think truly, deduce
+the cause of the curious _sixangular figures_ of Snow, and the appearances
+of _Haloes, &c._ and the sudden _thickning_ of the Sky with Clouds, and the
+_vanishing_ and _disappearing_ of those Clouds again; for all these things
+may be very easily _imitated_ in a _glass of liquor_, with some slight
+_Chymical preparations_ as I have often try'd, and may somewhere else more
+largely relate, but have not now time to set them down. But to proceed,
+there are other bodies that consist of particles more _Gross_, and of a
+more _apt_ figure for _cohesion_, and this requires _somewhat greater_
+agitation; such, I suppose [Mercury], _fermented vinous_ _Spirits_, several
+_Chymical Oils_, which are much of kin to those Spirits, &c. Others yet
+require a _greater_, as _water_, and so others _much greater_, for almost
+infinite degrees: For, I suppose there are very _few_ bodies in the world
+that may not be made _aliquatenus_ fluid, by _some_ or _other_ degree of
+agitation or heat.
+
+Having therefore in short set down my Notion of a Fluid body, I come in the
+next place to consider what _Congruity_ is; and this, as I said before,
+being a _Relative property_ of a fluid, whereby it may be said to be _like_
+or _unlike_ to this or that other body, whereby it _does_ or _does not mix_
+with this or that body. We will again have recourse to our former
+Experiment, though but a rude one; and here if we mix in the dish _several
+kinds_ of sands, some of _bigger_, others of _less_ and finer bulks, we
+shall find that by the agitation _the fine sand_ will _eject_ and _throw
+out_ of it self all those _bigger_ bulks of small _stones_ and the like,
+and those will _be gathered_ together all into _one_ place; and if there be
+_other_ bodies in it of other natures, those also will be _separated_ into
+a place by themselves, and _united_ or _tumbled_ up together. And though
+this do not come up to the _highest property_ of _Congruity_, which is a
+_Cohaesion_ of the parts of the fluid together, or a kind of _attraction_
+and _tenacity_, yet this does as 'twere _shadow_ it out, and somewhat
+resemble it; for just after the same manner, I suppose the _pulse_ of heat
+to _agitate_ the small parcels of matter, and those that are of a _like
+bigness_, and _figure_, and _matter_, will _hold_, or _dance_ together, and
+those which are of a _differing_ kind will be _thrust_ or _shov'd_ out from
+between them; for particles that are _similar_, will, like so many _equal
+musical strings equally stretcht_, vibrate together in a kind of _Harmony_
+or _unison_; whereas others that are _dissimilar_, upon what account
+soever, unless the disproportion be otherwise counter-ballanc'd, will, like
+so many _strings out of tune_ to those unisons, though they have the same
+agitating _pulse_, yet make quite _differing_ kinds of _vibrations_ and
+_repercussions_, so that though they may be both mov'd, yet are their
+_vibrations_ so _different_, and so _untun'd_, as 'twere to each other,
+that they _cross_ and _jar_ against each other, and consequently, _cannot
+agree_ together, but _fly back_ from each other to their similar particles.
+Now, to give you an instance how the _disproportion_ of some bodies in one
+respect, may be _counter-ballanc'd_ by a _contrary disproportion_ of the
+same body in another respect, whence we find that the subtil _vinous
+spirit_ is _congruous_, or does readily _mix_ with _water_, which in many
+properties is of a very _differing nature_, we may consider that a _unison_
+may be made either by two _strings_ of the same _bigness_, _length_, and
+_tension_, or by two strings of the same _bigness_, but of _differing
+length_, and a _contrary differing tension_, or _3ly._ by two strings of
+_unequal length_ and _bigness_, and of a _differing tension_, or of _equal
+length_, and _differing bigness_ and _tension_, and several other such
+varieties. To which _three properties_ in _strings_, will correspond _three
+proprieties_ also in _sand_, or the _particles_ of bodies, their _Matter_
+or _Substance_, their _Figure_ or _Shape_, and their _Body_ or _Bulk_. And
+from the _varieties_ of these _three_, may arise _infinite varieties_ in
+fluid bodies, though all agitated by the _same pulse_ or _vibrative_
+motion. And there may be as many ways of making Harmonies and Discords with
+these, as there may be with _musical strings_. Having therefore seen what
+is the cause of Congruity or Incongruity, those relative properties of
+fluids, we may, from what has been said, very easily collect, what is the
+_reason_ of those Relative proprieties also between _fluid bodies_ and
+_solid_; for since all bodies consist of _particles_ of such a _Substance_,
+_Figure_, and _Bulk_; but in some they are _united_ together more _firmly_
+then to be _loosened_ from each other by every _vibrative_ motion (though I
+imagine that there is no body in the world, but that some degree of
+agitation may, as I hinted before, agitate and loosen the particles so as
+to make them fluid) those _cohering_ particles may _vibrate_ in the same
+manner almost as those that are _loose_ and become _unisons_ or _discords_,
+as I may so speak, to them. Now that the _parts_ of all _bodies_, though
+never so _solid_, do yet _vibrate_, I think we need go no further for
+proof, then that _all_ bodies have some _degrees_ of _heat_ in them, and
+that there has not been yet found any thing _perfectly cold_: Nor can I
+believe indeed that there is any such thing in Nature, as a body whose
+particles are at _rest_, or _lazy_ and _unactive_ in the great _Theatre_ of
+the _World_, it being quite _contrary_ to the grand _Oeconomy_ of the
+Universe. We see therefore what is the reason of the _sympathy_ or uniting
+of some bodies together, and of the _antipathy_ or flight of others from
+each other: For _Congruity_ seems nothing else but a _Sympathy_, and
+_Incongruity_ an _Antipathy_ of bodies, hence _similar_ bodies once
+_united_ will not _easily part_, and _dissimilar_ bodies once _disjoyn'd_
+will not _easily unite_ again; from hence may be very easily deduc'd the
+reason of the _suspension_ of _water_ and _Quick-silver_ above their usual
+_station_, as I shall more at large anon shew.
+
+These properties therefore (alwayes the concomitants of fluid bodies)
+produce these following visible _Effects_:
+
+First, They _unite_ the parts of a fluid to its _similar_ Solid, or keep
+them _separate_ from its _dissimilar_. Hence _Quick-silver_ will (as we
+noted before) _stick_ to _Gold_, _Silver_, _Tin_, _Lead_, &c. and _unite_
+with them: but _roul_ off from _Wood_, _Stone_, _Glass_, &c. if never so
+little scituated out of its _horizontal level_; and _water_ that will _wet
+salt_ and _dissolve_ it, will _slip_ off from _Tallow_, or the like,
+without at all _adhering_; as it may likewise be observed to do upon a
+_dusty_ superficies. And next they cause the parts of _homogeneal fluid_
+bodies readily to _adhere_ together and _mix_, and of _heterogeneal_, to be
+exceeding _averse_ thereunto. Hence we find, that _two_ small _drops_ of
+_water_, on any superficies they can roul on, will, if they chance to touch
+each other, _readily unite_ and _mix_ into one 3d _drop_: The like may be
+observed with two small _Bowls_ of _Quick-silver_ upon a Table or Glass,
+provided their surfaces be not _dusty_; and with two drops of _Oyl_ upon
+fair water, _&c_. And further, _water_ put unto _wine_, _salt water_,
+_vinegar_, _spirit_ of _wine_, or the like, does immediately (especially if
+they be shaken together) _disperse_ it self all over them. Hence, on the
+contrary, we also find, that _Oyl of Tartar_ poured upon _Quick-silver,_
+and _Spirit of Wine_ on that _Oyl_, and _Oyl of Turpentine_ on that
+_Spirit_, and _Air_ upon that _Oyl_, though they be stopt closely up into a
+Bottle, and _shaken_ never so much, they will by no means long suffer any
+of their bigger parts to be _united_ or included within any of the other
+Liquors (by which recited Liquors, may be plainly enough represented the
+four _Peripatetical Elements_, and the more subtil _AEther_ above all.)
+From this property 'tis, that a drop of _water_ does not mingle with, or
+vanish into _Air_, but is _driven_ (by that Fluid equally protruding it on
+every side) and forc't into as little a space as it can possibly be
+contained in, namely, into a _Round Globule_. So likewise a little _Air_
+blown under the _water_, is _united_ or thrust into a _Bubble_ by the
+ambient water. And a parcel of _Quick-silver_ enclosed with _Air_, _Water_,
+or almost any other _Liquor_, is _formed_ into a _round Ball_.
+
+Now the cause why all these included Fluids, newly mentioned, or as many
+others as are wholly included within a heterogeneous fluid, are not
+_exactly_ of a _Spherical Figure_ (seeing that if caused by these
+Principles only, it could be of no other) must proceed from some other kind
+of _pressure_ against the two opposite flatted sides. This _adventitious_
+or _accidental pressure_ may proceed from _divers causes_, and accordingly
+must _diversifie_ the Figure of the included heterogeneous fluid: For
+seeing that a body may be included either with a fluid only, or only with a
+solid, or partly with a fluid, and partly with a solid, or partly with one
+fluid, and partly with another; there will be found a very great variety of
+the terminating _surfaces_, much differing from a _Spherical_, according to
+the various resistance or pressure that belongs to each of these
+encompassing bodies.
+
+Which Properties may in general be deduced from two heads, _viz._ _Motion_,
+and _Rest_. For, either this Globular Figure is altered by a _natural
+Motion_, such as is _Gravity_, or a _violent_, such as is any _accidental
+motion_ of the fluids, as we see in the _wind_ ruffling up the water, and
+the _purlings_ of _Streams_, and _foaming_ of _Catarracts_, and the like.
+Or thirdly, By the _Rest_, _Firmness_ and _Stability_ of the ambient
+_Solid_. For if the including _Solid_ be of an _angular_ or any other
+_irregular_ Form, the included _fluid_ will be near of the _like_, as a
+Pint-_Pot_ full of _water_, or a _Bladder_ full of _Air_. And next, if the
+including or included fluid have a greater _gravity_ one than another, then
+will the _globular_ Form be deprest into an _Elliptico-spherical_: As if,
+for example, we suppose the Circle _ABCD_, in the _fourth Figure_, to
+represent a _drop of water_, _Quick-silver_, or the like, included with the
+_Air_ or the like, which supposing there were no _gravity_ at all in either
+of the _fluids_, or that the _contained_ and _containing_ were of the _same
+weight,_ would be _equally comprest_ into an exactly _spherical_ body (the
+ambient fluid _forcing equally_ against every side of it.) But supposing
+either a greater _gravity_ in the included, by reason whereof the parts of
+it being _prest_ from _A_ towards _B_, and thereby the whole put into
+_motion_, and that _motion_ being _hindred_ by the _resistance_ of the
+_subjacent_ parts of the ambient, the _globular_ Figure _ADBC_ will be
+_deprest_ into the _Elliptico-spherical_, _EGFH_. For the side _A_ is
+_detruded_ to _E_ by the _Gravity_, and _B_ to _F_ by the _resistance_ of
+the subjacent medium: and therefore _C_ must necessarily be thrust to _G_;
+and _D_ to _H_. Or else, supposing a greater _gravity_ in the _ambient_, by
+whose more then ordinary _pressure_ against the under side of the included
+globule; _B_ will be forced to _F_, and by its _resistance_ of the motion
+_upwards_, the side _A_ will be _deprest_ to _E_, and therefore _C_ being
+thrust to _G_ and _D_ to _H_; the _globular_ Figure by this means also will
+be made an _Elliptico-spherical_. Next if a fluid be included _partly_ with
+one, and _partly_ with another fluid, it will be found to be shaped
+_diversly_, according to the proportion of the _gravity_ and _incongruity_
+of the 3 _fluids_ one to another: As in the _second Figure_, let the upper
+_MMM_ be _Air_, the middle _LMNO_ be common _Oyl_, the lower _OOO_ be
+_Water_, the _Oyl_ will be form'd, not into a _spherical_ Figure, such as
+is represented by the _pricked Line_, but into such a Figure as LMNO, whose
+side LMN will be of a flatter _Elliptical_ Figure, by reason of the great
+disproportion between the _Gravity_ of _Oyl_ and _Air_, and the side LOM of
+a rounder, because of the smaller difference between the weight of _Oyl_
+and _Water_. Lastly, The _globular_ Figure will be changed, if the
+_ambient_ be partly _fluid_ and partly _solid_. And here the termination of
+the incompassed _fluid_ towards the incompassing is shap'd according to the
+proportion of the congruity or incongruity of the _fluids_ to the _solids_,
+and of the gravity and incongruity of the _fluids_ one to another. As
+suppose the subjacent _medium_ that hinders an included fluids descent, be
+a _solid_, as let KI, in the _fourth Figure_, represent the smooth
+superficies of a _Table_; EGFH, a parcel of _running Mercury_; the side GFH
+will be more flatted, according to the proportion of the incongruity of the
+_Mercury_ and _Air_ to the _Wood_, and of the _gravity_ of _Mercury_ and
+_Air_ one to another; The side GEH will likewise be a little more deprest
+by reason the subjacent parts are now at rest, which were before in motion.
+
+Or further in the _third figure_, let AILD represent an including _solid_
+medium of a cylindrical shape (as suppose a small _Glass Jar_) Let FGEMM
+represent a contain'd _fluid_, as water; this towards the bottom and sides,
+is figured according to the concavity of the _Glass_: But its upper
+_Surface_, (which by reason of its gravity, (not considering at all the Air
+above it, and so neither the congruity or incongruity of either of them to
+the Glass) should be terminated by part of a _Sphere_ whose diameter should
+be the same with that of the earth, which to our sense would appear a
+straight _Line_, as FGE, Or which by reason of its having a greater
+congruity to Glass than Air has, (not considering its Gravity) would be
+thrust into a _concave Sphere_, as CHB, whose diameter would be the same
+with that of the concavity of the Vessel:) Its upper Surface, I say, by
+reason of its having a greater gravity then the Air, and having likewise a
+greater congruity to Glass then the Air has, is terminated, by a _concave
+Elliptico-spherical Figure_, as CKB. For by its congruity it easily
+conforms it self, and adheres to the Glass, and constitutes as it were one
+containing body with it, and therefore should thrust the contained Air on
+that side it touches it, into a _spherical_ Figure, as BHC, but the motion
+of Gravity depressing a little the Corners B and C, reduces it into the
+aforesaid Figure CKB. Now that it is the greater congruity of one of the
+two _contiguous fluids_, then of the other, to the containing _solid_, that
+causes the separating surfaces to be thus or thus figured: And that it is
+not because this or that figurated surface is more proper, natural, or
+peculiar to one of these fluid bodies, then to the other, will appear from
+this; that the same _fluids_ will by being put into differing _solids_,
+change their _surfaces_. For the same water, which in a Glass or wooden
+Vessel will have a concave surface upwards, and will rise higher in a
+smaller then a greater Pipe, the same water, I say, in the same Pipes
+greased over or oyled, will produce quite contrary effects; for it will
+have a _protuberant_ and _convex_ surface upwards, and will not rise so
+high in small, as in bigger Pipes: Nay, in the very same solid Vessel, you
+may make the very same two contiguous _Liquids_ to alter their Surfaces;
+for taking a small Wine-glass, or such like Vessel, and pouring water
+gently into it, you shall perceive the _surface_ of the water all the way
+_concave_, till it rise even with the top, when you shall find it (if you
+gently and carefully pour in more) to grow very _protuberant_ and _convex_;
+the reason of which is plain, for that the _solid_ sides of the containing
+body are no longer extended, to which the water does more readily adhere
+then the air; but it is henceforth to be included with air, which would
+reduce it into a _hemisphere_, but by reason of its _gravity_, it is
+flatted into an _Oval_. _Quicksilver_ also which to _Glass_ is more
+incongruous then _Air_ (and thereby being put into a _Glass-pipe_, will not
+adhere to it, but by the more _congruous air_ will be forced to have a very
+_protuberant_ surface, and to rise higher in a greater then a lesser Pipe)
+this _Quicksilver_ to clean _Metal_, especially to _Gold_, _Silver_, _Tin_,
+_Lead_, &c. _Iron_ excepted, is more _congruous_ then _Air_, and will not
+only stick to it, but have a _concave_ Surface like _water_, and rise
+higher in a less, then in a greater Pipe.
+
+In all these Examples it is evident, that there is an _extraordinary_ and
+_adventitious force_, by which the _globular_ Figure of the contained
+_heterogeneous_ fluid is altered; neither can it be imagined, how it should
+otherwise be of any other Figure then _Globular_: For being by the
+_heterogeneous_ fluid equally _protruded_ every way, whatsoever part is
+_protuberant_, will be thereby _deprest_. From this cause it is, that in
+its effects it does very much resemble a _round Spring_ (such as a _Hoop_.)
+For as in a _round Spring_ there is required an additional _pressure_
+against two opposite sides, to reduce it into an _Oval_ Form, or to force
+it in between the sides of a _Hole,_ whose _Diameter_ is less then that of
+the _Spring_, there must be a considerable force or _protusion_ against
+_the concave_ or inner side of the _Spring_; So to alter this _spherical_
+constitution of an included fluid body, there is required more pressure
+against opposite sides to reduce it into an _Oval_; and, to press it into
+an _Hole_ less in _Diameter_ then it self, it requires a greater
+_protrusion_ against all the other sides, What degrees of force are
+requisite to reduce them into longer and longer _Ovals_, or to press them
+into less and less _holes_, I have not yet experimentally calculated; but
+thus much by experiment I find in general, that there is alwayes required a
+greater pressure to close them into longer _Ovals_, or protude them into
+smaller _holes_. The necessity and reason of this, were it requisite, I
+could easily explain: but being not so necessary, and requiring more room
+and time then I have for it at present, I shall here omit it; and proceed
+to shew, that this may be presently found true, if Experiment be made with
+a _round Spring_ (the way of making which trials is _obvious_ enough.) And
+with the fluid bodies of _Mercury_, _Air_, _&c_, the way of trying which,
+will be somewhat more difficult; and therefore I shall in brief describe
+it. He therefore that would try with _Air_, must first be provided of a
+_Glass-pipe_, made of the shape of that in the _fifth Figure_, whereof the
+side AB, represents a straight _Tube_ of about three foot long, C,
+represents another part of it, which consists of a _round Bubble_; so
+ordered, that there is left a _passage_ or _hole_ at the top, into which
+may be fastened with _cement_ several _small Pipes_ of determinate
+_cylindrical_ cavities: as let _hollow_ of
+
+  F.       1/4
+  G.       1/6
+  H.       1/8
+  I.  be   1/12   of an inch.
+  K.       1/16
+  L.       1/24
+  M.       1/32
+  &c----
+There may be added as many more, as the Experimenter shall think fit, with
+holes continually decreasing by known quantities, so far as his senses are
+able to help him; I say, so far, because there may be made _Pipes_ so small
+that it will be impossible to perceive the _perforation_ with ones naked
+eye, though by the help of a _Microscope_, it may easily enough be
+perceived: Nay, I have made a _Pipe_ perforated from end to end, so small,
+that with my naked eye I could very hardly see the body of it, insomuch
+that I have been able to knit it up into a knot without breaking: And more
+accurately examining one with my _Microscope_, I found it not so big as a
+sixteenth part of one of the smaller hairs of my head which was of the
+smaller and finer sort of hair, so that sixteen of these _Pipes_ bound
+faggot-wise together, would but have equalized one single hair; how small
+therefore must its _perforation_ be? It appearing to me through the
+_Microscope_ to be a proportionably _thick-sided Pipe_.
+
+To proceed then, for the trial of the Experiment, the Experimenter must
+place the _Tube_ AB, perpendicular, and fill the _Pipe_ F (cemented into
+the hole E) with water, but leave the _bubble_ C full of _Air_, and then
+gently pouring in water into the Pipe AB, he must observe diligently how
+high the water will rise in it before it protrude the _bubble_ of Air C,
+through the narrow passage of F, and denote exactly the height of the
+_Cylinder_ of water, then cementing in a second Pipe as G, and filling it
+with water; he may proceed as with the former, denoting likewise the height
+of the _Cylinder_ of water, able to protrude the _bubble_ C through the
+passage of G, the like may he do with the next _Pipe_, and the next, &c. as
+far as he is able: then comparing the several heights of the _Cylinders_,
+with the several _holes_ through which each _Cylinder_ did force the _air_
+(having due regard to the _Cylinders_ of water in the small _Tubes_) it
+will be very easie to determine, what force is requisite to press the _Air_
+into such and such _a hole_, or (to apply it to our present experiment) how
+much of the pressure of the _Air_ is taken off by its ingress into smaller
+and smaller _holes_. From the application of which to the entring of the
+_Air_ into the bigger _hole_ of the _Vessel_, and into the smaller _hole_
+of the _Pipe_, we shall clearly find, that there is a greater pressure of
+the air upon the water in the _Vessel_ or greater _pipe_, then there is
+upon that in the lesser _pipe_: For since the pressure of the _air_ every
+way is found to be equal, that is, as much as is able to press up and
+sustain a _Cylinder_ of _Quicksilver_ of two foot and a half high, or
+thereabouts; And since of this pressure so many more degrees are required
+to force the _Air_ into a smaller then into a greater _hole_ that is full
+of a more congruous fluid. And lastly, since those degrees that are
+requisite to press it in, are thereby taken off from the _Air_ within, and
+the _Air_ within left with so many degrees of pressure less then the _Air_
+without; it will follow, that the _Air_ in the less _Tube_ or _pipe_, will
+have less pressure against the superficies of the _water_ therein, then the
+_Air_ in the bigger: which was the minor Proposition to be proved.
+
+The Conclusion therefore will necessarily follow, _viz._ That _this unequal
+pressure of the Air caused by its ingress into unequal holes, is a cause
+sufficient to produce this effect, without the help of any other
+concurrent_; therefore is probably the principal (if not the only) cause of
+these _Phaenomena_.
+
+This therefore being thus explained, there will be divers _Phaenomena_
+explicable thereby, as, the rising of _Liquors_ in a _Filtre_, the rising
+of _Spirit of Wine_, _Oyl_, _melted Tallow_, &c. in the _Week_ of a _Lamp_,
+(though made of small _Wire_, _Threeds_ of _Asbestus_, _Strings_ of
+_Glass_, or the like) the rising of _Liquors_ in a _Spunge_, piece of
+_Bread_, _Sand_, &c. perhaps also the ascending of the _Sap_ in _Trees_ and
+_Plants_, through their small, and some of them _imperceptible pores_, (of
+which I have said more, on another occasion) at least the passing of it out
+of the earth into their roots. And indeed upon the consideration of this
+Principle, multitudes of other uses of it occurr'd to me, which I have not
+yet so well examined and digested as to propound for _Axioms_, but only as
+_Queries_ and _Conjectures_ which may serve as _hints_ toward some further
+_discoveries_.
+
+As first, Upon the consideration of the _congruity_ and _incongruity_ of
+Bodies, as to _touch_, I found also the like _congruity_ and _incongruity_
+(if I may so speak) as to the _Transmitting_ of the _Rates_ of Light: For
+as in this regard, _water_ (not now to mention other Liquors) seems nearer
+of affinity to _Glass_ then _Air_, and _Air_ then _Quicksilver_: whence an
+_oblique Ray_ out of _Glass_, will pass into _water_ with very little
+_refraction_ from the _perpendicular_, but none out of _Glass_ into _Air_,
+excepting a _direct_, will pass without a very great refraction from the
+perpendicular, nay any oblique Ray under thirty degrees, will not be
+admitted into the Air at all. And _Quicksilver_ will neither admit oblique
+or direct, but reflects all; seeming, as to the transmitting of the Raies
+of Light, to be of a quite differing constitution, from that of _Air_,
+_Water_, _Glass_, &c. and to resemble most those opacous and strong
+reflecting bodies of Metals: So also as to the property of cohesion or
+congruity, Water seems to keep the same order, being more congruous to
+Glass then Air, and Air then Quicksilver.
+
+A Second thing (which was hinted to me, by the consideration of the
+included fluids globular form, caused by the protrusion of the ambient
+heterogeneous fluid) was, whether the _Phaenomena_ of gravity might not by
+this means be explained, by supposing the _Globe_ of Earth, Water, and Air
+to be included with a _fluid_, heterogeneous to all and each of them, so
+subtil, as not only to be every where _interspersed_ through the _Air_, (or
+rather the _air_ through it) but to _pervade_ the bodies of _Glass_, and
+even the _closest Metals_, by which means it may endeavour to _detrude_ all
+earthly bodies as far from it as it can; and partly thereby, and partly by
+other of its properties may move them towards the Center of the Earth. Now
+that there is some such fluid, I could produce many Experiments and
+Reasons, that do seem to prove it: But because it would ask some time and
+room to set them down and explain them, and to consider and answer all the
+Objections (many whereof I foresee) that may be alledged against it; I
+shall at present proceed to other _Queries_, contenting my self to have
+here only given a hint of what I may say more elswhere.
+
+A Third _Query_ then was, Whether the _heterogeneity_ of the _ambient
+fluid_ may not be accounted a _secondary cause_ of the _roundness_ or
+_globular form_ of the _greater bodies_ of the world, such as are those of
+the _Sun_, _Stars_, and _Planets_, the _substance_ of each of which seems
+altogether _heterogeneous_ to the _circum-ambient fluid aether_? And of
+this I shall say more in the Observation of the Moon.
+
+A Fourth was, Whether the _globular form_ of the _smaller parcels_ of
+matter here upon the _Earth_, as that of _Fruits_, _Pebbles_, or _Flints_,
+&c. (which seem to have been a _Liquor_ at first) may not be caused by the
+_heterogeneous ambient fluid_. For thus we see that melted _Glass_ will be
+naturally formed into a _round Figure_; so likewise any small Parcel of any
+_fusible body_, if it be perfectly enclosed by the _Air_, will be driven
+into a _globular_ Form; and, when cold, will be found a _solid Ball_. This
+is plainly enough manifested to us by their way of making _shot_ with the
+_drops of Lead_; which being a very pretty curiosity, and known but to a
+very few, and having the liberty of publishing it granted me, by that
+_Eminent Virtuoso_ Sir _Robert Moray_, who brought in this Account of it to
+the _Royal Society_, I have here transcribed and inserted.
+
+To make small shot of different sizes; Communicated by his Highness _P.R._
+
+_Take Lead out of the Pig what quantity you please, melt it down, stir and
+clear it with an iron Ladle, gathering together the blackish parts that
+swim at top like scum, and when you see the colour of the clear Lead to be
+greenish, but no sooner, strew upon it _Auripigmentum_ powdered according
+to the quantity of Lead, about as much as will lye upon a half Crown piece
+will serve for eighteen or twenty pound weight of some sorts of Lead;
+others will require more, or less. After the _Auripigmentum_ is put in,
+stir the Lead well, and the _Auripigmentum_ will flame: when the flame is
+over, take out some of the Lead in a Ladle having a lip or notch in the
+brim for convenient pouring out of the Lead, and being well warmed amongst
+the melted Lead, and with a stick make some single drops of Lead trickle
+out of the Ladle into water in a Glass, which if they fall to be round and
+without tails, there is _Auripigmentum_ enough put in, and the temper of
+the heat is right, otherwise put in more. Then lay two bars of Iron (or
+some more proper Iron-tool made on purpose) upon a Pail of water, and place
+upon them a round Plate of Copper, of the size and figure of an ordinary
+large Pewter or Silver Trencher, the hollow whereof is to be about three
+inches over, the bottom lower then the brims about half an inch, pierced
+with thirty, forty, or more small holes; the smaller the holes are, the
+smaller the shot will be; and the brim is to be thicker then the bottom, to
+conserve the heat the better._
+
+_The bottom of the Trencher being some four inches distant from the water
+in the Pail, lay upon it some burning Coles, to keep the Lead melted upon
+it. Then with the hot Ladle take Lead off the Pot where it stands melted,
+and pour it softly upon the burning Coles over the bottom of the Trencher,
+and it will immediately run through the holes into the water in small round
+drops. Thus pour on new Lead still as fast as it runs through the Trencher
+till all be done; blowing now and then the Coles with hand-Bellows, when
+the Lead in the Trencher cools so as to stop from running._
+
+_While one pours on the Lead, another must, with another Ladle, thrusted
+four or five inches under water in the Pail, catch from time to time some
+of the shot, as it drops down, to see the size of it, and whether there be
+any faults in it. The greatest care is to keep the Lead upon the Trencher
+in the right degree of heat; if it be too cool, it will not run through the
+Trencher, though it stand melted upon it; and this is to be helped by
+blowing the Coals a little, or pouring on new Lead that is hotter: but the
+cooler the Lead, the larger the Shot; and the hotter, the smaller; when it
+it too hot, the drops will crack and fly; then you must stop pouring on new
+Lead, and let it cool; and so long as you observe the right temper of the
+heat, the Lead will constantly drop into very round Shot, without so much
+as one with a tail in many pounds._
+
+_When all is done, take your Shot out of the Pail of water, and put it in a
+Frying-pan over the fire to dry them, which must be done warily, still
+shaking them that they melt not; and when they are dry you may separate the
+small from the great, in Pearl Sives made of Copper or Lattin let into one
+another, into as many sizes at you please. But if you would have your Shot
+larger then the Trencher makes them, you may do it with a Stick, making
+them trickle out of the Ladle, as hath been said._
+
+_If the Trencher be but toucht a very little when the Lead stops from going
+through it, and be not too cool, it will drop again, but it it better not
+to touch it at all. At the melting of the Lead take care that there be no
+kind of Oyl, Grease, or the like, upon the Pots, or Ladles, or Trencher._
+
+_The Chief cause of this Globular Figure of the Shot, seems to be the
+_Auripigmentum_; for, as soon as it is put in among the melted Lead, it
+loses its shining brightness, contracting instantly a grayish film or skin
+upon it, when you scum it to make it clean with the Ladle. So that when the
+Air comes at the falling drop of the melted Lead, that skin constricts them
+every where equally: but upon what account, and whether this be the true
+cause, is left to further disquisition._
+
+Much after this same manner, when the Air is exceeding cold through which
+it passes; do we find the drops of Rain, falling from the Clouds, congealed
+into round Hail-stones by the freezing Ambient.
+
+To which may be added this other known Experiment, That if you gently let
+fall a drop of _water_ upon small _sand_ or _dust_, you shall find, as it
+were, an artificial _round stone_ quickly generated. I cannot upon this
+occasion omit the mentioning of the strange kind of _Grain_, which I have
+observed in a _stone_ brought from _Kettering_ in _Northamptonshire_, and
+therefore called by Masons _Kettering-Stone_, of which see the Description.
+Which brings into my mind what I long since observed in the fiery Sparks
+that are struck out of a Steel. For having a great desire to see what was
+left behind, after the Spark was gone out, I purposely struck fire over a
+very white piece of Paper, and observing diligently where some conspicuous
+sparks went out, I found a very little black spot no bigger then the point
+of a Pin, which through a _Microscope_ appeared to be a perfectly round
+Ball, looking much like a polisht ball of Steel, insomuch that I was able
+to see the Image of the window reflected from it. I cannot here stay
+(having done it more fully in another place) to examine the particular
+Reasons of it, but shall only hint, that I imagine it to be some small
+parcel of the Steel, which by the violence of the motion of the stroke
+(most of which seems to be imprest upon those small parcels) is made so
+glowing hot, that it is melted into a _Vitrum_, which by the ambient Air is
+thrust into the form of a Ball.
+
+A Fifth thing which I thought worth Examination was, Whether the motion of
+all kind of Springs, might not be reduced to the Principle whereby the
+included _heterogeneous fluid_ seems to be moved; or to that whereby two
+Solids, as Marbles, or the like, are thrust and kept together by the
+_ambient fluid_.
+
+A Sixth thing was, Whether the Rising and Ebullition of the Water out of
+Springs and Fountains (which lie much higher from the Center of the Earth
+then the Superficies of the Sea, from whence it seems to be derived) may
+not be explicated by the rising of Water in a smaller Pipe: For the
+Sea-water being strained through the Pores or Crannies of the Earth, is, as
+it were, included in little Pipes, where the pressure of the Air has not so
+great a power to resist its rising: But examining this way, and finding in
+it several difficulties almost irremovable, I thought upon a way that would
+much more naturally and conceivably explain it, which was by this following
+Experiment: I took a Glass-Tube, of the form of that described in the sixth
+Figure, and chusing two _heterogeneous fluids_, such as Water and Oyl, I
+poured in as much Water as filled up the Pipes as high as AB, then putting
+in some Oyl into the Tube AC, I deprest the superficies A of the Water to
+F, and B I raised to G, which was not so high perpendicularly as the
+superficies of the Oyl F, by the space FI, wherefore the proportion of the
+gravity of these two Liquors was as GH to FE.
+
+This Experiment I tried with several other Liquors, and particularly with
+fresh Water and Salt (which I made by dissolving Salt in warm Water) which
+two though they are nothing heterogeneous, yet before they would perfectly
+mix one with another, I made trial of the Experiment: Nay, letting the Tube
+wherein I tried the Experiment remain for many dayes, I observed them not
+to mix; but the superficies of the fresh was rather more then less elevated
+above that of the Salt. Now the proportion of the gravity of Sea-water, to
+that of River-water, according to _Stevinus_ and _Varenius_, and as I have
+since found pretty true by making trial my self, is as 46. to 45. that is,
+46. Ounces of the salt Water will take up no more room then 45. of the
+fresh. Or reciprocally 45 pints of salt-water weigh as much as 46 of fresh.
+
+But I found the proportion of Brine to fresh Water to be near 13 to 12:
+Supposing therefore GHM to represent the Sea, and FI the height of the
+Mountain above the Superficies of the Sea, FM a Cavern in the Earth,
+beginning at the bottom of the Sea, and terminated at the top of the
+Mountain, LM the Sand at the bottom, through which the Water is as it were
+strained, so as that the fresher parts are only permitted to transude, and
+the saline kept back; if therefore the proportion of G M to FM be as 45 to
+46, then may the Cylinder of Salt-water GM make the Cylinder of Fresh-water
+to rise as high as E, and to run over at N. I cannot here stand to examine
+or confute their Opinion, who make the depth of the Sea, below its
+Superficies, to be no more perpendicularly measured then the height of the
+Mountains above it: 'Tis enough for me to say, there is no one of those
+that have asserted it, have experimentally known the perpendicular of
+either; nor shall I here determine, whether there may not be many other
+causes of the separation of the fresh water from the salt, as perhaps some
+parts of the Earth through which it is to pass, may contain a Salt, that
+mixing and uniting with the Sea-salt, may precipitate it; much after the
+same manner as the _Alkalizate_ and _Acid Salts_ mix and precipitate each
+other in the preparation of _Tartarum Vitriolatum._ I know not also whether
+the exceeding cold (that must necessarily be) at the bottom of the Water,
+may not help towards this separation, for we find, that warm Water is able
+to dissolve and contain more Salt, then the same cold; insomuch that Brines
+strongly impregnated by heat, if let cool, do suffer much of their Salt to
+subside and crystallize about the bottom and sides. I know not also whether
+the exceeding pressure of the parts of the Water one against another, may
+not keep the Salt from descending to the very bottom, as finding little or
+no room to insert it self between those parts, protruded so violently
+together, or else squeeze it upwads into the superiour parts of the Sea,
+where it may more easily obtain room for it self, amongst the parts of the
+Water, by reason that there is more heat and less pressure. To this Opinion
+I was somewhat the more induced by the relations I have met with in
+_Geographical Writers_, of drawing fresh Water from the bottom of the Sea,
+which is salt above. I cannot now stand to examine, whether this natural
+perpetual motion may not artificially be imitated: Nor can I stand to
+answer the Objections which may be made against this my Supposition: As,
+First, How it comes to pass, that there are sometimes salt Springs much
+higher then the Superficies of the Water? And, Secondly, Why Springs do not
+run faster and slower, according to the varying height made of the Cylinder
+of Sea-water, by the ebbing and flowing of the Sea?
+
+As to the First, In short, I say, the fresh Water may receive again a
+saline Tincture near the Superficies of the Earth, by passing through some
+salt _Mines_, or else many of the saline parts of the Sea may be kept back,
+though not all.
+
+And as to the Second, The same _Spring_ may be fed and supplyed by divers
+_Caverns_, coming from very far distant parts of the _Sea_, so as that it
+may in one place be _high_, in another _low water_; and so by that means
+the _Spring_ may be equally supply'd at all times. Or else the _Cavern_ may
+be so straight and narrow, that the water not having so ready and free
+passage through it, cannot upon so short and quick mutations of pressure,
+be able to produce any sensible effect at such a distance. Besides that, to
+confirm this _hypothesis_, there are many _Examples_ found in _Natural
+Historians_, of _Springs_ that do ebb and flow like the Sea: As
+particularly, those recorded by the Learned _Camden_, and after him by
+_Speed,_ to be found in this _Island_: One of which, they relate to be on
+the Top of a Mountain, by the small Village _Kilken_ in _Flintshire_,
+_Maris aemulus qui statis temporibus suos evomit & resorbet Aquas_; Which
+at certain times riseth and falleth after the manner of the Sea. A Second
+in _Caermardenshire,_ near _Caermarden_, at a place called _Cantred
+Bichan_; _Qui (ut scribit Giraldus) naturali die bis undis deficiens, &
+toties exuberans, marinas imitatur instabilitates_; That twice in four and
+twenty hours ebbing and flowing; resembleth the unstable motions of the
+Sea. The _Phaenomena_ of which two may be easily made out, by supposing the
+_Cavern_, by which they are fed, to arise from the bottom of the next Sea.
+A Third, is a Well upon the River _Ogmore_ in _Glamorganshire_, and near
+unto _Newton_, of which _Camden_ relates himself to be certified, by a
+Letter from a Learned Friend of his that observed it, _Fons abest hinc,
+&c._ The Letter is a little too long to be inserted, but the substance is
+this; That this Well ebbs and flows quite contrary to the flowing and
+ebbing of the Sea in those parts: for 'tis almost empty at Full Sea, but
+full at Low water. This may happen from the Channel by which it is
+supplied, which may come from the bottom of a Sea very remote from those
+parts, and where the Tides are much differing from those of the approximate
+shores. A Fourth, lies in _Westmorland_, near the River _Leder_; _Qui
+instar Euripi saepius in die reciprocantibus undis fluit & refluit_, which
+ebbs and flows many times a day. This may proceed from its being supplyed
+from many Channels, coming from several parts of the Sea, lying
+sufficiently distant asunder to have the times of High-water differing
+enough one from the other; so as that whensoever it shall be High water
+over any of those places, where these Channels begin, it shall likewise be
+so in the Well; but this is but a supposition.
+
+A Seventh _Query_ was, Whether the _dissolution_ or mixing of several
+bodies, whether fluid or solid, with saline or other Liquors, might not
+partly be attributed to this Principle of the congruity of those bodies and
+their dissolvents? As of Salt in Water, Metals in several _Menstruums_,
+Unctuous Gums in Oyls, the mixing of Wine and Water, &c. And whether
+_precipitation_ be not partly made from the same Principle of Incongruity?
+I say _partly_, because there are in some Dissolutions, some other Causes
+concurrent.
+
+I shall lastly make a much more seemingly strange and unlikely _Query_; and
+that is, Whether this Principle, well examined and explained, may not be
+found a _co-efficient_ in the most considerable Operations of Nature? As in
+those of _Heat_, and _Light_ consequently of _Rarefaction_ and
+_Condensation_, _Hardness_, and _Fluidness_, _Perspicuity_ and
+_Opacousness_, _Refractions_ and _Colours. &c._ Nay, I know not whether
+there may be many things done in Nature, in which this may not (be said to)
+have a Finger? This I have in some other passages of this Treatise further
+enquired into and shewn, that as well _Light_ as _Heat_ may be caused by
+_corrosion_, which is applicable to _congruity_, and consequently all the
+rest will be but _subsequents_: In the mean time I would not willingly be
+guilty of that _Error_, which the thrice Noble and Learned _Verulam_ justly
+takes notice of, as such, and calls _Philosophiae Genus Empiricum, quod in
+paucorum Experimentorum Angustiis & Obscuritate fundatum est_. For I
+neither conclude from one single Experiment, nor are the Experiments I make
+use of all made upon one Subject: Nor wrest I any Experiment to make it
+_quadrare_ with any preconceiv'd Notion. But on the contrary, I endeavour
+to be conversant in divers kinds of Experiments, and all and every one of
+those Trials, I make the Standards or Touchstones, by which I try all my
+former Notions, whether they hold out in weight, and measure, and touch,
+&c. For as that Body is no other then a Counterfeit Gold, which wants any
+one of the Proprieties of Gold, (such as are the Malleableness, Weight,
+Colour, Fixtness in the Fire, Indissolubleness in _Aqua fortis_, and the
+like) though it has all the other; so will all those Notions be found to be
+false and deceitful, that will not undergo all the Trials and Tests made of
+them by Experiments. And therefore such as will not come up to the desired
+_Apex_ of Perfection, I rather wholly reject and take new, then by piecing
+and patching, endeavour to retain the old, as knowing such things at best
+to be but lame and imperfect. And this course I learned from Nature; whom
+we find neglectful of the old Body, and suffering its Decaies and
+Infirmities to remain without repair, and altogether sollicitous and
+careful of perpetuating the _Species_ by new _Individuals_. And it is
+certainly the most likely way to erect a glorious Structure and Temple to
+_Nature_, such as she will be found (by any _zealous Votary_) to reside in;
+to begin to build a new upon a sure Foundation of Experiments.
+
+But to digress no further from the consideration of the _Phaenomena,_ more
+immediately explicable by this Experiment, we shall proceed to shew, That,
+as to the rising of Water in a _Filtre_, the reason of it will be manifest
+to him, that does take notice, that a _Filtre_ is constituted of a great
+number of small long solid bodies, which lie so close together, that the
+Air in its getting in between them, doth lose of its pressure that it has
+against the _Fluid_ without them, by which means the Water or Liquor not
+finding so strong a resistance between them as is able to counter-ballance
+the pressure on its superficies without, is raised upward, till it meet
+with a pressure of the Air which is able to hinder it. And as to the Rising
+of Oyl, melted Tallow, Spirit of Wine, &c. in the Week of a Candle or Lamp,
+it is evident, that it differs in nothing from the former, save only in
+this, that in a _Filtre_ the Liquor descends and runs away by another part;
+and in the Week the Liquor is dispersed and carried away by the Flame;
+something there is ascribable to the Heat, for that it may rarifie the more
+volatil and spirituous parts of those combustible Liquors, and so being
+made lighter then the Air, it maybe protruded upwards by that more
+ponderous fluid body in the Form of Vapours; but this can be ascribed to
+the ascension of but a very little, and most likely of that only which
+ascends without the Week. As for the Rising of it in a Spunge, Bread,
+Cotton, &c. above the superficies of the subjacent Liquor, what has been
+said about the _Filtre_ (if considered) will easily suggest a reason,
+considering that all these bodies abound with small holes or pores.
+
+From this same Principle also (_viz. the unequal pressure of the Air
+against the unequal superficies of the water_) proceeds the cause of the
+accession or incursion of any floating body against the sides of the
+containing Vessel; or the _appropinquation_ of two floating bodies, as
+_Bubbles_, _Corks_, _Sticks_, _Straws_, &c. one towards another. As for
+instance, Take a Glass-jar, such as AB in the seventh _Figure_, and filling
+it pretty near the top with water, throw into it a small round piece of
+Cork, as C, and plunge it all over in water, that it be wet, so as that the
+water may rise up by the sides of it, then placing it any where upon the
+superficies, about an inch, or one inch and a quarter from any side, and
+you shall perceive it by degrees to make _perpendicularly_ toward the
+nearest part of the side, and the nearer it approaches, the faster to be
+moved, the reason of which _Phaenomenon_ will be found no other then this,
+that the Air has a greater pressure against the middle of the
+_superficies_, then it has against those parts that approach nearer, and
+are _contiguous_ to the sides. Now that the pressure is greater, may (as I
+shewed before in the explication of the third _Figure_) be evinced from the
+flatting of the water in the middle, which arises from the gravity of the
+under _fluid_: for since, as I shewed before, if there were no gravity in
+the under _fluid_, or that it were equal to that of the upper, the
+terminating Surface would be _Spherical_, and since it is the additional
+pressure of the gravity of water that makes it so flat, it follows, that
+the pressure upon the middle must be greater then towards the sides. Hence
+the Ball having a stronger pressure against that side of it which respects
+the middle of the _superficies_, then against that which respects the
+_approximate_ side, must necessarily move towards that part, from whence it
+finds least resistance, and so be _accelerated_, as the resistance
+decrease. Hence the more the water is raised under that part of its way it
+is passing above the middle, the faster it is moved: And therefore you will
+find it to move faster in E then in D, and in D then in C. Neither could I
+find the floating substance to be moved at all, until it were placed upon
+some part of the _Superficies_ that was sensibly elevated above the height
+of the middle part. Now that this may be the true cause, you may try with a
+blown Bladder, and an exactly round Ball upon a very smooth side of some
+pliable body, as _Horn_ or _Quicksilver._ For if the Ball be placed under a
+part of the Bladder which is upon one side of the middle of its pressure,
+and you press strongly against the Bladder, you shall find the Ball moved
+from the middle towards the sides.
+
+Having therefore shewn the reason of the motion of any float towards the
+sides, the reason of the incursion of any two floating bodies will easily
+appear: For the rising of the water against the sides of either of them, is
+an Argument sufficient, to shew the pressure of the Air to be there less,
+then it is further from it, where it is not so much elevated; and therefore
+the reason of the motion of the other toward it, will be the same as
+towards the side of the Glass, only here from the same reason, they are
+mutually moved toward each other, whereas the side of the Glass in the
+former remains fixt. If also you gently fill the Jar so full with water,
+that the water is _protuberant_ above the sides, the same piece of Cork
+that before did hasten towards the sides, does now fly from it as fast
+towards the middle of the Superficies; the reason of which will be found no
+other then this, that the pressure of the Air is stronger against the sides
+of the Superficies G and H, then against the middle I; for since, as I
+shewed before, the Principle of congruity would make the terminating
+Surface Spherical, and that the flatting of the Surface in the middle is
+from the abatement of the waters pressure outwards, by the contrary
+indeavour of its gravity; it follows that the pressure in the middle must
+be less then on the sides; and therefore the consecution will be the same
+as in the former. It is very odd to one that considers not the reason of
+it, to see two floating bodies of wood to approach each other, as though
+they were indued with some magnetical vigour; which brings into my mind
+what I formerly tried with a piece of Cork or such like body, which I so
+ordered, that by putting a little stick into the same water, one part of
+the said Cork would approach and make toward the stick, whereas another
+would discede and fly away, nay it would have a kind of verticity, so as
+that if the _AEquator_ (as I may so speak) of the Cork were placed towards
+the stick, if let alone, it would instantly turn its appropriate Pole
+toward it, and then run a-tilt at it: and this was done only by taking a
+dry Cork, and wetting one side of it with one small stroak; for by this
+means gently putting it upon the water, it would depress the superficies on
+every side of it that was dry, and therefore the greatest pressure of the
+Air, being near those sides, caused it either to chase away, or else to fly
+off from any other floating body, whereas that side only, against which the
+water ascended, was thereby able to attract.
+
+It remains only, that I should determine how high the Water or other Liquor
+may by this means be raised in a smaller Pipe above the Superficies of that
+without it, and at what height it may be sustained: But to determine this,
+will be exceeding difficult, unless I could certainly know how much of the
+Airs pressure is taken off by the smalness of such and such a Pipe, and
+whether it may be wholly taken off, that is, whether there can be a hole or
+pore so small, into which Air could not at all enter, though water might
+with its whole force, for were there such, 'tis manifest, that the water
+might rise in it to some five or six and thirty English Foot high. I know
+not whether the capillary Pipes in the bodies of small Trees, which we call
+their _Microscopical pores_, may not be such; and whether the congruity of
+the sides of the Pore may not yet draw the juyce even higher then the Air
+was able by its bare pressure to raise it: For, Congruity is a principle
+that not only unites and holds a body joyned to it, but, which is more,
+attracts and draws a body that is very near it, and holds it above its
+usual height.
+
+And this is obvious even in a drop of water suspended under any Similar or
+Congruous body: For, besides the ambient pressure that helps to keep it
+sustein'd, there is the Congruity of the bodies that are contiguous. This
+is yet more evident in Tenacious and Glutinous bodies; such as Gummous
+Liquors, Syrups, Pitch, and Rosin melted, &c. Tar, Turpentine, Balsom,
+Bird-lime, &c. for there it is evident, that the Parts of the tenacious
+body, as I may so call it, do stick and adhere so closely together, that
+though drawn out into long and very slender Cylinders, yet they will not
+easily relinquish one another; and this, though the bodies be _aliquatenus_
+fluid, and in motion by one another, which, to such as consider a fluid
+body only as its parts are in a confused irregular motion, without taking
+in also the congruity of the parts one among another, and incongruity to
+some other bodies, does appear not a little strange. So that besides the
+incongruity of the ambient fluid to it, we are to consider also the
+congruity of the parts of the contein'd fluid one with another.
+
+And this Congruity (that I may here a little further explain it) is both a
+Tenaceous and an Attractive power; for the Congruity, in the Vibrative
+motions, may be the cause of all kind of attraction, not only Electrical,
+but Magnetical also, and therefore it may be also of Tenacity and
+Glutinousness. For, from a perfect congruity of the motions of two distant
+bodies, the intermediate fluid particles are separated and droven away from
+between them, and thereby those congruous bodies are, by the incompassing
+mediums, compell'd and forced neerer together; wherefore that
+attractiveness must needs be stronger, when, by an immediate contact, they
+are forc'd to be exactly the same: As I shew more at large in my _Theory_
+of the _Magnet_. And this hints to me the reason of the suspension of the
+_Mercury_ many inches, nay many feet, above the usual station of 30 inches.
+For the parts of _Quick-Silver,_ being so very similar and congruous to
+each other, if once united, will not easily suffer a divulsion: And the
+parts of water, that were any wayes _heterogeneous_, being by _exantlation_
+or rarefaction exhausted, the remaining parts being also very similar, will
+not easily part neither. And the parts of the Glass being solid, are more
+difficultly disjoyn'd; and the water, being somewhat similar to both, is,
+as it were, a medium to unite both the _Glass_ and the _Mercury_ together.
+So that all three being united, and not very dissimilar, by means of this
+contact, if care be taken that the Tube in erecting be not shogged, the
+_Quicksilver_ will remain suspended, notwithstanding its contrary indeavour
+of Gravity, a great height above its ordinary Station; but if this
+immediate Contact be removed, either by a meer separation of them one from
+another by the force of a shog, whereby the other becomes imbodied between
+them, and licks up from the surface some agil parts, and so hurling them
+makes them air, or else by some small heterogeneous agil part of the Water,
+or Air, or Quicksilver, which appears like a bubble, and by its jumbling to
+and fro there is made way for the _heterogeneous AEther_ to obtrude it self
+between the Glass and either of the other Fluids, the Gravity of _Mercury
+precipitates_ it downward with very great violence; and if the Vessel that
+holds the restagnating _Mercury_ be convenient, the _Mercury_ will for a
+time _vibrate_ to and fro with very large _reciprocations_, and at last
+will remain kept up by the pressure of the external Air at the height of
+neer thirty inches. And whereas it may be objected, that it cannot be, that
+the meer imbodying of the _AEther_ between these bodies can be the cause,
+since the _AEther_ having a free passage alwayes, both through the Pores of
+the Glass, and through those of the Fluids, there is no reason why it
+should not make a separation at all times whilst it remains suspended, as
+when it is violently dis-joyned by a shog. To this I answer, That though
+the _AEther_ passes between the Particles, that is, through the Pores of
+bodies, so as that any chasme or separation being made, it has infinite
+passages to admit its entry into it, yet such is the tenacity or attractive
+virtue of Congruity, that till it be overcome by the meer strength of
+Gravity, or by a shog assisting that Conatus of Gravity, or by an agil
+Particle, that is like a leaver agitated by the _AEther_; and thereby the
+parts of the congruous substances are separated so far asunder, that the
+strength of congruity is so far weakened, as not to be able to reunite
+them, the parts to be taken hold of being removed out of the attractive
+Sphere, as I may so speak, of the congruity; such, I say, is the tenacity
+of congruity, that it retains and holds the almost contiguous Particles of
+the Fluid, and suffers them not to be separated, till by meer force that
+attractive or retentive faculty be overcome: But the separation being once
+made beyond the Sphere of the attractive activity of congruity, that virtue
+becomes of no effect at all, but the _Mercury_ freely falls downwards till
+it meet with a resistance from the pressure of the _ambient_ Air, able to
+resist its gravity, and keep it forced up in the Pipe to the height of
+about thirty inches.
+
+Thus have I gently raised a Steel _pendulum_ by a Loadstone to a great
+Angle, till by the shaking of my hand I have chanced to make a separation
+between them, which is no sooner made, but as if the Loadstone had retained
+no attractive virtue, the _Pendulum_ moves freely from it towards the other
+side. So vast a difference is there between the attractive virtue of the
+_Magnet_ when it acts upon a contiguous and upon a disjoyned body: and much
+more must there be between the attractive virtues of congruity upon a
+contiguous and disjoyned body; and in truth the attractive virtue is so
+little upon a body disjoyned, that though I have with a _Microscope_
+observed very diligently, whether there were any extraordinary
+_protuberance_ on the side of a drop of water that was exceeding neer to
+the end of a green stick, but did not touch it, I could not perceive the
+least; though I found, that as soon as ever it toucht it the whole drop
+would presently unite it self with it; so that it seems an absolute contact
+is requisite to the exercising of the tenacious faculty of congruity.
+
+       *       *       *       *       *
+
+
+Observ. VII. _Of some _Phaenomena_ of Glass drops._
+
+These _Glass Drops_ are small parcels of coarse green Glass taken out of
+the Pots that contain the _Metal_ (as they call it) in fusion, upon the end
+of an Iron Pipe; and being exceeding hot, and thereby of a kind of sluggish
+fluid Confidence, are suffered to drop from thence into a Bucket of cold
+Water, and in it to lye till they be grown sensibly cold.
+
+Some of these I broke in the open air, by snapping off a little of the
+small stem with my fingers, others by crushing it with a small pair of
+Plyers; which I had no sooner done, then the whole bulk of the drop flew
+violently, with a very brisk noise, into multitudes of small pieces, some
+of which were as small as dust, though in some there were remaining pieces
+pretty large, without any flaw at all, and others very much flaw'd, which
+by rubbing between ones fingers was easily reduced to dust; these dispersed
+every way so violently, that some of them pierced my skin. I could not find
+either with my naked Eye, or a _Microscope_, that any of the broken pieces
+were of a regular figure, nor any one like another, but for the most part
+those that flaw'd off in large pieces were prettily branched.
+
+The ends of others of these drops I nipt off whilst all the bodies and ends
+of them lay buried under the water, which, like the former, flew all to
+pieces with as brisk a noise, and as strong a motion.
+
+Others of these I tried to break, by grinding away the blunt end, and
+though I took a seemingly good one, and had ground away neer two thirds of
+the Ball, yet would it not fly to pieces, but now and then some small rings
+of it would snap and fly off, not without a brisk noise and quick motion,
+leaving the Surface of the drop whence it flew very prettily branched or
+creased, which was easily discoverable by the _Microscope_. This drop,
+after I had thus ground it, without at all impairing the remnant that was
+not ground away, I caused to fly immediately all into sand upon the nipping
+off the very tip of its slender end.
+
+Another of these drops I began to grind away at the smaller end, but had
+not worn away on the stone above a quarter of an inch before the whole drop
+flew with a brisk crack into sand or small dust; nor would it have held so
+long, had there not been a little flaw in the piece that I ground away, as
+I afterwards found.
+
+Several others of these drops I covered over with a thin but very tuff skin
+of _Icthyocolla_, which being very tough and very transparent, was the most
+convenient substance for these tryals that I could imagine, having dipt, I
+say, several of these drops in this transparent Glue whilst hot, and
+suffering them to hang by a string tied about the end of them till they
+were cold, and the skin pretty tough; then wrapping all the body of the
+drop (leaving out only the very tip) in fine supple Kids-leather very
+closely, I nipped off the small top, and found, as I expected, that
+notwithstanding this skin of Glue, and the close wrapping up in Leather,
+upon the breaking of the top, the drop gave a crack like the rest, and gave
+my hand a pretty brisk impulse: but yet the skin and leather was so strong
+as to keep the parts from flying out of their former posture; and, the skin
+being transparent, I found that the drop retained exactly its former figure
+and polish, but was grown perfectly opacous and all over flaw'd, all those
+flaws lying in the manner of rings, from the bottom or blunt end, to the
+very top or small point. And by several examinations with a _Microscope_,
+of several thus broken, I found the flaws, both within the body of the
+drop, and on the outward surface, to lye much in this order.
+
+Let AB in the Figure X of the fourth Scheme represent the drop cased over
+with _Icthyocolla_ or _Isinglass_, (by being ordered as is before
+prescribed) crazed or flawed into pieces, but by the skin or case kept in
+its former figure, and each of its flawed parts preserved exactly in its
+due posture; the outward appearance of it somewhat plainly to the naked
+eye, but much more conspicuous if viewed with a small lens appeared much
+after this shape. That is, the blunt end B for a pretty breadth, namely, as
+far as the Ring CCC seemed irregularly flawed with divers clefts, which all
+seemed to tend towards the Center of it, being, as I afterwards found, and
+shall anon shew in the description of the figure Y, the Basis, as it were,
+of a Cone, which was terminated a little above the middle of the drop, all
+the rest of the Surface from CCC to A was flawed with an infinite number of
+small and parallel Rings, which as they were for the most part very round,
+so were they very thick and close together, but were not so exactly flaw'd
+as to make a perfect Ring, but each circular part was by irregular cracks
+flawed likewise into multitudes of irregular flakes or tiles; and this
+order was observed likewise the whole length of the neck.
+
+Now though I could not so exactly cut this _conical Body_ through the
+_Axis_, as is represented by the figure Y; yet by _anatomizing_, as it
+were, of several, and taking notice of divers particular circumstances, I
+was informed, that could I have artificially divided a flaw'd drop through
+the _Axis_ or _Center_, I should with a _Microscope_ have found it to
+appear much of this form, where A signifies the _Apex_, and B the blunt
+end, CC the Cone of the Basis, which is terminated at T the top or end of
+it, which seems to be the very middle of the blunt end in which, not only
+the conical body of the Basis CC is terminated, but as many of the parts of
+the drop as reach as high as DD.
+
+And it seemed to be the head or beginning of a Pith, as it were, or a part
+of the body which seemed more spungy then the rest, and much more
+irregularly flawed, which from T ascended by EE, though less visible, into
+the small neck towards A. The Grain, as it were, of all the flaws, that
+proceeds from all the outward Surface ADCCDA, was much the same, as is
+represented by the black strokes that meet in the middle DT, DT, DE, DE,
+&c.
+
+Nor is this kind of Grain, as I may call it, peculiar to Glass drops thus
+quenched; for (not to mention _Coperas-stones_, and divers other
+_Marchasites_ and _Minerals_, which I have often taken notice of to be in
+the very same manner flaked or grained, with a kind of Pith in the middle)
+I have observed the same in all manner of cast Iron, especially the coarser
+sort, such as Stoves, and Furnaces, and Backs, and Pots are made of: For
+upon the breaking of any of those Substances it is obvious to observe, how
+from the out-sides towards the middle, there is a kind of Radiation or
+Grain much resembling this of the Glass-drop; but this Grain is most
+conspicuous in Iron-bullets, if they be broken: the same _Phaenomena_ may
+be produced by casting _regulus_ of _Antimony_ into a Bullet-mold, as also
+with _Glass of Antimony_, or with almost any such kind of _Vitrified
+substance_, either cast into a cold Mold or poured into Water.
+
+Others of these Drops I heat red hot in the fire, and then suffered them to
+cool by degrees. And these I found to have quite lost all their
+_fulminating_ or flying quality, as also their hard, brittle and springy
+texture; and to emerge of a much softer temper, and much easier to be
+broken or snapt with ones finger; but its strong and brittle quality was
+quite destroyed, and it seemed much of the same consistence with other
+green Glass well nealed in the Oven.
+
+The Figure and bigness of these for the most part was the same with that of
+the Figure Z; that is, all the surface of them was very smooth and polisht,
+and for the most part round, but very rugged or knobbed about D, and all
+the length of the stem was here and there pitted or flatted. About D, which
+is at the upper part of the drop under that side of the stem which is
+concave, there usually was made some one or more little Hillocks or
+Prominences. The drop it self, before it be broken, appears very
+transparent, and towards the middle of it, to be very full of small
+Bubbles, of some kind of aerial substance, which by the refraction of the
+outward surface appear much bigger then really they are, and this may be in
+good part removed, by putting the drop under the surface of clear Water,
+for by that means most part of the refraction of the convex Surface of the
+drop is destroyed, and the bubbles will appear much smaller. And this, by
+the by, minds me of the appearing magnitude of the _aperture_ of the
+_iris_, or _pupil_ of the eye, which though it appear, and be therefore
+judged very large, is yet not above a quarter of the bigness it appears of,
+by the _lenticular_ refraction of the _Cornea_.
+
+The cause of all which _Phaenomena_ I imagine to be no other then this,
+That the Parts of the Glass being by the excessive heat of the fire kept
+off and separated one from another, and thereby put into a kind of sluggish
+fluid consistence, are suffered to drop off with that heat or agitation
+remaining in them, into cold Water; by which means the outsides of the drop
+are presently cool'd and _crusted_, and are thereby made of a loose
+texture, because the parts of it have not time to settle themselves
+leisurely together, and so to lie very close together: And the innermost
+parts of the drop, retaining still much of their former heat and
+agitations, remain of a loose texture also, and, according as the cold
+strikes inwards from the bottom and sides, are quenched, as it were, and
+made rigid in that very posture wherein the cold finds them. For the parts
+of the _crust_ being already hardened, will not suffer the parts to shrink
+any more from the outward Surface inward; and though it shrink a little by
+reason of the small parcels of some Aerial substances dispersed through
+the matter of the Glass, yet that is not neer so much as it appears (as I
+just now hinted;) nor if it were, would it be sufficient for to consolidate
+and condense the body of Glass into a _tuff_ and close _texture_, after it
+had been so excessively rarified by the heat of the glass-Furnace.
+
+But that there may be such an expansion of the aerial substance contained
+in those little _blebbs_ or bubbles in the body of the drop, this following
+Experiment will make more evident.
+
+       *       *       *       *       *
+
+Take a small Glass-Cane about a foot long, seal up one end of it
+_hermetically_, then put in a very small bubble of Glass, almost of the
+shape of an Essence-viol with the open mouth towards the sealed end, then
+draw out the other end of the Pipe very small, and fill the whole Cylinder
+with water, then set this Tube by the Fire till the Water begin to boyl,
+and the Air in the bubble be in good part rarified and driven out, then by
+sucking at the smalling Pipe, more of the Air or vapours in the bubble may
+be suck'd out, so that it may sink to the bottom; when it is sunk to the
+bottom, in the flame of a Candle, or Lamp, nip up the slender Pipe and let
+it cool: whereupon it is obvious to observe, first, that the Water by
+degrees will subside and shrink into much less room: Next, that the Air or
+vapours in the Glass will expand themselves so, as to buoy up the little
+Glass: Thirdly, that all about the inside of the Glass-pipe there will
+appear an infinite number of small bubbles, which as the Water grows colder
+and colder will swell bigger and bigger, and many of them buoy themselves
+up and break at the top.
+
+From this _Disceding_ of the heat in Glass drops, that is, by the quenching
+or cooling Irradiations propagated from the Surface upwards and inwards, by
+the lines CT, CT, DT, DE, &c. the bubbles in the drop have room to expand
+themselves a little, and the parts of the Glass contract themselves; but
+this operation being too quick for the sluggish parts of the Glass, the
+contraction is performed very unequally and irregularly, and thereby the
+Particles of the Glass are bent, some one way, and some another, yet so as
+that most of them draw towards the Pith or middle TEEE, or rather from that
+outward: so that they cannot _extricate_ or unbend themselves, till some
+part of TEEE be broken and loosened, for all the parts about that are
+placed in the manner of an Arch, and so till their hold at TEEE be loosened
+they cannot fly asunder, but uphold, and shelter, and fix each other much
+like the stones in a Vault, where each stone does concurre to the stability
+of the whole Fabrick, and no one stone can be taken away but the whole Arch
+falls. And wheresoever any of those radiating wedges DTD, &c. are removed,
+which are the component parts of this Arch, the whole Fabrick presently
+falls to pieces; for all the Springs of the several parts are set at
+liberty, which immediately extricate themselves and fly asunder every way;
+each part by its spring contributing to the darting of it self and some
+other contiguous part. But if this drop be heat so hot as that the parts by
+degrees can unbend themselves, and be settled and annealed in that posture,
+and be then suffered gently to subside and cool; The parts by this nealing
+losing their springiness, constitute a drop of a more soft but less brittle
+texture, and the parts being not at all under a flexure, though any part of
+the middle or Pith TEEE be broken, yet will not the drop at all fly to
+pieces as before.
+
+This Conjecture of mine I shall indeavour to make out by explaining each
+particular Assertion with _analogous_ Experiments: The Assertions are
+there.
+
+    First, That the parts of the Glass, whilst in a fluid Consistence and
+    hot, are more rarified, or take up more room, then when hard and cold.
+
+    Secondly, That the parts of the drop do suffer a twofold contraction.
+
+    Thirdly, That the dropping or quenching the glowing metal in the Water
+    makes it of a hard, springing, and rarified texture.
+
+    Fourthly, That there is a flexion or force remaining upon the parts of
+    the Glass thus quenched, from which they indeavour to extricate
+    themselves.
+
+    Fifthly, That the Fabrick of the drop, that is able to hinder the parts
+    from extricating themselves, is _analogus_ to that of an Arch.
+
+    Sixthly, That the sudden flying asunder of the parts proceeds from
+    their springiness.
+
+    Seventhly, That a gradual heating and cooling does anneal or reduce the
+    parts of Glass to a texture that is more loose, and easilier to be
+    broken, but not so brittle.
+
+That the first of these is true may be gathered from this, That _Heat is a
+property of a body arising from the motion or agitation of its parts_; and
+therefore whatever body is thereby toucht must necessarily receive some
+part of that motion, whereby its parts will be shaken and agitated, and so
+by degrees free and extricate themselves from one another, and each part so
+moved does by that motion _exert_ a _conatus_ of _protruding_ and
+displacing all the adjacent Particles. Thus Air included in a vessel, by
+being heated will burst it to pieces. Thus have I broke a Bladder held over
+the fire in my hand, with such a violence and noise, that it almost made me
+deaf for the present, and much surpassed the noise of a Musket: The like
+have I done by throwing into the fire small glass Bubbles hermetically
+sealed, with a little drop of Water included in them. Thus Water also, or
+any other Liquor, included in a convenient vessel, by being warmed,
+manifestly expands it self with a very great violence, so as to break the
+strongest vessel, if when heated it be narrowly imprisoned in it. This is
+very manifest by the _Sealed Thermometers_, which I have, by several
+tryals, at last brought to a great certainty and tenderness: for I have
+made some with stems above four foot long, in which the expanding Liquor
+would so far vary, as to be very neer the very top in the heat of Summer,
+and prety neer the bottom at the coldest time of the Winter. The Stems I
+use for them are very thick, straight, and even Pipes of Glass, with a very
+small _perforation_, and both the head and body I have made on purpose at
+the Glass-house, of the same metal whereof the Pipes are drawn: these I can
+easily in the flame of a Lamp, urged with the blast of a pair of Bellows,
+seal and close together, so as to remain very firm, close and even; by this
+means I joyn on the body first, and then fill both it and a part of the
+stem, proportionate to the length of the stem and the warmth of the season
+I fill it in with the best rectified _Spirit of Wine_ highly _ting'd_ with
+the lovely colour of _Cocheneel_, which I deepen the more by pouring some
+drops of common _Spirit of Urine_, which must not be too well rectified,
+because it will be apt to make the Liquor to curdle and stick in the small
+perforation of the stem. This Liquor I have upon tryal found the most
+tender of any spirituous Liquor, and those are much more sensibly affected
+with the variations of heat and cold then other more flegmatick and
+ponderous Liquors, and as capable of receiving a deep tincture, and keeping
+it, as any Liquor whatsoever; and (which makes it yet more acceptable) is
+not subject to be frozen by any cold yet known. When I have thus filled it,
+I can very easily in the forementioned flame of a Lamp seal and joyn on the
+head of it.
+
+Then, for graduating the stem, I fix that for the beginning of my division
+where the surface of the liquor in the stem remains when the ball is placed
+in common distilled water, that is so cold that it just begins to freeze
+and shoot into flakes; and that mark I fix at a convenient place of the
+stem, to make it capable of exhibiting very many degrees of cold, below
+that which is requisite to freeze water: the rest of my divisions, both
+above and below this (which I mark with a [0] or nought) I place according
+to the Degrees of _Expansion_, or _Contraction_ of the Liquor in proportion
+to the bulk it had when it indur'd the newly mention'd freezing cold. And
+this may be very easily and accurately enough done by this following way;
+Prepare a Cylindrical vessel of very thin plate Brass or Silver, ABCD of
+the figure Z; the Diameter AB of whose cavity let be about two inches, and
+the depth BC the same; let each end be cover'd with a flat and smooth plate
+of the same substance, closely soder'd on, and in the midst of the upper
+cover make a pretty large hole EF, about the bigness of a fifth part of the
+Diameter of the other; into this fasten very well with cement a straight
+and even Cylindrical pipe of Glass, EFGH, the Diameter of whose cavity let
+be exactly one tenth of the Diameter of the greater Cylinder. Let this pipe
+be mark'd at GH with a Diamant, so that G from E may be distant just two
+inches, or the same height with that of the cavity of the greater Cylinder,
+then divide the length EG exactly into 10 parts, so the capacity of the
+hollow of each of these divisions will be 1/1000 part of the capacity of
+the greater Cylinder. This vessel being thus prepared, the way of marking
+and graduating the _Thermometers_ may be very easily thus performed:
+
+Fill this Cylindrical vessel with the same liquor wherewith the
+_Thermometers_ are fill'd, then place both it and the _Thermometer_ you are
+to _graduate_, in water that is ready to be frozen, and bring the surface
+of the liquor in the _Thermometer_ to the first marke or [0]; then so
+proportion the liquor in the Cylindrical vessel, that the surface of it may
+just be at the lower end of the small glass-Cylinder; then very gently and
+gradually warm the water in which both the _Thermometer_ and this
+Cylindrical vessel stand, and as you perceive the ting'd liquor to rise in
+both stems, with the point of a Diamond give several marks on the stem of
+the _Thermometer_ at those places, which by comparing the expansion in both
+Stems, are found to correspond to the divisions of the cylindrical vessel,
+and having by this means marked some few of these divisions on the Stem, it
+will be very easie by these to mark all the rest of the Stem, and
+accordingly to assign to every division a proper character.
+
+A _Thermometer_, thus marked and prepared, will be the fittest Instrument
+to make a Standard of heat and cold that can be imagined. For being sealed
+up, it is not at all subject to variation or wasting, nor is it liable to
+be changed by the varying pressure of the Air, which all other kind of
+_Thermometers_ that are open to the Air are liable to. But to proceed.
+
+This property of Expansion with Heat, and Contraction with Cold, is not
+peculiar to Liquors only, but to all kind of solid Bodies also, especially
+Metals, which will more manifestly appear by this Experiment.
+
+Take the Barrel of a Stopcock of Brass, and let the Key, which is well
+fitted to it, be riveted into it, so that it may slip, and be easily turned
+round, then heat this Cock in the fire, and you will find the Key so
+swollen, that you will not be able to turn it round in the Barrel; but if
+it be suffered to cool again, as soon as it is cold it will be as movable,
+and as easie to be turned as before.
+
+This Quality is also very observable in _Lead_, _Tin_, _Silver_,
+_Antimony_, _Pitch_, _Rosin_, _Bees-wax_, _Butter_, and the like; all
+which, if after they be melted you suffer gently to cool, you shall find
+the parts of the upper Surface to subside and fall inwards, losing that
+plumpness and smoothness it had whilst in fusion. The like I have also
+observed in the cooling of _Glass of Antimony_, which does very neer
+approach the nature of Glass,
+
+But because these are all Examples taken from other materials then Glass,
+and argue only, that possibly there may be the like property also in Glass,
+not that really there is; we shall by three or four Experiments indeavour
+to manifest that also.
+
+And the First is an Observation that is very obvious even in these very
+drops, to wit, that they are all of them terminated with an unequal or
+irregular Surface, especially about the smaller part of the drop, and the
+whole length of the stem; as about D, and from thence to A, the whole
+Surface, which would have been round if the drop had cool'd leisurely, is,
+by being quenched hastily, very irregularly flatted and pitted; which I
+suppose proceeds partly from the Waters unequally cooling and pressing the
+parts of the drop, and partly from the self-contracting or subsiding
+quality of the substance of the Glass: For the vehemency of the heat of the
+drop causes such hidden motions and bubbles in the cold Water, that some
+parts of the Water bear more forcibly against one part then against
+another, and consequently do more suddenly cool those parts to which they
+are contiguous.
+
+A Second Argument may be drawn from the Experiment of cutting Glasses with
+a hot Iron. For in that Experiment the top of the Iron heats, and thereby
+rarifies the parts of the Glass that lie just before the crack, whence each
+of those agitated parts indeavouring to expand its self and get elbow-room,
+thrusts off all the rest of the contiguous parts, and consequently promotes
+the crack that was before begun.
+
+A Third Argument may be drawn from the way of producing a crack in a sound
+piece or plate of Glass, which is done two wayes, either First, by suddenly
+heating a piece of Glass in one place more then in another. And by this
+means _chymists_ usually cut off the necks of Glass-bodies, by two kinds of
+Instruments, either by a glowing hot round Iron-Ring, which just
+incompasses the place that is to be cut, or else by a _Sulphur'd_ Threed,
+which is often wound about the place where the separation is to be made,
+and then fired. Or Secondly, A Glass may be cracked by cooling it suddenly
+in any place with Water, or the like, after it has been all leisurely and
+gradually heated very hot. Both which _Phaenomena_ seem manifestly to
+proceed from the _expansion_ and contraction of the parts of the Glass,
+which is also made more probable by this circumstance which I have
+observed, that a piece of common window-glass being heated in the middle
+very suddenly with a live Coal or hot Iron, does usually at the first crack
+fall into pieces, whereas if the Plate has been gradually heated very hot,
+and a drop of cold Water and the like be put on the middle of it, it only
+flaws it, but does not break it asunder immediately.
+
+A Fourth Argument may be drawn from this Experiment; Take a Glass-pipe, and
+fit into a solid stick of Glass, so as it will but just be moved in it.
+Then by degrees heat them whilst they are one within another, and they will
+grow stiffer, but when they are again cold, they will be as easie to be
+turned as before. This Expansion of Glass is more manifest in this
+Experiment.
+
+Take a stick of Glass of a considerable length, and fit it so between the
+two ends or screws of a Lath, that it may but just easily turn, and that
+the very ends of it may be just toucht and susteined thereby; then applying
+the flame of the Candle to the middle of it, and heating it hot, you will
+presently find the Glass to stick very fast on those points, and not
+without much difficulty to be convertible on them, before that by removing
+the flame for a while from it, it be suffered to cool, and when you will
+find it as easie to be turned round as at the first.
+
+From all which Experiments it is very evident, that all those Bodies, and
+particularly Glass, suffers an Expansion by Heat, and that a very
+considerable one, whilst they are in a state of Fusion. For _Fluidity_, as
+I elsewhere mention, _being nothing but an effect of very strong and quick
+shaking motion, whereby the parts are, as it were, loosened from each
+other, and consequently leave an interjacent space or vacuity_; it follows,
+that all those shaken Particles must necessarily take up much more room
+then when they were at rest, and lay quietly upon each other. And this is
+further confirmed by a Pot of _boyling Alabaster_, which will manifestly
+rise a sixth or eighth part higher in the Pot, whilst it is boyling, then
+it will remain at, both before and after it be boyled. The reason of which
+odd _Phaenomenon_ (to hint it here only by the way) is this, that there is
+in the curious powder of Alabaster, and other calcining Stones, a certain
+watery substance, which is so fixt and included with the solid Particles,
+that till the heat be very considerable they will not fly away; but after
+the heat is increased to such a degree, they break out every way in
+vapours, and thereby so shake and loosen the small corpusles of the Powder
+from each other, that they become perfectly of the nature of a fluid body,
+and one may move a stick to and fro through it, and stir it as easily as
+water, and the vapours burst and break out in bubbles just as in boyling
+water, and the like; whereas, both before those watery parts are flying
+away, and after they are quite gone; that is, before and after it have done
+boyling, all those effects cease, and a stick is as difficultly moved to
+and fro in it as in sand, or the like. Which Explication I could easily
+prove, had I time; but this is not a fit place for it.
+
+To proceed therefore, I say, that the dropping of this expanded Body into
+cold Water, does make the parts of the Glass suffer a double contraction:
+The first is, of those parts which are neer the Surface of the Drop. For
+Cold, as I said before, contracting Bodies, that is, _by the abatement of
+the agitating faculty the parts falling neerer together_; the parts next
+adjoyning to the Water must needs lose much of their motion, and impart it
+to the Ambient-water (which the Ebullition and commotion of it manifests)
+and thereby become a solid and hard crust, whilst the innermost parts
+remain yet fluid and expanded; whence, as they grow cold also by degrees,
+their parts must necessarily be left at liberty to be condensed, but
+because of the hardness of the outward crust, the contraction cannot be
+admitted that way; but there being many very small, and before
+inconspicuous, bubbles in the substance of the Glass, upon the subsiding of
+the parts of the Glass, the agil substance contained in them has liberty of
+expanding it self a little, and thereby those bubbles grow much bigger,
+which is the second Contraction. And both these are confirmed from the
+appearance of the Drop it self: for as for the outward parts, we see,
+first, that it is irregular and shrunk, as it were, which is caused by the
+yielding a little of the hardened Skin to a Contraction, after the very
+outmost Surface is settled; and as for the internal parts, one may with
+ones naked Eye perceive abundance of very conspicuous bubbles, and with the
+_Microscope_ many more.
+
+The Consideration of which Particulars will easily make the Third Position
+probable, that is, that the parts of the drop will be of a very hard,
+though of a rarified Texture; for if the outward parts of the Drop, by
+reason of its hard crust, will indure very little Contraction, and the agil
+Particles, included in those bubbles, by the losing of their agitation, by
+the decrease of the Heat, lose also most part of their Spring and Expansive
+power; it follows (the withdrawing of the heat being very sudden) that the
+parts must be left in a very loose Texture, and by reason of the
+implication of the parts one about another, which from their sluggishnes
+and glutinousness I suppose to be much after the manner of the sticks in a
+Thorn-bush, or a Lock of Wool; it will follow, I say, that the parts will
+hold each other very strongly together, and indeavour to draw each other
+neerer together, and consequently their Texture must be very hard and
+stiff, but very much rarified.
+
+And this will make probable my next Position, That _the parts of the Glass
+are under a kind of tension or flexure, out of which they indeavour to
+extricate and free themselves_, and thereby all the parts draw towards the
+Center or middle, and would, if the outward parts would give way, as they
+do when the outward parts cool leisurely (as in baking of Glasses) contract
+the bulk of the drop into a much less compass. For since, as I proved
+before, the Internal parts of the drop, when fluid, were of a very rarified
+Texture, and, as it were, tos'd open like a Lock of Wool, and if they were
+suffered leisurely to cool, would be again prest, as it were, close
+together: And since that the heat, which kept them bended and open, is
+removed, and yet the parts not suffered to get as neer together as they
+naturally would; It follows, that the Particles remain under a kind of
+_tension_ and _flexure_, and consequently have an indeavour to free
+themselves from that _bending_ and _distension_, which they do, as soon as
+either the tip be broken, or as soon as by a leisurely heating and cooling,
+the parts are nealed into another posture.
+
+And this will make my next Position probable, that _the parts of the Glass
+drops are contignated together in the form of an Arch_, cannot any where
+yield or be drawn inwards, till by the removing of some one part of it (as
+it happens in the removing one of the stones of an Arch) the whole Fabrick
+is shatter'd, and falls to pieces, and each of the Springs is left at
+liberty, suddenly to extricate it self: for since I have made it probable,
+that the internal parts of the Glass have a contractive power inwards, and
+the external parts are incapable of such a Contraction, and the figure of
+it being spherical; it follows, that the superficial parts must bear
+against each other, and keep one another from being condens'd into a less
+room, in the same manner as the stones of an Arch conduce to the upholding
+each other in that Figure. And this is made more probable by another
+Experiment which was communicated to me by an excellent Person, whose
+extraordinary Abilities in all kind of Knowledg, especially in that of
+Natural things, and his generous Disposition in communicating, incouraged
+me to have recourse to him on many occasions. The Experiment was this:
+Small Glass-balls (about the bigness of that represented in the _Figure
+&._) would, upon rubbing or scratching the inward Surface, fly all
+insunder, with a pretty brisk noise; whereas neither before nor after the
+inner Surface had been thus scratcht, did there appear any flaw or crack.
+And putting the pieces of one of those broken ones together again, the
+flaws appeared much after the manner of the black lines on the Figure, _&._
+These Balls were small, but exceeding thick bubbles of Glass, which being
+crack'd off from the _Puntilion_ whilst very hot, and so suffered to cool
+without nealing them in the Oven over the Furnace, do thereby (being made
+of white Glass, which cools much quicker then green Glass, and is thereby
+made much brittler) acquire a very _porous_ and very brittle _texture_: so
+that if with the point of a Needle or Bodkin, the inside of any of them be
+rubbed prety hard, and then laid on a Table, it will, within a very little
+while, break into many pieces with a brisk noise, and throw the parts above
+a span asunder on the Table: Now though the pieces are not so small as
+those of a _fulminating_ drop, yet they as plainly shew, that the outward
+parts of the Glass have a great _Conatus_ to fly asunder, were they not
+held together by the _tenacity_ of the parts of the inward Surface: for we
+see as soon as those parts are crazed by hard rubbing, and thereby their
+tenacity spoiled, the springiness of the more outward parts quickly makes a
+divulsion, and the broken pieces will, if the concave Surface of them be
+further scratcht with a Diamond, fly again into smaller pieces.
+
+From which preceding considerations it will follow Sixthly, That the sudden
+flying asunder of the parts as soon as this Arch is any where disordered or
+broken, proceeds from the springing of the parts; which, indeavouring to
+_extricate_ themselves as soon as they get the liberty, they perform it
+with such a quickness, that they throw one another away with very great
+violence: for the Particles that compose the Crust have a _Conatus_ to lye
+further from one another, and therefore as soon as the external parts are
+loosened they dart themselves outward with great violence, just as so many
+Springs would do, if they were detained and fastened to the body, as soon
+as they should be suddenly loosened; and the internal parts drawing inward,
+they contract so violently; that they rebound back again and fly into
+multitude of small shivers or sands. Now though they appear not, either to
+the naked Eye, or the _Microscope_, yet I am very apt to think there may be
+abundance of small flaws or cracks, which, by reason the strong reflecting
+Air is not got between the _contiguous_ parts, appear not. And that this
+may be so, I argue from this, that I have very often been able to make a
+crack or flaw, in some convenient pieces of Glass, to appear and disappear
+at pleasure, according as by pressing together, or pulling asunder the
+contiguous parts, I excluded or admitted the strong reflecting Air between
+the parts: And it is very probable, that there may be some Body, that is
+either very rarified Air, or something _analogous_ to it, which fills the
+bubbles of these drops; which I argue, first, from the roundness of them,
+and next, from the vivid reflection of Light which they exhibite: Now
+though I doubt not, but that the Air in them is very much rarified, yet
+that there is some in them, to such as well consider this Experiment of the
+disappearing of a crack upon the _extruding_ of the Air, I suppose it will
+seem more then probable.
+
+The Seventh and last therefore that I shall prove, is, _That the gradual
+heating and cooling of these so extended bodies does reduce the parts of
+the Glass to a looser and softer temper_. And this I found by heating them,
+and keeping them for a prety while very red hot in a fire; for thereby I
+found them to grow a little lighter, and the small Stems to be very easily
+broken and snapt any where, without at all making the drop fly; whereas
+before they were so exceeding hard, that they could not be broken without
+much difficulty; and upon their breaking the whole drop would fly in pieces
+with very great violence. The Reason of which last seems to be, that the
+leisurely heating and cooling of the parts does not only wast some part of
+the Glass it self, but ranges all the parts into a better order, and gives
+each Particle an opportunity of _relaxing_ its self, and consequently
+neither will the parts hold so strongly together as before, nor be so
+difficult to be broken: The parts now more easily yielding, nor will the
+other parts fly in pieces, because the parts have no bended Springs. The
+_relaxation_ also in the temper of hardned Steel, and hammered Metals, by
+nealing them in the fire, seems to proceed from much the same cause. For
+both by quenching suddenly such Metals as have _vitrifed_ parts
+interspers'd, as Steel has, and by hammering of other kinds that do not so
+much abound with them, as Silver Brass, &c. the parts are put into and
+detained in a bended posture, which by the agitation of Heat are shaken,
+and loosened, and suffered to unbend themselves.
+
+       *       *       *       *       *
+
+
+Observ. VIII. _Of the fiery Sparks struck from a Flint or Steel._
+
+It is a very common Experiment, by striking with a Flint against a Steel,
+to make certain fiery and shining Sparks to fly out from between those two
+compressing Bodies. About eight years since, upon casually reading the
+Explication of this odd _Phaenomenon_, by the most Ingenious _Des Cartes_,
+I had a great desire to be satisfied, what that Substance was that gave
+such a shining and bright Light: And to that end I spread a sheet of white
+Paper, and on it, observing the place where several of these Sparks seemed
+to vanish, I found certain very small, black, but glittering Spots of a
+movable Substance, each of which examining with my _Microscope_, I found to
+be a small round _Globule_; some of which, as they looked prety small, so
+did they from their Surface yield a very bright and strong reflection on
+that side which was next the Light; and each look'd almost like a prety
+bright Iron-Ball, whose Surface was prety regular, such as is represented
+by the Figure A. In this I could perceive the Image of the Window prety
+well, or of a Stick, which I moved up and down between the Light and it.
+Others I found, which were, as to the bulk of the Ball, prety regularly
+round, but the Surface of them, as it was not very smooth, but rough, and
+more irregular, so was the reflection from it more faint and confused. Such
+were the Surfaces of B. C. D. and E. Some of these I found cleft or
+cracked, as C, others quite broken in two and hollow, as D. which seemed to
+be half the hollow shell of a Granado, broken irregularly in pieces.
+Several others I found of other shapes; but that which is represented by E,
+I observed to be a very big Spark of fire, which went out upon one side of
+the Flint that I struck fire withall, to which it stuck by the root F, at
+the end of which small Stem was fastened-on a _Hemisphere_, or half a
+hollow Ball, with the mouth of it open from the stemwards, so that it
+looked much like a Funnel, or an old fashioned Bowl without a foot. This
+night, making many tryals and observations of this Experiment, I met, among
+a multitude of the Globular ones which I had observed, a couple of
+Instances, which are very remarkable to the confirmation of my
+_Hypothesis_.
+
+And the First was of a pretty big Ball fastened on to the end of a small
+sliver of Iron, which _Compositum_ seemed to be nothing else but a long
+thin chip of Iron, one of whose ends was melted into a small round Globul;
+the other end remaining unmelted and irregular, and perfectly Iron.
+
+The Second Instance was not less remarkable then the First; for I found,
+when a Spark went out, nothing but a very small thin long sliver of Iron or
+Steel, unmelted at either end. So that it seems, that some of these Sparks
+are the slivers or chips of the Iron _vitrified_, Others are only the
+slivers melted into Balls without vitrification, And the third kind are
+only small slivers of the Iron, made red-hot with the violence of the
+stroke given on the Steel by the Flint.
+
+He that shall diligently examine the _Phaenomena_ of this Experiment, will,
+I doubt not, find cause to believe, that the reason I have heretofore given
+of it, is the true and genuine cause of it, namely, That _the Spark,
+appearing so bright in the falling, is nothing else but a small piece of
+the Steel or Flint, but most commonly of the Steel, which by the violence
+of the stroke is at the same time sever'd and heat red-hot, and that
+sometimes to such a degree, as to make it melt together into a small
+Globule of Steel; and sometimes also is that heat so very intense, as
+further to melt it and vitrifie it; but many times the heat is so gentle,
+as to be able to make the sliver only red hot, which notwithstanding
+falling upon the tinder_ (that is only a very curious small Coal made of
+the small threads of Linnen burnt to coals and char'd) _it easily sets it
+on fire_. Nor will any part of this _Hypothesis_ seem strange to him that
+considers, First, that either hammering, or filing or otherwise violently
+rubbing of Steel, will presently make it so hot as to be able to burn ones
+fingers. Next, that the whole force of the stroke is exerted upon that
+small part where the Flint and Steel first touch: For the Bodies being each
+of them so very hard, the puls cannot be far communicated, that is, the
+parts of each can yield but very little, and therefore the violence of the
+concussion will be _exerted_ on that piece of Steel which is cut off by the
+Flint. Thirdly, that the filings or small parts of Steel are very apt, as
+it were, to take fire, and are presently red hot, that is, there seems to
+be a very _combustible sulphureous_ Body in Iron or Steel, which the Air
+very readily preys upon, as soon as the body is a little violently heated.
+
+And this is obvious in the filings of Steel or Iron cast through the flame
+of a Candle; for even by that sudden _transitus_ of the small chips of
+Iron, they are heat red hot, and that _combustible sulphureous_ Body is
+presently prey'd upon and devoured by the _aereal_ incompassing
+_Menstruum_, whose office in this Particular I have shewn in the
+Explication of Charcole.
+
+And in prosecution of this Experiment, having taken the filings of Iron and
+Steel, and with the point of a Knife cast them through the flame of a
+Candle, I observed where some conspicuous shining Particles fell, and
+looking on them with my _Microscope_, I found them to be nothing else but
+such round Globules, as I formerly found the Sparks struck from the Steel
+by a stroke to be, only a little bigger; and shaking together all the
+filings that had fallen upon the sheet of Paper underneath and observing
+them with the _Microscope_, I found a great number of small Globules, such
+as the former, though there were also many of the parts that had remained
+untoucht and rough filings or chips of Iron. So that, it seems, Iron does
+contain a very _combustible sulphureous_ Body, which is, in all likelihood,
+one of the causes of this _Phaenomenon_, and which may be perhaps very much
+concerned in the business of its hardening and tempering: of which somewhat
+it said in the Description of _Muscovy-glass_.
+
+So that, these things considered, we need not trouble our selves to find
+out what kind of Pores they are, both in the Flint and Steel, that contain
+the _Atoms of fire_, nor how those _Atoms_ come to be hindred from running
+all out, when a dore or passage in their Pores is made by the concussion:
+nor need we trouble our selves to examine by what _Prometheus_ the Element
+of Fire comes to be fetcht down from above the Regions of the Air, in what
+Cells or Boxes it is kept, and what _Epimetheus_ lets it go: Nor to
+consider what it is that causes so great a conflux of the atomical
+Particles of Fire, which are said to fly to a flaming Body, like Vultures
+or Eagles to a putrifying Carcass, and there to make a very great pudder.
+Since we have nothing more difficult in this _Hypothesis_ to conceive,
+first, as to the kindling of Tinder, then how a large Iron-bullet, let fall
+red or glowing hot upon a heap of Small-coal, should set fire to those that
+are next to it first: Nor secondly, is this last more difficult to be
+explicated, then that a Body, as Silver for Instance, put into a weak
+_Menstruum_, as unrectified _Aqua fortis_ should, when it is put in a great
+heat, be there dissolved by it, and not before; which _Hypothesis_ is more
+largely explicated in the Description of Charcoal. To conclude, we see by
+this Instance, how much Experiments may conduce to the regulating of
+_Philosophical notions_. For if the most Acute _Des Cartes_ had applied
+himself experimentally to have examined what substance it was that caused
+that shining of the falling Sparks struck from a Flint and a Steel, he
+would certainly have a little altered his _Hypothesis_, and we should have
+found, that his Ingenious Principles would have admitted a very plausible
+Explication of this _Phaenomenon_; whereas by not examining so far as he
+might, he has set down an Explication which Experiment do's contradict.
+
+But before I leave this Description, I must not forget to take notice of
+the Globular form into which each of these is most curiously formed. And
+this _Phaenomenon_, as I have elsewhere more largely shewn, proceeds from a
+propriety which belongs to all kinds of fluid Bodies more or less, and is
+caused by the Incongruity of the Ambient and included Fluid, which so acts
+and modulates each other, that they acquire, as neer as is possible, a
+_spherical_ or _globular_ form, which propriety and several of the
+_Phaenomena_ that proceed from it, I have more fully explicated in the
+sixth Observation.
+
+One Experiment, which does very much illustrate my present Explication, and
+is in it self exceeding pretty, I must not pass by: And that is a way of
+making small _Globules_ or _Balls_ of Lead, or Tin, as small almost as
+these of Iron or Steel, and that exceeding easily and quickly, by turning
+the filings or chips of those Metals also into perfectly round _Globules_.
+The way, in short, as I received it from the _Learned Physitian Doctor_
+I.G. is this;
+
+Reduce the Metal you would thus shape, into exceeding fine filings, the
+finer the filings are, the finer will the Balls be: _Stratifie_ these
+filings with the fine and well dryed powder of quick Lime in a _Crucible_
+proportioned to the quantity you intend to make: When you have thus filled
+your _Crucible_, by continual _stratifications_ of the filings and powder,
+so that, as neer as may be, no one of the filings may touch another, place
+the _Crucible_ in a _gradual fire_, and by degrees let it be brought to a
+heat big enough to make all the filings, that are mixt with the quick Lime,
+to melt, and no more; for if the fire be too hot, many of these filings
+will joyn and run together; whereas if the heat be proportioned, upon
+washing the Lime-dust in fair Water, all those small filings of the Metal
+will subside to the bottom in a most curious powder, consisting all of
+exactly round _Globules_, which, if it be very fine, is very excellent to
+make Hour-glasses of.
+
+Now though quick Lime be the powder that this direction makes choice of,
+yet I doubt not, but that there may be much more convenient ones found out,
+one of which I have made tryal of, and found very effectual; and were it
+not for discovering, by the mentioning of it, another Secret, which I am
+not free to impart, I should have here inserted it.
+
+       *       *       *       *       *
+
+
+Observ. IX. _Of the Colours observable in Muscovy Glass, and other thin
+Bodies_.
+
+Moscovy-glass, or _Lapis specularis_, is a Body that seems to have as many
+Curiosities in its Fabrick as any common Mineral I have met with: for
+first, It is transparent to a great thickness: Next, it is compounded of an
+infinite number of thin flakes joyned or generated one upon another so
+close & smooth, as with many hundreds of them to make one smooth and thin
+Plate of a transparent flexible substance, which with care and diligence
+may be flit into pieces so exceedingly thin as to be hardly perceivable by
+the eye, and yet even those, which I have thought the thinnest, I have with
+a good _Microscope_ found to be made up of many other Plates, yet thinner;
+and it is probable, that, were our _Microscopes_ much better, we might much
+further discover its divisibility. Nor are these flakes only regular as to
+the smoothness of their Surfaces, but thirdly, In many Plates they may be
+perceived to be terminated naturally with edges of the figure of a
+_Rhomboeid_. This Figure is much more conspicuous in our English talk, much
+whereof is found in the Lead Mines, and is commonly called _Spar_, and
+_Kauck_, which is of the same kind of substance with the _Selenitis_, but
+is seldom found in so large flakes as that is, nor is it altogether so
+tuff, but is much more clear and transparent, and much more curiously
+shaped, and yet may be cleft and flak'd like the other _Selenitis_. But
+fourthly, this stone has a property, which in respect of the _Microscope_,
+is more notable, and that is, that it exhibits several appearances of
+Colours, both to the naked Eye, but much more conspicuously to the
+_Microscope_; for the exhibiting of which, I took a piece of
+_Muscovy-glass_, and splitting or cleaving it into thin Plates, I found
+that up and down in several parts of them I could plainly perceive several
+white specks or flaws, and others diversly coloured with all the Colours of
+the _Rainbow_; and with the _Microscope_ I could perceive, that these
+Colours were ranged in rings that incompassed the white speck or flaw, and
+were round or irregular, according to the shape of the spot which they
+terminated; and the position of Colours, in respect of one another, was the
+very same as in the _Rainbow_. The consecution of those Colours from the
+middle of the spot outward being Blew, Purple, Scarlet, Yellow, Green;
+Blew, Purple, Scarlet, and so onwards, sometimes half a score times
+repeated, that is, there appeared six, seven, eight, nine or ten several
+coloured rings or lines, each incircling the other, in the same manner as I
+have often seen a very _vivid Rainbow_ to have four or five several Rings
+of Colours, that is, accounting all the Gradations between Red and Blew for
+one: But the order of the Colours in these Rings was quite contrary to the
+primary or innermost _Rainbow_, and the same with those of the secondary or
+outermost Rainbow; these coloured Lines or _Irises_, as I may so call them,
+were some of them much brighter then others, and some of them also very
+much broader, they being some of them ten, twenty, nay, I believe, neer a
+hundred times broader then others; and those usually were broadest which
+were neerest the center or middle of the flaw. And oftentimes I found, that
+these Colours reacht to the very middle of the flaw, and then there
+appeared in the middle a very large spot, for the most part, all of one
+colour, which was very vivid, and all the other Colours incompassing it,
+gradually ascending, and growing narrower towards the edges, keeping the
+same order, as in the _secundary Rainbow_, that is, if the middle were
+Blew, the next incompassing it would be a Purple, the third a Red, the
+fourth a Yellow, &c. as above; if the middle were a Red, the next without
+it would be a Yellow, the third a Green, the fourth a Blew, and so onward.
+And this order it alwayes kept whatsoever were the middle Colour.
+
+There was further observable in several other parts of this Body, many
+Lines or Threads, each of them of some one peculiar Colour, and those so
+exceedingly bright and vivid, that it afforded a very pleasant object
+through the _Microscope_. Some of these _threads_ I have observed also to
+be pieced or made up of several short lengths of differently coloured
+_ends_ (as I may so call them) as a line appearing about two inches long
+through the _Microscope_, has been compounded of about half an inch of a
+Peach colour, 1/8 of a lovely Grass-green, 3/4 of an inch more of a bright
+Scarlet, and the rest of the line of a Watchet blew. Others of them were
+much otherwise coloured; the variety being almost infinite. Another thing
+which is very observable, is, that if you find any place where the colours
+are very broad and conspicuous to the naked eye, you may, by pressing that
+place with your finger, make the colours change places, and go from one
+part to another.
+
+There is one _Phaenomenon_ more, which may, if care be used, exhibit to the
+beholder, as it has divers times to me, an exceeding pleasant, and not less
+instructive Spectacle; And that is, if curiosity and diligence be used, you
+may so split this admirable Substance, that you may have pretty large
+Plates (in companion of those smaller ones which you may observe in the
+Rings) that are perhaps an 1/8 or a 1/6 part of an inch over, each of them
+appearing through the _Microscope_ most curiously, intirely, and uniformly
+adorned with some one vivid colour: this, if examined with the
+_Microscope_, may be plainly perceived to be in all parts of it equally
+thick. Two, three, or more of these lying one upon another, exhibit
+oftentimes curious compounded colours, which produce such a _Compositum_,
+as one would scarce imagine should be the result of such _ingredients_: As
+perhaps a _faint yellow_ and a _blew_ may produce a very _deep purple_. But
+when anon we come to the more strict examination of these _Phaenomena_, and
+to inquire into the causes and reasons of these productions, we shall, I
+hope, make it more conceivable how they are produced, and shew them to be
+no other then the natural and necessary effects arising from the peculiar
+union of concurrent causes.
+
+These _Phaenomena_, being so various, and so truly admirable, it will
+certainly be very well worth our inquiry, to examine the causes and reasons
+of them, and to consider, whether from these causes demonstratively
+evidenced, may not be deduced the true causes of the production of all kind
+of Colours. And I the rather now do it, instead of an Appendix or
+Digression to this History, then upon the occasion of examining the Colours
+in Peacocks, or other Feathers, because this Subject, as it does afford
+more variety of particular Colours, so does it afford much better wayes of
+examining each circumstance. And this will be made manifest to him that
+considers, first, that this laminated body is more simple and regular then
+the parts of Peacocks feathers, this consisting only of an indefinite
+number of plain and smooth Plates, heaped up, or _incumbent_ on each other.
+Next, that the parts of this body are much more manageable, to be divided
+or joyned, then the parts of a Peacocks feather, or any other substance
+that I know. And thirdly, because that in this we are able from a
+colourless body to produce several coloured bodies, affording all the
+variety of Colours imaginable: And several others, which the subsequent
+Inquiry will make manifest.
+
+To begin therefore, it is manifest from several circumstances, that the
+material cause of the _apparition_ of these several Colours, is some
+_Lamina_ or Plate of a transparent or pellucid body of a thickness very
+determinate and proportioned according to the greater or less refractive
+power of the _pellucid_ body. And that this is so, abundance of Instances
+and particular Circumstances will make manifest.
+
+As _first_, if you take any small piece of the _Muscovy-glass_, and with a
+Needle, or some other convenient Instrument, cleave it oftentimes into
+thinner and thinner _Laminae_, you shall find, that till you come to a
+determinate thinness of them, they shall all appear transparent and
+colourless, but if you continue to split and divide them further, you shall
+find at last, that each Plate, after it comes to such a determinate
+thickness, shall appear most lovely ting'd or imbued with a determinate
+colour. If _further_, by any means you so flaw a pretty thick piece, that
+one part does begin to cleave a little from the other, and between those
+two there be by any means gotten some pellucid _medium_, those _laminated_
+pellucid bodies that fill that space, shall exhibit several Rainbows or
+coloured Lines, the colours of which will be disposed and ranged according
+to the various thicknesses of the several parts of that Plate. That this is
+so, is yet _further_ confirmed by this Experiment.
+
+Take two small pieces of ground and polisht Looking-glass-plate, each about
+the bigness of a shilling, take these two dry, and with your fore-fingers
+and thumbs press them very hard and close together, and you shall find,
+that when they approach each other very near, there will appear several
+_Irises_ or coloured Lines, in the same manner almost as in the
+_Muscovy-glass_; and you may very easily change any of the Colours of any
+part of the interposed body, by pressing the Plates closer and harder
+together, or leaving them more lax; that is, a part which appeared coloured
+with a red, may be presently ting'd with a yellow, blew, green, purple, or
+the like, by altering the appropinquation of the terminating Plates. Now
+that air is not necessary to be the interposed body, but that any other
+transparent fluid will do much the same, may be tryed by wetting those
+approximated Surfaces with Water, or any other transparent Liquor, and
+proceeding with it in the same manner as you did with the Air; and you will
+find much the like effect, only with this difference, that those comprest
+bodies, which differ most, in their refractive quality, from the
+compressing bodies, exhibit the most strong and vivid tinctures. Nor is it
+necessary, that this _laminated_ and _ting'd_ body should be of a fluid
+substance, any other substance, provided it be thin enough and transparent,
+doing the same thing: this the _Laminae_ of our _Muscovy-glass_ hint; but
+it may be confirm'd by multitudes of other Instances.
+
+And first, we shall find, that even Glass it self may, by the help of a
+Lamp, be blown thin enough to produce these _Phaenomena_ of Colours: which
+_Phaenomena_ accidentally happening, as I have been attempting to frame
+small Glasses with a Lamp, did not a little surprize me at first, having
+never heard or seen any thing of it before; though afterwards comparing it
+with the _Phaenomena_, I had often observed in those Bubbles which Children
+use to make with Soap-water, I did the less wonder; especially when upon
+Experiment I found, I was able to produce the same _Phaenomena_ in thin
+Bubbles made with any other transparent Substance. Thus have I produced
+them with Bubbles of _Pitch_, _Rosin_, _Colophony_, _Turpentine_,
+_Solutions_ of several _Gums_, as _Gum-Arabick_ in water; any _glutinous_
+Liquor, as _Wort_, _Wine_, _Spirit of Wine_, _Oyl of Turpentine_, _Glare of
+Snails,_ &c.
+
+It would be needless to enumerate the several Instances, these being enough
+to shew the generality or universality of this propriety. Only I must not
+omit, that we have instances also of this kind even in metalline Bodies and
+animal; for those several Colours which are observed to follow each other
+upon the polisht surface of hardned Steel, when it is by a sufficient
+degree of heat gradually tempered or softened, are produced, from nothing
+else but a certain thin _Lamina_ of a _vitrum_ or _vitrified_ part of the
+Metal, which by that degree of heat, and the concurring action of the
+ambient Air, is driven out and fixed on the surface of the Steel.
+
+And this hints to me a very probable (at least, if not the true) cause of
+the hardning and tempering of Steel, which has not, I think, been yet
+given, nor, that I know of been so much as thought of by any. And that is
+this, that the hardness of it arises from a greater proportion of a
+vitrified Substance interspersed through the pores of the Steel. And that
+the tempering or softning of it arises from the proportionate or smaller
+parcels of it left within those pores. This will seem the more probable, if
+we consider these Particulars.
+
+First, That the pure parts of Metals are of themselves very _flexible_ and
+_tuff_; that is, will indure bending and hammering, and yet retain their
+continuity.
+
+Next, That the Parts of all vitrified Substances, as all kinds of Glass,
+the _Scoria_ of Metals, &c. are very hard, and also very brittle, being
+neither _flexible_ nor _malleable_, but may by hammering or beating be
+broken into small parts or powders.
+
+Thirdly, That all Metals (excepting Gold and Silver, which do not so much
+with the bare fire, unless assisted by other saline Bodies) do more or less
+_vitrifie_ by the strength of fire, that is, are corroded by a saline
+Substance, which I elsewhere shew to be the true cause of fire; and are
+thereby, as by several other _Menstruums_ converted into _Scoria_; And this
+is called, _calcining_ of them, by Chimists. Thus Iron and Copper by
+heating and quenching do turn all of them by degrees into _Scoria_, which
+are evidently _vitrified_ Substances, and unite with Glass, and are easily
+_fusible_; and when cold, very hard, and very brittle.
+
+Fourthly, That most kind of _Vitrifications_ or _Calcinations_ are made by
+Salts, uniting and incorporating with the metalline Particles. Nor do I
+know any one _calcination_ wherein a _Saline_ body may not, with very great
+probability, be said to be an agent or coadjutor.
+
+Fifthly, That Iron is converted into Steel by means of the incorporation of
+certain salts, with which it is kept a certain time in the fire.
+
+Sixthly, That any Iron may, in a very little time, be _case hardned_, as
+the Trades-men call it, by casing the iron to be hardned with clay, and
+putting between the clay and iron a good quantity of a mixture of _Urine_,
+_Soot_, _Sea-salt_, and _Horses hoofs_ (all which contein great quantities
+of Saline bodies) and then putting the case into a good strong fire, and
+keeping it in a considerable degree of heat for a good while, and
+afterwards heating, and quenching or cooling it suddenly in cold water.
+
+Seventhly, That all kind of vitrify'd substances, by being suddenly cool'd,
+become very hard and brittle. And thence arises the pretty _Phaenomena_ of
+the Glass Drops, which I have already further explained in its own place.
+
+Eighthly, That those metals which are not so apt to vitrifie, do not
+acquire any hardness by quenching in water, as Silver, Gold, &c.
+
+These considerations premis'd, will, I suppose, make way for the more easie
+reception of this following Explication of the _Phaenomena_ of hardned and
+temper'd Steel. That Steel is a substance made out of Iron, by means of a
+certain proportionate _Vitrification_ of several parts, which are so
+curiously and proportionately mixt with the more tough and unalter'd parts
+of the Iron, that when by the great heat of the fire this vitrify'd
+substance is melted, and consequently rarify'd, and thereby the pores of
+the Iron are more open, if then by means of dipping it in cold water it be
+suddenly cold, and the parts hardned, that is, stay'd in that same degree
+of _Expansion_ they were in when hot, the parts become very hard and
+brittle, and that upon the same account almost as small parcels of glass
+quenched in water grow brittle, which we have already explicated. If after
+this the piece of Steel be held in some convenient heat, till by degrees
+certain colours appear upon the surface of the brightned metal, the very
+hard and brittle tone of the metal, by degrees relaxes and becomes much
+more tough and soft; namely, the action of the heat does by degrees loosen
+the parts of the Steel that were before streached or set _atilt_ as it
+were, and stayed open by each other, whereby they become relaxed and set at
+liberty, whence some of the more brittle interjacent parts are thrust out
+and melted into a thin skin on the surface of the Steel, which from no
+colour increases to a deep Purple, and so onward by these _gradations_ or
+consecutions, _White, Yellow, Orange, Minium, Scarlet, Purple, Blew,
+Watchet,_ &c. and the parts within are more conveniently, and
+proportionately mixt; and so they gradually subside into a texture which is
+much better proportion'd and closer joyn'd, whence that rigidnesse of parts
+ceases, and the parts begin to acquire their former _ductilness_.
+
+Now, that 'tis nothing but the vitrify'd metal that sticks upon the surface
+of the colour'd body, is evident from this, that if by any means it be
+scraped and rubb'd off, the metal underneath it is white and clear; and if
+it be kept longer in the fire, so as to increase to a considerable
+thickness, it may, by blows, be beaten off in flakes. This is further
+confirm'd by this observable, that that Iron or Steel will keep longer from
+rusting which is covered with this vitrify'd case: Thus also Lead will, by
+degrees, be all turn'd into a litharge; for that colour which covers the
+top being scum'd or shov'd aside, appears to be nothing else but a litharge
+or vitrify'd Lead.
+
+This is observable also in some sort, on Brass, Copper, Silver, Gold, Tin,
+but is most conspicuous in Lead: all those Colours that cover the surface
+of the Metal being nothing else, but a very thin vitrifi'd part of the
+heated Metal.
+
+The other Instance we have, is in Animal bodies, as in Pearls, Mother of
+Pearl-shels, Oyster-shels, and almost all other kinds of stony shels
+whatsoever. This have I also sometimes with pleasure observ'd even in
+Muscles and Tendons. Further, if you take any glutinous substance and run
+it exceedingly thin upon the surface of a smooth glass or a polisht
+metaline body, you shall find the like effects produced: and in general,
+wheresoever you meet with a transparent body thin enough, that is
+terminated by reflecting bodies of differing refractions from it, there
+will be a production of these pleasing and lovely colours.
+
+Nor is it necessary, that the two _terminating_ Bodies should be both of
+the same kind, as may appear by the _vitrified Laminae_ on _Steel_, _Lead_,
+and other Metals, one surface of which _Laminae_ is contiguous to the
+surface of the Metal, the other to that of the Air.
+
+Nor is it necessary, that these colour'd _Laminae_ should be of an even
+thickness, that is, should have their edges and middles of equal thickness,
+as in a Looking-glass-plate, which circumstance is only requisite to make
+the Plate appear all of the same colour; but they may resemble a _Lens_,
+that is, have their middles thicker then their edges; or else a _double
+concave_, that is, be thinner in the middle then at the edges; in both
+which cases there will be various coloured rings or lines, with differing
+consecutions or orders of Colours; the order of the first from the middle
+outwards being Red, Yellow, Green, Blew, &c. And the latter quite contrary.
+
+But further, it is altogether necessary, that the Plate, in the places
+where the Colours appear, should be of a determinate thickness: First, It
+must not be more then such a thickness, for when the Plate is increased to
+such a thickness, the Colours cease; and besides, I have seen in a thin
+piece of _Muscovy-glass_, where the two ends of two Plates, which appearing
+both single, exhibited two distinct and differing Colours; but in that
+place where they were united, and constituted one double Plate (as I may
+call it) they appeared transparent and colourless. Nor, Secondly, may the
+Plates be _thinner_ then such a determinate _cize_; for we alwayes find,
+that the very outmost Rim of these flaws is terminated in a white and
+colourless Ring.
+
+Further, in this Production of Colours there is no need of a determinate
+Light of such a bigness and no more, nor of a determinate position of that
+Light, that it should be on this side, and not on that side; nor of a
+terminating shadow, as in the Prisme, and Rainbow, or Water-ball: for we
+find, that the Light in the open Air, either in or out of the Sun-beams,
+and within a Room, either from one or many Windows, produces much the same
+effect: only where the Light is brightest, there the Colours are most
+_vivid_. So does the light of a Candle, collected by a Glass-ball. And
+further, it is all one whatever side of the coloured Rings be towards the
+light; for the whole Ring keeps its proper Colours from the middle outwards
+in the same order as I before related, without varying at all, upon
+changing the position of the light.
+
+But above all it is most observable, that here are all kind of Colours
+generated in a _pellucid_ body, where there is properly no such refraction
+as _Des Cartes_ supposes his _Globules_ to acquire a _vertuity_ by: For in
+the plain and even Plates it is manifest, that the second refraction
+(according to _Des Cartes_ his Principles in the _fifth section of the
+eighth Chapter of his Meteors_) does regulate and restore the supposed
+_turbinated Globules_ unto their former uniform motion. This Experiment
+therefore will prove such a one as our _thrice excellent Verulam_ calls
+_Experimentum Crucis_, serving as a Guide or Land-mark, by which to direct
+our course in the search after the true cause of Colours. Affording us this
+particular negative Information, that for the production of Colours there
+is not necessary either a great refraction, as in the Prisme; nor Secondly,
+a determination of Light and shadow, such as is both in the Prisme and
+Glass-ball. Now that we may see likewise what affirmative and positive
+Instruction it yields, it will be necessary, to examine it a little more
+particularly and strictly; which that we may the better do, it will be
+requisite to premise somewhat in general concerning the nature of Light and
+Refraction.
+
+And first for Light it seems very manifest, that there is no luminous Body
+but has the parts of it in motion more or less.
+
+First, That all kind of _fiery burning Bodies_ have their parts in motion,
+I think, will be very easily granted me. That the _spark_ struck from a
+Flint and Steel is in a rapid agitation, I have elsewhere made probable.
+And that the Parts of _rotten Wood_, _rotten Fish_ and the like, are also
+in motion, I think, will as easily be conceded by those, who consider, that
+those parts never begin to shine till the Bodies be in a state of
+putrefaction; and that is now generally granted by all, to be caused by the
+motion of the parts of putrifying bodies. That the _Bononian stone_ shines
+no longer then it is either warmed by the Sun-beams, or by the flame of a
+Fire or of a Candle, is the general report of those that write of it, and
+of others that have seen it. And that heat argues a motion of the internal
+parts is (as I said before) generally granted.
+
+But there is one Instance more, which was first shewn to the _Royal
+Society_ by Mr. _Clayton_ a worthy Member thereof, which does make this
+Assertion more evident then all the rest: And that is, That a _Diamond_
+being _rub'd_, _struck_ or _heated_ in the dark, shines for a pretty while
+after, so long as that motion, which is imparted by any of those Agents,
+remains (in the same manner as a Glass, rubb'd, struck, or (by a means
+which I shall elsewhere mention) heated, yields a sound which lasts as long
+as the vibrating motion of that _sonorous_ body) several Experiments made
+on which Stone, are since published in a Discourse of Colours, by the truly
+honourable Mr. _Boyle_. What may be said of those _Ignes fatui_ that appear
+in the night, I cannot so well affirm, having never had the opportunity to
+examine them my self, nor to be inform'd by any others that had observ'd
+them: And the relations of them in Authors are so imperfect, that nothing
+can be built on them. But I hope I shall be able in another place to make
+it at least very probable, that there is even in those also a Motion which
+causes this effect. That the shining of _Sea-water_ proceeds from the same
+cause, may be argued from this, That it shines not till either it be beaten
+against a Rock, or be some other wayes broken or agitated by Storms, or
+Oars, or other _percussing_ bodies. And that the Animal _Energyes_ or
+Spirituous _agil_ parts are very active in _Cats eyes_ when they shine,
+seems evident enough, because their eyes never shine but when they look
+very intensly either to find their prey, or being hunted in a dark room,
+when they seek after their adversary, or to find a way to escape. And the
+like may be said of the shining _Bellies of Gloworms_; since 'tis evident
+they can at pleasure either increase or extinguish that Radiation.
+
+It would be somewhat too long a work for this place _Zetetically_ to
+examine, and positively to prove, what particular kind of motion it is that
+must be the efficient of Light; for though it be a motion, yet 'tis not
+every motion that produces it, since we find there are many bodies very
+violently mov'd, which yet afford not such an effect; and there are other
+bodies, which to our other senses, seem not mov'd so much, which yet shine.
+Thus Water and quick-silver, and most other liquors heated, shine not; and
+several hard bodies, as Iron, Silver, Brass, Copper, Wood, &c. though very
+often struck with a hammer, shine not presently, though they will all of
+them grow exceeding hot; whereas rotten Wood, rotten Fish, Sea water,
+Gloworms, &c. have nothing of tangible heat in them, and yet (where there
+is no stronger light to affect the Sensory) they shine some of them so
+Vividly, that one may make a shift to read by them.
+
+It would be too long, I say, here to insert the discursive progress by
+which I inquir'd after the proprieties of the motion of Light, and
+therefore I shall only add the result.
+
+And, First, I found it ought to be exceeding _quick_, such as those motions
+of _fermentation_ and _putrefaction_, whereby, certainly, the parts are
+exceeding nimbly and violently mov'd; and that, because we find those
+motions are able more minutely to shatter and divide the body, then the
+most violent heats _menstruums_ we yet know. And that fire is nothing else
+but such a _dissolution_ of the Burning body, made by the most _universal
+menstruum_ of all _sulphureous bodies_, namely, the Air, we shall in an
+other place of this Tractate endeavour to make probable. And that, in all
+extreamly hot shining bodies, there is a very quick motion that causes
+Light, as well as a more robust that causes Heat, may be argued from the
+celerity wherewith the bodyes are dissolv'd.
+
+Next, it must be a _Vibrative motion_. And for this the newly mention'd
+_Diamond_ affords us a good argument; since if the motion of the parts did
+not return, the Diamond must after many rubbings decay and be wasted: but
+we have no reason to suspect the latter, especially if we consider the
+exceeding difficulty that is found in cutting or wearing away a Diamond.
+And a Circular motion of the parts is much more improbable, since, if that
+were granted, and they be suppos'd irregular and Angular parts, I see not
+how the parts of the Diamond should hold so firmly together, or remain in
+the same sensible dimensions, which yet they do. Next, if they be
+_Globular_, and mov'd only with a _turbinated_ motion, I know not any cause
+that can impress that motion upon the _pellucid medium_, which yet is done.
+Thirdly, any other _irregular_ motion of the parts one amongst another,
+must necessarily make the body of a fluid consistence, from which it is far
+enough. It must therefore be a _Vibrating_ motion.
+
+And Thirdly, That it is a very _short-vibrating motion_, I think the
+instances drawn from the shining of Diamonds will also make probable. For a
+Diamond being the hardest body we yet know in the World, and consequently
+the least apt to yield or bend, must consequently also have its
+_vibrations_ exceeding short.
+
+And these, I think, are the three principal proprieties of a motion,
+requisite to produce the effect call'd Light in the Object.
+
+The next thing we are to consider, is the way or manner of the _trajection_
+of this motion through the interpos'd pellucid body to the eye: And here it
+will be easily granted,
+
+First, That it must be a body _susceptible_ and _impartible_ of this motion
+that will deserve the name of a Transparent. And next, that the parts of
+such a body must be _Homogeneous_, or of the same kind. Thirdly, that the
+constitution and motion of the parts must be such, that the appulse of the
+luminous body may be communicated or propagated through it to the greatest
+imaginable distance in the least imaginable time, though I see no reason to
+affirm, that it must be in an instant: For I know not any one Experiment or
+observation that does prove it. And, whereas it may be objected, That we
+see the Sun risen at the very instant when it is above the sensible
+Horizon, and that we see a Star hidden by the body of the Moon at the same
+instant, when the Star, the Moon, and our Eye are all in the same line; and
+the like Observations, or rather suppositions, may be urg'd. I have this to
+answer, That I can as easily deny as they affirm; for I would fain know by
+what means any one can be assured any more of the Affirmative, then I of
+the Negative. If indeed the propagation were very slow, 'tis possible
+something might be discovered by Eclypses of the Moon; but though we should
+grant the progress of the light from the Earth to the Moon, and from the
+Moon back to the Earth again to be full two Minutes in performing, I know
+not any possible means to discover it; nay, there may be some instances
+perhaps of Horizontal Eclypses that may seem very much to favour this
+supposition of the slower progression of Light then most imagine. And the
+like may be said of the Eclypses of the Sun, &c. But of this only by the
+by. Fourthly, That the motion is propagated every way through an
+_Homogeneous medium_ by _direct_ or _straight_ lines extended every way
+like Rays from the center of a Sphere. Fifthly, in an _Homogeneous medium_
+this motion is propagated every way with _equal velocity_, whence
+necessarily every _pulse_ or _vitration_ of the luminous body will generate
+a Sphere, which will continually increase, and grow bigger, just after the
+same manner (though indefinitely swifter) as the waves or rings on the
+surface of the water do swell into bigger and bigger circles about a point
+of it, where, by the sinking of a Stone the motion was begun, whence it
+necessarily follows, that all the parts of these Spheres undulated through
+an _Homogeneous medium_ cut the Rays at right angles.
+
+But because all transparent _mediums_ are not _Homogeneous_ to one another,
+therefore we will next examine how this pulse or motion will be propagated
+through differingly transparent _mediums_. And here, according to the most
+acute and excellent Philosopher _Des Cartes_, I suppose the sign of the
+angle of inclination in the first _medium_ to be to the sign of refraction
+in the second, As the density of the first, to the density of the second.
+By density, I mean not the density in respect of gravity (with which the
+refractions or transparency of _mediums_ hold no proportion) but in respect
+onely to the _trajection_ of the Rays of light, in which respect they only
+differ in this; that the one propagates the pulse more easily and weakly,
+the other more slowly, but more strongly. But as for the pulses themselves,
+they will by the refraction acquire another propriety, which we shall now
+endeavour to explicate.
+
+We will suppose therefore in the first Figure ACFD to be a physical Ray, or
+ABC and DEF to be two Mathematical Rays, _trajected_ from a very remote
+point of a luminous body through an _Homogeneous_ transparent _medium_ LLL,
+and DA, EB, FC, to be small portions of the orbicular impulses which must
+therefore cut the Rays at right angles; these Rays meeting with the plain
+surface NO of a _medium_ that yields an easier _transitus_ to the
+propagation of light, and falling _obliquely_ on it, they will in the
+_medium_ MMM be refracted towards the perpendicular of the surface. And
+because this _medium_ is more easily _trajected_ then the former by a
+third, therefore the point C of the orbicular pulse FC will be mov'd to H
+four spaces in the same time that F the other end of it is mov'd to G three
+spaces, therefore the whole refracted pulse GH shall be _oblique_ to the
+refracted Rays CHK and GI; and the angle GHC shall be an acute, and so much
+the more acute by how much the greater the refraction be, then which
+nothing is more evident, for the sign of the inclination is to the sign of
+refraction as GF to TC the distance between the point C and the
+perpendicular from G on CK, which being as four to three, HC being longer
+then GF is longer also then TC, therefore the angle GHC is less than GTC.
+So that henceforth the parts of the pulses GH and IK are mov'd ascew, or
+cut the Rays at _oblique_ angles.
+
+It is not my business in this place to set down the reasons why this or
+that body should impede the Rays more, others less: as why Water should
+transmit the Rays more easily, though more weakly than air. Onely thus much
+in general I shall hint, that I suppose the _medium_ MMM to have less of
+the transparent undulating subtile matter, and that matter to be less
+implicated by it, whereas LLL I suppose to contain a greater quantity of
+the fluid undulating substance, and this to be more implicated with the
+particles of that _medium_.
+
+But to proceed, the same kind of _obliquity_ of the Pulses and Rays will
+happen also when the refraction is made out of a more easie into a more
+difficult _mediu_; as by the calculations of GQ & CSR which are refracted
+from the perpendicular. In both which calculations 'tis _obvious_ to
+observe, that always that part of the Ray towards which the refraction is
+made has the end of the _orbicular pulse_ precedent to that of the other
+side. And always, the oftner the refraction is made the same way, Or the
+greater the single refraction is, the more is this unequal progress. So
+that having found this odd propriety to be an inseparable concomitant of a
+refracted Ray, not streightned by a contrary refraction, we will next
+examine the refractions of the Sun-beams, as they are suffer'd onely to
+pass through a small passage, _obliquely_ out of a more difficult, into a
+more easie _medium_.
+
+Let us suppose therefore ABC in the second Figure to represent a large
+_Chimical Glass-body_ about two foot long, filled with very fair Water as
+high as AB, and inclin'd in a convenient posture with B towards the Sun:
+Let us further suppose the top of it to be cover'd with an _opacous_ body,
+all but the hole ab, through which the Sun-beams are suffer'd to pass into
+the Water, and are thereby refracted to cdef, against which part, if a
+Paper be expanded on the outside, there will appear all the colours of the
+Rain-bow, that is, there will be generated the two principal colours,
+_Scarlet_ and _Blue_, and all the _intermediate_ ones which arise from the
+composition and dilutings of these two, that is, cd shall exhibit a
+_Scarlet_, which toward d is diluted into a _Yellow_; this is the
+refraction of the Ray, ik, which comes from the underside of the Sun; and
+the Ray ef shall appear of a deep _Blue_, which is gradually towards e
+diluted into a pale _Watchet-blue_. Between d and e the two _diluted_
+colours. _Blue_ and _Yellow_ are mixt and compounded into a _Green_; and
+this I imagine to be the reason why _Green_ is so acceptable a colour to
+the eye, and that either of the two extremes are, if intense, rather a
+little offensive, namely, the being plac'd in the middle between the two
+extremes, and compounded out of both those, _diluted_ also, or somewhat
+qualifi'd, for the _composition_, arising from the mixture of the two
+extremes _undiluted_, makes a _Purple_, which though it be a lovely colour,
+and pretty acceptable to the eye, yet is it nothing comparable to the
+ravishing pleasure with which a curious and well tempered _Green_ affects
+the eye. If removing the Paper, the eye be plac'd against cd, it will
+perceive the lower side of the Sun (or a Candle at night which is much
+better, because it offends not the eye, and is more easily manageable) to
+be of a deep _Red_, and if against ef it will perceive the upper part of
+the luminous body to be of a deep _Blue_; and these colours will appear
+deeper and deeper, according as the Rays from the luminous body fall more
+_obliquely_ on the surface of the Water, and thereby suffer a greater
+refraction, and the more distinct, the further cdef is removed from the
+trajecting hole.
+
+So that upon the whole, we shall find that the reason of the _Phaenomena_
+seems to depend upon the _obliquity_ of the _orbicular pulse_, to the Lines
+of Radiation, and in particular, that the Ray cd which constitutes the
+_Scarlet_ has its inner parts, namely those which are next to the middle of
+the luminous body, precedent to the outermost which are contiguous to the
+dark and _unradiating_ skie. And that the Ray ef which gives a _Blue_, has
+its outward part, namely, that which is contiguous to the dark side
+precedent to the pulse from the innermost, which borders on the bright
+_area_ of the luminous body.
+
+We may observe further, that the cause of the _diluting_ of the colours
+towards the middle, proceeds partly from the wideness of the hole through
+which the Rays pass, whereby the Rays from several parts of the luminous
+body, fall upon many of the same parts between c and f as is more manifest
+by the Figure: And partly also from the nature of the refraction it self,
+for the vividness or strength of the two terminating colours, arising
+chiefly as we have seen, from the very great difference that is betwixt the
+outsides of those _oblique undulations_ & the dark Rays circumambient, and
+that disparity betwixt the _approximate_ Rays, decaying gradually: the
+further inward toward the middle of the luminous body they are remov'd, the
+more must the colour approach to a white or an undisturbed light.
+
+Upon the calculation of the refraction and reflection from a Ball of Water
+or Glass, we have much the same _Phaenomena_, namely, an _obliquity_ of the
+undulation in the same manner as we have found it here. Which, because it
+is very much to our present purpose, and affords such an _Instancia
+crucis_, as no one that I know has hitherto taken notice of, I shall
+further examine. For it does very plainly and positively distinguish, and
+shew, which of the two _Hypotheses_, either the _Cartesian_ or this is to
+be followed, by affording a generation of all the colors in the Rainbow,
+where according to the _Cartesian Principles_ there should be none at all
+generated. And secondly, by affording an instance that does more closely
+confine the cause of these _Phaenomena_ of colours to this present
+_Hypothesis_.
+
+And first, for the _Cartesian_, we have this to object against it, That
+whereas he says (_Meteorum Cap. 8. Sect. 5._) _Sed judicabam unicam
+(refractione scilicet) ad minimum requiri, & quidem talem ut ejus effectus
+alia contraria (refractione) non destruatur: Nam experientia docet si
+superficies _NM_ & _NP_ (nempe refringentes) Parallelae forent, radios
+tantundem per alteram iterum erectos quantum per unam frangerentur, nullos
+colores depicturos_; This Principle of his holds true indeed in a prisme
+where the refracting surfaces are plain, but is contradicted by the Ball or
+Cylinder, whether of Water Or Glass, where the refracting surfaces are
+Orbicular or Cylindrical. For if we examine the passage of any _Globule_ or
+Ray of the primary _Iris_, we shall find it to pass out of the Ball or
+Cylinder again, with the same inclination and refraction that it enter'd in
+withall, and that that last refraction by means of the _intermediate_
+reflection shall be the same as if without any reflection at all the Ray
+had been twice refracted by two Parallel surfaces.
+
+And that this is true, not onely in one, but in every Ray that goes to the
+constitution of the Primary Iris; nay, in every Ray, that suffers only two
+refractions, and one reflection, by the surface of the round body, we shall
+presently see most evident, if we repeat the _Cartesian Scheme_, mentioned
+in the tenth _Section_ of the eighth _Chapter_ of his _Meteors_, where
+EFKNP in the third Figure[9] is one of the Rays of the Primary Iris, twice
+refracted at F and N, and once reflected at K by the surface of the
+Water-ball. For, first it is evident, that KF and KN are equal, because KN
+being the reflected part of KF they have both the same inclination on the
+surface K that is the angles FKT, and NKV made by the two Rays and the
+Tangent of K are equal, which is evident by the Laws of reflection; whence
+it will follow also, that KN has the same inclination on the surface N, or
+the Tangent of it XN that the Ray KF has to the surface F, or the Tangent
+of it FY, whence it must necessarily follow, that the refractions at F and
+N are equal, that is, KFE and KNP are equal. Now, that the surface N is by
+the reflection at K made parallel to the surface at F, is evident from the
+principles of reflection; for reflection being nothing but an inverting of
+the Rays, if we re-invert the Ray KNP, and make the same inclinations below
+the line TKV that it has above, it will be most evident, that KH the
+inverse of KN will be the continuation of the line FK, and that LHI the
+inverse of OX is parallel to FY. And HM the inverse of NP is Parallel to EF
+for the angle KHI is equal to KNO which is equal to KFY, and the angle KHM
+is equal to KNP which is equal to KFE which was to be prov'd.
+
+So that according to the above mentioned _Cartesian_ principles there
+should be generated no colour at all in a Ball of Water or Glass by two
+refractions and one reflection, which does hold most true indeed, if the
+surfaces be plain, as may be experimented with any kind of prisme where the
+two refracting surfaces are equally inclin'd to the reflecting; but in this
+the _Phaenomena_ are quite otherwise.
+
+The cause therefore of the generation of colour must not be what _Des
+Cartes_ assigns, namely, a certain _rotation_ of the _Globuli aetherei_,
+which are the particles which he supposes to constitute the _Pellucid
+medium_, But somewhat else, perhaps what we have lately supposed, and shall
+by and by further prosecute and explain.
+
+But, First I shall crave leave to propound some other difficulties of his,
+notwithstanding exceedingly ingenious _Hypothesis_, which I plainly confess
+to me seem such; and those are,
+
+First, if that light be (as is affirmed, _Diopt._ cap. 1. Sec. 8.) not so
+properly a motion, as an action or propension to motion, I cannot conceive
+how the eye can come to be sensible of the _verticity_ of a _Globule_,
+which is generated in a drop of Rain, perhaps a mile off from it. For that
+_Globule_ is not carry'd to the eye according to his formerly recited
+Principle; and if not so, I cannot conceive how it can communicate its
+_rotation_, or circular motion to the line of the _Globules_ between the
+drop and the eye. It cannot be by means of every ones turning the next
+before him; for if so, then onely all the _Globules_ that are in the odd
+places must be turned the same way with the first, namely, the 3. 5. 7. 9.
+11, &c. but all the _Globules_ interposited between them in the even
+places; namely, the 2. 4. 6. 8. 10. &c. must be the quite contrary, whence,
+according to the _Cartesian Hypothesis_, there must be no distinct colour
+generated, but a confusion. Next, since the _Cartesian Globuli_ are
+suppos'd (_Principiorum Philosoph._ Part. 3. Sec. 86.) to be each of them
+continually in motion about their centers, I cannot conceive how the eye is
+able to distinguish this new generated motion from their former inherent
+one, if I may so call that other wherewith they are mov'd or _turbinated_,
+from some other cause than refraction. And thirdly, I cannot conceive how
+these motions should not happen sometimes to oppose each other, and then,
+in stead of a _rotation_, there would be nothing but a direct motion
+generated, and consequently no colour. And fourthly, I cannot conceive, how
+by the _Cartesian Hypothesis_ it is possible to give any plausible reason
+of the nature of the Colours generated in the thin _laminae_ of these our
+_Microscopical Observations_; for in many of these, the refracting and
+reflecting surfaces are parallel to each other, and consequently no
+_rotation_ can be generated, nor is there any necessity of a shadow or
+termination of the bright Rays, such as is suppos'd (_Chap._ 8. Sec. 5. _Et
+praeterea observavi umbram quoque, aut limitationem luminis requiri:_ and
+_Chap._ 8. Sec. 9.) to be necessary to the generation of any distinct
+colours; Besides that, here is oftentimes one colour generated without any
+of the other appendant ones, which cannot be by the _Cartesian Hypothesis_.
+
+There must be therefore some other propriety of refraction that causes
+colour. And upon the examination of the thing, I cannot conceive any one
+more general, inseparable, and sufficient, than that which I have before
+assign'd. That we may therefore see how exactly our _Hypothesis_ agrees
+also with the _Phaenomena_ of the refracting round body, whether _Globe_ or
+_Cylinder_, we shall next subjoyn our _Calculation_ or _Examen_ of it.
+
+And to this end, we will calculate any two Rays: as for instance;[10] let
+EF be a Ray cutting the _Radius_ CD (divided into 20. parts) in G 16. parts
+distant from C, and ef another Ray, which cuts the same _Radius_ in g 17.
+parts distant, these will be refracted to K and k, and from thence
+reflected to N and n, and from thence refracted toward P and p; therefore
+the Arch Ff will be 5.d 5'. The Arch FK 106.d 30'. the Arch fk 101.d 2'.
+The line FG 6000. and fg 5267. therefore hf. 733. therefore Fc 980, almost.
+The line FK 16024. and fk 15436. therefore Nd 196. and no 147 almost, the
+line Nn 1019 the Arch Nn 5.d 51'. therefore the Angle Nno is 34.d 43'.
+therefore the Angle Non is 139.d 56'. which is almost 50.d more than a
+right Angle.
+
+It is evident therefore by this _Hypothesis_, that at the same time that ef
+touches f. EF is arrived at c. And by that time efkn is got to n, EFKN is
+got to d and when it touches N, the pulse of the other Ray is got to o. and
+no farther, which is very short of the place it should have arriv'd to, to
+make the Ray np to cut the _orbicular pulse_ No at right Angles: therefore
+the Angle Nop is an acute Angle, but the quite contrary of this will
+happen, if 17. and 18. be calculated in stead of 16. and 17. both which
+does most exactly agree with the _Phaenomena_: For if the Sun, or a Candle
+(which is better) be placed about Ee, and the eye about Pp, the Rays EFef
+at 16. and 17. will paint the side of the luminous object toward np _Blue_,
+and towards NP _Red_. But the quite contrary will happen when EF is 17. and
+ef 18. for then towards NP shall be a _Blue_, and towards np a _Red_,
+exactly according to the calculation. And there appears the _Blue_ of the
+Rainbow, where the two _Blue_ sides of the two Images unite, and there the
+_Red_ where the two _Red_ sides unite, that is, where the two Images are
+just disappearing; which is, when the Rays EF and NP produc'd till they
+meet, make an Angle of about 41. and an half; the like union is there of
+the two Images in the Production of the _Secundary Iris_, and the same
+causes, as upon calculation may appear; onely with this difference, that it
+is somewhat more faint, by reason of the duplicate reflection, which does
+always weaken the impulse the oftner it is repeated.
+
+Now, though the second refraction made at Nn be convenient, that is, do
+make the Rays glance the more, yet is it not altogether requisite; for it
+is plain from the calculation, that the pulse dn is sufficiently _oblique_
+to the Rays KN and kn, as wel as the pulse fc is _oblique_ to the Rays FK &
+fk. And therefore if a piece of very fine Paper be held close against Nn
+and the eye look on it either through the Ball as from D, or from the other
+side, as from B. there shall appear a Rainbow, or colour'd line painted on
+it with the part toward X appearing _Red_, towards O, _Blue_; the same also
+shall happen, if the Paper be placed about Kk, for towards T shall appear a
+_Red_, and towards V a _Blue_, which does exactly agree with this my
+_Hypothesis_, as upon the calculation of the progress of the pulse will
+most easily appear.
+
+Nor do these two observations of the colours appearing to the eye about p
+differing from what they appear on the Paper at N contradict each other;
+but rather confirm and exactly agree with one another, as will be evident
+to him that examines the reasons set down by the ingenious. _Des Cartes_ in
+the 12. _Sect._ of the 8. _Chapter of his Meteors_, where he gives the true
+reason why the colours appear of a quite contrary order to the eye, to what
+they appear'd on the Paper if the eye be plac'd in steed of the Paper: And
+as in the Prisme, so also in the Water-drop, or Globe the _Phaenomena_, and
+reason are much the same.
+
+Having therefore shewn that there is such a propriety in the _prisme_ and
+water _Globule_ whereby the pulse is made _oblique_ to the progressive, and
+that so much the more, by how much greater the refraction is, I shall in
+the next place consider, how this conduces to the production of colours,
+and what kind of impression it makes upon the bottom of the eye; and to
+this end it will be requisite to examine this _Hypothesis_ a little more
+particularly.
+
+First therefore, if we consider the manner of the progress of the pulse, it
+will seem rational to conclude, that that part or end of the pulse which
+precedes the other, must necessarily be somwhat more _obtunded_, or
+_impeded_ by the resistance of the transparent _medium_, than the other
+part or end of it which is subsequent, whose way is, as it were, prepared
+by the other; especially if the adjacent _medium_ be not in the same manner
+enlightned or agitated. And therefore (in the fourth _Figure_ of the sixth
+_Iconism_) the Ray AAAHB will have its side HH more deadned by the
+resistance of the dark or quiet _medium_ PPP, Whence there will be a kind
+of deadness superinduc'd on the side HHH, which will continually increase
+from B, and strike deeper and deeper into the Ray by the line BR; Whence
+all the parts of the triangle, RBHO will be of a dead _Blue_ colour, and so
+much the deeper, by how much the nearer they lie to the line BHH, which is
+most deaded or impeded, and so much the more _dilute_, by how much the
+nearer it approaches the line BR. Next on the other side of the Ray AAN,
+the end A of the pulse AH will be promoted, or made stronger, having its
+passage already prepar'd as 'twere by the other parts preceding, and so its
+impression wil be stronger; And because of its _obliquity_ to the Ray,
+there will be propagated a kind of faint motion into QQ the adjacent dark
+or quiet _medium_, which faint motion will spread further and further into
+QQ as the Ray is propagated further and further from A, namely, as far as
+the line MA, whence all the triangle MAN will be ting'd with a _Red_, and
+that _Red_ will be the deeper the nearer it approaches the line MA, and the
+_paler_ or _yellower_ the nearer it is the line NA. And if the Ray be
+continued, so that the lines AN and BR (which are the bounds of the _Red_
+and _Blue diluted_) do meet and cross each other, there will be beyond that
+intersection generated all kinds of _Greens_.
+
+Now, these being the proprieties of every single refracted Ray of light, it
+will be easie enough to consider what must be the result of very many such
+Rays collateral: As if we suppose infinite such Rays _interjacent_ between
+AKSB and ANOB, which arc the terminating: For in this case the Ray AKSB
+will have its _Red_ triangle intire, as lying next to the dark or quiet
+_medium_, but the other side of it BS will have no _Blue_, because the
+_medium adjacent_ to it SBO, is mov'd or enlightned, and consequently that
+light does destroy the colour. So likewise will the Ray ANOB lose its
+_Red_, because the _adjacent medium_ is mov'd or enlightned, but the other
+side of the Ray that is _adjacent_ to the dark, namely, AHO will preserve
+its _Blue_ entire, and these Rays must be so far produc'd as till AN and BR
+cut each other, before there will be any _Green_ produc'd. From these
+Proprieties well consider'd, may be deduc'd the reasons of all the
+_Phaenomena_ of the _prisme_, and of the _Globules_ or drops of Water which
+conduce to the production of the Rainbow.
+
+Next for the impression they make on the _Retina_, we will further examine
+this _Hypothesis_: Suppose therefore ABCDEF, in the fifth _Figure_, to
+represent the Ball of the eye: on the _Cornea_ of which ABC two Rays GACH
+and KCAI (which are the terminating Rays of a luminous body) falling, are
+by the refraction thereof collected or _converg'd_ into two points at the
+bottom of the eye. Now, because these terminating Rays, and all the
+_intermediate_ ones which come from any part of the luminous body, are
+suppos'd by some sufficient refraction before they enter the eye, to have
+their pulses made _oblique_ to their progression, and consequently each Ray
+to have potentially _superinduc'd_ two proprieties, or colours, viz., a
+_Red_ on the one side, and a _Blue_ on the other, which notwithstanding are
+never actually manifest, but when this or that Ray has the one or the other
+side of it bordering on a dark or unmov'd _medium_, therefore as soon as
+these Rays are entred into the eye and so have one side of each of them
+bordering on a dark part of the humours of the eye, they will each of them
+actually exhibit some colour; therefore ADC the production of GACH will
+exhibit a _Blue_, because the side CD is _adjacent_ to the dark _medium_
+CQDC, but nothing of a _Red_, because its side AD is _adjacent_ to the
+enlightned _medium_ ADFA: And all the Rays that from the points of the
+luminous body are collected on the parts of the _Retina_ between D and F
+shall have their _Blue_ so much the more _diluted_ by how much the farther
+these points of collection are distant from D towards F; and the Ray AFC
+the production of KCAI, will exhibit a _Red_, because the side AF is
+adjacent to the dark or quiet _medium_ of the eye APFA, but nothing of a
+_Blue_, because its side CF is _adjacent_ to the enlightned _medium_ CFDC,
+and all the Rays from the intermediate parts of the luminous body that are
+collected between F and D shall have their _Red_ so much the more diluted,
+by how much the farther they are distant from F towards D.
+
+Now, because by the refraction in the _Cornea_, and some other parts of the
+eye, the sides of each Ray, which before were almost parallel, are made to
+_converge_ and meet in a point at the bottom of the eye, therefore that
+side of the _pulse_ which preceded before these refractions, shall first
+touch the _Retina_, and the other side last. And therefore according as
+this or that side, or end of the pulse shall be impeded, accordingly will
+the _impressions_ on the _Retina_ be varied; therefore by the Ray GACH
+refracted by the _Cornea_ to D there shall be on that point a stroke or
+impression confus'd, whose weakest end, namely, that by the line CD shall
+precede, and the stronger, namely, that by the line AD shall follow. And by
+the Ray KCAI refracted to F, there shall be on that part a confus'd stroke
+or impression, whose strongest part, namely, that by the line CF shal
+precede, and whose weakest or impeded, namely, that by the line AF shall
+follow, and all the intermediate points between F and D will receive
+impressions from the _converg'd_ Rays so much the more like the impressions
+on F and D by how much the nearer they approach that or this.
+
+From the consideration of the proprieties of which impressions, we may
+collect these short definitions of Colours: That _Blue is an impression on
+the Retina of an oblique and confus'd pulse of light, whose weakest part
+precedes, and whose strongest follows._ And, that _Red is an impression on
+the Retina of an oblique and confus'd pulse of light, whose strongest part
+precedes, and whose weakest follows._
+
+Which proprieties, as they have been already manifested, in the Prisme and
+falling drops of Rain, to be the causes of the colours there generated, may
+be easily found to be the efficients also of the colours appearing in thin
+_laminated_ transparent bodies; for the explication of which, all this has
+been premised.
+
+And that this is so, a little closer examination of the _Phaenomena_ and
+the _Figure_ of the body, by this _Hypothesis_ will make evident.
+
+For first (as we have already observed) the _laminated_ body must be of a
+determinate thickness, that is, it must not be thinner then such a
+determinate quantity; for I have always observ'd, that neer the edges of
+those which are exceeding thin, the colours disappear, and the part grows
+white; nor must it be thicker then another determinate quantity; for I have
+likewise observ'd, that beyond such a thickness, no colours appear'd, but
+the Plate looked white, between which two determinate thicknesses were all
+the colour'd Rings; of which in some substances I have found ten or twelve,
+in others not half so many, which I suppose depends much upon the
+transparency of the _laminated_ body. Thus though the consecutions are the
+same in the scumm or the skin on the top of metals; yet in those
+consecutions in the same colour is not so often repeated as in the
+consecutions in thin Glass, or in Sope-water, or any other more transparent
+and glutinous liquor; for in these I have observ'd, _Red, Yellow, Green,
+Blue, Purple; Red, Yellow, Green, Blue, Purple; Red, Yellow, Green, Blue,
+Purple; Red, Yellow, &c._ to succeed each other, ten or twelve times, but
+in the other more _opacous_ bodies the consecutions will not be half so
+many.
+
+And therefore secondly, the _laminated_ body must be transparent, and this
+I argue from this, that I have not been able to produce any colour at all
+with an _opacous_ body, though never so thin. And this I have often try'd,
+by pressing small _Globule_ of _Mercury_ between two smooth Plates of
+Glass, whereby I have reduc'd that body to a much greater thinness then was
+requisite to exhibit the colours with a transparent body.
+
+Thirdly, there must be a considerable reflecting body adjacent to the under
+or further side of the _lamina_ or _plate_: for this I always found, that
+the greater that reflection was, the more vivid were the appearing colours.
+
+From which Observations, is most evident, that the reflection from the
+under or further side of the body is the principal cause of the production
+of these colours; which, that it is so, and how it conduces to that effect,
+I shall further explain in the following Figure, which is here described of
+a very great thickness, as if it had been view'd through the _Microscope_;
+and 'tis indeed much thicker than any _Microscope_ (I have yet us'd) has
+been able to shew me those colour'd plates of Glass, or _Muscovie-glass_,
+which I have not without much trouble view'd with it, for though I have
+endeavoured to magnifie them as much as the Glasses were capable of, yet
+are they so exceeding thin, that I have not hitherto been able positively
+to determine their thickness. This Figure therefore I here represent, is
+wholy _Hypothetical_.
+
+Let ABCDHFE in the sixth Figure be a _frustum_ of _Muscovy-glass_, thinner
+toward the end AE, and thicker towards DF. Let us first suppose the Ray
+aghb coming from the Sun, of some remote luminous object to fall
+_obliquely_ on the thinner plate BAE, part therefore is reflected back by
+cghd, the first _Superficies_; whereby the perpendicular pulse ab is after
+reflexion propagated by cd, cd, equally remote from each other with ab, ab,
+so that ag + gc, or bh + hd are either of them equal to aa, as is also cc,
+but the body BAE being transparent, a part of the light of this Ray is
+refracted in the surface AB, and propagated by gikh to the surface EF,
+whence it is reflected and refracted again by the surface AB. So that after
+two refractions and one reflection, there is propagated a kind of fainter
+Ray emnf, whose pulse is not only weaker by reason of the two refractions
+in the surface AB, but by reason of the time spent in passing and repassing
+between the two surfaces AB and EF, ef which is this fainter or weaker
+pulse comes behind the pulse cd; so that hereby (the surfaces AB, and EF
+being so neer together, that the eye cannot _discriminate_ them from one)
+this confus'd or _duplicated_ pulse, whose strongest part precedes, and
+whose weakest follows, does produce on the _Retina_, (or the _optick nerve_
+that covers the bottom of the eye) the sensation of a _Yellow_.
+
+And secondly, this _Yellow_ will appear so much the deeper, by how much the
+further back towards the middle between cd and cd the spurious pulse ef is
+remov'd, as in 2 where the surface BC being further remov'd from EF, the
+weaker pulse ef will be nearer to the middle, and will make an impression
+on the eye of a _Red_.
+
+But thirdly, if the two reflecting surfaces be yet further remov'd asunder
+(as in 3 CD and EF are) then will the weaker pulse be so farr behind, that
+it will be more then half the distance between cd and cd. And in this case
+it will rather seem to precede the following stronger pulse, then to follow
+the preceding one, and consequently a _Blue_ will be generated. And when
+the weaker pulse is just in the middle between two strong ones, then is a
+deep and lovely _Purple_ generated; but when the weaker pulse ef is very
+neer to cd, then is there generated a _Green_, which will be _bluer_, or
+_yellower_, according as the _approximate_ weak pulse does precede or
+follow the stronger.
+
+Now fourthly, if the thicker Plate chance to be cleft into two thinner
+Plates, as CDFE is divided into two Plates by the surface GH then from the
+composition arising from the three reflections in the surfaces CD, GH, and
+EF, there will be generated several compounded or mixt colours, which will
+be very differing, according as the proportion between the thicknesses of
+those two divided Plates CDHG, and GHFE are varied.
+
+And _fifthly_, if these surfaces CD and FE are further remov'd asunder, the
+weaker pulse will yet lagg behind much further, and not onely be
+_coincident_ with the second, cd, but lagg behind that also, and that so
+much the more, by how much the thicker the Plate be; so that by degrees it
+will be _coincident_ with the third cd backward also, and by degrees, as
+the Plate grows thicker with a fourth, and so onward to a fifth, sixth,
+seventh, or eighth; so that if there be a thin transparent body, that from
+the greatest thinness requisite to produce colours, does, in the manner of
+a Wedge, by degrees grow to the greatest thickness that a Plate can be of,
+to exhibit a colour by the reflection of Light from such a body, there
+shall be generated several consecutions of colours, whose order from the
+thin end towards the thick, shall be _Yellow, Red, Purple, Blue, Green;
+Yellow, Red, Purple, Blue, Green; Yellow, Red, Purple, Blue, Green;
+Yellow_, &c. and these so often repeated, as the weaker pulse does lose
+paces with its _Primary_, or first pulse, and is _coincident_ with a
+second, third, fourth, fifth, sixth, &c. pulse behind the first. And this,
+as it is _coincident_, or follows from the first _Hypothesis_ I took of
+colours, so upon experiment have I found it in multitudes of instances that
+seem to prove it. One thing which seems of the greatest concern in this
+_Hypothesis_, is to determine the greatest or least thickness requisite for
+these effects, which, though I have not been wanting in attempting, yet so
+exceeding thin are these coloured Plates, and so imperfect our
+_Microscope_, that I have not been hitherto successfull, though if my
+endeavours shall answer my expectations, I shall hope to gratifie the
+curious Reader with some things more remov'd beyond our reach hitherto.
+
+Thus have I, with as much brevity as I was able, endeavoured to explicate
+(_Hypothetically_ at least) the causes of the _Phaenomena_ I formerly
+recited, on the consideration of which I have been the more particular.
+
+First, because I think these I have newly given are capable of explicating
+all the _Phaenomena_ of colours, not onely of those appearing in the
+_Prisme_, Water-drop, or Rainbow, and in _laminated_ or plated bodies, but
+of all that are in the world, whether they be fluid or solid bodies,
+whether in thick or thin, whether transparent, or seemingly opacous, as I
+shall in the next Observation further endeavour to shew. And secondly,
+because this being one of the two ornaments of all bodies discoverable by
+the sight, whether looked on with, or without a _Microscope_, it seem'd to
+deserve (somewhere in this Tract, which contains a description of the
+Figure and Colour of some minute bodies) to be somewhat the more intimately
+enquir'd into.
+
+       *       *       *       *       *
+
+
+Observ. X. _Of _Metalline_, and other real Colours._
+
+Having in the former Discourse, from the Fundamental cause of Colour, made
+it probable, that there are but two Colours, and shewn, that the _Phantasm_
+of Colour is caus'd by the sensation of the _oblique_ or uneven pulse of
+Light which is capable of no more varieties than two that arise from the
+two sides of the _oblique_ pulse, though each of those be capable of
+infinite gradations or degrees (each of them beginning from _White_, and
+ending the one in the deepest _Scarlet_ or _Yellow_, the other in the
+deepest _Blue_) I shall in this _Section_ set down some Observations which
+I have made of other colours, such as _Metalline_ powders tinging or
+colour'd bodies and several kinds of tinctures or ting'd liquors, all
+which, together with those I treated of in the former Observation will, I
+suppose, comprise the several subjects in which colour is observ'd to be
+inherent, and the several manners by which it _inheres_, or is apparent in
+them. And here I shall endeavour to shew by what composition all kind of
+compound colours are made, and how there is no colour in the world but may
+be made from the various degrees of these two colours, together with the
+intermixtures of _Black_ and _White_.
+
+And this being so, as I shall anon shew, it seems an evident argument to
+me, that all colours whatsoever, whether in fluid or solid, whether in very
+transparent or seemingly _opacous_, have the same efficient cause, to wit,
+some kind of _refraction_ whereby the Rays that proceed from such bodies,
+have their pulse _obliquated_ or confus'd in the manner I explicated in the
+former _Section_; that is, a _Red_ is caus'd by a duplicated or confus'd
+pulse, whose strongest pulse precedes, and a weaker follows: and a _Blue_
+is caus'd by a confus'd pulse, where the weaker pulse precedes, and the
+stronger follows. And according as these are, more or less, or variously
+mixt and compounded, so are the _sensations_, and consequently the
+_phantasms_ of colours _diversified_.
+
+To proceed therefore; I suppose, that all transparent colour'd bodies,
+whether fluid or solid, do consist at least of two parts, or two kinds of
+substances, the one of a substance of a somewhat differing _refraction_
+from the other. That one of these substances which may be call'd the
+_tinging_ substance, does consist of distinct parts, or particles of a
+determinate bigness which are _disseminated_, or dispers'd all over the
+other: That these particles, if the body be equally and uniformly colour'd,
+are evenly rang'd and dispers'd over the other contiguous body; That where
+the body is deepest ting'd, there these particles are rang'd thickest, and
+where 'tis but faintly ting'd, they are rang'd much thinner, but uniformly.
+That by the mixture of another body that unites with either of these, which
+has a differing refraction from either of the other, quite differing
+effects will be produc'd, that is, the _consecutions_ of the confus'd
+pulses will be much of another kind, and consequently produce other
+_sensations_ and _phantasms_ of colours, and from a _Red_ may turn to a
+_Blue_, or from a _Blue_ to a _Red_, &c.
+
+Now, that this may be the better understood, I shall endeavour to explain
+my meaning a little more sensible by a _Scheme_: Suppose we therefore in
+the seventh _Figure_ of the sixth _Scheme_, that ABCD represents a Vessel
+holding a ting'd liquor, let IIIII, &c. be the clear liquor, and let the
+tinging body that is mixt with it be EE, &c. FF, &c. GG, &c. HH, &c. whose
+particles (whether round, or some other determinate Figure is little to our
+purpose) are first of a determinate and equal bulk. Next, they are rang'd
+into the form of _Quincunx_, or _Equilaterotriangular_ order, which that
+probably they are so, and why they are so, I shall elsewhere endeavour to
+shew. Thirdly, they are of such a nature, as does either more easily or
+more difficultly transmit the Rays of light then the liquor; if more
+easily, a _Blue_ is generated, and if more difficultly, a _Red_ or
+_Scarlet_.
+
+And first, let us suppose the tinging particles to be of a substance that
+does more _impede_ the Rays of light, we shall find that the pulse or wave
+of light mov'd from AD to BC, will proceed on, through the containing
+_medium_ by the pulses or waves KK, LL, MM, NN, OO; but because several of
+these Rays that go to the constitution of these pulses will be slugged or
+stopped by the tinging particles E, F, G, H; therefore there shall be
+_secundary_ and weak pulse that shall follow the Ray, namely PP which will
+be the weaker: first, because it has suffer'd many refractions in the
+impeding body; next, for that the Rays will be a little dispers'd or
+confus'd by reason of the refraction in each of the particles, whether
+_round_ or _angular_; and this will be more evident, if we a little more
+closely examine any one particular tinging _Globule_.
+
+Suppose we therefore AB in the eighth _Figure_ of the sixth _Scheme_, to
+represent a tinging _Globule_ or particle which has a greater refraction
+than the liquor in which it is contain'd: Let CD be a part of the pulse of
+light which is _propagated_ through the containing _medium_; this pulse
+will be a little stopt or impeded by the _Globule_, and so by that time the
+pulse is past to EF that part of it which has been impeded by passing
+through the _Globule_, will get but to LM, and so that pulse which has been
+_propagated_ through the _Globule_, to wit, LM, NO, PQ, will always come
+behind the pulses EF, GH, IK, &c.
+
+Next, by reason of the greater impediment in AB, and its _Globular_ Figure,
+the Rays that pass through it will be dispers'd, and very much scatter'd.
+Whence CA and DB which before went _direct_ and _parallel_, will after the
+refraction in AB, _diverge_ and spread by AP, and BQ; so that as the Rays
+do meet with more and more of these tinging particles in their way, by so
+much the more will the pulse of light further lagg behind the clearer
+pulse, or that which has fewer refractions, and thence the deeper will the
+colour be, and the fainter the light that is trajected through it; for not
+onely many Rays are reflected from the surfaces of AB, but those Rays that
+get through it are very much disordered.
+
+By this _Hypothesis_ there is no one experiment of colour that I have yet
+met with, but may be, I conceive, very rationably solv'd, and perhaps, had
+I time to examine several particulars requisite to the demonstration of it,
+I might prove it more than probable, for all the experiments about the
+changes and mixings of colours related in the Treatise of Colours,
+published by the _Incomparable_ Mr. _Boyle_, and multitudes of others which
+I have observ'd, do so easily and naturally flow from those principles,
+that I am very apt to think it probable, that they own their production to
+no other _secundary_ cause: As to instance in two or three experiments. In
+the twentieth Experiment, this _Noble Authour_ has shewn that the deep
+_bluish purple-colour_ of _Violets_, may be turn'd into a _Green_, by
+_Alcalizate Salts_, and to a _Red_ by acid; that is, a _Purple_ consists of
+two colours, a deep _Red_, and a deep _Blue_; when the _Blue_ is diluted,
+or altered, or destroy'd by _acid Salts_, the _Red_ becomes predominant,
+but when the _Red_ is diluted by _Alcalizate_, and the _Blue_ heightned,
+there is generated a _Green_; for of a _Red_ diluted, is made a _Yellow_,
+and _Yellow_ and _Blue_ make a _Green_.
+
+Now, because the _spurious_ pulses which cause a _Red_ and a _Blue_, do the
+one follow the clear pulse, and the other precede it, it usually follows,
+that those _Saline_ refracting bodies which do _dilute_ the colour of the
+one, do deepen that of the other. And this will be made manifest by almost
+all kinds of _Purples_, and many sorts of _Greens_, both these colours
+consisting of mixt colours; for if we suppose A and A in the ninth Figure,
+to represent two pulses of clear light, which follow each other at a
+convenient distance, AA, each of which has a _spurious_ pulse preceding it,
+as BB, which makes a _Blue_, and another following it, as CC, which makes a
+_Red_, the one caus'd by tinging particles that have a greater refraction,
+the other by others that have a less refracting quality then the liquor or
+_Menstruum_ in which these are dissolv'd, whatsoever liquor does so alter
+the refraction of the one, without altering that of the other part of the
+ting'd liquor, must needs very much alter the colour of the liquor; for if
+the refraction of the _dissolvent_ be increas'd, and the refraction of the
+tinging particles not altered, then will the preceding _spurious_ pulse be
+shortned or stopt, and not out-run the clear pulse so much; so that BB will
+become EE, and the _Blue_ be _diluted_, whereas the other _spurious_ pulse
+which follows will be made to lagg much more, and be further behind AA than
+before, and CC will become _ff_, and so the _Yellow_ or _Red_ will be
+heightned.
+
+A _Saline_ liquor therefore, mixt with another ting'd liquor, may alter the
+colour of it several ways, either by altering the refraction of the liquor
+in which the colour swims: or secondly by varying the refraction of the
+coloured particles, by uniting more intimately either with some particular
+_corpuscles_ of the tinging body, or with all of them, according as it has
+a _congruity_ to some more especially, or to all alike: or thirdly, by
+uniting and interweaving it self with some other body that is already
+joyn'd with the tinging particles, with which substance it may have a
+_congruity_, though it have very little with the particles themselves: or
+fourthly, it may alter the colour of a ting'd liquor by dis-joyning certain
+particles which were before united with the tinging particles, which though
+they were somewhat _congruous_ to these particles, have yet a greater
+_congruity_ with the newly _infus'd Saline menstruum_. It may likewise
+alter the colour by further dissolving the tinging substance into smaller
+and smaller _particles_, and so _diluting_ the colour; or by uniting
+several _particles_ together as in precipitations, and so deepning it, and
+some such other ways, which many experiments and comparisons of differing
+trials together, might easily inform one of.
+
+From these Principles applied, may be made out all the varieties of colours
+observable, either in liquors, or any other ting'd bodies, with great ease,
+and I hope intelligible enough, there being nothing in the _notion_ of
+colour, or in the suppos'd production, but is very conceivable, and may be
+possible.
+
+The greatest difficulty that I find against this _Hypothesis_, is, that
+there seem to be more distinct colours then two, that is, then Yellow and
+Blue. This Objection is grounded on this reason, that there are several
+Reds, which _diluted_, make not a Saffron or pale Yellow, and therefore
+Red, or Scarlet seems to be a third colour distinct from a deep degree of
+Yellow.
+
+To which I answer, that Saffron affords us a deep Scarlet tincture, which
+may be _diluted_ into as pale a Yellow as any, either by making a weak
+solution of the Saffron, by infusing a small parcel of it into a great
+quantity of liquor, as in spirit of Wine, or else by looking through a very
+thin quantity of the tincture, and which may be heightn'd into the
+loveliest Scarlet, by looking through a very thick body of this tincture,
+or through a thinner parcel of it, which is highly _impregnated_ with the
+tinging body, by having had a greater quantity of the Saffron dissolv'd in
+a smaller parcel of the liquor.
+
+Now, though there may be some particles of other tinging bodies that give a
+lovely Scarlet also, which though _diluted_ never so much with liquor, or
+looked on through never so thin a parcel of ting'd liquor, will not yet
+afford a pale Yellow, but onely a kind of faint Red; yet this is no
+argument but that those ting'd particles may have in them the faintest
+degree of Yellow, though we may be unable to make them exhibit it; For that
+power of being _diluted_ depending upon the divisibility of the ting'd
+body, if I am unable to make the tinging particles so thin as to exhibit
+that colour, it does not therefore follow, that the thing is impossible to
+be done; now, the tinging particles of some bodies are of such a nature,
+that unless there be found some way of comminuting them into less bulks
+then the liquor does dissolve them into, all the Rays that pass through
+them must necessarily receive a tincture so deep, as their appropriate
+refractions and bulks compar'd with the proprieties of the dissolving
+liquor must necessarily dispose them to empress, which may perhaps be a
+pretty deep Yellow, or pale Red.
+
+And that this is not _gratis dictum_, I shall add one instance of this
+kind, wherein the thing is most manifest.
+
+If you take Blue _Smalt_, you shall find, that to afford the deepest Blue,
+which _caeteris paribus_ has the greatest particles or sands; and if you
+further divide, or grind those particles on a Grindstone, or _porphyry_
+stone, you may by _comminuting_ the sands of it, _dilute_ the Blue into as
+pale a one as you please, which you cannot do by laying the colour thin;
+for wheresoever any single particle is, it exhibits as deep a Blue as the
+whole mass. Now, there are other Blues, which though never so much ground,
+will not be _diluted_ by grinding, because consisting of very small
+particles, very deeply ting'd, they cannot by grinding be actually
+separated into smaller particles then the operation of the fire, or some
+other dissolving _menstruum_, reduc'd them to already.
+
+Thus all kind of _Metalline_ colours, whether _precipitated_, _sublim'd_,
+_calcin'd_, or otherwise prepar'd, are hardly chang'd by grinding, as
+_ultra marine_ is not more _diluted_; nor is _Vermilion_ or _Red-lead_ made
+of a more faint colour by grinding; for the smallest particles of these
+which I have view'd with my greatest Magnifying-Glass, if they be well
+enlightned, appear very deeply ting'd with their peculiar colours; nor,
+though I have magnified and enlightned the particles exceedingly, could I
+in many of them, perceive them to be transparent, or to be whole particles,
+but the smallest specks that I could find among well ground _Vermilion_ and
+_Red-lead_, seem'd to be a Red mass, compounded of a multitude of less and
+less motes, which sticking together, compos'd a bulk, not one thousand
+thousandth part of the smallest visible sand or mote.
+
+And this I find generally in most _Metalline_ colours, that though they
+consist of parts so exceedingly small, yet are they very deeply ting'd,
+they being so ponderous, and having such a multitude of terrestrial
+particles throng'd into a little room; so that 'tis difficult to find any
+particle transparent or resembling a pretious stone, though not impossible;
+for I have observ'd divers such shining and resplendent colours intermixt
+with the particles of _Cinnaber_, both natural and artificial, before it
+hath been ground and broken or flaw'd into _Vermilion_: As I have also in
+_Orpiment_, _Red-lead_, and _Bise_, which makes me suppose, that those
+_metalline_ colours are by grinding, not onely broken and separated
+actually into smaller pieces, but that they are also flaw'd and brused,
+whence they, for the most part, become _opacous_, like flaw'd Crystal or
+Glass, &c. But for _Smalts_ and _verditures_, I have been able with a
+_Microscope_ to perceive their particles very many of them transparent.
+
+Now, that the others also may be transparent, though they do not appear so
+to the _Microscope_, may be made probable by this Experiment: that if you
+take _ammel_ that is almost _opacous_, and grind it very well on a
+_Porphyry_, or _Serpentine_, the small particles will by reason of their
+flaws, appear perfectly _opacous_; and that 'tis the flaws that produce
+this _opacousness_, may be argued from this, that particles of the same
+_Ammel_ much thicker if unflaw'd will appear somewhat transparent even to
+the eye; and from this also, that the most transparent and clear Crystal,
+if heated in the fire, and then suddenly quenched, so that it be all over
+flaw'd, will appear _opacous_ and white.
+
+And that the particles of _Metalline_ colours are transparent, may be
+argued yet further from this, that the Crystals, or _Vitriols_ of all
+Metals, are transparent, which since they consist of _metalline_ as well as
+_saline_ particles, those _metalline_ ones must be transparent, which is
+yet further confirm'd from this, that they have for the most part,
+_appropriate_ colours; so the _vitriol_ of Gold is Yellow; of Copper, Blue,
+and sometimes Green; of Iron, green; of Tinn and Lead, a pale White; of
+Silver, a pale Blue, _&._
+
+And next, the _Solution_ of all Metals into _menstruums_ are much the same
+with the _Vitriols_, or Crystals. It seems therefore very probable, that
+those colours which are made by the _precipitation_ of those particles out
+of the _menstruums_ by transparent _precipitating_ liquors should be
+transparent also. Thus Gold _precipitates_ with _oyl of Tartar_, or _spirit
+of Urine_ into a brown Yellow, Copper with spirit of _Urine_ into a Mucous
+blue, which retains its transparency. A solution of sublimate (as the same
+Illustrious Authour I lately mention'd shews in his 40. Experiment)
+_precipitates_ with oyl of _Tartar_ _per deliquium_, into an Orange
+colour'd _precipitate_; nor is it less probable, that the _calcination_ of
+those _Vitriols_ by the fire, should have their particles transparent: Thus
+_Saccarum Saturni_, or the _Vitriol of Lead_ by _calcination_ becomes a
+deep Orange-colour'd _minium_, which is a kind of _precipitation_ by some
+Salt which proceeds from the fire; common _Vitriol_ _calcin'd_, yields a
+deep Brown Red, etc.
+
+A third Argument, that the particles of Metals are transparent, is, that
+being _calcin'd_, and melted with Glass, they tinge the Glass with
+transparent colours. Thus the _Calx_ of Silver tinges the Glass on which it
+is anneal'd with a lovely Yellow, or Gold colour, &c.
+
+And that the parts of Metals are transparent, may be farther argued from
+the transparency of Leaf-gold, which held against the light, both to the
+naked eye, and the _Microscope,_ exhibits a deep Green. And though I have
+never seen the other Metals _laminated_ so thin, that I was able to
+perceive them transparent, yet, for Copper and Brass, if we had the same
+conveniency for _laminating_ them, as we have for Gold, we might, perhaps,
+through such plates or leaves, find very differing degrees of Blue, or
+Green; for it seems very probable, that those Rays that rebound from them
+ting'd, with a deep Yellow, or pale Red, as from Copper, or with a pale
+Yellow, as from Brass, have past through them; for I cannot conceive how by
+reflection alone those Rays can receive a tincture, taking any _Hypothesis_
+extant.
+
+So that we see there may a sufficient reason be drawn from these instances,
+why those colours which we are unable to _dilute_ to the palest Yellow, or
+Blue, or Green, are not therefore to be concluded not to be a deeper degree
+of them; for supposing we had a great company of small _Globular_ essence
+Bottles, or round Glass bubbles, about the bigness of a Walnut, fill'd each
+of them with a very deep mixture of Saffron, and that every one of them did
+appear of a deep Scarlet colour, and all of them together did _exhibit_ at
+a distance, a deep dy'd Scarlet body. It does not follow, because after we
+have come nearer to this _congeries_, or mass, and divided it into its
+parts, and examining each of its parts severally or apart, we find them to
+have much the same colour with the whole mats; it does not, I say,
+therefore follow, that if we could break those _Globules_ smaller, or any
+other ways come to see a smaller or thinner parcel of the ting'd liquor
+that fill'd those bubbles, that that ting'd liquor must always appear Red,
+or of a Scarlet hue, since if Experiment be made, the quite contrary will
+ensue; for it is capable of being _diluted_ into the palest Yellow.
+
+Now, that I might avoid all the Objections of this kind, by exhibiting an
+Experiment that might by ocular proof convince those whom other reasons
+would not prevail with, I provided me a _Prismatical Glass_, made hollow,
+just in the form of a Wedge, such as is represented in the tenth _Figure_
+of the sixth _Scheme_. The two _parallelogram_ sides ABCD, ABEF, which met
+at a point, were made of the clearest Looking-glass plates well ground and
+polish'd that I could get; these were joyn'd with hard cement to the
+_triangular_ sides, BCE, ADF, which were of Wood; the _Parallelogram_ base
+BCEF, likewise was of Wood joyn'd on to the rest with hard cement, and the
+whole _Prismatical_ Box was exactly stopt every where, but onely a little
+hole near the base was left, whereby the Vessel could be fill'd with any
+liquor, or emptied again at pleasure.
+
+One of these Boxes (for I had two of them) I fill'd with a pretty deep
+tincture of _Aloes_, drawn onely with fair Water, and then stopt the hole
+with a piece of Wax, then, by holding this Wedge against the Light, and
+looking through it, it was obvious enough to see the tincture of the liquor
+near the edge of the Wedge where it was but very thin, to be a pale but
+well colour'd Yellow, and further and further from the edge, as the liquor
+grew thicker and thicker, this tincture appear'd deeper and deeper, so that
+near the blunt end, which was seven Inches from the edge and three Inches
+and an half thick; it was of a deep and well colour'd Red. Now, the clearer
+and purer this tincture be, the more lovely will the deep Scarlet be, and
+the fouler the tincture be, the more dirty will the Red appear; so that
+some dirty tinctures have afforded their deepest Red much of the colour of
+burnt Oker or _Spanish_ brown; others as lovely a colour as _Vermilion_,
+and some much brighter; but several others, according as the tinctures were
+worse or more foul, exhibited various kinds of Reds, of very differing
+degrees.
+
+The other of these Wedges, I fill'd with a most lovely tincture of Copper,
+drawn from the filings of it, with spirit of _Urine_, and this Wedge held
+as the former against the Light, afforded all manner of Blues, from the
+faintest to the deepest, so that I was in good hope by these two, to have
+produc'd all the varieties of colours imaginable; for I thought by this
+means to have been able by placing the two _Parallelogram_ sides together,
+and the edges contrary ways, to have so mov'd them to and fro one by
+another, as by looking through them in several places, and through several
+thicknesses, I should have compounded, and consequently have seen all those
+colours, which by other like compositions of colours would have ensued.
+
+But insteed of meeting with what I look'd for, I met with somewhat more
+admirable; and that was, that I found my self utterly unable to see through
+them when placed both together, though they were transparent enough when
+asunder; and though I could see through twice the thickness, when both of
+them were fill'd with the same colour'd liquors, whether both with the
+Yellow, or both with the Blue, yet when one was fill'd with the Yellow, the
+other with the Blue, and both looked through, they both appear'd dark,
+onely when the parts near the tops were look'd through, they exhibited
+Greens, and those of very great variety, as I expected, but the Purples and
+other colours, I could not by any means make, whether I endeavour'd to look
+through them both against the Sun, or whether I plac'd them against the
+hole of a darkned room.
+
+But notwithstanding this mis-ghessing, I proceeded on with my trial in a
+dark room, and having two holes near one another, I was able, by placing my
+Wedges against them, to mix the ting'd Rays that past through them, and
+fell on a sheet of white Paper held at a convenient distance from them as I
+pleas'd; so that I could make the Paper appear of what colour I would, by
+varying the thicknesses of the Wedges, and consequently the tincture of the
+Rays that past through the two holes, and sometimes also by varying the
+Paper, that is, insteed of a white Paper, holding a gray, or a black piece
+of Paper.
+
+Whence I experimentally found what I had before imagin'd, that all the
+varieties of colours imaginable are produc'd from several degrees of these
+two colours, namely, Yellow and Blue, or the mixture of them with light and
+darkness, that is, white and black. And all those almost infinite varieties
+which Limners and Painters are able to make by compounding those several
+colours they lay on their Shels or _Palads_, are nothing else, but some
+_compositum_, made up of some one or more, or all of these four.
+
+Now, whereas it may here again be objected, that neither can the Reds be
+made out of the Yellows, added together, or laid on in greater or less
+quantity, nor can the Yellows be made out of the Reds though laid never so
+thin; and as for the addition of White or Black, they do nothing but either
+whiten or darken the colours to which they are added, and not at all make
+them of any other kind of colour: as for instance, _Vermilion_, by being
+temper'd with White Lead, does not at all grow more Yellow, but onely there
+is made a whiter kind of Red. Nor does Yellow _Oker_, though laid never so
+thick, produce the colour of _Vermilion_, nor though it be temper'd with
+Black, does it at all make a Red; nay, though it be temper'd with White, it
+will not afford a fainter kind of Yellow, such as _masticut_, but onely a
+whiten'd Yellow; nor will the Blues be _diluted_ or deepned after the
+manner I speak of, as _Indico_ will never afford so fine a Blue as
+_Ultramarine_ or _Bise_; nor will it, temper'd with _Vermilion_, ever
+afford a Green, though each of them be never so much temper'd with white.
+
+To which I answer, that there is a great difference between _diluting_ a
+colour and whitening of it; for _diluting_ a colour, is to make the
+colour'd parts more thin, so that the ting'd light, which is made by
+trajecting those ting'd bodies, does not receive so deep a tincture; but
+whitening a colour is onely an intermixing of many clear reflections of
+light among the same ting'd parts; deepning also, and darkning or blacking
+a colour, are very different; for deepning a colour, is to make the light
+pass through a greater quantity of the same tinging body; and darkning or
+blacking a colour, is onely interposing a multitude of dark or black spots
+among the same ting'd parts, or placing the colour in a more faint light.
+
+First therefore, as to the former of these operations, that is, diluting
+and deepning, most of the colours us'd by the Limners and Painters are
+incapable of, to wit, _Vermilion_ and _Red-lead_, and _Oker_, because the
+ting'd parts are so exceeding small, that the most curious Grindstones we
+have, are not able to separate them into parts actually divided so small as
+the ting'd particles are; for looking on the most curiously ground
+_Vermilion_, and _Oker_, and _Red-lead_, I could perceive that even those
+small _corpuscles_ of the bodies they left were compounded of many pieces,
+that is, they seem'd to be small pieces compounded of a multitude of lesser
+ting'd parts: each piece seeming almost like a piece of Red Glass, or
+ting'd Crystal all flaw'd; so that unless the Grindstone could actually
+divide them into smaller pieces then those flaw'd particles were, which
+compounded that ting'd mote I could see with my _Microscope_, it would be
+impossible to _dilute_ the colour by grinding, which, because the finest we
+have will not reach to do in _Vermilion_ or _Oker_, therefore they cannot
+at all, or very hardly be _diluted_.
+
+Other colours indeed, whose ting'd particles are such as may be made
+smaller, by grinding their colour, may be _diluted_. Thus several of the
+Blues may be _diluted_, as _Smalt_ and _Bise_; and _Masticut_, which is
+Yellow, may be made more faint: And even _Vermilion_ it self may, by too
+much grinding, be brought to the colour of _Red-lead_, which is but an
+Orange colour, which is confest by all to be very much upon the Yellow.
+Now, though perhaps somewhat of this _diluting_ of _Vermilion_ by overmuch
+grinding may be attributed to the Grindstone, or muller, for that some of
+their parts may be worn off and mixt with the colour, yet there seems not
+very much, for I have done it on a Serpentine-stone with a muller made of a
+Pebble, and yet observ'd the same effect follow.
+
+And secondly, as to the other of these operations on colours, that is, the
+deepning of them, Limners and Painters colours are for the most part also
+uncapable. For they being for the most part _opacous_; and that
+_opacousness_, as I said before, proceeding from the particles, being very
+much flaw'd, unless we were able to joyn and re-unite those flaw'd
+particles again into one piece, we shall not be able to deepen the colour,
+which since we are unable to do with most of the colours which are by
+Painters accounted _opacous_, we are therefore unable to deepen them by
+adding more of the same kind.
+
+But because all those _opacous_ colours have two kinds of beams or Rays
+reflected from them, that is, Rays unting'd, which are onely reflected from
+the outward surface, without at all penetrating of the body, and ting'd
+Rays which are reflected from the inward surfaces or flaws after they have
+suffer'd a two-fold refraction; and because that transparent liquors mixt
+with such _corpuscles_, do, for the most part, take off the former kind of
+reflection; therefore these colours mixt with Water or Oyl, appear much
+deeper than when dry, for most part of that white reflection from the
+outward surface is remov'd. Nay, some of these colours are very much
+deepned by the mixture with some transparent liquor, and that because they
+may perhaps get between those two flaws, and so consequently joyn two or
+more of those flaw'd pieces together; but this happens but in a very few.
+
+Now, to shew that all this is not _gratis dictum_, I shall set down some
+Experiments which do manifest these things to be probable and likely, which
+I have here deliver'd.
+
+For, first, if you take any ting'd liquor whatsoever, especially if it be
+pretty deeply ting'd, and by any means work it into a froth, the
+_congeries_ of that froth shall seem an _opacous_ body, and appear of the
+same colour, but much whiter than that of the liquor out of which it is
+made. For the abundance of reflections of the Rays against those surfaces
+of the bubbles of which the froth consists, does so often rebound the Rays
+backwards, that little or no light can pass through, and consequently the
+froth appears _opacous_.
+
+Again, if to any of these ting'd liquors that will endure the boiling there
+be added a small quantity of fine flower (the parts of which through the
+_Microscope_ are plainly enough to be perceiv'd to consist of transparent
+_corpuscles_) and suffer'd to boyl till it thicken the liquor, the mass of
+the liquor will appear _opacous_, and ting'd with the same colour, but very
+much whiten'd.
+
+Thus, if you take a piece of transparent Glass that is well colour'd, and
+by heating it, and then quenching it in Water, you flaw it all over, it
+will become _opacous_, and will exhibit the same colour with which the
+piece is ting'd, but fainter and whiter.
+
+Or, if you take a Pipe of this transparent Glass, and in the flame of a
+Lamp melt it, and then blow it into very thin bubbles, then break those
+bubbles, and collect a good parcel of those _laminae_ together in a Paper,
+you shall find that a small thickness of those Plates will constitute an
+_opacous_ body, and that you may see through the mass of Glass before it be
+thus _laminated_, above four times the thickness: And besides, they will
+now afford a colour by reflection as other _opacous_ (as they are call'd)
+colours will, but much fainter and whiter than that of the Lump or Pipe out
+of which they were made.
+
+Thus also, if you take _Putty_, and melt it with any transparent colour'd
+Glass, it will make it become an _opacous_ colour'd lump, and to yield a
+paler and whiter colour than the lump by reflection.
+
+The same thing may be done by a preparation of _Antimony_, as has been
+shewn by the Learned _Physician_, Dr. _C.M._ in his Excellent Observations
+and Notes on _Nery's Art of Glass_; and by this means all transparent
+colours become _opacous_, or _ammels_. And though by being ground they lose
+very much of their colour, growing much whiter by reason of the multitude
+of single reflections from their outward surface, as I shew'd afore, yet
+the fire that in the nealing or melting re-unites them, and so renews those
+_spurious_ reflections, removes also those whitenings of the colour that
+proceed from them.
+
+As for the other colours which Painters use, which are transparent, and
+us'd to varnish over all other paintings, 'tis well enough known that the
+laying on of them thinner or thicker, does very much _dilute_ or deepen
+their colour.
+
+Painters Colours therefore consisting most of them of solid particles, so
+small that they cannot be either re-united into thicker particles by any
+Art yet known, and consequently cannot be deepned; or divided into
+particles so small as the flaw'd particles that exhibit that colour, much
+less into smaller, and consequently cannot be _diluted_; It is necessary
+that they which are to imitate all kinds of colours, should have as many
+degrees of each colour as can be procur'd.
+
+And to this purpose, both Limners and Painters have a very great variety
+both of Yellows and Blues, besides several other colour'd bodies that
+exhibit very compounded colours, such as Greens and Purples; and others
+that are compounded of several degrees of Yellow, or several degrees of
+Blue, sometimes unmixt, and sometimes compounded with several other
+colour'd bodies.
+
+The Yellows, from the palest to the deepest Red or Scarlet, which has no
+intermixture of Blue, are _pale and deep Masticut, Orpament, English Oker,
+brown Oker, Red Lead, and Vermilion, burnt English Oker, and burnt brown
+Oker,_ which last have a mixture of dark or dirty parts with them, &c.
+
+Their Blues are several kinds of _Smalts_, and _Verditures_, and _Bise_,
+and _Ultramarine_, and _Indico_, which last has many dirty or dark parts
+intermixt with it.
+
+Their compounded colour'd bodies, as _Pink_, and _Verdigrese_, which are
+Greens, the one a _Popingay_, the other a _Sea-green_; then _Lac_, which is
+a very lovely _Purple_.
+
+To which may be added their Black and White, which they also usually call
+Colours, of each of which they have several kinds, such as _Bone Black_,
+made of _Ivory_ burnt in a close Vessel, and _Blue Black_, made of the
+small coal of _Willow_, or some other Wood; and _Cullens earth_, which is a
+kind of brown Black, &c. Their usual Whites are either artificial or
+natural _White Lead_, the last of which is the best they yet have, and with
+the mixing and tempering these colours together, are they able to make an
+imitation of any colour whatsoever: Their Reds or deep Yellows, they can
+_dilute_ by mixing pale Yellows with them, and deepen their pale by mixing
+deeper with them; for it is not with _Opacous_ colours as it is with
+transparent, where by adding more Yellow to yellow, it is deepned, but in
+_opacous_ _diluted_. They can whiten any colour by mixing White with it,
+and darken any colour by mixing Black, or some dark and dirty colour. And
+in a word, most of the colours, or colour'd bodies they use in Limning and
+Painting, are such, as though mixt with any other of their colours, they
+preserve their own hue, and by being in such very smal parts dispers'd
+through the other colour'd bodies, they both, or altogether represent to
+the eye a _compositum_ of all; the eye being unable, by reason of their
+smalness, to distinguish the peculiarly colour'd particles, but receives
+them as one intire _compositum_: whereas in many of these, the _Microscope_
+very easily distinguishes each of the compounding colours distinct, and
+exhibiting its own colour.
+
+Thus have I by gently mixing _Vermilion_ and _Bise_ dry, produc'd a very
+fine Purple, or mixt colour, but looking on it with the _Microscope_, I
+could easily distinguish both the Red and the Blue particles, which did not
+at all produce the _Phantasm_ of Purple.
+
+To summ up all therefore in a word, I have not yet found any solid colour'd
+body, that I have yet examin'd, perfectly _opacous_; but those that are
+least transparent are _Metalline_ and _Mineral_ bodies, whose particles
+generally, seeming either to be very small, or very much flaw'd, appear for
+the most part _opacous_, though there are very few of them that I have
+look'd on with a _Microscope_, that have not very plainly or
+circumstantially manifested themselves transparent.
+
+And indeed, there seem to be so few bodies in the world that are _in
+minimis_ opacous, that I think one may make it a rational _Query_, Whether
+there be any body absolutely thus _opacous_? For I doubt not at all (and I
+have taken notice of very many circumstances that make me of this mind)
+that could we very much improve the _Microscope_, we might be able to see
+all those bodies very plainly transparent, which we now are fain onely to
+ghess at by circumstances. Nay, the Object Glasses we yet make use of are
+such, that they make many transparent bodies to the eye, seem _opacous_
+through them, which if we widen the Aperture a little, and cast more light
+on the objects, and not charge the Glasses so deep, will again disclose
+their transparency.
+
+Now, as for all kinds of colours that are dissolvable in Water, or other
+liquors, there is nothing so manifest, as that all those ting'd liquors are
+transparent; and many of them are capable of being _diluted_ and compounded
+or mixt with other colours, and divers of them are capable of being very
+much chang'd and heightned, and fixt with several kinds of _Saline
+menstruums_. Others of them upon compounding, destroy or vitiate each
+others colours, and _precipitate_, or otherwise very much alter each others
+tincture. In the true ordering and _diluting_, and deepning, and mixing,
+and fixing of each of which, consists one of the greatest mysteries of the
+Dyers; of which particulars, because our _Microscope_ affords us very
+little information, I shall add nothing more at present; but onely that
+with a very few tinctures order'd and mixt after certain ways, too long to
+be here set down, I have been able to make an appearance of all the various
+colours imaginable, without at all using the help of _Salts_, or _Saline
+menstruums_ to vary them.
+
+As for the mutation of Colours by _Saline menstruums_, they have already
+been so fully and excellently handled by the lately mention'd Incomparable
+_Authour_, that I can add nothing, but that of a multitude of trials that I
+made, I have found them exactly to agree with his Rules and Theories; and
+though there may be infinite instances, yet may they be reduc'd under a few
+Heads, and compris'd within a very few Rules. And generally I find, that
+_Saline menstruums_ are most operative upon those colours that are Purple,
+or have some degree of Purple in them, and upon the other colours much
+less. The _spurious_ pulses that compose which, being (as I formerly noted)
+so very neer the middle between the true ones, that a small variation
+throws them both to one side, or both to the other, and so consequently
+must make a vast mutation in the formerly appearing Colour.
+
+       *       *       *       *       *
+
+
+Observ. XI. _Of _Figures_ observ'd in small Sand._
+
+Sand generally seems to be nothing else but exceeding small Pebbles, or at
+least some very small parcels of a bigger stone; the whiter kind seems
+through the _Microscope_ to consist of small transparent pieces of some
+_pellucid_ body, each of them looking much like a piece of _Alum_, or _Salt
+Gem_; and this kind of Sand is angled for the most part irregularly,
+without any certain shape, and the _granules_ of it are for the most part
+flaw'd, through amongst many of them it is not difficult to find some that
+are perfectly _pellucid_, like a piece of clear Crystal, and divers
+likewise most curiously shap'd, much after the manner of the bigger
+_Stiriae_ of Crystal, or like the small Diamants I observ'd in certain
+Flints, of which I shall by and by relate; which last particular seems to
+argue, that this kind of Sand is not made by the comminution of greater
+transparent Crystaline bodies, but by the _concretion_ or _coagulation_ of
+Water, or some other fluid body.
+
+There are other kinds of courser Sands, which are browner, and have their
+particles much bigger; these, view'd with a _Microscope_, seem much courser
+and more _opacous_ substances, and most of them are of some irregularly
+rounded Figures; and though they seem not so _opacous_ as to the naked eye,
+yet they seem very foul and cloudy, but neither do these want curiously
+transparent, no more than they do regularly figur'd and well colour'd
+particles, as I have often found.
+
+There are multitudes of other kinds of Sands, which in many particulars,
+plainly enough discoverable by the _Microscope_, differ both from these
+last mention'd kinds of Sands, and from one another: there seeming to be as
+great variety of Sands, as there is of Stones. And as amongst Stones some
+are call'd precious from their excellency, so also are there Sands which
+deserve the same Epithite for their beauty; for viewing a small parcel of
+_East-India_ Sand (which was given me by my highly honoured friend, Mr.
+_Daniel Colwall_) and, since that, another parcel, much of the same kind, I
+found several of them, both very transparent like precious Stones, and
+regularly figur'd like Crystal, _Cornish_ Diamants, some Rubies, &c. and
+also ting'd with very lively and deep colours, like _Rubys_, _Saphyrs_,
+_Emeralds_, &c. These kinds of granuls I have often found also in _English_
+Sand. And 'tis easie to make such a counterfeit Sand with deeply ting'd
+Glass, Enamels and Painters colours.
+
+It were endless to describe the multitudes of Figures I have met with in
+these kind of minute bodies, such as _Spherical_, _Oval_, _Pyramidal_,
+_Conical_, _Prismatical_, of each of which kinds I have taken notice.
+
+But amongst many others, I met with none more observable than this pretty
+Shell (described in the _Figure_ X. of the fifth _Scheme_) which, though as
+it was light on by chance, deserv'd to have been omitted (I being unable to
+direct any one to find the like) yet for its rarity was it not
+inconsiderable, especially upon the account of the information it may
+afford us. For by it we have a very good instance of the curiosity of
+Nature in another kind of Animals which are remov'd, by reason of their
+minuteness, beyond the reach of our eyes, so that as there are several
+sorts of Insects, as Mites, and others, so small as not yet to have had any
+names; (some of which I shall afterwards describe) and small Fishes, as
+Leeches in Vineger; and smal vegetables, as Moss, and Rose-Leave-plants;
+and small Mushroms, as mould: so are there, it seems, small Shel-fish
+likewise, Nature shewing her curiosity in every Tribe of _Animals_,
+_Vegetables_, and _Minerals_.
+
+I was trying several small and single Magnifying Glasses, and casually
+viewing a parcel of white Sand, when I perceiv'd one of the grains exactly
+shap'd and wreath'd like a Shell, but endeavouring to distinguish it with
+my naked eye, it was so very small, that I was fain again to make use of
+the Glass to find it; then, whilest I thus look'd on it, with a Pin I
+separated all the rest of the granules of Sand, and found it afterwards to
+appear to the naked eye an exceeding small white spot, no bigger than the
+point of a Pin. Afterwards I view'd it every way with a better _Microscope_
+and found it on both sides, and edge-ways, to resemble the Shell of a small
+Water-Snail with a flat spiral Shell: it had twelve wreathings, a, b, c, d,
+e, &c. all very proportionably growing one less than another toward the
+middle or center of the Shell, where there was a very small round white
+spot. I could not certainly discover whether the Shell were hollow or not,
+but it seem'd fill'd with somewhat, and 'tis probable that it might be
+_petrify'd_ as other larger Shels often are, such as are mention'd in the
+seventeenth _Observation_.
+
+       *       *       *       *       *
+
+
+Observ. XII. _Of _Gravel_ in Urine._
+
+I Have often observ'd the Sand or Gravel of Urine, which seems to be a
+_tartareous_ substance, generated out of a _saline_ and a _terrestrial_
+substance _crystalliz'd_ together, in the form of _Tartar_, sometimes
+sticking to the sides of the _Urinal_, but for the most part sinking to the
+bottom, and there lying in the form of coorse common Sand; these, through
+the _Microscope_, appear to be a company of small bodies, partly
+transparent and partly _opacous_, some White, some Yellow, some Red, others
+of more brown and duskie colours.
+
+The Figure of them is for the most part flat, in the manner of Slats or
+such like plated Stones, that is, each of them seem to be made up of
+several other thinner Plates, much like _Muscovie Glass_, or _Englsh Sparr_
+to the last of which, the white plated Gravel seems most likely; for they
+seem not onely plated like that, but their sides shap'd also into _Rhombs_,
+_Rhomboeids_, and sometimes into _Rectangles_ and _Squares_. Their bigness
+and Figure may be seen in the second _Figure_ of the seventh _Plate_, which
+represents about a dozen of them lying upon a plate ABCD, some of which, as
+a, b, c, d seem'd more regular than the rest, and e, which was a small one,
+sticking on the top of another, was a perfet _Rhomboeid_ on the top, and
+had four _Rectangular_ sides.
+
+The line E which was the the measure of the _Microscope_, is 1/32 part of
+an _English_ Inch, so that the greatest bredth of any of them, exceeded not
+1/128 part of an Inch.
+
+Putting these into several liquors, I found _oyl of Vitriol_, _Spirit of
+Urine_, and several other _Saline menstruums_ to dissolve them; and the
+first of these in less than a minute without _Ebullition_, Water, and
+several other liquors, had no sudden operation upon them. This I mention,
+because those liquors that dissolve them, first make them very white, not
+_vitiating_, but rather rectifying their Figure, and thereby make them
+afford a very pretty object for the _Microscope_.
+
+How great an advantage it would be to such as are troubled with the Stone,
+to find some _menstruum_ might dissolve them without hurting the Bladder,
+is easily imagin'd, since some _injections_ made of such bodies might
+likewise dissolve the stone, which seems much of the same nature.
+
+It may therefore, perhaps, be worthy some Physicians enquiry, whether there
+may not be something mixt with the Urine in which the Gravel or Stone lies,
+which may again make it dissolve it, the first of which seems by it's
+regular Figures to have been sometimes _Crystalliz'd_ out of it. For
+whether this _Crystallization_ be made in the manner as _Alum_, _Peter_,
+&c. are _crystallized_ out of a cooling liquor, in which, by boyling they
+have been dissolv'd; or whether it be made in the manner of _Tartarum
+Vitriolatum_, that is, by the _Coalition_ of an _acid_ and a _Sulphureous_
+substance, it seems not impossible, but that the liquor it lies in, may be
+again made a _dissolvent_ of it. But leaving these inquiries to Physicians
+or Chymists, to whom it does more properly belong, I shall proceed.
+
+       *       *       *       *       *
+
+
+Observ. XIII. _Of the small _Diamants_, or _Sparks_ in _Flints_._
+
+Chancing to break a Flint stone in pieces, I found within it a certain
+cavity all crusted over with a very pretty candied substance, some of the
+parts of which, upon changing the posture of the Stone, in respect of the
+_Incident_ light, exhibited a number of small, but very vivid reflections;
+and having made use of my _Microscope_, I could perceive the whole surface
+of that cavity to be all beset with a multitude of little _Crystaline_ or
+_Adamantine_ bodies, so curiously shap'd, that it afforded a not unpleasing
+object.
+
+Having considered those vivid _repercussions_ of light, I found them to be
+made partly from the plain external surface of these regularly figured
+bodies (which afforded the vivid reflexions) and partly to be made from
+within the somewhat _pellucid_ body, that is, from some surface of the
+body, opposite to that superficies of it which was next the eye.
+
+And because these bodies were so small, that I could not well come to make
+Experiments and Examinations of them, I provided me several small _stiriae_
+of Crystals or Diamants, found in great quantities in _Cornwall_ and are
+therefore commonly called _Cornish Diamants_: these being very _pellucid_,
+and growing in a hollow cavity of a Rock (as I have been several times
+informed by those that have observ'd them) much after the same manner as
+these do in the Flint, and having besides their outward surface very
+regularly shap'd, retaining very near the same Figures with some of those I
+observ'd in the other, became a convenient help to me for the Examination
+of the proprieties of those kinds of bodies.
+
+And first for the Reflections, in these I found it very observable, That
+the brightest reflections of light proceeded from within the _pellucid_
+body; that is, that the Rays admitted through the _pellucid_ substance in
+their getting out on the opposite side, were by the contiguous and strong
+reflecting surface of the Air very vividly reflected, so that more Rays
+were reflected to the eye by this surface, though the Ray in entring and
+getting out of the Crystal had suffer'd a double refraction, than there
+were from the outward surface of the Glass where the Ray had suffer'd no
+reflection at all.
+
+And that this was the surface of the Air that gave so vivid a
+_re-percussion_ I try'd by this means I sunk half of a _stiria_ in Water,
+so that only Water was contiguous to the under surface, and then the
+internal reflection was so exceedingly faint, that it was scarce
+discernable. Again, I try'd to alter this vivid reflection by keeping off
+the Air, with a body not fluid, and that was by rubbing and holding my
+finger very hard against the under surface, so as in many places the pulp
+of my finger did touch the Glass, without any _interjacent_ air between,
+then observing the reflection, I found, that wheresoever my finger or skin
+toucht the surface, from that part there was no reflection, but in the
+little furrows or creases of my skin, where there remain'd little small
+lines of air, from them was return'd a very vivid reflection as before. I
+try'd further, by making the surface of very pure Quicksilver to be
+contiguous to the under surface of this _pellucid_ body, and then the
+reflection from that was so exceedingly more vivid than from the air, as
+the reflection from air was than the reflection from the Water; from all
+which trials I plainly saw, that the strong reflecting air was the cause of
+this _Phaenomenon_.
+
+And this agrees very well with the _Hypothesis_ of light and _Pellucid_
+bodies which I have mention'd in the description of _Muscovy-glass_; for we
+there suppose Glass to be a _medium_, which does less resist the pulse of
+light, and consequently, that most of the Rays incident on it enter into
+it, and are refracted towards the _perpendicular_; whereas the air I
+suppose to be a body that does more resist it, and consequently more are
+_re-percuss'd_ then do enter it: the same kind of trials have I made, with
+_Crystalline Glass_, with drops of fluid bodies, and several other ways,
+which do all seem to agree very exactly with this _Theory_. So that from
+this Principle well establish'd, we may deduce severall Corollaries not
+unworthy observation.
+
+And the first is; that it plainly appears by this, that the production of
+the Rainbow is as much to be ascribed to the reflection of the concave
+surface of the air, as to the refraction of the _Globular_ drops: this will
+be evidently manifest by these Experiments, if you _foliate_ that part of a
+Glass-ball that is to reflect an _Iris_, as in the _Cartesian_ Experiment,
+above mention'd, the reflections will be abundantly more strong, and the
+colours more vivid: and if that part of the surface be touch'd with Water,
+scarce affords any sensible colour at all.
+
+Next we learn, that the great reason why _pellucid_ bodies beaten small are
+white, is from the multitude of reflections, not from the particles of the
+body, but from the _contiguous_ surface of the air. And this is evidently
+manifested, by filling the _Interstitia_ of those powder'd bodies with
+Water, whereby their whiteness presently disappears. From the same reason
+proceeds the whiteness of many kinds of Sands, which in the _Microscope_
+appear to be made up of a multitude of little _pellucid_ bodies, whose
+brightest reflections may by the _Microscope_ be plainly perceiv'd to come
+from their internal surfaces; and much of the whiteness of it may be
+destroy'd by the affusion of fair Water to be contiguous to those surfaces.
+
+The whiteness also of froth, is for the most part to be ascribed to the
+reflection of the light from the surface of the air within the Bubbles, and
+very little to the reflection from the surface of the Water it self: for
+this last reflection does not return a quarter so many Rays, as that which
+is made from the surface of the air, as I have certainly found by a
+multitude of Observations and Experiments.
+
+The whiteness of _Linnen_, _Paper_, _Silk_, &c. proceeds much from the same
+reason, as the _Microscope_ will easily discover; for the Paper is made up
+of an abundance of _pellucid_ bodies, which afford a very plentifull
+reflection from within, that is, from the concave surface of the air
+contiguous to its component particles; wherefore by the affusion of Water,
+Oyl, Tallow, Turpentine, &c. all those reflections are made more faint, and
+the beams of light are suffer'd to traject & run through the Paper more
+freely.
+
+Hence further we may learn the reason of the whiteness of many bodies, and
+by what means they maybe in part made _pellucid_: As white Marble for
+instance, for this body is composed of a _pellucid_ body exceedingly
+flaw'd, that is, there are abundance of thin, and very fine cracks or
+chinks amongst the multitude of particles of the body, that contain in them
+small parcels of air, which do so _re-percuss_ and drive back the
+penetrating beams, that they cannot enter very deep within that body; which
+the _Microscope_ does plainly inform us to be made up of a _Congeries_ of
+_pellucid_ particles. And I further found it somewhat more evidently by
+some attempts I made towards the making transparent Marble, for by heating
+the Stone a little, and baking it in Oyl, Turpentine, Oyl of Turpentine,
+&c., I found that I was able to see much deeper into the body of Marble
+then before; and one trial, which was not with an unctuous substance,
+succeeded better than the rest, of which, when I have a better opportunity,
+I shall make further trial.
+
+This also gives us a probable reason of the so much admired _Phaenomena_,
+of the _Oculus Mundi_, an _Oval_ stone, which commonly looks like white
+Alabaster, but being laid a certain time in Water, it grows _pellucid_, and
+transparent, and being suffer'd to lie again dry, it by degrees loses that
+transparency, and becomes white as before. For the Stone being of a hollow
+spongie nature, has in the first and last of these appearances, all those
+pores fill'd with the obtunding and reflecting air; whereas in the second,
+all those pores are fill'd with a _medium_ that has much the same
+refraction with the particles of the Stone, and therefore those two being
+_contiguous_, make, as 'twere, one _continued medium_, of which more is
+said in the 15. _Observation_.
+
+There are a multitude of other _Phaenomena_, that are produc'd from this
+same Principle, which as it has not been taken notice of by any yet that I
+know, so I think, upon more diligent observation, will it not be found the
+least considerable. But I have here onely time to hint _Hypotheses_, and
+not to prosecute them so fully as I could wish; many of them having a vast
+extent in the production of a multitude of _Phaenomena_, which have been by
+others, either not attempted to be explain'd, or else attributed to some
+other cause than what I have assign'd, and perhaps than the right; and
+therefore I shall leave this to the prosecution of such as have more
+leisure: onely before I leave it, I must not pretermit to hint, that by
+this Principle, multitudes of the _Phaenomena_ of the air, as about
+_Mists_, _Clouds_, _Meteors_, _Haloes_, &c. are most plainly and (perhaps)
+truly explicable; multitudes also of the _Phaenomena_ in colour'd bodies,
+as liquors, &c. are deducible from it.
+
+And from this I shall proceed to a second considerable _Phaenomenon_ which
+these Diamants exhibit, and that is the regularity of their _Figure_, which
+is a propriety not less general than the former, It comprising within its
+extent, all kinds of _Metals_, all kinds of _Minerals_, most _Precious
+stones_, all kinds of _Salts_, multitudes of _Earths_, and almost all kinds
+of _fluid bodies_. And this is another propiety, which, though a little
+superficially taken notice of by some, has not, that I know, been so much
+as attempted to be explicated by any.
+
+This propriety of bodies, as I think it the most worthy, and next in order
+to be consider'd after the contemplation of the _Globular Figure_, so have
+I long had a desire as wel as a determination to have prosecuted it if I
+had had an opportunity, having long since propos'd to my self the method of
+my enquiry therein, it containing all the allurements that I think any
+enquiry is capable of: For, first I take it to proceed from the most simple
+principle that any kind of form can come from, next the _Globular_, which
+was therefore the first I set upon, and what I have therein perform'd, I
+leave the Judicious Reader to determine. For as that form proceeded from a
+propiety of fluid bodies, which I have call'd _Congruity_, or
+_Incongruity_; so I think, had I time and opportunity, I could make
+probable, that all these regular Figures that are so conspicuously
+_various_ and _curious_, and do so adorn and beautifie such multitudes of
+bodies, as I have above hinted, arise onely from three or four several
+positions or postures of _Globular_ particles, and those the most plain,
+obvious, and necessary conjunctions of such figur'd particles that are
+possible, so that supposing such and such plain and obvious causes
+concurring the _coagulating particles_ must necessarily compose a body of
+such a determinate regular Figure, and no other, and this with as much
+necessity and obviousness as a fluid body encompast with a _Heterogeneous_
+fluid must be protruded into a _Spherule_ or _Globe_. And this I have _ad
+oculum_ demonstrated with a company of bullets, and some few other very
+simple bodies; so that there was not any regular Figure, which I have
+hitherto met withall, of any of those bodies that I have above named, that
+I could not with the composition of bullets or globules, and one or two
+other bodies, imitate, even almost by shaking them together. And thus for
+instance may we find that the _Globular_ bullets will of themselves, if put
+on an inclining plain, so that they may run together, naturally run into a
+_triangular_ order, composing all the variety of figures that can be
+imagin'd to be made out of _aequilateral triangles_; and such will you
+find, upon trial, all the Surfaces of _Alum_ to be compos'd of: For three
+bullets lying on a plain, as close to one another as they can compose an
+_aequilatero-triangular_ form, as in A in the 7. _Scheme_. If a fourth be
+joyn'd to them on either side as closely as it can, they four compose the
+most regular Rhombus consisting of two _aequilateral triangles_, as B. If a
+fifth be joyn'd to them on either side in as close a position as it can,
+which is the propriety of the _Texture_, it makes a _Trapezium_, or
+four-sided Figure, two of whole angles are 120. and two 60. degrees, as C.
+If a sixth be added, as before, either it makes an _aequilateral triangle_,
+as D, or a Rhomboeid, as E, or an _Hex-angular Figure_, as F, which is
+compos'd of two _primary Rhombes_. If a seventh be added, it makes either
+an _aequilatero-hexagonal_ Figure, as G, or some kind of six-sided
+_Figure_, as H, or I. And though there be never so many placed together,
+they may be rang'd into some of these lately mentioned Figures, all the
+angles of which will be either _60_. degrees, or 120. as the figure K.
+which is an _aequiangular hexagonal_ Figure is compounded of 12.
+_Globules_, or may be of 25, or 27, or 36, or 42, &c. and by these kinds of
+texture, or position of globular bodies, may you find out all the variety
+of regular shapes, into which the smooth surfaces of _Alum_ are form'd, as
+upon examination any one may easily find; nor does it hold only in
+superficies, but in solidity also, for it's obvious that a fourth _Globule_
+laid upon the third in this texture, composes a regular _Tetrahedron_,
+which is a very usual Figure of the _Crystals_ of _Alum_. And (to hasten)
+there is no one Figure into which _Alum_ is observ'd to be crystallized,
+but may by this texture of _Globules_ be imitated, and by no other.
+
+I could instance also in the Figure of _Sea-salt_, and _Sal-gem_, that it
+is compos'd of a texture of _Globules_, placed in a _cubical_ form, as L,
+and that all the Figures of those Salts may be imitated by this texture of
+_Globules_ and by no other whatsoever. And that the forms of _Vitriol_ and
+of _Salt-Peter_, as also of _Crystal_, _Hore-frost_, &c. are compounded of
+these two textures, but modulated by certain proprieties: But I have not
+here time to insist upon, as I have not neither to shew by what means
+_Globules_ come to be thus context, and what those _Globules_ are, and many
+other particulars requisite to a full and intelligible explication of this
+propriety of bodies. Nor have I hitherto found indeed an opportunity of
+prosecuting the inquiry so farr as I design'd; nor do I know when I may, it
+requiring abundance of time, and a great deal of assistance to go through
+with what I design'd; the model of which was this:
+
+First, to get as exact and full a collection as I could, of all the
+differing kinds of Geometrical figur'd bodies, some three or four several
+bodies of each kind.
+
+Secondly, with them to get as exact a History as possibly I could learn of
+their places of Generation or finding, and to enquire after as many
+circumstances that tended to the Illustrating of this Enquiry, as possibly
+I could observe.
+
+Thirdly, to make as many trials as upon experience I could find requisite,
+in Dissolutions and Coagulations of several crystallizing Salts; for the
+needfull instruction and information in this Enquiry.
+
+Fourthly, to make several trials on divers other bodies, as Metals,
+Minerals, and Stones, by dissolving them in several _Menstruums_, and
+crystalizing them, to see what Figures would arise from those several
+_Compositums_.
+
+Fifthly, to make Compositions and Coagulations of several Salts together
+into the same mass, to observe of what Figure the product of them would be;
+and in all, to note as many circumstances as I should judge conducive to my
+Enquiry.
+
+Sixthly, to enquire the closeness or rarity of the texture of these bodies,
+by examining their gravity, and their refraction, &c.
+
+Seventhly, to enquire particularly what operations the fire has upon
+several kinds of Salts, what changes it causes in their Figures, Textures,
+or Energies.
+
+Eighthly, to examine their manner of dissolution, or acting upon those
+bodies dissoluble in them; The texture of those bodies before and after the
+process. And this for the History.
+
+Next for the Solution, To have examin'd by what, and how many means, such
+and such Figures, actions and effects could be produc'd possibly.
+
+And lastly, from all circumstances well weigh'd, I should have endeavoured
+to have shewn which of them was most likely, and (if the informations by
+these Enquiries would have born it) to have demonstrated which of them it
+must be, and was.
+
+But to proceed, As I believe it next to the Globular the most simple; so do
+I, in the second place, judge it not less pleasant; for that which makes an
+Enquiry pleasant, are, first a noble _Inventum_ that promises to crown the
+successfull endeavour; and such must certainly the knowledge of the
+efficient and concurrent causes of all these curious Geometrical Figures
+be, which has made the Philosophers hitherto to conclude nature in these
+things to play the Geometrician, according to that saying of _Plato_,
+[Greek: Ho Theos geometrei]. Or next, a great variety of matter in the
+Enquiry; and here we meet with nothing less than the _Mathematicks_ of
+nature, having every day a new Figure to contemplate, or a variation of the
+same in another body,
+
+Which do afford us a third thing, which will yet more sweeten the Enquiry,
+and that is, a multitude of information; we are not so much to grope in the
+dark, as in most other Enquiries, where the _Inventum_ is great; for having
+such a multitude of instances to compare, and such easie ways of
+generating, or compounding and of destroying the form, as in the _Solution_
+and _Crystallization_ of Salts, we cannot but learn plentifull information
+to proceed by. And this will further appear from the universality of the
+Principle which Nature has made use of almost in all inanimate bodies. And
+therefore, as the contemplation of them all conduces to the knowledg of any
+one; so from a Scientifical knowledge of any one does follow the fame of
+all, and every one.
+
+And fourthly, for the usefulness of this knowledge, when acquir'd;
+certainly none can doubt, that considers that it caries us a step forward
+into the Labirinth of Nature, in the right way towards the end we propose
+our selves in all Philosophical Enquiries. So that knowing what is the form
+of Inanimate or Mineral bodies, we shall be the better able to proceed in
+our next Enquiry after the forms of Vegetative bodies; and last of all, of
+Animate ones, that seeming to be the highest step of natural knowledge that
+the mind of man is capable of.
+
+       *       *       *       *       *
+
+
+Observ. XIV. _Of several kindes of frozen _Figures_._
+
+I have very often in a Morning, when there has been a great _hoar-frost_,
+with an indifferently magnifying _Microscope_, observ'd the small
+_Stiriae_, or Crystalline beard, which then usually covers the face of
+most bodies that lie open to the cold air, and found them to be generally
+_Hexangular prismatical_ bodies, much like the long Crystals of
+_Salt-peter_, save onely that the ends of them were differing: for whereas
+those of _Nitre_ are for the most part _pyramidal_, being terminated either
+in a point or edge; these of Frost were hollow, and the cavity in some
+seem'd pretty deep, and this cavity was the more plainly to be seen,
+because usually one or other of the six _parallelogram_ sides was wanting,
+or at least much shorter then the rest.
+
+But this was onely the Figure of the _Bearded hoar-frost_; and as for the
+particles of other kinds of _hoar-frosts_, they seem'd for the most part
+irregular, or of no certain Figure. Nay, the parts of those curious
+branchings, or _vortices_, that usually in cold weather tarnish the surface
+of Glass, appear through the _Microscope_ very rude and unshapen, as do
+most other kinds of frozen _Figures_, which to the naked eye seem exceeding
+neat and curious, such as the Figures of _Snow_, frozen _Urine_, _Hail_,
+several _Figures_ frozen in common Water, &c. Some Observations of each of
+which I shall hereunto annex, because if well consider'd and examin'd, they
+may, perhaps, prove very instructive for the finding out of what I have
+endeavoured in the preceding Observation to shew, to be (next the _Globular
+Figure_ which is caus'd by _congruity_, as I hope I have made probable in
+the sixth _Observation_) the most simple and plain operation of Nature, of
+which, notwithstanding we are yet ignorant.
+
+I.
+
+_Several Observables in the _six-branched_ Figures form'd on the surface of
+Urine by freezing._
+
+1 [11]The Figures were all frozen almost even with the surface of the
+_Urine_ in the Vessel; but the bigger stems were a little _prominent_ above
+that surface, and the parts of those stems which were nearest the center
+(a) were biggest above the surface.
+
+2 I have observ'd several kinds of these Figures, some smaller, no bigger
+then a Two-pence, others so bigg, that I have by measure found one of its
+stems or branches above four foot long; and of these, some were pretty
+round, having all their branches pretty neer alike; other of them were more
+extended towards one side, as usually those very large ones were, which I
+have observ'd in Ditches which have been full of foul water.
+
+3 None of all these Figures I have yet taken notice of, had any regular
+position in respect of one another, or of the sides of the Vessel; nor did
+I find any of them equally to exactness extended every way from the center
+a.
+
+4 Where ever there was a center, the branchings from it, ab, ac, ad, ae,
+af, ag, were never fewer, or more then six, which usually concurr'd, or met
+one another very neer in the same point or center, a; though oftentimes not
+exactly; and were enclin'd to each other by an angle, of very near sixty
+degrees, I say, very neer, because, though having endeavoured to measure
+them the most acurately I was able, with the largest Compasses I had, I
+could not find any sensible variation from that measure, yet the whole
+six-branched Figure seeming to compose a solid angle, they must necessarily
+be somewhat less.
+
+5 The middle lines or stems of these branches, ab, ac, ad, ae, af, ag,
+seem'd somewhat whiter, and a little higher then any of the _intermediate_
+branchings of these Figures; and the center a, was the most _prominent_
+part of the whole Figure, seeming the _apex_ of a solid angle or _pyramid_,
+each of the six plains being a little enclin'd below the surface of the
+_Urin_.
+
+6 The lateral branchings issuing out of the great ones, such as op, mq, &c.
+were each of them inclin'd to the great ones, by the same angle of about
+sixty degrees, as the great ones were one to another, and always the bigger
+branchings were _prominent_ above the less, and the less above the least,
+by proportionate _gradations_.
+
+7 The _lateral_ branches shooting out of the great ones, went all of them
+from the center, and each of them was parallel to that great branch, next
+to which it lay; so that as all the branches on one side were parallel to
+one another, so were they all of them to the _approximate_ great branch, as
+po, qr, as they were parallel to each other, and shot from the center, so
+were they parallel also to the great branch ab.
+
+8 Some of the stems of the six branches proceeded straight, and of a
+thickness that gradually grew sharper towards the end, as ag.
+
+9 Others of the stems of those branches grew bigger and knotty towards the
+middle, and the branches also as well as stems, from Cylinders grew into
+Plates, in a most admirable and curious order, so exceeding regular and
+delicate, as nothing could be more, as is visible in ab, ac, ad, ae, af,
+but towards the end of some of these stems, they began again to grow
+smaller and to recover their former branchings, as about k and n.
+
+10 Many of the _lateral_ branches had _collateral_ branches (if I may so
+call them) as qm had many such as st, and most of those again
+_subcollateral_, as vw, and these again had others less, which one may call
+_laterosubcollateral_, and these again others, and they others, &c. in
+greater Figures.
+
+11 The branchings of the main Stems joyn'd not together by any regular
+line, nor did one side of the one lie over the other side of the other, but
+the small _collateral_ and _subcollateral_ branches did lie at top of one
+another according to a certain order or method, which I always observ'd to
+be this.
+
+12 That side of a _collateral_ or _subcollateral_, &c. branch, lay over the
+side of the _approximate_ (as the feathers in the wing of a Bird) whose
+branchings proceeded parallel to the last biggest stem from which it
+sprung, and not to the biggest stem of all, unless that were a second stem
+backwards.
+
+13 This rule that held in the branchings of the _Sexangular Figure_ held
+also in the branchings of any other great or small stem, though it did not
+proceed from a center.
+
+14 The exactness and curiosity of the figuration of these branches, was in
+every particular so transcendent, that I judge it almost impossible for
+humane art to imitate.
+
+15 Tasting several cleer pieces of this _Ice_, I could not find any
+_Urinous_ taste in them, but those few I tasted, seem'd as _insipid_ as
+water.
+
+16 A figuration somewhat like this, though indeed in some particulars much
+more curious, I have several times observ'd in _regulus martis stellatus_,
+but with this difference, that all the stems and branchings are bended in a
+most excellent and regular order, whereas in _Ice_ the stems and branchings
+are streight, but in all other particulars it agrees with this, and seems
+indeed nothing but one of these stars, or branched Figures frozen on
+_Urine_, distorted, or wreathed a little, with a certain proportion: _Lead_
+also that has _Arsenick_ and some other things mixt with it, I have found
+to have its surface, when suffer'd to cool, figured somewhat like the
+branchings of _Urine_, but much smaller.
+
+17 But there is a _Vegetable_ which does exceedingly imitate these
+branches, and that is, _Fearn_, where the main stem may be observ'd to
+shoot out branches, and the stems of each of these _lateral_ branches, to
+send forth _collateral_, and those _subcollateral_ and those
+_laterosubcollateral,_ &c. and all those much after the same order with the
+branchings, divisions, and subdivisions in the branchings of these Figures
+in frozen _Urine_; so that if the Figures of both be well consider'd, one
+would ghess that there were not much greater need of a _seminal principle_
+for the production of _Fearn_, then for the production of the branches of
+_Urine_, or the _Stella martis_, there seeming to be as much form and
+beauty in the one as in the other.
+
+And indeed, this Plant of _Fearn_, if all particulars be well consider'd,
+will seem of as simple, and uncompounded a form as any _Vegetable_, next to
+_Mould_ or _Mushromes_, and would next after the invention of the forms of
+those, deserve to be enquir'd into; for notwithstanding several have
+affirm'd it to have seed, and to be propagated thereby; yet, though I have
+made very diligent enquiry after that particular, I cannot find that there
+is any part of it that can be imagin'd to be more seminal then another: But
+this onely here by the by:
+
+For the freezing Figures in _Urine_, I found it requisite,
+
+First, that the Superficies be not disturbed with any wind, or other
+commotion of the air, or the like.
+
+Secondly, that it be not too long exposed, so as that the whole bulk be
+frozen, for oftentimes, in such cases, by reason of the swelling the of
+_Ice_, or from some other cause, the curious branched Figures disappear.
+
+Thirdly, an artificial freezing with _Snow_ and _Salt_, apply'd to the
+outside of the containing Vessel, succeeds not well, unless there be a very
+little quantity in the Vessel.
+
+Fourthly, If you take any cleer and smooth Glass, and wetting all the
+inside of it with _Urine_, you expose it to a very sharp freezing, you will
+find it cover'd with a very regular and curious Figure.
+
+II.
+
+_Observables in figur'd _Snow_._
+
+Exposing a piece of black Cloth, or a black Hatt to the falling _Snow_, I
+have often with great pleasure, observ'd such an infinite variety of
+curiously figur'd _Snow_, that it would be as impossible to draw the Figure
+and shape of every one of them, as to imitate exactly the curious and
+Geometrical _Mechanisme_ of Nature in any one. Some coorse draughts, such
+as the coldness of the weather, and the ill provisions, I had by me for
+such a purpose, would permit me to make, I have here added in the Second
+_Figure_ of the Eighth _Scheme_.[12]
+
+In all which I observ'd, that if they were of any regular Figures, they
+were always branched out with six principal branches, all of equal length,
+shape and make, from the center, being each of them inclin'd to either of
+the next branches on either side of it, by an angle of sixty degrees.
+
+Now, as all these stems were for the most part in one flake exactly of the
+same make, so were they in differing Figures of very differing ones; so
+that in a very little time I have observ'd above an hundred several cizes
+and shapes of these starry flakes.
+
+The branches also out of each stem of any one of these flakes, were exactly
+alike in the same flake; so that of whatever Figure one of the branches
+were, the other five were sure to be of the same, very exactly, that is, if
+the branchings of the one were small _Perallelipipeds_ or Plates, the
+branchings of the other five were of the same; and generally, the
+branchings were very conformable to the rules and method observ'd before,
+in the Figures on _Urine_, that is, the branchings from each side of the
+stems were parallel to the next stem on that side, and if the stems were
+plated, the branches also were the same; if the stems were very long, the
+branches also were so, &c.
+
+Observing some of these figur'd flakes with a _Microscope_, I found them
+not to appear so curious and exactly figur'd as one would have imagin'd,
+but like Artificial Figures, the bigger they were magnify'd, the more
+irregularites appear'd in them; but this irregularity seem'd ascribable to
+the thawing and breaking of the flake by the fall, and not at all to the
+defect of the _plastick_ virtue of Nature, whose curiosity in the formation
+of most of these kind of regular Figures, such as those of _Salt_,
+_Minerals_, &c. appears by the help of the _Microscope_, to be very many
+degrees smaller then the most acute eye is able to perceive without it. And
+though one of these six-branched Stars appear'd here below much of the
+shape described in the Third _Figure_ of the Eighth _Scheme_; yet I am very
+apt to think, that could we have a sight of one of them through a
+_Microscope_ as they are generated in the Clouds before their Figures are
+vitiated by external accidents, they would exhibit abundance of curiosity
+and neatness there also, though never so much magnify'd: For since I have
+observ'd the Figures of _Salts_ and _Minerals_ to be some of them so
+exceeding small, that I have scarcely been able to perceive them with the
+_Microscope_, and yet have they been regular, and since (as far as I have
+yet examin'd it) there seems to be but one and the same cause that produces
+both these effects, I think it not irrational to suppose that these pretty
+figur'd Stars of _Snow_, when at first generated might be also very regular
+and exact.
+
+III.
+
+_Several kinds of Figures in _Water_ frozen._
+
+Putting fair Water into a large capacious Vessel of _Glass_, and exposing
+it to the cold, I observ'd after a little time, several broad, flat, and
+thin _laminae_, or plates of _Ice_, crossing the bulk of the water and one
+another very irregularly, onely most of them seem'd to turn one of their
+edges towards that side of the Glass which was next it, and seem'd to grow,
+as 'twere from the inside of the Vessel inwards towards the middle, almost
+like so many blades of _Fern_. Having taken several of these plates out of
+water on the blade of a Knife, I observ'd them figur'd much after the
+manner of _Herring bones_, or _Fern blades_, that is, there was one bigger
+stem in the middle like the back-bone, and out of it, on either side, were
+a multitude of small _stiriae_, or _icicles_, like the smaller bones, or
+the smaller branches in _Fern_, each of these branches on the one side,
+were parallel to all the rest on the same side, and all of them seem'd to
+make an angle with the stem, towards the top, of sixty degrees, and towards
+the bottom or root of this stem, of 120. See the fourth _Figure_ of the 8.
+_Plate_.
+
+I observ'd likewise several very pretty Varieties of Figures in Water,
+frozen on the top of a broad flat Marble-stone, expos'd to the cold with a
+little Water on it, some like feathers, some of other shapes, many of them
+were very much of the shape exprest in the fifth Figure of the 8. _Scheme_,
+which is extremely differing from any of the other Figures.
+
+I observ'd likewise, that the shootings of _Ice_ on the top of Water,
+beginning to freez, were in streight _prismatical_ bodies much like those
+of _roch-peter_, that they crost each other usually without any kind of
+order or rule, that they were always a little higher then the surface of
+the Water that lay between them; that by degrees those _interjacent_ spaces
+would be fill'd with _Ice_ also, which usually would be as high as the
+surface of the rest.
+
+In flakes of _Ice_ that had been frozen on the top of Water to any
+considerable thickness, I observ'd that both the upper and the under sides
+of it were curiously quill'd, furrow'd, or grain'd, as it were, which when
+the Sun shone on the Plate, was exceeding easily to be perceiv'd to be much
+after the shape of the lines in the 6. _Figure_ of the 8. _Scheme_, that
+is, they consisted of several streight ends of parallel Plates, which were
+of divers lengths and angles to one another without any certain order.
+
+The cause of all which regular Figures (and of hundreds of others, namely
+of _Salts_, _Minerals_, _Metals,_ &c. which I could have here inserted,
+would it not have been too long) seems to be deducible from the same
+Principles, which I have (in the 13. _Observation_) hinted only, having not
+yet had time to compleat a _Theory_ of them. But indeed (which I there also
+hinted) I judge it the second step by which the _Pyramid_ of natural
+knowledge (which is the knowledge of the form of bodies) is to be ascended:
+And whosoever will climb it, must be well furnish'd with that which the
+Noble _Verulam_ calls _Scalam Intellectus_; he must have scaling Ladders,
+otherwise the steps are so large and high, there will be no getting up
+them, and consequently little hopes of attaining any higher station, such
+as to the knowledge of the most simple principle of Vegetation manifested
+in Mould and Mushromes, which, as I elsewhere endeavoured to shew, seems to
+be the third step; for it seems to me, that the Intellect of man is like
+his body, destitute of wings, and cannot move from a lower to a higher and
+more sublime station of knowledg, otherwise then step by step, nay even
+there where the way is prepar'd and already made passible; as in the
+_Elements of Geometry_, or the like, where it is fain to climb a whole
+_series_ of Propositions by degrees, before it attains the knowledge of one
+_Probleme_. But if the ascent be high, difficult and above its reach, it
+must have recourse to a _novum organum_, some new engine and contrivance,
+some new kind of _Algebra_, or _Analytick Art_ before it can surmount it.
+
+       *       *       *       *       *
+
+
+Observ. XV. _Of _Kettering-stone_, and of the pores of _Inanimate_ bodies._
+
+[13]This Stone which is brought from _Kettering_ in _Northampton-Shire_,
+and digg'd out of a Quarry, as I am inform'd, has a grain altogether
+admirable, nor have I ever seen or heard of any other stone that has the
+like. It is made up of an innumerable company of small bodies, not all of
+the same cize or shape, but for the most part, not much differing from a
+Globular form, nor exceed they one another in Diameter above three or four
+times; they appear to the eye, like the Cobb or Ovary of a _Herring_, or
+some smaller fishes, but for the most part, the particles seem somewhat
+less, and not so uniform; but their variation from a perfect globular ball,
+seems to be only by the pressure of the _contiguous_ bals which have a
+little deprest and protruded those toucht sides inward, and forc'd the
+other sides as much outwards beyond the limits of a Globe; just as it would
+happen, if a heap of exactly round Balls of soft Clay were heaped upon one
+another; or, as I have often seen a heap of small Globules of
+_Quicksilver_, reduc'd to that form by rubbing it much in a glaz'd Vessel,
+with some slimy or sluggish liquor, such as Spittle, when though the top of
+the upper Globules be very neer spherical, yet those that are prest upon by
+others, exactly imitate the forms of these lately mention'd grains.
+
+Where these grains touch each other, they are so firmly united or settled
+together, that they seldom part without breaking a hole in one or th'other
+of them, such as a, a, a, b, c, c, &c. Some of which fractions, as a, a, a,
+a, where the touch has been but light, break no more then the outward
+crust, or first shell of the stone, which is of a white colour, a little
+dash'd with a brownish Yellow, and is very thin, like the shell of an Egg:
+and I have seen some of those grains perfectly resemble some kind of Eggs,
+both in colour and shape: But where the union of the _contiguous granules_
+has been more firm, there the divulsion has made a greater Chasm, as at b,
+b, b, in so much that I have observ'd some of them quite broken in two, as
+at c, c, c, which has discovered to me a further resemblance they have to
+Eggs, they having an appearance of a white and yelk, by two differing
+substances that envelope and encompass each other.
+
+That which we may call the white was pretty whitish neer the yelk, but more
+duskie towards the shell; some of them I could plainly perceive to be shot
+or radiated like a _Pyrites_ or _fire-stone_; the yelk in some I saw
+hollow, in others fill'd with a duskie brown and porous substance like a
+kind of pith.
+
+The small pores, or _interstitia_ eeee betwixt the Globules, I plainly saw,
+and found by other trials to be every way pervious to air and water, for I
+could blow through a piece of this stone of a considerable thickness, as
+easily as I have blown through a Cane, which minded me of the pores which
+_Des Cartes_ allow his _materia subtilis_ between the _aethereal_ globules.
+
+The object, through the _Microscope_, appears like a _Congeries_ or heap of
+Pibbles, such as I have often seen cast up on the shore, by the working of
+the Sea after a great storm, or like (in shape, though not colour) a
+company of small Globules of Quicksilver, look'd on with a _Microscope_,
+when reduc'd into that form by the way lately mentioned. And perhaps, this
+last may give some hint at the manner of the formation of the former: For
+supposing some _Lapidescent_ substance to be generated, or some way brought
+(either by some commixture of bodies in the Sea it self, or protruded in,
+perhaps, out of some _subterraneous_ caverns) to the bottom of the Sea, and
+there remaining in the form of a liquor like Quicksilver, _heterogeneous_
+to the ambient _Saline_ fluid, it may by the working and tumblings of the
+Sea to and fro be jumbled and comminuted into such Globules as may
+afterwards be hardned into Flints, the lying of which one upon another,
+when in the Sea, being not very hard, by reason of the weight of the
+incompassing fluid, may cause the undermost to be a little, though not
+much, varied from a globular Figure. But this only by the by.
+
+After what manner this _Kettering-stone_ should be generated I cannot
+learn, having never been there to view the place, and observe the
+circumstances; but it seems to me from the structure of it to be generated
+from some substance once more fluid, and afterwards by degrees growing
+harder, almost after the same manner as I supposed the generation of Flints
+to be made.
+
+But whatever were the cause of its curious texture, we may learn this
+information from it; that even in those things which we account vile, rude,
+and coorse, Nature has not been wanting to shew abundance of curiosity and
+excellent Mechanisme.
+
+We may here find a Stone by help of a _Microscope_, to be made up of
+abundance of small Balls, which do but just touch each other, and yet there
+being so many contacts, they make a firm hard mass, or a Stone much harder
+then Free-stone.
+
+Next, though we can by a _Microscope_ discern so curious a shape in the
+particles, yet to the naked eye there scarce appears any such thing; which
+may afford us a good argument to think, that even in those bodies also,
+whose _texture_ we are not able to discern, though help'd with
+_Microscopes_, there may be yet _latent_ so curious a _Schematisme_, that
+it may abundantly satisfie the curious searcher, who shall be so happy as
+to find some way to discover it.
+
+Next, we here find a Stone, though to the naked eye a very close one, yet
+every way perforated with innumerable pores, which are nothing else but the
+_interstitia_, between those multitudes of minute globular particles, that
+compose the bulk it self, and these pores are not only discover'd by the
+_Microscope_, but by this contrivance.
+
+I took a pretty large piece of this stone, and covering it all over with
+cement, save only at two opposite parts, I found my self able, by blowing
+in at one end that was left open, to blow my spittle, with which I had wet
+the other end, into abundance of bubbles, which argued these pores to be
+open and pervious through the whole stone, which affords us a very pretty
+instance of the porousness of some seemingly close bodies, of which kind I
+shall anon have occasion to subjoyn many more, tending to prove the same
+thing.
+
+I must not here omit to take notice, that in this body there is not a
+_vegetative_ faculty that should so contrive this structure for any
+peculiar use of _vegetation_ or growth, whereas in the other instances of
+vegetable porous bodies, there is an _anima_ or _forma informans_, that
+does contrive all the Structures and _Mechanismes_ of the constituting
+body, to make them subservient and usefull to the great Work or Function
+they are to perform. And so I ghess the pores in Wood, and other
+vegetables, in bones, and other Animal substances, to be as so many
+channels, provided by the Great and Alwise Creator, for the conveyance of
+appropriated juyces to particular parts. And therefore, that this may tend,
+or be pervious all towards one part, and may have impediments, as valves or
+the like, to any other; but in this body we have very little reason so
+suspect there should be any such design, for it is equally pervious every
+way, not onely forward, but backwards, and side-ways, and seems indeed much
+rather to be _Homogeneous_ or similar to those pores, which we may with
+great probability believe to be the channels of _pellucid_ bodies, not
+directed, or more open any one way, then any other, being equally pervious
+every way. And, according as these pores are more or greater in respect of
+the _interstitial_ bodies, the more transparent are the so constituted
+concretes; and the smaller those pores are, the weaker is the _Impulse_ of
+light communicated through them, though the more quick be the progress.
+
+Upon this Occasion, I hope it will not be altogether unseasonable, if I
+propound my conjectures and _Hypothesis_ about the _medium_ and conveyance
+of light.
+
+I suppose then, that the greatest part of the _Interstitia_ of the world,
+that lies between the bodies of the Sun and Starrs, and the Planets, and
+the Earth, to be an exceeding fluid body, very apt and ready to be mov'd,
+and to communicate the motion of any one part to any other part, though
+never so far distant: Nor do I much concern my self, to determine what the
+Figure of the particles of this exceedingly subtile fluid _medium_ must be,
+nor whether it have any interstitiated pores or vacuities, it being
+sufficient to solve all the _Phaenomena_ to suppose it an exceedingly
+fluid, or the most fluid body in the world, and as yet impossible to
+determine the other difficulties.
+
+That being so exceeding fluid a body, it easily gives passage to all other
+bodies to move to and fro in it.
+
+That it neither receives from any of its parts, or from other bodies; nor
+communicates to any of its parts, or to any other body, any impulse, or
+motion in a direct line, that is not of a determinate quickness. And that
+when the motion is of such determinate swiftness, it both receives, and
+communicates, or propagates an impulse or motion to any imaginable distance
+in streight lines, with an unimaginable celerity and vigour.
+
+That all kind of solid bodies consist of pretty massie particles in respect
+of the particles of this fluid _medium_, which in many places do so touch
+each other, that none of this fluid _medium_ interposes much after the same
+mannner (to use a gross similitude) as a heap of great stones compose one
+great _congeries_ or mass in the midst of the water.
+
+That all fluid bodies which we may call _tangible_, are nothing but some
+more subtile parts of those particles, that serve to constitute all
+_tangible_ bodies.
+
+That the water, and such other fluid bodies, are nothing but a _congeries_
+of particles agitated or made fluid by it in the same manner as the
+particles of _Salt_ are agitated or made fluid by a parcel of water, in
+which they are dissolv'd, and subsiding to the bottom of it, constitute a
+fluid body, much more massie and dense, and less fluid then the pure water
+it self.
+
+That the air on the other side is a certain company of particles of quite
+another kind, that is, such as are very much smaller, and more easiely
+moveable by the motion of this fluid _medium_; much like those very subtile
+parts of _Cochenel_, other very deep tinging bodies, where by a very small
+parcel of matter is able to tinge and diffuse it self over a very great
+quantity of the fluid dissolvent; or somewhat after that manner, as smoak,
+and such like minute bodies, or steams, are observ'd to tinge a very great
+quantity of air; onely this last similitude is deficient in one propriety,
+and that is a perpetuity or continuance in that state of commixture with
+the air, but the former does more neerly approach to the nature and manner
+of the air's being dissolv'd by this fluid or _AEther_. And this Similitude
+will further hold in these proprieties; that as those tinctures may be
+increased by certain bodies, so may they be precipitated by others, as I
+shall afterwards shew it to be very probable, that the like accidents
+happen even to the Air it self.
+
+Further, as these solutions and tinctures do alter the nature of these
+fluid bodies, as to their aptness to propagate a motion or impulse through
+them, even so does the particles of the Air, Water, and other fluid bodies,
+and of Glass, Crystal, &c. which are commixt with this bulk of the _AEther_
+alter the motion of the propagated pulse of light; that is, where these
+more bulkie particles are more plentifull, and consequently a lesser
+quantity of the _AEther_ between them to be mov'd, there the motion must
+necessarily be the swifter, though not so robust, which will produce those
+effects, which I have (I hope) with some probability, ascribed to it in the
+digression about Colours, at the end of the _Observations_ on
+_Muscovy-glass._
+
+Now, that other Stones, and those which have the closest and hardest
+textures, and seem (as far as we are able to discover with our eyes, though
+help'd with the best _Microscopes_) freest from pores, are yet
+notwithstanding replenish'd with them, an Instance or two will, I suppose,
+make more probable.
+
+A very solid and unflaw'd piece of cleer white _Marble_, if it be well
+polish'd and glaz'd, has so curiously smooth a surface, that the best and
+most polish'd surface of any wrought-glass, seems not to the naked eye, nor
+through a _Microscope_, to be more smooth, and less porous. And yet, that
+this hard close body is replenish'd with abundance of pores, I think these
+following Experiments will sufficiently prove.
+
+The first is, That if you take such a piece, and for a pretty while boyl it
+in Turpentine and Oyl of Turpentine, you shall find that the stone will be
+all imbu'd with it; and whereas before it look'd more white, but more
+opacous, now it will look more greasie, but be much more transparent, and
+if you let it lie but a little while, and then break off a part of it, you
+shall find the unctuous body to have penetrated it to such a determinate
+depth every way within the surface. This may be yet easier try'd with a
+piece of the same _Marble_, a little warm'd in the fire, and then a little
+Pitch or Tarr melted on the top of it; for these black bodies, by their
+insinuating themselves into the invisible pores of the stone, ting it with
+so black a hue, that there can be no further doubt of the truth of this
+assertion, that it abounds with small imperceptible pores.
+
+Now, that other bodies will also sink into the pores of _Marble_, besides
+unctuous, I have try'd, and found, that a very Blue tincture made in
+_spirit of Urine_ would very readily and easily sink into it, as would also
+several tinctures drawn with _spirit of Wine_.
+
+Nor is _Marble_ the only seemingly close stone, which by other kinds of
+Experiments may be found porous; for I have by this kind of Experiment on
+divers other stones found much the same effect, and in some, indeed much
+more notable. Other stones I have found so porous, that with the
+_Microscope_ I could perceive several small winding holes, much like
+Worm-holes, as I have noted in some kind of _Purbeck-stone_, by looking on
+the surface of a piece newly flaw'd off, for if otherwise, the surface has
+been long expos'd to the Air, or has been scraped with any tool, those
+small caverns are fill'd with dust, and disappear.
+
+And to confirm this _Conjecture_, yet further, I shall here insert an
+excellent account, given into the _Royal Society_ by that Eminently Learned
+Physician, Doctor _Goddard_, of an Experiment, not less instructive then
+curious and accurate, made by himself on a very hard and seemingly close
+stone call'd _Oculus Mundi_, as I find it preserv'd in the Records of that
+Honourable Society.
+
+    A small stone of the kind, call'd by some Authours, _Oculus Mundi_,
+    being dry and cloudy, weigh'd 5-209/256 _Grains_.
+
+    The same put under water for a night, and somewhat more, became
+    transparent, and the superficies being wiped dry, weighed 6-3/256
+    _Grains_.
+
+    The difference between these two weights, 0-50/256 of a _Grain_.
+
+    The same Stone kept out of water one Day and becoming cloudy again
+    weighed, 5-225/256 _Graines_.
+
+    Which was more then the first weight, 0-16/256 of a _Grain_.
+
+    The same being kept two Days longer weighed, 5-202/256 _Graines_.
+
+    Which was less then at first, 0-7/256 a _Grain_.
+
+    Being kept dry something longer it did not grow sensibly lighter.
+
+    Being put under water for a night and becoming again transparent and
+    wiped dry, the weight was, _6-3/256 Grains_, the same with the first
+    after putting in water, and more then the last weight after keeping of
+    it dry, 0-57/256 of a _Grain_.
+
+    Another Stone of the same kind being variegated with milky _white_ and
+    _gray_ like some sorts of _Agates_, while it lay under water, was
+    alwaies invironed with little Bubbles, such as appear in water a little
+    before boyling, next the sides of the Vessel.
+
+    There were also some the like Bubbles on the Surface of the water just
+    over it, as if either some exhalations came out of it, or that it did
+    excite some fermentation in the parts of the water contiguous to it.
+
+    There was little sensible difference in the transparency of this Stone,
+    before the putting under water, and after: To be sure the milky-_white_
+    parts continued as before, but more difference in weight then in the
+    former. For whereas before the putting into the water the weight was
+    18-97/128 _Graines_. After it had lyen in about four and twenty hours
+    the weight was 20-27/128 _Graines_, so the difference was, 1-58/128
+    _Graines_.
+
+    The same Stone was infused in the water scalding hot, and so continued
+    for a while after it was cold, but got no more weight then upon
+    infusing in the cold, neither was there any sensible Difference in the
+    weight both times.
+
+In which Experiment, there are three Observables that seem very manifestly
+to prove the porousness of these seemingly close bodies: the first is their
+acquiring a transparency, and losing their whiteness after steeping in
+water, which will seem the more strongly to argue it, if what I have
+already said about the making transparent, or clarifying of some bodies, as
+the white powder of beaten Glass, and the froth of some glutinous
+transparent liquor be well consider'd; for thereby it will seem rational to
+think that this transparency arises from the insinuation of the water
+(which has much the same refraction with such stony particles, as may be
+discover'd by Sand view'd with a _Microscope_) into those pores which were
+formerly repleat with air (that has a very differing refraction, and
+consequently is very reflective) which seems to be confirm'd by the second
+Observable, namely, the increase of weight after keeping, and decrease upon
+drying. And thirdly, seem'd yet more sensibly confirm'd by the multitude of
+bubbles in the last Experiment.
+
+We find also most Acid Salts very readily to dissolve and separate the
+parts of this body one from another; which is yet a further Argument to
+confirm the porousness of bodies, and will serve as such, to shew that even
+Glass also has an abundance of pores in it, since there are several
+liquors, that with long staying in a Glass, will so _Corrode_ and eat into
+it, as at last, to make it pervious to the liquor it contain'd, of which I
+have seen very many Instances.
+
+Since therefore we find by other proofs, that many of those bodies which we
+think the most solid ones, and appear so to our sight, have notwithstanding
+abundance of those grosser kind of pores, which will admit several kinds of
+liquors into them, why should we not believe that Glass, and all other
+transparent bodies abound with them, since we have many other arguments,
+besides the propagation of light, which seem to argue for it?
+
+And whereas it may be objected, that the propagation of light is no
+argument that there are those atomical pores in glass, since there are
+_Hypotheses_ plausible enough to solve those _Phaenomena_, by supposing the
+pulse onely to be communicated through the transparent body.
+
+To this I answer, that that _Hypothesis_ which the industrious _Mersennus_
+has publish'd about the slower motion of the end of a Ray in a denser
+_medium_, then in a more rare and thin, seems altogether unsufficient to
+solve abundance of _Phaenomena_, of which this is not the least
+considerable, that it is impossible from that supposition, that any colours
+should be generated from the refraction of the Rays; for since by that
+_Hypothesis_ the _undulating pulse_ is always carried perpendicular, or at
+right angles with the Ray or Line of direction, it follows, that the stroke
+of the pulse of light, after it has been once or twice refracted (through a
+Prisme, for example) must affect the eye with the same kind of stroke as if
+it had not been refracted at all. Nor will it be enough for a Defendant of
+that _Hypothesis_, to say, that perhaps it is because the refractions have
+made the Rays more weak, for if so, then two refractions in the two
+parallel sides of a _Quadrangular Prisme_ would produce colours, but we
+have no such _Phaenomena_ produc'd.
+
+There are several Arguments that I could bring to evince that there are in
+all transparent bodies such atomical pores. And that there is such a fluid
+body as I am arguing for, which is the _medium_, or Instrument, by which
+the pulse of Light is convey'd from the _lucid body_ to the enlightn'd. But
+that it being a digression from the Observations I was recording, about the
+Pores of _Kettering Stone_, it would be too much such, if I should protract
+it too long; and therefore I shall proceed to the next _Observation_.
+
+       *       *       *       *       *
+
+
+Observ. XVI. _Of _Charcoal_, or burnt _Vegetables_._
+
+Charcoal, or a Vegetable burnt black, affords an object no less pleasant
+than instructive, for if you take a small round Charcoal, and break it
+short with your fingers, you may perceive it to break with a very smooth
+and sleek surface, almost like the surface of black sealing Wax; this
+surface, if it be look'd on with an ordinary _Microscope_, does manifest
+abundance of those pores which are also visible to the eye in many kinds of
+_Wood_, rang'd round the pith, both a in kind of circular order, and a
+radiant one. Of these there are a multitude in the substance of the Coal,
+every where almost perforating and drilling it from end to end; by means of
+which, be the Coal never so long, you may easily blow through it; and this
+you may presently find, by wetting one end of it with Spittle, and blowing
+at the other.
+
+But this is not all, for besides those many great and conspicuous irregular
+spots or pores, if a better _Microscope_ be made use of, there will appear
+an infinite company of exceedingly small, and very regular pores, so thick
+and so orderly set, and so close to one another, that they leave very
+little room or space between them to be fill'd with a solid body, for the
+apparent _interstitia_ or separating sides of these pores seem so thin in
+some places, that the texture of a Honey-comb cannot be more porous. Though
+this be not every where so, the intercurrent partitions in some places
+being very much thicker in proportion to the holes.
+
+Most of these small pores seem'd to be pretty round, and were rang'd in
+rows that radiated from the pith to the bark; they all of them seem'd to be
+continued open pores, running the whole length of the Stick; and that they
+were all perforated, I try'd by breaking off a very thin sliver of the Coal
+cross-ways, and then with my _Microscope_, diligently surveying them
+against the light, for by that means I was able to see quite through them.
+
+These pores were so exceeding small and thick, that in a line of them, 1/18
+part of an Inch long, I found by numbring them no less then 150. small
+pores; and therefore in a line of them an Inch long, must be no less then
+2700. pores, and in a circular _area_ of an Inch diameter, must be about
+5725350. of the like pores; so that a Stick of an Inch Diameter, may
+containe no less then seven hundred and twenty five thousand, besides 5
+Millions of pores, which would, I doubt not, seem even incredible, were not
+every one left to believe his own eyes. Nay, having since examin'd _Cocus,
+black and green Ebony, Lignum Vitae_, &c. I found, that all these Woods
+have their pores, abundantly smaller then those of soft light Wood; in so
+much, that those of _Guajacum_ seem'd not above an eighth part of the
+bigness of the pores of Beech, but then the _Interstitia_ were thicker; so
+prodigiously curious are the contrivances, pipes, or sluces by which the
+_Succus nutritius_, or Juyce of a Vegetable is convey'd from place to
+place.
+
+This _Observation_ seems to afford us the true reason of several
+_Phaenomena_ of Coals; as
+
+First, why they look black; and for this we need go no further then the
+_Scheme_, for certainly, a body that has so many pores in it as this is
+discover'd to have, from each of which no light is reflected, must
+necessarily look black, especially, when the pores are somewhat bigger in
+proportion to the intervals then they are cut in the _Scheme_, black being
+nothing else but a privation of Light, or a want of reflection; and
+wheresover this reflecting quality is deficient, there does that part look
+black, whether it be from a porousness of the body, as in this Instance, or
+in a deadning and dulling quality, such as I have observ'd in the _Scoria_
+of Lead, Tin, Silver, Copper, &c.
+
+Next, we may also as plainly see the reason of its shining quality, and
+that is from the even breaking off of the stick, the solid _interstitia_
+having a regular termination or surface, and having a pretty strong
+reflecting quality, the many small reflections become united to the naked
+eye, and make a very pretty shining surface.
+
+Thirdly, the reason of its hardness and brittleness seems evident, for
+since all the watery or liquid substance that moistn'd and toughn'd those
+_Interstitia_ of the more solid parts, are evaporated and remov'd, that
+which is left behind becomes of the nature almost of a stone, which will
+not at all, or very little, bend without a _divulsion_ or _solution_ of its
+_continuity_.
+
+It is not my design at present, to examine the use and _Mechanisme_ of
+these parts of Wood, that being more proper to another Enquiry; but rather
+to hint, that from this Experiment we may learn,
+
+First, what is the cause of the blackness of many burnt bodies, which we
+may find to be nothing else but this; that the heat of the fire agitating
+and rarifying the waterish, transparent, and volatile water that is
+contain'd in them, by the continuation of that action, does so totally
+expel and drive away all that which before fill'd the pores, and was
+dispers'd also through the solid mass of it, and thereby caus'd an
+universal kind of transparency, that it not onely leaves all the pores
+empty, but all the _Interstitia_ also so dry and _opacous_, and perhaps
+also yet further perforated, that that light onely is reflected back which
+falls upon the very outward edges of the pores, all they that enter into
+the pores of the body, never returning, but being lost in it.
+
+Now, that the Charring or coaling of a body is nothing else, may be easily
+believ'd by one that shall consider the means of its production, which may
+be done after this, or any such manner. The body to be charr'd or coal'd,
+may be put into a _Crucible_, Pot, or any other Vessel that will endure to
+be made red-hot in the fire without breaking, and then cover'd over with
+Sand, so as no part of it be suffer'd to be open to the Air, then set into
+a good fire, and there kept till the Sand has continu'd red hot for a
+quarter, half, an hour or two, or more, according to the nature and bigness
+of the body to be coal'd or charr'd, then taking it out of the fire, and
+letting it stand till it be quite cold, the body may be taken out of the
+Sand well charr'd and cleans'd of its waterish parts; but in the taking of
+it out, care must be had that the Sand be very neer cold, for else, when it
+comes into the free air, it will take fire, and readily burn away.
+
+This maybe done also in any close Vessel of Glass, as a _Retort_, or the
+like, and the several fluid substances that come over may be receiv'd in a
+fit _Recipient_, which will yet further countenance this _Hypothesis_: And
+their manner of charring Wood in great quantity comes much to the same
+thing, namely, an application of a great heat to the body, and preserving
+it from the free access of the devouring air; this may be easily learn'd
+from the History of Charring of Coal, most excellently describ'd and
+publish'd by that most accomplish'd Gentleman, Mr. _John Evelin_, in the
+100, 101, 103, pages of his _Sylva_, to which I shall therefore refer the
+curious Reader that desires a full information of it.
+
+Next, we may learn what part of the Wood it is that is the _combustible_
+matter, for since we shall find that none, or very little of those fluid
+substances that are driven over into the Receiver are _combustible_, and
+that most of that which is left behind is so, it follows, that the solid
+_interstitia_ of the Wood are the _combustible_ matter. Further, the reason
+why uncharr'd Wood burns with a greater flame then that which is charr'd,
+is as evident, because those waterish or volatil parts issuing out of the
+fired Wood, every way, not onely shatter and open the body, the better for
+the fire to enter, but issuing out in vapours or wind, they become like so
+many little _aeolipiles_, or Bellows, whereby they blow and agitate the
+fir'd part, and conduce to the more speedy and violent consumption or
+dissolution of the body.
+
+Thirdly, from the Experiment of charring of Coals (whereby we see that
+notwithstanding the great heat, and the duration of it, the solid parts of
+the Wood remain, whilest they are preserv'd from the free access of the air
+undissipated) we may learn, that which has not, that I know of, been
+publish'd or hinted, nay, not so much as thought of, by any; and that in
+short is this.
+
+First, _that the Air_ in which we live, move, and breath, and which
+encompasses very many, and cherishes most bodies it encompasses, that this
+Air is the _menstruum_, or universal dissolvent of all _Sulphureous_
+bodies.
+
+Secondly, _that this action_ it performs not, till the body be first
+sufficiently heated, as we find requisite also to the dissolution of many
+other bodies by several other _menstruums_.
+
+Thirdly, _that this action_ of dissolution, produces or generates a very
+great heat, and that which we call Fire; and this is common also to many
+dissolutions of other bodies, made by _menstruums_, of which I could give
+multitudes of Instances.
+
+Fourthly, _that this action_ is perform'd with so great a violence, and
+does so minutely act, and rapidly agitate the smallest parts of the
+_combustible_ matter, that it produces in the _diaphanous medium_ of the
+Air, the action or pulse of light, which what it is, I have else-where
+already shewn.
+
+Fifthly, _that the dissolution_ of sulphureous bodies is made by a
+substance inherent, and mixt with the Air, that is like, if not the very
+same, with that which is fixt in _Salt-peter_, which by multitudes of
+Experiments that may be made with _Saltpeter_, will, I think, most
+evidently be demonstrated.
+
+Sixthly, _that in this dissolution_ of bodies by the Air, a certain part is
+united and mixt, or dissolv'd and turn'd into the Air, and made to fly up
+and down with it in the same manner as a _metalline_ or other body
+dissolved into any _menstruums_, does follow the motions and progresses of
+that _menstruum_ till it be precipitated.
+
+Seventhly, That as there is one part that is dissoluble by the Air, so are
+there other parts with which the parts of the Air mixing and uniting, do
+make a _Coagulum_, or _precipitation_, as one may call it, which causes it
+to be separated from the Air, but this _precipitate_ is so light, and in so
+small and rarify'd or porous clusters, that it is very volatil, and is
+easily carry'd up by the motion of the Air, though afterwards, when the
+heat and agitation that kept it rarify'd ceases, it easily condenses, and
+commixt with other indissoluble parts, it sticks and adheres to the next
+bodies it meets withall; and this is a certain _Salt_ that may be extracted
+out of _Soot_.
+
+Eighthly, that many indissoluble parts being very apt and prompt to be
+rarify'd, and so, whilest they continue in that heat and agitation, are
+lighter then the Ambient Air, are thereby thrust and carry'd upwards with
+great violence, and by that means carry along with them, not onely that
+_Saline concrete_ I mention'd before, but many terrestrial, or indissoluble
+and irrarefiable parts, nay, many parts also which are dissoluble, but are
+not suffer'd to stay long enough in a sufficient heat to make them prompt
+and apt for that action. And therefore we find in _Soot_, not onely a part,
+that being continued longer in a competent heat, will be dissolv'd by the
+Air, or take fire and burn; but a part also which is fixt, terrestrial, and
+irrarefiable.
+
+Ninthly, that as there are these several parts that will rarifie and fly,
+or be driven up by the heat, so are there many others, that as they are
+indissoluble by the _aerial menstruum_, so are they of such sluggish and
+gross parts, that they are not easily rarify'd by heat, and therefore
+cannot be rais'd by it; the volatility or fixtness of a body seeming to
+consist only in this, that the one is of a texture, or has component parts
+that will be easily rarify'd into the form of Air, and the other, that it
+has such as will not, without much ado, be brought to such a constitution;
+and this is that part which remains behind in a white body call'd Ashes,
+which contains a substance, or _Salt_, which Chymists call _Alkali_: what
+the particular natures of each of these bodies are, I shall not here
+examine, intending it in another place, but shall rather add that this
+_Hypothesis_ does so exactly agree with all _Phaenomena_, of Fire, and so
+genuinely explicate each particular circumstance that I have hitherto
+observ'd, that it is more then probable, that this cause which I have
+assign'd is the true adequate, real, and onely cause of those _Phaenomena_;
+And therefore I shall proceed a little further, to shew the nature and use
+of the Air.
+
+Tenthly, therefore the dissolving parts of the Air are but few, that is, it
+seems of the nature of those _Saline menstruums_, or spirits, that have
+very much flegme mixt with the spirits, and therefore a small parcel of it
+is quickly glutted, and will dissolve no more; and therefore unless some
+fresh part of this _menstruum_ be apply'd to the body to be dissolv'd, the
+action ceases, and the body leaves to be dissolv'd and to shine, which is
+the Indication of it, though plac'd or kept in the greatest heat; whereas
+_Salt-peter_ is a _menstruum_, when melted and red-hot, that abounds more
+with those Dissolvent particles, and therefore as a small quantity of it
+will dissolve a great sulphureous body, so will the dissolution be very
+quick and violent.
+
+Therefore in the _Eleventh_ place, it is observable, that, as in other
+solutions, if a copious and quick supply of fresh _menstruum_, though but
+weak, be poured on, or applied to the dissoluble body, it quickly consumes
+it: So this _menstruum_ of the Air, if by Bellows, or any other such
+contrivance, it be copiously apply'd to the shining body, is found to
+dissolve it as soon, and as violently as the more strong _menstruum_ of
+melted _Nitre_.
+
+Therefore twelfthly, it seems reasonable to think that there is no such
+thing as an Element of Fire that should attract or draw up the flame, or
+towards which the flame should endeavour to ascend out of a desire or
+appetite of uniting with that as its _Homogeneal_ primitive and generating
+Element; but that that shining transient body which we call _Flame_, is
+nothing else but a mixture of Air, and volatil sulphureous parts of
+dissoluble or combustible bodies, which are acting upon each other whilst
+they ascend, that is, flame seems to be a mixture of Air, and the
+combustible volatil parts of any body, which parts the encompassing Air
+does dissolve or work upon, which action, as it does intend the heat of the
+_aerial_ parts of the dissolvent, so does it thereby further rarifie those
+parts that are acting, or that are very neer them, whereby they growing
+much lighter then the heavie parts of that _menstruum_ that are more
+remote, are thereby protruded and driven upward; and this may be easily
+observ'd also in dissolution made by any other _menstruum_, especially such
+as either create heat or bubbles. Now, this action of the _menstruum_, or
+_Air_, on the dissoluble parts, is made with such violence, or is such,
+that it imparts such a motion or pulse to the _diaphanous_ parts of the
+Air, as I have elsewhere shewn is requisite to produce light.
+
+This _Hypothesis_ I have endeavoured to raise from an Infinite of
+Observations and Experiments, the process of which would be much too long
+to be here inserted, and will perhaps another time afford matter copious
+enough for a much larger Discourse, the Air being a Subject which (though
+all the world has hitherto liv'd and breath'd in, and been unconversant
+about) has yet been so little truly examin'd or explain'd, that a diligent
+enquirer will be able to find but very little information from what has
+been (till of late) written of it: But being once well understood, it will,
+I doubt not, inable a man to render an intelligible, nay probable, if not
+the true reason of all the _Phaenomena_ of Fire, which, as it has been
+found by Writers and Philosophers of all Ages a matter of no small
+difficulty, as may be sufficiently understood by their strange
+_Hypotheses_, and unintelligible Solutions of some few _Phaenomena_ of it;
+so will it prove a matter of no small concern and use in humane affairs, as
+I shall elsewhere endeavour to manifest when I come to shew the use of the
+Air in respiration, and for the preservation of the life, nay, for the
+conservation and restauration of the health and natural constitution of
+mankind as well as all other aereal _animals_, as also the uses of this
+principle or propriety of the Air in chymical, mechanical, and other
+operations. In this place I have onely time to hint an _Hypothesis_, which,
+if God permit me life and opportunity, I may elsewhere prosecute, improve
+and publish. In the mean time, before I finish this Discourse, I must not
+forget to acquaint the Reader, that having had the liberty granted me of
+making some trials on a piece of _Lignum fossile_ shewn to the Royal
+Society, by the eminently Ingenious and Learned Physician, Doctor _Ent_,
+who receiv'd it for a Present from the famous _Ingenioso Cavalliero de
+Pozzi_, it being one of the fairest and best pieces of _Lignum fossile_ he
+had seen; Having (I say) taken a small piece of this Wood, and examin'd it,
+I found it to burn in the open Air almost like other Wood, and insteed of a
+resinous smoak or fume, it yielded a very bituminous one, smelling much of
+that kind of sent: But that which I chiefly took notice of, was, that
+cutting off a small piece of it, about the bigness of my Thumb, and
+charring it in a _Crucible_ with Sand, after the manner I above prescrib'd,
+I found it infinitely to abound with the smaller sort of pores, so
+extreamly thick, and so regularly perforating the substance of it
+long-ways, that breaking it off a-cross, I found it to look very like an
+Honey-comb; but as for any of the second, or bigger kind of pores, I could
+not find that it had any; so that it seems, whatever were the cause of its
+production, it was not without those small kind of pores which we have
+onely hitherto found in Vegetable bodies: and comparing them with the pores
+which I have found in the Charcoals that I by this means made of several
+other kinds of Wood, I find it resemble none so much as those of Fire, to
+which it is not much unlike in grain also, and several other proprieties.
+
+And therefore, what ever is by some, who have written of it, and
+particularly by _Francisco Stelluto_, wrote a Treatise in _Italian_ of that
+Subject, which was Printed at _Rome_, 1637, affirm'd that it is a certain
+kind of Clay or Earth, which in tract of time is turn'd into Wood; I rather
+suspect the quite contrary, that it was at first certain great Trees of Fir
+or Pine, which by some Earthquake, or other casualty, came to be buried
+under the Earth, and was there, after a long time's residence (according to
+the several natures of the encompassing adjacent parts) either rotted and
+turn'd into a kind of Clay, or _petrify'd_ and turn'd into a kind of Stone,
+or else had its pores fill'd with certain Mineral juices, which being
+stay'd in them, and in tract of time coagulated, appear'd, upon cleaving
+out, like small Metaline Wires, or else from some flames or scorching forms
+that are the occasion oftentimes, and usually accompany Earthquakes, might
+be blasted and turn'd into Coal, or else from certain _subterraneous_ fires
+which are affirm'd by that Authour to abound much about those parts
+(namely, in a Province of _Italy_, call'd _Umbria_, now the _Dutchie_ of
+_Spoletto_, in the Territory of _Todi_, anciently call'd _Tudor_; and
+between the two Villages of _Collesecco_ and _Rosaro_ not far distant from
+the high-way leading to _Rome_, where it is found in greater quantity then
+elsewhere) are by reason of their being encompassed with Earth, and so kept
+close from the dissolving Air, charr'd and converted into Coal. It would be
+too long a work to describe the several kinds of pores which I met withall,
+and by this means discovered in several other Vegetable bodies; nor is it
+my present design to expatiate upon Instances of the same kind, but rather
+to give a Specimen of as many kinds as I have had opportunity as yet of
+observing, reserving the prosecution and enlarging on particulars till a
+more fit opportunity; and in prosecution of this design, I shall here add:
+
+       *       *       *       *       *
+
+
+Observ. XVII. _Of _Petrify'd wood_, and other _Petrify'd bodies_._
+
+Of this sort of substance, I observ'd several pieces of very differing
+kinds, both for their outward shape, colour, grain, _texture_, hardness,
+&c. some being brown and redish; others gray, like a Hone; others black,
+and Flint-like: some soft, like a Slate or Whetstone, others as hard as a
+Flint, and as brittle. That which I more particular examin'd, was a piece
+about the bigness of a mans hand, which seem'd to have been a part of some
+large tree, that by rottenness had been broken off from it before it began
+to be _petrify'd_.
+
+And indeed, all that I have yet seen, seem to have been rotten Wood before
+the petrifaction was begun; and not long since, examining and viewing a
+huge great _Oak_, that seem'd with meer age to be rotten as it stood, I was
+very much confirm'd in this opinion; for I found, that the grain, colour,
+and shape of the Wood, was exactly like this _petrify'd_ substance; and
+with a _Microscope_, I found, that all those _Microscopical_ pores, which
+in sappy or firm and sound Wood are fill'd with the natural or innate
+juices of those Vegetables, in this they were all empty, like those of
+_Vegetables charr'd_; but with this difference, that they seem'd much
+larger then I have seen any in _Char-coals_; nay, even then those of Coals
+made of great blocks of Timber, which are commonly call'd _Old-coals_.
+
+The reason of which difference may probably be, that the charring of
+Vegetables, being an operation quickly perform'd, and whilest the Wood is
+sappy, the more solid parts may more easily shrink together, and contract
+the pores or _interstitia_ between them, then in the rotten Wood, where
+that natural juice seems onely to be wash'd away by _adventitious_ or
+unnatural moisture; and so though the natural juice be wasted from between
+the firm parts, yet those parts are kept asunder by the _adventitious_
+moystures, and so by degrees settled in those postures.
+
+And this I likewise found in the _petrify'd_ Wood, that the pores were
+somewat bigger then those of _Charcoal_, each pore being neer upon half as
+bigg again, but they did not bear that disproportion which is exprest in
+the tenth _Scheme_, between the small specks or pores in the first Figure
+(which representeth the pores of Coal or Wood charr'd) and the black spots
+of the second Figure (which represent the like _Microscopical pores_ in the
+_petrify'd_ Wood) for these last were drawn by a _Microscope_ that
+magnify'd the object above six times more in Diameter then the _Microscope_
+by which those pores of Coal were observ'd.
+
+Now, though they were a little bigger, yet did they keep the exact figure
+and order of the pores of Coals and of rotten Wood, which last also were
+much of the same cize.
+
+The other Observations on this _petrify'd_ substance, that a while since,
+by the appointment of the _Royal Society_, I made, and presented to them an
+account of, were these that follow, which had the honour done them by the
+most accomplish'd Mr. _Evelin_, my highly honoured friend, to be inserted
+and published among those excellent Observations wherewith his _Sylva_ is
+replenish'd, and would therefore have been here omitted, had not the Figure
+of them, as they appear'd through the _Microscope_ been before that
+engraven.
+
+This _Petrify'd_ substance resembled Wood, in that
+
+First, all the parts of it seem'd not at all _dislocated_, or alter'd from
+their natural Position, whil'st they were Wood, but the whole piece
+retain'd the exact shape of Wood, having many of the conspicuous pores of
+wood still remaining pores, and shewing a manifest difference visible
+enough between the grain of the Wood and that of the bark, especially when
+any side of it was cut smooth and polite; for then it appear'd to have a
+very lovely grain, like that of some curious close Wood.
+
+Next (it resembled Wood) in that all the smaller and (if I may so call
+those which are onely visible with a good magnifying Glass) _Microscopical_
+pores of it appear (both when the substance is cut and polish'd
+_transversly_ and _parallel_ to the pores of it) perfectly like the
+_Microscopical_ pores of several kinds of Wood, especially like and equal
+to those of several sorts of rotten Wood which I have since observ'd,
+retaining both the shape, position and magnitude of such pores. It was
+differing from Wood:
+
+First; in _weight_, being to common water as 31/4 to 1. whereas there are
+few of our _English_ Woods, that when very dry are found to be full as
+heavie as water.
+
+Secondly, in _hardness_, being very neer as hard as a Flint; and in some
+places of it also resembling the grain of a Flint: and, like it, it would
+very readily cut Glass, and would not without difficulty, especially in
+some parts of it, be scratch'd by a black hard Flint: It would also as
+readily strike fire against a Steel, or against a Flint, as any common
+Flint.
+
+Thirdly, in the _closeness_ of it, for though all the _Microscopical_ pores
+of this _petrify'd_ substance were very conspicuous in one position, yet by
+altering that position of the polish'd surface to the light, it was also
+manifest, that those pores appear'd darker then the rest of the body, onely
+because they were fill'd up with a more duskie substance, and not because
+they were hollow.
+
+Fourthly, in its _incombustibleness_, in that it would not burn in the
+fire; nay, though I kept it a good while red-hot in the flame of a Lamp,
+made very _intense_ by the blast of a small Pipe, and a large Charcoal, yet
+it seem'd not at all to have diminish'd its extension; but only I found it
+to have chang'd its colour, and to appear of a more dark and duskie brown
+colour; nor could I perceive that those parts which seem'd to have been
+Wood at first, were any thing wasted, but the parts appear'd as solid and
+close as before. It was further observable also, that as it did not consume
+like Wood, so neither did it crack and flie like a Flint, or such like hard
+Stone, nor was it long before it appear'd red-hot.
+
+Fifthly, in its _dissolubleness_; for putting some drops of distill'd
+_Vinegar_ upon the Stone, I found it presently to yield very many Bubbles,
+just like those which may be observ'd in spirit of _Vinegar_ when it
+corrodes _corals_, though perhaps many of those small Bubbles might proceed
+from some small parcels of Air which were driven out of the pores of this
+_petrify'd_ substance by the insinuating liquid _menstruum_.
+
+Sixthly, in its _rigidness_, and _friability_, being not at all flexible
+but brittle like a Flint, insomuch that I could with one knock of a Hammer
+break off a piece of it, and with a few more, reduce that into a pretty
+fine powder.
+
+Seventhly, it seem'd also very differing from Wood to the _touch_,
+_feeling_ more cold then Wood usually does, and much like other close
+stones and Minerals.
+
+The Reasons of all which _Phaenomena_ seem to be,
+
+That _petrify'd_ Wood having lain in some place where it was well soak'd
+with _petrifying_ water (that is, such a water as is well _impregnated_
+with stony and earthy particles) did by degrees separate, either by
+straining and _filtration_, or perhaps, by _precipitation_, _cohesion_ or
+_coagulation_, abundance of stony particles from the permeating water,
+which stony particles, being by means of the fluid _vehicle_ convey'd, not
+onely into the _Microscopical_ pores, and so perfectly stoping them up, but
+also into the pores or _interstitia_, which may, perhaps, be even in the
+texture or _Schematisme_ of that part of the Wood, which, through the
+_Microscope_, appears most solid, do thereby so augment the weight of the
+Wood, as to make it above three times heavier then water, and perhaps, six
+times as heavie as it was when Wood.
+
+Next, they thereby so lock up and fetter the parts of the Wood, that the
+fire cannot easily make them flie away, but the action of the fire upon
+them is onely able to _Char_ those parts, as it were, like a piece of Wood,
+if it be clos'd very fast up in Clay, and kept a good while red-hot in the
+fire, will by the heat of the fire be charr'd and not consum'd, which may,
+perhaps, also be somewhat of the cause, why the _petrify'd_ substance
+appear'd of a dark brown colour after it had been burnt.
+
+By this _intrusion_ of the _petrifying_ particles, this substance also
+becomes hard and _friable_; for the smaller pores of the Wood being
+perfectly wedg'd, and stuft up with those stony particles, the small parts
+of the Wood have no places or pores into which they may slide upon bending,
+and consequently little or no flexion or yielding at all can be caus'd in
+such a substance.
+
+The remaining particles likewise of the Wood among the stony particles, may
+keep them from cracking and flying when put into the fire, as they are very
+apt to do in a Flint.
+
+Nor is Wood the onely substance that may by this kind of _transmutation_ be
+chang'd into stone; for I my self have seen and examin'd very many kinds of
+substances, and among very credible Authours, we may meet with Histories of
+such _Metamorphoses_ wrought almost on all kind of substances, both
+_Vegetable_ and _Animal_, which Histories, it is not my business at
+present, either to relate, or _epitomise_, but only to set down some
+Observation I lately made on several kind of _petrify'd_ Shels, found about
+_Keinsham_, which lies within four or five miles of _Bristol_, which are
+commonly call'd _Serpentine-stones._
+
+Examining several of these very curiously figur'd bodies (which are
+commonly thought to be Stones form'd by some extraordinary _Plastick
+virtue_ _latent_ in the Earth itself) I took notice of these particulars:
+
+First, that these figured bodies, or stones, were of very differing
+substances, as to hardness: some of Clay, some Marle, some soft Stone,
+almost of the hardness of those soft stones which Masons call Fire-stone,
+others as hard as Portland stone, others as hard as Marble, and some as
+hard as a Flint or Crystal.
+
+Next, they were of very differing substances as to transparency and colour;
+some white, some almost black, some brown, some Metalline, or like
+Marchasites; some transparent like white Marble, others like flaw'd
+Crystal, some gray, some of divers colours; some radiated like those long
+_petrify'd drops_, which are commonly found at the _Peak_, and in other
+_subterraneous caverns_, which have a kind of pith in the middle.
+
+Thirdly, that they were very different as to the manner of their outward
+figuration; for some of them seem'd to have been the substance that had
+fill'd the Shell of some kind of Shel-fish; others, to have been the
+substance that had contain'd or enwrapp'd one of those Shels, on both
+which, the perfect impression either of the inside or outside of such
+Shells seem'd to be left, but for the most part, those impressions seem'd
+to be made by an imperfect or broken Shell, the great end or mouth of the
+Shell being always wanting, and often times the little end, and sometimes
+half, and in some there were impressions, just as if there had been holes
+broken in the figurating, imprinting or moulding Shell; some of them seem'd
+to be made by such a Shell very much brused or flaw'd, insomuch that one
+would verily have thought that very figur'd stone had been broken or brused
+whilst a gelly, as 'twere, and so hardned, but within in the grain of the
+stone, there appear'd not the least sign of any such bruse or breaking, but
+onely on the very uttermost superficies.
+
+Fourthly, they were very different, as to their outward covering, some
+having the perfect Shell, both in figure, colour, and substance, sticking
+on upon its surface, and adhering to it, but might very easily be separated
+from it, and like other common _Cockle_ or _Scolop-shels_, which some of
+them most accurately resembled, were very dissoluble in common _Vinegar_,
+others of them, especially those _Serpentine_, or _Helical stones_ were
+cover'd or retained the shining or Pearl-colour'd substance of the inside
+of a Shel, which substance, on some parts of them, was exceeding thin, and
+might very easily be rubbed off; on other parts it was pretty thick, and
+retained a white coat, or flaky substance on the top, just like the
+outsides of such Shells; some of them had very large pieces of the Shell
+very plainly sticking on to them, which were easily to be broken or flaked
+off by degrees: they likewise, some of them retain'd all along the surface
+of them very pretty kind of _sutures_, such as are observ'd in the skulls
+of several kinds of living creatures, which _sutures_ were most curiously
+shap'd in the manner of leaves, and every one of them in the same Shell,
+exactly one like another, which I was able to discover plainly enough with
+my naked eye, but more perfectly and distinctly with my _Microscope_; all
+these sutures, by breaking some of these stones, I found to be the
+_termini_, or boundings of certain _diaphragms_, or partitions, which
+seem'd to divide the cavity of the Shell into a multitude of very
+proportionate and regular _cells_ or _caverns_, these _Diaphragms_, in many
+of them, I found very perfect and compleat, of a very distinct substance
+from that which fill'd the cavities, and exactly of the same kind with that
+which covered the outside, being for the most part whitish, or
+_mother-of-pearl_ colour'd.
+
+As for the cavities between those _Diaphragms_, I found some of them fill'd
+with Marle, and others with several kinds of stones, others, for the most
+part hollow, onely the whole cavity was usually covered over with a kind of
+_tartareous petrify'd_ substance, which stuck about the sides, and was
+there shot into very curious regular Figures, just as _Tartar_, or other
+dissolv'd Salts are observ'd to stick and _crystallize_ about the sides of
+the containing Vessels; or like those little _Diamants_ which I before
+observed to have covered the vaulted cavity of a Flint; others had these
+cavities all lin'd with a kind of _metalline_ or _marchasite-like_
+substance, which with a _Microscope_ I could as plainly see most curiously
+and regularly figured, as I had done those in a Flint.
+
+From all which, and several other particulars which I observ'd, I cannot
+but think, that all these, and most other kinds of stony bodies which are
+found thus strangely figured, do owe their formation and figuration, not to
+any kind of _Plastick virtue_ inherent in the earth, but to the Shells of
+certain Shel-fishes, which, either by some Deluge, Inundation, Earthquake,
+or some such other means, came to be thrown to that place, and there to be
+fill'd with some kind of Mudd or Clay, or _petrifying_ Water, or some other
+substance, which in tract of time has been settled together and hardned in
+those shelly moulds into those shaped substances we now find them; that the
+great and thin end of these Shells by that Earthquake, or what ever other
+extraordinary cause it was that brought them thither, was broken off; and
+that many others were otherwise broken, bruised and disfigured; that these
+Shells which are thus _spirallied_ and separated with _Diaphragmes_, were
+some kind of _Nautili_ or _Porcelane shells_; and that others were shells
+of _Cockles_, _Muscles_, _Periwincles_, _Scolops_, &c. of various sorts;
+that these Shells in many, from the particular nature of the containing or
+enclos'd Earth, or some other cause, have in tract of time rotted and
+mouldred away, and onely left their impressions, both on the containing and
+contained substances; and so left them pretty loose one within another, so
+that they may be easily separated by a knock or two of a Hammer. That
+others of these Shells, according to the nature of the substances adjacent
+to them, have, by a long continuance in that posture, been _petrify'd_ and
+turn'd into the nature of stone, just as I even now observ'd several sorts
+of Wood to be. That oftentimes the Shell may be found with one kind of
+substance within, and quite another without; having, perhaps, been fill'd
+in one place, and afterwards translated to another, which I have very
+frequently observ'd in _Cockle_, _Muscle_, _Periwincle_, and other shells,
+which I have found by the Sea side. Nay, further, that some parts of the
+same Shell may be fill'd in one place, and some other caverns in another,
+and others in a third, or a fourth, or a fifth place, for so many differing
+substances have I found in one of these _petrify'd_ Shells, and perhaps all
+these differing from the encompassing earth or stone; the means how all
+which varieties may be caus'd, I think, will not be difficult to conceive,
+to any one that has taken notice of those Shells, which are commonly found
+on the Sea shore: And he that shall throughly examine several kinds of such
+curiously form'd stones, will (I am very apt to think) find reason to
+suppose their generation or formation to be ascribable to some such
+accidents as I have mention'd, and not to any _Plastick virtue_: For it
+seems to me quite contrary to the infinite prudence of Nature, which is
+observable in all its works and productions, to design every thing to a
+determinate end, and for the attaining of that end, makes use of such ways
+as are (as farr as the knowledge of man has yet been able to reach)
+altogether consonant, and most agreeable to man's reason, and of no way or
+means that does contradict, or is contrary to humane Ratiocination; whence
+it has a long time been a general observation and _maxime_, that _Nature
+does nothing in vain_; It seems, I say, contrary to that great Wisdom of
+Nature, that these prettily shap'd bodies should have all those curious
+Figures and contrivances (which many of them are adorn'd and contriv'd
+with) generated or wrought by a _Plastick virtue_, for no higher end, then
+onely to exhibite such a form; which he that shall throughly consider all
+the circumstances of such kind of Figur'd bodies, will, I think, have great
+reason to believe, though, I confess, one cannot presently be able to find
+out what Nature's designs are. It were therefore very desirable, that a
+good collection of such kind of figur'd stones were collected; and as many
+particulars, circumstances, and informations collected with them as could
+be obtained, that from such a History of Observations well rang'd, examin'd
+and digested, the true original or production of all those kinds of stones
+might be perfectly and surely known; such as are _Thunder-stones_, _Lapides
+Stellares_, _Lapides Judaici_, and multitudes of other, whereof mention is
+made in _Aldonandus_, _Wormius_, and other Writers of Minerals.
+
+       *       *       *       *       *
+
+
+Observ. XVIII. _Of the _Schematisme_ or _Texture_ of _Cork_, and of the
+Cells and Pores of some other such frothy Bodies._
+
+I took a good clear piece of Cork, and with a Pen-knife sharpen'd as keen
+as a Razor, I cut a piece of it off, and thereby left the surface of it
+exceeding smooth, then examining it very diligently with a _Microscope_, me
+thought I could perceive it to appear a little porous; but I could not so
+plainly distinguish them, as to be sure that they were pores, much less
+what Figure they were of: But judging from the lightness and yielding
+quality of the Cork, that certainly the texture could not be so curious,
+but that possibly, if I could use some further diligence, I might find it
+to be discernable with a _Microscope_, I with the same sharp Penknife, cut
+off from the former smooth surface an exceeding thin piece of it, and
+placing it on a black object Plate, because it was it self a white body,
+and casting the light on it with a deep _plano-convex Glass_, I could
+exceeding plainly perceive it to be all perforated and porous, much like a
+Honey-comb, but that the pores of it were not regular; yet it was not
+unlike a Honey-comb in these particulars.
+
+First, in that it had a very little solid substance, in comparison of the
+empty cavity that was contain'd between, as does more manifestly appear by
+the Figure A and B of the XI. _Scheme_, for the _Interstitia_, or walls (as
+I may so call them) or partitions of those pores were neer as thin in
+proportion to their pores, as those thin films of Wax in a Honey-comb
+(which enclose and constitute the _sexangular celts_) are to theirs.
+
+Next, in that these pores, or cells, were not very deep, but consisted of a
+great many little Boxes, separated out of one continued long pore, by
+certain _Diaphragms_, as is visible by the Figure B, which represents a
+sight of those pores split the long-ways.
+
+I no sooner discern'd these (which were indeed the first _microscopical_
+pores I ever saw, and perhaps, that were ever seen, for I had not met with
+any Writer or Person, that had made any mention of them before this) but me
+thought I had with the discovery of them, presently hinted to me the true
+and intelligible reason of all the _Phaenomena_ of Cork; As,
+
+First, if I enquir'd why it was so exceeding light a body? my _Microscope_
+could presently inform me that here was the same reason evident that there
+is found for the lightness of froth, an empty Honey-comb, Wool, a Spunge, a
+Pumice-stone, or the like; namely, a very small quantity of a solid body,
+extended into exceeding large dimensions.
+
+Next, it seem'd nothing more difficult to give an intelligible reason, why
+Cork is a body so very unapt to suck and drink in Water, and consequently
+preserves it self, floating on the top of Water, though left on it never so
+long: and why it is able to stop and hold air in a Bottle, though it be
+there very much condens'd and consequently presses very strongly to get a
+passage out, without suffering the least bubble to pass through its
+substance. For, as to the first, since our _Microscope_ informs us that the
+substance of Cork is altogether fill'd with Air, and that that Air is
+perfectly enclosed in little Boxes or Cells distinct from one another. It
+seems very plain, why neither the Water, nor any other Air can easily
+insinuate it self into them, since there is already within them an _intus
+existens_, and consequently, why the pieces of Cork become so good floats
+for Nets, and stopples for Viols, or other close Vessels.
+
+And thirdly, if we enquire why Cork has such a springiness and swelling
+nature when compress'd? and how it comes to suffer so great a compression,
+or seeming penetration of dimensions, so as to be made a substance as
+heavie again and more, bulk for bulk, as it was before compression, and yet
+suffer'd to return, is found to extend it self again into the same space?
+Our _Microscope_ will easily inform us, that the whole mass consists of an
+infinite company of small Boxes or Bladders of Air, which is a substance of
+a springy nature, and that will suffer a considerable condensation (as I
+have several times found by divers trials, by which I have most evidently
+condens'd it into less then a twentieth part of its usual dimensions neer
+the Earth, and that with no other strength then that of my hands without
+any kind of forcing Engine, such as Racks, Leavers, Wheels, Pullies, or the
+like, but this onely by and by) and besides, it seems very probable that
+those very films or sides of the pores, have in them a springing quality,
+as almost all other kind of Vegetable substances have, so as to help to
+restore themselves to their former position.
+
+And could we so easily and certainly discover the _Schematisme_ and
+_Texture_ even of these films, and of several other bodies, as we can these
+of Cork; there seems no probable reason to the contrary, but that we might
+as readily render the true reason of all their _Phaenomena_; as namely,
+what were the cause of the springingess, and toughness of some, both as to
+their flexibility and restitution. What, of the friability or brittleness
+of some others, and the like; but till such time as our _Microscope_, or
+some other means, enable us to discover the true _Schematism_ and _Texture_
+of all kinds of bodies, we must grope, as it were, in the dark, and onely
+ghess at the true reasons of things by similitudes and comparisons.
+
+But, to return to our Observation. I told several lines of these pores, and
+found that there were usually about threescore of these small Cells placed
+end-ways in the eighteenth part of an Inch in length, whence I concluded
+there must be neer eleven hundred of them, or somewhat more then a thousand
+in the length of an Inch, and therefore in a square Inch above a Million,
+or 1166400. and in a Cubick Inch, above twelve hundred Millions, or
+1259712000. a thing almost incredible, did not our _Microscope_ assure us
+of it by ocular demonstration; nay, did it not discover to us the pores of
+a body, which were they _diaphragm'd_, like those of Cork, would afford us
+in one Cubick Inch, more then ten times as many little Cells, as is evident
+in several charr'd Vegetables; so prodigiously curious are the works of
+Nature, that even these conspicuous pores of bodies, which seem to be the
+channels or pipes through which the _Succus nutritius_, or natural juices
+of Vegetables are convey'd, and seem to correspond to the veins, arteries
+and other Vessels in sensible creatures, that these pores I say, which seem
+to be the Vessels of nutrition to the vastest body in the World, are yet so
+exceeding small, that the _Atoms_ which _Epicurus_ fancy'd would go neer to
+prove too bigg to enter them, much more to constitute a fluid body in them.
+And how infinitely smaller then must be the Vessels of a Mite, or the pores
+of one of those little Vegetables I have discovered to grow on the
+back-side of a Rose-leaf, and shall anon more fully describe, whose bulk is
+many millions of times less then the bulk of the small shrub it grows on;
+and even that shrub, many millions of times less in bulk then several trees
+(that have heretofore grown in _England_, and are this day flourishing in
+other hotter Climates, as we are very credibly inform'd) if at least the
+pores of this small Vegetable should keep any such proportion to the body
+of it, as we have found these pores of other Vegetables to do to their
+bulk. But of these pores I have said more elsewhere.
+
+To proceed then, Cork seems to be by the transverse constitution of the
+pores, a kind of _Fungus_ or Mushrome, for the pores lie like so many Rays
+tending from the center, or pith of the tree, outwards; so that if you cut
+off a piece from a board of Cork transversly, to the flat of it, you will,
+as it were, split the pores, and they will appear just as they are
+express'd in the Figure B of the XI. _Scheme_. But if you shave off a very
+thin piece from this board, parallel to the plain of it, you will cut all
+the pores transversly, and they will appear almost as they are express'd in
+the Figure A, save onely the solid _Interstitia_ will not appear so thick
+as they are there represented.
+
+So that Cork seems to suck its nourishment from the subjacent bark of the
+Tree immediately, and to be a kind of excrescence, or a substance distinct
+from the substances of the entire Tree, something _analogus_ to the
+Mushrome, or Moss on other Trees, or to the hairs on Animals. And having
+enquir'd into the History of Cork, I find it reckoned as an excrescency of
+the bark of a certain Tree, which is distinct from the two barks that lie
+within it, which are common also to other trees; That 'tis some time before
+the Cork that covers the young and tender sprouts comes to be discernable;
+That it cracks, flaws, and cleaves into many great chaps, the bark
+underneath remaining entire; That it may be separated and remov'd from the
+Tree, and yet the two under-barks (such as are also common to that with
+other Trees) not at all injur'd, but rather helped and freed from an
+external injury. Thus _Jonstonus_ in _Dendrologia_, speaking _de Subere_,
+says, _Arbor est procera, Lignum est robustum, dempto cortice in aquis non
+fluitat, Cortice in orbem detracto juvatur, crascescens enim praestringit &
+strangulat, intra triennium iterum repletur: Caudex ubi adolescit crassus,
+cortex superior densus carnosus, duos digitos crassus, scaber, rimosus, &
+qui nisi detrahatur dehiscit, alioque subnascente expellitur, interior qui
+subest novellus ita rubet ut arbor minio picta videatur_. Which Histories,
+if well consider'd, and the tree, substance, and manner of growing, if well
+examin'd, would, I am very apt to believe, much confirm this my conjecture
+about the origination of Cork.
+
+Nor is this kind of Texture peculiar to Cork onely; for upon examination
+with my _Microscope_, I have found that the pith of an Elder, or almost any
+other Tree, the inner pulp or pith of the Cany hollow stalks of several
+other Vegetables: as of Fennel, Carrets, Daucus, Bur-docks, Teasels, Fearn,
+some kinds of Reeds, &c. have much such a kind of _Schematisme_, as I have
+lately shewn that of Cork, save onely that here the pores are rang'd the
+long-ways, or the same ways with the length of the Cane, whereas in Cork
+they are transverse.
+
+The pith also that fills that part of the stalk of a Feather that is above
+the Quil, has much such a kind of texture, save onely that which way soever
+I set this light substance, the pores seem'd to be cut transversly; so that
+I ghess this pith which fills the Feather, not to consist of abundance of
+long pores separated with Diaphragms, as Cork does, but to be a kind of
+solid or hardned froth, or a _congeries_ of very small bubbles consolidated
+in that form, into a pretty stiff as well as tough concrete, and that each
+Cavern, Bubble, or Cell, is distinctly separate from any of the rest,
+without any kind of hole in the encompassing films, so that I could no more
+blow through a piece of this kinde of substance, then I could through a
+piece of Cork, or the sound pith of an Elder.
+
+But though I could not with my _Microscope_, nor with my breath, nor any
+other way I have yet try'd, discover a passage out of one of those cavities
+into another, yet I cannot thence conclude, that therefore there are none
+such, by which the _Succus nutritius_, or appropriate juices of Vegetables,
+may pass through them; for, in several of those Vegetables, whil'st green,
+I have with my _Microscope_, plainly enough discover'd these Cells or Poles
+fill'd with juices, and by degrees sweating them out; as I have also
+observed in green Wood all those long _Microscopical_ pores which appear in
+Charcoal perfectly empty of any thing but Air.
+
+Now, though I have with great diligence endeavoured to find whether there
+be any such thing in those _Microscopical_ pores of Wood or Piths, as the
+_Valves_ in the heart, veins, and other passages of Animals, that open and
+give passage to the contain'd fluid juices one way, and shut themselves,
+and impede the passage of such liquors back again, yet have I not hitherto
+been able to say any thing positive in it; though, me thinks, it seems very
+probable, that Nature has in these passages, as well as in those of Animal
+bodies, very many appropriated Instruments and contrivances, whereby to
+bring her designs and end to pass, which 'tis not improbable, but that some
+diligent Observer, if help'd with better _Microscopes_, may in time detect.
+
+And that this may be so, seems with great probability to be argued from the
+strange _Phaenomena_ of sensitive Plants, wherein Nature seems to perform
+several Animal actions with the same _Schematism_ or _Orginization_ that is
+common to all Vegetables, as may appear by some no less instructive then
+curious Observations that were made by divers Eminent Members of the _Royal
+Society_ on some of these kind of Plants, whereof an account was delivered
+in to them by the most Ingenious and Excellent _Physician_, Doctor _Clark_,
+which, having that liberty granted me by that most Illustrious Society, I
+have hereunto adjoyn'd.
+
+_Observations on the _Humble_ and _Sensible Plants_ in _M Chiffin's_ Garden
+in Saint _James_'s Park, made _August_ the _9th, 1661_._ _Present, the_
+Lord _Brouncker_, Sr. _Robert Moray_, Dr. _Wilkins_, Mr. _Evelin_, Dr.
+_Henshaw_, _and_ Dr. _Clark_.
+
+    There are four Plants, two of which are little shrub Plants, with a
+    little short stock, about an Inch above the ground, from whence are
+    spread several sticky branches, round, streight, and smooth in the
+    distances between the Sprouts, but just under the Sprouts there are two
+    sharp thorny prickles, broad in the letting on, as in the Bramble, one
+    just under the Sprout, the other on the opposite side of the branch.
+
+    [14]The distances betwixt the Sprouts are usually something more then
+    an Inch, and many upon a Branch, according to its length, and they grew
+    so, that if the lower Sprout be on the left side of the Branch, the
+    next above is on the right, and so to the end, not sprouting by pairs.
+
+    At the end of each Sprout are generally four sprigs, two at the
+    Extremity, and one on each side, just under it. At the first sprouting
+    of these from the Branch to the Sprig where the leaves grow, they are
+    full of little short white hairs, which wear off as the leaves grow,
+    and then they are smooth as the Branch.
+
+    Upon each of these sprigs, are, for the most part, eleven pair of
+    leaves, neatly set into the uppermost part of the little sprig, exactly
+    one against another, as it were in little _articulations_, such as
+    Anatomists call _Enarthrosis_, where the round head of a Bone is
+    received into another fitted for its motion; and standing very fitly to
+    shut themselves and touch, the pairs just above them closing somewhat
+    upon them, as in the shut sprig; so is the little round _Pedunculus_ of
+    this leaf fitted into a little cavity of the sprig, visible to the eye
+    in a sprig new pluck'd, or in a sprig withered on the Branch, from
+    which the leaves easily fall by touching.
+
+    The leaf being almost an oblong square, and set into the _Pedunculus_,
+    at one of the lower corners, receiveth from that not onely a _Spine_,
+    as I may call it, which, passing through the leaf, divides it so
+    length-ways that the outer-side is broader then the inner next the
+    sprig, but little _fibres_ passing obliquely towards the opposite
+    broader side, seem to make it here a little muscular, and fitted to
+    move the whole leaf, which, together with the whole sprig, are set full
+    with little short whitish hairs.
+
+    One of these Plants, whose branch seem'd to be older and more grown
+    then the other, onely the tender Sprouts of it, after the leaves are
+    shut, fall and hang down; of the other, the whole branches fall to the
+    ground, if the Sun shine very warm, upon the first taking off the
+    Glass, which I therefore call the _humble Plant_.
+
+    The other two, which do never fall, nor do any of their branches flagg
+    and hang down, shut not their leaves, but upon somewhat a hard stroke;
+    the stalks seem to grow up from a root, and appear more _herbaceous_,
+    they are round and smooth, without any prickle, the Sprouts from them
+    have several pairs of sprigs, with much less leaves then the other on
+    them, and have on each sprig generally seventeen pair.
+
+    Upon touching any of the sprigs with leaves on, all the leaves on that
+    sprig contracting themselves by pairs, joyned their upper superficies
+    close together.
+
+    Upon the dropping a drop of _Aqua fortis_ on the sprig betwixt the
+    leaves, ff all the leaves above shut presently, those below by pairs
+    successively after, and by the lower leaves of the other branches, ll,
+    kk, &c. and so every pair successively, with some little distance of
+    time betwixt, to the top of each sprig, and so they continu'd shut all
+    the time we were there. But I returning the next day, and several days
+    since, found all the leaves dilated again on two of the sprigs; but
+    from ff, where the _Aqua fortis_ had dropped upwards, dead and
+    withered; but those below on the same sprig, green, and closing upon
+    the touch, and are so to this day, _August_ 14.
+
+    With a pair of Scissers, as suddenly as it could be done, one of the
+    leaves bb was clipped off in the middle, upon which that pair, and the
+    pair above, closed presently, after a little interval, dd, then ee, and
+    so the rest of the pairs, to the bottom of the sprig, and then the
+    motion began in the lower pairs, ll, on the other sprigs, and so shut
+    them by pairs upwards, though not with such distinct distances.
+
+    Under a pretty large branch with its sprigs on, there lying a large
+    Shell betwixt two and three Inches below it, there was rubbed on a
+    strong sented oyl, after a little time all the leaves on that sprig
+    were shut, and so they continued all the time of our stay there, but at
+    my returne the next day, I found the position of the Shell alter'd, and
+    the leaves expanded as before, and closing upon the touch.
+
+    Upon the application of the Sun-beams by a Burning-glass, the more
+    _humble Plant_ fell, the other shut their leaves.
+
+    We could not so apply the smoak of _Sulpher_, as to have any visible
+    effect from that, at two or three times trial; but on another trial,
+    the smoak touching the leaves, it succeeded.
+
+    The _humble Plant_ fell upon taking off the Glass wherewith it was
+    covered.
+
+    Cutting off one of the little Sprouts, two or three drops of liquor
+    were thrust out of the part from whence that was cut, very cleer, and
+    pellucid, of a bright greenish colour, tasting at first a little
+    bitterish, but after leaving a licorish-like taste in my mouth.
+
+    Since, going two or three times when it was cold, I took the Glasses
+    from the more _humble Plant_, and it did not fall as formerly, but shut
+    its leaves onely. But coming afterwards, when the Sun shone very warm,
+    as soon as it was taken off, it fell as before.
+
+    Since I pluck'd off another sprig, whose leaves were all shut, and had
+    been so some time, thinking to observe the liquor should come from that
+    I had broken off, but finding none, though with pressing, to come, I,
+    as dexterously as I could, pull'd off one whose leaves were expanded,
+    and then had upon the shutting of the leaves, a little of the mention'd
+    liquor, from the end of the sprig I had broken from the Plant. And this
+    twice successively, as often almost as I durst rob the Plant.
+
+    But my curiosity carrying me yet further, I cut off one of the harder
+    branches of the stronger Plant, and there came of the liquor, both from
+    that I had cut, and that I had cut it from, without pressure.
+
+    Which made me think, that the motion of this Plant upon touching, might
+    be from this, that there being a constant _intercourse_ betwixt every
+    part of this Plant and its root, either by a _circulation_ of this
+    liquor, or a constant pressing of the subtiler parts of it to every
+    extremity of the Plant. Upon every pressure, from whatsoever it
+    proceeds, greater then that which keeps it up, the subtile parts of
+    this liquor are thrust downwards, towards its _articulations_ of the
+    leaves, where, not having room presently to get into the sprig, the
+    little round _pedunculus_, from whence the _Spine_ and those oblique
+    _Fibres_ I mentioned rise, being dilated, the _Spine_ and _Fibres_
+    (being continued from it) must be contracted and shortned, and so draw
+    the leaf upwards to joyn with its fellow in the same condition with it
+    self, where, being closed, they are held together by the implications
+    of the little whitish hair, as well as by the still retreating liquor,
+    which distending the _Fibres_ that are continued lower to the branch
+    and root, shorten them above; and when the liquor is so much forced
+    from the Sprout, whose _Fibres_ are yet tender, and not able to support
+    themselves, but by that tensness which the liquor filling their
+    _interstices_ gives them, the Sprout hangs and flags.
+
+    But, perhaps, he that had the ability and leisure to give you the exact
+    _Anatomy_ of this pretty Plant, to shew you its _Fibres_, and visible
+    _Canales_, through which this fine liquor circulateth, or is moved, and
+    had the faculty of better and more copiously expressing his
+    Observations and conceptions, such a one would easily from the motion
+    of this liquor, solve all the _Phaenomena_, and would not fear to
+    affirm, that it is no obscure sensation this Plant hath. But I have
+    said too much, I humbly submit, and am ready to stand corrected.
+
+I have not yet made so full and satisfactory Observations as I desire on
+this Plant, which seems to be a Subject that will afford abundance of
+information. But as farr as I have had opportunity to examine it, I have
+discovered with my _Microscope_ very curious structures and contrivances;
+but designing much more accurate examinations and trials, both with my
+_Microscope_, and otherwise, as soon as the season will permit, I shall not
+till then add any thing of what I have already taken notice of; but as farr
+as I have yet observ'd, I judge the motion of it to proceed from causes
+very differing from those by which Gut-strings, or Lute-strings, the beard
+of a wilde _Oat_, or the beard of the Seeds of _Geranium_, _Mosscatum_, or
+_Musk-grass_ and other kinds of _Cranes-bill_, move themselves. Of which I
+shall add more in the subsequent Observations on those bodies.
+
+       *       *       *       *       *
+
+
+Observ. XIX. _Of a _Plant_ growing in the blighted or yellow specks of
+_Damask-rose-leaves_, _Bramble-leaves_, and some other kind of leaves._
+
+I have for several years together, in the Moneths of _June_, _July_,
+_August_, and _September_ (when any of the green leaves of _Roses_ begin to
+dry and grow yellow) observ'd many of them, especially the leaves of the
+old shrubs of _Damask Roses_, all bespecked with yellow stains; and the
+undersides just against them, to have little yellow hillocks of a gummous
+substance, and several of them to have small black spots in the midst of
+those yellow ones, which, to the naked eye, appear'd no bigger then the
+point of a Pin, or the smallest black spot or tittle of Ink one is able to
+make with a very sharp pointed Pen.
+
+Examining these with a _Microscope,_ I was able plainly to distinguish, up
+and down the surface, several small yellow knobs, of a kind of yellowish
+red gummy substance, out of which I perceiv'd there sprung multitudes of
+little cases or black bodies like Seed-cods, and those of them that were
+quite without the hillock of Gumm, disclos'd themselves to grow out of it
+with a small Straw-colour'd and transparent stem, the which seed and stem
+appear'd very like those of common Moss (which I elsewhere describe) but
+that they were abundantly less, many hundreds of them being not able to
+equalize one single seed Cod of Moss.
+
+I have often doubted whether they were the seed Cods of some little Plant,
+or some kind of small Buds, or the Eggs of some very small Insect, they
+appear'd of a dark brownish red, some almost quite black, and of a Figure
+much resembling the seed-cod of Moss, but their stalks on which they grew
+were of a very fine transparent substance, almost like the stalk of mould,
+but that they seem'd somewhat more yellow.
+
+That which makes me to suppose them to be Vegetables, is for that I
+perceiv'd many of those hillocks bare or destitute, as if those bodies lay
+yet conceal'd, as G. In others of them, they were just springing out of
+their gummy hillocks, which all seem'd to shoot directly outwards, as at A.
+In others, as at B, I found them just gotten out, with very little or no
+stalk, and the Cods of an indifferent cize; but in others, as C, I found
+them begin to have little short stalks, or stems; in others, as D, those
+stems were grown bigger, and larger; and in others, as at E, F, H, I, K, L,
+&c. those stems and Cods were grown a great deal bigger, and the stalks
+were more bulky about the root, and very much taper'd towards the top, as
+at F and L is most visible.
+
+I did not find that any of them had any seed in them, or that any of them
+were hollow, but as they grew bigger and bigger, I found those heads or
+Cods begin to turn their tops towards their roots, in the same manner as I
+had observ'd that of Moss to do; so that in all likelihood, Nature did
+intend in that posture, what she does in the like seed-cods of greater
+bulk, that is, that the seed, when ripe, should be shaken out and dispersed
+at the end of it, as we find in Columbine Cods, and the like.
+
+The whole Oval OOOO in the second _Figure_ of the 12. _Scheme_ represents a
+small part of a Rose leaf, about the bigness of the little Oval in the
+hillock, C, marked with the Figure X. in which I have not particularly
+observ'd all the other forms of the surface of the Rose-leaf, as being
+little to my present purpose.
+
+Now, if these Cods have a seed in them so proportion'd to the Cod, as thole
+of _Pinks_, and _Carnations_, and _Columbines_, and the like, how
+unimaginably small must each of those seeds necessarily be, for the whole
+length of one of the largest of those Cods was not 1/500 part of an Inch;
+some not above 1/1000, and therefore certainly, very many thousand of them
+would be unable to make a bulk that should be visible to the naked eye; and
+if each of these contain the Rudiments of a young Plant of the same kind,
+what must we say of the pores and constituent parts of that?
+
+The generation of this Plant seems in part, ascribable to a kind of
+_Mildew_ or _Blight_, whereby the parts of the leaves grow scabby, or
+putrify'd, as it were, so as that the moisture breaks out in little scabs
+or spots, which, as I said before, look like little knobs of a red gummous
+substance.
+
+From this putrify'd scabb breaks out this little Vegetable; which may be
+somewhat like a _Mould_ or _Moss_; and may have its _equivocal_ generation
+much after the same manner as I have supposed _Moss_ or _Mould_ to have,
+and to be a more simple and uncompounded kind of vegetation, which is set a
+moving by the _putrifactive_ and _fermentative_ heat, joyn'd with that of
+the ambient aerial, when (by the putrifaction and decay of some other parts
+of the vegetable, that for a while staid its progress) it is unfetter'd and
+left at liberty to move in its former course, but by reason of its
+_regulators_, moves and acts after quite another manner then it did when a
+_coagent_ in the more compounded _machine_ of the more perfect Vegetable.
+
+And from this very same Principle, I imagine the _Misleto_ of Oaks, Thorns,
+Appletrees, and other Trees, to have its original: It seldom or never
+growing on any of those Trees, till they begin to wax decrepid, and decay
+with age, and are pester'd with many other infirmities.
+
+Hither also may be referr'd those multitudes and varieties of _Mushroms_,
+such as that, call'd _Jews-ears_, all sorts of _gray_ and _green_ Mosses,
+&c. which infest all kind of Trees, shrubs, and the like, especially when
+they come to any bigness. And this we see to be very much the method of
+Nature throughout its operations, _putrifactive Vegetables_ very often
+producing a Vegetable of a much less compounded nature, and of a much
+inferiour tribe; and _putrefactive_ animal substances degenerating into
+some kind of animal production of a much inferiour rank, and of a more
+simple nature.
+
+Thus we find the humours and substances of the body, upon _putrifaction_,
+to produce strange kinds of moving Vermine: _the putrifaction_ of the
+slimes and juices of the Stomack and Guts, produce Worms almost like
+Earth-worms, the Wheals in childrens hands produce a little Worm, call'd a
+_Wheal-worm_: The bloud and milk, and other humours, produce other kinds of
+Worms, at least, if we may believe what is deliver'd to us by very famous
+Authors; though, I confess, I have not yet been able to discover such my
+self.
+
+And whereas it may seem strange that _Vinegar_, _Meal_, musty _Casks_, &c.
+are observ'd to breed their differing kinds of Insects, or living
+creatures, whereas they being Vegetable substances, seem to be of an
+inferiour kind, and so unable to produce a creature more noble, or of a
+more compounded nature then they themselves are of, and so without some
+concurrent seminal principle, may be thought utterly unfit for such an
+operation; I must add, that we cannot presently positively say, there are
+no animal substances, either mediately, as by the soil or fatning of the
+Plant from whence they sprung, or more immediately, by the real mixture or
+composition of such substances, join'd with them; or perchance some kind of
+Insect, in such places where such kind of _putrifying_ or _fermenting_
+bodies are, may, by a certain instinct of nature, eject some sort of
+seminal principle, which cooperating with various kinds of _putrifying_
+substances, may produce various kinds of Insects, or Animate bodies: For we
+find in most sorts of those lower degrees of Animate bodies, that the
+_putrifying_ substances on which these Eggs, Seeds, or seminal principles
+are cast by the Insect, become, as it were, the _Matrices_ or Wombs that
+conduce very much to their generation, and may perchance also to their
+variation and alteration, much after the same manner, as, by strange and
+unnatural copulations, several new kinds of Animals are produc'd, as
+_Mules_, and the like, which are usually call'd Monstrous, because a little
+unusual, though many of them have all their principal parts as perfectly
+shap'd and adapted for their peculiar uses, as any of the most perfect
+Animals. If therefore the _putrifying_ body, on which any kind of seminal
+or vital principle chances to be cast, become somewhat more then meerly a
+nursing and fostering helper in the generation and production of any kind
+of Animate body, the more neer it approaches the true nature of a Womb, the
+more power will it have on the by-blow it incloses. But of this somewhat
+more in the description of the _Water-gnat_. Perhaps some more accurate
+Enquiries and Observations about these matters might bring the Question to
+some certainty, which would be of no small concern in Natural Philosophy.
+
+But that _putrifying_ animal substances may produce animals of an inferior
+kind, I see not any so very great a difficulty, but that one may, without
+much absurdity, admit: For as there may be multitudes of contrivances that
+go to the making up of one compleat Animate body; so, That some of those
+_coadjutors_, in the perfect existence and life of it, may be vitiated, and
+the life of the whole destroyed, and yet several of the constituting
+contrivances remain intire, I cannot think it beyond imagination or
+possibility; no more then that a like accidental process, as I have
+elswhere hinted, may also be supposed to explicate the method of Nature in
+the _Metamorphosis_ of Plants. And though the difference between a Plant
+and an Animal be very great, yet I have not hitherto met with any so
+_cogent_ an Argument, as to make me positive in affirming these two to be
+altogether _Heterogeneous_ and of quite differing kinds of Nature: And
+besides, as there are many _Zoophyts_, and sensitive Plants (divers of
+which I have seen, which are of a middle nature, and seem to be Natures
+transition from one degree to another, which may be observ'd in all her
+other passages, wherein she is very seldom observ'd to leap from one step
+to another) so have we, in some Authors, Instances of Plants turning into
+Animals, and Animals into Plants, and the like; and some other very strange
+(because unheeded) proceedings of Nature; something of which kind may be
+met with, in the description of the _Water-Gnat_, though it be not
+altogether so direct to the present purpose.
+
+But to refer this Discourse of Animals to their proper places, I shall add,
+that though one should suppose, or it should be prov'd by Observations;
+that several of these kinds of Plants are accidentally produc'd by a casual
+_purifaction_, I see not any great reason to question, but that,
+notwithstanding its own production was as 'twere casual, yet it may
+germinate and produce seed, and by it propagate its own, that is, a new
+Species. For we do not know, but that the Omnipotent and All-wise Creator
+might as directly design the structure of such a Vegetable, or such an
+Animal to be produc'd out of such or such a _putrifaction_ or change of
+this or that body, towards the constitution or structure of which, he knew
+it necessary, or thought it fit to make it an ingredient; as that the
+digestion or moderate heating of an Egg, either by the Female, or the Sun,
+or the heat of the Fire, or the like, should produce this or that Bird; or
+that _Putrifactive_ and warm steams should, out of the blowings, as they
+call them, that is, the Eggs of a Flie, produce a living Magot, and that,
+by degrees, be turn'd into an _Aurelia_, and that, by a longer and a
+proportion'd heat, be _transmuted_ into a Fly. Nor need we therefore to
+suppose it the more imperfect in its kind, then the more compounded
+Vegetable or Animal of which it is a part; for he might as compleatly
+furnish it with all kinds of contrivances necessary for its own existence,
+and the propagation of its own Species, and yet make it a part of a more
+compounded body: as a Clock-maker might make a Set of Chimes to be a part
+of a Clock, and yet, when the watch part or striking part are taken away,
+and the hindrances of its motion remov'd, this chiming part may go as
+accurately, and strike its tune as exactly, as if it were still a part of
+the compounded _Automaton_. So, though the original cause, or seminal
+principle from which this minute Plant on Rose leaves did spring; were,
+before the corruption caus'd by the Mill-dew, a component part of the leaf
+on which it grew, and did serve as a _coagent_ in the production and
+constitution of it, yet might it be so consummate, as to produce a seed
+which might have a power of propagating the same species: the works of the
+Creator seeming of such an excellency, that though they are unable to help
+to the perfecting of the more compounded existence of the greater Plant or
+Animal, they may have notwithstanding an ability of acting singly upon
+their own internal principle, so as to produce a Vegetable body, though of
+a less compounded nature, and to proceed so farr in the method of other
+Vegetables, as to bear flowers and seeds, which may be capabale of
+propagating the like. So that the little cases which appear to grow on the
+top of the slender stalks, may, for ought I know, though I should suppose
+them to spring from the perverting of the usual course of the parent
+Vegetable, contain a seed, which, being scatter'd on other leaves of the
+same Plant, may produce a Plant of much the same kind.
+
+Nor are Damask-Rose leaves the onely leaves that produce these kinds of
+Vegetable sproutings; for I have observ'd them also in several other kinds
+of Rose leaves, and on the leaves of several sorts of Briers, and on
+Bramble leaves they are oftentimes to be found in very great clusters; so
+that I have found in one cluster, three, four, or five hundred of them,
+making a very conspicuous black spot or scab on the back side of the leaf.
+
+       *       *       *       *       *
+
+
+Observ. XX. _Of _blue Mould_, and of the first Principles of Vegetation
+arising from _Putrefaction_._
+
+The Blue and White and several kinds of hairy mouldy spots, which are
+observable upon divers kinds of _putrify'd_ bodies, whether Animal
+substances, or Vegetable, such as the skin, raw or dress'd, flesh, bloud,
+humours, milk, green Cheese, &c. or rotten sappy Wood, or Herbs, Leaves,
+Barks, Roots, &c. of Plants, are all of them nothing else but several kinds
+of small and variously figur'd Mushroms, which, from convenient materials
+in those _putrifying_ bodies, are, by the concurrent heat of the Air,
+excited to a certain kind of vegetation, which will not be unworthy our
+more serious speculation and examination, as I shall by and by shew. But,
+first, I must premise a short description of this _Specimen_, which I have
+added of this Tribe, in the first Figure of the XII. _Scheme_, which is
+nothing else but the appearance of a small white spot of hairy mould,
+multitudes of which I found to bespeck & whiten over the red covers of a
+small book, which, it seems, were of Sheeps skin, that being more apt to
+gather mould, even in a dry and clean room, then other leathers. These
+spots appear'd, through a good _Microscope_, to be a very pretty shap'd
+Vegetative body, which, from almost the same part of the Leather, shot out
+multitudes of small long cylindrical and transparent stalks, not exactly
+streight, but a little bended with the weight of a round and white knob
+that grew on the top of each of them; many of these knobs I observ'd to be
+very round, and of a smooth surface, such as A, A, &c. others smooth
+likewise, but a little oblong, as B; several of them a little broken, or
+cloven with chops at the top, as C; others flitter'd as 'twere, or flown
+all to pieces, as D, D. The whole substance of these pretty bodies was of a
+very tender constitution, much like the substance of the softer kind of
+common white Mushroms, for by touching them with a Pin, I found them to be
+brused and torn; they seem'd each of them to have a distinct root of their
+own; for though they grew neer together in a cluster, yet I could perceive
+each stem to rise out of a distinct part or pore of the Leather; some of
+these were small and short, as seeming to have been but newly sprung up, of
+these the balls were for the most part round, others were bigger, and
+taller, as being perhaps of a longer growth, and of these, for the most
+part, the heads were broken, and some much wasted, as E; what these heads
+contain'd I could not perceive; whether they were knobs and flowers, or
+seed cases, I am not able to say, but they seem'd most likely to be of the
+same nature with those that grow on Mushroms, which they did, some of them,
+not a little resemble.
+
+Both their smell and taste, which are active enough to make a sensible
+impression upon those organs, are unpleasant and noisome.
+
+I could not find that they would so quickly be destroy'd by the actual
+flame of a Candle, as at first sight of them I conceived they would be, but
+they remain'd intire after I had past that part of the Leather on which
+they stuck three or four times through the flame of a Candle; so that, it
+seems they are not very apt to take fire, no more then the common white
+Mushroms are when they are sappy.
+
+There are a multitude of other shapes, of which these _Microscopical_
+Mushroms are figur'd, which would have been a long Work to have described,
+and would not have suited so well with my design in this Treatise, onely,
+amongst the rest, I must not forget to take notice of one that was a little
+like to, or resembled, a Spunge, consisting of a multitude of little
+Ramifications almost as that body does, which indeed seems to be a kind of
+Water-Mushrom, of a very pretty texture, as I else-where manifest. And a
+second, which I must not omit, because often mingled, and neer adjoining to
+these I have describ'd, and this appear'd much like a Thicket of bushes, or
+brambles, very much branch'd, and extended, some of them, to a great
+length, in proportion to their Diameter, like creeping brambles.
+
+The manner of the growth and formation of this kind of Vegetable, is the
+third head of Enquiry, which, had I time, I should follow: the figure and
+method of Generation in this concrete seeming to me, next after the Enquiry
+into the formation, figuration; or chrystalization of Salts, to be the most
+simple, plain, and easie; and it seems to be a _medium_ through which he
+must necessarily pass, that would with any likelihood investigate the
+_forma informans_ of Vegetables: for as I think that he shall find it a
+very difficult task, who undertakes to discover the form of Saline
+crystallizations, without the consideration and prescience of the nature
+and reason of a Globular form, and as difficult to explicate this
+configuration of Mushroms, without the previous consideration of the form
+of Salts; so will the enquiry into the forms of Vegetables be no less, if
+not much more difficult, without the fore-knowledge of the forms of
+Mushroms, these several Enquiries having no less dependance one upon
+another then any select number of Propositions in Mathematical Elements may
+be made to have.
+
+Nor do I imagine that the skips from the one to another will be found very
+great, if beginning from fluidity, or body without any form, we descend
+gradually, till we arrive at the highest form of a bruite Animal's Soul,
+making the steps or foundations of our Enquiry, _Fluidity_, _Orbiculation_,
+_Fixation_, _Angulization_, or _Crystallization Germination_ or
+_Ebullition_, _Vegetation_, _Plantanimation_, _Animation_, _Sensation_,
+_Imagination_.
+
+Now, that we may the better proceed in our Enquiry, It will be requisite to
+consider:
+
+First, that Mould and Mushroms require no seminal property, but the former
+may be produc'd at any time from any kind of _putrifying_ Animal, or
+Vegetable Substance, as Flesh, &c. kept moist and warm, and the latter, if
+what _Mathiolus_ relates be true, of making them by Art, are as much within
+our command, of which Matter take the _Epitomie_ which Mr. _Parkinson_ has
+deliver'd in his _Herbal_, in his Chapter of _Mushroms_, because I have not
+_Mathiolus_ now by me: _Unto these Mushroms_ (saith he) _may also be
+adjoyn'd those which are made of Art (whereof _Mathiolus_ makes mention)
+that grow naturally among certain stones in _Naples_, and that the stones
+being digg'd up, and carried to _Rome_, and other places, where they set
+them in their Wine Cellars, covering them with a little Earth, and
+sprinkling a little warm water thereon, would within four days produce
+Mushroms fit to be eaten, at what time one will: As also that Mushroms may
+be made to grow at the foot of a wilde _Poplar Tree_, within four days
+after, warm water wherein some leaves have been dissolv'd shall be pour'd
+into the Root (which must be slit) and the stock above ground._
+
+Next, that as Mushroms may be generated without seed, so does it not appear
+that they have any such thing as seed in any part of them; for having
+considered several kinds of them, I could never find any thing in them that
+I could with any probability ghess to be the seed of it, so that it does
+not as yet appear (that I know of) that Mushroms may be generated from a
+seed, but they rather seem to depend merely upon a convenient constitution
+of the matter out of which they are made, and a concurrence of either
+natural or artificial heat.
+
+Thirdly, that by several bodies (as Salts and Metals both in Water and in
+the air, and by several kinds of sublimations in the Air) actuated and
+guided with a congruous heat, there may be produc'd several kinds of bodies
+as curiously, if not of a more compos'd Figure; several kinds of rising or
+Ebulliating Figures seem to manifest; as witness the shooting in the
+Rectification of spirits of _Urine_, _Hart-horn_, _Bloud_, &c. witness also
+the curious branches of evaporated dissolutions, some of them against the
+sides of the containing Jar: others standing up, or growing an end, out of
+the bottom, of which I have taken notice of a very great variety. But above
+all the rest, it is a very pretty kind of Germination which is afforded us
+in the Silver Tree, the manner of making which with Mercury and Silver, is
+well known to the Chymists, in which there is an Ebullition or Germination,
+very much like this of Mushroms, if I have been rightly inform'd of it.
+
+Fourthly, I have very often taken notice of, and also observ'd with a
+_Microscope_, certain excrescencies or Ebullitions in the snuff of a
+Candle, which, partly from the sticking of the smoaky particles as they are
+carryed upwards by the current of the rarify'd Air and flame, and partly
+also from a kind of Germination or Ebullition of some actuated unctuous
+parts which creep along and filter through some small string of the Week,
+are formed into pretty round and uniform heads, very much resembling the
+form of hooded Mushroms, which, being by any means expos'd to the fresh
+Air, or that air which encompasses the flame, they are presently lick'd up
+and devour'd by it, and vanish.
+
+The reason of which _Phaenomenon_ seems to me, to be no other then this:
+
+That when a convenient thread of the Week is so bent out by the sides of
+the snuff that are about half an Inch or more, remov'd above the bottom, or
+lowest part of the flame, and that this part be wholly included in the
+flame; the Oyl (for the reason of filtration, which I have elsewhere
+rendred) being continualy driven up the snuff is driven likewise into this
+ragged bended-end, and this being remov'd a good distance, as half an Inch
+or more, above the bottom of the flame, the parts of the air that passes by
+it, are already, almost satiated with the dissolution of the boiling
+unctuous steams that issued out below, and therefore are not onely glutted,
+that is, can dissolve no more then what they are already acting upon, but
+they carry up with them abundance of unctuous and sooty particles, which
+meeting with that rag of the Week, that is plentifully fill'd with Oyl, and
+onely spends it as fast as it evaporates, and not at all by dissolution or
+burning, by means of these steamy parts of the filterated Oyl issuing out
+at the sides of this ragg, and being inclos'd with an air that is already
+satiated and cannot prey upon them nor burn them, the ascending sooty
+particles are stay'd about it and fix'd, so as that about the end of that
+ragg or filament of the snuff, whence the greatest part of the steams
+issue, there is conglobated or fix'd a round and pretty uniform cap, much
+resembling the head of a Mushrom, which, if it be of any great bigness, you
+may observe that its underside will be bigger then that which is above the
+ragg or stem of it; for the Oyl that is brought into it by filtration,
+being by the bulk of the cap a little shelter'd from the heat of the flame,
+does by that means issue as much out beneath from the stalk or downwards,
+as it does upwards, and by reason of the great access of the adventitious
+smoak from beneath, it increases most that way. That this may be the true
+reason of this _Phaenomenon_, I could produce many Arguments and
+Experiments to make it probable: As,
+
+First, that the _Filtration_ carries the Oyl to the top of the Week, at
+least as high as these raggs, is visible to one that will observe the snuff
+of a burning Candle with a _Microscope_, where he may see an Ebullition or
+bubbling of the Oyl, as high as the snuff looks black.
+
+Next, that it does steam away more then burn; I could tell you of the dim
+burning of a Candle, the longer the snuff be which arises from the
+abundance of vapours out of the higher parts of it.
+
+And, thirdly, that in the middle of the flame of the Candle, neer the top
+of the snuff, the fire or dissolving principle is nothing neer so strong,
+as neer the bottom and out edges of the flame, which may be observ'd by the
+burning asunder of a thread, that will first break in those parts that the
+edges of the flame touch, and not in the middle.
+
+And I could add several Observables that I have taken notice of in the
+flame of a Lamp actuated with Bellows, and very many others that confirm me
+in my opinion, but that it is not so much to my present purpose, which is
+onely to consider this concreet in the snuff of a Candle, so farr as it has
+any resemblance of a Mushrom, to the consideration of which, that I may
+return, I say, we may also observe:
+
+In the fifth place, that the droppings or trillings of Lapidescent waters
+in Vaults under ground, seem to constitute a kind of _petrify'd_ body,
+form'd almost like some kind of Mushroms inverted, in so much that I have
+seen some knobb'd a little at the lower end, though for the most part,
+indeed they are otherwise shap'd, and taper'd towards the end; the
+generation of which seems to be from no other reason but this, that the
+water by soaking through the earth and Lime (for I ghess that substance to
+add much to it _petrifying_ quality) does so impregnate it self with stony
+particles, that hanging in drops in the roof of the Vault, by reason that
+the soaking of the water is but slow, it becomes expos'd to the Air, and
+thereby the outward part of the drop by degrees grows hard, by reason that
+the water gradually evaporating the stony particles neer the outsides of
+the drop begin to touch, and by degrees, to dry and grow closer together,
+and at length constitute a crust or shell about the drop; and this soaking
+by degrees, being more and more supply'd, the drop grows longer and longer,
+and the sides harden thicker and thicker into a Quill or Cane, and at
+length, that hollow or pith becomes almost stop'd up, and solid: afterwards
+the soaking of the _petrifying_ water, finding no longer a passage through
+the middle, bursts out, and trickles down the outside, and as the water
+evaporates, leaves new superinduc'd shells, which more and more swell the
+bulk of those Iceicles, and because of the great supply from the Vault, of
+_petrifying_ wafer, those bodies grow bigger and bigger next to the Vault,
+and taper or sharpen towards the point; for the access from the arch of the
+Vault being but very slow, and consequently the water being spread very
+thinly over the surface of the Iceicle, the water begins to settle before
+it can reach to the bottom, or corner end of it; whence, if you break one
+of these, you would almost imagine it a stick of Wood _petrify'd_, it
+having so pretty a resemblance of pith and grain, and if you look on the
+outside of a piece, or of one whole, you would think no less, both from its
+vegetable roundness and tapering form; but whereas all Vegetables are
+observ'd to shoot and grow perpendicularly upwards, this does shoot or
+propend directly downwards.
+
+By which last Observables, we see that there may be a very pretty body
+shap'd and concreeted by Mechanical principles, without the least shew or
+probability of any other seminal _formatrix_.
+
+And since we find that the great reason of the _Phaenomena_ of this pretty
+_petrifaction_, are to be reduc'd from the gravity of a fluid and pretty
+volatil body impregnated with stony particles, why may not the _Phaenomena_
+of Ebullition or Germination be in part possibly enough deduc'd from the
+levity of an impregnated liquor, which therefore perpendicularly ascending
+by degrees, evaporates and leaves the more solid and fix'd parts behind in
+the form of a Mushrom, which is yet further diversify'd and specificated by
+the forms of the parts that impregnated the liquor, and compose or help to
+constitute the Mushrom.
+
+That the foremention'd Figures of growing Salts, and the Silver Tree, are
+from this principle, I could very easily manifest, but that I have not now
+a convenient opportunity of following it, nor have I made a sufficient
+number of Experiments and Observations to propound, explicate, and prove so
+usefull a _Theory_ as this of Mushroms: for, though the contrary principle
+to that of _petrify'd_ Iceicles may be in part a cause, yet I cannot but
+think, that there is somewhat a more complicated caufe, though yet
+Mechanical, and possible to be explain'd.
+
+We therefore have further to enquire of it, what makes it to be such a
+liquor, and to ascend, whether the heat of the Sun and Air, or whether that
+_firmentiation_ and _putrifaction_, or both together; as also whether there
+be not a third or fourth; whether a Saline principle be not a considerable
+agent in this business also as well as heat; whether also a fixation,
+precipitation or settling of certain parts out of the aerial menstruum may
+not be also a considerable coadjutor in the business. Since we find that
+many pretty beards _stiriae_ of the particles of Silver may be precipitated
+upon a piece of Brass put into a _solution_ of Silver very much diluted
+with fair water, which look not unlike a kind of mould or hoar upon that
+piece of metal; and the hoar frost looks like a kind of mould; and whether
+there may not be several others that do concurr to the production of a
+Mushrom, having not yet had sufficient time to prosecute according to my
+desires, I must referr this to a better opportunity of my own, or leave and
+recommend it to the more diligent enquiry and examination of such as can be
+masters both of leisure and conveniencies for such an Enquiry.
+
+And in the mean time, I must conclude, that as far as I have been able to
+look into the nature of this Primary kind of life and vegetation, I cannot
+find the least probable argument to perswade me there is any other
+concurrent cause then such as is purely Mechanical, and that the effects or
+productions are as necessary upon the concurrence of those causes as that a
+Ship, when the Sails are hoist up, and the Rudder is set to such a
+position, should, when the Wind blows, be mov'd in such a way or course to
+that or t'other place; Or, as that the brused Watch, which I mention in the
+description of Moss, should, when those parts which hindred its motion were
+fallen away, begin to move, but after quite another manner then it did
+before.
+
+       *       *       *       *       *
+
+
+Observ. XXI. _Of _Moss_, and several other small-vegetative Substances._
+
+Moss is a Plant, that the wisest of Kings thought neither unworthy his
+speculation, nor his Pen, and though amongst Plants it be in bulk one of
+the smallest, yet it is not the least considerable: For, as to its shape,
+it may compare for the beauty of it with any Plant that grows, and bears a
+much bigger breadth; it has a root almost like a seedy Parsnep, furnish'd
+with small strings and suckers, which are all of them finely branch'd, like
+those of the roots of much bigger Vegetables; out of this springs the stem
+or body of the Plant, which is somewhat _Quadrangular_, rather then
+_Cylindrical_, most curiously _fluted_ or lining with small creases, which
+run, for the most part, _parallel_ the whole stem; on the sides of this are
+close and thick set, a multitude of fair, large, well-shap'd leaves, some
+of them of a rounder, others of a longer shape, according as they are
+younger or older when pluck'd; as I ghess by this, that those Plants that
+had the stalks growing from the top of them, had their leaves of a much
+longer shape, all the surface of each side of which, is curiously cover'd
+with a multitude of little oblong transparent bodies, in the manner as you
+see it express'd in the leaf B, in the XIII. _Scheme_.
+
+This Plant, when young and springing up, does much resemble a Housleek,
+having thick leaves, almost like that, and seems to be somwhat of kin to it
+in other particulars; also from the top of the leaves, there shoots out a
+small white and transparent hair, or thorn: This stem, in time, come to
+shoot out into a long, round and even stalk, which by cutting transversly,
+when dry, I manifestly found to be a stiff, hard, and hollow Cane, or Reed,
+without any kind of knot, or stop, from its bottom, where the leaves
+encompass'd it, to the top, on which there grows a large seed case, A,
+cover'd with a thin, and more whitish skin, B, terminated in a long thorny
+top, which at first covers all the Case, and by degrees, as that swells,
+the skin cleaves, and at length falls off, with its thorny top and all
+(which is a part of it) and leaves the seed Case to ripen, and by degrees,
+to shatter out its seed at a place underneath this cap, B, which before the
+seed is ripe, appears like a flat barr'd button, without any hole in the
+middle; but as it ripens, the button grows bigger, and a hole appears in
+the middle of it, E, out of which, in all probability, the seed falls: For
+as it ripens by a provision of Nature, that end of this Case turns downward
+after the same manner as the ears of Wheat and Barley usually do; and
+opening several of these dry red Cases, F, I found them to be quite hollow,
+without anything at all in them; whereas when I cut them asunder with a
+sharp Pen-knife when green, I found in the middle of this great Case,
+another smaller round Case, between which two, the _interstices_ were
+fill'd with multitudes of stringie _fibres_, which seem'd to suspend the
+lesser Case in the middle of the other, which (as farr as I was able to
+discern) seem'd full of exceeding small white seeds, much like the
+seed-bagg in the knop of a Carnation, after the flowers have been two or
+three days, or a week, fallen off; but this I could not so perfectly
+discern, and therefore cannot positively affirm it.
+
+After the seed was fallen away, I found both the Case, Stalk, and Plant,
+all grow red and wither, and from other parts of the root continually to
+spring new branches or slips, which by degrees increased, and grew as bigg
+as the former, seeded, ripen'd, shatter'd, and wither'd.
+
+I could not find that it observ'd any particular seasons for these several
+kinds of growth, but rather found it to be springing, mature, ripe, seedy,
+and wither'd at all times of the year; But I found it most to flourish and
+increase in warm and moist weather.
+
+It gathers its nourishments, for the most part, out of some _Lapidescent_,
+or other substance corrupted or chang'd from its former texture, or
+substantial form; for I have found it to grow on the rotten parts of Stone,
+of Bricks, of Wood, of Bones, of Leather, &c.
+
+It oft grows on the barks of several Trees, spreading it self, sometimes
+from the ground upwards, and sometimes from some chink or cleft of the bark
+of the Tree, which has some _putrify'd_ substance in it, but this seems of
+a distinct kind from that which I observ'd to grow on _putrify'd_ inanimate
+bodies, and rotten earth.
+
+There are also great varieties of other kinds of Mosses, which grow on
+Trees, and several other Plants, of which I shall here make no mention, nor
+of the Moss growing on the skull of a dead man, which much resembles that
+of Trees.
+
+Whether this Plant does sometimes originally spring or rise out of
+corruption, without any disseminated seed, I have not yet made trials
+enough to be very much, either positive or negative; for as it seems very
+hard to conceive how the seed should be generally dispers'd into all parts
+where there is a corruption begun, unless we may rationally suppose, that
+this seed being so exceeding small, and consequently exceeding light, is
+thereby taken up, and carried to and fro in the Air into every place, and
+by the falling drops of rain is wash'd down out of it, and so dispers'd
+into all places, and there onely takes root and propagates, where it finds
+a convenient soil or matrix for it to thrive in; so if we will have it to
+proceed from corruption, it is not less difficult to conceive,
+
+First, how the corruption of any Vegetable, much less of any Stone or
+Brick, should be the Parent of so curiously figur'd, and so perfect a Plant
+as this is. But here indeed, I cannot but add, that it seems rather to be a
+product of the Rain in those bodies where it is stay'd, then of the very
+bodies themselves, since I have found it growing on Marble, and Flint, but
+always the _Microscope_, if not the naked eye, would discover some little
+hole of Dirt in which it was rooted.
+
+Next, how the corruption of each of those exceedingly differing bodies
+should all conspire to the production of the same Plant, that is, that
+Stones, Bricks, Wood, or vegetable substances, and Bones, Leather, Horns,
+or animate substances, unless we may with some plausibleness say, that Air
+and Water are the coadjutors, or _menstruums_, all kinds of
+_putrifactions_, and that thereby the bodies (though whil'st they retain'd
+their substantial forms, were of exceeding differing natures, yet) since
+they are dissolv'd and mixt into another, they may be very _Homogeneous_,
+they being almost resolv'd again into Air, Water, and Earth; retaining,
+perhaps, one part of their vegetative faculty yet entire, which meeting
+with congruous assistants, such as the heat of the Air, and the fluidity of
+the Water, and such like coadjutors and conveniences, acquires a certain
+vegetation for a time, wholly differing perhaps from that kind of
+vegetation it had before.
+
+To explain my meaning a little better by a gross Similitude:
+
+Suppose a curious piece of Clock-work, that had had several motions and
+contrivances in it, which, when in order, would all have mov'd in their
+design'd methods and Periods. We will further suppose, by some means, that
+this Clock comes to be broken, brused, or otherwise disordered, so that
+several parts of it being dislocated, are impeded, and so stand still, and
+not onely hinder its own progressive motion, and produce not the effect
+which they were design'd for, but because the other parts also have a
+dependence upon them, put a stop to their motion likewise; and so the whole
+Instrument becomes unserviceable,, and not fit for any use. This Instrument
+afterwards, by some shaking and tumbling, and throwing up and down, comes
+to have several of its parts shaken out, and several of its curious
+motions, and contrivances, and particles all fallen asunder; here a Pin
+falls out, and there a Pillar, and here a Wheel, and there a Hammer, and a
+Spring, and the like, and among the rest, away falls those parts also which
+were brused and disorder'd, and had all this while impeded the motion of
+all the rest; hereupon several of those other motions that yet remain,
+whole springs were not quite run down, being now at liberty, begin each of
+them to move, thus or thus, but quite after another method then before,
+there being many regulating parts and the like, fallen away and lost. Upon
+this, the Owner, who chances to hear and observe some of these effects,
+being ignorant of the Watch-makers Art, wonders what is betid his Clock,
+and presently imagines that some Artist has been at work, and has set his
+Clock in order, and made a new kind of Instrument of it, but upon examining
+circumstances, he finds there was no such matter, but that the casual
+slipping out of a Pin had made several parts of his Clock fall to pieces,
+and that thereby the obstacle that all this while hindred his Clock,
+together with other usefull parts were fallen out, and so his Clock was set
+at liberty. And upon winding up those springs again when run down, he finds
+his Clock to go, but quite after another manner then it was wont
+heretofore.
+
+And thus may it be perhaps in the business of Moss, and Mould, and
+Mushroms, and several other spontaneous kinds of vegetations, which may be
+caus'd by a vegetative principle, which was a coadjutor to the life and
+growth of the greater Vegetable, and was by the destroying of the life of
+it stopt and impeded in performing its office; but afterwards, upon a
+further corruption of several parts that had all the while impeded it, the
+heat of the Sun winding up, as it were, the spring, sets it again into a
+vegetative motion, and this being single, and not at all regulated as it
+was before (when a part of that greater _machine_ the pristine vegetable)
+is mov'd after quite a differing manner, and produces effects very
+differing from those it did before.
+
+But this I propound onely as a conjecture, not that I am more enclin'd to
+this _Hypothesis_ then the seminal, which upon good reason I ghess to be
+Mechanical also, as I may elsewhere more fully shew: But because I may, by
+this, hint a possible way how this appearance may be solv'd; supposing we
+should be driven to confess from certain Experiments and Observations made,
+that such or such Vegetables were produc'd out of the corruption of
+another, without any concurrent seminal principle (as I have given some
+reason to suppose, in the description of a _Microscopical_ Mushrome)
+without derogating at all from the infinite wisdom of the Creator. For this
+accidental production, as I may call it, does manifest as much, if not very
+much more, of the excellency of his contrivance as any thing in the more
+perfect vegetative bodies of the world, even as the accidental motion of
+the _Automaton_ does make the owner see, that there was much more
+contrivance in it then at first he imagin'd. But of this I have added more
+in the description of Mould, and the Vegetables on Rose leaves, &c. those
+being much more likely to have their original from such a cause then this
+which I have here described, in the 13. _Scheme_, which indeed I cannot
+conceive otherwise of, then as of a most perfect Vegetable, wanting nothing
+of the perfections of the most conspicuous and vastest Vegetables of the
+world, and to be of a rank so high, as that it may very properly be
+reckon'd with the tall Cedar of _Lebanon_, as that Kingly Botanist has
+done.
+
+We know there may be as much curiosity of contrivance, and excellency of
+form in a very small Pocket-clock, that takes not up an Inch square of
+room, as there may be in a Church-clock that fills a whole room; And I know
+not whether all the contrivances and _Mechanisms_ requisite to a perfect
+Vegetable, may not be crowded into an exceedingly less room then this of
+Moss, as I have heard of a striking Watch so small, that it serv'd for a
+Pendant in a Ladies ear; and I have already given you the description of a
+Plant growing on Rose leaves, that is abundantly smaller then Moss;
+insomuch, that neer 1000. of them would hardly make the bigness of one
+single Plant of Moss. And by comparing the bulk of Moss, with the bulk of
+the biggest kind of Vegetable we meet with in Story (of which kind we find
+in some hotter climates, as _Guine_, and _Brasile_, the stock or body of
+some Trees to be twenty foot in Diameter, whereas the body or stem of Moss,
+for the most part, is not above one sixtieth part of an Inch) we shall find
+that the bulk of the one will exceed the bulk of the other, no less then
+2985984 Millions, or 2985984000000, and supposing the production on a Rose
+leaf to be a Plant, we shall have of those _Indian_ Plants to exceed a
+production of the same Vegetable kingdom no less then 1000 times the former
+number; so prodigiously various are the works of the Creator, and so
+All-sufficient is he to perform what to man would seem unpossible, they
+being both alike easie to him, even as one day, and a thousand years are to
+him as one and the same time.
+
+I have taken notice of such an infinite variety of those smaller kinds of
+vegetations, that should I have described every one of them, they would
+almost have fill'd a Volume, and prov'd bigg enough to have made a new
+Herbal, such multitudes are there to be found in moist hot weather,
+especially in the Summer time, on all kind of putrifying substances, which,
+whether they do more properly belong to the _Classis_ of _Mushrooms_, or
+_Moulds_, or _Mosses_, I shall not now dispute, there being some that seem
+more properly of one kind, others of another, their colours and magnitudes
+being as much differing as their Figures and substances.
+
+Nay, I have observ'd, that putting fair Water (whether Rain-water or
+Pump-water, or _May-dew_ or Snow-water, it was almost all one) I have often
+observ'd, I say, that this Water would, with a little standing, tarnish and
+cover all about the sides of the Glass that lay under water, with a lovely
+green; but though I have often endeavour'd to discover with my _Microscope_
+whether this green were like Moss, or long striped Sea-weed, or any other
+peculiar form, yet so ill and imperfect are our _Microscopes_, that I could
+not certainly discriminate any.
+
+Growing Trees also, and any kinds of Woods, Stones, Bones, &c. that have
+been long expos'd to the Air and Rain, will be all over cover'd with a
+greenish scurff, which will very much foul and green any kind of cloaths
+that are rubb'd against it; viewing this, I could not certainly perceive in
+many parts of it any determinate form, though in many I could perceive a
+Bed as 'twere of young Moss, but in other parts it look'd almost like green
+bushes, and very confus'd, but always of what ever irregular Figures the
+parts appear'd of, they were always green, and seem'd to be either some
+Vegetable, or to have some vegetating principle.
+
+       *       *       *       *       *
+
+
+Observ. XXII. _Of common _Sponges_, and several other _Spongie_ fibrous
+bodies._
+
+A Sponge is commonly reckon'd among the _Zoophyts_, or Plant Animals; and
+the _texture_ of it, which the _Microscope_ discovers, seems to confirm it;
+for it is of a form whereof I never observ'd any other Vegetable, and
+indeed, it seems impossible that any should be of it, for it consists of an
+infinite number of small short _fibres_, or nervous parts, much of the same
+bigness, curiously jointed or contex'd together in the form of a Net, as is
+more plainly manifest by the little Draught which I have added, in the
+third _Figure_ of the IX. _Scheme_, of a piece of it, which you may
+perceive represents a confus'd heap of the fibrous parts curiously jointed
+and implicated. The joints are, for the most part, where three _fibres_
+onely meet, for I have very seldom met with any that had four.
+
+At these joints there is no one of the three that seems to be the stock
+whereon the other grow, but each of the _fibres_ are, for the most part, of
+an equal bigness, and seem each of them to have an equal share in the
+joint; the _fibres_ are all of them much about the same bigness, not
+smaller towards the top of the Sponge, and bigger neerer the bottom or
+root, as is usuall in Plants, the length of each between the joints, is
+very irregular and different; the distance between some two joints, being
+ten or twelve times more then between some others.
+
+Nor are the joints regular, and of an _equitriagonal Figure_, but, for the
+most part, the three _fibres_ so meet, that they compose three angles very
+differing all of them from one another.
+
+The meshes likewise, and holes of this reticulated body, are not less
+various and irregular: some _bilateral_, others _trilateral_, and
+_quadrilateral_ Figures; nay, I have observ'd some meshes to have 5, 6, 7,
+8, or 9. sides, and some to have onely one, so exceeding various is the
+_Lusus Naturae_ in this body.
+
+As to the outward appearance of this Vegetative body, they are so usuall
+everywhere, that I need not describe them, consisting of a soft and porous
+substance, representing a Lock, sometimes a fleece of Wooll; but it has
+besides these small _microscopical_ pores which lie between the _fibres_, a
+multitude of round pores or holes, which, from the top of it, pierce into
+the body, and sometimes go quite through to the bottom.
+
+I have observ'd many of these Sponges, to have included likewise in the
+midst of their fibrous contextures, pretty large friable stones, which must
+either have been inclos'd whil'st this Vegetable was in formation, or
+generated in those places after it was perfectly shap'd. The later of which
+seems the more improbable, because I did not find that any of these stony
+substances were perforated with the _fibres_ of the Sponge.
+
+I have never seen nor been enform'd of the true manner of the growing of
+Sponges on the Rock; whether they are found to increase from little to
+great, like Vegetables, that is, part after part, or like Animals, all
+parts equally growing together; or whether they be _matrices_ or feed-baggs
+of any kind of Fishes, or some kind of watry Insect; or whether they are at
+any times more soft and tender, or of another nature and texture, which
+things, if I knew how, I should much desire to be informed of: but from a
+cursory view that I at first made with my _Microscope_, and some other
+trials, I supposed it to be some Animal substance cast out, and fastned
+upon the Rocks in the form of a froth, or _congeries_ of bubbles, like that
+which I have often observ'd on Rosemary, and other Plants (wherein is
+included a little Insect) that all the little films which divide these
+bubbles one from another, did presently, almost after the substance began
+to grow a little harder, break, and leave onely the thread behind, which
+might be, as 'twere, the angle or thread between the bubbles, that the
+great holes or pores observable in these Sponges were made by the eruption
+of the included _Heterogeneous_ substance (whether air, or some other body,
+for many other fluid bodies will do the same thing) which breaking out of
+the lesser, were collected into very large bubbles, and so might make their
+way out of the Sponge, and in their passage might leave a round cavity; and
+if it were large, might carry up with it the adjacent bubbles, which may be
+perceiv'd at the outside of the Sponge, if it be first throughly wetted,
+and sufferr'd to plump itself into its natural form, or be then wrung dry,
+and suffer'd to expand it self again, which it will freely do whil'st
+moist: for when it has thus plump'd it self into its natural shape and
+dimensions, 'tis obvious enough that the mouths of the larger holes have a
+kind of lip or rising round about them, but the other smaller pores have
+little or none. It may further be found, that each of these great pores has
+many other small pores below, that are united unto it, and help to
+constitute it, almost like so many rivulets or small streams that
+contribute to the maintenance of a large River. Nor from this _Hypothesis_
+would it have been difficult to explicate, how those little branches of
+_Coral_, smal _Stones_, _shells_, and the like, come to be included by
+these frothy bodies: But this inded was but a conjecture; and upon a more
+accurate enquiry into the form of it with the _Microscope_, it seems not to
+be the true origine of them; for whereas Sponges have onely three arms
+which join together at each knot, if they had been generated from bubbles
+they must have had four.
+
+But that they are Animal Substances, the _Chymical_ examination of them
+seems to manifest, they affording a volatil Salt and spirit, like
+_Harts-Horn_, as does also their great strength and toughness, and their
+smell when burn'd in the Fire or a Candle, which has a kind of fleshy sent,
+not much unlike to hair. And having since examin'd several Authors
+concerning them, among others; I find this account given by _Bellonius_, in
+the XI. _Chap._ of his 2d Book, _De Aquatilibus_. _Spongiae recentes_, says
+he, _a siccis longe diversae, scopulis aquae marinae ad duos vel tres
+cubitos, nonnunquam quatuor tantum digitos immersis, ut fungi arboribus
+adhaerent, sordido quodam succo aut mucosa potius sanie refertae, usque
+adeo foetida, ut vel eminus nauseam excitet, continetur autem iis cavernis,
+quas inanes in siccis & lotis Spongiis cernimus: Putris pulmonis modo
+nigrae conspiciuntur, verum quae in sublimi aquae nascuntur multo magis
+opaca nigredine suffusae sunt. Vivere quidem Spongias adhaerendo
+_Aristoteles_ censet: absolute vero minime: sensumque aliquem habere, vel
+eo argumento (inquit) credantur, quod difficillime abstrahantur, nisi
+clanculum agatur: Atq; ad avulsoris accessum ita contrahantur, ut eas
+evellere difficile sit, quod idem etiam faciunt quoties flatus
+tempestatesque urgent. Puto autem illis succum sordidum quem supra diximus
+carnis loco a natura attributum fuisse: atque meatibus latioribus tanquam
+intestinis aut interaneis uti. Caeterum pars ea quae Spongiae cautibus
+adhaerent est tanquam folii petiolus, a quo veluti collum quoddam gracile
+incipit: quod deinde in latitudinem diffusum capitis globum facit.
+Recentibus nihil est fistulosum, haesitantque tanquam radicibus. Superne
+omnes propemodum meatus concreti latent: inferne vero quaterni aut quini
+patent, per quos eas sugere existimamus_. From which Description, they
+seem to be a kind of Plant-Animal that adheres to a Rock, and these small
+_fibres_ or threads which we have described, seem to have been the Vessels
+which ('tis very probable) were very much bigger whil'st the _Interstitia_
+were fill'd (as he affirms) with a mucous, pulpy or fleshy substance; but
+upon the drying were shrunk into the bigness they now appear.
+
+The texture of it is such, that I have not yet met with any other body in
+the world that has the like, but onely one of a larger sort of Sponge
+(which is preserv'd in the _Museum Harveanum_ belonging to the most
+Illustrious and most learned Society of the _Physicians_ of _London_) which
+is of a horney, or rather of a _petrify'd_ substance. And of this indeed,
+the texture and make is exactly the same with common Sponges, but onely
+that both the holes and the _fibres_, or texture of it is exceedingly much
+bigger, for some of the holes were above an Inch and half over, and the
+_fibres_ and _texture_ of it was bigg enough to be distinguished easily
+with ones eye, but conspicuously with an ordinary single _Microscope_. And
+these indeed, seem'd to have been the habitation of some Animal; and
+examining _Aristotle_, I find a very consonant account hereunto, namely,
+that he had known a certain little Animal, call'd _Pinnothera_, like a
+Spider, to be bred in those caverns of a Sponge, from within which, by
+opening and closing those holes, he insnares and catches the little Fishes;
+and in another place he says, That 'tis very confidently reported, that
+there are certain Moths or Worms that reside in the cavities of a Sponge,
+and are there nourished: Notwithstanding all which Histories, I think it
+well worth the enquiring into the History and nature of a Sponge, it
+seeming to promise some information of the Vessels in Animal substances,
+which (by reason of the solidity of the interserted flesh that is not
+easily remov'd, without destroying also those interspers'd Vessels) are
+hitherto undiscover'd; whereas here in a Sponge, the _Parenchyma_, it
+seems, is but a kind of mucous gelly, which is very easily and cleerly
+wash'd away.
+
+The reason that makes me imagine, that there may probably be some such
+texture in Animal substances, is, that examining the texture of the
+filaments of tann'd Leather, I find it to be much of the same nature and
+strength of a Sponge; and with my _Microscope_, I have observ'd many such
+joints and knobs, as I have described in Sponges, the _fibres_ also in the
+hollow of several sorts of Bones, after the Marrow has been remov'd, I have
+found somewhat to resemble this texture, though, I confess, I never yet
+found any texture exactly the same, nor any for curiosity comparable to it.
+
+The filaments of it are much smaller then those of Silk, and through the
+_Microscope_ appear very neer as transparent, nay, some parts of them I
+have observ'd much more.
+
+Having examin'd also several kinds of Mushroms, I finde their texture to be
+somewhat of this kind, that is, to consist of an infinite company of small
+filaments, every way contex'd and woven together, so as to make a kind of
+cloth, and more particularly, examining a piece of Touch-wood (which is a
+kind _Jews-ear_, or Mushrom, growing here in _England_ also, on several
+sorts of Trees, such as Elders, Maples, Willows, &c. and is commonly call'd
+by the name of _Spunk_; but that we meet with to be sold in Shops, is
+brought from beyond Seas) I found it to be made of an exceeding delicate
+texture: For the substance of it feels, and looks to the naked eye, and may
+be stretch'd any way, exactly like a very fine piece of _Chamois_ Leather,
+or wash'd Leather, but it is of somewhat a browner hew, and nothing neer so
+strong; but examining it with my _Microscope_, I found it of somewhat
+another make then any kind of Leather; for whereas both _Chamois_, and all
+other kinds of Leather I have yet view'd, consist of an infinite company of
+filaments, somewhat like bushes interwoven one within another, that is, of
+bigger parts or stems, as it were, and smaller branchings that grow out of
+them; or like a heap of Ropes ends, where each of the larger Ropes by
+degrees seem to split or untwist, into many smaller Cords, and each of
+those Cords into smaller Lines, and those Lines into Threads, &c. and these
+strangely intangled, or interwoven one within another: The texture of this
+Touch-wood seems more like that of a Lock or a Fleece of Wool, for it
+consists of an infinite number of small filaments, all of them, as farr as
+I could perceive, of the same bigness like those of a Sponge, but that the
+_filaments_ of this were not a twentieth part of the bigness of those of a
+Sponge; and I could not so plainly perceive their joints, or their manner
+of interweaving, though, as farr as I was able to discern with that
+_Microscope_ I had, I suppose it to have some kind of resemblance, but the
+joints are nothing neer so thick, nor without much trouble visible.
+
+The filaments I could plainly enough perceive to be even, round,
+cylindrical, transparent bodies, and to cross each other every way, that
+is, there were not more seem'd to lie _horizontally_ then _perpendicularly_
+and thwartway, so that it is somewhat difficult to conceive how they
+should grow in that manner. By tearing off a small piece of it, and looking
+on the ragged edge, I could among several of those _fibres_ perceive small
+joints, that is, one of those hairs split into two, each of the same
+bigness with the other out of which they seem'd to grow, but having not
+lately had an opportunity of examining their manner of growth, I cannot
+positively affirm any thing of them.
+
+But to proceed, The swelling of Sponges upon wetting, and the rising of the
+Water in it above the surface of the Water that it touches, are both from
+the same cause, of which an account is already given in the sixth
+Observation.
+
+The substance of them indeed, has so many excellent properties, scarce to
+be met with in any other body in the world, that I have often wondered that
+so little use is made of it, and those onely vile and sordid; certainly, if
+it were well consider'd, it would afford much greater conveniencies.
+
+That use which the Divers are said to make of it, seems, if true, very
+strange, but having made trial of it my self, by dipping a small piece of
+it in very good Sallet-oyl, and putting it in my mouth, and then keeping my
+mouth and nose under water, I could not find any such thing; for I was as
+soon out of breath as if I had had no Sponge, nor could I fetch my breath
+without taking in water at my mouth; but I am very apt to think, that were
+there a contrivance whereby the expir'd air might be forc'd to pass through
+a wet or oyly Sponge before it were again inspir'd, it might much cleanse,
+and strain away from the Air divers fuliginous and other noisome steams,
+and the dipping of it in certain liquors might, perhaps, so renew that
+property in the Air which it loses in the Lungs, by being breath'd, that
+one square foot of Air might last a man for respiration much longer,
+perhaps, then ten will now serve him of common Air.
+
+       *       *       *       *       *
+
+
+Observ. XXIII. _Of the curious texture of _Sea-weeds_._
+
+For curiosity and beauty, I have not among all the Plants or Vegetables I
+have yet observ'd, seen any one comparable to this Sea-weed I have here
+describ'd, of which I am able to say very little more then what is
+represented by the second _Figure_ of the ninth _Scheme_: Namely, that it
+is a Plant which grows upon the Rocks under the water, and increases and
+spreads it self into a great tuft, which is not onely handsomely branch'd
+into several leaves, but the whole surface of the Plant is cover'd over
+with a most curious kind of carv'd work, which consists of a texture much
+resembling a Honey-comb; for the whole surface on both sides is cover'd
+over with a multitude of very small holes, being no bigger then so many
+holes made with the point of a small Pinn, and rang'd in the neatest and
+most delicate order imaginable, they being plac'd in the manner of a
+_Quincunx_, or very much like the rows of the eyes of a Fly, the rows or
+orders being very regular, which way soever they are observ'd: what the
+texture was, as it appear'd through a pretty bigg Magnifying _Microscope_,
+I have here adjoin'd in the first _Figure_ of the 14. _Scheme._ which round
+Area ABCD represents a part of the surface about one eighth part of an Inch
+in Diameter: Those little holes, which to the eye look'd round, like so
+many little spots, here appear'd very regularly shap'd holes, representing
+almost the shape of the sole of a round toed shoe, the hinder part of
+which, is, as it were, trod on or cover'd by the toe of that next below it;
+these holes seem'd wall'd about with a very thin and transparent substance,
+looking of a pale straw-colour; from the edge of which, against the middle
+of each hole, were sprouted out four small transparent straw-colour'd
+Thorns, which seem'd to protect and cover those cavities, from either side
+two; neer the root of this Plant, were sprouted out several small branches
+of a kind of bastard _Coralline_, curiously branch'd, though small.
+
+And to confirm this, having lately the opportunity of viewing the large
+Plant (if I may so call it) of a Sponge _petrify'd>_, of which I made
+mention in the last Observation, I found, that each of the Branches or
+Figures of it, did, by the range of its pores, exhibit just such a texture,
+the rows of pores crossing one another, much after the manner as the rows
+of eyes do which are describ'd in the 26. _Scheme_: _Coralline_ also, and
+several sorts of white _Coral_, I have with a _Microscope_ observ'd very
+curiously shap'd. And I doubt not, but that he that shall observe these
+several kinds of Plants that grow upon Rocks, which the Sea sometimes
+overflows, and those heaps of others which are vomited out of it upon the
+shore, may find multitudes of little Plants, and other bodies, which like
+this will afford very beautifull objects for the _Microscope_; and this
+_Specimen_ here is adjoin'd onely to excite their curiosities who have
+opportunity of observing to examine and collect what they find worthy their
+notice; for the Sea, among terrestrial bodies, is also a _prolifick_
+mother, and affords as many Instances of _spontaneous_ generations as
+either the Air or Earth.
+
+       *       *       *       *       *
+
+
+Observ. XXIV. _Of the surfaces of _Rosemary_, and other leaves._
+
+This which is delineated within the circle of the second _Figure_ of the
+14. _Scheme_, is a small part of the back or under side of a leaf of
+Rosemary, which I did not therefore make choice of because it had any thing
+peculiar which was not observable with a _Microscope_ in several other
+Plants, but because it exhibits at one view,
+
+First, a smooth and shining surface, namely, AB, which is a part of the
+upper side of the leaf, that by a kind of hem or doubling of the leaf
+appears on this side. There are multitudes of leaves, which surfaces are
+like this smooth, and as it were quilted, which look like a curious quilted
+bagg of green Silk, or like a Bladder, or some such pliable transparent
+substance, full stuffed out with a green juice or liquor; the surface of
+Rue, or Herbgrass, is polish'd, and all over indented, or pitted, like the
+Silk-worm's Egg, which I shall anon describe; the smooth surfaces of other
+Plants are otherwise quilted, Nature in this, as it were, expressing her
+Needle-work, or imbroidery.
+
+Next a downy or bushy surface, such as is all the under side almost,
+appearing through the _Microscope_ much like a thicket of bushes, and with
+this kind of Down or Hair the leaves and stalks of multitudes of Vegetables
+are covered; and there seems to be as great a variety in the shape, bulk,
+and manner of the growing of these secundary Plants, as I may call them
+(they being, as it were, a Plant growing out of a Plant, or somewhat like
+the hairs of Animals) as there is to be found amongst small shrubs that
+compose bushes; but for the most part, they consist of small transparent
+parts, some of which grow in the shape of small Needles or Bodkins, as on
+the Thistle, Cowag-ecod and Nettle; others in the form of Cat's claws, as
+in Cliders, the beards of Barley, the edges of several sorts of Grass and
+Reeds, &c. in other, as Coltsfoot, Rose-campion, Aps, Poplar, Willow, and
+almost all other downy Plants, they grow in the form of bushes very much
+diversify'd in each particular Plant, That which I have before in the 19.
+Observation noted on Rose-leaves, is of a quite differing kind, and seems
+indeed a real Vegetable, distinct from the leaf.
+
+Thirdly, among these small bushes are observable an infinite company of
+small round Balls, exactly Globular, and very much resembling Pearls,
+namely, CCCC, of these there maybe multitudes observ'd in Sage, and several
+other Plants, which I suppose was the reason why _Athanasius Kircher_
+supposed them to be all cover'd with Spiders Eggs, or young Spiders, which
+indeed is nothing else but some kind of gummous exsudation, which is always
+much of the same bigness. At first sight of these, I confess, I imagin'd
+that they might have been some kind of _matrices_, or nourishing
+receptacles for some small Insect, just as I have found Oak-apples, and
+multitudes of such other large excrescencies on the leaves and other parts
+of Trees and shrubs to be for Flyes, and divers other Insects, but
+observing them to be there all the year, and scarce at all to change their
+magnitude, that conjecture seem'd not so probable. But what ever be the use
+of it, it affords a very pleasant object through the _Microscope_, and may,
+perhaps, upon further examination, prove very luciferous.
+
+       *       *       *       *       *
+
+
+Observ. XXV. _Of the stinging points and juice of _Nettles_, and some other
+venomous Plants._
+
+A Nettle is a Plant so well known to every one, as to what the appearance
+of it is to the naked eye, that it needs no description; and there are very
+few that have not felt as well as seen it; and therefore it will be no news
+to tell that a gentle and slight touch of the skin by a Nettle, does
+oftentime, not onely create very sensible and acute pain, much like that of
+a burn or scald, but often also very angry and hard swellings and
+inflamations of the parts, such as will presently rise, and continue swoln
+divers hours. These observations, I say, are common enough; but how the
+pain is so suddenly created, and by what means continued, augmented for a
+time, and afterwards diminish'd, and at length quite exstinguish'd, has
+not, that I know, been explain'd by any.
+
+And here we must have recourse to our _Microscope_, and that will, if
+almost any part of the Plant be looked on, shew us the whole surface of it
+very thick set with turn-Pikes, or sharp Needles, of the shape of those
+represented in the 15. _Scheme_ and first _Figure_ by AB, which are visible
+also to the naked eye; each of which consists of two parts very distinct
+for shape, and differing also in quality from one another. For the part A,
+is shaped very much like a round Bodkin, from B tapering till it end in a
+very sharp point; it is of substance very hard and stiff, exceedingly
+transparent and cleer, and, as I by many trials certainly found, is hollow
+from top to bottom.
+
+This I found by this Experiment, I had a very convenient _Microscope_ with
+a single Glass which drew about half an Inch, this I had fastned into a
+little frame, almost like a pair of Spectacles, which I placed before mine
+eyes, and so holding the leaf of a Nettle at a convenient distance from my
+eye, I did first, with the thrusting of several of these bristles into my
+skin, perceive that presently after I had thrust them in I felt the burning
+pain begin; next I observ'd in divers of them, that upon thrusting my
+finger against their tops, the Bodkin (if I may so call it) did not in the
+least bend, but I could perceive moving up and down within it a certain
+liquor, which upon thrusting the Bodkin against its basis, or bagg B, I
+could perceive to rise towards the top, and upon taking away my hand, I
+could see it again subside, and shrink into the bagg; this I did very
+often, and saw this _Phaenomenon_ as plain as I could ever see a parcel of
+water ascend and descend in a pipe of Glass. But the basis underneath these
+Bodkins on which they were fast, were made of a more pliable substance, and
+looked almost like a little bagg of green Leather, or rather resembled the
+shape and surface of a wilde Cucumber, or _cucumeris asinini_, and I could
+plainly perceive them to be certain little baggs, bladders, or receptacles
+full of water, or as I ghess, the liquor of the Plant, which was poisonous,
+and those small Bodkins were but the Syringe-pipes, or Glyster-pipes, which
+first made way into the skin, and then served to convey that poisonous
+juice, upon the pressing of those little baggs, into the interior and
+sensible parts of the skin, which being so discharg'd, does corrode, or, as
+it were, burn that part of the skin it touches; and this pain will
+sometimes last very long, according as the impression is made deeper or
+stronger.
+
+The other parts of the leaf or surface of the Nettle, have very little
+considerable, but what is common to most of these kinds of Plants, as the
+ruggedness or indenting, and hairiness, and other roughnesses of the
+surface or out-side of the Plant, of which I may say more in another place.
+As I shall likewise of certain little pretty cleer Balls or Apples which I
+have observed to stick to the sides of these leaves, both on the upper and
+under side, very much like the small Apples which I have often observ'd to
+grow on the leaves of an Oak call'd _Oak-apples_ which are nothing but the
+_Matrices_ of an Infect, as I elsewhere shew.
+
+The chief thing therefore is, how this Plant comes, by so slight a touch,
+to create so great a pain; and the reason of this seems to be nothing else,
+but the corrosive penetrant liquor contain'd in the small baggs or
+bladders, upon which grow out those sharp Syringe-pipes, as I before noted;
+and very consonant to this, is the reason of the pain created by the sting
+of a Bee, Wasp, &c. as I elsewhere shew: For by the Dart, which is likewise
+a pipe, is made a deep passage into the skin, and then by the anger of the
+Fly, is his gally poisonous liquor injected; which being admitted among the
+sensible parts, and so mix'd with the humours or _stagnating_ juices of
+that part, does create an Ebullition perhaps, or _effervescens_, as is
+usually observ'd in the mingling of two differing _Chymical saline_
+liquors, by which means the parts become swell'd, hard, and very painfull;
+for thereby the nervous and sensible parts are not onely stretch'd and
+strain'd beyond their natural _tone_, but are also prick'd, perhaps, or
+corroded by the pungent and incongruous parts of the intruded liquor.
+
+And this seems to be the reason, why _Aqua fortis_, and other _saline_
+liquors, if they come to touch the sensitive parts, as in a cut of the
+skin, or the like, do so violently and intollerably _excruciate_ and
+torment the Patient. And 'tis not unlikely, but the Inventors of that
+Diabolical practice of poisoning the points of Arrows and Ponyards, might
+receive their first hint from some such Instance in natural contrivances,
+as this of the Nettle: for the ground why such poison'd weapons kill so
+infallibly as they do, seems no other then this of our Nettle's stinging;
+for the Ponyard or Dart makes a passage or entrance into the sensitive or
+vital parts of the body, whereby the contagious substance comes to be
+dissolv'd by, and mix'd with the fluid parts or humours of the body, and by
+that means spreads it self by degrees into the whole liquid part of the
+body, in the same manner, as a few grains of Salt, put into a great
+quantity of Water, will by degrees diffuse it self over the whole.
+
+And this I take to be the reason of killing of Toads, Frogs, Effs, and
+several Fishes, by strewing Salt on their backs (which Experiment was shewn
+to the _Royal Society_ by a very ingenious Gentleman, and a worthy Member
+of it) for those creatures having always a continual exsudation, as it
+were, of slimy and watry parts, sweating out of the pores of their skin,
+the _saline_ particles, by that means obtain a _vehicle_, which conveys
+them into the internal and vital parts of the body.
+
+This seems also to be the reason why bathing in Mineral waters are such
+soveraign remedies for multitudes of distempers, especially chronical; for
+the liquid & warm _vehicles_ of the Mineral particles, which are known to
+be in very considerable quantities in those healing baths, by the body's
+long stay in them, do by degrees steep and insinuate themselves into the
+pores and parts of the skin, and thereby those Mineral particles have their
+ways and passages open'd to penetrate into the inner parts, and mingle
+themselves with the _stagnant_ juices of the several parts; besides, many
+of those offensive parts which were united with those _stagnant_ juices,
+and which were contrary to the natural constitution of the parts, and so
+become irksome and painfull to the body, but could not be discharged,
+because Nature had made no provision for such accidental mischiefs, are, by
+means of this soaking, and filling the pores of the skin with a liquor,
+afforded a passage through that liquor that fills the pores into the
+ambient fluid, and thereby the body comes to be discharged.
+
+So that 'tis very evident, there may be a good as well as an evil
+application of this Principle. And the ingenious Invention of that
+Excellent person, Doctor _Wren_ of injecting liquors into the veins of an
+Animal, seems to be reducible to this head: I cannot stay, nor is this a
+fit place, to mention the several Experiments made of this kind by the most
+incomparable Mr. _Boyle_, the multitudes made by the lately mention'd
+_Physician_ Doctor _Clark_, the History whereof, as he has been pleas'd to
+communicate to the _Royal Society_, so he may perhaps be prevail'd with to
+make publique himself: But I shall rather hint, that certainly, if this
+Principle were well consider'd, there might, besides the further improving
+of Bathing and Syringing into the veins, be thought on several ways,
+whereby several obstinate distempers of a humane body, such as the Gout,
+Dropsie, Stone, &c. might be master'd, and expell'd; and good men might
+make as good a use of it, as evil men have made a perverse and Diabolical.
+
+And that the filling of the pores of the skin with some fluid _vehicle_, is
+of no small efficacy towards the preparing a passage for several kinds of
+penetrant juices, and other dissoluble bodies, to insinuate themselves
+within the skin, and into the sensitive parts of the body, may be, I think,
+prov'd by an Instance given us by _Bellonius_, in the 26. _Chapter_ of the
+second Book of his _Observations_, which containing a very remarkable Story
+I have here transcrib'd: _Cum Chamaeleonis nigri radices_ (says he) _apud
+Pagum quendam Livadochorio nuncupatum erui curaremus, plurimi Graeci &
+Turcae spectatum venerunt quid erueremus, eas vero frustulatim secabamus, &
+filo trajiciebamus ut facilius exsiccari possent. Turcae in eo negotio
+occupatos nos videntes, similiter eas radices tractare & secare voluerunt:
+at cum summus esset aestus, & omnes sudore maderent, quicunque eam radicem
+manibus tractaverant sudoremque absterserant, aut faciem digitis
+scalpserant, tantam pruriginem iis locis quos attigerant postea senserunt,
+ut aduri viderentur. Chamaeleonis enim nigri radix ea virtute pollet, ut
+cuti applicata ipsam adeo inflammet, ut nec squillae, nec urticae ullae
+centesima parte ita adurent: At prurigo non adeo celeriter sese prodit.
+Post unam aut alteram porro horam, singuli variis faciei locis cutem adeo
+inflammatam habere caepimus ut tota sanguinea videretur, atque quo magis
+eam confricabamus, tanto magis excitabatur prurigo. Fonti assidebamus sub
+platano, atque initio pro ludicro habebamus & ridebamus: at tandem illi
+plurimum indignati sunt, & nisi asseverassemus nunquam expertos tali
+virtute eam plantam pollere, haud dubie male nos multassent, Attamen nostra
+excusatio fuit ab illis facilitus accepta, cum eodem incommodo nos affectos
+conspicerent. Mirum sane quod in tantillo radice tam ingentem efficaciam
+nostro malo experti sumus._
+
+By which observation of his, it seems manifest, that their being all
+cover'd with sweat who gather'd and cut this root of the black _Chameleon_
+Thistle, was the great reason why they suffer'd that inconvenience, for it
+seems the like circumstance had not been before that noted, nor do I find
+any mention of such a property belonging to this Vegetable in any of the
+Herbals I have at present by me.
+
+I could give very many Observations which I have made of this kind, whereby
+I have found that the best way to get a body to be insinuated into the
+substance or insensible pores of another, is first, to find a fluid
+_vehicle_ that has some congruity, both to the body to be insinuated, and
+to the body into whose pores you would have the other convey'd. And in this
+Principle lies the great mystery of staining several sorts of bodies, as
+Marble, Woods, Bones, &c. and of Dying Silks, Cloaths, Wools, Feathers, &c.
+But these being digressions, I shall proceed to:
+
+       *       *       *       *       *
+
+
+Observ. XXVI. _Of _Cowage_, and the itching operation of some bodies._
+
+There is a certain Down of a Plant, brought from the _East-Indies_, call'd
+commonly, though very improperly, _Cow-itch_, the reason of which mistake
+is manifest enough from the description of it, which Mr. _Parkinson_ sets
+down in his _Herbal_, Tribe XI. Chap. 2. _Phasiolus siliqua hirsuta; The
+hairy Kidney-bean, called in _Zurratte_ where it grows, Couhage: We have
+had_ (says he) _another of this kind brought us out of the _East-Indies_,
+which being planted was in shew like the former, but came not to
+perfection, the unkindly season not suffering it to shew the flower; but of
+the Cods that were brought, some were smaller, shorter, and rounder then
+the Garden kind; others much longer, and many growing together, as it were
+in clusters, and cover'd all over with a brown short hairiness, so fine,
+that if any of it be rubb'd, or fall on the back of ones hand, or other
+tender parts of the skin, it will cause a kind of itching, but not strong,
+nor long induring, but passing quickly away, without either danger or harm;
+the Beans were smaller then ordinary, and of a black shining colour._
+
+Having one of these Cods given me by a Sea-Captain, who had frequented
+those parts, I found it to be a small Cod, about three Inches long, much
+like a short Cod of _French Beans_, which had six Beans in it, the whole
+surface of it was cover'd over with a very thick and shining brown Down or
+Hair, which was very fine, and for its bigness stiff; taking some of this
+Down, and rubbing it on the back of my hand, I found very little or no
+trouble, only I was sensible that several of these little downy parts with
+rubbing did penetrate, and were sunk, or stuck pretty deep into my skin.
+After I had thus rubb'd it for a pretty while, I felt very little or no
+pain, in so much that I doubted, whether it were the true Couhage; but
+whil'st I was considering; I found the Down begin to make my hand itch, and
+in some places to smart again, much like the stinging of a Flea or Gnat,
+and this continued a pretty while, so that by degrees I found my skin to be
+swell'd with little red pustules, and to look as if it had been itchie. But
+suffering it without rubbing or scratching, the itching tickling pain
+quickly grew languid, and within an hour I felt nothing at all, and the
+little _protuberancies_ were vanish'd.
+
+The cause of which odd _Phaenomenon_, I suppose to be much the same with
+that of the stinging of a Nettle, for by the _Microscope_, I discover'd
+this Down to consist of a multitude of small and slender conical bodies,
+much resembling Needles or Bodkins, such as are represented by AB. CD. EF.
+of the first Figure of the XVI. _Scheme_; that their ends AAA, were very
+sharp, and the substance of them stiff and hard, much like the substance of
+several kinds of Thorns and crooks growing on Trees. And though they
+appear'd very cleer and transparent, yet I could not perceive whether they
+were hollow or not, but to me they appear'd like solid transparent bodies,
+without any cavity in them; whether, though they might not be a kind of
+Cane, fill'd with some transparent liquor which was hardned (because the
+Cod which I had was very dry) I was not able to examine.
+
+Now, being such stiff, sharp bodies, it is easie to conceive, how with
+rubbing they might easily be thrust into the tender parts of the skin, and
+there, by reason of their exceeding fineness and driness, not create any
+considerable trouble or pain, till by remaining in those places moistned
+with the humours of the body, some caustick part sticking on them, or
+residing within them might be dissolv'd and mix'd with the ambient juices
+of that place, and thereby those _fibres_ and tender parts adjoyning become
+affected, and as it were corroded by it; whence, while that action lasts,
+the pains created are pretty sharp and pungent, though small, which is the
+essential property of an itching one.
+
+That the pain also caused by the stinging of a Flea, a Gnat, a Flie, a
+Wasp, and the like, proceeds much from the very same cause, I elsewhere in
+their proper places endeavour to manifest. The stinging also of shred
+Hors-hair, which in meriment is often strew'd between the sheets of a Bed,
+seems to proceed from the same cause.
+
+       *       *       *       *       *
+
+
+Observ. XXVII. _Of the _Beard_ of a wilde _Oat_, and the use that may be
+made of it for exhibiting always to the Eye the temperature of the Air, as
+to driness and moisture._
+
+This Beard of a wild _Oat_, is a body of a very curious structure, though
+to the naked Eye it appears very slight, and inconsiderable, it being only
+a small black or brown Beard or Bristle, which grows out of the side of the
+inner Husk that covers the Grain of a wild _Oat_; the whole length of it,
+when put in Water, so that it may extend it self to its full length, is not
+above an Inch and a half, and for the most part somewhat shorter, but when
+the Grain is ripe, and very dry, which is usualy in the Moneths of _July_,
+and _August_, this Beard is bent somewhat below the middle, namely, about
+2/5 from the bottom of it, almost to a right Angle, and the under part of
+it is wreath'd lik a With; the substance of it is very brittle when dry,
+and it will very easily be broken from the husk on which it grows.
+
+If you take one of these Grains, and wet the Beard in Water, you will
+presently see the small bended top to turn and move round, as if it were
+sensible; and by degrees, if it be continued wet enough, the joint or knee
+will streighten it self; and if it be suffer'd to dry again, it will by
+degrees move round another way, and at length bend again into its former
+posture.
+
+If it be view'd with an ordinary single _Microscope_, it will appear like a
+small wreath'd Sprig, with two clefts; and if wet as before, and then
+look'd on with this _Microscope_, it will appear to unwreath it self, and
+by degrees, to streighten its knee, and the two clefts will become
+streight, and almost on opposite sides of the small cylindrical body.
+
+If it be continued to be look'd on a little longer with a _Microscope_, it
+will within a little while begin to wreath it self again, and soon after
+return to its former posture, bending it self again neer the middle, into a
+kind of knee or angle.
+
+Several of those bodies I examin'd with larger _Microscopes_, and there
+found them much of the make of those two long wreath'd cylinders delineated
+in the second Figure of the 15. _Scheme_, which two cylinders represent the
+wreathed part broken into two pieces, whereof the end AB is to be suppos'd
+to have join'd to the end CD, so that EACF does represent the whole
+wreath'd part of the Beard, and EG a small piece of the upper part of the
+Beard which is beyond the knee, which as I had not room to insert, so was
+it not very considerable, either for its form, or any known property; but
+the under or wreathed part is notable for both: As to its form, it
+appear'd, if it were look'd on side-ways, almost like a Willow, or a small
+tapering rod of _Hazel_, the lower or bigger half of which onely, is
+twisted round several times, in some three, in others more, in others less,
+according to the bigness and maturity of the Grain on which it grew, and
+according to the driness and moisture of the ambient Air, as I shall shew
+more at large by and by.
+
+The whole outward Superficies of this Cylindrical body is curiously adorned
+or fluted with little channels, and interjacent ridges, or little
+_protuberances_ between them, which run the whole length of the Beard, and
+are streight where the Beard is not twisted, and wreath'd where it is, just
+after the same manner: each of those sides is beset pretty thick with small
+Brides or Thorns, somewhat in form resembling that of _Porcupines_ Quills,
+such as _aaaaa_ in the Figure; all whose points are directed like so many
+Turn-pikes towards the small end or top of the Beard, which is the reason,
+why, if you endeavour to draw the Beard between your fingers the contrary
+way, you will find it to stick, and grate, as it were, against the skin.
+
+The proportion of these small conical bodies _aaaaa_ to that whereon they
+grow, the Figure will sufficiently shew, as also their manner of growing,
+their thickness, and neerness to each other, as, that towards the root or
+bottom of the Beard, they are more thin, and much shorter, insomuch that
+there is usually left between the top of the one, and the bottom of that
+next above it, more then the length of one of them, and that towards the
+top of the Beard they grow more thick and close (though there be fewer
+ridges) so that the root, and almost half the upper are hid by the tops of
+those next below them.
+
+I could not perceive any _transverse_ pores, unless the whole wreath'd part
+were separated and cleft, in those little channels, by the wreathing into
+so many little strings as there were ridges, which was very difficult to
+determine; but there were in the wreathed part two very conspicuous
+channels or clefts, which were continued from the bottom F to the elbow bow
+EH or all along the part which was wreath'd, which seem'd to divide the
+wreath'd Cylinder into two parts, a bigger and a less; the bigger was that
+which was at the _convex_ side of the knee, namely, on the side A, and was
+wreath'd by OOOOO; this, as it seem'd the broader, so did it also the
+longer, the other PPPPP, which was usually purs'd or wrinckled in the
+bending of the knee, as about E, seem'd both the shorter and narrower, so
+that at first I thought the wreathing and unwreathing of the Beard might
+have been caus'd by the shrinking or swelling of that part; but upon
+further examination, I sound that the clefts, KK, LL, were stuft up with a
+kind of Spongie substance, which, for the most part, was very conspicuous
+neer the knee, as in the cleft KK, when the Beard was dry; upon the
+discovery of which, I began to think, that it was upon the swelling of this
+porous pith upon the access of moisture or water that the Beard, being made
+longer in the midst, was streightned, and by the shrinking or subsiding of
+the parts of that Spongie substance together, when the water or moisture
+was exhal'd or dried, the pith or middle parts growing shorter, the whole
+became twisted.
+
+But this I cannot be positive in, for upon cutting the wreath'd part in
+many places transversly, I was not so well satisfy'd with the shape and
+manner of the pores of the pith; for looking on these transverse Sections
+with a very good _Microscope_, I found that the ends of those transverse
+Sections appear'd much of the manner of the third Figure of the 15.
+_scheme_ ABCFE, and the middle of pith CC, seem'd very full of pores
+indeed, but all of them seem'd to run the long-ways.
+
+This Figure plainly enough shews in what manner those clefts, K and L
+divided the wreath'd Cylinder into two unequal parts, and also of what kind
+of substance the whole body consists; for by cutting the same Beard in many
+places, with transverse Sections, I found much the same appearance with
+this express'd; so that those pores seem to run, as in most other such Cany
+bodies, the whole length of it.
+
+The clefts of this body KK, and LL, seem'd (as is also express'd in the
+Figure) to wind very oddly in the inner part of the wreath, and in some
+parts of them, they seem'd stuffed, as it were, with that Spongie
+substance, which I just now described.
+
+This so oddly constituted Vegetable substance, is first (that I have met
+with) taken notice of by _Baptista Porta_, in his _Natural Magick_, as a
+thing known to children and Juglers, and it has been call'd by some of
+those last named persons, the better to cover their cheat, the Legg of an
+_Arabian Spider_, or the Legg of an inchanted _Egyptian fly_, and has been
+used by them to make a small Index, Cross, or the like, to move round upon
+the wetting of it with a drop of Water, and muttering certain words.
+
+But the use that has been made of it, for the discovery of the various
+constitutions of the Air, as to driness and moistness, is incomparably
+beyond any other, for this it does to admiration: The manner of contriving
+it so, as to perform this great effect, is onely thus:
+
+Provide a good large Box of Ivory, about four Inches over, and of what
+depth you shall judge convenient (according to your intention of making use
+of one, two, three, or more of these small Beards, ordered in the manner
+which I shall by and by describe) let all the sides of this Box be turned
+of Basket-work (which here in _London_ is easily enough procur'd) full of
+holes, in the manner almost of a Lettice, the bigger, or more the holes
+are, the better, that so the Air may have the more free passage to the
+inclosed Beard, and may the more easily pass through the Instrument; it
+will be better yet, though not altogether so handsom, if insteed of the
+Basket-work on the sides of the Box, the bottom and top of the Box be
+join'd together onely with three or four small Pillars, after the manner
+represented in the 4. Figure of the 15. _Scheme_. Or, if you intend to make
+use of many of these small Beards join'd together, you may have a small
+long Case of Ivory, whose sides are turn'd of Basket-work, full of holes,
+which may be screw'd on to the underside of a broad Plate of Ivory, on the
+other side of which is to be made the divided Ring or Circle, to which
+divisions the pointing of the Hand or Index, which is moved by the
+conjoin'd Beard, may shew all the _Minute_ variations of the Air.
+
+There may be multitudes of other ways for contriving this small Instrument,
+so as to produce this effect, which any one may, according to his peculiar
+use, and the exigency of his present occasion, easily enough contrive and
+take, on which I shall not therefore insist. The whole manner of making any
+one of them is thus: Having your Box or frame AABB, fitly adapted for the
+free passage of the Air through it, in the midst of the bottom BBB, you
+must have a very small hole C, into which the lower end of the Beard is to
+be fix'd, the upper end of which Beard ab, is to pass through a small hole
+of a Plate, or top AA, if you make use onely of a single one, and on the
+top of it e, is to be fix'd a small and very light _Index_ fg, made of a
+very thin sliver of a Reed or Cane; but if you make use of two or more
+Beards, they must be fix'd and bound together, either with a very fine
+piece of Silk, or with a very small touch of hard Wax, or Glew, which is
+better, and the _Index_ fg, is to be fix'd on the top of the second, third,
+or fourth in the same manner as on the single one.
+
+Now, because that in every of these contrivances, the _Index_ fg, will with
+some temperatures of Air, move two, three, or more times round, which
+without some other contrivance then this, will be difficult to distinguish,
+therefore I thought of this Expedient: The _Index_ or _Hand_ fg, being
+rais'd a pretty way above the surface of the Plate AA, fix in at a little
+distance from the middle of it a small Pin h, so as almost to touch the
+surface of the Plate AA, and then in any convenient place of the surface of
+the Plate, fix a small Pin, on which put on a small piece of Paper, or thin
+Past-board, Vellom, or Parchment, made of a convenient cize, and shap'd in
+the manner of that in the Figure express'd by ik, so that having a
+convenient number of teeth every turn or return of the Pin h, may move this
+small indented Circle, a tooth forward or backwards, by which means the
+teeth of the Circle, being mark'd, it will be thereby very easie to know
+certainly, how much variation any change of weather will make upon the
+small wreath'd body. In the making of this Secundary Circle of Vellom, or
+the like, great care is to be had, that it be made exceeding light, and to
+move very easily, for otherwise a small variation will spoil the whole
+operation. The Box may be made of Brass, Silver, Iron, or any other
+substance, if care be taken to make it open enough, to let the Air have a
+sufficiently free access to the Beard. The _Index_ also may be various ways
+contrived, so as to shew both the number of the revolutions it makes, and
+the _Minute_ divisions of each revolution.
+
+I have made several trials and Instruments for discovering the driness and
+moisture of the Air with this little wreath'd body, and find it to vary
+exceeding sensibly with the least change in the constitution of the Air, as
+to driness and moisture, so that with one breathing upon it, I have made it
+untwist a whole bout, and the _Index_ or _Hand_ has shew'd or pointed to
+various divisions on the upper Face or Ring of the Instrument, according as
+it was carried neerer and neerer to the fire, or as the heat of the Sun
+increased upon it.
+
+Other trials I have made with Gut-strings, but find them nothing neer so
+sensible, though they also may be so contriv'd as to exhibit the changes of
+the Air, as to driness and moisture, both by their stretching and shrinking
+in length, and also by their wreathing and unwreathing themselves; but
+these are nothing neer so exact or so tender, for their varying property
+will in a little time change very much. But there are several other
+Vegetable substances that are much more sensible then even this Beard of a
+wilde _Oat_; such I have found the Beard of the seed of Musk-grass, or
+_Geranium moschatum_, and those of other kinds of _Cranes-bil_ seeds, and
+the like. But always the smaller the wreathing substance be, the more
+sensible is it of the mutations of the Air, a conjecture at the reason of
+which I shall by and by add.
+
+The lower end of this wreath'd Cylinder being stuck upright in a little
+soft Wax, so that the bended part or _Index_ of it lay _horizontal_, I have
+observ'd it always with moisture to unwreath it self from the East (For
+instance) by the South to the West, and so by the North to the East again,
+moving with the Sun (as we commonly say) and with heat and drouth to
+re-twist; and wreath it self the contrary way, namely, from the East, (for
+instance) by the North to the West, and so onwards.
+
+The cause of all which _Phaenomena_, seems to be the differing texture of
+the parts of these bodies, each of them (especially the Beard of a wilde
+_Oat_, and of _Mosk-grass_ seed) seeming to have two kind of substances,
+one that is very porous, loose, and spongie, into which the watry steams of
+the Air may be very easily forced, which will be thereby swell'd and
+extended in its dimensions, just as we may observe all kind of Vegetable
+substance upon steeping in water to swell and grow bigger and longer. And a
+second that is more hard and close, into which the water can very little,
+or not at all penetrate, this therefore retaining always very neer the same
+dimensions, and the other stretching and shrinking, according as there is
+more or less moisture or water in its pores, by reason of the make and
+shape of the parts, the whole body must necessarily unwreath and wreath it
+self.
+
+And upon this Principle, it is very easie to make several sorts of
+contrivances that should thus wreath and unwreath themselves, either by
+heat and cold, or by driness and moisture, or by any greater or less force,
+from whatever cause it proceed, whether from gravity or weight, or from
+wind which is motion of the Air, or from some springing body, or the like.
+
+This, had I time, I should enlarge much more upon; for it seems to me to be
+the very first footstep of _Sensation_, and Animate motion, the most plain,
+simple, and obvious contrivance that Nature has made use of to produce a
+motion; next to that of Rarefaction and Condensation by heat and cold. And
+were this Principle very well examin'd, I am very apt to think, it would
+afford us a very great help to find out the _Mechanism_ of the Muscles,
+which indeed, as farr as I have hitherto been able to examine, seems to me
+not so very perplex as one might imagine, especially upon the examination
+which I made of the Muscles of _Crabs_, _Lobsters_, and several sorts of
+large Shell-fish, and comparing my Observations on them, with the
+circumstances I observ'd in the muscles of terrestrial Animals.
+
+Now, as in this Instance of the Beard of a wilde _Oat_, we see there is
+nothing else requisite to make it wreath and unwreath it self, and to
+streighten and bend its knee, then onely a little breath of moist or dry
+Air, or a small _atome_ almost of water or liquor, and a little heat to
+make it again evaporate, for, by holding this Beard, plac'd and fix'd as I
+before directed, neer a Fire, and dipping the tip of a small shred of Paper
+in well rectify'd spirit of Wine, and then touching the wreath'd
+_Cylindrical_ part, you may perceive it to untwist it self; and presently
+again, upon the _avolation_ of the spirit, by the great heat, it will
+re-twist it self, and thus will it move forward and backwards as oft as you
+repeat the touching it with the spirit of Wine; so may, perhaps, the
+shrinking and relaxing of the muscles be by the influx and evaporation of
+some kind of liquor or juice. But of this Enquiry I shall add more
+elsewhere.
+
+       *       *       *       *       *
+
+
+Observ. XXVIII. _Of the Seeds of _Venus_ looking-glass, or _Corn_ Violet._
+
+From the Leaves, and Downs, and Beards of Plants, we come at last to the
+Seeds; and here indeed seems to be the Cabinet of Nature, wherein are laid
+up its Jewels. The providence of Nature about Vegetables, is in no part
+manifested more, then in the various contrivances about the seed, nor
+indeed is there in any part of the Vegetable so curious carvings, and
+beautifull adornments, as about the seed; this in the larger sorts of seeds
+is most evident to the eye; nor is it lest manifest through the
+_Microscope_, in those seeds whose shape and structure, by reason of their
+smalness, the eye is hardly able to distinguish.
+
+Of these there are multitudes, many of which I have observ'd through a
+_Microscope_, and find, that they do, for the most part, every one afford
+exceeding pleasant and beautifull objects. For besides those that have
+various kinds of carv'd surfaces, there are other that have smooth and
+perfectly polish'd surfaces, others a downy hairy surface; some are cover'd
+onely with a skin, others with a kind of shell, others with both, as is
+observable also in greater seeds.
+
+Of these seeds I have onely described four sorts which may serve as a
+_specimen_ of what the inquisitive observers are likely to find among the
+rest. The first of these seeds which are described in the 17. _Scheme_, are
+those of Corn-Violets, the seed is very small, black, and shining, and, to
+the naked eye, looks almost like a very small Flea; But through the
+_Microscope_, it appears a large body, cover'd with a tough thick and
+bright reflecting skin very irregularly shrunk and pitted, insomuch that
+it is almost an impossibility to find two of them wrinkled alike, so great
+a variety may there be even in this little seed.
+
+This, though it appear'd one of the most promising seeds for beauty to the
+naked eye, yet through the _Microscope_ it appear'd but a rude mishapen
+seed, which I therefore drew, that I might thereby manifest how unable we
+are by the naked eye to judge of beauteous or less curious _microscopical_
+Objects; cutting some of them in sunder, I observ'd them to be fill'd with
+a greenish yellow pulp, and to have a very thick husk, in proportion to the
+pulp.
+
+       *       *       *       *       *
+
+
+Observ. XXIX. _Of the Seeds of _Tyme_._
+
+These pretty fruits here represented, in the 18. _Scheme_, are nothing
+else, but nine several seeds of Tyme; they are all of them in differing
+posture, both as to the eye and the light; nor are they all of them exactly
+of the same shape, there being a great variety both in the bulk and figure
+of each seed; but they all agreed in this, that being look'd on with a
+_Microscope_, they each of them exactly resembled a Lemmon or Orange dry'd;
+and this both in shape and colour. Some of them are a little rounder, of
+the shape of an Orange, as A and B, they have each of them a very
+conspicuous part by which they were join'd to their little stalk, and one
+of them had a little piece of stalk remaining on; the opposite side of the
+seed, you may perceive very plainly by the Figure, is very copped and
+prominent, as is very usual in Lemmons; which prominencies are express'd in
+D, E and F.
+
+They seem'd each of them a little creas'd or wrinckled, but E was very
+conspicuously furrow'd, as if the inward make of this seed had been
+somewhat like that of a Lemmon also, but upon dividing several seeds with a
+very sharp Pen-knife, and examining them afterward, I found their make to
+be in nothing but bulk differing from that of Peas, that is, to have a
+pretty thick coat, and all the rest an indifferent white pulp, which seem'd
+very close; so that it seems Nature does not very much alter her method in
+the manner of inclosing and preserving the vital Principle in the seed, in
+these very small grains, from that of Beans, Peas, &c.
+
+The Grain affords a very pretty Object for the _Microscope_, namely, a Dish
+of Lemmons plac'd in a very little room; should a Lemmon or Nut be
+proportionably magnify'd to what this seed of Tyme is, it would make it
+appear as bigg as a large Hay-reek and it would be no great wonder to see
+_Homers Iliads_, and _Homer_ and all, cramm'd into such a Nutshell. We may
+perceive even in these small Grains, as well as in greater, how curious and
+carefull Nature is in preserving the seminal principle of Vegetable bodies,
+in what delicate, strong and most convenient Cabinets she lays them and
+closes them in a pulp for their safer protection from outward dangers, and
+for the supply of convenient alimental juice, when the heat of the Sun
+begins to animate and move these little _automatons_ or Engines; as if she
+would, from the ornaments wherewith she has deckt these Cabinets, hint to
+us, that in them she has laid up her Jewels and Master-pieces. And this, if
+we are but diligent in observing, we shall find her method throughout.
+There is no curiosity in the Elemental kingdom, if I may so call the bodies
+of Air, Water, Earth, that are comparable in form to those of Minerals, Air
+and Water having no form at all, unless a potentiality to be form'd into
+Globules; and the clods and parcels of Earth are all irregular, whereas in
+Minerals she does begin to _Geometrize_, and practise, as 'twere, the first
+principles of _Mechanicks_, shaping them of plain regular figures, as
+triangles, squares, &c. and _tetraedrons_, cubes, &c. But none of their
+forms are comparable to the more compounded ones of Vegetables; For here
+she goes a step further, forming them both of more complicated shapes, and
+adding also multitudes of curious Mechanick contrivances in their
+structure; for whereas in Vegetables there was no determinate number of the
+leaves or branches, nor no exacly certain figure of leaves, or flowers, or
+seeds, in Animals all those things are exactly defin'd and determin'd; and
+where-ever there is either an excess or defect of those determinate parts
+or limbs, there has been some impediment that has spoil'd the principle
+which was most regular: Here we shall find, not onely most curiously
+compounded shapes, but most stupendious Mechanisms and contrivances, here
+the ornaments are in the highest perfection, nothing in all the Vegetable
+kingdom that is comparable to the deckings of a Peacock; nay, to the
+curiosity of any feather, as I elsewhere shew; nor to that of the smallest
+and most despicable Fly. But I must not stay on these speculations, though
+perhaps it were very well worth while for one that had leisure, to see what
+Information may be learn'd of the nature, or use, or virtues of bodies, by
+their several forms and various excellencies and properties. Who knows but
+_Adam_ might from some such contemplation, give names to all creatures? If
+at least his names had any significancy in them of the creatures nature on
+which he impos'd it; as many (upon what grounds I know not) have suppos'd:
+And who knows, but the Creator may, in those characters, have written and
+engraven many of his most mysterious designs and counsels, and given man a
+capacity, which, assisted with diligence and industry, may be able to read
+and understand them. But not to multiply my digression more then I can the
+time, I will proceed to the next, which is,
+
+       *       *       *       *       *
+
+
+Observ. XXX. _Of the Seeds of _Poppy_._
+
+The small seeds of Poppy, which are described in the 19. _Scheme_, both for
+their smalness, multiplicity and prettiness, as also for their admirable
+soporifick quality, deserve to be taken notice of among the other
+_microscopical_ seeds of Vegetables: For first, though they grow in a Case
+or Hive oftentimes bigger then one of these Pictures of the _microscopical_
+appearance, yet are they for the most part so very little, that they exceed
+not the bulk of a small Nitt, being not above 1/32 part of an Inch in
+Diameter, whereas the Diameter of the Hive of them oftentimes exceeds two
+Inches, so that it is capable of containing near two hundred thousand, and
+so in all likelihood does contain a vast quantity, though perhaps not that
+number. Next, for their prettiness, they may be compar'd to any
+_microscopical_ seed I have yet seen; for they are of a dark brownish red
+colour, curiously Honey-comb'd all over with a very pretty variety of
+Net-work, or a small kind of imbosment of very orderly rais'd ridges, the
+surface of them looking not unlike the inside of a Beev's stomack. But that
+which makes it most considerable of all, is, the medicinal virtues of it,
+which are such as are not afforded us by any Mineral preparation; and that
+is for the procuring of sleep, a thing as necessary to the well-being of a
+creature as his meat, and that which refreshes both the voluntary and
+rational faculties, which, whil'st this affection has seis'd the body, are
+for the most part unmov'd, and at rest. And, methinks, Nature does seem to
+hint some very notable virtue or excellency in this Plant from the
+curiosity it has bestow'd upon it. First, in its flower, it is of the
+highest scarlet-Dye, which is indeed the prime and chiefest colour, and has
+been in all Ages of the world most highly esteem'd: Next, it has as much
+curiosity shew'd also in the husk or case of the seed, as any one Plant I
+have yet met withall; and thirdly, the very seeds themselves, the
+_Microscope_ discovers to be very curiously shap'd bodies; and lastly,
+Nature has taken such abundant care for the propagation of it, that one
+single seed grown into a Plant, is capable of bringing some hundred
+thousands of seeds.
+
+It were very worthy some able man's enquiry whether the intention of
+Nature, as to the secundary end of Animal and Vegetable substances might
+not be found out by some such characters and notable impressions as these,
+or from divers other circumstances, as the figure, colour, place, time of
+flourishing, springing and fading, duration, taste, smell, &c. For if such
+there are (as an able _Physician_ upon good grounds has given me cause to
+believe) we might then, insteed of studying Herbals (where so little is
+deliver'd of the virtues of a Plant, and less of truth) have recourse to
+the Book of Nature it self, and there find the most natural, usefull, and
+most effectual and specifick Medicines, of which we have amongst
+Vegetables, two very noble Instances to incourage such a hope, the one of
+the _Jesuite powder_ for the cure of _intermitting Feavers_, and the other
+of the juice of _Poppy_ for the curing the defect of sleeping.
+
+       *       *       *       *       *
+
+
+Observ. XXXI. _Of _Purslane-seed_._
+
+The Seeds of _Purslane_ seem of very notable shapes, appearing through the
+_Microscope_ shap'd somewhat like a _nautilus_ or _Porcelane_ shell, as may
+be seen in the XX. _Scheme_, it being a small body, coyl'd round in the
+manner of a Spiral, at the greater end whereof, which represents the mouth
+or orifice of the Shell, there is left a little white transparent
+substance, like a skin, represented by BBBB, which seems to have been the
+place whereunto the stem was join'd. The whole surface of this _Coclea_ or
+Shell, is cover'd over with abundance of little _prominencies_ or buttons
+very orderly rang'd into Spiral rows, the shape of each of which seem'd
+much to resemble a Wart upon a mans hand. The order, variety, and curiosity
+in the shape of this little seed, makes it a very pleasant object for the
+_Microscope_, one of them being cut asunder with a very sharp Penknife,
+discover'd this carved Casket to be of a brownish red, and somewhat
+transparent substance, and manifested the inside to be fill'd with a
+whitish green substance or pulp, the Bed wherein the seminal principle lies
+_invelop'd_.
+
+There are multitudes of other seeds which in shape represent or imitate the
+forms of divers other sorts of Shells: as the seed of _Scurvy-grass_ very
+much resembles the make of a _Concha Venerea_, a kind of Purcelane Shell;
+others represent several sorts of larger fruits, sweat Marjerome and
+Pot-marjerome represent Olives. Carret seeds are like a cleft of a Coco-Nut
+Husk, others are like Artificial things, as Succory seeds are like a Quiver
+full of Arrows, the seeds of _Amaranthus_ are of an exceeding lovely shape,
+somewhat like an Eye: The skin of the black and shrivled seeds of Onyons
+and Leeks, are all over knobbed like a Seals skin. Sorrel has a pretty
+black shining three-square seed, which is picked at both ends with three
+ridges, that are bent the whole length of it. It were almost endless to
+reckon up the several shapes, they are so many and so various; Leaving them
+therefore to the curious observer, I shall proceed to the Observations on
+the parts of Animals.
+
+       *       *       *       *       *
+
+
+Observ. XXXII. _Of the Figure of several sorts of _Hair_, and of the
+texture of the _skin_._
+
+Viewing some of the Hairs of my Head with a very good _Microscope_, I took
+notice of these particulars:
+
+1. That they were, for the most part, _Cylindrical_, some of them were
+somewhat _Prismatical_, but generally they were very neer round, such as
+are represented in the second Figure of the 5. _Scheme_, by the _Cylinders_
+EEE. nor could I find any that had sharp angules.
+
+2. That that part which was next the top, was bigger then that which was
+neerer the root.
+
+3. That they were all along from end to end transparent, though not very
+cleer, the end next the root appearing like a black transparent piece of
+Horn, the end next the top more brown, somewhat like transparent Horn.
+
+4. That the root of the Hairs were pretty smooth, tapering inwards, almost
+like a Parsneb; nor could I find that it had any filaments, or any other
+vessels, such as the _fibres_ of Plants.
+
+5. That the top when split (which is common in long Hair) appear'd like the
+end of a stick, beaten till it be all flitter'd, there being not onely two
+splinters, but sometimes half a score and more.
+
+6. That they were all, as farr as I was able to find, solid _Cylindrical_
+bodies, not pervious, like a Cane or Bulrush; nor could I find that they
+had any Pith, or distinction of Rind, or the like, such as I had observ'd
+in Horse-hairs, the Bristles of a Cat, the _Indian_ Deer's Hair, &c.
+
+_Observations on several other sorts of _Hair_._
+
+For the Brisles of a Hogg, I found them to be first a hard transparent
+horny substance, without the least appearance of pores or holes in it; and
+this I try'd with the greatest care I was able, cutting many of them with a
+very sharp Razor, so that they appear'd, even in the Glass, to have a
+pretty smooth surface, but somewhat waved by the sawing to and fro of the
+Razor, as is visible in the end of the _Prismatical_ body A of the same
+Figure; and then making trials with causing the light to be cast on them
+all the various ways I could think of, that was likely to make the pores
+appear, if there had been any, I was not able to discover any.
+
+Next, the Figure of the Brisles was very various, neither perfectly round,
+nor sharp edg'd, but _Prismatical_, with divers sides, and round angles, as
+appears in the Figure A. The bending of them in any part where they before
+appear'd cleer, would all flaw them, and make them look white.
+
+The Mustacheos of a Cat (part of one of which is represented by the short
+_Cylinder_ B of the same Figure) seem'd to have, all of them that I
+observ'd, a large pith in the middle, like the pith of an Elder, whose
+texture was so close, that I was not able to discover the least sign of
+pores; and those parts which seem to be pores, as they appear'd in one
+position to the light, in another I could find a manifest reflection to be
+cast from them.
+
+This I instance in, to hint that it is not safe to conclude any thing to be
+positively this or that, though it appear never so plain and likely when
+look'd on with a _Microscope_ in one posture, before the same be examin'd
+by placing it in several other positions.
+
+And this I take to be the reason why many have believed and asserted the
+Hairs of a man's head to be hollow, and like so many small pipes perforated
+from end to end.
+
+Now, though I grant that by an _Analogie_ one may suppose them so, and from
+the _Polonian_ disease one may believe them such, yet I think we have not
+the least encouragement to either from the _Microscope_, much less
+positively to assert them such. And perhaps the very essence of the _Plica
+Polonica_ may be the hairs growing hollow, and of an unnatural
+constitution.
+
+And as for the _Analogie_, though I am apt enough to think that the hairs
+of several Animals may be perforated somewhat like a Cane, or at least have
+a kind of pith in them, first, because they seem as 'twere a kind of
+Vegetable growing on an Animal, which growing, they say, remains a long
+while after the Animal is dead, and therefore should like other Vegetables
+have a pith; and secondly, because Horns and Feathers, and Porcupine's
+Quils, and Cats Bristles, and the long hairs of Horses, which come very
+neer the nature of a mans hair, seem all of them to have a kind of pith,
+and some of them to be porous, yet I think it not (in these cases, where we
+have such helps for the sense as the _Microscope_ affords) safe concluding
+or building on more then we sensibly know, since we may, with examining,
+find that Nature does in the make of the same kind of substance, often vary
+her method in framing of it: Instances enough to confirm this we may find
+in the Horns of several creatures: as what a vast difference is there
+between the Horns of an Oxe, and those of some sorts of Staggs as to their
+shape? and even in the hairs of several creatures, we find a vast
+difference, as the hair of a man's head seems, as I said before, long,
+_Cylindrical_ and sometime a little _Prismatical_, solid or impervious, and
+very small; the hair of an _Indian_ Deer (a part of the middle of which is
+described in the third Figure of the fifth _Scheme_, marked with F) is
+bigger in compass through all the middle of it, then the Bristle of an
+Hogg, but the end of it is smaller then the hair of any kind of Animal (as
+may be seen by the Figure G) the whole belly of it, which is about two or
+three Inches long, looks to the eye like a thread of course Canvass, that
+has been newly unwreath'd, it being all wav'd or bended to and fro, much
+after that manner, but through the _Microscope_, it appears all perforated
+from side to side, and Spongie, like a small kind of spongy Coral, which is
+often found upon the _English_ shores; but though I cut it transversly, I
+could not perceive that it had any pores that ran the long-way of the hair:
+the long hairs of Horses CC and D, seem _Cylindrical_ and somewhat pithy;
+the Bristles of a Cat B, are conical and pithy: the Quils of Porcupines and
+Hedghoggs, being cut transversly, have a whitish pith, in the manner of a
+Starr, or Spur-rowel: Piggs-hair (A) is somewhat _triagonal_, and seems to
+have neither pith nor pore: And other kinds of hair have quite a differing
+structure and form. And therefore I think it no way agreeable to a true
+natural Historian, to pretend to be so sharp-sighted, as to see what a
+pre-conceiv'd _Hypothesis_ tells them should be there, where another man,
+though perhaps as seeing, but not forestall'd, can discover no such matter.
+
+But to proceed; I observ'd several kind of hairs that had been Dyed, and
+found them to be a kind of horny _Cylinder_, being of much about the
+transparency of a pretty cleer piece of Oxe horn; these appear'd quite
+throughout ting'd with the colours they exhibited. And 'tis likely, that
+those hairs being boyl'd or steep'd in those very hot ting'd liquors in the
+Dye-fat, And the substance of the hair being much like that of an Oxes
+Horn, the penetrant liquor does so far mollifie and soften the substance,
+that it sinks into the very center of it, and so the ting'd parts come to
+be mix'd and united with the very body of the hair, and do not (as some
+have thought) only stick on upon the outward surface. And this, the boiling
+of Horn will make more probable; for we shall find by that action, that the
+water will insinuate it self to a pretty depth within the surface of it,
+especially if this penetrancy of the water be much helped by the Salts that
+are usually mix'd with the Dying liquors. Now, whereas Silk may be dyed or
+ting'd into all kind of colours without boiling or dipping into hot
+liquors, I ghess the reason to be two-fold: First, because the filaments,
+or small cylinders of Silk, are abundantly smaller and finer, and so have a
+much less depth to be penetrated then most kind of hairs; and next, because
+the substance or matter of Silk, is much more like a Glew then the
+substance of Hair is. And that I have reason to suppose: First, because
+when it is spun or drawn out of the Worm, it is a perfect glutinous
+substance, and very easily sticks and cleaves to any adjacent body, as I
+have several times observed, both in Silk-worms and Spiders. Next, because
+that I find that water does easily dissolve and mollifie the substance
+again, which is evident from their manner of ordering those bottoms or pods
+of the Silk-worm before they are able to unwind them. It is no great wonder
+therefore, if those Dyes or ting'd liquors do very quickly mollifie and
+tinge the surfaces of so small and so glutinous a body. And we need not
+wonder that the colours appear so lovely in the one, and so dull in the
+other, if we view but the ting'd cylinders of both kinds with a good
+_Microscope_; for whereas the substance of Hair, at best, is but a dirty
+duskish white somewhat transparent, the filaments of Silk have a most
+lovely transparency and cleerness, the difference between those two being
+not much less then that between a piece of Horn, and a piece of Crystal;
+the one yielding a bright and vivid reflection from the concave side of the
+cylinder, that is, from the concave surface of the Air that incompasses the
+back-part of the cylinder; the other yielding a dull and perturb'd
+reflection from the several _Heterogeneous_ parts that compose it. And this
+difference will be manifest enough to the eye, if you get a couple of small
+Cylinders, the smaller of Crystal Glass, the other of Horn, and then
+varnishing them over very thinly with some transparent colour, which will
+represent to the naked eye much the same kind of object which is
+represented to it from the filaments of Silk and Hair by the help of the
+_Microscope_. Now, since the threads of Silk and Serge are made up of a
+great number of these filaments, we may henceforth cease to wonder at the
+difference. From much the same reason proceeds the vivid and lovely colours
+of Feathers, wherein they very farr exceed the natural as well as
+Artificial colours of hair, of which I shall say more in its proper place.
+
+The Teguments indeed of creatures are all of them adapted to the peculiar
+use and convenience of that Animal which they inwrap; and very much also
+for the ornament and beauty of it, as will be most evident to any one that
+shall attentively consider the various kinds of cloathings wherewith most
+creatures are by Nature invested and cover'd. Thus I have observed, that
+the hair or furr of those Northern white Bears that inhabite the colder
+Regions, is exceeding thick and warm: the like have I observ'd of the hair
+of a _Greenland_ Deer, which being brought alive to _London_, I had the
+opportunity of viewing; its hair was so exceeding thick, long and soft,
+that I could hardly with my hand, grasp or take hold of his skin, and it
+seem'd so exceeding warm, as I had never met with any before. And as for
+the ornamentative use of them, it is most evident in a multitude of
+creatures, not onely for colour, as the Leopards, Cats, Rhein Deer, _&c_.
+but for the shape, as in Horses manes, Cats beards, and several other of
+the greater sort of terrestrial Animals, but is much more conspicuous, in
+the Vestments of Fishes, Birds, Insects, of which I shall by and by give
+some Instances.
+
+As for the skin, the _Microscope_ discovers as great a difference between
+the texture of those several kinds of Animals, as it does between their
+hairs; but all that I have yet taken notice of, when tann'd or dress'd, are
+of a Spongie nature, and seem to be constituted of an infinite company of
+small long _fibres_ or hairs, which look not unlike a heap of Tow or Okum;
+every of which _fibres_ seem to have been some part of a Muscle, and
+probably, whil'st the Animal was alive, might have its distinct function,
+and serve for the contraction and relaxation of the skin, and for the
+stretching and shrinking of it this or that way.
+
+And indeed, without such a kind of texture as this, which is very like that
+of _Spunk_ it would seem very strange, how any body so strong as the skin
+of an Animal usually is, and so close as it seems, whil'st the Animal is
+living, should be able to suffer so great an extension any ways, without at
+all hurting or dilacerating any part of it. But, since we are inform'd by
+the _Microscope_, that it consists of a great many small filaments, which
+are implicated, or intangled one within another, almost no otherwise then
+the hairs in a lock of Wool, or the flakes in a heap of Tow, though not
+altogether so loose, but the filaments are here and there twisted, as
+'twere, or interwoven, and here and there they join and unite with one
+another, so as indeed the whole skin seems to be but one piece, we need not
+much wonder: And though these _fibres_ appear not through a _Microscope_
+exactly jointed and contex'd, as in Sponge; yet, as I formerly hinted, I am
+apt to think, that could we find some way of discovering the texture of it,
+whil'st it invests the living Animal, or had some very easie way of
+separating the pulp or intercurrent juices, such as in all probability fill
+those _Interstitia_, without dilacerating, brusing, or otherwise spoiling
+the texture of it (as it seems to be very much by the ways of tanning and
+dressing now us'd) we might discover a much more curious texture then I
+have hitherto been able to find; perhaps somewhat like that of Sponges.
+
+That of _Chamoise_ Leather is indeed very much like that of _Spunk_, save
+onely that the _filaments_ seem nothing neer so even and round, nor
+altogether so small, nor has it so curious joints as _Spunk_ has, some of
+which I have lately discover'd like those of a Sponge, and perhaps all
+these three bodies may be of the same kind of substance, though two of them
+indeed are commonly accounted Vegetable (which, whether they be so or no, I
+shall not now dispute) But this seems common to all three, that they
+undergo a tanning or dressing, whereby the interspers'd juices are wasted
+and wash'd away before the texture of them can be discover'd.
+
+What their way is of dressing, or curing Sponges, I confess, I cannot
+learn; but the way of dressing _Spunk_, is, by boiling it a good while in a
+strong _Lixivium_, and then beating it very well; and the manner of
+dressing Leather is sufficiently known.
+
+It were indeed extremely desirable, if such a way could be found whereby
+the _Parenchyma_ or flesh of the Muscles, and several other parts of the
+body, might be wash'd, or wafted clean away, without vitiating the form of
+the _fibrous_ parts or vessells of it, for hereby the texture of thole
+parts, by the help of a good _Microscope_, might be most accurately found.
+
+But to digress no further, we may, from this discovery of the _Microscope_,
+plainly enough understand how the skin, though it looks so close as it
+does, comes to give a passage to so vast a quantity of _excrementitious_
+substances, as the diligent _Sanctorius_ has excellently observed it to do,
+in his _medicina statica_; for it seems very probable, from the texture
+after dressing, that there are an infinit of pores that every way pierce
+it, and that those pores are onely fill'd with some kind of juice, or some
+very pulpy soft substance, and thereby the steams may almost as easily find
+a passage through such a fluid _vehicle_ as the vaporous bubbles which are
+generated at the bottom of a Kettle of hot water do find a passage through
+that fluid _medium_ into the ambient Air.
+
+Nor is the skin of animals only thus pervious, but even those of vegetables
+also seem to be the same; for otherwise I cannot conceive why, if two
+sprigs of Rosemary (for Instance) be taken as exactly alike in all
+particulars as can be, and the one be set with the bottom in a Glass of
+water, and the other be set just without the Glass, but in the Air onely,
+though you stop the lower end of that in the Air very carefully with Wax,
+yet shall it presently almost wither, whereas the other that seems to have
+a supply from the subjacent water by its small pipes, or _microscopical_
+pores, preserves its greenness for many days, and sometimes weeks.
+
+Now, this to me, seems not likely to proceed from any other cause then the
+_avolation_ of the juice through the skin; for by the Wax, all those other
+pores of the stem are very firmly and closely stop'd up. And from the more
+or less porousness of the skins or rinds of Vegetables may, perhaps, be
+somewhat of the reason given, why they keep longer green, or sooner wither;
+for we may observe by the bladdering and craking of the leaves of Bays,
+Holly, Laurel, &c. that their skins are very close, and do not suffer so
+free a passage through them of the included juices.
+
+But of this, and of the Experiment of the Rosemary, I shall elsewhere more
+fully consider, seeming to me an extreme luciferous Experiment, such as
+seems indeed very plainly to prove the _Schematism_ or structure of
+Vegetables altogether _mechanical_, and as necessary, that (water and
+warmth being apply'd to the bottom of the sprig of a Plant) some of it
+should be carried upwards into the stem, and thence distributed into the
+leaves, as that the water of the _Thames_ covering the bottom of the Mills
+at the Bridge foot of _London_, and by the ebbing and flowing of it,
+passing strongly by them, should have some part of it convey'd to the
+Cesterns above, and thence into several houses and Cesterns up and down the
+City.
+
+       *       *       *       *       *
+
+
+Observ. XXXIII. _Of the _Scales_ of a _Soal_, and other Fishes._
+
+Having hinted somewhat of the skin and covering of terrestrial Animals, I
+shall next add an Observation I made on the skin and Scales of a _Soal_, a
+small Fish, commonly enough known; and here in Fishes, as well as other
+Animals, Nature follows its usual method, framing all parts so, as that
+they are both usefull and ornamental in all its composures, mingling
+_utile_ and _dulce_ together; and both these designs it seems to follow,
+though our unassisted senses are not able to peceive them: This is not
+onely manifest in the covering of this Fish, but in multitudes of others,
+which it would be too long to enumerate, witness particularly that small
+Sand Shell, which I mention'd in the XI. Observation, and infinite other
+small Shells and Scales, divers of which I have view'd. This skin I view'd,
+was flead from a pretty large _Soal_, and then expanded and dry'd, the
+inside of it, when dry, to the naked eye, look'd very like a piece of
+Canvass, but the _Microscope_ discover'd that texture to be nothing else,
+but the inner ends of those curious Scolop'd Scales I, I, I, in the second
+_Figure_ of the XXI. _Scheme_, namely, the part of GGGG (of the larger
+representation of a single Scale, in the first _Figure_ of the same
+_Scheme_) which on the back side, through an ordinary single Magnifying
+Glass, look'd not unlike the Tyles on an house.
+
+The outside of it, to the naked eye, exhibited nothing more of ornament,
+save the usual order of ranging the Scales into a _triagonal_ form, onely
+the edges seem'd a little to shine, the finger being rubb'd from the
+tail-wards towards the head, the Scales seem'd to stay and raze it; But
+through an ordinary Magnifying glass, it exhibited a most curiously carved
+and adorned surface, such as is visible in the second _Figure_, each of
+those (formerly almost imperceptible) Scales appearing much of the shape I,
+I, I, that is, they were round, and protuberant, and somewhat shap'd like a
+Scolop, the whole Scale being creas'd with curiously wav'd and indented
+ridges, with proportionable furrows between; each of which was terminated
+with a very sharp transparent bony substance, which, like so many small
+Turnpikes, seem'd to arm the edges.
+
+The back part KKK was the skin into which each of these Scales were very
+deeply fix'd, in the curious regular order, visible in the second _Figure_.
+The length and shape of the part of the Scale which was buried by the skin,
+is evidenced by the first _Figure_; which is the representation of one of
+them pluck'd out and view'd through a good _Microscope_, namely, the part
+LFGGFL, wherein is also more plainly to be seen, the manner of carving of
+the scolopt part of every particular Scale, how each ridge or barr EEE is
+alternately hollowed or engraven, and how every gutter between them is
+terminated with very transparent and hard pointed spikes, and how every
+other of these, as AAAA, are much longer then the interjacent ones, DDD.
+
+The texture or form also of the hidden part appears, namely, the middle
+part, GGG, seems to consist of a great number of small quills or pipes, by
+which, perhaps, the whole may be nourished; and the side parts FF consist
+of a more fibrous texture, though indeed the whole Scale seem'd to be of a
+very tough gristly substance like the larger Scales of other Fishes.
+
+The Scales of the skin of a Dog-fish (which is us'd by such as work in
+Wood, for the smoothing of their work, and consists plainly enough to the
+naked eye, of a great number off small horny points) through the
+_Microscope_ appear'd each of them curiously ridg'd, and very neatly
+carved; and indeed, you can hardly look on the scales of any Fish, but you
+may discover abundance of curiosity and beautifying; and not only in these
+Fishes, but in the shells and crusts or armour of most sorts of _Marine_
+Animals so invested.
+
+       *       *       *       *       *
+
+
+Observ. XXXIV. _Of the Sting of a Bee._
+
+The Sting of a _Bee_, delineated in the second Figure of the XVI. _Scheme_,
+seems to be a weapon of offence, and is as great an Instance, that Nature
+did realy intend revenge as any, and that first, because there seems to be
+no other use of it. Secondly, by reason of its admirable shape, seeming to
+be purposely shap'd for that very end. Thirdly, from the virulency of the
+liquor it ejects, and the sad effects and symptoms that follow it.
+
+But whatever be the use of it, certain it is, that the structure of it is
+very admirable; what it appears to the naked eye, I need not describe, the
+thing being known almost to every one, but it appears through the
+_Microscope_, to consist of two parts, the one a sheath, without a chape or
+top, shap'd almost like the Holster of a Pistol, beginning at d, and ending
+at b, this sheath I could most plainly perceive to be hollow, and to
+contain in it, both a Sword or Dart, and the poisonous liquor that causes
+the pain. The sheath or case seem'd to have several joints or settings
+together, marked by fghiklmno, it was arm'd moreover neer the top, with
+several crooks or forks (pqrst) on one side, and (pqrstu) on the other,
+each of which seem'd like so many Thorns growing on a briar, or rather like
+so many Cat's Claws; for the crooks themselves seem'd to be little sharp
+transparent points or claws, growing out of little _protuberancies_ on the
+side of the sheath, which, by observing the Figure diligently, is easie
+enough to be perceiv'd; and from several particulars, I suppose the Animal
+has a power of displaying them, and shutting them in again as it pleases,
+as a Cat does its claws, or as an Adder or Viper can its teeth or fangs.
+
+The other part of the Sting was the Sword, as I may so call it, which is
+sheath'd, as it were, in it, the top of which ab appears quite through at
+the smaller end, just as if the chape of the sheath of a Sword were lost,
+and the end of it appear'd beyond the Scabbard; the end of this Dart(a) was
+very sharp, and it was arm'd likewise with the like Tenterhooks or claws
+with those of the sheath, such as (vxy, xyzz) these crooks, I am very apt
+to think, can be clos'd up also, or laid flat to the sides of the Sword
+when it is drawn into the Scabbard, as I have several times observ'd it to
+be, and can be spred again or extended when ever the Animal pleases.
+
+The consideration of which very pretty structure, has hinted to me, that
+certainly the use of these claws seems to be very considerable, as to the
+main end of this Instrument, for the drawing in, and holding the sting in
+the flesh; for the point being very sharp, the top of the Sting or Dagger
+(ab) is very easily thrust into an Animal's body, which being once entred,
+the Bee, by endeavouring to pull it into the sheath, draws (by reason of
+the crooks (vxy) and (xyzz) which lay hold of the skin on either side) the
+top of the sheath (tsrv) into the skin after it, and the crooks t, s, and
+r, v, being entred, when the Bee endeavours to thrust out the top of the
+sting out of the sheath again, they lay hold of the skin on either side,
+and do not onely keep the sheath from sliding back, but helps the top
+inwards, and thus, by an alternate and successive retracting and emitting
+of the Sting in and out of the sheath, the little enraged creature by
+degrees makes his revengfull weapon pierce the toughest and thickest Hides
+of his enemies, in so much that some few of these stout and resolute
+soldiers with these little engines, do often put to flight a huge masty
+Bear, one of their deadly enemies, and thereby shew the world how much more
+considerable in Warr a few skilfull Engineers and resolute soldiers
+politickly order'd, that know how to manage such engines, are, then a vast
+unweildy rude force, that confides in, and acts onely by, its strength. But
+(to proceed) that he thus gets in his Sting into the skin, I conjecture,
+because, when I have observ'd this creature living, I have found it to move
+the Sting thus, to and fro, and thereby also, perhaps, does, as 'twere,
+pump or force out the poisonous liquor, and make it hang at the end of the
+sheath about b in a drop. The crooks, I suppose also to be the cause why
+these angry creatures, hastily removing themselves from their revenge, do
+often leave these weapons behind them, sheath'd, as 'twere, in the flesh,
+and, by that means, cause the painfull symptoms to be greater, and more
+lasting, which are very probably caus'd, partly by the piercing and tearing
+of the skin by the Sting, but chiefly by the corrosive and poisonous liquor
+that is by this Syringe-pipe convey'd among the sensitive parts thereof and
+thereby more easily gnaws and corrodes those tender _fibres_: As I have
+shewed in the description of a Nettle and of Cowhage.
+
+       *       *       *       *       *
+
+
+Observ. XXXV. _Of the contexture and shape of the particles of _Feathers_._
+
+Examining several sorts of _Feathers_, I took notice of these particulars
+in all sorts of wing-Feathers, especially in those which serv'd for the
+beating of the air in the action of flying.
+
+That the outward surface of the Quill and Stem was of a very hard, stiff,
+and horny substance, which is obvious enough, and that the part above the
+Quill was fill'd with a very white and light pith, and, with the
+_Microscope_, I found this pith to be nothing else, but a kind of natural
+_congeries_ of small bubbles, the films of which seem to be of the same
+substance with that of the Quill, that is, of a stiff transparent horny
+substance.
+
+Which particular seems to me, very worthy a more serious consideration; For
+here we may observe Nature, as 'twere, put to its shifts, to make a
+substance, which shall be both light enough, and very stiff and strong,
+without varying from its own establish'd principles, which we may observe
+to be such, that very strong bodies are for the most part very heavie also,
+a strength of the parts usually requiring a density, and a density a
+gravity; and therefore should Nature have made a body so broad and so
+strong as a Feather, almost, any other way then what it has taken, the
+gravity of it must necessarily have many times exceeded this; for this pith
+seems to be like so many stops or cross pieces in a long optical tube,
+which do very much contribute to the strength of the whole, the pores of
+which were such, as that they seem'd not to have any communication with one
+another, as I have elsewhere hinted.
+
+But the Mechanism of Nature is usually so excellent, that one and the same
+substance is adapted to serve for many ends. For the chief use of this,
+indeed, seems to be for the supply of nourishment to the downy or feathery
+part of the stem; for 'tis obvious enough in all sorts of Feathers, that
+'tis plac'd just under the roots of the branches that grow out of either
+side of the quill or stalk, and is exactly shap'd according to the ranking
+of those branches, coming no lower into the quill, then just the beginning
+of the downy branches, and growing onely on the under side of of the quill
+where those branches do so. Now, in a ripe Feather (as one may call it) it
+seems difficult to conceive how the _Succus nutritius_ should be convey'd
+to this pith; for it cannot, I think, be well imagin'd to pass through the
+substance of the quill, since, having examin'd it with the greatest
+diligence I was able, I could not find the least appearance of pores; but
+he that shall well examine an unripe or pinn'd Feather, will plainly enough
+perceive the Vessel for the conveyance of it to be the thin filmy pith (as
+'tis call'd) which passes through the middle of the quill.
+
+As for the make and contexture of the Down it self, it is indeed very rare
+and admirable, and such as I can hardly believe, that the like is to be
+discover'd in any other body in the world; for there is hardly a large
+Feather in the wing of a Bird, but contains neer a million of distinct
+parts, and every one of them shap'd in a most regular & admirable form,
+adapted to a particular Design: For examining a middle ciz'd Goose-quill, I
+easily enough found with my naked eye, that the main stem of it contain'd
+about 300. longer and more Downy branchings upon one side, and as many on
+the other of more stiff but somewhat shorter branchings. Many of these long
+and downy branchings, examining with an ordinary _Microscope_, I found
+divers of them to contain neer 1200. small leaves (as I may call them, such
+as EF of the first Figure of the 22. _Scheme_) and as many stalks on the
+other side, such as IK of the same Figure, each of the leaves or
+branchings, EF, seem'd to be divided into about sixteen or eighteen small
+joints, as may be seen plainly enough in the Figure, out of most of which
+there seem to grow small long _fibres_, such as are express'd in the
+Figure, each of them very proportionably shap'd according to its position,
+or place on the stalk EF; those on the under side of it, namely, 1, 2, 3,
+4, 5, 6, 7, 8, 9, &c. being much longer then those directly opposite to
+them on the upper; and divers of them, such as 2, 3, 4, 5, 6, 7, 8, 9, &c.
+were terminated with small crooks, much resembling those small crooks,
+which are visible enough to the naked eye, in the seed-buttons of
+Bur-docks. The stalks likewise, IK on the other side, seem'd divided into
+neer as many small knotted joints, but without any appearance of strings or
+crooks, each of them about the middle K, seem'd divided into two parts by a
+kind of fork, one side of which, namely, KL, was extended neer the length
+of KI, the other, M, was very short.
+
+The transverse Sections of the stems of these branchings, manifested the
+shape or figure of it to be much like INOE, which consisted of a horny skin
+or covering, and a white seemingly frothy pith, much like the make of the
+main stem of a Feather.
+
+The use of this strange kind of form, is indeed more admirable then all the
+rest, and such as deserves to be much more seriously examin'd and
+consider'd, then I have hitherto found time or ability to do; for
+certainly, it may very much instruct us in the nature of the Air,
+especially as to some properties of it.
+
+The stems of the Downy branches INOE, being rang'd in the order visible
+enough to the naked eye, at the distance of IF, or somewhat more, the
+_collateral_ stalks and leaves (if I may so call those bodies I newly
+described) are so rang'd, that the leaves or hairy stalks of the one side
+lie at top, or are incumbent on the stalks of the other, and cross each
+other, much after the manner express'd in the second Figure of the 22.
+_Scheme_, by which means every of those little hooked _fibres_ of the
+leaved stalk get between the naked stalks, and the stalks being full of
+knots, and a prety way dis-join'd, so as that the _fibres_ can easily get
+between them, the two parts are so closely and admirably woven together,
+that it is able to impede, for the greatest part, the transcursion of the
+Air; and though they are so exceeding small, as that the thickness of one
+of these stalks amounts not to a 500. part of an Inch, yet do they compose
+so strong a texture, as, notwithstanding the exceeding quick and violent
+beating of them against the Air, by the strength of the Birds wing, they
+firmly hold together. And it argues an admirable providence of Nature in
+the contrivance and fabrick of them; for their texture is such, that though
+by any external injury the parts of them are violently dis-joyn'd, so as
+that the leaves and stalks touch not one another, and consequently several
+of these rents would impede the Bird's flying; yet, for the most part, of
+themselves they readily re-join and re-contex themselves, and are easily by
+the Birds stroking the Feather, or drawing it through its Bill, all of them
+settled and woven into their former and natural posture; for there are such
+an infinite company of those small _fibres_ in the under side of the
+leaves, and most of them have such little crooks at their ends, that they
+readily catch and hold the stalks they touch.
+
+From which strange contexture, it seems rational to suppose that there is a
+certain kind of mesh or hole so small, that the Air will not very easily
+pass through it, as I hinted also in the sixth Observation about small
+Glass Canes, for otherwise it seems probable, that Nature would have drawn
+over some kind of thin film which should have covered all those almost
+square meshes or holes, there seeming through the _Microscope_ to be more
+then half of the surface of the Feather which is open and visibly pervious;
+which conjecture will yet seem more probable from the texture of the
+brushie wings of the _Tinea argentea_, or white Feather wing'd moth, which
+I shall anone describe. But Nature, that knows best its own laws, and the
+several properties of bodies, knows also best how to adapt and fit them to
+her designed ends, and whoso would know those properties, must endeavour to
+trace Nature in its working, and to see what course she observes. And this
+I suppose will be no inconsiderable advantage which the _Schematisms_ and
+Structures of Animate bodies will afford the diligent enquirer, namely,
+most sure and excellent instructions, both as to the practical part of
+_Mechanicks_ and to the _Theory_ and knowledge of the nature of the bodies
+and motions.
+
+       *       *       *       *       *
+
+
+Observ. XXXVI. _Of _Peacoks_, _Ducks_, and other _Feathers_ of   changeable
+colours._
+
+The parts of the Feathers of this glorious Bird appear, through the
+_Microscope_, no less gaudy then do the whole Feathers; for, as to the
+naked eye 'tis evident that the stem or quill of each Feather in the tail
+sends out multitudes of _Lateral_ branches, such as AB in the third Figure
+of the 22. _Scheme_ represents a small part of about 1/32 part of an Inch
+long, and each of the _lateral_ branches emit multitudes of little sprigs,
+threads or hairs on either side of them, such as CD, CD, CD, so each of
+those threads in the _Microscope_ appears a large long body, consisting of
+a multitude of bright reflecting parts, whose Figure 'tis no easie matter
+to determine, as he that examines it shall find; for every new position of
+it to the light makes it perfectly seem of another form and shape, and
+nothing what it appear'd a little before; nay, it appear'd very differing
+ofttimes from so seemingly inconsiderable a circumstance, that the
+interposing of ones hand between the light and it, makes a very great
+change, and the opening or shutting a Casement and the like, very much
+diversifies the appearance. And though, by examining the form of it very
+many ways, which would be tedious here to enumerate, I suppose I have
+discover'd the true Figure of it, yet oftentimes, upon looking on it in
+another posture, I have almost thought my former observations deficient,
+though indeed, upon further examination, I have found even those also to
+confirm them.
+
+These threads therefore I find to be a _congeries_ of small _Laminae_ or
+plates, as eeeee, &c. each of them shap'd much like this of abcd, in the
+fourth _Figure_, the part ac being a ridge, prominency, or stem, and b and
+d the corners of two small thin Plates that grow unto the small stalk in
+the middle, so that they make a kind of little feather; each of these
+Plates lie one close to another, almost like a company of sloping ridge or
+gutter Tyles; they grow on each side of the stalk opposite to one another,
+by two and two, from top to bottom, in the manner express'd in the fifth
+Figure, the tops of the lower covering the roots of the next above them;
+the under side of each of these laminated bodies, is of a very dark and
+opacous substance, and suffers very few Rays to be trajected, but reflects
+them all toward that side from whence they come, much like the foil of a
+Looking-glass; but their upper sides seem to me to consist of a multitude
+of thin plated bodies, which are exceeding thin, and lie very close
+together, and thereby, like mother of Pearl shells, do not onely reflect a
+very brisk light, but tinge that light in a most curious manner; and by
+means of various positions, in respect of the light, they reflect back now
+one colour, and then another, and those most vividly.
+
+Now, that these colours are onely _fantastical_ ones, that is, such as
+arise immediately from the refractions of the light, I found by this, that
+water wetting these colour'd parts, destroy'd their colours, which seem'd
+to proceed from the alteration of the reflection and refraction. Now,
+though I was not able to see those hairs at all transparent by a common
+light, yet by looking on them against the Sun, I found them to be ting'd
+with a darkish red colour, nothing a-kin to the curious and lovely greens
+and blues they exhibited.
+
+What the reason of colour seems to be in such thin plated bodies, I have
+elsewhere shewn. But how water cast upon those threads destroys their
+colours, I suppose to be perform'd thus; The water falling upon these
+plated bodies from its having a greater congruity to Feathers then the Air,
+insinuates it self between those Plates, and so extrudes the strong
+reflecting Air, whence both these parts grow more transparent, as the
+_Microscope_ informs, and colourless also, at best retaining a very faint
+and dull colour. But this wet being wasted away by the continual
+evaporations and steams that pass through them from the Peacock, whil'st
+that Bird is yet alive, the colours again appear in their former luster,
+the _interstitia_ of these Plates being fill'd with the strongly reflecting
+Air.
+
+The beauteous and vivid colours of the Feathers of this Bird, being found
+to proceed from the curious and exceeding smalness and fineness of the
+reflecting parts, we have here the reason given us of all those gauderies
+in the apparel of other Birds also, and how they come to exceed the colours
+of all other kinds of Animals, besides Insects; for since (as we here, and
+elsewhere also shew) the vividness of a colour, depends upon the fineness
+and transparency of the reflecting and refracting parts; and since our
+_Microscope_ discovers to us, that the component parts of feathers are
+such, and that the hairs of Animals are otherwise; and since we find also
+by the Experiment of that Noble and most Excellent Person I formerly named;
+that the difference between Silk and Flax, as to its colour, is nothing
+else (for Flax reduc'd to a very great fineness of parts, both white and
+colour'd, appears as white and as vivid as any Silk, but loses that
+brightness and its Silken aspect as soon as it is twisted into thread, by
+reason that the component parts, though very small and fine, are yet
+pliable flakes, and not cylinders, and thence, by twisting, become united
+into one opacous body, whereas the threads of Silk and Feathers retain
+their lustre, by preserving their cylindrical form intire without mixing;
+so that each reflected and refracted beam that composes the gloss of Silk,
+preserves its own property of modulating the light intire); And since we
+find the same confirm'd by many other Experiments elsewhere mentioned, I
+think we may safely conclude this for an Axiome, that wheresoever we meet
+with transparent bodies, spun out into very fine parts, either cleer, or
+any ways ting'd, the colours resulting from such a _composition_ must
+necessarily be very glorious, vivid, and cleer, like those of Silk and
+Feathers. This may perhaps hint some usefull way of making other bodies,
+besides Silk, be susceptible of bright tinctures, but of this onely by the
+by.
+
+The changeable colour'd Feathers also of Ducks, and several other Birds, I
+have found by examination with my _Microscope_, to proceed from much the
+same causes and textures.
+
+       *       *       *       *       *
+
+
+Observ. XXXVII. _Of the Feet of _Flies_, and several other _Insects_._
+
+The foot of a Fly (delineated in the first _Figure_ of the 23. _Scheme_,
+which represents three joints, the two Tallons, and the two Pattens in a
+flat posture; and in the second _Figure_ of the same _Scheme_, which
+represents onely one joint, the Tallons and Pattens in another posture) is
+of a most admirable and curious contrivance, for by this the Flies are
+inabled to walk against the sides of Glass, perpendicularly upwards, and to
+contain themselves in that posture as long as they please; nay, to walk and
+suspend themselves against the under surface of many bodies, as the ceiling
+of a room, or the like, and this with as great a seeming facility and
+firmness, as if they were a kind of _Antipodes_, and had a _tendency_
+upwards, as we are sure they have the contrary, which they also evidently
+discover, in that they cannot make themselves so light, as to stick or
+suspend themselves on the under surface of a Glass well polish'd and
+cleans'd; their suspension therefore is wholly to be ascrib'd to some
+Mechanical contrivance in their feet; which, what it is, we shall in brief
+explain, by shewing, that its Mechanism consists principally in two parts,
+that is, first its two Claws, or Tallons, and secondly, two Palms, Pattens,
+or Soles.
+
+The two Tallons are very large, in proportion to the foot, and handsomly
+shap'd in the manner describ'd in the _Figures_, by AB, and AC, the bigger
+part of them from A to _dd_, is all hairy, or brisled, but toward the top,
+at C and B smooth, the tops or points, which seem very sharp turning
+downwards and inwards, are each of them mov'd on a joint at A, by which the
+Fly is able to open or shut them at pleasure, so that the points B and C
+being entered in any pores, and the Fly endeavouring to shut them, the
+Claws not onely draw one against another, and so fasten each other, but
+they draw the whole foot, GGADD forward, so that on a soft footing, the
+tenters or points GGGG, (whereof a Fly has about ten in each foot, to wit,
+two in every joint) run into the pores, if they find any, or at least make
+their way; and this is sensible to the naked eye, in the feet of a
+_Chafer_, which, if he be suffer'd to creep over the hand, or any other
+part of the skin of ones body, does make his steps as sensible to the touch
+as the sight.
+
+But this contrivance, as it often fails the _Chafer_, when he walks on hard
+and close bodies, so would it also our Fly, though he be a much lesser, and
+nimbler creature, and therefore Nature has furnish'd his foot with another
+_additament_ much more curious and admirable, and that is, with a couple of
+Palms, Pattens or Soles DD, the structure of which is this:
+
+From the bottom or under part of the last joint of his foot, K, arise two
+small thin plated horny substances, each consisting of two flat pieces, DD,
+which seem to be flexible, like the covers of a Book, about FF, by which
+means, the plains of the two sides EE, do not always lie in the same plain,
+but may be sometimes shut closer, and so each of them may take a little
+hold themselves on a body; but that is not all, for the under sides of
+these Soles are all beset with small brisles, or tenters, like the Wire
+teeth of a Card used for working Wool, the points of all which tend
+forwards, hence the two Tallons drawing the feet forwards, as I before
+hinted, and these being applied to the surface of the body with all the
+points looking the contrary way, that is, forwards and outwards, if there
+be any irregularity or yielding in the surface of the body, the Fly
+suspends it self very firmly and easily, without the access or need of any
+such Sponges fill'd with an imaginary _gluten_, as many have, for want of
+good Glasses, perhaps, or a troublesome and diligent examination, suppos'd.
+
+Now, that the Fly is able to walk on Glass, proceeds partly from some
+ruggedness of the surface: and chiefly from a kind of tarnish, or dirty
+smoaky substance, which adheres to the surface of that very hard body; and
+though the pointed parts cannot penetrate the substance of Glass, yet may
+they find pores enough in the tarnish, or at least make them.
+
+This Structure I somewhat the more diligently survey'd, because I could not
+well comprehend, how, if there were such a glutinous matter in those
+supposed Sponges, as most (that have observ'd that Object in a
+_Microscope_) have hitherto believ'd, how, I say, the Fly could so readily
+unglew and loosen its feet: and, because I have not found any other
+creature to have a contrivance any ways like it, and chiefly, that we might
+not be cast upon unintelligible explications of the _Phaenomena_ of Nature,
+at least others then the true ones, where our senses were able to furnish
+us with an intelligible, rationall and true one.
+
+Somewhat a like contrivance to this of Flies shall we find in most other
+Animals, such as all kinds of Flies and case-wing'd creatures; nay, in a
+Flea, an Animal abundantly smaller then this Fly. Other creatures, as
+Mites, the Land-Crab, &c. have onely one small very sharp Tallon at the end
+of each of their legs, which all drawing towards the center or middle of
+their body, inable these exceeding light bodies to suspend and fasten
+themselves to almost any surface.
+
+Which how they are able to do, will not seem strange, if we consider,
+first, how little body there is in one of these creatures compar'd to their
+superficies, or outside, their thickness, perhaps, oftentimes, not
+amounting to the hundredth part of an Inch: Next, the strength and agility
+of these creatures compar'd to their bulk, being, proportionable to their
+bulk, perhaps, an hundred times stronger then an Horse or Man. And thirdly,
+if we consider that Nature does always appropriate the instruments, so as
+they are the most fit and convenient to perform their offices, and the most
+simple and plain that possibly can be; this we may see further verify'd
+also in the foot of a Louse which is very much differing from those I have
+been describing, but more convenient and necessary for the place of its
+habitation, each of his leggs being footed with a couple of small claws
+which he can open or shut at pleasure, shap'd almost like the claws of a
+Lobster or Crab, but with appropriated contrivances for his peculiar life,
+which being to move its body to and fro upon the hairs of the creature it
+inhabits, Nature has furnish'd one of its claws with joints, almost like
+the joints of a man's fingers, so as thereby it is able to encompass or
+grasp a hair as firmly as a man can a stick or rope.
+
+Nor, is there a less admirable and wonderfull _Mechanism_ in the foot of a
+Spider, whereby he is able to spin, weave, and climb, or run on his curious
+transparent clew, of which I shall say more in the description of that
+Animal.
+
+And to conclude, we shall in all things find, that Nature does not onely
+work Mechanically, but by such excellent and most compendious, as well as
+stupendious contrivances, that it were impossible for all the reason in the
+world to find out any contrivance to do the same thing that should have
+more convenient properties. And can any be so sottish, as to think all
+those things the productions of chance? Certainly, either their
+Ratiocination must be extremely depraved, or they did never attentively
+consider and contemplate the Works of the Al-mighty.
+
+       *       *       *       *       *
+
+
+Observ. XXXVIII. _Of the Structure and motion of the Wings of _Flies_._
+
+The Wings of all kinds of Insects, are, for the most part, very beautifull
+Objects, and afford no less pleasing an Object to the mind to speculate
+upon, then to the eye to behold. This of the blue Fly, among the rest,
+wants not its peculiar ornaments and contrivances; it grows out of the
+_Thorax_, or middle part of the body of a Fly, and is seated a little
+beyond the center of gravity in the body towards the head, but that
+_Excentricly_ is curiously balanc'd; first, by the expanded _Area_ of the
+wings which lies all more backwards then the root, by the motion of them,
+whereby the center of their vibration is much more backwards towards the
+tail of the Fly then the root of the wing is. What the vibrative motion of
+the wings is, and after what manner they are moved, I have endeavoured by
+many trials to find out: And first for the manner of their motion, I
+endeavoured to observe several of those kind of small Spinning Flies, which
+will naturally suspend themselves, as it were, pois'd and steady in one
+place of the air, without rising or falling, or moving forwards or
+backwards; for by looking down on those, I could by a kind of faint shadow,
+perceive the utmost extremes of the vibrative motion of their wings, which
+shadow, whil'st they so endeavoured to suspend themselves, was not very
+long, but when they endeavour'd to flie forwards, it was somewhat longer;
+next, I tried it, by fixing the leggs of a Fly upon the top of the stalk of
+a feather, with Glew, Wax, &c. and then making it endeavour to flie away;
+for being thereby able to view it in any posture, I collected that the
+motion of the wing was after this manner. The extreme limits of the
+vibrations were usually somewhat about the length of the body distant from
+one another, oftentimes shorter, and sometimes also longer; that the
+formost limit was usually a little above the back, and the hinder somwhat
+beneath the belly; between which two limits, if one may ghess by the sound,
+the wing seem'd to be mov'd forwards and backwards with an equal velocity:
+And if one may (from the shadow or faint representation the wings afforded,
+and from the consideration of the nature of the thing) ghess at the posture
+or manner of the wings moving between them, it seem'd to be this: The wing
+being suppos'd placed in the upmost limit, seems to be put so that the
+plain of it lies almost _horizontal_, but onely the forepart does dip a
+little, or is somewhat more deprest; in this position is the wing vibrated
+or mov'd to the lower limit, being almost arrived at the lower limit, the
+hinder part of the wing moving somewhat faster then the former, the _Area_,
+of the wing begins to dip behind, and in that posture seems it to be mov'd
+to the upper limit back again, and thence back again in the first posture,
+the former part of the _Area_ dipping again, as it is moved downwards by
+means of the quicker motion of the main stem which terminates or edges the
+forepart of the wing. And these vibrations or motions to and fro between
+the two limits seem so swift, that 'tis very probable (from the sound it
+affords, if it be compar'd with the vibration of a musical string, tun'd
+unison to it) it makes many hundreds, if not some thousands of vibrations
+in a second minute of time. And, if we may be allow'd to ghess by the
+sound, the wing of a Bee is yet more swift, for the tone is much more
+acute, and that, in all likelihood, proceeds from the exceeding swift
+beating of the air by the small wing. And it seems the more likely too,
+because the wing of a Bee is less in proportion to its body, then the other
+wing to the body of a Fly; so that for ought I know, it may be one of the
+quickest vibrating _spontaneous_ motions of any in the world; and though
+perhaps there may be many Flies in other places that afford a yet more
+shrill note with their wings, yet 'tis most probable that the quickest
+vibrating _spontaneous_ motion is to be found in the wing of some creature.
+Now, if we consider the exceeding quickness of these Animal spirits that
+must cause these motions, we cannot chuse but admire the exceeding
+vividness of the governing faculty or _Anima_ of the Insect, which is able
+to dispose and regulate so the the motive faculties, as to cause every
+peculiar organ, not onely to move or act so quick, but to do it also so
+regularly.
+
+Whil'st I was examining and considering the curious _Mechanism_ of the
+wings, I observ'd that under the wings of most kind of Flies, Bees, &c.
+there were plac'd certain _pendulums_ or extended drops (as I may so call
+them from their resembling motion and figure) for they much resembled a
+long hanging drop of some transparent viscous liquor; and I observed them
+constantly to move just before the wings of the Fly began to move, so that
+at the first sight I could not but ghess, that there was some excellent
+use, as to the regulation of the motion of the wing, and did phancy, that
+it might be something like the handle of a Cock, which by vibrating to and
+fro, might, as 'twere, open and shut the Cock, and thereby give a passage
+to the determinate influences into the Muscles; afterwards, upon some other
+trials, I suppos'd that they might be for some use in respiration, which
+for many reasons I suppose those Animals to use, and, me thought, it was
+not very improbable, but that they might have convenient passages under the
+wings for the emitting, at least, of the air, if not admitting, as in the
+gills of Fishes is most evident; or, perhaps, this _Pendulum_ might be
+somewhat like the staff to a Pump, whereby these creatures might exercise
+their _Analogous_ lungs, and not only draw in, but force out, the air they
+live by: but these were but conjectures, and upon further examination
+seem'd less probable.
+
+The fabrick of the wing, as it appears through a moderately magnifying
+_Microscope_, seems to be a body consisting of two parts, as is visible in
+the 4. _Figure_ of the 23. _Scheme_; and by the 2. _Figure_ of the 26.
+_Scheme_; the one is a quilly or finny substance, consisting of several
+long, slender and variously bended quills or wires, something resembling
+the veins of leaves; these are, as 'twere, the finns or quills which
+stiffen the whole _Area_, and keep the other part distended, which is a
+very thin transparent skin or membrane variously folded, and platted, but
+not very regularly, and is besides exceeding thickly bestuck with
+innumerable small bristles, which are onely perceptible by the bigger
+magnifying _Microscope_, and not with that neither, but with a very
+convenient augmentation of sky-light projected on the Object with a burning
+Glass, as I have elsewhere shew'd, or by looking through it against the
+light.
+
+In steed of these small hairs, in several other Flies, there are infinite
+of small Feathers, which cover both the under and upper sides of this thin
+film as in almost all the sorts of Butterflies and Moths: and those small
+parts are not onely shap'd very much like the feathers of Birds, but like
+those variegated with all the variety of curious bright and vivid colours
+imaginable; and those feathers are likewise so admirably and delicately
+rang'd, as to compose very fine flourishings and ornamental paintings, like
+_Turkie_ and _Persian_ Carpets, but of far more surpassing beauty, as is
+evident enough to the naked eye, in the painted wings of Butterflies, but
+much more through an ordinary _Microscope_.
+
+Intermingled likewise with these hairs, may be perceived multitudes of
+little pits, or black spots, in the exended membrane, which seem to be the
+root of the hairs that grow on the other side; these two bodies seem
+dispers'd over the whole surface of the wing.
+
+The hairs are best perceiv'd, by looking through it against the light, or,
+by laying the wing upon a very white piece of Paper, in a convenient light,
+for thereby every little hair most manifestly appears; a _Specimen_ of
+which you may observe drawn in the fourth _Figure_ of the 23. _Scheme_, AB,
+CD, EF whereof represent some parts of the bones or quills of the wing,
+each of which you may perceive to be cover'd over with a multitude of
+scales, or bristles, the former AB, is the biggest stem of all the wing,
+and may be properly enough call'd the cut-air, it being that which
+terminates and stiffens the formost edge of the wing; the fore-edge of this
+is arm'd with a multitude of little brisles, or Tenter-hooks, in some
+standing regular and in order, in others not; all the points of which are
+directed from the body towards the tip of the wing, nor is this edge onely
+thus fring'd, but even all the whole edge of the wing is covered with a
+small fringe, consisting of short and more slender brisles.
+
+This Subject, had I time, would afford excellent matter for the
+contemplation of the nature of wings and of flying, but, because I may,
+perhaps, get a more convenient time to prosecute that speculation, and
+recollect several Observations that I have made of that particular. I shall
+at present proceed to
+
+       *       *       *       *       *
+
+
+Observ. XXXIX. _Of the Eyes and Head of a _Grey drone-Fly_,
+and of several other creatures._
+
+I took a large grey _Drone-Fly_, that had a large head, but a small and
+slender body in proportion to it, and cutting off its head, I fix'd it with
+the forepart or face upwards upon my Object Plate (this I made choice of
+rather then the head of a great blue Fly, because my enquiry being now
+about the eyes, I found this Fly to have, first the biggest clusters of
+eyes in proportion to his head, of any small kind of Fly that I have yet
+seen, it being somewhat inclining towards the make of the large
+_Dragon-Flies_. Next, because there is a greater variety in the knobs or
+balls of each cluster, then is of any small Fly.) Then examining it
+according to my usual manner, by varying the degrees of light, and altering
+its position to each kinde of light, I drew that representation of it which
+is delineated in the 24. _Scheme_, and found these things to be as plain
+and evident, as notable and pleasant.
+
+_First_, that the greatest part of the face, nay, of the head, was nothing
+else but two large and _protuberant_ bunches, or _prominent_ parts, ABCDEA,
+the surface of each of which was all cover'd over, or shap'd into a
+multitude of small _Hemispheres_, plac'd in a _triagonal_ order, that being
+the closest and most compacted, and in that order, rang'd over the whole
+surface of the eye in very lovely rows, between each of which, as is
+necessary, were left long and regular trenches, the bottoms of every of
+which, were perfectly intire and not at all perforated or drill'd through,
+which I most certainly was assured of, by the regularly reflected Image of
+certain Objects which I mov'd to and fro between the head and the light.
+And by examining the _Cornea_ or outward skin, after I had stript it off
+from the several substances that lay within it, and by looking both upon
+the inside and against the light.
+
+_Next_, that of those multitudes of _Hemispheres_, there were observable
+two degrees of bigness, the half of them that were lowermost, and look'd
+toward the ground or their own leggs, namely, CDE, CDE being a pretty deal
+smaller then the other, namely, ABCE, ABCE, that look'd upward, and
+side-ways, or foreright, and backward, which variety I have not found in
+any other small Fly.
+
+_Thirdly_, that every one of these _Hemispheres_, as they seem'd to be
+pretty neer the true shape of a _Hemisphere_, so was the surface exceeding
+smooth and regular, reflecting as exact, regular, and perfect an Image of
+any Object from the surface of them, as a small Ball of Quick-silver of
+that bigness would do, but nothing neer so vivid, the reflection from these
+being very languid, much like the reflection from the outside of Water,
+Glass, Crystal, &c. In so much that in each of these _Hemispheres_, I have
+been able to discover a Land-scape of those things which lay before my
+window, one thing of which was a large Tree, whose trunk and top I could
+plainly discover, as I could also the parts of my window, and my hand and
+fingers, if I held it between the Window and the Object; a small draught of
+nineteen of which, as they appear'd in the bigger Magnifying-glass to
+reflect the Image of the two windows of my Chamber, are delineated in the
+third _Figure_ of the 23. _Scheme_.
+
+_Fourthly_, that these rows were so dispos'd, that there was no quarter
+visible from his head that there was not some of these _Hemispheres_
+directed against, so that a Fly may be truly said to have _an eye every
+way_, and to be really _circumspect_. And it was further observable, that
+that way where the trunk of his body did hinder his prospect backward,
+these _protuberances_ were elevated, as it were, above the plain of his
+shoulders and back, so that he was able to see backwards also over his
+back.
+
+_Fifthly_, in living Flies, I have observ'd, that when any small mote or
+dust, which flies up and down the air, chances to light upon any part of
+these knobs, as it is sure to stick firmly to it and not fall, though
+through the _Microscope_ it appears like a large stone or stick (which one
+would admire, especially since it is no ways probable that there is any wet
+or glutinous matter upon these _Hemispheres_, but I hope I shall render the
+reason in another place) so the Fly presently makes use of his two
+fore-feet in stead of eye-lids, with which, as with two Brooms or Brushes,
+they being all bestuck with Brisles, he often sweeps or brushes off what
+ever hinders the prospect of any of his _Hemispheres_, and then, to free
+his leggs from that dirt, he rubs them one against another, the pointed
+Brisles or Tenters of which looking both one way, the rubbing of them to
+and fro one against another, does cleanse them in the same manner as I have
+observ'd those that Card Wool, to cleanse their Cards, by placing their
+Cards, so as the teeth of both look the same way, and then rubbing them one
+against another. In the very same manner do they brush and cleanse their
+bodies and wings, as I shall by and by shew; other creatures have other
+contrivances for the cleansing and cleering their eyes.
+
+_Sixthly_ that the number of the _Pearls_ or _Hemispheres_ in the clusters
+of this Fly, was neer 14000. which I judged by numbering certain rows of
+them several ways, and casting up the whole content, accounting each
+cluster to contain about seven thousand Pearls, three thousand of which
+were of a size, and consequently the rows not so thick, and the foure
+thousand I accounted to be the number of the smaller Pearls next the feet
+and _proboscis_. Other Animals I observ'd to have yet a greater number, as
+the _Dragon-Fly_ or _Adderbolt_: And others to have a much less company, as
+an _Ant_, &c. and several other small Flies and Insects.
+
+_Seventhly_, that the order of these eies or _Hemispheres_ was altogether
+curious and admirable, they being plac'd in all kind of Flies, and _aerial_
+animals, in a most curious and regular ordination of triangular rows, in
+which order they are rang'd the neerest together that possibly they can,
+and consequently leave the least pits or trenches between them. But in
+_Shrimps_, _Crawfishes_, _Lobsters_, and such kinds of _Crustaceous_ water
+Animals, I have yet observ'd them rang'd in a quadrangular order, the rows
+cutting each other at right angles, which as it admits of a less number of
+Pearls in equal surfaces; so have those creatures a recompence made them,
+by having their eyes a little movable in their heads, which the other
+altogether want. So infinitely wise and provident do we find all the
+Dispensations in Nature, that certainly _Epicurus_, and his followers, must
+very little have consider'd them, who ascrib'd those things to the
+production of chance, that wil, to a more attentive considerer, appear the
+products of the highest Wisdom and Providence.
+
+Upon the Anatomy or Dissection of the Head, I observ'd these particulars:
+
+First, that this outward skin, like the _Cornea_ of the eyes of the greater
+Animals, was both flexible and transparent, and seem'd, through the
+_Microscope_ perfectly to resemble the very substance of the _Cornea_ of a
+man's eye; for having cut out the cluster, and remov'd the dark and
+_mucous_ stuff that is subjacent to it, I could see it transparent like a
+thin piece of skin, having as many cavities in the inside of it, and rang'd
+in the same order as it had _protuberances_ on the outside, and this
+propriety, I found the same in all the Animals that had it, whether Flies
+or Shell-Fish.
+
+Secondly, I found that all Animals that I have observ'd with those kind of
+eyes; have within this _Cornea_, a certain cleer liquor or juice, though in
+a very little quantity, and,
+
+I observ'd thirdly, that within that cleer liquor, they had a kind of dark
+_mucous_ lining, which was all spread round within the cavity of the
+clutter, and seem'd very neer adjoining to it, the colour of which, in some
+Flies, was grey; in others, black, in others red; in others, of a mix'd
+colour; in others, spotted; and that the whole clusters, when look'd on
+whilst the Animal was living, or but newly kill'd, appear'd of the same
+colour that this coat (as I may so call it) appear'd of, when that outward
+skin, or _Cornea_, was remov'd.
+
+Fourthly, that the rest of the capacity of the clusters was in some, as in
+Dragon Flies, &c. hollow, or empty; in others fill'd with some kind of
+substance; in blue Flies, with a reddish musculous substance, with _fibres_
+tending from the center or bottom outwards; and divers other, with various
+and differing kinds of substances.
+
+That this curious contrivance is the organ of sight to all those various
+_Crustaceous_ Animals, which are furnish'd with it, I think we need not
+doubt, if we consider but the several congruities it has with the eyes of
+greater creatures.
+
+As first, that it is furnish'd with a _Cornea_, with a _transparent
+humour_, and with a _uvea_ or _retina_, that the Figure of each of the
+small _Hemispheres_ are very _Spherical_, exactly polish'd, and most vivid,
+lively and plump, when the Animal is living, as in greater Animals, and in
+like manner dull, flaccid, and irregular, or shrunk, when the Animal is
+dead.
+
+Next, that those creatures that are furnish'd with it, have no other organs
+that have any resemblance to the known eyes of other creatures.
+
+Thirdly, that those which they call the eyes of Crabs, Lobsters, Shrimps,
+and the like, and are really so, are _Hemispher'd_, almost in the same
+manner as these of Flies are. And that they really are so, I have very
+often try'd, by cutting off these little movable knobs, and putting the
+creature again into the water, that it would swim to and fro, and move up
+and down as well as before, but would often hit it self against the rocks
+or stones; and though I put my hand just before its head, it would not at
+all start or fly back till I touch'd it, whereas whil'st those were
+remaining, it would start back, and avoid my hand or a stick at a good
+distance before it touch'd it. And if in _crustaceous_ Sea-animals, then it
+seems very probable also, that these knobs are the eyes in _crustaceous_
+Insects, which are also of the same kind, onely in a higher and more active
+Element; this the conformity or congruity of many other parts common to
+either of them, will strongly argue, their _crustaceous_ armour, their
+number of leggs, which are six, beside the two great claws, which answer to
+the wings in Insects; and in all kind of Spiders, as also in many other
+Insects that want wings, we shall find the compleat number of them, and not
+onely the number, but the very shape, figure, joints, and claws of Lobsters
+and Crabs, as is evident in Scorpions and Spiders, as is visible in the
+second _Figure_ of the 31. _Scheme_, and in the little Mite-worm, which I
+call a Land-crab, describ'd in the second Figure of the 33. _Scheme_, but
+in their manner of generation being oviparous, &c. And it were very worthy
+observation, whether there be not some kinds of transformation and
+metamorphosis in the several states of _crustaceous_ water-animals, as
+there is in several sorts of Insects; for if such could be met with, the
+progress of the variations would be much more conspicuous in those larger
+Animals, then they can be in any kind of Insects our colder Climate
+affords.
+
+These being their eyes, it affords us a very pretty Speculation to
+contemplate their manner of vision, which, as it is very differing from
+that of _biocular_ Animals, so is it not less admirable.
+
+That each of these Pearls or _Hemispheres_ is a perfect eye, I think we
+need not doubt, if we consider onely the outside or figure of any one of
+them, for they being each of them cover'd with a transparent protuberant
+_Cornea_, and containing a liquor within them, resembling the watry or
+glassie humours of the eye, must necessarily refract all the parallel Rays
+that fall on them out of the air, into a point not farr distant within
+them, where (in all probability) the _Retina_ of the eye is placed, and
+that opacous, dark, and mucous inward coat that (I formerly shew'd) I found
+to subtend the concave part of the cluster is very likely to be that
+_tunicle_ or coat, it appearing through the _Microscope_ to be plac'd a
+little more than a Diameter of those Pearls below or within the _tunica
+cornea_. And if so, then is there in all probability, a little Picture or
+Image of the objects without, painted or made at the bottom of the _Retina_
+against every one of those Pearls, so that there are as many impressions on
+the _Retina_ or opacous skin, as there are Pearls or _Hemispheres_ on the
+cluster. But because it is impossible for any protuberant surface
+whatsoever, whether _sphaerial_ or other, so to refract the Rays that come
+from farr remote _lateral_ points of any Object as to collect them again,
+and unite them each in a distinct point, and that onely those Rays which
+come from some point that lies in the _Axis_ of the Figure produc'd, are so
+accurately refracted to one and the same point again, and that the
+_lateral_ Rays, the further they are remov'd, the more imperfect is their
+refracted confluence; It follows therefore, that onely the Picture of those
+parts of the external objects that lie in, or neer, the _Axis_ of each
+_Hemisphere_, are discernably painted or made on the _Retina_ of each
+_Hemisphere_, and that therefore each of them can distinctly sensate or see
+onely those parts which are very neer perpendicularly oppos'd to it, or lie
+in or neer its optick _Axis_. Now, though there may be by each of these
+eye-pearls, a representation to the Animal of a whole _Hemisphere_ in the
+same manner as in a man's eye there is a picture or sensation in the
+_Retina_ of all the objects lying almost in an _Hemisphere_; yet, as in a
+man's eye also, there are but some very few points which liyng in, or neer,
+the optick _Axis_ are distinctly discern'd: So there may be multitudes of
+Pictures made of an Object in the several Pearls, and yet but one, or some
+very few that are distinct; The representation of any object that is made
+in any other Pearl, but that which is directly, or very neer directly,
+oppos'd, being altogether confus'd and unable to produce a distinct vision.
+
+So that we see, that though it has pleas'd the All-wise Creator, to indue
+this creature with such multitudes of eyes, yet has he not indued it with
+the faculty of seeing more then another creature; for whereas this cannot
+move his head, at least can move it very little, without moving his whole
+body, _biocular_ creatures can in an instant (or _the twinkling of an eye_,
+which, being very quick, is vulgarly used in the same signification) move
+their eyes so as to direct the optick _Axis_ to any point; nor is it
+probable, that they are able to see attentively at one time more then one
+Physical point; for though there be a distinct Image made in every eye, yet
+'tis very likely, that the observing faculty is only imploy'd about some
+one object for which they have most concern.
+
+Now, as we accurately distinguish the site or position of an Object by the
+motion of the Muscles of the eye requisite to put the optick Line in a
+direct position, and confusedly by the position of the imperfect Picture of
+the object at the bottom of the eye; so are these _crustaceous_ creatures
+able to judge confusedly of the position of objects by the Picture or
+impression made at the bottom of the opposite Pearl, and distinctly by the
+removal of the attentive or observing faculty, from one Pearl to another,
+but what this faculty is, as it requires another place, so a much deeper
+speculation. Now, because it were impossible, even with this multitude of
+eye-balls, to see any object distinct (for as I hinted before, onely those
+parts that lay in, or very neer, the optick Lines could be so) the
+Infinitely wise Creator has not left the creature without a power of moving
+the head a little in _Aerial crustaceous_ animals, and the very eyes also
+in _crustaceous_ Sea-animals; so that by these means they are inabled to
+direct some optick line or other against any object, and by that means they
+have the visive faculty as compleat as any Animal that can move its eyes.
+
+Distances of Objects also, 'tis very likely they distinguish, partly by the
+consonant impressions made in some two convenient Pearls, one in each
+cluster; for, according as those congruous impressions affect, two Pearls
+neerer approach'd to each other, the neerer is the Object, and the farther
+they are distant, the more distant is the Object: partly also by the
+alteration of each Pearl, requisite to make the Sensation or Picture
+perfect; for 'tis impossible that the Pictures of two Objects, variously
+distant, can be perfectly painted, or made on the same _Retina_ or bottom
+of the eye not altered, as will be very evident to any one that shall
+attentively consider the nature of refraction. Now, whether this alteration
+may be in the Figure of the _Cornea_, in the motion of access or recess of
+the _Retina_ towards the _Cornea_, or in the alteration of a crustaline
+humour, if such there be, I pretend not to determine; though I think we
+need not doubt, but that there may be as much curiosity of contrivance and
+structure in every one of these Pearls, as in the eye of a Whale or
+Elephant, and the almighty's _Fiat_ could as easily cause the existence of
+the one as the other; and as one day and a thousand years are the same with
+him, so may one eye and ten thousand.
+
+This we may be sure of, that the filaments or sensative parts of the
+_Retina_ must be most exceedingly curious and minute, since the whole
+Picture it self is such; what must needs the component parts be of that
+_Retina_, which distinguishes the part of an object's Picture that must be
+many millions of millions less then that in a man's eye? And how exceeding
+curious and subtile must the component parts of the _medium_ that conveys
+light be, when we find the instrument made for its reception or refraction
+to be so exceedingly small? we may, I think, from this speculation be
+sufficiently discouraged from hoping to discover by any optick or other
+instrument the determinate bulk of the parts of the _medium_ that conveys
+the pulse of light, since we find that there is not less accurateness shewn
+in the Figure and polish of those exceedingly minute lenticular surfaces,
+then in those more large and conspicuous surfaces of our own eyes. And yet
+can I not doubt, but that there is a determinate bulk of those parts, since
+I find them unable to enter between the parts of Mercury, which being in
+motion, must necessarily have pores, as I shall elsewhere shew, and here
+pass by, as being a digression.
+
+As concerning the horns FF, the feelers or smellers, GG, the _Probascis_
+HH, and I, the hairs and brisles, KK, I shall indeavour to describe in the
+42. _Observation_.
+
+       *       *       *       *       *
+
+
+Observ. XL. _Of the Teeth of a _Snail_._
+
+I have little more to add of the Teeth of a Snail, besides the Picture of
+it, which is represented in the first _Figure_ of the 25. _Scheme_, save
+that his bended body, ABCDEF, which seem'd fashioned very much like a row
+of small teeth, orderly plac'd in the Gums, and looks as if it were divided
+into several smaller and greater black teeth, was nothing but one small
+bended hard bone, which was plac'd in the upper jaw of the mouth of a
+House-Snail, with which I observ'd this very Snail to feed on the leaves of
+a Rose-tree, and to bite out pretty large and half round bits, not unlike
+the Figure of a (C) nor very much differing from it in bigness, the upper
+part ABCD of this bone, I found to be much whiter, and to grow out of the
+upper chap of the Snail, GGG, and not to be any thing neer so much creas'd
+as the lower and blacker part of it HIIHKKH which was exactly shap'd like
+teeth, the bone growing thinner, or tapering to an edge towards KKK. It
+seem'd to have nine teeth, or prominent parts IK, IK, IF, &c. which were
+join'd together by the thinner interpos'd parts of the bone. The Animal to
+which these teeth belong, is a very _anomalous_ creature, and seems of a
+kind quite distinct from any other terrestrial Animal or Insect, the
+Anatomy whereof exceedingly differing from what has been hitherto given of
+it I should have inserted, but that it will be more proper in another
+place. I have never met with any kind of Animal whose teeth are all join'd
+in one, save onely that I lately observ'd, that all the teeth of a
+Rhinocerot, which grow on either side of its mouth, are join'd into one
+large bone, the weight of one of which I found to be neer eleven pound
+_Haverdupois_. So that it seems one of the biggest sort of terrestrial
+Animals, as well as one of the smallest, has his teeth thus shap'd.
+
+       *       *       *       *       *
+
+
+Observ. XLI. _Of the Eggs of _Silk-worms_, and other Insects._
+
+The Eggs of Silk-worms (one of which I have describ'd in the second
+_Figure_ of 25. _Scheme_) afford a pretty Object for a _Microscope_ that
+magnifies very much, especially if it be bright weather, and the light of a
+window be cast or collected on it by a deep _Convex-glass_, or Water-ball.
+For then the whole surface of the Shell may be perceiv'd all cover'd over
+with exceeding small pits or cavities with interposed edges, almost in the
+manner of the surface of a Poppy-seed, but that these holes are not an
+hundredth part scarce of their bigness; the Shell, when the young ones were
+hatch'd (which I found an easie thing to do, if the Eggs were kept in a
+warm place) appear'd no thicker in proportion to its bulk, then that of an
+Hen's or Goos's Egg is to its bulk, and all the Shell appear'd very white
+(which seem'd to proceed from its transparency) whence all those pittings
+did almost vanish, so that they could not, without much difficulty, be
+discern'd, the inside of the Shell seem'd to be lin'd also with a kind of
+thin film, not unlike (keeping the proportion to its Shell) that with which
+the shell of an Hen-egg is lin'd; and the shell it self seem'd like common
+Egg-shells; very brittle, and crack'd. In divers other of these Eggs I
+could plainly enough, through the shell, perceive the small Insect lie
+coyled round the edges of the shell. The shape of the Egg it self, the
+Figure pretty well represents (though by default of the Graver it does not
+appear so rounded, and lying above the Paper, as it were, as it ought to
+do) that is, it was for the most part pretty oval end-ways, somewhat like
+an Egg, but the other way it was a little flatted on two opposite sides.
+Divers of these Eggs, as is common to most others, I found to be barren, or
+addle, for they never afforded any young ones. And those I usually found
+much whiter then the other that were prolifick. The Eggs of other kinds of
+Oviparous Insects I have found to be perfectly round every way, like so
+many Globules, of this sort I have observ'd some sorts of Spiders Eggs; and
+chancing the last Summer to inclose a very large and curiously painted
+Butterfly in a Box, intending to examine its gaudery with my _Microscope_,
+I found within a day or two after I inclos'd her, almost all the inner
+surface of the Box cover'd over with an infinite of exactly round Eggs,
+which were stuck very fast to the sides of it, and in so exactly regular
+and close an order, that made me call to mind my _Hypothesis_, which I had
+formerly thought on for the making out of all the regular Figures of Salt,
+which I have elsewhere hinted; for here I found all of them rang'd into a
+most exact _triagonal_ order, much after the manner as the _Hemispheres_
+are place on the eye of a Fly; all which Eggs I found after a little time
+to be hatch'd, and out of them to come a multitude of small Worms, very
+much resembling young Silk-worms, leaving all their thin hollow shells
+behind them, sticking on the Box in their _triagonal_ posture; these I
+found with the _Microscope_ to have much such a substance as the Silk-worms
+Eggs, but could not perceive them pitted. And indeed, there is as great a
+variety in the shape of the Eggs of Oviparous Insects as among those of
+Birds.
+
+Of these Eggs, a large and lusty Fly will at one time lay neer four or five
+hundred, so that the increase of these kind of Insects must needs be very
+prodigious, were they not prey'd on by multitudes of Birds, and destroy'd
+by Frosts and Rains; and hence 'tis those hotter Climates between the
+_Tropicks_ are infested with such multitudes of Locusts, and such other
+Vermine.
+
+       *       *       *       *       *
+
+
+Observ. XLII. _Of a blue _Fly_._
+
+This kind of Fly, whereof a _Microscopical_ Picture is delineated in the
+first _Figure_ of the 26. _Scheme_, is a very beautifull creature, and has
+many things about it very notable; divers of which I have already partly
+describ'd, namely, the feet, wings, eyes, and head, in the preceding
+Observations.
+
+And though the head before describ'd be that of a grey _Drone-Fly_, yet for
+the main it is very agreeable to this. The things wherein they differ most,
+will be easily enough found by the following particulars:
+
+First, the clusters of eyes of this Fly, are very much smaller then those
+of the _Dron-Fly_, in proportion to the head.
+
+And next, all the eyes of each cluster seem'd much of the same bigness one
+with another, not differing as the other, but rang'd in the same
+_triagonal_ order.
+
+Thirdly, between these two clusters, there was a scaly prominent _front_ B,
+which was arm'd and adorn'd with large tapering sharp black brisles, which
+growing out in rows on either side, were so bent toward each other neer the
+top, as to make a kind of arched arbour of Brisles, which almost cover'd
+the former _front_.
+
+Fourthly, at the end of this Arch, about the middle of the face, on a
+prominent part C, grew two small oblong bodies, DD, which through a
+_Microscope_ look'd not unlike the Pendants in Lillies, these seem'd to be
+jointed on to two small parts at C, each of which seem'd again jointed into
+the front.
+
+Fifthly, out of the upper part and outsides of these horns (as I may call
+them, from the Figure they are of, in the 24. _Scheme_, where they are
+marked with FF) there grows a single feather, or brushy Brisle, EE,
+somewhat of the same kind with the tufts of a Gnat, which I have before
+described.
+
+What the use of these kind of horned and tufted bodies should be, I cannot
+well imagine, unless they serve for smelling or hearing, though how they
+are adapted for either, it seems very difficult to describe: they are in
+almost every several kind of Flies of so various a shape; though certainly
+they are some very essential part of the head, and have some very notable
+office assign'd them by Nature, since in all Insects they are to be found
+in one or other form.
+
+Sixthly, at the under part of the face FF, were several of the former sort
+of bended Brisles, and below all, the mouth, out of the middle of which,
+grew the _proboscis_ GHI, which, by means of several joints, whereof it
+seem'd to consist, the Fly was able to move to and fro, and thrust it in
+and out as it pleas'd; the end of this hollow body (which was all over
+cover'd with small short hairs or brisles) was, as 'twere, bent at H, and
+the outer or formost side of the bended part HI, slit, as it were, into two
+chaps, HI, HI, all the outside of which where cover'd with hairs, and
+pretty large brisles; these he could, like two chaps, very readily open and
+shut, and when he seem'd to suck any thing from the surface of a body, he
+would spread abroad those chaps, and apply the hollow part of them very
+close to it.
+
+From either side of the _Proboscis_, within the mouth, grew two other small
+horns, or fingers, KK, which were hairy, but small in this Figure; but of
+another shape, and bigger in proportion, in the 24. _Scheme_, where they
+are marked with GG, which two indeed seem'd a kind of smellers, but whether
+so or not, I cannot positively determine.
+
+The _Thorax_ or middle part of this Fly, was cas'd, both above and beneath,
+with a very firm crust of armour, the upper part more round, and covered
+over with long _conical_ brisles, all whose ends pointed backwards; out of
+the hinder and under part of this grew out in a cluster six leggs, three of
+which are apparent in the Figure, the other three were hid by the body
+plac'd in that posture. The leggs were all much of the same make, being all
+of them cover'd with a strong hairy scale or shel, just like the legs of a
+Crabb or Lobster, and the contrivance of the joints seem'd much the same,
+each legg seem'd made up of eight parts, 1, 2, 3, 4, 5, 6, 7, 8, to the
+eighth or last of which, grew the soles and claws, described before in the
+38. _Observation_.
+
+Out of the upper part of this trunck grew the two wings, which I mention'd
+in the 38. _Observation_, consisting of a film, extended on certain small
+stiff wires or bones: these in a blue Fly, were much longer then the body,
+but in other kind of Flies they are of very differing proportions to the
+body. These films, in many Flies, were so thin, that, like several other
+plated bodies (mention'd in the ninth _Observation_) they afforded all
+varieties of fantastical or transient colours (the reason of which I have
+here endeavoured to explain) they seem'd to receive their nourishment from
+the stalks or wires, which seem'd to be hollow, and neer the upper part of
+the wing LL several of them seem'd jointed, the shape of which will
+sufficiently appear by the black lines in the second Figure of the 26.
+_Scheme_, which is a delineation of one of those wings expanded directly to
+the eyes.
+
+All the hinder part of its body is cover'd with a most curious blue shining
+armour, looking exactly like a polish'd piece of steel brought to that blue
+colour by annealing, all which armour is very thick bestuck with abundance
+of tapering brisles, such as grow on its back, as is visible enough by the
+Figure.
+
+Nor was the inside of this creature less beautifull then its outside, for
+cutting off a part of the belly, and then viewing it, to see if I could
+discover any Vessels, such as are to be found in a greater Animals, and
+even in Snails exceeding manifestly, I found, much beyond my expectation,
+that there were abundance of branchings of Milk-white vessels, no less
+curious then the branchings of veins and arteries in bigger terrestrial
+Animals, in one of which, I found two notable branches, joining their two
+main stocks, as it were, into one common _ductus_; now, to what veins or
+arteries these Vessells were _analogus_, whether to the _vena porta_, or
+the _meseraick vessells_, or the like, or indeed, whether they were veins
+and arteries, or _vasa lactea_, properly so called, I am not hitherto able
+to determine, having not yet made sufficient enquiry; but in all
+particulars, there seems not to be any thing less of curious contrivance in
+these Insects, then in those larger terrestrial Animals, for I had never
+seen any more curious branchings of Vessels, then those I observ'd in two
+or three of these Flies thus opened.
+
+It is a creature active and nimble, so as there are very few creatures like
+it, whether bigger or smaller, in so much, that it will scape and avoid a
+small body, though coming on it exceeding swiftly, and if it sees any thing
+approaching it, which it fears, it presently squats down, as it were, that
+it may be the more ready for its rise.
+
+Nor is it less hardy in the Winter, then active in the Summer, induring all
+the Frosts, and surviving till the next Summer, notwithstanding the bitter
+cold of our Climate; nay, this creature will indure to be frozen, and yet
+not be destroy'd, for I have taken one of them out of the Snow whereon it
+has been frozen almost white, with the Ice about it, and yet by thawing it
+gently by the warmth of a fire, it has quickly reviv'd and flown about.
+
+This kind of Fly seems by the steams or taste of fermenting and putrifying
+meat (which it often kisses, as 'twere, with its _proboscis_ as it trips
+over it) to be stimulated or excited to eject its Eggs or Seed on it,
+perhaps, from the same reason as Dogs, Cats, and many other brute creatures
+are excited to their particular lusts, by the smell of their females, when
+by Nature prepared for generation; the males seeming by those kind of
+smells, or other incitations, to be as much necessitated thereto, as _Aqua
+Regis_ strongly impregnated with a solution of Gold, is forced to
+precipitate it by the affusion of spirit of _Urine_, or a solution of
+_Salt_ of _Tartar_.
+
+One of these put in spirit of _Wine_, was very quickly seemingly kill'd,
+and both its eys and mouth began to look very red, but upon the taking of
+it out, and suffering it to lie three or four hours, and heating it with
+the Sun beams cast through a Burning-glass, it again reviv'd, seeming, as
+it were, to have been all the intermediate time, but dead drunk, and after
+certain hours to grow fresh again and sober.
+
+       *       *       *       *       *
+
+
+Observ. XLIII. _Of the _Water-Insect_ or _Gnat_._
+
+This little creature, described in the first _Figure_ of the 27. _Scheme_,
+was a small scaled or crusted Animal, which I have often observ'd to be
+generated in Rain-water; I have also observ'd it both in Pond and
+River-water. It is suppos'd by some, to deduce its first original from the
+putrifaction of Rain-water, in which, if it have stood any time open to the
+air, you shall seldom miss, all the Summer long, of store of them frisking
+too and fro.
+
+'Tis a creature, wholly differing in shape from any I ever observ'd; nor is
+its motion less strange: It has a very large head, in proportion to its
+body, all covered with a shell, like other _testaceous_ Animals, but it
+differs in this, that it has, up and down several parts of it, several
+tufts of hairs, or brisles, plac'd in the order express'd in the Figure; It
+has two horns, which seem'd almost like the horns of an Oxe, inverted, and,
+as neer as I could guess, were hollow, with tufts of brisles, likewise at
+the top; these horns they could move easily this or that way, and might,
+perchance, be their nostrils. It has a pretty large mouth, which seem'd
+contriv'd much like those of Crabs and Lobsters, by which, I have often
+observ'd them to feed on water, or some imperceptible nutritive substance
+in it.
+
+I could perceive, through the transparent shell, while the Animal surviv'd,
+several motions in the head, thorax, and belly, very distinctly, of
+differing kinds which I may, perhaps, elsewhere endeavour more accurately
+to examine, and to shew of how great benefit the use of a _Microscope_ may
+be for the discovery of Nature's course in the operations perform'd in
+Animal bodies, by which we have the opportunity of observing her through
+these delicate and pellucid teguments of the bodies of Insects acting
+according to her usual course and way, undisturbed, whereas, when we
+endeavour to pry into her secrets by breaking open the doors upon her, and
+dissecting and mangling creatures whil'st there is life yet within them, we
+find her indeed at work, but put into such disorder by the violence
+offer'd, as it may easily be imagin'd, how differing a thing we should
+find, if we could, as we can with a _Microscope_ in these smaller
+creatures, quietly peep in at the windows, without frighting her out of her
+usual byas.
+
+The form of the whole creature, as it appear'd in the _Microscope_, may,
+without troubling you with more descriptions, be plainly enough perceiv'd
+by the _Scheme_, the hinder part or belly consisting of eight several
+jointed parts, namely, ABCDEFGH, of the first _Figure_, from the midst of
+each of which, on either side issued out three or four small brisles or
+hairs, I, I, I, I, I, the tail was divided into two parts of very differing
+make; one of them, namely, K, having many tufts of hair or brisles, which
+seem'd to serve both for the finns and tail, for the Oars and Ruder of this
+little creature, wherewith it was able, by frisking and bending its body
+nimbly to and fro, to move himself any whither, and to skull and steer
+himself as he pleas'd, the other part, L, seem'd to be, as 'twere, the
+ninth division of his belly, and had many single brisles on either side.
+From the end V, of which, through the whole belly, there was a kind of Gut
+of a darker colour, MMM, wherein, by certain _Peristaltick_ motions there
+was a kind of black substance mov'd upwards and downwards through it from
+the orbicular part of it, N, (which seem'd the _Ventricle_, or stomach) to
+the tail V, and so back again, which _peristaltick_ motion I have observ'd
+also in a Louse, a Gnat, and several other kinds of transparent body'd
+Flies. The _Thorax_ or chest of this creature OOOO, was thick and short,
+and pretty transparent, for through it I could see the white heart (which
+is the colour also of the bloud in these, and most other Insects) to beat,
+and several other kind of motions. It was bestuck and adorn'd up and down
+with several tufts of brisles, such as are pointed out by P, P, P, P, the
+head Q was likewise bestuck with several of those tufts, SSS; it was broad
+and short, had two black eyes, TT, which I could not perceive at all
+pearl'd, as they afterwards appear'd, and two small horns, RR, such as I
+formerly describ'd.
+
+Both its motion and rest is very strange, and pleasant, and differing from
+those of most other creatures I have observ'd; for, where it ceases from
+moving its body, the tail of it seeming much lighter then the rest of its
+body, and a little lighter then the water it swims in, presently boys it up
+to the top of the water, where it hangs suspended with the head always
+downward; and like our _Antipodes_, if they do by a frisk get below that
+superficies, they presently ascend again unto it, if they cease moving,
+until they tread, as it were, under that superficies with their tails; the
+hanging of these in this posture, put me in mind of a certain creature I
+have seen in _London_, that was brought out of _America_, which would very
+firmly suspend it self by the tail, with the head downwards, and was said
+to keep in that posture, with her young ones in her false belly, which is a
+Purse, provided by Nature for the production, nutrition, and preservation
+of her young ones, which is described by _Piso_ in the 24. Chapter of the
+fifth Book of his Natural History of _Brasil_.
+
+The motion of it was with the tail forwards, drawing its self backwards, by
+the striking to and fro of that tuft which grew out of one of the stumps of
+its tail. It had another motion, which was more sutable to that of other
+creatures, and that is, with the head forward; for by the moving of his
+chaps (if I may so call the parts of his mouth) it was able to move it self
+downwards very gently towards the bottom, and did, as 'twere, eat up its
+way through the water.
+
+But that which was most observable in this creature, was, its Metamorphosis
+or change; for having kept several of these Animals in a Glass of
+Rain-water, in which they were produc'd, I found, after about a fortnight
+or three weeks keeping, that several of them flew away in Gnats, leaving
+their husks behind them in the water floating under the surface, the place
+where these Animals were wont to reside, whil'st they were inhabitants of
+the water: this made me more diligently to watch them, to see if I could
+find them at the time of their transformation; and not long after, I
+observ'd several of them to be changed into an unusual shape, wholly
+differing from that they were of before, their head and body being grown
+much bigger and deeper, but not broader, and their belly, or hinder part
+smaller, and coyl'd, about this great body much of the fashion represented
+by the prick'd line in the second _Figure_ of the 27. _Scheme_, the head
+and horns now swam uppermost, and the whole bulk of the body seem'd to be
+grown much lighter; for when by my frighting of it, it would by frisking
+out of its tail (in the manner express'd in the Figure by BC) sink it self
+below the surface towards the bottom; the body would more swiftly
+re-ascend, then when it was in its former shape.
+
+I still marked its progress from time to time, and found its body still to
+grow bigger and bigger, Nature, as it were, fitting and accoutring it for
+the lighter Element, of which it was now going to be an inhabitant; for, by
+observing one of these with my _Microscope_, I found the eyes of it to be
+altogether differing from what they seem'd before, appearing now all over
+pearl'd or knobb'd, like the eyes of Gnats, as is visible in the second
+_Figure_ by A. At length, I saw part of this creature to swim above, and
+part beneath the surface of the water, below which though it would quickly
+plunge it self if I by any means frighted it, and presently re-ascend into
+its former posture; after a little longer expectation, I found that the
+head and body of a Gnat, began to appear and stand cleer above the surface,
+and by degrees it drew out its leggs, first the two formost, then the
+other, at length its whole body perfect and entire appear'd out of the husk
+(which it left in the water) standing on its leggs upon the top of the
+water, and by degrees it began to move, and after flew about the Glass a
+perfect Gnat.
+
+I have been the more particular, and large in the relation of the
+transformation of divers of these little Animals which I observ'd, because
+I have not found that any Authour has observ'd the like, and because the
+thing it self is so strange and heterogeneous from the usual progress of
+other Animals, that I judge it may not onely be pleasant, but very usefull
+and necessary towards the compleating of Natural History.
+
+There is indeed in _Piso_, a very odd History, which this relation may make
+the more probable; and that is in the 2. Chapter of the 4. Book of his
+Natural History of _Brasil_, where he says, _Porro praeter tot documenta
+fertilitatis circa vegetabilia & sensitiva marina telluris aemula, accidit
+& illud, quod paucis a Paranambucensi milliaribus, piscatoris uncum citra
+intentionem contingat infigi vadis petrosis, & loco piscis spongia,
+coralla, aliasque arbusculas marinas capi. Inter haec inusitatae formae
+prodit spongiosa arbuscula sesquipedis longitudinis, brevioribus radicibus,
+lapideis nitens vadis, & rupibus infixa, erigiturque in corpus spongiosum
+molle oblongum rotundum turbinatum: intus miris cancellis & alveis
+fabricatum, extus autem tenaci glutine instar Apum propolis undique
+vestitum, ostio satis patulo & profundo in summitate relicto, sicut ex
+altera iconum probe depicta videre licet _(see the third and fourth
+_Figures_ of the 27. _Scheme_.)_ Ita ut Apiarium marinum vere dixeris;
+primo enim intuitu e Mare ad Terram delatum, vermiculis scatebat caeruleis
+parvis, qui mox a calore solis in Muscas, vel Apes potius, easq; exiguas &
+nigras transformebantur, circumvolantesque evanescebant, ita ut de eorum
+mellificatione nihil certi conspici datum fuerit, cum tamen caerosa materia
+propolis Apumque cellae manifeste apparerent, atque ipsa mellis
+qualiscunque substantia proculdubio urinatoribus patebit, ubi curiosius
+inquisiverint haec apiaria, eaque in natali solo & salo diversis temporibus
+penitius lustrarint_.
+
+Which History contains things sufficiently strange to be consider'd, as
+whether the husk were a Plant, growing at the bottom of the Sea before, of
+it self, out of whose putrifaction might be generated these strange kind of
+Magots; or whether the seed of certain Bees, sinking to the bottom, might
+there naturally form it self that vegetable hive, and take root; or,
+whether it might not be placed there by some diving Fly; or, whether it
+might not be some peculiar propriety of that Plant, whereby it might ripen
+or form its vegetable juice into an Animal substance; or, whether it may
+not be of the nature of a Sponge, or rather a Sponge of the nature of this,
+according to some of those relations and conjectures I formerly made of
+that body, is a matter very difficult to be determined. But indeed, in this
+description, the Excellent _Piso_ has not been sufficiently particular in
+the setting down the whole process, as it were to be wish'd: There are
+indeed very odd progresses in the production of several kinds of Insects,
+which are not less instructive then pleasant, several of which, the
+diligent _Goedartius_ has carefully observ'd and recorded, but among all
+his Observations, he has none like this, though that of the _Hemerobius_ be
+somewhat of this kind, which is added as an Appendix by _Johannes Mey_.
+
+I have, for my own particular, besides several of those mention'd by him,
+observ'd divers other circumstances, perhaps, not much taken notice of,
+though very common, which do indeed afford us a very _coercive_ argument to
+admire the goodness and providence of the infinitely wise Creator in his
+most excellent contrivances and dispensations. I have observ'd, at several
+times of the Summer, that many of the leaves of divers Plants have been
+spotted, or, as it were scabbed, and looking on the undersides of those of
+them that have been but a litte irregular, I have perceiv'd them to be
+sprinkled with divers sorts of little Eggs, which letting alone, I have
+found by degrees to grow bigger, and become little Worms with leggs, but
+still to keep their former places, and those places of the leaves, of their
+own accords, to be grown very protuberant upwards, and very hollow, and
+arched underneath, whereby those young creatures are, as it were, shelter'd
+and housed from external injury; divers leaves I have observ'd to grow and
+swell so farr, as at length perfectly to inclose the Animal, which, by
+other observations I have made, I ghess to contain it, and become, as it
+were a womb to it, so long, till it be fit and prepar'd to be translated
+into another state, at what time, like (what they say of) Vipers, they gnaw
+their way through the womb that bred them; divers of these kinds I have met
+with upon Goosberry leaves, Rose-tree leaves, Willow leaves, and many other
+kinds.
+
+There are often to be found upon Rose-trees and Brier bushes, little red
+tufts, which are certain knobs or excrescencies, growing out from the Rind,
+or barks of those kinds of Plants, they are cover'd with strange kinds of
+threads or red hairs, which feel very soft, and look not unpleasantly. In
+most of these, if it has no hole in it, you shall find certain little
+Worms, which I suppose to be the causes of their production; for when that
+Worm has eat its way through, they, having performed what they were
+design'd by Nature to do, by degrees die and wither away.
+
+Now, the manner of their production, I suppose to be thus, that the Alwise
+Creator has as well implanted in every creature a faculty of knowing what
+place is convenient for the hatching, nutrition, and preservation of their
+Eggs and of-springs whereby they are stimulated and directed to convenient
+places, which becom, as 'twere the wombs that perform those offices: As he
+has also suited and adapted a property to those places wherby they grow and
+inclose those seeds, and having inclosed them, provide a convenient
+nourishment for them, but as soon as they have done the office of a womb,
+they die and wither.
+
+The progress of inclosure I have often observ'd in leaves, which in those
+places where those seeds have been cast, have by degrees swell'd and
+inclos'd them, so perfectly round, as not to leave any perceptible passage
+out.
+
+From this same cause, I suppose that Galls, Oak-apples, and several other
+productions of that kind, upon the branches and leaves of Trees, have their
+original, for if you open any of them, when almost ripe, you shall find a
+little Worm in them. Thus, if you open never so many dry Galls, you shall
+find either a hole whereby the Worm has eat its passage out, or if you find
+no passage, you may, by breaking or cutting the Gall, find in the middle of
+it a small cavity, and in it a small body, which does plainly enough yet
+retain a shape, to manifest it once to have been a Worm, though it dy'd by
+a too early reparation from the Oak on which it grew, its navel-string, as
+'twere, being broken off from the leaf or branch by which the Globular body
+that invelop'd it, received its nourishment from the Oak.
+
+And indeed, if we consider the great care of the Creator in the
+dispensations of his providences for the propagation and increase of the
+race, not onely of all kind of Animals, but even of Vegetables, we cannot
+chuse but admire and adore him for his Excellencies, but we shall leave off
+to admire the creature, or to wonder at the strange kind of acting in
+several Animals, which seem to favour so much of reason; it seeming to me
+most manifest, that those are but actings according to their structures,
+and such operations as such bodies, so compos'd, must necessarily, when
+there are such and such circumstances concurring, perform: thus, when we
+find Flies swarming, about any piece of flesh that does begin a little to
+ferment; Butterflies about Colworts, and several other leaves, which will
+serve to hatch and nourish their young; Gnats, and several other Flies
+about the Waters, and marishy places, or any other creatures, seeking and
+placing their Seeds in convenient repositories, we may, if we attentively
+consider and examine it, find that there are circumstances sufficient, upon
+the supposals of the excellent contrivance of their machine, to excite and
+force them to act after such or such a manner; those steams that rise from
+these several places may, perhaps, set several parts of these little
+Animals at work, even as in the contrivance of killing a Fox or Wolf with a
+Gun, the moving of a string, is the death of the Animal; for the Beast, by
+moving the flesh that is laid to entrap him, pulls the string which moves
+the trigger, and that lets go the Cock which on the steel strikes certain
+sparks of fire which kindle the powder in the pann, and that presently
+flies into the barrel, where the powder catching fire rarifies and drives
+out the bullet which kills the Animal; in all which actions, there is
+nothing of intention or ratiocination to be ascrib'd either to the Animal
+or Engine, but all to the ingeniousness of the contriver.
+
+But to return to the more immediate consideration of our Gnat: We have in
+it an Instance, not usual or common, of a very strange _amphibious_
+creature, that being a creature that inhabits the Air, does yet produce a
+creature, that for some time lives in the water as a Fish, though afterward
+(which is as strange) it becomes an inhabitant of the Air, like its Sire,
+in the form of a Fly. And this, methinks, does prompt me to propose certain
+conjectures, as Queries, having not yet had sufficient opportunity and
+leisure to answer them my self from my own Experiments or Observations.
+
+And the first is, Whether all those things that we suppose to be bred from
+corruption and putrifaction, may not be rationally suppos'd to have their
+origination as natural as these Gnats, who, 'tis very probable, were first
+dropt into this Water, in the form of Eggs. Those Seeds or Eggs must
+certainly be very small, which so small a creature as a Gnat yields, and
+therefore, we need not wonder that we find not the Eggs themselves, some of
+the younger of them, which I have observ'd, having not exceeded a tenth
+part of the bulk they have afterwards come to; and next, I have observed
+some of those little ones which must have been generated after the Water
+was inclosed in the Bottle, and therefore most probably from Eggs, whereas
+those creatures have been suppos'd to be bred of the corruption of the
+Water, there being not formerly known any probable way how they should be
+generated.
+
+A second is, whether these Eggs are immediately dropt into the Water by the
+Gnats themselves, or, mediately, are brought down by the falling rain; for
+it seems not very improbable, but that those small seeds of Gnats may
+(being, perhaps, of so light a nature, and having so great a proportion of
+surface to so small a bulk of body) be ejected into the Air, and so,
+perhaps, carried for a good while too and fro in it, till by the drops of
+Rain it be wash'd out of it.
+
+A third is, whether multitudes of those other little creatures that are
+found to inhabit the Water for some time, do not, at certain times, take
+wing and fly into the Air, others dive and hide themselves in the Earth,
+and so contribute to the increase both of the one and the other Element.
+
+       *       *       *       *       *
+
+_Postscript._
+
+A good while since the writing of this Description, I was presented by
+Doctor _Peter Ball_, an ingenious Member of the _Royal Society_, with a
+little Paper of Nuts, which he told me was sent him from a Brother of his
+out of the Countrey, from _Mamhead_ in _Devonshire_, some of them were
+loose, having been, as I suppose, broken off, others were still growing
+fast on upon the sides of a stick, which seem'd by the bark, pliableness of
+it, and by certain strings that grew out of it, to be some piece of the
+root of a Tree; they were all of them dry'd, and a little shrivell'd,
+others more round, of a brown colour; their shape was much like a Figg, but
+very much smaller, some being about the bigness of a Bay-berry, others, and
+the biggest, of a Hazel-Nut. Some of these that had no hole in them, I
+carefully opened with my Knife, and found in them a good large round white
+Maggot, almost as bigg as a small Pea, which seem'd shap'd like other
+Maggots, but shorter. I could not find them to move, though I ghess'd them
+to be alive, because upon pricking them with a Pinn, there would issue out
+a great deal of white _mucous_ matter, which seem'd to be from a voluntary
+contraction of their skin; their husk or matrix consisted of three Coats,
+like the barks of Trees, the outermost being more rough and spongie, and
+the thickest, the middlemost more close, hard, white, and thin, the
+innermost very thin, seeming almost like the skin within an Egg's shell.
+The two outermost had root in the branch or stick, but the innermost had no
+stem or process, but was onely a skin that cover'd the cavity of the Nut.
+All the Nuts that had no holes eaten in them, I found to contain these
+Maggots, but all that had holes, I found empty, the Maggots, it seems,
+having eaten their way through, taken wings and flown away, as this
+following account (which I receiv'd in writing from the same person, as it
+was sent him by his Brother) manifests. _In a moorish black Peaty mould,
+with some small veins of whitish yellow Sands, upon occasion of digging a
+hole two or three foot deep, at the head of a Pond or Pool, to set a Tree
+in, at that depth, were found, about the end of _October 1663._ in those
+very veins of Sand, those Buttons or Nuts, sticking to a little loose
+stick, that is, not belonging to any live Tree, and some of them also free
+by themselves._
+
+_Four or five of which being then open'd, some were found to contain live
+Insects come to perfection, most like to flying _Ants_, if not the same; in
+others, Insects, yet imperfect, having but the head and wings form'd, the
+rest remaining a soft white pulpy substance._
+
+Now, as this furnishes us with one odd History more, very agreeable to what
+I before hinted, so I doubt not, but were men diligent observers, they
+might meet with multitudes of the same kind, both in the Earth and in the
+Water, and in the Air, on Trees, Plants, and other Vegetables, all places
+and things being, as it were, _animarum plena_. And I have often, with
+wonder and pleasure, in the Spring and Summer-time, look'd close to, and
+diligently on, common Garden mould, and in a very small parcel of it, found
+such multitudes and diversities of little _reptiles_, some in husks, others
+onely creepers, many wing'd, and ready for the Air; divers husks or
+habitations left behind empty. Now, if the Earth of our cold Climate be so
+fertile of animate bodies, what may we think of the fat Earth of hotter
+Climates? Certainly, the Sun may there, by its activity, cause as great a
+parcel of Earth to fly on wings in the Air, as it does of Water in steams
+and vapours. And what swarms must we suppose to be sent out of those
+plentifull inundations of water which are poured down by the sluces of Rain
+in such vast quantities? So that we need not much wonder at those
+innumerable clouds of Locusts with which _Africa_, and other hot countries
+are so pestred, since in those places are found all the convenient causes
+of their production, namely, genitors, or Parents, concurrent receptacles
+or matrixes, and a sufficient degree of natural heat and moisture.
+
+I was going to annex a little draught of the Figure of those Nuts sent out
+of _Devonshire_, but chancing to examine Mr. _Parkinson_'s Herbal for
+something else, and particularly about Galls and Oak-apples, I found among
+no less then 24. several kinds of excrescencies of the Oak, which I doubt
+not, but upon examination, will be all found to be the _matrixes_ of so
+many several kinds of Insects; I having observ'd many of them my self to be
+so, among 24. several kinds, I say, I found one described and Figur'd
+directly like that which I had by me, the _Scheme_ is there to be seen, the
+description, because but short, I have here adjoin'd _Theatri Botanici
+trib. 16. Chap. 2. There groweth at the roots of old Oaks in the
+Spring-time, and semetimes also in the very heat of Summer, a peculiar kind
+of Mushrom or Excrescence, call'd _Uva Quercina_, swelling out of the
+Earth, many growing one close unto another, of the fashion of a Grape, and
+therefore took the name, the _Oak-Grape_, and is of a Purplish colour on
+the outside, and white within like Milk, and in the end of Summer becometh
+hard and woody._ Whether this be the very same kind, I cannot affirm, but
+both the Picture and Description come very neer to that I have, but that he
+seems not to take notice of the hollowness or Worm, for which 'tis most
+observable. And therefore 'tis very likely, if men did but take notice,
+they might find very many differing Species of these Nuts, _Ovaries_, or
+_Matrixes_, and all of them to have much the same designation and office.
+And I have very lately found several kinds of Excrescencies on Trees and
+Shrubs, which having endured the Winter, upon opening them, I found most of
+them to contain little Worms, but dead, those things that contain'd them
+being wither'd and dry.
+
+       *       *       *       *       *
+
+
+Observ. XLIV. _Of the tufted or Brush-horn'd _Gnat_._
+
+This little creature was one of those multitudes that fill our _English_
+air all the time that warm weather lasts, and is exactly of the shape of
+that I observ'd to be generated and hatch'd out of those little Insects
+that wriggle up and down in Rain-water. But, though many were of this form,
+yet I observ'd others to be of quite other kinds; nor were all of this or
+the other kind generated out of Water Insects; for whereas I observ'd that
+those that proceeded from those Insects were at their full growth, I have
+also found multitudes of the same shape, but much smaller and tenderer
+seeming to be very young ones, creep up and down upon the leaves of Trees,
+and flying up and down in small clusters, in places very remote from water;
+and this Spring, I observ'd one day, when the Wind was very calm, and the
+afternoon very fair, and pretty warm, though it had for a long time been
+very cold weather, and the wind continued still in the East, several small
+swarms of them playing to and fro in little clouds in the Sun, each of
+which were not a tenth part of the bigness of one of these I here have
+delineated, though very much of the same shape, which makes me ghess, that
+each of these swarms might be the of-spring of one onely Gnat, which had
+been hoorded up in some safe repository all this Winter by some provident
+Parent, and were now, by the warmth of the Spring-air, hatch'd into little
+Flies.
+
+And indeed, so various, and seemingly irregular are the generations or
+productions of Insects, that he that shall carefully and diligently observe
+the several methods of Nature therein, will have infinitely cause further
+to admire the wisdom and providence of the Creator; for not onely the same
+kind of creature may be produc'd from several kinds of ways, but the very
+same creature may produce several kinds: For, as divers Watches may be made
+out of several materials, which may yet have all the same appearance, and
+move after the same manner, that is, shew the hour equally true, the one as
+the other, and out of the same kind of matter, like Watches, may be wrought
+differing ways; and, as one and the same Watch may, by being diversly
+agitated, or mov'd, by this or that agent, or after this or that manner,
+produce a quite contrary effect: So may it be with these most curious
+Engines of Insect's bodies; the All-wise God of Nature, may have so ordered
+and disposed the little _Automatons_, that when nourished, acted, or
+enlivened by this cause, they produce one kind of effect, or animate shape,
+when by another they act quite another way, and another Animal is produc'd.
+So may he so order several materials, as to make them, by several kinds of
+methods, produce similar _Automatons_.
+
+But to come to the Description of this Insect, as it appears through a
+_Microscope_, of which a representation is made in the 28. _Scheme_. Its
+head A, is exceeding small, in proportion to its body, consisting of two
+clusters of pearl'd eyes BB, on each side of its head, whose pearls or
+eye-balls are curiously rang'd like those of other Flies; between these, in
+the forehead of it, there are plac'd upon two small black balls, CC, two
+long jointed horns, tapering towards the top, much resembling the long
+horns of Lobsters, each of whose stems or quills, DD, were brisled or
+brushed with multitudes of small stiff hairs, issuing out every way from
+the several joints, like the strings or sproutings of the herb
+_Horse-tail_, which is oft observ'd to grow among Corn, and for the whole
+shape, it does very much resemble those _brushy Vegetables_; besides these,
+there are two other jointed and brisled horns, or feelers, EE, in the
+forepart of the head, and a _proboscis_, F, underneath, which in some Gnats
+are very long, streight hollow pipes, by which these creatures are able to
+drill and penetrate the skin, and thence, through those pipes suck so much
+bloud as to stuff their bellies so full till they be ready to burst.
+
+This small head, with its appurtenances, is fastned on by a short neck, G,
+to the middle of the _thorax_, which is large, and seems cased with a
+strong black shel, HIK, out of the under part of which, issue six long and
+slender legs, LLLLLL, shap'd just like the legs of Flies, but spun or drawn
+out longer and slenderer, which could not be express'd in the Figure,
+because of their great length; and from the upper part, two oblong, but
+slender transparent wings, MM, shaped somewhat like those of a Fly,
+underneath each of which, as I have observ'd also in divers sorts of Flies,
+and other kinds of Gnats, was placed a small body, N, much resembling a
+drop of some transparent glutinous substance, hardned or cool'd, as it was
+almost ready to fall, for it has a round knob at the end, which by degrees
+grows slenderer into a small stem, and neer the insertion under the wing,
+this stem again grows bigger; these little _Pendulums_, I may so call them,
+the litle creature vibrates to and fro very quick when it moves its wings,
+and I have sometimes observ'd it to move them also, whil'st the wing lay
+still, but always their motion seem'd to further the motion of the wing
+ready to follow; of what use they are, as to the moving of the wing, or
+otherwise, I have not now time to examine.
+
+Its belly was large, as it is usually in all Insects, and extended into
+nine lengths or partitions, each of which was cover'd with round armed
+rings or shells; six of which, OPQRST were transparent, and divers kinds of
+_Peristaltick_ motions might be very easily perceiv'd, whil'st the Animal
+was alive, but especially a small cleer white part V, seemed to beat like
+the heart of a larger Animal. The last three divisios, WXY, were cover'd
+with black and opacous shells. To conclude, take this creature altogether,
+and for beauty and curious contrivances, it may be compared with the
+largest Animal upon the Earth. Nor doth the Alwise Creator seem to have
+shewn less care and providence in the fabrick of it, then in those which
+seem most considerable.
+
+       *       *       *       *       *
+
+
+Observ. XLV. _Of the great Belly'd _Gnat_ or female _Gnat_._
+
+The second Gnat, delineated in the twenty ninth _Scheme_, is of a very
+differing shape from the former; but yet of this sort also, I found several
+of the Gnats, that were generated out of the Water Insect: the wings of
+this, were much larger then those of the other, and the belly much bigger,
+shorter and of an other shape; and, from several particulars, I ghest it to
+be the Female Gnat, and the former to be the Male.
+
+The _thorax_ of this, was much like that of the other, having a very strong
+and ridged back-piece, which went also on either side of its leggs; about
+the wings there were several joynted pieces of Armor, which seem'd
+curiously and conveniently contriv'd, for the promoting and strengthning
+the motion of the wings: its head was much differing from the other, being
+much bigger and neater shap'd, and the horns that grew out between his eyes
+on two little balls, were of a very differing shape from the tufts of the
+other Gnat, these having but a few knots or joynts, and each of those but a
+few, and those short and strong, brisles. The formost horns or feelers,
+were like those of the former Gnat.
+
+One of these Gnats I have suffer'd to pierce the skin of my hand, with its
+_proboscis_, and thence to draw out as much blood as to fill its belly as
+full as it could hold, making it appear very red and transparent; and this
+without any further pain, then whilst it was sinking in its _proboscis_, as
+it is also in the stinging of Fleas: a good argument, that these creatures
+do not wound the skin, and suck the blood out of enmity and revenge, but
+for meer necessity, and to satisfy their hunger. By what means this
+creature is able to suck, we shall shew in another place.
+
+       *       *       *       *       *
+
+
+Observ. XLVI. _Of the white featherwing'd _Moth_ or _Tinea Argentea_._
+
+This white long wing'd Moth, which is delineated in the 30. _Scheme_;
+afforded a lovely object both to the naked Eye, and through a _Microscope_:
+to the Eye it appear'd a small Milk white Fly with four white Wings, the
+two formost somewhat longer then the two hindermost, and the two shorter
+about half an Inch long, each of which four Wings seem'd to consist of two
+small long Feathers, very curiously tufted, or haired on each side, with
+purely white, and exceedingly fine and small Haires, proportion'd to the
+stalks or stems, out of which they grew, much like the tufts of a long
+wing-feather of some Bird, and their stalks or stems were, like those,
+bended backwards and downwards, as may be plainly seen by the draughts of
+them in the Figure.
+
+Observing one of these in my _Microscope_, I found, in the first place,
+that all the Body, Legs, Horns and the Stalks of the Wings, were covered
+over with various kinds of curious white Feathers, which did, with handling
+or touching, easily rubb off and fly about, in so much that looking on my
+Fingers, with which I had handled this Moth, and perceiving on them little
+white specks, I found by my _Microscope_, that they were several of the
+small Feathers of this little creature, that stuck up and down in the
+_rugosities_ of my Skin.
+
+Next, I found that underneath these Feathers, the pretty Insect was covered
+all over with a crusted Shell, like other of those Animals, but with one
+much thinner and tenderer.
+
+Thirdly, I found, as in Birds also is notable, it had differing and
+appropriate kinds of Feathers, that covered several parts of its body.
+
+Fourthly, surveying the parts of its body, with a more accurate and better
+Magnifying _Microscope_, I found that the tufts or haires of its Wings were
+nothing else but a congeries, or thick set cluster of small _vimina_ or
+twiggs, resembling a small twigg of Birch, stript or whitned, with which
+Brushes are usually made, to beat out or brush off the dust from Cloth and
+Hangings. Every one of the twiggs or branches that composed the Brush of
+the Feathers, appeared in this bigger Magnifying Glass (of which EF which
+represents 1/24 part of an Inch, is the scale, as G is of the lesser, which
+is only 1/3) like the figure D. The Feathers also that covered a part of
+his Body, and were interspersed among the brush of his Wings, I found, in
+the bigger Magnifying Glass, of the shape A, consisting of a stalk or stem
+in the middle, and a seeming tuftedness or brushy part on each side. The
+Feathers that cover'd most part of his Body and the stalk of his wings,
+were, in the same _Microscope_, much of the figure B, appearing of the
+shape of a small Feather, and seemed tufted: those which covered the Horns
+and small parts of the Leggs, through the same _Microscope_, appear'd of
+the shape C. Whether the tufts of any or all of these small Feathers,
+consisted of such component particles as the Feathers of Birds, I much
+doubt, because I find that Nature does not alwaies keep, or operate after
+the same method, in smaller and bigger creatures. And of this, we have
+particular Instances in the Wings of several creatures. For whereas, in
+Birds of all kinds, it composes each of the Feathers of which its Wing
+consists, of such an exceeding curious and most admirable and stupendious
+texture, as I else where shew, in the Observations on a Feather; we find it
+to alter its method quite, in the fabrick of the Wings of these minute
+creatures, composing some of thin extended membranes or skins, such as the
+Wings of Dragon-flys; in others, those skins are all over-grown, or pretty
+thick bestuck, with short brisles, as in Flesh-flies; in others, those
+filmes are covered, both on the upper and under side, with small Feathers,
+plac'd almost like the tyles on a House, and are curiously rang'd and
+adorn'd with most lively colours, as is observable in Butter-flies, and
+several kinds of Moths; In others, instead of their films, Nature has
+provided nothing, but a matter of half a score stalks (if I well remember
+the number; for I have not lately met with any of these flys, and did not,
+when I first observ'd them, take sufficient notice of divers particulars)
+and each of these stalks, with a few single branchings on each side,
+resembling much the branched back-bone of a Herring or the like Fish, or a
+thin hair'd Peacocks feather, the top or the eye being broken off. With a
+few of these on either side (which it was able to shut up or expand at
+pleasure, much like a Fann, or rather like the posture of the feathers in a
+wing, whichly all one under another, when shut, and by the side of each
+other, when expanded) this pretty little grey Moth (for such was the
+creature I observ'd, thus wing'd) could very nimbly, and as it seem'd very
+easily move its _corpuscle_, through the Air, from place to place. Other
+Insects have their wings cas'd, or cover'd over, with certain hollow
+shells, shap'd almost like those hollow Trayes, in which Butchers carry
+meat, whose hollow sides being turn'd downwards, do not only secure their
+folded wings from injury of the earth, in which most of those creatures
+reside, but whilst they fly, serves as a help to sustain and bear them up.
+And these are observable in _Scarabees_ and a multitude of other
+terrestrial _crustaceous_ Insects; in which we may yet further observe a
+particular providence of Nature.
+
+Now in all these kinds of wings, we observe this particular, as a thing
+most worthy remark; that where ever a wing consists of discontinued parts,
+the Pores or _interstitia_ between those parts are very seldom, either much
+bigger, or much smaller, then these which we here find between the
+particles of these brushes, so that it should seem to intimate, that the
+parts of the Air are such, that they will not easily or readily, if at all,
+pass through these Pores, so that they seem to be strainers fine enough to
+hinder the particles of the Air (whether hinder'd by their bulk, or by
+their _agitation_, _circulation_, _rotation_ or _undulation_, I shall not
+here determine) from getting through them, and, by that means, serve the
+Animal as well, if not better, then if they were little films. I say, if
+not better, because I have observ'd that all those creatures, that have
+film'd wings, move them aboundantly quicker and more strongly, such as all
+kind of Flies and _Scarabees_ and Batts, then such as have their wings
+covered with feathers, as Butter-flies and Birds, or twiggs, as Moths,
+which have each of them a much slower motion of their wings; That little
+ruggedness perhaps of their wings helping them somewhat, by taking better
+hold of the parts of the Air, or not suffering them so easily to pass by,
+any other way then one.
+
+But what ever be the reason of it, 'tis most evident, that the smooth
+wing'd Insects, have the strongest Muscles or movent parts of their wings,
+and the other much weaker; and this very Insect, we are now describing, had
+a very small _thorax_ or middle part of his body, if compar'd to the length
+and number of his wings; which therefore, as he mov'd them very slowly, so
+must he move them very weakly. And this last propriety do we find somewhat
+observ'd also in bigger kind of Flying creatures, Birds; so that we see
+that the Wisdom and Providence of the All-wise Creator, is not less shewn
+in these small despicable creatures, Flies and Moths, which we have branded
+with a name of ignominy, calling them Vermine, then in those greater and
+more remakable animate bodies, Birds.
+
+I cannot here stand to add any thing about the nature of flying, though,
+perhaps, on another occasion, I may say something on that subject, it being
+such as may deserve a much more accurate examination and scrutiny then it
+has hitherto met with; For to me there seems nothing wanting to make a man
+able to fly, but what may be easily enough supply'd from the Mechanicks
+hitherto known, save onely the want of strength, which the Muscles of a man
+seem utterly uncapable of, by reason of their smalness and texture, but how
+even strength also may be mechanically made, and an artificial Muscle so
+contriv d, that thereby a man shall be able to exert what strength he
+pleases, and to regulate it also to his own mind, I may elsewhere endeavour
+to manifest.
+
+       *       *       *       *       *
+
+
+Observ. XLVII. _Of the _Shepherd Spider_, or long legg'd _Spider_._
+
+The Carter, Shepherd Spider, or long-legg'd Spider, has, for two
+particularities, very few similar creatures that I have met with, the
+first, which is discoverable onely by the _Microscope_, and is in the first
+and second _Figures_ of the 31. _Scheme_, plainly describ'd, is the curious
+contrivance of his eyes, of which (differing from most other Spiders) he
+has onely two, and those plac'd upon the top of a small pillar or hillock,
+rising out of the middle of the top of its back, or rather the crown of its
+head, for they were fix'd on the very top of this pillar (which is about
+the heighth of one of the transverse Diameters of the eye, and look'd on in
+another posture, appear'd much of the shape, BCD.) The two eyes, BB, were
+placed back to back, with the transparent parts, or the pupils, looking
+towards either side, but somewhat more forward then backwards. C was the
+column or neck on which they stood, and D the crown of the head out of
+which that neck sprung.
+
+These eyes, to appearance, seem'd to be of the very same structure with
+that of larger _binocular_ creatures, seeming to have a very smooth and
+very protuberant _Cornea_, and in the midst of it to have a very black
+pupil, incompassed about with a kind of grey _Iris_, as appears by the
+_Figure_; whether it were able to move these eyes to and fro, I have not
+observ'd, but 'tis not very likely he should, the pillar or neck C, seeming
+to be cover'd and stiffen'd with a crusty shell; but Nature, in
+probability, has supply'd that defect, by making the _Cornea_ so very
+protuberant, and setting it so cleer above the shadowing or obstructing of
+its prospect by the body, that 'tis likely each eye may perceive, though
+not see distinctly, almost a _Hemisphere_, whence having so small and round
+a body plac'd upon such long leggs, it is quickly able so to wind, and turn
+it, as to see any thing distinct. This creature, as do all other Spiders I
+have yet examin'd, does very much differ from most other Insects in the
+Figure of its eyes; for I cannot, with my best _Microscope_, discover its
+eyes to be any ways knobb'd or pearl'd like those of other Insects.
+
+The second Peculiarity which is obvious to the eye, is also very
+remarkable, and that is the prodigious length of its leggs, in proportion
+to its small round body, each legg of this I drew, being above sixteen
+times the length of its whole body, and there are some which have them yet
+longer, and others that seem of the same kind, that have them a great deal
+shorter; the eight leggs are each of them jointed, just like those of a
+Crab, but every of the parts are spun out prodigiously longer in
+proportion; each of these leggs are terminated in a small case or shell,
+shap'd almost like that of a Musle-shell, as is evident in the third
+_Figure_ of the same _Scheme_ (that represents the appearance ot the under
+part or belly of the creature) by the shape of the protuberant _conical_
+body, IIII, &c. These are as 'twere plac'd or fasten'd on to the
+protuberant body of the Insect, which is to be suppos'd very high at M,
+making a kind of blunt cone whereof M is to be suppos'd the _Apex_, about
+which greater cone of the body, the smaller cones of the leggs are plac'd,
+each of them almost reaching to the top in so admirable a manner, as does
+not a little manifest the wisdom of Nature in the contrivance; for these
+long Leavers (as I may so call them) of the legs, having not the advantage
+of a long end on the other side of the _hypomochlion_ or centers on which
+the parts of the leggs move, must necessarily require a vast strength to
+move them, and keep the body ballanc'd and suspended, in so much, that if
+we should suppose a man's body suspended by such a contrivance, an hundred
+and fifty times the strength of a man would not keep the body from falling
+on the breast. To supply therefore each of these leggs with its proper
+strength, Nature has allow'd to each a large Chest or Cell, in which is
+included a very large and strong Muscle, and thereby this little Animal is
+not onely able to suspend its body upon less then these eight, but to move
+it very swiftly over the tops of grass and leaves.
+
+Nor are these eight leggs so prodigiously long, but the ninth, and tenth,
+which are the two claws, KK, are as short, and serve in steed of a
+_proboscis_, for those seem'd very little longer then his mouth; each of
+them had three parts, but very short, the joints KK, which represented the
+third, being longer then both the other. This creature, seems (which I have
+several times with pleasure observ'd) to throw its body upon the prey,
+insteed of its hands, not unlike a hunting Spider, which leaps like a Cat
+at a Mouse. The whole Fabrick was a very pretty one, and could I have
+dissected it, I doubt not but I should have found as many singularities
+within it as without, perhaps, for the most part, not unlike the parts of a
+Crab, which this little creature does in many things, very much resemble;
+the curiosity of whose contrivance, I have in another place examin'd. I
+omit the description of the horns, AA, of the mouth, LL, which seem'd like
+that of a Crab; the speckledness of his shell, which proceeded from a kind
+of feathers or hairs, and the hairiness of his leggs, his large _thorax_
+and little belly, and the like, they being manifested by the Figure; and
+shall onely take notice that the three parts of the body, namely, the head,
+breast, and belly, are in this creature strangely confus'd, so that 'tis
+difficult to determine which is which, as they are also in a Crab; and
+indeed, this seems to be nothing else, but an Air-crab, being made more
+light and nimble, proportionable to the _medium_ wherin it resides; and as
+Air seems to have but one thousandth part of the body of Water, so does
+this Spider seem not to be a thousandth part of the bulk of a Crab.
+
+       *       *       *       *       *
+
+
+Observ. XLVIII. _Of the hunting _Spider_, and several other sorts of
+_Spiders_._
+
+The hunting Spider is a small grey Spider, prettily bespeck'd with black
+spots all over its body, which the _Microscope_ discovers to be a kind of
+feathers like those on Butterflies wings, or the body of the white Moth I
+lately describ'd. Its gate is very nimble by fits, sometimes running, and
+sometimes leaping, like a Grashopper almost, then standing still, and
+setting it self on its hinder leggs, it will very nimbly turn its body, and
+look round it self every way: It has six very conspicuous eyes, two looking
+directly forwards, plac'd just before; two other, on either side of those,
+looking forward and side-ways; and two other about the middle of the top of
+its back or head, which look backwards and side-wards; these seem'd to be
+the biggest. The surface of them all was very black, sphaerical, purely
+polish'd, reflecting a very cleer and distinct Image of all the ambient
+objects, such as a window, a man's hand, a white Paper, or the like. Some
+other properties of this Spider, observ'd by the most accomplish'd Mr.
+_Evelyn_, in his travels in _Italy_, are most emphatically set forth in the
+History hereunto annexed, which he was pleas'd upon my desire to send me in
+writing.
+
+    Of all the sorts of Insects, there is none has afforded me more
+    divertisements then the _Venatores_, which are a sort of _Lupi_, that
+    have their Denns in the rugged walls, and crevices of our houses; a
+    small brown and delicately spotted kind of Spiders, whose hinder leggs
+    are longer then the rest.
+
+    Such I did frequently observe at _Rome_, which espying a Fly at three
+    or four yards distance, upon the Balcony (where I stood) would not make
+    directly to her, but craul under the Rail, till being arriv'd to the
+    _Antipodes_, it would steal up, seldom missing its aim; but if it
+    chanced to want any thing of being perfectly opposite, would at first
+    peep, immediatly slide down again, till taking better notice, it would
+    come the next time exactly upon the Fly's back: But, if this hapn'd not
+    to be within a competent leap, then would this Insect move so softly,
+    as the very shadow of the Gnomon seem'd not to be more imperceptible,
+    unless the Fly mov'd; and then would the Spider move also in the same
+    proportion, keeping that just time with her motion, as if the same Soul
+    had animated both those little bodies; and whether it were forwards,
+    backwards, or to either side, without at all turning her body, like a
+    well mannag'd Horse: But, if the capricious Fly took wing, and pitch'd
+    upon another place behind our Huntress, then would the Spider whirle
+    its body so nimbly about, as nothing could be imagin'd more swift; by
+    which means, she always kept the head towards her prey, though to
+    appearance, as immovable, as if it had been a Nail driven into the
+    Wood, till by that indiscernable progress (being arriv'd within the
+    sphere of her reach) she made a fatal leap (swift as Lightning) upon
+    the Fly, catching him in the pole, where she never quitted hold till
+    her belly was full, and then carried the remainder home. I have beheld
+    them instructing their young ones, how to hunt, which they would
+    sometimes discipline for not well observing; but, when any of the old
+    ones did (as sometimes) miss a leap, they would run out of the field,
+    and hide them in their crannies, as asham'd, and haply not be seen
+    abroad for four or five hours after; for so long have I watched the
+    nature of this strange Insect, the contemplation of whose so wonderfull
+    sagacity and address has amaz'd me; nor do I find in any chase
+    whatsoever, more cunning and Stratagem observ'd: I have found some of
+    these Spiders in my Garden, when the weather (towards the Spring) is
+    very hot, but they are nothing so eager of hunting as they are in
+    _Italy_.
+
+There are multitudes of other sorts of Spiders, whose eyes, and most other
+parts and properties, are so exceedingly different both from those I have
+describ'd, and from one another, that it would be almost endless, at least
+too long for my present Essay, to describe them, as some with six eyes,
+plac'd in quite another order; others with eight eyes; others with fewer,
+and some with more. They all seem to be creatures of prey, and to feed on
+other small Insects, but their ways of catching them seem very differing:
+the Shepherd Spider by running on his prey; the Hunting Spider by leaping
+on it, other sorts weave Nets, or Cobwebs, whereby they ensnare them,
+Nature having both fitted them with materials and tools, and taught them
+how to work and weave their Nets, and to lie perdue, and to watch
+diligently to run on any Fly, as soon as ever entangled.
+
+Their thread or web seems to be spun out of some viscous kind of excrement,
+lying in their belly, which, though soft when drawn out, is, presently by
+reason of its smallness, hardned and dried by the ambient Air. Examining
+several of which with my _Microscope_, I found them to appear much like
+white Hors-hair, or some such transparent horny substance, and to be of
+very differing magnitudes; some appearing as bigg as a Pigg's brisle,
+others equal to a Horss-hair; other no bigger then a man's hair; others yet
+smaller and finer. I observ'd further, that the radiating chords of the web
+were much bigger, and smoother then those that were woven round, which
+seem'd smaller, and all over knotted or pearl'd, with small transparent
+Globules, not unlike small Crystal Beads or seed Pearls, thin strung on a
+Clew of Silk; which, whether they were so spun by the Spider, or by the
+adventitious moisture of a fogg (which I have observ'd to cover all these
+filaments with such Crystalline Beads) I will not now dispute.
+
+These threads were some of them so small, that I could very plainly, with
+the _Microscope_, discover the same consecutions of colours as in a
+_Prisme_, and they seem'd to proceed from the same cause with those colours
+which I have already describ'd in thin plated bodies.
+
+Much resembling a Cobweb, or a confus'd lock of these Cylinders, is a
+certain white substance which, after a fogg, may be observ'd to fly up and
+down the Air; catching several of these, and examining them with my
+_Microscope_, I found them to be much of the same form, looking most like
+to a flake of Worsted prepar'd to be spun, though by what means they should
+be generated, or produc'd, is not easily imagined: they were of the same
+weight, or very little heavier then the Air; and 'tis not unlikely, but
+that those great white clouds, that appear all the Summer time, may be of
+the same substance.
+
+       *       *       *       *       *
+
+
+Observ. XLIX. _Of an _Ant_ or _Pismire_._
+
+This was a creature, more troublesom to be drawn, then any of the rest, for
+I could not, for a good while, think of a way to make it suffer its body to
+ly quiet in a natural posture; but whil'st it was alive, if its feet were
+fetter'd in Wax or Glew, it would so twist and wind its body, that I could
+not any wayes get a good view of it; and if I killed it, its body was so
+little, that I did often spoile the shape of it, before I could throughly
+view it: for this is the nature of these minute Bodies, that as soon,
+almost, as ever their life is destroy'd, their parts immediately shrivel,
+and lose their beauty; and so is it also with small Plants, as I instanced
+before, in the description of Moss. And thence also is the reason of the
+variations in the beards of wild Oats, and in those of Musk-grass seed,
+that their bodies, being exceeding small, those small variations which are
+made in the surfaces of all bodies, almost upon every change of Air,
+especially if the body be porous, do here become sensible, where the whole
+body is so small, that it is almost nothing but surface; for as in
+vegetable substances, I see no great reason to think, that the moisture of
+the Aire (that, sticking to a wreath'd beard, does make it untwist) should
+evaporate, or exhale away, any faster then the moisture of other bodies,
+but rather that the avolation from, or access of moisture to, the surfaces
+of bodies being much the same, those bodies become most sensible of it,
+which have the least proportion of body to their surface. So is it also
+with Animal substances; the dead body of an Ant, or such little creature,
+does almost instantly shrivel and dry, and your object shall be quite
+another thing, before you can half delineate it, which proceeds not from
+the extraordinary exhalation, but from the small proportion of body and
+juices, to the usual drying of bodies in the Air, especially if warm. For
+which inconvenience, where I could not otherwise remove it, I thought of
+this expedient.
+
+I took the creature, I had design'd to delineate, and put it into a drop of
+very well rectified spirit of Wine, this I found would presently dispatch,
+as it were, the Animal, and being taken out of it, and lay'd on a paper,
+the spirit of Wine would immediately fly away, and leave the Animal dry, in
+its natural posture, or at least, in a constitution, that it might easily
+with a pin be plac'd, in what posture you desired to draw it, and the limbs
+would so remain, without either moving, or shriveling. And thus I dealt
+with this Ant, which I have here delineated, which was one of many, of a
+very large kind, that inhabited under the Roots of a Tree, from whence they
+would sally out in great parties, and make most grievous havock of the
+Flowers and Fruits, in the ambient Garden, and return back again very
+expertly, by the same wayes and paths they went.
+
+It was more then half the bigness of an Earwig, of a dark brown, or reddish
+colour, with long legs, on the hinder of which it would stand up, and raise
+its head as high as it could above the ground, that it might stare the
+further about it, just after the same manner as I have also observ'd a
+hunting Spider to do: and putting my finger towards them, they have at
+first all run towards it, till almost at it; and then they would stand
+round about it, at a certain distance, and smell, as it were, and consider
+whether they should any of them venture any further, till one more bold
+then the rest venturing to climb it, all the rest, if I would have suffered
+them, would have immediately followed: many such other seemingly rational
+actions I have observ'd in this little Vermine with much pleasure, which
+would be too long to be here related; those that desire more of them may
+satisfie their curiosity in _Ligons_ History of the _Barbadoes_.
+
+Having insnar'd several of these into a small Box, I made choice of the
+tallest grown among them, and separating it from the rest, I gave it a Gill
+of Brandy, or Spirit of Wine, which after a while e'en knock'd him down
+dead drunk, so that he became moveless, though at first putting in he
+struggled for a pretty while very much, till at last, certain bubbles
+issuing out of its mouth, it ceased to move; this (because I had before
+found them quickly to recover again, if they were taken out presently) I
+suffered to lye above an hour in the Spirit; and after I had taken it out,
+and put its body and legs into a natural posture, remained moveless about
+an hour; but then, upon a sudden, as if it had been awaken out of a drunken
+sleep, it suddenly reviv'd and ran away; being caught, and serv'd as
+before, he for a while continued struggling and striving, till at last
+there issued several bubbles out of its mouth, and then, _tanquam animam
+expirasset_, he remained moveless for a good while; but at length again
+recovering, it was again redipt, and suffered to lye some hours in the
+Spirit; notwithstanding which, after it had layen dry some three or four
+hours, it again recovered life and motion: Which kind of Experiments, if
+prosecuted, which they highly deserve, seem to me of no inconsiderable use
+towards the invention of the _Latent Scheme_, (as the Noble _Verulam_ calls
+it) or the hidden, unknown Texture of Bodies.
+
+Of what Figure this Creature appear'd through the _Microscope_, the 32.
+_Scheme_ (though not so carefully graven as it ought) will represent to the
+eye, namely, That it had a large head AA, at the upper end of which were
+two protuberant eyes, pearl'd like those of a Fly, but smaller BB; out of
+the Nose, or foremost part, issued two horns CC, of a shape sufficiently
+differing from those of a blew Fly, though indeed they seem to be both the
+same kind of Organ, and to serve for a kind of smelling; beyond these were
+two indented jaws DD, which he open'd side-wayes, and was able to gape them
+asunder very wide; and the ends of them being armed with teeth, which
+meeting went between each other, it was able to grasp and hold a heavy
+body, three or four times the bulk and weight of its own body: It had only
+six legs, shap'd like those of a Fly, which, as I shewed before, is an
+Argument that it is a winged Insect, and though I could not perceive any
+sign of them in the middle part of its body (which seem'd to consist of
+three joints or pieces EFG, out of which sprung two legs), yet 'tis known
+that there are of them that have long wings, and fly up and down in the
+air.
+
+The third and last part of its body III was bigger and larger then the
+other two, unto which it was joyn'd by a very small middle, and had a kind
+of loose shell, or another distinct part of its body H, which seem'd to be
+interpos'd, and to keep the _thorax_ and belly from touching.
+
+The whole body was cas'd over with a very strong armour, and the belly III
+was covered likewise with multitudes of small white shining brisles; the
+legs, horns, head, and middle parts of its body were bestuck with hairs
+also, but smaller and darker.
+
+       *       *       *       *       *
+
+
+Observ. L. _Of the wandring _Mite_._
+
+In _September_ and _October, 1661._ I observ'd in _Oxford_ several of these
+little pretty Creatures to wander to and fro, and often to travel over the
+plains of my Window. And in _September_ and _October, 1663._ I observ'd
+likewise several of these very same Creatures traversing a window at
+_London_, and looking without the window upon the subjacent wall, I found
+whole flocks of the same kind running to and fro among the small groves and
+thickets of green moss, and upon the curiously spreading vegetable blew or
+yellow moss, which is a kind of a Mushrome or Jews-ear.
+
+These Creatures to the naked eye seemed to be a kind of black Mite, but
+much nimbler and stronger then the ordinary Cheese-Mites; but examining
+them in a _Microscope_, I found them to be a very fine crusted or shell'd
+Insect, much like that represented in the first Figure of the three and
+thirtieth _Scheme_, with a protuberant oval shell A, indented or pitted
+with an abundance of small pits, all covered over with little white
+brisles, whose points all directed backwards.
+
+It had eight legs, each of them provided with a very sharp tallon, or claw
+at the end, which this little Animal, in its going, fastned into the pores
+of the body over which it went. Each of these legs were bestuck in every
+joynt of them with multitudes of small hairs, or (if we respect the
+proportion they bore to the bigness of the leg) turnpikes, all pointing
+towards the claws.
+
+The _Thorax_, or middle parts of the body of this Creature, was exceeding
+small, in respect both of the head and belly, it being nothing but that
+part which was covered by the two shells BB, though it seem'd to grow
+thicker underneath: And indeed, if we consider the great variety Nature
+uses in proportioning the three parts of the body, (the _Head_, _Thorax_,
+and _Belly_) we shall not wonder at the small proportion of this _Thorax_,
+nor at the vaster bulk of the belly, for could we exactly anatomise this
+little Creature, and observe the particular designs of each part, we should
+doubtless, as we do in all her more manageable and tractable fabricks, find
+much more reason to admire the excellency of her contrivance and
+workmanship, then to wonder, it was not made otherwise.
+
+The head of this little Insect was shap'd somewhat like a Mite's, that is,
+it had a long snout, in the manner of a Hogs, with a knobbed ridge running
+along the middle of it, which was bestuck on either side with many small
+brisles, all pointing forward, and two very large pikes or horns, which
+rose from the top of the head, just over each eye, and pointed forward
+also. It had two pretty large black eyes on either side of the head EE,
+from one of which I could see a very bright reflection of the window, which
+made me ghess, that the _Cornea_ of it was smooth, like those of bigger
+Insects. Its motion was pretty quick and strong, it being able very easily
+to tumble a stone or clod four times as big as its whole body.
+
+At the same time and place, and divers times since, I have observed with my
+_Microscope_, another little Insect, which, though I have not annexed the
+picture of, may be worth noting, for its exceeding nimbleness as well as
+smalness; it was as small as a Mite, with a body deep and ridged, almost
+like a Flea; it had eight blood-red legs, not very long, but slender; and
+two horns or feelers before. Its motion was so exceeding quick, that I have
+often lost sight of one I have observed with my naked eye; and though, when
+it was not frighted, I was able to follow the motions of some with my
+_Microscope_; yet if it were never so little startled, it posted away with
+such speed, and turn'd and winded it self so quick, that I should presently
+lose sight of it.
+
+When I first observ'd the former of these Insects, or Mites, I began to
+conjecture, that certainly I had found out the vagabond Parents of those
+Mites we find in Cheeses, Meal, Corn, Seeds, musty Barrels, musty Leather,
+&c. these little Creatures, wandring to and fro every whither, might
+perhaps, as they were invited hither and thither by the musty steams of
+several putrifying bodies, make their invasions upon those new and pleasing
+territories, and there spending the remainder of their life, which might be
+perhaps a day, or thereabouts, in very plentiful and riotous living, might
+leave their off-spring behind them, which by the change of the soil and
+Country they now inhabite, might be quite alter'd from the hew of their
+_primogenitors_, and, like _Mores_ translated into Northern _European_
+Climates, after a little time, change both their skin and shape. And this
+seems yet more probable in these Insects, because that the soil or body
+they inhabit, seems to be almost half their parent, for it not only hatches
+and brings those little eggs, or seminal principles, to perfection, but
+seems to augment and nourish them also before they are hatch'd or shaped;
+for it is obvious enough to be observ'd, that the eggs of many other
+Insects, and particularly of Mites, are increas'd in bulk after they are
+laid out of the bodies of the Insects, and plump'd sometimes into many
+times their former bigness, so that the bodies they are laid in being, as
+it were, half their mothers, we shall not wonder that it should have such
+an active power to change their forms. We find by relations how much the
+_Negro_ Women do besmeer the of-spring of the _Spaniard_, bringing forth
+neither white-skinn'd nor black, but tawny hided _Mulattos_.
+
+Now, though I propound this as probable, I have not yet been so farr
+certify'd by Observations as to conclude any thing, either positively or
+negatively, concerning it. Perhaps, some more lucky diligence may please
+the curious Inquirer with the discovery of this, to be a truth, which I now
+conjecture, and may thereby give him a satisfactory account of the cause of
+those creatures, whose original seems yet to obscure, and may give him
+cause to believe, that many other animate beings, that seem also to be the
+mere product of putrifaction, may be innobled with a Pedigree as ancient as
+the first creation, and farr exceed the greatest beings in their numerous
+Genealogies. But on the other side, if it should be found that these, or
+any other animate body, have no immediate similar Parent, I have in another
+place set down a conjectural _Hypothesis_ whereby those _Phaenomena_ may
+likely enough be solv'd, wherein the infinite wisdom and providence of the
+Creator is no less rare and wonderfull.
+
+       *       *       *       *       *
+
+
+Observ. LI. _Of the _Crab-like_ Insect._
+
+Reading one day in _Septemb._ I chanced to observe a very smal creature
+creep over the Book I was reading, very slowly; having a _Microscope_ by
+me, I observ'd it to be a creature of a very unusual form, and that not
+less notable; such as is describ'd in the second _Figure_ of the 33.
+_Scheme_. It was about the bigness of a large Mite, or somewhat longer, it
+had ten legs, eight of which, AAAA, were topt with very sharp claws, and
+were those upon which he walk'd, seeming shap'd much like those of a Crab,
+which in many other things also this little creature resembled; for the two
+other claws, BB, which were the formost of all the ten, and seem'd to grow
+out of his head, like the horns of other Animals, were exactly form'd in
+the manner of Crabs or Lobsters claws, for they were shap'd and jointed
+much like those represented in the _Scheme_ and the ends of them were
+furnish'd with a pair of claws or pincers, CC, which this little animal did
+open and shut at pleasure: It seem'd to make use of those two horns or
+claws both for feelers and holders; for in its motion it carried these
+aloft extended before, moving them to and fro, just as a man blindfolded
+would do his hands when he is fearfull of running against a wall, and if I
+put a hair to it, it would readily take hold of it with these claws, and
+seem to hold it fast. Now, though these horns seem'd to serve him for two
+uses, namely, for feeling and holding; yet he seem'd neither blind, having
+two small black spots, DD, which by the make of them, and the bright
+reflection from them seem'd to be his eyes, nor did it want other hands,
+having another pair of claws, EE, very neer plac'd to its mouth, and seem'd
+adjoining to it.
+
+The whole body was cased over with armour-shells, as is usuall in all those
+kinds of _crustaceous_ creatures, especially about their bellies, and
+seem'd of three kinds, the head F seem'd cover'd with a kind of scaly
+shell, the _thorax_ with two smooth shells, or Rings, GG, and the belly
+with eight knobb'd ones. I could not certainly find whether it had under
+these last shells any wings, but I suspect the contrary; for I have not
+found any wing'd Insect with eight leggs, two of those leggs being always
+converted into wings, and, for the most part, those that have but six, have
+wings.
+
+This creature, though I could never meet with more then one of them, and so
+could not make so many examinations of it as otherwise I would, I did
+notwithstanding, by reason of the great curiosity that appear'd to me in
+its shape, delineate it, to shew that, in all likelihood, Nature had
+crouded together into this very minute Insect, as many, and as excellent
+contrivances, as into the body of a very large Crab, which exceeds it in
+bulk, perhaps, some Millions of times; for as to all the apparent parts,
+there is a greater rather then a less multiplicity of parts, each legg has
+as many parts, and as many joints as a Crabs, nay, and as many hairs or
+brisles; and the like may be in all the other visible parts; and 'tis very
+likely, that the internal curiosities are not less excellent: It being a
+general rule in Nature's proceedings, that where she begins to display any
+excellency, if the subject be further search'd into, it will manifest, that
+there is not less curiosity in those parts which our single eye cannot
+reach, then in those which are more obvious.
+
+       *       *       *       *       *
+
+
+Observ. LII. _Of the small Silver-colour'd _Book-worm_._
+
+As among greater Animals there are many that are scaled, both for ornament
+and defence, so are there not wanting such also among the lesser bodies of
+Insects, whereof this little creature gives us an Instance. It is a small
+white Silver-shining Worm or Moth, which I found much conversant among
+Books and Papers, and is suppos'd to be that which corrodes and eats holes
+through the leaves and covers; it appears to the naked eye, a small
+glittering Pearl-colour'd Moth, which upon the removing of Books and Papers
+in the Summer, is often observ'd very nimbly to scud, and pack away to some
+lurking cranney, where it may the better protect itself from any appearing
+dangers. Its head appears bigg and blunt, and its body tapers from it
+towads the tail, smaller and smaller, being shap'd almost like a Carret.
+
+This the _Microscopical_ appearance will more plainly manifest, which
+exhibits, in the third _Figure_ of the 33. _Scheme_, a conical body,
+divided into fourteen several partitions, being the appearance of so many
+several shels, or shields that cover the whole body, every of these shells
+are again cover'd or tiled over with a multitude of thin transparent
+scales, which, from the multiplicity of their reflecting surfaces, make the
+whole Animal appear of a perfect Pearl-colour.
+
+Which, by the way, may hint us the reason of that so much admired
+appearance of those so highly esteem'd bodies, as also of the like in
+mother of Pearl-shells, and in multitudes of other shelly Sea-substances;
+for they each of them consisting of an infinite number of very thin shells
+or laminated orbiculations, cause such multitudes of reflections, that the
+compositions of them together with the reflections of others that are so
+thin as to afford colours (of which I elsewhere give the reason) gives a
+very pleasant reflection of light. And that this is the true cause, seems
+likely, first, because all those so appearing bodies are compounded of
+multitudes of plated substances. And next that, by ordering any trasparent
+substance after this manner, the like _Phaenomena_ may be produc'd; this
+will be made very obvious by the blowing of Glass into exceeding thin
+shells, and then breaking them into scales, which any lamp-worker will
+presently do; for a good quantity of these scales, laid in a heap together,
+have much the same resemblance of Pearls. Another way, not less instructive
+and pleasant, is a way which I have several times done, which is by working
+and tossing, as 'twere, a parcel of pure crystalline glass whilst it is
+kept glowing hot in the blown flame of a Lamp, for, by that means, that
+purely transparent body will be so divided into an infinite number of
+plates, or small strings, with interpos'd aerial plates and _fibres_, that
+from the multiplicity of the reflections from each of those internal
+surfaces, it may be drawn out into curious Pearl-like or Silver wire, which
+though small, will yet be opacous; the same thing I have done with a
+composition of red _Colophon_ and _Turpentine_, and a little Bee's Wax, and
+may be done likewise with Birdlime, and such like glutinous and transparent
+bodies: But to return to our description.
+
+The small blunt head of this Insect was furnish'd on either side of it with
+a cluster of eyes, each of which seem'd to contain but a very few, in
+comparison of what I had observ'd the clusters of other Insects to abound
+with; each of these clusters were beset with a row of small brisles, much
+like the _cilia_ or hairs on the eye-lids, and, perhaps, they serv'd for
+the same purpose. It had two long horns before, which were streight, and
+tapering towards the top, curiously ring'd or knobb'd, and brisled much
+like the Marsh Weed, call'd Horse-tail, or Cats-tail, having at each knot a
+fring'd Girdle, as I may so call it, of smaller hairs, and several bigger
+and larger brisles, here and there dispers'd among them: besides these, it
+had two shorter horns, or feelers, which were knotted and fring'd, just as
+the former, but wanted brisles, and were blunt at the ends; the hinder part
+of the creature was terminated with three tails, in every particular
+resembling the two longer horns that grew out of the head: The leggs of it
+were scal'd and hair'd much like the rest, but are not express'd in this
+_Figure_, the Moth being intangled all in Glew, and so the leggs of this
+appear'd not through the Glass which looked perpendicularly upon the back.
+
+This Animal probably feeds upon the Paper and covers of Books, and
+perforates in them several small round holes, finding, perhaps, a
+convenient nourishment in those hulks of Hemp and Flax, which have pass'd
+through so many scourings, washings, dressings and dryings, as the parts of
+old Paper must necessarily have suffer'd; the digestive faculty, it seems,
+of these little creatures being able yet further to work upon those
+stubborn parts, and reduce them into another form.
+
+And indeed, when I consider what a heap of Saw-dust or chips this little
+creature (which is one of the teeth of Time) conveys into its intrals, I
+cannot chuse but remember and admire the excellent contrivance of Nature,
+in placing in Animals such a fire, as is continually nourished and supply'd
+by the materials convey'd into the stomach, and _fomented_ by the bellows
+of the lungs; and in so contriving the most admirable fabrick of Animals,
+as to make the very spending and wasting of that fire, to be instrumental
+to the procuring and collecting more materials to augment and cherish it
+self, which indeed seems to be the principal end of all the contrivances
+observable in bruit Animals.
+
+       *       *       *       *       *
+
+
+Observ. LIII. _Of a _Flea_._
+
+The strength and beauty of this small creature, had it no other relation at
+all to man, would deserve a description.
+
+For its strength, the _Microscope_ is able to make no greater discoveries
+of it then the naked eye, but onely the curious contrivance of its leggs
+and joints, for the exerting that strength, is very plainly manifested,
+such as no other creature, I have yet observ'd, has any thing like it; for
+the joints of it are so adapted, that he can, as 'twere, fold them short
+one within another, and suddenly stretch, or spring them out to their whole
+length, that is, of the fore-leggs, the part A, of the 34. _Scheme_, lies
+within B, and B within C, parallel to, or side by side each other; but the
+parts of the two next, lie quite contrary, that is, D without E, and E
+without F, but parallel also; but the parts of the hinder leggs, G, H and
+I, bend one within another, like the parts of a double jointed Ruler, or
+like the foot, legg and thigh of a man; these six leggs he clitches up
+altogether, and when he leaps, springs them all out, and thereby exerts his
+whole strength at once.
+
+But, as for the beauty of it, the _Microscope_ manifests it to be all over
+adorn'd with a curiously polish'd suit of _sable_ Armour, neatly jointed,
+and beset with multitudes of sharp pinns, shap'd almost like Porcupine's
+Quills, or bright conical Steel-bodkins; the head is on either side
+beautify'd with a quick and round black eye K, behind each of which also
+appears a small cavity, L, in which he seems to move to and fro a certain
+thin film beset with many small transparent hairs, which probably may be
+his ears; in the forepart of his head, between the two fore-leggs, he has
+two small long jointed feelers, or rather smellers, MM, which have four
+joints, and are hairy, like those of several other creatures; between
+these, it has a small _proboscis_, or _probe_, NNO, that seems to consist
+of a tube NN, and a tongue or sucker O, which I have perceiv'd him to slip
+in and out. Besides these, it has also two chaps or biters PP, which are
+somewhat like those of an Ant, but I could not perceive them tooth'd; these
+were shap'd very like the blades of a pair of round top'd Scizers, and were
+opened and shut just after the same manner; with these Instruments does
+this little busie Creature bite and pierce the skin, and suck out the blood
+of an Animal, leaving the skin inflamed with a small round red spot. These
+parts are very difficult to be discovered, because, for the most part, they
+lye covered between the fore-legs. There are many other particulars, which,
+being more obvious, and affording no great matter of information, I shall
+pass by, and refer the Reader to the Figure.
+
+       *       *       *       *       *
+
+
+Observ. LIV. _Of a Louse._
+
+This is a Creature so officious, that 'twill be known to every one at one
+time or other, so busie, and so impudent, that it will be intruding it self
+in every ones company, and so proud and aspiring withall, that it fears not
+to trample on the best, and affects nothing so much as a Crown; feeds and
+lives very high, and that makes it so saucy, as to pull any one by the ears
+that comes in its way, and will never be quiet till it has drawn blood: it
+is troubled at nothing so much as at a man that scratches his head, as
+knowing that man is plotting and contriving some mischief against it, and
+that makes it oftentime sculk into some meaner and lower place, and run
+behind a mans back, though it go very much against the hair; which ill
+conditions of it having made it better known then trusted, would exempt me
+from making any further description of it, did not my faithful _Mercury_,
+my _Microscope_, bring me other information of it. For this has discovered
+to me, by means of a very bright light cast on it, that it is a Creature of
+a very odd shape; it has a head shap'd like that exprest in 35. _Scheme_
+marked with A, which seems almost Conical, but is a little flatted on the
+upper and under sides, at the biggest part of which, on either side behind
+the head (as it were, being the place where other Creatures ears stand) are
+placed its two black shining goggle eyes BB, looking backwards, and fenced
+round with several small _cilia_, or hairs that incompass it, so that it
+seems this Creature has no very good foresight: It does not seem to have
+any eye-lids, and therefore perhaps its eyes were so placed, that it might
+the better cleanse them with its fore-legs; and perhaps this may be the
+reason, why they so much avoid and run from the light behind them, for
+being made to live in the shady and dark recesses of the hair, and thence
+probably their eye having a great aperture, the open and clear light,
+especially that of the Sun, must needs very much offend them; to secure
+these eyes from receiving any injury from the hairs through which it
+passes, it has two horns that grow before it, in the place where one would
+have thought the eyes should be; each of these CC hath four joynts, which
+are fringed, as 'twere, with small brisles, from which to the tip of its
+snout D, the head seems very round and tapering, ending in a very sharp
+nose D, which seems to have a small hole, and to be the passage through
+which he sucks the blood. Now whereas if it be plac'd on its back, with its
+belly upwards, as it is in the 35. _Scheme_, it seems in several Positions
+to have a resemblance of chaps, or jaws, as is represented in the Figure by
+EE, yet in other postures those dark strokes disappear; and having kept
+several of them in a box for two or three dayes, so that for all that time
+they had nothing to feed on, I found, upon letting one creep on my hand,
+that it immediately fell to sucking, and did neither seem to thrust its
+nose very deep into the skin, nor to open any kind of mouth, but I could
+plainly perceive a small current of blood, which came directly from its
+snout, and past into its belly; and about A there seem'd a contrivance,
+somewhat resembling a Pump, pair of Bellows, or Heart, for by a very swift
+_systole_ and _diastole_ the blood seem'd drawn from the nose, and forced
+into the body. It did not seem at all, though I viewed it a good while as
+it was sucking, to thrust more of its nose into the skin then the very
+snout D, nor did it cause the least discernable pain, and yet the blood
+seem'd to run through its head very quick and freely, so that it seems
+there is no part of the skin but the blood is dispers'd into, nay, even
+into the _cuticula_; for had it thrust its whole nose in from D to CC, it
+would not have amounted to the supposed thickness of that _tegument_, the
+length of the nose being not more then a three hundredth part of an inch.
+It has six legs, covered with a very transparent shell, and joynted exactly
+like a Crab's, or Lobster's; each leg is divided into six parts by these
+joynts, and those have here and there several small hairs; and at the end
+of each leg it has two claws, very properly adapted for its peculiar use,
+being thereby inabled to walk very securely both on the skin and hair; and
+indeed this contrivance of the feet is very curious, and could not be made
+more commodiously and compendiously, for performing both these requisite
+motions, of walking and climbing up the hair of a mans head, then it is:
+for, by having the lesser claw (a) set so much short of the bigger (b) when
+it walks on the skin the shorter touches not, and then the feet are the
+same with those of a Mite, and several other small Insects, but by means of
+the small joynts of the longer claw it can bend it round, and so with both
+claws take hold of a hair, in the manner represented in the Figure, the
+long transparent Cylinder FFF, being a Man's hair held by it.
+
+The _Thorax_ seem'd cas'd with another kind of substance then the belly,
+namely, with a thin transparent horny substance, which upon the fasting of
+the Creature did not grow flaccid; through this I could plainly see the
+blood, suck'd from my hand, to be variously distributed, and mov'd to and
+fro; and about G there seem'd a pretty big white substance, which seem'd to
+be moved within its _thorax_; besides, there appear'd very many small
+milk-white vessels, which crost over the breast between the legs, out of
+which, on either side, were many small branchings, these seem'd to be the
+veins and arteries, for that which is analogus to blood in all Insects is
+milk-white.
+
+The belly is covered with a transparent substance likewise, but more
+resembling a skin then a shell, for 'tis grain'd all over the belly just
+like the skin in the palms of a man's hand, and when the belly is empty,
+grows very flaccid and wrinkled; at the upper end of this is placed the
+stomach HH, and perhaps also the white spot II may be the liver or
+_pancreas_, which, by the _peristalick_ motion of the guts, is a little
+mov'd to and fro, not with a _systole_ and _diastole_, but rather with a
+thronging or justling motion. Viewing one of these Creatures, after it had
+fasted two dayes, all the hinder part was lank and flaccid, and the white
+spot II hardly mov'd, most of the white branchings disappear'd, and most
+also of the redness or sucked blood in the guts, the _peristaltick_ motion
+of which was scarce discernable; but upon the suffering it to suck, it
+presently fill'd the skin of the belly, and of the six scolop'd embosments
+on either side, as full as it could be stuft, the stomach and guts were as
+full as they could hold; the _peristaltick_ motion of the gut grew quick,
+and the justling motion of II accordingly; multitudes of milk-white vessels
+seem'd quickly filled, and turgid, which were perhaps the veins and
+arteries and the Creature was so greedy, that though it could not contain
+more, yet it continued sucking as fast as ever, and as fast emptying it
+self behind: the digestion of this Creature must needs be very quick, for
+though I perceiv'd the blood thicker and blacker when suck'd, yet, when in
+the guts, it was of a very lovely ruby colour, and that part of it, which
+was digested into the veins, seemed white; whence it appears, that a
+further digestion of blood may make it milk, at least of a resembling
+colour: What is else observable in the figure of this Creature, may be seen
+by the 35. _Scheme_.
+
+       *       *       *       *       *
+
+
+Observ. LV. _Of _Mites_._
+
+The least of _Reptiles_ I have hitherto met with, is a Mite, a Creature
+whereof there are some so very small, that the sharpest sight, unassisted
+with Glasses, is not able to discern them, though, being white of
+themselves, they move on a black and smooth surface; and the Eggs, out of
+which these Creatures seem to be hatch'd, are yet smaller, those being
+usually not above a four or five hundredth part of a well grown Mite, and
+those well grown Mites not much above one hundredth of an inch in
+thickness; so that according to this reckoning there may be no less then a
+million of well grown Mites contain'd in a cubick inch, and five hundred
+times as many Eggs.
+
+Notwithstanding which minuteness a good _Microscope_ discovers those small
+movable specks to be very prettily shap'd Insects, each of them furnished
+with eight well shap'd and proportion'd legs, which are each of them
+joynted or bendable in eight several places, or joynts, each of which is
+covered, for the most part, with a very transparent shell, and the lower
+end of the shell of each joynt is fringed with several small hairs; the
+contrivance of the joynts seems the very same with that of Crabs and
+Lobsters legs, and like those also, they are each of them terminated with a
+very sharp claw or point; four of these legs are so placed, that they seem
+to draw forwards, the other four are placed in a quite contrary position,
+thereby to keep the body backwards when there is occasion.
+
+[15]The body, as in other larger Insects, consists of three regions or
+parts; the hinder or belly A, seems covered with one intire shell, the
+middle, or chest, seems divided into two shells BC. which running one
+within the other, the Mite is able to shrink in and thrust out as it finds
+occasion, as it can also the snout D. The whole body is pretty transparent,
+so that being look'd on against the light, divers motions within its body
+may be perceived; as also all the parts are much more plainly delineable,
+then in other postures, to the light. The shell, especially that which
+covers the back, is curiously polisht, so that 'tis easie to see, as in a
+_convex_ Looking-glass, or _foliated_ Glass-ball, the picture of all the
+objects round about; up and down, in several parts of its body, it has
+several small long white hairs growing out of its shell, which are often
+longer then the whole body, and are represented too short in the first and
+second Figures; they seem all pretty straight and plyable, save only two
+upon the fore-part of its body, which seem to be the horns, as may be seen
+in the Figures; the first whereof is a prospect of a smaller sort of Mites
+(which are usually more plump) as it was _passant_ to and fro; the second
+is the prospect of one fixt on its tail (by means of a little mouth-glew
+rub'd on the object plate) exhibiting the manner of the growing of the
+legs, together with their several joynts.
+
+This Creature is very much diversify'd in shape, colour, and divers other
+properties, according to the nature of the substance out of which it seems
+to be ingendred and nourished, being in one substance more long, in another
+more round, in some more hairy, in others more smooth, in this nimble, in
+that slow, here pale and whiter, there browner, blacker, more transparent,
+&c. I have observed it to be resident almost on all kinds of substances
+that are mouldy, or putrifying, and have seen it very nimbly meshing
+through the thickets of mould, and sometimes to lye _dormant_ underneath
+them; and 'tis not unlikely, but that it may feed on that vegetating
+substance, _spontaneous Vegetables_ seeming a food proper enough for
+_spontaneous Animals_,
+
+But whether indeed this Creature, or any other, be such or not, I cannot
+positively, from any Experiment, or Observation, I have yet made,
+determine. But, as I formerly hinted, it seems probable, that some kind of
+wandring Mite may sow, as 'twere, the first seeds, or lay the first eggs,
+in those places, which Nature has instructed them to know convenient for
+the hatching and nourishing their young; and though perhaps the prime
+Parent might be of a shape very differing from what the offspring, after a
+little while, by reason of the substance they feed on, or the Region (as
+'twere) they inhabite; yet perhaps even one of these alter'd progeny,
+wandering again from its native soil, and lighting on by chance the same
+place from whence its prime Parent came, and there settling, and planting,
+may produce a generation of Mites of the same shapes and properties with
+the first wandring Mite: And from some such accidents as these, I am very
+apt to think, the most sorts of Animals, generally accounted _spontaneous_,
+have their _origination_, and all those various sorts of Mites, that are to
+be met with up and down in divers putrifying substances, may perhaps be all
+of the same kind, and have sprung from one and the same sort of Mites at
+the first.
+
+       *       *       *       *       *
+
+
+Observ. LVI. _Of a small Creature hatch'd on a Vine._
+
+There is, almost all the Spring and Summer time, a certain small, round,
+white Cobweb, as 'twere, about the bigness of a Pea, which sticks very
+close and fast to the stocks of Vines nayl'd against a warm wall: being
+attentively viewed, they seem cover'd, upon the upper side of them, with a
+small husk, not unlike the scale, or shell of a Wood-louse, or Hog-louse, a
+small Insect usually found about rotten wood, which upon touching presently
+rouls it self into the form of a peppercorn: Separating several of these
+from the stock, I found them, with my _Microscope_, to consist of a shell,
+which now seemed more likely to be the husk of one of these Insects: And
+the fur seem'd a kind of cobweb, consisting of abundance of small
+filaments, or sleaves of cobwebs. In the midst of this, if they were not
+hatch'd, and run away before, the time of which hatching was usually about
+the latter end of _June_, or beginning of _July_, I have often found
+abundance of small brown Eggs, such as A and B in the second Figure of the
+36. _Scheme_, much about the bigness of Mites Eggs; and at other times,
+multitudes of small Insects, shaped exactly like that in the third Figure
+marked with X. Its head large, almost half the bigness of its body, which
+is usual in the _foetus_ of most Creatures. It had two small black eyes
+_aa_, and two small long joynted and brisled horns _bb_. The hinder part of
+its body seem'd to consist of nine scales, and the last ended in a forked
+tayl, much like that of a _Cutio_, or Wood louse, out of which grew two
+long hairs; they ran to and fro very swiftly, and were much of the bigness
+of a common Mite, but some of them less: The longest of them seem'd not the
+hundredth part of an inch, and the Eggs usually not above half as much.
+They seemed to have six legs, which were not visible in this I have here
+delineated, by reason they were drawn under its body.
+
+If these Minute creatures were _Wood-lice_ (as indeed from their own shape
+and from the frame, the skin, or shell, that grows on them, one may with
+great probability ghess) it affords us an Instance, whereof perhaps there
+are not many like in Nature, and that is, of the prodigious increase of
+these Creatures, after they are hatch'd and run about; for a common
+Wood-louse, of about half an inch long, is no less then a hundred and
+twenty five thousand times bigger then one of these, which though indeed it
+seems very strange, yet I have observed the young ones of some Spiders have
+almost kept the same proportion to their Dam.
+
+This, methinks, if it be so, does in the next place hint a Quaery, which
+may perhaps deserve a little further examination: And that is, Whether
+there be not many of those minute Creatures, such as Mites, and the like,
+which, though they are commonly thought of otherwise, are only the _pully_,
+or young ones, of much bigger Insects, and not the generating, or parent
+_Insect_, that has layd those Eggs; for having many times observ'd those
+Eggs, which usually are found in great abundance where Mites are found, it
+seems something strange, that so small an Animal should have an Egg so big
+in proportion to its body. Though on the other side, I must confess, that
+having kept divers of those Mites inclosed in a box for a good while, I did
+not find them very much augmented beyond their usual bigness.
+
+What the husk and cobweb of this little white substance should be, I cannot
+imagine, unless it be, that the old one, when impregnated with Eggs, should
+there stay, and fix it self on the Vine, and dye, and all the body by
+degrees should rot, save only the husk, and the Eggs in the body: And the
+heat, or fire, as it were, of the approaching Sun-beams should vivifie
+those Relicts of the corrupted Parent, and out of the ashes, as 'twere, (as
+it is fabled of the _Phoenix_) should raise a new _offspring_ for the
+perpetuation of the _Species_. Nor will the cobweb, as it were, in which
+these Eggs are inclos'd, make much against this Conjecture; for we may, by
+those cobwebs that are carried up and down the Air after a Fog (which with
+my _Microscope_ I have discovered to be made up of an infinite company of
+small filaments or threads) learn, that such a texture of body may be
+otherwise made then by the spinning of a Worm.
+
+       *       *       *       *       *
+
+
+Observ. LVII. _Of the _Eels_ in Vinegar._
+
+Of these small Eels, which are to be found in divers sorts of Vinegar, I
+have little to add besides their Picture, which you may find drawn in the
+third Figure of the 25. _Scheme_: That is, they were shaped much like an
+Eel, save only that their nose A, (which was a little more opacous then the
+rest of their body) was a little sharper, and longer, in proportion to
+their body, and the wrigling motion of their body seem'd to be onely
+upwards and downwards, whereas that of Eels is onely side wayes: They
+seem'd to have a more opacous part about B, which might, perhaps, be their
+Gills; it seeming always the same proportionate distant from their nose,
+from which, to the tip of their tail, C, their body seem'd to taper.
+
+Taking several of these out of their Pond of Vinegar, by the net of a small
+piece of filtring Paper, and laying them on a black smooth Glass plate, I
+found that they could wriggle and winde their body, as much almost as a
+Snake, which made me doubt, whether they were a kind of Eal or Leech.
+
+I shall add no other observations made on this minute Animal, being
+prevented herein by many excellent ones already publish'd by the ingenious,
+Doctor _Power_, among his _Microscopical_ Observations, save onely that a
+quantity of Vinegar repleat with them being included in a small Viol, and
+stop'd very close from the ambient air, all the included Worms in a very
+short time died, as if they had been stifled.
+
+And that their motion seems (contrary to what we may observe in the motion
+of all other Infects) exceeding slow. But the reason of it seems plain, for
+being to move to and fro after that manner which they do, by waving onely,
+or wrigling their body; the tenacity, or glutinousness, and the density or
+resistance of the fluid _medium_ becomes so exceeding sensible to their
+extremely minute bodies, that it is to me indeed a greater wonder that they
+move them so fast as they do, then that they move them no faster. For what
+a vastly greater proportion have they of their superficies to their bulk,
+then Eels or other larger Fishes, and next, the tenacity and density of the
+liquor being much the same to be moved, both by the one and the other, the
+resistance or impediment thence arising to the motions made through it,
+must be almost infinitely greater to the small one then to the great. This
+we find experimentally verify'd in the Air, which though a _medium_ a
+thousand times more rarify'd then the water, the resistance of it to
+motions made through it, is yet so sensible to very minute bodies, that a
+Down-feather (the least of whose parts seem yet bigger then these Eels, and
+many of them almost incomparably bigger, such as the quill and stalk) is
+suspended by it, and carried to and fro as if it had no weight.
+
+       *       *       *       *       *
+
+
+Observ. LVIII. _Of a new Property in the _Air_, and several other
+transparent _Mediums_ nam'd _Inflection_, whereby very many considerable
+_Phaenomena_ are attempted to be solv'd, and divers other uses are hinted._
+
+Since the Invention (and perfecting in some measure) of _Telescopes_, it
+has been observ'd by several, that the Sun and Moon neer the Horizon, are
+disfigur'd (losing that exactly-smooth terminating circular limb, which
+they are observ'd to have when situated neerer the Zenith) and are bounded
+with an edge every way (especially upon the right and left sides) ragged
+and indented like a Saw: which inequality of their limbs, I have further
+observ'd, not to remain always the same, but to be continually chang'd by a
+kind of fluctuating motion, not unlike that of the waves of the Sea, so as
+that part of the limb, which was but even now nick'd or indented in, is now
+protuberant, and will presently be sinking again; neither is this all but
+the whole body of the Luminaries, do in the _Telescope_, seem to be
+depress'd and slatted, the upper, and more especially the under side
+appearing neerer to the middle then really they are, and the right and left
+appearing more remote: whence the whole _Area_ seems to be terminated by a
+kind of Oval. It is further observ'd, that the body, for the most part,
+appears red, or of some colour approaching neer unto it, as some kind of
+yellow; and this I have always mark'd, that the more the limb is slatted or
+ovalled, the more red does the body appear, though not always the contrary.
+It is further observable, that both fix'd Stars and Planets, the neerer
+they appear to the Horizon, the more red and dull they look, and the more
+they are observ'd to twinkle; in so much, that I have seen the Dog-starr to
+vibrate so strong and bright a radiation of light, as almost to dazle my
+eyes, and presently, almost to disappear. It is also observable, that those
+bright scintillations neer the Horizon, are not by much so quick and sudden
+in their consecutions of one another, as the nimbler twinklings of Stars
+neerer the Zenith. This is also notable, that the Starrs neer the Horizon,
+are twinkled with several colours; so as sometimes to appear red, sometimes
+more yellow, and sometimes blue, and this when the Starr is a pretty way
+elevated above the Horizon. I have further, very often seen some of the
+small Starrs of the fifth or sixth magnitude, at certain times to disappear
+for a small moment of time, and again appear more conspicuous, and with a
+greater luster. I have several times, with my naked eye, seen many smaller
+Starrs, such as may be call'd of the seventh or eighth magnitude to appear
+for a short space, and then vanish, which, by directing a small _Telescope_
+towards that part they appear'd and disappear'd in; I could presently find
+to be indeed small Starrs so situate, as I had seen them with my naked eye,
+and to appear twinkling like the ordinary visible Stars; nay, in examining
+some very notable parts of the Heaven, with a three foot Tube, me thought I
+now and then, in several parts of the constellation, could perceive little
+twinklings of Starrs, making a very short kind of apparition, and presently
+vanishing, but noting diligently the places where they thus seem'd to play
+at boe-peep, I made use of a very good twelve foot Tube, and with that it
+was not uneasie to see those, and several other degrees of smaller Starrs,
+and some smaller yet, that seem'd again to appear and disappear, and these
+also by giving the same Object-glass a much bigger aperture, I could
+plainly and constantly see appear in their former places; so that I have
+observ'd some twelve several magnitudes of Starrs less then those of the
+six magnitudes commonly recounted in the Globes.
+
+It has been observ'd and confirm'd by the accuratest Observations of the
+best of our modern Astronomers, that all the Luminous bodies appear above
+the Horizon, when they really are below it. So that the Sun and Moon have
+both been seen above the Horizon, whil'st the Moon has been in an Eclipse.
+I shall not here instance in the great refractions, that the tops of high
+mountains, seen at a distance, have been found to have; all which seem to
+argue the Horizontal refraction, much greater then it is hitherto generally
+believ'd.
+
+I have further taken notice, that not onely the Sun, Moon and Starrs, and
+high tops of mountains have suffer'd these kinds of refraction, but Trees,
+and several bright Objects on the ground: I have often taken notice of the
+twinkling of the reflections of the Sun from a Glass-window at a good
+distance, and of a Candle in the night, but that is not so conspicuous, and
+in observing the setting Sun, I have often taken notice of the tremulation
+of the Trees and Bushes, as well as of the edges of the Sun. Divers of
+these _Phaenomena_ have been taken notice of by several, who have given
+several reasons of them, but I have not yet met with any altogether
+satisfactory, though some of their conjectures have been partly true, but
+partly also false. Setting my self therfore upon the inquiry of these
+_Phaenomena_, I first endeavour'd to be very diligent in taking notice of
+the several particulars and circumstances observable in them; and next, in
+making divers particular Experiments, that might cleer some doubts, and
+serve to determine, confirm, and illustrate the true and adaequate cause of
+each; and upon the whole, I find much reason to think, that the true cause
+of all these _Phaenomena_ is from the _inflection_, or _multiplicate
+refraction_ of those Rays of light within the body of the _Atmosphere_, and
+that it does not proceed from a _refraction_ caus'd by any terminating
+_superficies_ of the Air above, nor from any such exactly defin'd
+_superficies_ within the body of the _Atmosphere_.
+
+This Conclusion is grounded upon these two Propositions:
+
+First, that a _medium_, whose parts are unequally _dense_, and mov'd by
+various motions and transpositions as to one another, will produce all
+these visible effects upon the Rays of light, without any other
+_coefficient_ cause.
+
+Secondly, that there is in the Air or _Atmosphere_ such a variety in the
+constituent parts of it, both as to their _density_ and _rarity_, and as to
+their divers mutations and positions one to another.
+
+By _Density_ and _Rarity_, I understand a property of a transparent body,
+that does either more or less refract a Ray of light (coming obliquely upon
+its superficies out of a third _medium_) toward its perpendicular: As I
+call Glass a more dense body then Water, and Water a more rare body then
+Glass, because of the refractions (more or less deflecting towards the
+perpendicular) that are made in them, of a Ray of light out of the Air that
+has the same inclination upon either of their superficies.
+
+So as to the business of Refraction, spirit of Wine is a more _dense_ body
+then Water, it having been found by an accurate Instrument that measures
+the angles of Refractions to Minutes that for the same refracted angle of
+30 deg..00'. in both those _Mediums_, the angle of incidence in Water was
+but 41 deg..35'. but the angle of the incidence in the trial with spirit of
+Wine was 42 deg.45'. But as to gravity, Water is a more _dense_ body then
+spirit of Wine, for the proportion of the same Water, to the same very well
+rectify'd spirit of Wine was, as 21. to 19.
+
+So as to Refraction, Water is more Dense then Ice; for I have found by a
+most certain Experiment, which I exhibited before divers illustrious
+Persons of the _Royal Society_, that the Refraction of Water was greater
+then that of Ice, though some considerable Authors have affirm'd the
+contrary, and though the Ice be a very hard, and the Water a very fluid
+body.
+
+That the former of the two preceding Propositions is true, may be
+manifested by several Experiments; As first, if you take any two liquors
+differing from one another in density, but yet such as will readily mix: as
+Salt Water, or Brine, & Fresh; almost any kind of Salt dissolv'd in Water,
+and filtrated, so that it be cleer, spirit of Wine and Water; nay, spirit
+of Wine, and spirit of Wine, one more highly rectify'd then the other, and
+very many other liquors; if (I say) you take any two of these liquors, and
+mixing them in a Glass Viol, against one side of which you have fix'd or
+glued a small round piece of Paper, and shaking them well together (so that
+the parts of them may be somewhat disturb'd and move up and down) you
+endeavour to see that round piece of Paper through the body of the liquors,
+you shall plainly perceive the Figure to wave, and to be indented much
+after the same manner as the limb of the Sun through a _Telescope_ seems to
+be, save onely that the mutations here, are much quicker. And if, in steed
+of this bigger Circle, you take a very small spot, and fasten and view it
+as the former, you will find it to appear much like the twinkling of the
+Starrs, though much quicker: which two _Phaenomena_, (for I shall take
+notice of no more at present, though I could instance in multitudes of
+others) must necessarily be caus'd by an _inflection_ of the Rays within
+the terminating superficies of the compounded _medium_, since the surfaces
+of the transparent body through which the Rays pass to the eye, are not at
+all altered or chang'd.
+
+This _inflection_ (if I may so call it) I imagine to be nothing else, but a
+_multiplicate refraction_, caused by the unequal _density_ of the
+constituent parts of the _medium_, whereby the motion, action or progress
+of the Ray of light is hindred from proceeding in a streight line, and
+_inflected_ or _deflected_ by a _curve_. Now, that it is a _curve_ line is
+manifest by this Experiment: I took a Box, such as ADGE, in the first
+_Figure_ of the 37. _Scheme_, whose sides ABCD, and EFGH, were made of two
+smooth flat plates of Glass, then filling it half full with a very strong
+solution of Salt, I filled the other half with very fair fresh water, then
+exposing the opacous side, DHGC, to the Sun, I observ'd both the
+_refraction_ and _inflection_ of the Sun beams, ID & KH, and marking as
+exactly as I could, the points, P, N, O, M, by which the Ray, KH, passed
+through the compounded _medium_, I found them to be in a _curve_ line; for
+the parts of the _medium_ being continually more dense the neerer they were
+to the bottom, the Ray _pf_ was continually more and more deflected
+downwards from the streight line.
+
+This Inflection may be mechanically explained, either by Monsieur _Des
+Cartes_ principles by conceiving the Globuls of the third Element to find
+less and less resistance against that side of them which is downwards, or
+by a way, which I have further explicated in the Inquisition about Colours,
+to be from an obliquation of the pulse of light, whence the under part is
+continually promoted, and consequently refracted towards the perpendicular,
+which cuts the Orbs at right angles. What the particular Figure of the
+_Curve line_, describ'd by this way of light, is, I shall not now stand to
+examine, especially since there may be so many sorts of it as there may be
+varieties of the Positions of the _intermediat_ degrees of _density_ and
+_rarity_ between the bottom and the top of the inflecting Medium.
+
+I could produce many more Examples and Experiments, to illustrate and prove
+this first Proposition, _viz._ that there is such a constitution of some
+bodies as will cause inflection. As not to mention those I have observ'd in
+_Horn_, _Tortoise-Shell_, _transparent Gums_, and _resinous Substances_:
+The _veins_ of Glass, nay, of melted _Crystal_, found, and much complained
+of by Glass-grinders, and others, might sufficiently demonstrate the truth
+of it to any diligent Observator.
+
+But that, I presume, I have by this Example given proof sufficient (_viz.
+ocular demonstration_) to evince, that there is such a modulation, or
+bending of the rayes of light, as I have call'd _inflection_, differing
+both from _reflection_, and _refraction_ (since they are both made in the
+superficies, this only in the middle); and likewise, that this is able or
+sufficient to produce the effects I have ascribed to it.
+
+It remains therefore to shew, that there is such a property in the Air, and
+that it is sufficient to produce all the above mentioned _Phaenomena_, and
+therefore may be the principal, if not the only cause of them.
+
+First, That there is such a property, may be proved from this, that the
+parts of the Air are some of them more condens'd, others more rarified,
+either by the differing heat, or differing pressure it sustains, or by the
+somewhat heterogeneous vapours interspers'd through it. For as the Air is
+more or less rarified, so does it more or less refract a ray of light (that
+comes out of a denser medium) from the perpendicular. This you may find
+true, if you make tryal of this Experiment.
+
+Take a small Glass-bubble, made in the form of that in the second Figure of
+the 37. _Scheme_, and by heating the Glass very hot, and thereby very much
+rarifying the included Air, or, which is better, by rarifying a small
+quantity of water, included in it, into vapours, which will expel the most
+part, if not all the Air, and then sealing up the small neck of it, and
+letting it cool, you may find, if you place it in a convenient Instrument,
+that there will be a manifest difference, as to the refraction.
+
+As if in this second Figure you suppose A to represent a small sight or
+hole, through which the eye looks upon an object, as C, through the
+Glass-bubble B, and the second sight L; all which remain exactly fixt in
+their several places, the object C being so cized and placed, that it may
+just seem to touch the upper and under edge of the hole L: and so all of it
+be seen through the small Glass-ball of rarified Air; then by breaking off
+the small seal'd neck of the Bubble (without at all stirring the sights,
+object, or glass) and admitting the external Air, you will find your self
+unable to see the utmost ends of the object; but the terminating rayes AE
+and AD (which were before refracted to G and F by the rarified Air) will
+proceed almost directly to I and H; which alteration of the rayes (seeing
+there is no other alteration made in the Organ by which the Experiment is
+tryed, save only the admission, or exclusion of the condens'd Air) must
+necessarily be caused by the variation of the _medium_ contain'd in the
+Glass B; the greatest difficulty in the making of which Experiment, is from
+the uneven surfaces of the bubble, which will represent an uneven image of
+the object.
+
+Now, that there is such a difference of the upper and under parts of the
+Air is clear enough evinc'd from the late improvement of the _Torricellian_
+Experiment, which has been tryed at the tops and feet of Mountains; and may
+be further illustrated, and inquired into, by a means, which some whiles
+since I thought of, and us'd, for the finding by what degrees the Air
+passes from such a degree of Density to such a degree of Rarity. And
+another, for the finding what pressure was requisite to make it pass from
+such a degree of Rarefaction to a determinate Density: Which Experiments,
+because they may be useful to illustrate the present Inquiry, I shall
+briefly describe.
+
+[16] I took then a small Glass-pipe AB, about the bigness of a Swans quill,
+and about four foot long, which was very equally drawn, so that, as far as
+I could perceive, no one part was bigger then another: This Tube (being
+open at both ends) I fitted into another small Tube DE, that had a small
+bore just big enough to contain the small Pipe, and this was seal'd up at
+one, and open at the other, end; about which open end I fastned a small
+wooden box C with cement, so that filling the bigger Tube, and part of the
+box, with Quicksilver, I could thrust the smaller Tube into it, till it
+were all covered with the Quicksilver: Having thus done, I fastned my
+bigger Tube against the side of a wall, that it might stand the steadier,
+and plunging the small Tube cleer under the _Mercury_ in the box, I stopt
+the upper end of it very fast with cement, then lifting up the small Tube,
+I drew it up by a small pully, and a string that I had fastned to the top
+of the Room, and found the height of the _Mercurial Cylinder_ to be about
+twenty nine inches.
+
+Then letting down the Tube again, I opened the top, and then thrust down
+the small Tube, till I perceived the Quicksilver to rise within it to a
+mark that I had plac'd just an inch from the top; and immediately clapping
+on a small piece of cement that I had kept warm, I with a hot Iron seal'd
+up the top very fast, then letting it cool (that both the cement might grow
+hard, and more especially, that the Air might come to its temper, natural
+for the Day I try'd the Experiment in) I observ'd diligently, and found the
+included Air to be exactly an Inch.
+
+Here you are to take notice, that after the Air is seal'd up, the top of
+the Tube is not to be elevated above the superficies of the Quicksilver in
+the box, till the surface of that within the Tube be equal to it, for the
+Quicksilver (as I have elsewhere prov'd) being more heterogeneous to the
+Glass then the Air, will not naturally rise up so high within the small
+Pipe, as the superficies of the _Mercury_ in the box, and therefore you are
+to observe, how much below the outward superficies of the _Mercury_ in the
+box, that of the same in the Tube does stand, when the top being open, free
+ingress is admitted to the outward Air.
+
+Having thus done, I permitted the _Cylinder_, or small Pipe, to rise out of
+the box, till I found the surface of the Quicksilver in the Pipe to be two
+inches above that in the box, and found the Air to have expanded it self
+but one sixteenth part of an inch; then drawing up the small pipe, till I
+found the height of the Quicksilver within to be four inches above that
+without, I observed the Air to be expanded only 1/7 of an inch more then it
+was at first, and to take up the room of 1-1/7 inch: then I raised the Tube
+till the Cylinder was six inches high, and found the Air to take up 1-2/9
+inches of room in the Pipe; then to 8, 10, 12. &c. the expansion of the Air
+that I found to each of which Cylinders are set down in the following
+Table; where the first row signifies the height of the _Mercurial
+Cylinder_; the next, the expansion of the Air; the third, the pressure of
+the _Atmosphere_, or the highest _Cylinder_ of _Mercury_, which was then
+neer thirty inches: The last signifies the force of the Air so expanded,
+which is found by substracting the first row of numbers out of the third;
+for having found, that the outward Air would then keep up the Quicksilver
+to thirty inches, look whatever of that height is wanting must be
+attributed to the Elater of the Air depressing. And therefore having the
+Expansion in the second row, and the height of the subjacent _Cylinder_ of
+_Mercury_ in the first, and the greatest height of the _Cylinder_ of
+_Mercury_, which of it self counterballances the whole pressure of the
+_Atmosphere_; by substracting the numbers of the first row out of the
+numbers of the third, you will have the measure of the _Cylinders_ so
+deprest, and consequently the force of the Air, in the several Expansions,
+registred.
+
+  The height of the     The Expansion   The height of   The strength
+  Cylinder of Mercury,  of the Air.     the Mercury     of the Elater
+  that, together with                   that counter-   of the expanded
+  the Elater of the                     ballanc'd the   Air.
+  included Air,                         Atmosphere.
+  ballanced the
+  pressure of the
+  Atmosphere.
+   ----------            ----------      ----------      ----------
+      00                    01               30              30
+      02                    01-1/16          30              28
+      04                    01-1/7           30              26
+      06                    01-2/9           30              24
+      08                    01-1/3           30              22
+      10                    01-1/2           30              20
+      12                    01-2/3           30              18
+      14                    01-5/6           30              16
+      16                    02-2/27          30              14
+      18                    02-4/9           30              12
+      20                    03               30              10
+      22                    03-7/9           30               8
+      24                    05-7/18          30               6
+      25                    06-2/3           30               5
+      26                    08-1/2           30               4
+      26-1/4                09-1/2           30               3-3/4
+      26-1/2                10-3/4           30               3-1/2
+      26-3/4                13               30               3-1/4
+      27                    15-1/2           30               3
+
+I had several other Tables of my Observations, and Calculations, which I
+then made; but it being above a twelve month since I made them; and by that
+means having forgot many circumstances and particulars, I was resolved to
+make them over once again, which I did _August_ the second 1661. with the
+very same Tube which I used the year before, when I first made the
+Experiment (for it being a very good one, I had carefully preserv'd it:)
+And after having tryed it over and over again; and being not well satisfied
+of some particulars, I, at last, having put all things in very good order,
+and being as attentive, and observant, as possibly I could, of every
+circumstance requisite to be taken notice of, did register my several
+Observations in this following Table. In the making of which, I did not
+exactly follow the method that I had used at first; but, having lately
+heard of Mr. _Townly_'s _Hypothesis_, I shap'd my course in such sort, as
+would be most convenient for the examination of that _Hypothesis_; the
+event of which you have in the latter part of the last Table.
+
+The other Experiment was, to find what degrees of force were requisite to
+compress, or condense, the Air into such or such a bulk.
+
+The manner of proceeding therein was this: I took a Tube about five foot
+long, one of whose ends was sealed up, and bended in the form of a
+_Syphon_, much like that represented in the fourth Figure of the 37.
+_Scheme_, one side whereof AD, that was open at A, was about fifty inches
+long, the other side BC, shut at B, was not much above seven inches long,
+then placing it exactly perpendicular, I pour'd in a little Quicksilver,
+and found that the Air BC was 6-7/8 inches, or very near to seven; then
+pouring in Quicksilver at the longer Tube, I continued filling of it till
+the Air in the shorter part of it was contracted into half the former
+dimensions, and found the height exactly nine and twenty inches; and by
+making several other tryals, in several other degrees of condensation of
+the Air, I found them exactly answer the former _Hypothesis_.
+
+But having (by reason it was a good while since I first made) forgotten
+many particulars, and being much unsatisfied in others, I made the
+Experiment over again, and, from the several tryals, collected the former
+part of the following Table: Where in the row next the left hand 24.
+signifies the dimensions of the Air, sustaining only the pressure of the
+_Atmosphere_, which at that time was equal to a _Cylinder_ of _Mercury_ of
+nine and twenty inches: The next Figure above it (20) was the dimensions of
+the Air induring the first compression, made by a _Cylinder_ of _Mercury_
+5-3/16 high, to which the pressure of the _Atmosphere_ nine and twenty
+inches being added, the elastick strength of the Air so comprest will be
+found 34-3/16, &c.
+
+_A Table of the Elastick power of the Air, both Experimentally and
+Hypothetically calculated, according to its various Dimensions._
+
+
+  The dimensions   The height    The Mercurial  The sum or  What they
+  of the included  of the        Cylinder       difference  ought to
+  Air.             Mercurial     added, or      of these    be according
+                   Cylinder      taken from     two         to the
+                   counter-      the former.    Cylinders.  Hypothesis.
+                   pois'd
+                   by the
+                   Atmosphere.
+   ----------      ----------     ----------     ----------  ----------
+       12             29      +     29         =   58          58
+       13             29      +     24-11/16   =   53-11/16    53-7/13
+       14             29      +     20-3/16    =   49-3/16     49-5/7
+       16             29      +     14         =   43          43-1/2
+       18             29      +      9-1/8     =   38-1/8      38-2/3
+       20             29      +      5-3/16    =   34-3/16     34-4/5
+       24             29             0         =   29          29
+       48             29      -     14-5/8     =   14-3/8      14-1/2
+       96             29      -     22-1/8     =    6-7/8       7-2/8
+      192             29      -     25-5/8     =    3-3/8       3-5/8
+      384             29      -     27-2/8     =    1-6/8       1-7/16
+      576             29      -     27-7/8     =    1-1/8       1-5/24
+      768             29      -     28-1/8     =    0-7/8       0-[7-1/4]/8
+      960             29      -     28-3/8     =    0-5/8       0-[5-4/5]/8
+     1152             29      -     28-7/16    =    0-9/16      0-10/16
+
+From which Experiments, I think, we may safely conclude, that the Elater of
+the Air is reciprocal to its extension, or at least very neer. So that to
+apply it to our present purpose (which was indeed the chief cause of
+inventing these wayes of tryal) we will suppose a _Cylinder_ indefinitely
+extended upwards, [I say a _Cylinder_, not a piece of a _Cone_, because, as
+I may elsewhere shew in the Explication of Gravity, that _triplicate_
+proportion of the shels of a Sphere, to their respective diameters, I
+suppose to be removed in this case by the decrease of the power of Gravity]
+and the pressure of the Air at the bottom of this _Cylinder_ to be strong
+enough to keep up a _Cylinder_ of _Mercury_ of thirty inches: Now because
+by the most accurate tryals of the most illustrious and incomparable Mr.
+_Boyle_, published in his deservedly famous Pneumatick Book, the weight of
+Quicksilver, to that of the Air here below, is found neer about as fourteen
+thousand to one: If we suppose the parts of the _Cylinder_ of the
+_Atmosphere_ to be every where of an equal density, we shall (as he there
+deduces) find it extended to the height of thirty five thousand feet, or
+seven miles: But because by these Experiments we have somewhat confirm'd
+the hypothesis of the reciprocal proportion of the Elaters to the
+Extensions we shall find, that by supposing this _Cylinder_ of the
+_Atmosphere_ divided into a thousand parts, each of which being equivalent
+to thirty five feet, or seven geometrical paces, that is, each of these
+divisions containing as much Air as is suppos'd in a _Cylinder_ neer the
+earth of equal diameter, and thirty five foot high, we shall find the
+lowermost to press against the surface of the Earth with the whole weight
+of the above mentioned thousand parts; the pressure of the bottom of the
+second against the top of the first to be 1000 - 1 = 999. of the third
+against the second to be 1000 - 2 = 998. of the fourth against the third to
+be 1000 - 3 = 997. of the uppermost against the 999. or that next below it,
+to be 1000 - 999 = 1. so that the extension of the lowermost next the
+Earth, will be to the extension of the next below the uppermost, as 1. to
+999. for as the pressure sustained by the 999. is to the pressure sustain'd
+by the first, so is the extension of the first to the extension of the 999.
+so that, from this hypothetical calculation, we shall find the Air to be
+indefinitely extended: For if we suppose the whole thickness of the Air to
+be divided, as I just now instanced, into a thousand parts, and each of
+those under differing Dimensions, or Altitudes, to contain an equall
+quantity of Air, we shall find, that the first _Cylinder_, whose Base is
+supposed to lean on the Earth, will be found to be extended 35-35/999 foot;
+the second equal Division, or _Cylinder_, whose _basis_ is supposed to lean
+on the top of the first, shall have its top extended higher by 35-70/998
+the third 35-105/997 the fourth 35-140/996 and so onward, each equal
+quantity of Air having its dimensions measured by 35. and some additional
+number exprest alwayes in the manner of a fraction, whose numerator is
+alway the number of the place multipli'd by 35. and whose denominator is
+alwayes the pressure of the _Atmosphere_ sustain'd by that part, so that by
+this means we may easily calculate the height of 999. divisions of those
+1000. divisions, I suppos'd; whereas the uppermost may extend it self more
+then as high again, nay, perhaps indefinitely, or beyond the Moon; for the
+Elaters and Expansions being in reciprocal proportions, since we cannot yet
+find the _plus ultra_, beyond which the Air will not expand it self, we
+cannot determine the height of the Air: for since, as we have shewn, the
+proportion will be alway as the pressure sustain'd by any part is to 35. so
+1000. to the expansion of that part; the multiplication or product
+therefore of the pressure, and expansion, that is, of the two extream
+proportionals, being alwayes equal to the product of the means, or 35000.
+it follows, since that Rectangle or Product may be made up of the
+multiplication of infinite diversities of numbers, that the height of the
+Air is also indefinite; for since (as far as I have yet been able to try)
+the Air seems capable of an indefinite Expansion, the pressure may be
+decreased in _infinitum_, and consequently its expansion upwards indefinite
+also.
+
+There being therefore such a difference of density, and no Experiment yet
+known to prove a _Saltus_, or skipping from one degree of rarity to another
+much differing from it, that is, that an upper part of the Air should so
+much differ from that immediately _subjacent_ to it, as to make a distinct
+superficies, such as we observe between the Air and Water, &c. But it being
+more likely, that there is a continual increase of rarity in the parts of
+the Air, the further they are removed from the surface of the Earth: It
+will hence necessarily follow, that (as in the Experiment of the salt and
+fresh Water) the ray of Light passing obliquely through the Air also, which
+is of very different density, will be continually, and infinitely
+inflected, or bended, from a streight, or direct motion.
+
+This granted, the reason of all the above recited _Phaenomena_, concerning
+the appearance of the Celestial Bodies, will very easily be deduced. As,
+
+First, The redness of the Sun, Moon, and Stars, will be found to be caused
+by the inflection of the rays within the _Atmosphere_. That it is not
+really in or near the luminous bodies, will, I suppose, be very easily
+granted, seeing that this redness is observable in several places differing
+in Longitude, to be at the same time different, the setting and rising Sun
+of all parts being for the most part red:
+
+And secondly, That it is not meerly the colour of the Air interpos'd, will,
+I suppose, without much more difficulty be yielded, seeing that we may
+observe a very great _interstitium_ of Air betwixt the Object, and the Eye,
+makes it appear of a dead blew, far enough differing from a red, or yellow.
+
+But thirdly, That it proceeds from the refraction, or inflection, of the
+rays by the _Atmosphere_, this following Experiment will, I suppose,
+sufficiently manifest.
+
+Take a sphaerical Crystalline Viol, such as is describ'd in the fifth
+Figure ABCD, and, having fill'd it with pure clear Water, expose it to the
+Sun beams; then taking a piece of very fine _Venice_ Paper, apply it
+against that side of the Globe that is opposite to the Sun, as against the
+side BC, and you shall perceive a bright red Ring to appear, caus'd by the
+refraction of the Rays, AAAA, which is made by the Globe; in which
+Experiment, if the Glass and Water be very cleer, so that there be no Sands
+nor bubbles in the Glass, nor dirt in the Water, you shall not perceive any
+appearance of any other colour. To apply which Experiment, we may imagine
+the _Atmosphere_ to be a great transparent Globe, which being of a
+substance more dense then the other, or (which comes to the same) that has
+its parts more dense towards the middle, the Sun beams that are tangents,
+or next within the tangents of this Globe, will be refracted or inflected
+from their direct passage towards the center of the Globe, whence,
+according to the laws of refractions made in a triangular _Prism_, and the
+generation of colour set down in the description of Muscovi-glass there
+must necessarily appear a red colour in the _transitus_ or passage of those
+tangent Rays. To make this more plain, we will suppose (in the sixth
+_Figure_) ABCD, to represent the Globe of the _Atmosphere_, EFGH to
+represent the opacous Globe of the Earth, lying in the midst of it, neer to
+which, the parts of the Air, sustaining a very great pressure, are thereby
+very much condens'd, from whence those Rays that are by inflection made
+tangents to the Globe of the Earth, and those without them, that pass
+through the more condens'd part of the _Atmosphere_, as suppose between A
+and E, are by reason of the inequality of the _medium_, inflected towards
+the center, whereby there must necessarily be generated a red colour, as is
+more plainly shewn in the former cited place; hence whatsoever opacous
+bodies (as vapours, or the like) shall chance to be elevated into those
+parts, will reflect a red towards the eye; and therefore those evenings and
+mornings appear reddest, that have the most store of vapours and halituous
+substances exhaled to a convenient distance from the Earth; for thereby the
+inflection is made the greater, and thereby the colour also the more
+intense; and several of those exhalations being opacous, reflect several of
+those Rays, which, through an _Homogeneous_ transparent _medium_ would pass
+unseen; and therefore we see, that when there chances to be any clouds
+situated in those Regions they reflect a strong and vivid red. Now, though
+one great cause of the redness may be this inflection, yet I cannot wholly
+exclude the colour of the vapours themselves, which may have something of
+redness in them, they being partly nitrous; and partly fuliginous; both
+which steams tinge the Rays that pass through them, as is made evident by
+looking at bodies through the fumes of _Aqua fortis_ or spirit of _Nitre_
+[as the newly mentioned Illustrious Person has demonstrated] and also
+through the smoak of a Fire or Chimney.
+
+Having therefore made it probable at least, that the morning and evening
+redness may partly proceed from this inflection or refraction of the Rays,
+we shall next shew how the Oval Figure will be likewise easily deduced.
+
+Suppose we therefore, EFGH in the sixth _Figure_ of the 37. _Scheme_, to
+represent the Earth; ABCD, the _Atmosphere_; EI, and EL, two Rays coming
+from the Sun, the one from the upper, the other from the neather Limb,
+these Rays, being by the _Atmosphere_ inflected, appear to the eye at E, as
+if they had come from the points, N and O; and because the Ray L has a
+greater inclination upon the inequality of the _Atmosphere_ then I,
+therefore must it suffer a greater inflection, and consequently be further
+elevated above its true place, then the Ray I, which has a less
+inclination, will be elevated above its true place; whence it will follow,
+that the lower side appearing neerer the upper then really it is, and the
+two _lateral_ sides, _viz._ the right and left side, suffering no sensible
+alteration from the inflection, at least what it does suffer, does rather
+increase the visible Diameter then diminish it, as I shall shew by and by,
+the Figure of the luminous body must necessarily appear somewhat
+_Elliptical_.
+
+This will be more plain, if in the seventh _Figure_ of the 37. _Scheme_ we
+suppose AB to represent the sensible Horizon; CDEF, the body of the Sun
+really below it; GHIK, the same appearing above it, elevated by the
+inflection of the _Atmosphere_: For if, according to the best observation,
+we make the visible Diameter of the Sun to be about three or four and
+thirty minutes, and the Horizontal refraction according to _Ticho_ be
+thereabout, or somewhat more, the lower limb of the Sun E, will be elevated
+to I; but because, by his account, the point C will be elevated but 29.
+minutes, as having not so great an inclination upon the inequality of the
+Air, therefore IG, which will be the apparent refracted perpendicular
+Diameter of the Sun, will be less then CG, which is but 29. minutes, and
+consequently six or seven minutes shorter then the unrefracted apparent
+Diameter. The parts, D and F, will be likewise elevated to H and K, whose
+refraction, by reason of its inclination, will be bigger then that of the
+point C, though less then that of E; therefore will the semidiameter IL, be
+shorter then LG, and consequently the under side of the appearing Sun more
+flat then the upper.
+
+Now, because the Rays from the right and left sides of the Sun, &c. have
+been observ'd by _Ricciolo_ and _Grimaldus_, to appear more distant one
+from another then really they are, though (by very many Observations that I
+have made for that purpose, with a very good _Telescope_, fitted with a
+divided Ruler) I could never perceive any great alteration, yet there being
+really some, it will not be amiss, to shew that this also proceeds from the
+refraction or inflection of the _Atmosphere_; and this will be manifest, if
+we consider the _Atmosphere_ as a transparent Globe, or at least a
+transparent shell, encompassing an opacous Globe, which, being more dense
+then the _medium_ encompassing it, refracts or inflects all the entring
+parallel Rays into a point or focus, so that wheresoever the Observator is
+plac'd within the _Atmosphere_, between the focus and the luminous body,
+the _lateral_ Rays must necessarily be more converg'd towards his eye by
+the refraction or inflection, then they would have been without it; and
+therefore the Horizontal Diameter of the luminous body must necessarily be
+augmented.
+
+This might be more plainly manifest to the eye by the sixth _Figure_; but
+because it would be somwhat tedious, and the thing being obvious enough to
+be imagin'd by any one that attentively considers it, I shall rather omit
+it, and proceed to shew, that the mass of Air neer the surface of the
+Earth, consists, or is made up, of parcels, which do very much differ from
+one another in point of density and rarity; and consequently the Rays of
+light that pass through them will be variously inflected, here one way, and
+there another, according as they pass so or so through those differing
+parts; and those parts being always in motion, either upwards or downwards,
+or to the right or left, or in some way compounded of these, they do by
+this their motion inflect the Rays, now this way, and presently that way.
+
+This irregular, unequal and unconstant inflection of the Rays of light, is
+the reason why the limb of the _Sun_, _Moon_, _Jupiter_, _Saturn_, _Mars_,
+and _Venus_, appear to wave or dance; and why the body of the Starrs appear
+to tremulate or twinkle, their bodies, by this means, being sometimes
+magnify'd, and sometimes diminished; sometimes elevated, otherwhiles
+depress'd; now thrown to the right hand, and then to the left.
+
+And that there is such a property or unequal distribution of parts, is
+manifest from the various degrees of heat and cold that are found in the
+Air; from whence will follow a differing density and rarity, both as to
+quantity and refraction; and likewise from the vapours that are interpos'd,
+(which, by the way, I imagine, as to refraction or inflection, to do the
+same thing, as if they were rarify'd Air; and that those vapours that
+ascend, are both lighter, and less dense, then the ambient Air which boys
+them up; and that those which descend, are heavier and more dense) The
+first of these may be found true, if you take a good thick piece of Glass,
+and heating it pretty hot in the fire, lay it upon such another piece of
+Glass, or hang it in the open Air by a piece of Wire, then looking upon
+some far distant Object (such as a Steeple or Tree) so as the Rays from
+that Object pass directly over the Glass before they enter your eye, you
+shall find such a tremulation and wavering of the remote Object, as will
+very much offend your eye: The like tremulous motion you may observe to be
+caus'd by the ascending steams of Water, and the like. Now, from the first
+of these it is manifest, that from the rarifaction of the parts of the Air,
+by heat, there is caus'd a differing refraction, and from the ascension of
+the more rarify'd parts of the Air, which are thrust up by the colder, and
+therefore more condens'd and heavie, is caus'd an undulation or wavering of
+the Object; for I think, that there are very few will grant, that Glass, by
+as gentle a heat as may be endur'd by ones hand, should send forth any of
+its parts in steams or vapours, which does not seem to be much wasted by
+that violent fire of the green Glass-house; but, if yet it be doubted, let
+Experiment be further made with that body that is accounted, by Chymists
+and others, the most ponderous and fix'd in the world; for by heating of a
+piece of Gold, and proceeding in the same manner, you may find the same
+effects.
+
+This trembling and shaking of the Rays, is more sensibly caus'd by an
+actual flame, or quick fire, or anything else heated glowing hot; as by a
+Candle, live Coal, red-hot Iron, or a piece of Silver, and the like: the
+same also appears very conspicuous, if you look at an Object betwixt which
+and your eye, the rising smoak of some Chimney is interpos'd; which brings
+into my mind what I had once the opportunity to observe, which was, the Sun
+rising to my eye just over a Chimney that sent forth a copious steam of
+smoak; and taking a short _Telescope_, which I had then by me, I observ'd
+the body of the Sun, though it was but just peep'd above the Horizon, to
+have its underside, not onely flatted, and press'd inward, as it usually is
+when neer the Earth; but to appear more protuberant downwards then if it
+had suffered no refraction at all; and besides all this, the whole body of
+the Sun appear'd to tremble or dance, and the edges or limb to be very
+ragged or indented, undulating or waving, much in the manner of a flag in
+the Wind.
+
+This I have likewise often observ'd in a hot Sunshiny Summer's day, that
+looking on an Object over a hot stone, or dry hot earth, I have found the
+Object to be undulated or shaken, much after the same manner. And if you
+look upon any remote Object through a _Telescope_ (in a hot Summer's day
+especially) you shall find it likewise to appear tremulous. And further, if
+there chance to blow any wind, or that the air between you and the Object
+be in a motion or current, whereby the parts of it, both rarify'd and
+condens'd, are swiftly remov'd towards the right or left, if then you
+observe the Horizontal ridge of a Hill far distant, through a very good
+_Telescope_, you shall find it to wave much like the Sea, and those waves
+will appear to pass the same way with the wind.
+
+From which, and many other Experiments, 'tis cleer that the lower Region of
+the Air, especially that part of it which lieth neerest to the Earth, has,
+for the most part, its constituent parcels variously agitated, either by
+heat or winds, by the first of which, some of them are made more rare, and
+so suffer a less refraction; others are interwoven, either with ascending
+or descending vapours; the former of which being more light, and so more
+rarify'd, have likewise a less refraction; the latter being more heavie,
+and consequently more dense, have a greater.
+
+Now, because that heat and cold are equally diffus'd every way; and that
+the further it is spread, the weaker it grows; hence it will follow, that
+the most part of the under Region of the Air will be made up of several
+kinds of _lentes_, some whereof will have the properties of _Convex_,
+others of _Concave_ _glasses_, which, that I may the more intelligibly make
+out, we will suppose in the eighth _Figure_ of the 37. _Scheme_, that A
+represents an ascending vapour, which, by reason of its being somewhat
+_Heterogeneous_ to the ambient Air, is thereby thrust into a kind of
+Globular form, not any where terminated, but gradually finished, that is,
+it is most rarify'd in the middle about A. somewhat more condens'd about
+BB, more then that about CC; yet further, about DD, almost of the same
+density with the ambient Air about EE;, and lastly, inclosed with the more
+dense Air FF, so that from A, to FF, there is a continual increase of
+density. The reason of which will be manifest, if we consider the rising
+vapour to be much warmer then the ambient heavie Air; for by the coldness
+of the ambient Air, the shell EE will be more refrigerated then DD, and
+that then CC, which will be yet more then BB, and that more then A; so that
+from F to A, there is a continual increase of heat, and consequently of
+rarity; from whence it will necessarily follow, that the Rays of light will
+be inflected or refracted in it, in the same manner as they would be in a
+_Concave-glase_; for the Rays _GKI_, _GKI_ will be inflected by _GKH_,
+_GKH_, which will easily follow from what I before explained concerning the
+inflection of the _Atmosphere_.
+
+On the other side, a descending vapour, or any part of the air included by
+an ascending vapour, will exhibit the same effects with a _Convex lens_;
+for, if we suppose, in the former Figure, the quite contrary constitution
+to that last describ'd; that is, the ambient Air FF being hotter then any
+part of that matter within any circle, therefore the coldest part must
+necessarily be A, as being farthest remov'd from the heat, all the
+intermediate spaces will be gradually discriminated by the continuall
+mixture of heat and cold, so that it will be hotter at EE, then DD, in DD
+then CC, in CC then BB, and in BB then A. From which, a like refraction and
+condensation will follow, and consequently a lesser or greater refraction,
+so that every included part will refract more then the including, by which
+means the Rays, GKI, GKI, coming from a Starr, or some remote Object, are
+so inflected, that they will again concurr and meet, in the point M. By the
+interposition therefore of this desending vapour the visible body of the
+Star, or other Object, is very much augmented, as by the former it was
+diminished.
+
+From the quick consecutions of these two, one after another, between the
+Object and your eye, caused by their motion upwards or downwards,
+proceeding from their levity or gravity, or to the right or left,
+proceeding from the wind, a Starr may appear, now bigger, now less, then
+really it would otherwise without them; and this is that property of a
+Starr, which is commonly call'd twinkling, or scintillation.
+
+The reason why a Star will now appear of one colour, now of another, which
+for the most part happens when 'tis neer the Horizon, may very easily be
+deduc'd from its appearing now in the middle of the vapour, other whiles
+neer the edge; for if you look against the body of a Starr with a
+_Telescope_ that has a pretty deep _Convex_ Eye-glass, and so order it,
+that the Star may appear sometimes in one place, and sometimes in another
+of it; you may perceive this or that particular colour to be predominant in
+the apparent Figure of the Starr, according as it is more or less remote
+from the middle of the _Lens_. This I had here further explain'd, but that
+it does more properly belong to another place.
+
+I shall therefore onely add some few Queries, which the consideration of
+these particulars hinted, and so finish this Section.
+
+And the first I shall propound is, Whether there may not be made an
+artificial transparent body of an exact Globular Figure that shall so
+inflect or refract all the Rays, that, coming from one point, fall upon any
+_Hemisphere_ of it; that every one of them may meet on the opposite side,
+and cross one another exactly in a point; and that it may do the like also
+with all the Rays that, coming from a _lateral_ point, fall upon any other
+_Hemisphere_; for if so, there were to be hoped a perfection of
+_Dioptricks_, and a transmigration into heaven, even whil'st we remain here
+upon earth in the flesh, and a descending or penetrating into the center
+and innermost recesses of the earth, and all earthly bodies; nay, it would
+open not onely a cranney, but a large window (as I may so speak) into the
+Shop of Nature, whereby we might be enabled to see both the tools and
+operators, and the very manner of the operation it self of Nature; this,
+could it be effected, would as farr surpass all other kind of perspectives
+as the vast extent of Heaven does the small point of the Earth, which
+distance it would immediately remove, and unite them, as 'twere, into one,
+at least, that there should appear no more distance between them then the
+length of the Tube, into the ends of which these Glasses should be
+inserted: Now, whether this may not be effected with parcels of Glass of
+several densities, I have sometimes proceeded so farr as to doubt (though
+in truth, as to the general, I have wholly despair'd of it) for I have
+often observ'd in Optical Glasses a very great variety of the parts, which
+are commonly called Veins; nay, some of them round enough (for they are for
+the most part, drawn out into firings) to constitute a kind of _lens_.
+
+This I should further proceed to hope, had any one been so inquisitive as
+to have found out the way of making any transparent body, either more dense
+or more rare, for then it might be possible to compose a Globule that
+should be more dense in the middle of it, then in any other part, and to
+compose the whole bulk, so as that there should be a continual gradual
+transition from one degree of density to another; such as should be found
+requisite for the desired inflection of the _transmigrating_ Rays; but of
+this enough at present, because I may say more of it when I set down my own
+Trials concerning the melioration of _Dioptricks_, where I shall enumerate
+with how many several substances I have made both _Microscopes_, and
+_Telescopes_, and by what and how many, ways: Let such as have leisure and
+opportunity farther consider it.
+
+The next Quaery shall be, whether by the same collection of a more dense
+body then the other, or at least, of the denser part of the other, there
+might not be imagin'd a reason of the apparition of some new fix'd Stars,
+as those in the Swan, _Cassiope's Charr_, _Serpentarius_, _Piscis_,
+_Cetus_, &c.
+
+Thirdly, Whether it be possible to define the height of the _Atmosphere_
+from this inflection of the Rays, or from the Quicksilver Experiment of the
+rarifaction or extension of the Air.
+
+Fourthly, Whether the disparity between the upper and under Air be not
+sometimes so great, as to make a reflecting superficies; I have had several
+Observations which seem to have proceeded from some such cause, but it
+would be too long to relate and examine them. An Experiment, also somewhat
+analogous to this, I have made with Salt-water and Fresh, which two
+liquors, in most Positions, seem'd the same, and not to be separated by any
+determinate superficies, which separating surface yet in some other
+Positions did plainly appear.
+
+And if so, Whether the reason of the equal bounding or _terminus_ of the
+under parts of the clouds may not proceed from this cause; whether,
+secondly, the Reason of the apparition of many Suns may not be found out,
+by considering how the Rays of the Sun may so be reflected, as to describe
+a pretty true Image of the body, as we find them from any regular
+Superficies. Whether also this may not be found to cause the apparition of
+some of those _Parelii_, of counterfeit Suns, which appear coloured, by
+refracting the Rays so, as to make the body of the Sun appear in quite
+another place then really it is. But of this more elsewhere.
+
+5. Whether the _Phaenomena_ of the Clouds may not be made out by this
+diversity of density in the upper and under parts of the Air, by supposing
+the Air above them to be much lighter then they themselves are, and they
+themselves to be yet lighter then that which is subjacent to them, many of
+them seeming to be the same substance with the Cobwebs that fly in the Air
+after a Fog.
+
+Now that such a constitution of the Air and Clouds, if such there be, may
+be sufficient to perform this effect, may be confirm'd by this Experiment.
+
+Make as strong a Solution of Salt as you are able, then filling a Glass of
+some depth half full with it, fill the other half with fresh Water, and
+poyse a little Glass-bubble, so as that it may sink pretty quick in fresh
+Water, which take and put into the aforesaid Glass, and you shall find it
+to sink till it comes towards the middle, where it will remain fixt,
+without moving either upwards or downwards. And by a second Experiment, of
+poising such a bubble in water, whose upper part is warmer, and
+consequently lighter, then the under, which is colder and heavier; the
+manner of which follows in this next Quaery, which is,
+
+6. Whether the rarifaction and condensation of Water be not made after the
+same manner, as those effects are produc'd in the Air by heat; for I once
+pois'd a seal'd up Glass-bubble so exactly, that never so small an addition
+would make it sink, and as small a detraction make it swim, which suffering
+to rest in that Vessel of Water for some time, I alwayes found it about
+noon to be at the bottom of the Water, and at night, and in the morning, at
+the top: Imagining this to proceed from the Rarifaction of the Water,
+caus'd by the heat, I made tryal, and found most true; for I was able at
+any time, either to depress, or raise it, by heat and cold; for if I let
+the Pipe stand for some time in cold water, I could easily raise the Bubble
+from the bottom, whither I had a little afore detruded it, by putting the
+same Pipe into warm Water. And this way I have been able, for a very
+considerable time, to keep a Bubble so poys'd in the Water, as that it
+should remain in the middle, and neither sink, nor swim: For gently heating
+the upper part of the Pipe with a Candle, Coal, or hot Iron, till I
+perceived the Bubble begin to descend, then forbearing, I have observed it
+to descend to such or such a station, and there to remain suspended for
+some hours, till the heat by degrees were quite vanished, when it would
+again ascend to its former place. This I have also often observed naturally
+performed by the heat of the Air, which being able to rarifie the upper
+parts of the Water sooner then the lower, by reason of its immediate
+contact, the heat of the Air has sometimes so slowly increased, that I have
+observed the Bubble to be some hours in passing between the top and bottom.
+
+7. Whether the appearance of the _Pike_ of _Tenerif_, and several other
+high Mountains, at so much greater a distance then seems to agree with
+their respective heights, be not to be attributed to the _Curvature_ of the
+visual Ray, that is made by its passing obliquely through so differingly
+_Dense_ a Medium from the top to the eye very far distant in the Horizon:
+For since we have already, I hope, made it very probable, that there is
+such an _inflection_ of the Rays by the differing density of the parts of
+the Air; and since I have found, by several Experiments made on places
+comparatively not very high, and have yet found the pressure sustain'd by
+those parts of the Air at the top and bottom, and also their differing
+Expansions very considerable: Insomuch that I have found the pressure of
+the _Atmosphere_ lighter at the top of St. _Paul_'s Steeple in _London_
+(which is about two hundred foot high) then at the bottom by a sixtieth or
+fiftieth part, and the expansion at the top greater then that at the bottom
+by neer about so much also; for the _Mercurial Cylinder_ at the bottom was
+about 39. inches, and at the top half an inch lower; the Air also included
+in the Weather-glass, that at the bottom fill'd only 155. spaces, at the
+top fill'd 158. though the heat at the top and bottom was found exactly the
+same with a scal'd _Thermometer_: I think it very rational to suppose, that
+the greatest Curvature of the Rays is made nearest the Earth, and that the
+inflection of the Rays, above 3. or 4. miles upwards, is very
+inconsiderable, and therefore that by this means such calculations of the
+height of Mountains, as are made from the distance they are visible in the
+Horizon, from the supposal that that Ray is a straight Line (that from the
+top of the Mountain is, as 'twere, a Tangent to the Horizon whence it is
+seen) which really is a _Curve_, is very erroneous. Whence, I suppose,
+proceeds the reason of the exceedingly differing Opinions and Assertions of
+several Authors, about the height of several very high Hills.
+
+8. Whether this Inflection of the Air will not very much alter the supposed
+distances of the Planets, which seem to have a very great dependence upon
+the Hypothetical refraction or inflection of the Air, and that refraction
+upon the hypothetical height and density of the Air: For since (as I hope)
+I have here shewn the Air to be quite otherwise then has been hitherto
+suppos'd, by manifesting it to be, both of a vast, at least an uncertain,
+height, and of an unconstant and irregular density; It must necessarily
+follow, that its inflection must be varied accordingly: And therefore we
+may hence learn, upon what sure grounds all the Astronomers hitherto have
+built, who have calculated the distance of the Planets from their
+Horizontal _Parallax_; for since the Refraction and _Parallax_ are so
+nearly ally'd, that the one cannot be known without the other, especially
+by any wayes that have been yet attempted, how uncertain must the
+_Parallax_ be, when the Refraction is unknown? And how easie is it for
+Astronomers to assign what distance they please to the Planets, and defend
+them, when they have such a curious _subterfuge_ as that of Refraction,
+wherein a very little variation will allow them liberty enough to place the
+Celestial Bodies at what distance they please.
+
+If therefore we would come to any certainty in this point, we must go other
+wayes to work; and as I have here examined the height and refractive
+property of the Air by other wayes then are usual, so must we find the
+Parallax of the Planets by wayes not yet practiced; and to this end, I
+cannot imagine any better way, then the Observations of them by two persons
+at very far distant parts of the Earth, that lye as neer as may be under
+the same Meridian, or Degree of longitude, but differing as much in
+latitude, as there can be places conveniently found: These two persons, at
+certain appointed times, should (as near as could be) both at the same
+time, observe the way of the _Moon_, _Mars_, _Venus_, _Jupiter_, and
+_Saturn_, amongst the fixt Stars, with a good large _Telescope_, and making
+little Iconismes, or pictures, of the small fixed Stars, that appear to
+each of them to lye in or near the way of the Center of the Planet, and the
+exact measure of the apparent Diameter; from the comparing of such
+Observations together, we might certainly know the true distance, or
+Parallax, of the Planet. And having any one true Parallax of these Planets,
+we might very easily have the other by their apparent Diameters, which the
+_Telescope_ likewise affords us very accurately. And thence their motions
+might be much better known, and their Theories more exactly regulated. And
+for this purpose I know not any one place more convenient for such an
+Observation to be made in, then in the Island of St. _Helena_, upon the
+Coast of _Africk_, which lyes about sixteen degrees to the Southwards of
+the Line, and is very near, according to the latest Geographical Maps, in
+the same Meridian with _London_; for though they may not perhaps lye
+exactly in the same, yet their Observations, being ordered according to
+what I shall anon shew, it will not be difficult to find the true distance
+of the Planet. But were they both under the same Meridian, it would be much
+better.
+
+And because Observations may be much easier, and more accurately made with
+good _Telescopes_, then with any other Instruments, it will not, I suppose,
+seem impertinent to explain a little what wayes I judge most fit and
+convenient for that particular. Such therefore as shall be the Observators
+for this purpose, should be furnished with the best _Telescopes_ that can
+be had, the longer the better and more exact will their Observations be,
+though they are somewhat the more difficultly manag'd. These should be
+fitted with a _Rete_, or divided Scale, plac'd at such a distance within
+the Eye-glass, that they may be distinctly seen, which should be the
+measures of minutes and seconds; by this Instrument each Observator should,
+at certain prefixt times, observe the Moon, or other Planet, in, or very
+near, the Meridian; and because it may be very difficult to find two
+convenient stations that will happen to be just under the same Meridian,
+they shall, each of them, observe the way of the Planet, both for an hour
+before, and an hour after, it arrive at the Meridian; and by a line, or
+stroke, amongst the small fixed Stars, they shall denote out the way that
+each of them observ'd the Center of the Planet to be mov'd in for those two
+hours: These Observations each of them shall repeat for many dayes
+together, that both it may happen, that both of them may sometimes make
+their Observations together, and that from divers Experiments we may be the
+better assured of what certainty and exactness such kind of Observations
+are like to prove. And because many of the Stars which may happen to come
+within the compass of such an _Iconism_, or Map, may be such as are only
+visible through a good _Telescope_, whose Positions perhaps have not been
+noted, nor their longitudes, or latitudes, any where remarked; therefore
+each Observator should indeavour to insert some fixt Star, whose longitude,
+and latitude, is known; or with his _Telescope_ he shall find the Position
+of some notable _telescopical_ Star, inserted in his Map, to some known
+fixt Star, whose place in the _Zodiack_ is well defin'd.
+
+Having by this means found the true distance of the Moon, and having
+observed well the _apparent Diameter_ of it at that time with a good
+_Telescope_, it is easie enough, by one single Observation of the apparent
+Diameter of the Moon with a good Glass, to determine her distances in any
+other part of her _Orbit_, or _Dragon_, and consequently, some few
+Observations will tell us, whether she be mov'd in an _Ellipsis_, (which,
+by the way, may also be found, even now, though I think we are yet ignorant
+of her true distance) and next (which without such Observations, I think,
+we shall not be sure of) we may know exactly the bigness of that
+_Ellipsis_, or Circle, and her true velocity in each part, and thereby be
+much the better inabled to find out the true cause of all her Motions. And
+though, even now also, we may, by such Observations in one station, as here
+at _London_, observe the _apparent Diameter_ and motion of the Moon in her
+_Dragon_, and consequently be inabled to make a better ghess at the
+_Species_ or kind of Curve, in which she is mov'd, that is, whether it be
+sphaerical, or _elliptical_, or neither, and with what proportional
+velocities she is carried in that Curve; yet till her true _Parallax_ be
+known, we cannot determine either.
+
+Next, for the true distance of the Sun, the best way will be, by accurate
+Observations, made in both these forementioned stations, of some convenient
+Eclipse of the Sun, many of which may so happen, as to be seen by both; for
+the _Penumbra_ of the Moon may, if she be sixty Semidiameters distant from
+the Earth, and the Sun above seven thousand, extend to about seventy
+degrees on the Earth, and consequently be seen by Observators as far
+distant as _London_, and St. _Helena_, which are not full sixty nine
+degrees distant. And this would much more accurately, then any way that has
+been yet used, determine the Parallax, and distance, of the Sun; for as for
+the Horizontal Parallax I have already shewn it sufficiently uncertain; nor
+is the way of finding it by the Eclipse of the Moon any other then
+hypothetical; and that by the difference of the true and apparent
+quadrature of the Moon is not less uncertain, witness their Deductions from
+it, who have made use of it; for _Vendeline_ puts that difference to be but
+4'.30". whence he deduces a vast distance of the Sun, as I have before
+shewn. _Ricciolo_ makes it full 30'.00. but _Reinoldus_, and _Kircher_, no
+less then three degrees. And no wonder, for if we examine the _Theory_, we
+shall find it so complicated with uncertainties.
+
+First, From the irregular surface of the Moon, and from several Parallaxes,
+that unless the _Dichotomy_ happen in the _Nonagesimus_ of the _Ecliptick_,
+and that in the Meridian, &c. all which happen so very seldom, that it is
+almost impossible to make them otherwise then uncertainly. Besides, we are
+not yet certain, but that there may be somewhat about the Moon _analogus_
+to the Air about the Earth, which may cause a refraction of the light of
+the Sun, and consequently make a great difference in the apparent
+_dichotomy_ of the Moon. Their way indeed is very rational and ingenious;
+and such as is much to be preferred before the way by the Horizontal
+Parallax, could all the uncertainties be remov'd, and were the true
+distance of the Moon known.
+
+But because we find by the Experiments of _Vendiline_, _Reinoldus_, &c.
+that Observations of this kind are very uncertain also: It were to be
+wisht, that such kind of Observations, made at two very distant stations,
+were promoted. And it is so much the more desirable, because, from what I
+have now shewn of the nature of the Air, it is evident, that the refraction
+may be very much greater then all the Astronomers hitherto have imagined
+it: And consequently, that the distance of the Moon, and other Planets, may
+be much lesse then what they have hitherto made it.
+
+For first, this Inflection, I have here propounded, will allow the shadow
+of the Earth to be much shorter then it can be made by the other
+_Hypothesis_ of refraction, and consequently, the Moon will not suffer an
+Eclipse, unless it comes very much nearer the Earth then the Astronomers
+hitherto have supposed it.
+
+Secondly, There will not in this _Hypothesis_ be any other shadow of the
+Earth, such as _Kepler_ supposes, and calls the _Penumbra_, which is the
+shadow of the refracting _Atmosphere_; for the bending of the Rays being
+altogether caus'd by _Inflection_, as I have already shewn, all that part
+which is ascribed by _Kepler_, and others after him, to the _Penumbra_, or
+dark part, which is without the _umbra terrae_, does clear vanish; for in
+this _Hypothesis_ there is no refracting surface of the Air, and
+consequently there can be no shadows, such as appear in the ninth Figure of
+the 37. _Scheme_, where let ABCD represent the Earth, and EFGH the
+_Atmosphere_, which according to _Keplers_ supposition, is like a Sphaere
+of Water terminated with an exact surface EFGH, let the lines MF, LB, ID,
+KH, represent the Rays of the Sun; 'tis manifest, that all the Rayes
+between LB, and ID, will be reflected by the surface of the Earth BAD, and
+consequently, the conical space BOD would be dark and obscure; but, say the
+followers of _Kepler_, the Rays between MF, and LB, and between ID, and KH,
+falling on the _Atmosphere_, are refracted, both at their ingress and
+egress out of the _Atmosphere_, nearer towards the Axis of the sphaerical
+shadow CO, and consequently, inlighten a great part of that former dark
+Cone, and shorten, and contract, its top to N. And because of this
+Reflection of these Rays, say they, there is superinduc'd another shell of
+a dark Cone FPH, whose Apex P is yet further distant from the Earth: By
+this _Penumbra_, say they, the Moon is Eclipsed, for it alwayes passes
+between the lines 12, and 34.
+
+To which I say, That if the Air be such, as I have newly shewn it to be,
+and consequently cause such an inflection of the Rays that fall into it,
+those dark _Penumbra's_ FYZQ, HXVT, and ORPS, will all vanish. For if we
+suppose the Air indefinitely extended, and to be no where bounded with a
+determinate refracting surface, as I have shewn it uncapable of having,
+from the nature of it; it will follow, that the Moon will no where be
+totally obscured, but when it is below the Apex N, of the dark blunt Cone
+of the Earth's shadow: Now, from the supposition, that the Sun is distant
+about seven thousand Diameters, the point N, according to calculation,
+being not above twenty five terrestrial Semidiameters from the Center of
+the Earth: It follows, that whensoever the Moon eclipsed is totally
+darkned, without affording any kind of light, it must be within twenty five
+Semidiameters of the Earth, and consequently much lower then any
+Astronomers have hitherto put it.
+
+This will seem much more consonant to the rest of the secundary Planets;
+for the highest of _Jupiter's_ Moons is between twenty and thirty _Jovial
+Semidiameters_ distant from the Center of _Jupiter_; and the Moons of
+_Saturn_ much about the same number of _Saturnial Semidiameters_ from the
+Center of that Planet.
+
+But these are but conjectures also, and must be determin'd by such kind of
+Observations as I have newly mention'd.
+
+Nor will it be difficult, by this _Hypothesis_, to salve all the
+appearances of Eclipses of the Moon, for in this _Hypothesis_ also, there
+will be on each side of the shadow of the Earth, a _Penumbra_, not caus'd
+by the Refraction of the Air, as in the _Hypothesis_ of _Kepler_; but by
+the faint inlightning of it by the Sun: For if, in the sixth Figure, we
+suppose ESQ, and GSR, to be the Rays that terminate the shadow from either
+side of the Earth; ESQ coming from the upper limb of the Sun, and GSR from
+the under; it will follow, that the shadow of the Earth, within those Rays,
+that is, the Cone GSE, will be totally dark. But the Sun being not a point,
+but a large _area_ of light, there will be a secondary dark Cone of shadow
+EPG, which will be caus'd by the earth's hindring part of the Rays of the
+Sun from falling on the parts GPR, and EPQ, of which halved shadow, or
+_Penumbra_, that part will appear brightest which lyes nearest the
+terminating Rayes GP, and EP, and those darker that lye nearest to GS, and
+ES: when therefore the Moon appears quite dark in the middle of the
+Eclipse, she must be below S, that is, between S and F; when she appears
+lighter near the middle of the Eclipse, she must pass some where between RQ
+and S; and when she is alike light through the whole Eclypse, she must pass
+between RQ, and P.
+
+       *       *       *       *       *
+
+
+Observ. LIX. _Of multitudes of small _Stars_ discoverable by the
+_Telescope_._
+
+Having, in the last Observation, premis'd some particulars observable in
+the _medium_, through which we must look upon _Coelestial_ Objects, I shall
+here add one Observation of the Bodies themselves; and for a _specimen_ I
+have made choice of the _Pleiades_, or seven Stars, commonly so called
+(though in our time and Climate there appear no more then six to the naked
+eye) and this I did the rather, because the deservedly famous _Galileo_,
+having publisht a Picture of this _Asterisme_, was able, it seems, with his
+Glass to discover no more then thirty six, whereas with a pretty good
+twelve foot _Telescope_, by which I drew this 38 _Iconism_, I could very
+plainly discover seventy eight, placed in the order they are ranged in the
+Figure, and of as many differing Magnitudes as the _Asterisks_, wherewith
+they are Marked, do specifie; there being no less then fourteen several
+Magnitudes of those Stars, which are compris'd within the draught, the
+biggest whereof is not accounted greater then one of the third Magnitude;
+and indeed that account is much too big, if it be compared with other Stars
+of the third Magnitude, especially by the help of a _Telescope_; for then
+by it may be perceiv'd, that its splendor, to the naked eye, may be
+somewhat augmented by the three little Stars immediately above it, which
+are near adjoyning to it. The _Telescope_ also discovers a great variety,
+even in the bigness of those, commonly reckon'd, of the first, second,
+third, fourth, fifth, and sixth Magnitude; so that should they be
+distinguish'd thereby, those six Magnitudes would, at least, afford no less
+then thrice that number of Magnitudes, plainly enough distinguishable by
+their Magnitude, and brightness; so that a good twelve foot Glass would
+afford us no less then twenty five several Magnitudes. Nor are these all,
+but a longer Glass does yet further, both more nicely distinguish the
+Magnitudes of those already noted, and also discover several other of
+smaller Magnitudes, not discernable by the twelve foot Glass: Thus have I
+been able, with a good thirty six foot Glass, to discover many more Stars
+in the _Pleiades_ then are here delineated, and those of three or four
+distinct Magnitudes less then any of those spots of the fourteenth
+Magnitude. And by the twinkling of divers other places of this _Asterisme_,
+when the Sky was very clear, I am apt to think, that with longer Glasses,
+or such as would bear a bigger _aperture_, there might be discovered
+multitudes of other small Stars, yet inconspicuous. And indeed, for the
+discovery of small Stars, the bigger the _aperture_ be, the better adapted
+is the Glass; for though perhaps it does make the several specks more
+radiant, and glaring, yet by that means, uniting more Rays very near to one
+point, it does make many of those radiant points conspicuous, which, by
+putting on a less _aperture_, may be found to vanish; and therefore, both
+for the discovery of the fixt Star, and for finding the _Satellites_ of
+_Jupiter_, before it be out of the day, or twilight, I alwayes leave the
+Object-glass as clear without any _aperture_ as I can, and have thereby
+been able to discover the _Satellites_ a long while before; I was able to
+discern them, when the smaller _apertures_ were put on; and at other times,
+to see multitudes of other smaller Stars, which a smaller _aperture_ makes
+to disappear.
+
+In that notable _Asterism_ also of the Sword of _Orion_, where the
+ingenious Monsieur _Hugens van Zulichem_ has discovered only three little
+Stars in a cluster, I have with a thirty six foot Glass, without any
+_aperture_ (the breadth of the Glass being about some three inches and a
+half) discover'd five, and the twinkling of divers others up and down in
+divers parts of that small milky Cloud.
+
+So that 'tis not unlikely, but that the meliorating of _Telescopes_ will
+afford as great a variety of new Discoveries in the Heavens, as better
+_Microscopes_ would among small terrestrial Bodies, and both would give us
+infinite cause, more and more to admire the omnipotence of the Creator.
+
+       *       *       *       *       *
+
+
+Observ. LX. _Of the _Moon_._
+
+Having a pretty large corner of the Plate for the seven Starrs, void, for
+the filling it up, I have added one small _Specimen_ of the appearance of
+the parts of the Moon, by describing a small spot of it, which, though
+taken notice of, both by the Excellent _Hevelius_, and called _Mons
+Olympus_ (though I think somewhat improperly, being rather a vale) and
+represented by the Figure X. of the 38. _Scheme_, and also by the Learn'd
+_Ricciolus_, who calls it _Hipparchus_, and describes it by the Figure Y,
+yet how far short both of them come of the truth, may be somewhat perceiv'd
+by the draught, which I have here added of it, in the Figure Z, (which I
+drew by a thirty foot Glass, in _October_ 1664. just before the Moon was
+half inlightned) but much better by the Reader's diligently observing it
+himself, at a convenient time, with a Glass of that length, and much better
+yet with one of threescore foot long, for through these it appears a very
+spacious Vale, incompassed with a ridge of Hills, not very high in
+comparison of many other in the Moon, nor yet very steep. The Vale it self
+ABCD, is much of the figure of a Pear, and from several appearances of it,
+seems to be some very fruitful place, that is, to have its surface all
+covered over with some kinds of vegetable substances; for in all positions
+of the light on it, it seems to give a much fainter reflection then the
+more barren tops of the incompassing Hills, and those a much fainter then
+divers other cragged, chalky, or rocky Mountains of the Moon. So that I am
+not unapt to think, that the Vale may have Vegetables _analogus_ to our
+Grass, Shrubs, and Trees; and most of these incompassing Hills may be
+covered with so thin a vegetable Coat, as we may observe the Hills with us
+to be, such as the short Sheep pasture which covers the Hills of
+_Salisbury_ Plains.
+
+Up and down in several parts of this place here describ'd (as there are
+multitudes in other places all over the surface of the Moon) may be
+perceived several kinds of pits, which are shap'd almost like a dish, some
+bigger, some less, some shallower, some deeper, that is, they seem to be a
+hollow _Hemisphere_, incompassed with a round rising bank, as if the
+substance in the middle had been digg'd up, and thrown on either side.
+These seem to me to have been the effects of some motions within the body
+of the Moon, _analogus_ to our Earthquakes, by the eruption of which, as it
+has thrown up a brim, or ridge, round about, higher then the Ambient
+surface of the Moon, so has it left a hole, or depression, in the middle,
+proportionably lower; divers places resembling some of these, I have
+observ'd here in _England_, on the tops of some Hills, which might have
+been caus'd by some Earthquake in the younger dayes of the world. But that
+which does most incline me to this belief, is, first, the generality and
+diversity of the Magnitude of these pits all over the body of the Moon.
+Next, the two experimental wayes, by which I have made a representation of
+them.
+
+The first was with a very soft and well temper'd mixture of Tobacco-pipe
+clay and Water, into which, if I let fall any heavy body, as a Bullet, it
+would throw up the mixture round the place, which for a while would make a
+representation, not unlike these of the Moon; but considering the state and
+condition of the Moon, there seems not any probability to imagine, that it
+should proceed from any cause _analogus_ to this; for it would be difficult
+to imagine whence those bodies should come; and next, how the substance of
+the Moon should be so soft; but if a Bubble be blown under the surface of
+it, and suffer'd to rise, and break; or if a Bullet, or other body, sunk in
+it, be pull'd out from it, these departing bodies leave an impression on
+the surface of the mixture, exactly like these of the Moon, save that these
+also quickly subside and vanish. But the second, and most notable,
+representation was, what I observ'd in a pot of boyling Alabaster, for
+there that powder being by the eruption of vapours reduc'd to a kind of
+fluid consistence, if, whil'st it boyls, it be gently remov'd besides the
+fire, the Alabaster presently ceasing to boyl, the whole surface,
+especially that where some of the last Bubbles have risen, will appear all
+over covered with small pits, exactly shap'd like these of the Moon, and by
+holding a lighted Candle in a large dark Room, in divers positions to this
+surface, you may exactly represent all the _Phaenomena_ of these pits in
+the Moon, according as they are more or less inlightned by the Sun.
+
+And that there may have been in the Moon some such motion as this, which
+may have made these pits, will seem the more probable, if we suppose it
+like our Earth, for the Earthquakes here with us seem to proceed from some
+such cause, as the boyling of the pot of Alabaster, there seeming to be
+generated in the Earth from some subterraneous fires, or heat, great
+quantities of vapours, that is, of expanded aerial substances, which not
+presently finding a passage through the ambient parts of the Earth, do, as
+they are increased by the supplying and generating principles, and thereby
+(having not sufficient room to expand themselves) extreamly condens'd, at
+last overpower, with their _elastick_ properties, the resistence of the
+incompassing Earth, and lifting it up, or cleaving it, and so shattering of
+the parts of the Earth above it, do at length, where they find the parts of
+the Earth above them more loose, make their way upwards, and carrying a
+great part of the Earth before them, not only raise a small brim round
+about the place, out of which they break, but for the most part
+considerable high Hills and Mountains, and when they break from under the
+Sea, divers times, mountainous Islands; this seems confirm'd by the
+_Vulcans_ in several places of the Earth, the mouths of which, for the most
+part, are incompassed with a Hill of a considerable height, and the tops of
+those Hills, or Mountains, are usually shap'd very much like these pits, or
+dishes, of the Moon: Instances of this we have in the descriptions of
+_AEtna_ in _Sicily_, of _Hecla_ in _Iceland_, of _Tenerif_ in the
+_Canaries_, of the several _Vulcans_ in _New-Spain_, describ'd by _Gage_,
+and more especially in the eruption of late years in one of the _Canary_
+Islands. In all of which there is not only a considerable high Hill raised
+about the mouth of the _Vulcan_, but, like the spots of the Moon, the top
+of those Hills are like a dish, or bason. And indeed, if one attentively
+consider the nature of the thing, one may find sufficient reason to judge,
+that it cannot be otherwise; for these eruptions, whether of fire, or
+smoak, alwayes raysing great quantities of Earth before them, must
+necessarily, by the fall of those parts on either side, raise very
+considerable heaps.
+
+Now, both from the figures of them, and from several other circumstances;
+these pits in the Moon seem to have been generated much after the same
+manner that the holes in Alabaster, and the _Vulcans_ of the Earth are
+made. For first, it is not improbable, but that the substance of the Moon
+may be very much like that of our Earth, that is, may consist of an earthy,
+sandy, or rocky substance, in several of its superficial parts, which parts
+being agitated, undermin'd, or heav'd up, by eruptions of vapours, may
+naturally be thrown into the same kind of figured holes, as the small dust,
+or powder of Alabaster. Next, it is not improbable, but that there may be
+generated, within the body of the Moon, divers such kind of internal fires
+and heats, as may produce such Exhalations; for since we can plainly enough
+discover with a _Telescope_, that there are multitudes of such kind of
+eruptions in the body of the Sun it self, which is accounted the most noble
+AEtherial body, certainly we need not be much scandaliz'd at such kind of
+alterations, or corruptions, in the body of this lower and less
+considerable part of the universe, the Moon, which is only secundary, or
+attendant, on the bigger, and more considerable body of the Earth. Thirdly,
+'tis not unlikely, but that supposing such a sandy or mouldring substance
+to be there found, and supposing also a possibility of the generation of
+the internal _elastical_ body (whether you will call it air or vapours)
+'tis not unlikely, I say, but that there is in the Moon a principle of
+gravitation, such as in the Earth. And to make this probable, I think, we
+need no better Argument, then the roundness, or globular Figure of the body
+of the Moon it self, which we may perceive very plainly by the _Telescope_,
+to be (bating the small inequality of the Hills and Vales in it, which are
+all of them likewise shap'd, or levelled, as it were, to answer to the
+center of the Moons body) perfectly of a Sphaerical figure, that is, all
+the parts of it are so rang'd (bating the comparitively small ruggedness of
+the Hills and Dales) that the outmost bounds of them are equally distant
+from the Center of the Moon, and consequently, it is exceedingly probable
+also, that they are equidistant from the Center of gravitation; and indeed,
+the figure of the superficial parts of the Moon are so exactly shap'd,
+according as they should be, supposing it had a gravitating principle as
+the Earth has, that even the figure of those parts themselves is of
+sufficient efficacy to make the gravitation, and the other two suppositions
+probable: so that the other suppositions may be rather prov'd by this
+considerable Circumstance, or Observation, then this suppos'd Explication
+can by them; for he that shall attentively observe with an excellent
+_Telescope_, how all the Circumstances, notable in the shape of the
+superficial parts, are, as it were, exactly adapted to suit with such a
+principle, will, if he well considers the usual method of Nature in its
+other proceedings, find abundant argument to believe it to have really
+there also such a principle; for I could never observe, among all the
+mountainous or prominent parts of the Moon (whereof there is a huge
+variety) that any one part of it was plac'd in such a manner, that if there
+should be a gravitating, or attracting principle in the body of the Moon,
+it would make that part to fall, or be mov'd out of its visible posture.
+Next, the shape and position of the parts is such, that they all seem put
+into those very shapes they are in by a gravitating power: For first, there
+are but very few clifts, or very steep declivities in the ascent of these
+Mountains; for besides those Mountains, which are by _Hevelius_ call'd the
+_Apennine_ Mountains, and some other, which seem to border on the Seas of
+the Moon, and those only upon one side, as is common also in those Hills
+that are here on the Earth; there are very few that seem to have very steep
+ascents, but, for the most part, they are made very round, and much
+resemble the make of the Hills and Mountains also of the Earth; this may be
+partly perceived by the Hills incompassing this Vale, which I have here
+describ'd; and as on the Earth also, the middlemost of these Hills seems
+the highest, so is it obvious also, through a good _Telescope_, in those of
+the Moon; the Vales also in many are much shap'd like those of the Earth,
+and I am apt to think, that could we look upon the Earth from the Moon,
+with a good _Telescope_, we might easily enough perceive its surface to be
+very much like that of the Moon.
+
+Now whereas in this small draught, (as there would be multitudes if the
+whole Moon were drawn after this manner) there are several little
+Ebullitions, or Dishes, even in the Vales themselves, and in the
+incompassing Hills also; this will, from this supposition, (which I have, I
+think, upon very good reason taken) be exceeding easily explicable; for, as
+I have several times also observ'd, in the surface of Alabaster so ordered,
+as I before describ'd, so may the later eruptions of vapours be even in the
+middle, or on the edges of the former; and other succeeding these also in
+time may be in the middle or edges of these, &c. of which there are
+Instances enough in divers parts of the body of the Moon, and by a boyling
+pot of Alabaster will be sufficiently exemplifi'd.
+
+To conclude therefore, it being very probable, that the Moon has a
+principle of gravitation, it affords an excellent distinguishing Instance
+in the search after the cause of gravitation, or attraction, to hint, that
+it does not depend upon the diurnal or turbinated motion of the Earth, as
+some have somewhat inconsiderately supposed and affirmed it to do; for if
+the Moon has an attractive principle, whereby it is not only shap'd round,
+but does firmly contain and hold all its parts united, though many of them
+seem as loose as the sand on the Earth, and that the Moon is not mov'd
+about its Center; then certainly the turbination cannot be the cause of the
+attraction of the Earth, and therefore some other principle must be thought
+of, that will agree with all the secundary as well as primary Planets. But
+this, I confess, is but a probability, and not a demonstration, which (from
+any Observation yet made) it seems hardly capable of, though how successful
+future indeavours (promoted by the meliorating of Glasses, and observing
+particular circumstances) may be in this, or any other, kind, must be with
+patience expected.
+
+       *       *       *       *       *
+
+
+_FINIS._
+
+       *       *       *       *       *
+
+
+THE TABLE.
+
+Observat. 1. Of the point of a Needle.
+
+_A Description of it: what other Bodies have the sharpest points: of the
+ruggedness of polisht Metal. A description of a printed point. Of very
+small writing, and the use of it for secret intelligence: the cause of the
+coursness of printed lines and points._
+
+Observ. 2. Of the Edge of a Razor.
+
+_A description of it: the causes of its roughness: of the roughness of very
+well polisht Optick Glasses._.
+
+Obser. 3. Of fine Lawn.
+
+_A description of it: A silken Flax mention'd, an attempt to explicate the
+_Phaenomena_ of it, with a conjecture at the cause of the gloss of Silk._
+
+Observ. 4. Of Tabby.
+
+_A short description of it. A conjecture about the reason why Silk is so
+susceptible of vivid colours: and why Flax and Hair is not. A conjecture,
+that it way perhaps be possible to spin a kind of artificial Silk, out of
+some glutinous substance that may equalize natural Silk._
+
+Observ. 5. Of water'd Silks.
+
+_The great unaccurateness of artificial works. A description of a piece of
+water'd Silk; an Explication of the cause of the _Phaenomena_: the way by
+which that operation is perform'd: some other _Phaenomena_ mention'd
+depending on the same cause._
+
+Observ. 6. Of Glass-Canes.
+
+_The exceeding smallness of some of these Bodies. By what means the
+hollowness of these small pipes was discover'd: several _Phaenomena_ of it
+mention'd. An attempt to explicate them from the congruity and incongruity
+of Bodies: what those proprieties are. A hypothetical explication of
+fluidity: of the fluidity of the air, and several other _Phaenomena_ of it:
+of congruity & incongruity; illustrated with several Experiments: what
+effects may be ascrib'd to these properties: an explication of the
+roundness of the surface of fluid Bodies: how the ingress of fluid bodies
+into a small hole of an heterogenious body is hindred by incongruity; a
+multitude of _Phaenomena_ explicable hereby. Several Quaeries propounded;
+1. Concerning the propagation of light through differing mediums. 2.
+Concerning Gravity. 3. Concerning the roundness of the Sun, Moon, and
+Planets. 4. Concerning the roundness of Fruits, Stones, and divers
+artificial Bodies. His Highness Prince _Rupert's_ way of making Shot. Of
+the roundness of Hail. Of the grain of _Kettering_ Stone, and of the Sparks
+of fire. 5. Concerning springiness and tenacity. 6. Concerning the original
+of Fountains; several Histories and Experiments relating thereto. 7.
+Concerning the dissolution of Bodies in Liquors. 8. Concerning the
+universality of this Principle: what method was taken in making and
+applying experiments. The explication of filtration, and several other
+_Phaenomena_; such as the motion of Bodies on the surface of Liquors;
+several Experiments mention'd to this purpose. Of the height to which the
+water may rise in these Pipes; and a conjecture about the juices of
+Vegetables, & the use of their pores. A further explication of Congruity:
+And an attempt of solving the _Phaenomena_ of the strange Experiment of the
+suspension of the _Mercury_ at a much greater height then thirty inches.
+The efficacy of immediate contact, and the reason of it._
+
+Observ. 7. Of Glass drops.
+
+_Several Experiments made with these small Bodies. The manner of the
+breaking and flawing of them, explicated by Figures. What other bodies will
+be flawed much in the same manner: so other tryals, and a description of
+the Drops themselves: some conjectures at the cause of the _Phaenomena_,
+indeavoured to be made probable by several Arguments and Experiments. An
+Experiment of the expansion of Water by heat, and shrinking by cold: the
+like Proprieties suppos'd in Glass drops, and what effects proceed from
+them: the seven Propositions on which the conjectures are grounded.
+Experiments to shew, that bodies expand by heat. The manner of making
+_Thermometers_, and the Instrument for _graduating_ them. The manner of
+_graduating_ them, and their use: Other Experiments to prove the expansion
+of bodies by heat. Four experimental Arguments to prove the expansion of
+Glass by heat: further prov'd by the Experiment of boyling Alabaster; which
+is explicated. An explication of the contracting of heated Glass upon
+cooling. An explication how the parts of the Glass become bent by sudden
+cold, and how kept from extricating themselves by the contignation of the
+Glass drop; which is further explicated by another Experiment made with a
+hollow Glass ball: the reason of the flying asunder of the parts further
+explicated: that 'tis probable these bodies may have many flaws, though not
+visible, and why: how a gradual heating and cooling does put the parts of
+Glass, and other hardned bodies, into a looser texture._
+
+Observ. 8. Of Fiery Sparks.
+
+_The occasion and manner of making this Experiment: divers Observations set
+down in order to the finding out the reasons: some conjectures concerning
+it, which are endeavoured to be explicated and confirm'd by several
+Experiments and Reasons: the _Hypothesis_ a little further explicated. Some
+Observations about the Globular Figure: and an Experiment of reducing the
+filings of Tin or Lead to exactly round Globules._
+
+Observ. 9. Of Fantastical Colours.
+
+_The texture of _Muscovy_ Glass; its Figures: what other Bodies are like
+it: that it exhibits several colours, and how: several Observations and
+Experiments about those colours: the reason why on this occasion the nature
+of colours is inquir'd into. A conjecture at the reason of these colours
+explicated by several Experiments and Reasons: First, by continual cleaving
+the Body till it become colour'd. Secondly, by producing all kinds of
+colours with two flat Plates of Glass. Thirdly, by blowing Glass so thin in
+the Lamp, till it produce the same effect. Fourthly, by doing the same with
+Bubbles of divers other transparent Bodies: the reasons of the colours on
+nealed Steel, where by the way the causes of the hardning and tempering of
+Steel, endeavour'd to be shewn and explicated by several Reasons and
+Experiments: the reason of the colours on Lead, Brass, Copper, Silver, &c.
+other Instances of such colour'd bodies in animal substances: several other
+distinguishing Observations. _Des Cartes Hypothesis_ of Colours examin'd.
+An _Hypothesis_ for the explication of light by motion, indeavoured to be
+explicated and determined by several Reasons and Experiments: three
+distinguishing Properties of the motion of light. The distinguishing
+Properties of a trasparent _Medium_ [that there seems to be no Experiment
+that proves the Instantaneous motion of light] the manner of the
+propagation of light through them. Of the _homogeniety_ and _heterogeniety_
+of transparent _Mediums_, and what effects they cause on the Rayes of
+light, explicated by a Figure: an Examination of the refraction of the Rays
+by a plain Surface, which causes Colours. An Examination of the like
+effects produced by a spherical Surface: the use that may be made of these
+Experiments, for the examination of several _Hypotheses_ of Colours. _Des
+Cartes Hypothesis_ examin'd. Some Difficulties taken notice of in it. What
+seems most likely to be the cause of colour: that propriety is indeavoured
+to be shewn in a Glass ball: that the reflection is not necessary to
+produce Colours nor a double refraction: the _Hypothesis_ further examined,
+both in the _pellucid Medium_ and in the Eye. The definitions of Colours;
+and a further explication and examination of the Proprieties of _laminated_
+Bodies; by what means they conduce to the production of Colours._
+
+Observ. 10. Of Metalline Colours.
+
+_That all Colours seem to be caus'd by refraction. An _Hypothesis_
+consonant hereunto, explicated by Figures. How several Experiments, of the
+sudden changing of Colours by Chymical Liquors may be hereby explicated:
+how many wayes such Chymical Liquors may alter the colours of Bodies.
+Objections made against this _Hypothesis_ of two colours only, indeavoured
+to be answer'd, by several Reasons and Experiments. The reason why some
+Colours are capable of being diluted, others not: what those are: that
+probably the particles of most metalline Colours are transparent; for this
+several Arguments and Observations are recited: how Colours become
+incapable of diluting, explicated by a Similitude. An Instrument, by which
+one and the same coloured Liquor at once exhibited all the degrees of
+colours between the palest yellow and deepest red: as likewise another that
+exhibited all varieties of blues: several Experiments try'd with these
+Boxes. An Objection drawn from the nature of Painters colours answered:
+that diluting and whitening a colour are different operations; as are
+deepening and blackening: why some may be diluted by grinding, and some
+other by being tempered with Oyl: several Experiments for the explicating
+of some former Assertions: why Painters are forced to make use of many
+colours: what those colours are: and how mixt. The conclusion, that most
+coloured Bodies seem to consist of transparent particles: that all colours
+dissoluble in Liquors are capable of diluting: some of mixing, what a
+strange variety may thereby be produc'd._
+
+Observ. 11. Of the Figures of Sand.
+
+_Of the substances and shapes of common and other Sands: a description of a
+very small Shell._
+
+Observ. 12. Of Gravel in Urine.
+
+_A description of such Gravel, and some tryals made with it, and
+conjectures at its cause._
+
+Obser. 13. Of Diamonds in Flints.
+
+_A description and examination of some of them, explicated further by
+Cornish Diamonds: several Observations about reflection and refraction:
+and some deductions therefrom; as an explication of whiteness; that the Air
+has a stronger reflection then Water. How several Bodies may be made
+transparent: an explication of the _Phaenomena_ of _Oculus Mundi_. Of the
+regular Geometrical Figures of several Bodies: an hypothetical explication
+mentioned: the method of prosecuting this inquiry._
+
+Observ. 14. Of frozen Figure.
+
+_The Figures of hoar Frost, and the Vortices on windows: several
+Observations on the branched Figures of Urine: the Figures of _Regulus
+Martis stellatus_, and of Fern. Of the Figures of Snow. Of frozen water._
+
+Observ. 15. Of Kettering Stone.
+
+_A description of the Figure of the Particles, and of the Pores, and of the
+Contexture. Several Observations and Considerations thereupon: some
+Conjectures about the _medium_ and propagation of light, and the
+constitution of fluid and transparent Bodies. Several Experiments to prove
+the porousness of Marble, and some other Stones. An account of some
+Experiments to this purpose made on an _Oculus Mundi_: some other
+Considerations and Experiments about the porousness of Bodies: some other
+Considerations about the propagation of light and refraction._
+
+Observ. 16. Of Charcoal.
+
+_Of two sort of Pores to be found in all Woods and Vegetables; the shape of
+them; the number, thickness, manner and use of these Pores. An explication
+of the _Phaenomena_ of Coals. The manner of charring Wood, or any other
+body. What part of Wood is combustible. An _Hypothesis_ of fire explicated
+in twelve particulars, wherein the Action of the Air, as a _Menstruum_ in
+the dissolution of all sulphureous bodies, is very particularly explicated,
+and some other Considerations about the Air proposed: the examination of a
+piece of _Lignum fossile_ sent from _Rome_, and some Conclusions thence
+deduc'd._
+
+Observ. 17. Of Wood, and other Bodies, petrified.
+
+_Several Observations of divers kinds of these substances. A more
+particular examination and explication of one very notable piece of
+petrified Wood; and some Conjectures about the cause of those productions:
+several Observations made on other petrified Bodies, as shells, &c. And
+some probable Conclusions thence deduc'd, about the original cause of those
+Bodies._
+
+Observ. 18. Of the Pores of Cork, and other Bodies.
+
+_Several Observations and Considerations about the nature of Cork: the
+number of Pores in a cubical Inch, and several considerations about Pores.
+Several Experiments and Observations about the nature of Cork: the Texture
+and Pores of the Pith of an Elder, and several other Trees: of the Stales
+of Burdocks, Teasels, Daisies, Carret, Fennel, Ferne, Reeds, &c. of the
+frothy texture of the Pith of a Feather: some Conjectures about the
+probability of values in these Pores. Argued also from the _Phaenomena_ of
+sensible and humble Plant: some Observations on which are inserted._
+
+Observ. 19. Of a Vegetable growing on blighted Leaves.
+
+_Several Observations and Examinations made of them: several Considerations
+about spontaneous generation arising from the putrefaction of Bodies._
+
+Observ. 20. Of Blew Mould and Mushromes.
+
+_The description of several kinds of Moulds. The method of proceeding in
+natural Inquiries. Several Considerations about the nature of Mould and
+Mushromes. 1. That they may be produc'd without seed. 2. That they seem to
+have none. 3. That Salts, &c. are shap'd into as curious figures without a
+seed. 4. Of a kind of Mushrome growing in a Candle: A more particular
+explication of this last sort of Mushromes. 5. Of the figure and manner of
+the production of petrified Iceicles: several deductions from these
+Considerations, about the nature of the vegetation of Mould and Mushromes._
+
+Observ. 21. Of Moss.
+
+_The description of several sorts of Mosses; upon this occasion several
+Conjectures, about the manner of the production of these kinds of Bodies,
+are hinted, and some of them explicated by a Similitude taken from a piece
+of Clock-work, The vast difference of the bigness of vegetable Bodies; and
+the probability that the least may comprehend as curious contrivances as
+the greatest. Of multitudes of other Moulds, Mosses, and Mushromes, and
+other vegetating Principles, in Water, Wood, _&c.
+
+Observ. 22. Of Sponges, and other fibrous Bodies.
+
+_Several Observations and Conjectures about the making of these Bodies, and
+several Histories out of Authors. Scarce any other Body hath such a
+texture; the fibrous texture of Leather, Spunk, &c. (which are there
+describ'd) come nearest to it That upon tryal with a piece of Spunge and
+Oyl the necessity of respiration could not be alter'd._
+
+Observ. 23. Of the Form of Seaweed.
+
+_From the curiously shap'd Surface of this Sea-weed, and some others, is
+conjectured the possibility of Multitudes of the like._
+
+Observ. 24. Of the Surfaces of some Leaves.
+
+_The description, 1. Of the bald Surfaces of Leaves. 2. Of the downy
+Surfaces of several others. 3. Of the gummous exsudation, or small
+transparent Pearls, discovered with a _Microscope_ in several others. An
+Instance of all which is afforded in a Rosemary Leaf._
+
+Observ. 25. Of the stinging Points of a Nettle.
+
+_A description of the Needles and several other contrivances in the leaf of
+a Nettle: how the stinging pain is created: upon this several
+considerations about poysoning Darts are set down. An Experiment of killing
+Effs, and Fishes with Salt. Some conjectures at the efficacy of Baths; the
+use that may be made of injecting into the Veins. A very remarkable History
+out of _Bellonius_; and some Considerations about staining and dying of
+Bodies._
+
+Observ. 26. Of Cowage.
+
+_The definition of it out of _Parkinson_: an Experiment made of it: a
+description, and some conjectures at the cause of the _Phaenomena_._
+
+Observ. 27. Of the Beard of a wild Oat.
+
+_The description of its shape and properties: the manner of making a
+_Hygroscope_ with it; and a Conjecture at the causes of these motions, and
+of the motions of the Muscles._
+
+Observ. 28. Of the Seeds of _Venice_ Looking-glass.
+
+_The description of them._
+
+Obser. 29. Of the Seeds of Time.
+
+_A description of them. A digression about Natures method._
+
+Observ. 30. Of Poppy Seeds.
+
+_The description and use of them._
+
+Observ. 31. Of Purslane Seeds.
+
+_A description of these and many other Seeds._
+
+Observ. 32. Of Hair.
+
+_The description of several sorts of Hair; their Figures and Textures: the
+reason of their colours, A description of the texture of the skin, and of
+Spunk and Sponges: by what passages and pores of the skin transpiration
+seems to be made. Experiments to prove the porousness of the skin of
+Vegetables._
+
+Observ. 33. Of the Scales of a Soale.
+
+_A description of their beauteous form._
+
+Observ. 34. Of the Sting of a Bee.
+
+_A description of its shape, mechanisme, and use._
+
+Observ. 35. Of Feathers.
+
+_A description of the shape and curious contexture of Feathers: and some
+conjectures thereupon._
+
+Obser. 36. Of Peacocks Feathers.
+
+_A description of their curious form and proprieties; with a conjecture at
+the cause of their variable colours._
+
+Obser. 37. Of the Feet of Flyes, and other Insects.
+
+_A description of their figure, parts, and use; and some considerations
+thereupon._
+
+Obser. 38. Of the Wings of Flyes.
+
+_After what manner and how swiftly the wings of Insects move. A description
+of the Pendulums under the wings, and their motion; the shape and structure
+of the parts of the wing._
+
+Obser. 39. Of the Head of a Fly.
+
+_1. All the face of a Drone-fly is nothing almost but eyes. 2. Those are of
+two magnitudes. 3. They are Hemispheres, and very reflective and smooth. 4.
+Some directed towards every quarter. 5. How the fly cleanses them. 6. Their
+number. 7. Their order: divers particulars observ'd in the dissecting a
+head. That these are very probably the eyes of the Creature; argued from
+several Observations and Experiments, that Crabs, Lobsters, Shrimps, seem
+to be water Insects, and to be framed much like Air Insects. Several
+Considerations about their manner of vision._
+
+Obser. 40. Of the Teeth of a Snail.
+
+_A brief description of it._
+
+Observ. 41. Of the Eggs of Silkworms.
+
+_Several Observables about the Eggs of Insects._
+
+Observ. 42. Of a blue Fly.
+
+_A description of its outward and inward parts. Its hardiness to indure
+freezing, and sleeping in Spirit of wine._
+
+Observ. 43. Of a water Insect.
+
+_A description of its shape, transparency, motion, both internal and
+progressive, and transformation. A History somewhat _Analogus_ cited out of
+_Piso_. Several Observations about the various wayes of the generations of
+Insects: by what means they act so seemingly wisely and prudently. Several
+Quaeries propounded. Postscript, containing a relation of another very odd
+way of the generation of Insects. An Observation about the fertility of the
+Earth of our Climate in producing Insects, and of divers other wayes of
+their generation._
+
+Observ. 44. Of the tufted Gnat.
+
+_Several Observables about Insects, and a more particular description the
+parts of this Gnat._
+
+Ob. 45. Of the great belly'd Gnat.
+
+_A short description of it._
+
+Obser. 46. Of a white Moth.
+
+_A description of the feathers and wings of this, and several other
+Insects. Divers Considerations about the wings, and the flying of Insects
+and Birds._
+
+Obs. 47. Of the Shepherd Spider.
+
+_A description of its Eyes: and the sockets of its long legs: and a
+Conjecture of the mechanical reason of its fabrick; together with a
+supposition, that 'tis not unlikely, but Spiders may have the make of their
+inward parts exactly like a Crab, which may be call'd a water Spider._
+
+Obser. 48. Of the hunting Spider.
+
+_A short description of it; to which is annext an excellent History of it,
+made by Mr. _Evelyn_. Some further Observations on other Spiders, and their
+Webs, together with an examination of a white Substance flying up and down
+in the Air after a Fog._
+
+Obser. 49. Of an Ant.
+
+_That all small Bodies, both Vegetable and Animal, do quickly dry and
+wither. The best remedy I found to hinder it, and to make the Animal lye
+still to be observ'd. Several particulars related of the actions of this
+Creature and a short description of its parts._
+
+Obs. 50. Of the wandring Mite.
+
+_A description of this Creature, and of another very small one, which
+usually bore it company. A Conjecture at the original of Mites._
+
+Observ. 51. Of a Crab-like Insect.
+
+_A brief description of it._
+
+Observ. 52. Of a Book-worm.
+
+_A description of it; where by the way is inserted a digression,
+experimentally explicating the _Phaenomena_ of Pearl. A consideration of
+its digestive faculty._
+
+Observ. 53. Of a Flea.
+
+_A short description of it._
+
+Observ. 54. Of a Louse.
+
+_A description of its parts, and some notable circumstances._
+
+Observ. 55. Of Mites.
+
+_The exceeding smalness of some Mites, and their Eggs. A description of the
+Mites of Cheese: and an intimation of the variety of forms in other Mites,
+with a Conjecture at the reason._
+
+Ob. 56. Of small Vine-Mites.
+
+_A description of them; a ghess at their original; their exceeding smalness
+compar'd with that of a Wood-louse, from which they may be suppos'd to
+come._
+
+Observ. 57. Of Vinegar-worms.
+
+_A description of them, with some considerations on their motions._
+
+Obs. 58. Of the Inflexion of the Rays of Light in the Air.
+
+_A short rehearsal of several _Phaenomena_. An attempt to explicate them:
+the supposition founded on two Propositions, both which are indeavoured to
+be made out by several Experiments, What density and rarity is in respect
+of refraction: the refraction of Spirit of Wine compared with that of
+common Water: the refraction of Ice. An Experiment of making an Undulation
+of the Rays by the mixing of Liquors of differing density. The explication
+of _inflection_, mechanically and hypothetically: what Bodies have such an
+inflection. Several Experiments to shew that the Air has this propriety;
+that it proceeds from the differing density of the Air: that the upper and
+under part of the Air are of differing density: some Experiments to prove
+this. A Table of the strength of the spring of the Air, answering to each
+degree of extension; when first made, and when repeated. Another Experiment
+of compressing the Air. A Table of the strength of the Air, answering to
+each compression and expansion; from which the height of the Air may be
+suppos'd indefinite; to what degree the Air is rarifi'd at any distance
+above the Surface of the Earth: how, from this, Inflection is inferr'd; and
+several _Phaenomena_ explain'd. That the Air near the Earth is compos'd of
+parts of differing density; made probable by several Experiments and
+Observations; how this propriety produces the effects of the waving and
+dancing of Bodies; and of the twinkling of the Stars. Several _Phaenomena_
+explicated. Some Quaeries added._
+
+1. _Whether this Principle may not be made use of, for perfecting Optick
+Glasses? What might be hoped from it if it were to be done?_
+
+2. _Whether from this Principle the apparition of some new Stars may not be
+explicated?_
+
+3. _Whether the height of the Air may be defin'd by it?_
+
+4. _Whether there may not sometimes be so great a disparity of density
+between the upper and under parts of the Air, as to make a reflecting
+Surface?_
+
+5. _Whether, if so, this will not explicate the _Phaenomena_ of the Clouds.
+An Experiment to this purpose?_
+
+7. _Whether the Rayes from the top of Mountains are not bended into
+Curve-lines by inflection? An Argument for it, taken from an Experiment
+made on St. _Paul_'s Steeple._
+
+8. _Whether the distance of the Planets will not be more difficult to be
+found? What wayes are most likely to rectifie the distance of the Moon: the
+way of fitting _Telescopes_ for such Observations. How to make the
+Observations, and how from them to find the true distance of the Moon at
+any time. How the distance of the Sun may be found by two Observators. The
+way by the Dicotomy of the Moon uncertain. That the distance of the Moon
+may be less then it has been hitherto suppos'd. _Kepler_'s Supposition not
+so probable: the explication of the _Phaenomena_ by another _Hypothesis_._
+
+Observ. 59. Of the fixt Stars.
+
+_Of the multitudes of Stars discoverable by the _Telescope_, and the
+variety of their magnitudes: 78. Stars distinguisht in the _Pleiades_: that
+there are degrees of bigness even in the Stars accounted of the same
+magnitude: the longer the Glasses are, and the bigger apertures they will
+indure, the more fit they are for these discoveries: that 'tis probable,
+longer Glasses would yet make greater discoveries. 5. Stars discover'd in
+the _Galaxie_ of _Orion_'s Sword._
+
+Observ. 60. Of the Moon.
+
+_A description of a Vale in the Moon; what call'd by _Hevelius_ and
+_Ricciolus_, and how describ'd by them: with what substances the hills of
+the Moon may be cover'd. A description of the pits of the Moon, and a
+conjecture at their cause: two Experiments that make it probable, that of
+the surface of boyl'd Alabaster dust seeming the most likely to be
+resembled by eruptions of vapours out of the body of the Moon: that
+Earthquakes seem to be generated much the same way, and their effects seem
+very similar. An Argument that there may be such variations in the Moon,
+because greater have been observ'd in the Sun: because substance of the
+Moon and Earth seem much alike: and because 'tis probable the Moon has a
+gravitating principle: this is argued from several particulars. The reason
+why several pits are one within another. The use that may be made of this
+Instance of a gravity in the Moon._
+
+       *       *       *       *       *
+
+
+[1] _Schem._ 2. _Fig._ 1.
+
+[2] Diop. ch. 10. Sec 9.
+
+[3] _Schem._ 2. _Fig._ 2.
+
+[4] _Schem._ 1.* _Fig._ 3.
+
+[5] _Schem._ 3. _Fig._ 1.
+
+[6] _Schem._ 3. _Fig._ 2.
+
+[7] _Schem._ 4.
+
+[8] _Schem._ 4. _Fig._ 1.
+
+[9] _Schem._ 6. _Fig._ 3.
+
+[10] _Schem._ 6. _Fig._ 3.
+
+[11] _Schem._ 8. _Fig._ 1.
+
+[12] _Schem._ 8. _Fig._ 2.
+
+[13] _Schem._ 9. _Fig._ 1.
+
+    [14] See _Schem._ 11. _Fig._ 2.
+
+[15] _Fig._ 1. _Schem._ 36.
+
+[16] _Fig._ 3.
+
+
+
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+The Project Gutenberg eBook, Micrographia, by Robert Hooke
+
+
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at www.gutenberg.org
+
+
+
+
+
+Title: Micrographia
+       Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries Thereupon
+
+
+Author: Robert Hooke
+
+Release Date: March 29, 2005  [eBook #15491]
+
+Language: English
+
+Character set encoding: ISO-8859-1
+
+
+***START OF THE PROJECT GUTENBERG EBOOK MICROGRAPHIA***
+
+
+E-text prepared by Robert Shimmin, Keith Edkins, and the Project Gutenberg
+Online Distributed Proofreading Team
+
+
+
+Note: Project Gutenberg also has an HTML version of this
+      file which includes the original remarkable illustrations.
+      See 15491-h.htm or 15491-h.zip:
+      (https://www.gutenberg.org/dirs/1/5/4/9/15491/15491-h/15491-h.htm)
+      or
+      (https://www.gutenberg.org/dirs/1/5/4/9/15491/15491-h.zip)
+
+      The reader of this text file should understand that words or
+      phrases between underscores should be imagined to be set in italics.
+
+
+
+
+
+       *       *       *       *       *
+
+By the Council of the ROYAL SOCIETY of London
+for Improving of Natural Knowledge.
+
+Ordered, That the Book written by Robert Hooke, M.A. Fellow of this
+Society, Entituled, Micrographia, or some Physiological Descriptions of
+Minute Bodies, made by Magnifying Glasses, with Observations and Inquiries
+thereupon, Be printed by John Martyn, and James Allestry, Printers to
+the said Society.
+
+Novem. 23. 1664.
+
+BROUNCKER. P.R.S.
+
+       *       *       *       *       *
+
+
+MICROGRAPHIA:
+
+OR SOME
+
+Physiological Descriptions
+
+OF
+
+MINUTE BODIES
+
+MADE BY
+
+MAGNIFYING GLASSES
+
+WITH
+
+OBSERVATIONS and INQUIRIES thereupon.
+
+       *       *       *       *       *
+
+By R. HOOKE, Fellow of the ROYAL SOCIETY.
+
+       *       *       *       *       *
+
+
+
+
+
+
+  _Non possis oculo quantum contendere Linceus,
+  Non tamen idcirco contemnas Lippus inungi._ Horat. Ep. lib. 1.
+
+
+
+[Illustration]
+
+       *       *       *       *       *
+
+
+LONDON, Printed by Jo. Martyn, and Ja. Allestry, Printers to the
+ROYAL SOCIETY, and are to be sold at their Shop at the Bell in S.
+Paul's Church-yard. M DC LX V.
+
+       *       *       *       *       *
+
+
+TO THE
+
+KING.
+
+SIR,
+
+I Do here most humbly lay this _small_ Present at _Your Majesties_ Royal
+feet. And though it comes accompany'd with two _disadvantages_, the
+_meanness_ of the _Author_, and of the _Subject_; yet in both I am
+_incouraged_ by the _greatness_ of your _Mercy_ and your _Knowledge_. By
+the _one_ I am taught, that you can _forgive_ the most _presumptuous
+Offendors_: And by the _other_, that you will not _esteem_ the least work
+of _Nature_, or _Art_, unworthy your _Observation_. Amidst the many
+_felicities_ that have accompani'd _your Majesties_ happy _Restauration_
+and _Government_, it is none of the least considerable that _Philosophy_
+and _Experimental Learning_ have _prosper'd_ under your _Royal Patronage_.
+And as the calm prosperity of your Reign has given us the _leisure_ to
+follow these _Studies_ of _quiet_ and _retirement_, so it is just, that the
+_Fruits_ of them should, by way of _acknowledgement_, be return'd to _your
+Majesty_. There are, Sir, several other of your Subjects, of your _Royal
+Society_, now busie about _Nobler_ matters: The _Improvement_ of
+_Manufactures_ and _Agriculture_, the _Increase_ of _Commerce_, the
+_Advantage_ of _Navigation_: In all which they are _assisted_ by _your
+Majesties Incouragement_ and _Example_. Amidst all those _greater_ Designs,
+I here presume to bring in that which is more _proportionable_ to the
+_smalness_ of my Abilities, and to offer some of the _least_ of all
+_visible things_, to that _Mighty King_, that has _establisht an Empire_
+over the best of all _Invisible things_ of this World, the _Minds_ of Men.
+
+Your Majesties most humble
+and most obedient
+Subject and Servant,
+
+ROBERT HOOKE.
+
+       *       *       *       *       *
+
+TO THE
+
+ROYAL SOCIETY.
+
+After my _Address_ to our _Great Founder_ and _Patron_, I could not but
+think my self oblig'd, in consideration of those _many Ingagements_ you
+have laid upon me, to offer these my _poor Labours_ to this MOST
+ILLUSTRIOUS ASSEMBLY. YOU have been pleas'd formerly to accept of these
+rude _Draughts_. I have since added to them some _Descriptions_, and some
+_Conjectures_ of my own. And therefore, together with YOUR _Acceptance_, I
+must also beg YOUR _pardon_. The Rules YOU have prescrib'd YOUR selves in
+YOUR Philosophical Progress do seem the best that have ever yet been
+practis'd. And particularly that of avoiding _Dogmatizing_, and the
+_espousal_ of any _Hypothesis_ not sufficiently grounded and confirm'd by
+_Experiments_. This way seems the most excellent, and may preserve both
+_Philosophy_ and _Natural History_ from its former _Corruptions_. In saying
+which, I may seem to condemn my own Course in this Treatise; in which there
+may perhaps be some _Expressions_, which may seem more _positive_ then YOUR
+Prescriptions will permit: And though I desire to have them understood only
+as _Conjectures_ and _Quæries_ (which YOUR Method does not altogether
+disallow) yet if even in those I have exceeded, 'tis fit that I should
+declare, that it was not done by YOUR Directions. For it is most
+unreasonable, that YOU should undergo the _imputation_ of the _faults_ of
+my _Conjectures_, seeing YOU can receive so _small advantage_ of reputation
+by the _sleight Observations_ of
+
+YOUR most humble and
+most faithful Servant
+
+ROBERT HOOKE.
+
+       *       *       *       *       *
+
+
+THE
+
+PREFACE.
+
+It is the great prerogative of Mankind above other Creatures, that we are
+not only able to _behold_ the works of Nature, or barely to _sustein_ our
+lives by them, but we have also the power of _considering_, _comparing_,
+_altering_, _assisting_, and _improving_ them to various uses. And as this
+is the peculiar priviledge of humane Nature in general, so is it capable of
+being so far advanced by the helps of Art, and Experience, as to make some
+Men excel others in their Observations, and Deductions, almost as much as
+they do Beasts. By the addition of such _artificial Instruments_ and
+_methods_, there may be, in some manner, a reparation made for the
+mischiefs, and imperfection, mankind has drawn upon it self, by negligence,
+and intemperance, and a wilful and superstitious deserting the Prescripts
+and Rules of Nature, whereby every man, both from a deriv'd corruption,
+innate and born with him, and from his breeding and converse with men, is
+very subject to slip into all sorts of errors.
+
+The only way which now remains for us to recover some degree of those
+former perfections, seems to be, by rectifying the operations of the
+_Sense_, the _Memory_, and _Reason_, since upon the evidence, the
+_strength_, the _integrity_, and the _right correspondence_ of all these,
+all the light, by which our actions are to be guided is to be renewed, and
+all our command over things it to be establisht.
+
+It is therefore most worthy of our consideration, to recollect their
+several defects, that so we may the better understand how to supply them,
+and by what assistances we may _inlarge_ their power, and _secure_ them in
+performing their particular duties.
+
+As for the actions of our _Senses_, we cannot but observe them to be in
+many particulars much outdone by those of other Creatures, and when at
+best, to be far short of the perfection they seem capable of: And these
+infirmities of the Senses arise from a double cause, either from the
+_disproportion of the Object to the Organ_, whereby an infinite number of
+things can never enter into them, or else from _error in the Perception_,
+that many things, which come within their reach, are not received in a
+right manner.
+
+The like frailties are to be found in the _Memory;_ we often let many
+things _slip away_ from us, which deserve to be retain'd, and of those
+which we treasure up, a great part is either _frivolous_ or _false_; and if
+good, and substantial, either in tract of time _obliterated_, or at best so
+_overwhelmed_ and buried under more frothy notions, that when there is need
+of them, they are in vain sought for.
+
+The two main foundations being so deceivable, it is no wonder, that all
+the succeeding works which we build upon them, of arguing, concluding,
+defining, judging, and all the other degrees of Reason, are lyable to the
+same imperfection, being, at best, either vain, or uncertain: So that the
+errors of the _understanding_ are answerable to the two other, being
+defective both in the quantity and goodness of its knowledge; for the
+limits, to which our thoughts are confin'd, are small in respect of the
+vast extent of Nature it self; some parts of it are _too large_ to be
+comprehended, and some _too little_ to be perceived. And from thence it
+must follow, that not having a full sensation of the Object, we must be
+very lame and imperfect in our conceptions about it, and in all the
+proportions which we build upon it; hence, we often take the _shadow_ of
+things for the _substance_, small _appearances_ for good _similitudes_,
+_similitudes_ for _definitions;_ and even many of those, which we think, to
+be the most solid definitions, are rather expressions of our own misguided
+apprehensions then of the true nature of the things themselves.
+
+The effects of these imperfections are manifested in different ways,
+according to the temper and disposition of the several minds of men, some
+they incline to _gross ignorance_ and stupidity, and others to a
+_presumptuous imposing_ on other mens Opinions, and a _confident
+dogmatizing_ on matters, whereof there it no assurance to be given.
+
+Thus all the uncertainty, and mistakes of humane actions, proceed either
+from the narrowness and wandring of our _Senses_, from the slipperiness or
+delusion of our _Memory_, from the confinement or rashness of our
+_Understanding_, so that 'tis no wonder, that our power over natural causes
+and effects is so slowly improv'd, seeing we are not only to contend with
+the obscurity and _difficulty of the things_ whereon we work and think, but
+even the _forces of our own minds_ conspire to betray us.
+
+These being the dangers in the process of humane Reason, the remedies of
+them all can only proceed from the _real_, the _mechanical_, the
+_experimental_ Philosophy, which has this advantage over the Philosophy of
+_discourse_ and _disputation_, that whereas that chiefly aims at the
+subtilty of its Deductions and Conclusions, without much regard to the
+first ground-work, which ought to be well laid on the Sense and Memory; so
+this intends the right ordering of them all, and the making them
+serviceable to each other.
+
+The first thing to be undertaken in this weighty work, is a _watchfulness
+over the failings_ and an _inlargement of the dominion_, of the Senses.
+
+To which end it is requisite, first, That there should be a _scrupulous_
+choice, and a _strict examination_, of the reality, constancy, and
+certainty of the Particulars that we admit: This is the first rise whereon
+truth is to begin, and here the most severe, and most impartial diligence,
+must be imployed; the storing up of all, without any regard to evidence or
+use, will only tend to darkness and confusion. We must not therefore esteem
+the riches of our Philosophical treasure by the _number_ only, but chiefly
+by the _weight_; the most _vulgar_ Instances are not to be neglected, but
+above all, the most _instructive_ are to be entertain'd; the footsteps of
+Nature are to be trac'd, not only in her _ordinary course_, but when she
+seems to be put to her shifts, to make many _doublings_ and _turnings_, and
+to use some kind of art in indeavouring to avoid our discovery.
+
+The next care to be taken, in respect of the Senses, is a supplying of
+their infirmities with _Instruments_, and, as it were, the adding of
+_artificial Organs_ to the _natural_; this in one of them has been of late
+years accomplisht with prodigious benefit to all sorts of useful knowledge,
+by the invention of Optical Glasses. By the means of _Telescopes_, there is
+nothing so _far distant_ but may be represented to our view; and by the
+help of _Microscopes_, there is nothing so _small_, as to escape our
+inquiry; hence there is a new visible World discovered to the
+understanding. By this means the Heavens are open'd, and a vast number of
+new Stars, and new Motions, and new Productions appear in them, to which
+all the ancient Astronomers were utterly Strangers. By this the Earth it
+self, which lyes so neer us, under our feet, shews quite a new thing to us,
+and in every _little particle_ of its matter; we now behold almost as great
+a variety of Creatures, as we were able before to reckon up in the whole
+_Universe_ it self.
+
+It seems not improbable, but that by these helps the subtilty of the
+composition of Bodies, the structure of their parts, the various texture of
+their matter, the instruments and manner of their inward motions, and all
+the other possible appearances of things, may come to be more fully
+discovered; all which the ancient _Peripateticks_ were content to
+comprehend in two general and (unless further explain'd) useless words of
+_Matter_ and _Form_. From whence there may arise many admirable advantages,
+towards the increase of the _Operative_, and the _Mechanick_ Knowledge, to
+which this Age seems so much inclined, because we may perhaps be inabled to
+discern all the secret workings of Nature, almost in the same manner as we
+do those that are the productions of Art, and are manag'd by Wheels, and
+Engines, and Springs, that were devised by humane Wit.
+
+In this kind I here present to the World my imperfect Indeavours; which
+though they shall prove no other way considerable, yet, I hope, they may be
+in some measure useful to the main Design of a _reformation_ in Philosophy,
+if it be only by shewing, that there it not so much requir'd towards it,
+any strength of _Imagination_, or exactness of _Method_, or depth of
+_Contemplation_ (though the addition of these, where they can be had, must
+needs produce a much more perfect composure) as a sincere _Hand_, and a
+_faithful_ Eye, to examine, and to record, the things themselves as they
+appear.
+
+And I beg my Reader, to let me take the boldness to assure him, that in
+this present condition of knowledge, a man so qualified, as I have
+indeavoured to be, only with resolution, and integrity, and plain
+intentions of imploying his _Senses_ aright, may venture to compare the
+reality and the usefulness of his services, towards the true Philosophy,
+with those of other men, that are of much stronger, and more acute
+_speculations_, that shall not make use of the same method by the Senses.
+
+The truth is, the Science of Nature has been already too long made only a
+work of the _Brain_ and the _Fancy_: It is now high time that it should
+return to the plainness and soundness of _Observations_ on _material_ and
+_obvious_ things. It is said of great Empires, That _the best way to
+preserve them from decay, is to bring them back to the first Principles,
+and Arts, on which they did begin_. The same is undoubtedly true in
+Philosophy, that by wandring far away into _invisible Notions_, has almost
+quite destroy'd it self, and it can never be recovered, or continued, but
+by returning into the same _sensible paths_, in which it did at first
+proceed.
+
+If therefore the Reader expects from me any infallible Deductions, or
+certainty of _Axioms_, I am to say for my self, that those stronger Works
+of Wit and Imagination are above my weak Abilities; or if they had not been
+so, I would not have made use of them in this present Subject before me:
+Whenever he finds that I have ventur'd at any small Conjectures, at the
+causes of the things that I have observed, I beseech him to look, upon them
+only as _doubtful Problems_, and _uncertain ghesses_, and not as
+unquestionable Conclusions, or matters of unconfutable Science; I have
+produced nothing here, with intent to bind his understanding to an
+_implicit_ consent; I am so far from that, that I desire him, not
+absolutely to rely upon these Observations of my eyes, if he finds them
+contradicted by the future Ocular Experiments of other and impartial
+Discoverers.
+
+As for my part, I have obtained my end, if these my small Labours shall be
+thought fit to take up some place in the large stock, of _natural
+Observations_, which so many hands are busie in providing. If I have
+contributed the _meanest foundations_ whereon others may raise nobler
+_Superstructures_, I am abundantly satisfied; and all my ambition is, that
+I may serve to the great Philosophers of this Age, as the makers and the
+grinders of my Glasses did to me; that I may prepare and furnish them with
+some _Materials_, which they may afterwards _order_ and _manage_ with
+better skill, and to far greater advantage.
+
+The next remedies in this universal cure of the Mind are to be applyed to
+the _Memory_, and they are to consist of such Directions as may inform us,
+what things are best to be _stor'd up_ for our purpose, and which is the
+best way of so _disposing_ them, that they may not only be _kept in
+safety_, but ready and convenient, to be at any time _produc'd_ for use, as
+occasion shall require. But I will not here prevent my self in what I may
+say in another Discourse, wherein I shall make an attempt to propose some
+Considerations of the manner of compiling a Natural and Artificial History,
+and of so ranging and registring its Particulars into Philosophical Tables,
+as may make them most useful for the raising of _Axioms_ and _Theories_.
+
+The last indeed is the most _hazardous_ Enterprize, and yet the most
+_necessary_; and that is, to take such care that the _Judgment_ and the
+_Reason_ of Man (which is the third Faculty to be repair'd and improv'd)
+should receive such assistance, as to avoid the dangers to which it it by
+nature most subject. The Imperfections, which I have already mention'd, to
+which it is lyable, do either belong to the _extent_, or the _goodness_ of
+its knowledge; and here the difficulty is the greater, least that which may
+be thought a _remedy_ for the one should prove _destructive_ to the other,
+least by seeking to inlarge our Knowledge, we should render it weak, and
+uncertain; and least by being too scrupulous and exact about every
+Circumstance of it, we should confine and streighten it too much.
+
+In both these the middle wayes are to be taken, nothing it to be_
+omitted_, and yet every thing to pass a _mature deliberation_: No
+_Intelligence_ from Men of all Professions, and quarters of the World, to
+be _slighted_, and yet all to be so _severely examin'd_, that there remain
+no room for doubt or instability; much _rigour_ in admitting, much
+_strictness_ in comparing, and above all, much _slowness_ in debating, and
+_shyness_ in determining, is to be practised. The _Understanding_ is to
+_order_ all the inferiour services of the lower Faculties; but yet it is to
+do this only as a _lawful Master_, and not at a _Tyrant._ It must not
+_incroach_ upon their Offices, nor take upon it self the employments which
+belong to either of them. It must _watch_ the irregularities of the Senses,
+but it must not go before them, or _prevent_ their information. It must
+_examine_, _range_, and _dispose_ of the bank which it laid up in the
+Memory: but it must be sure to make _distinction_ between the _sober_ and
+_well collected heap_, and the _extravagant Ideas_, and _mistaken Images_,
+which there it may sometimes light upon. So many are the _links_, upon
+which the true Philosophy depends, of which, if any one be _loose_, or
+_weak_, the whole _chain_ is in danger of being dissolv'd; it is to _begin_
+with the Hands and Eyes, and to _proceed_ on through the Memory, to be
+_continued_ by the Reason; nor is it to stop there, but to _come about_ to
+the Hands and Eyes again, and so, by a _continual passage round_ from one
+Faculty to another, it is to be maintained in life and strength, as much as
+the body of man it by the _circulation_ of the blood through the several
+parts of the body, the Arms, the Feet, the Lungs, the Heart, and the Head.
+
+If once this method were followed with diligence and attention, there is
+nothing that lyes within the power of human Wit (or which is far more
+effectual) of human Industry, which we might not compass; we might not only
+hope for Inventions to equalize those of _Copernicus_, _Galileo_,
+_Gilbert_, _Harvy_, and of others, whose Names are almost lost, that were
+the Inventors of _Gun-powder_, the _Seamans Compass_, _Printing_,
+_Etching_, _Graving_, _Microscopes_, &c. but multitudes that may far exceed
+them: for even those discoveries seem to have been the products of some
+such method, though but imperfect; What may not be therefore expected from
+it if thoroughly prosecuted? _Talking_ and _contention of Arguments_ would
+soon be turn'd into _labours_; all the fine _dreams_ of Opinions, and
+_universal metaphysical natures_, which the luxury of subtil Brains has
+devis'd, would quickly vanish, and give place to _solid Histories_,
+_Experiments_ and _Works._ And as at first, mankind _fell_ by _tasting_ of
+the forbidden Tree of Knowledge, so we, their Posterity, may be in part
+_restor'd_ by the same way, not only by _beholding_ and _contemplating_,
+but by _tasting_ too those fruits of Natural knowledge, that were never yet
+forbidden.
+
+From hence the World may be assisted with _variety_ of Inventions, _new_
+matter for Sciences may be _collected_, the _old improv'd_, and their
+_rust_ rubb'd away; and as it is by the benefit of Senses that we receive
+all our Skill in the works of Nature, so they also may be wonderfully
+benefited by it, and may be guided to an easier and more exact performance
+of their Offices; 'tis not unlikely, but that we may find out wherein our
+Senses are deficient, and as easily find wayes of repairing them.
+
+The Indeavours of Skilful men have been most conversant about the
+assistance of the Eye, and many noble Productions have followed upon it;
+and from hence we may conclude, that there it a way open'd for advancing
+the operations, not only of all the other Senses, but even of the Eye it
+self; that which has been already done ought not to content us, but rather
+to incourage us to proceed further, and to attempt greater things in the
+same, and different wayes.
+
+'Tis not unlikely, but that there may be yet invented several other helps
+for the eye, at much exceeding those already found, as those do the bare
+eye, such as by which we may perhaps be able to discover _living Creatures_
+in the Moon, or other Planets, the _figures_ of the compounding Particles
+of matter, and the particular _Schematisms_ and _Textures_ of Bodies.
+
+And as _Glasses_ have highly promoted our _seeing_, so 'tis not
+improbable, but that there may be found many _Mechanical Inventions_ to
+improve our other Senses, of _hearing_, _smelling_, _tasting_, _touching._
+'Tis not impossible to hear a _whisper_ a _furlongs_ distance, it having
+been already done; and perhaps the nature of the thing would not make it
+more impossible, though that furlong should be ten times multiply'd. And
+though some famous Authors have affirm'd it impossible to hear through the
+_thinnest plate_ of _Muscovy-glass_; yet I know a way, by which 'tis easie
+enough to hear one speak through a _wall a yard thick_. It has not been yet
+thoroughly examin'd, how far _Otocousticons_ may be improv'd, nor what
+other wayes there may be of _quickning_ our hearing, or _conveying_ sound
+through _other bodies_ then the _Air_: for that that it not the only
+_medium_, I can assure the Reader, that I have, by the help of a _distended
+wire_, propagated the sound to a very considerable distance in an
+_instant_, or with as seemingly quick a motion as that of light, at least,
+incomparably swifter then that, which at the same time was propagated
+through the Air; and this not only in a straight line, or direct, but in
+one bended in many angles.
+
+Nor are the other three so perfect, but that _diligence_, _attention_, and
+many _mechanical contrivances_, may also highly improve them. For since the
+sense of _smelling_ seems to be made by the _swift passage_ of the _Air_
+(_impregnated_ with the steams and _effluvia_ of several odorous Bodies)
+through the grisly _meanders_ of the Nose whose surfaces are _cover'd_ with
+a very sensible _nerve_, and _moistned_ by a _transudation_ from the
+_processus mamillares_ of the Brain, and some adjoyning _glandules_, and by
+the moist _steam_ of the _Lungs_, with a Liquor convenient for the
+reception of those _effluvia_ and by the adhesion and mixing of those
+steams with that liquor, and thereby affecting the nerve, or perhaps by
+insinuating themselves into the juices of the brain, after the same manner,
+as I have in the following Observations intimated, the parts of Salt to
+pass through the skins of Effs, and Frogs. Since, I say, smelling seems to
+be made by some such way, 'tis not improbable, but that some contrivance,
+for making a great quantity of Air pass quick through the Nose, might at
+much promote the sense of smelling, as the any wayes hindring that passage
+does dull and destroy it. Several tryals I have made, both of hindring and
+promoting this sense, and have succeeded in some according to expectation;
+and indeed to me it seems capable of being improv'd, for the judging of the
+constitutions of many Bodies. Perhaps we may thereby also judge (as other
+Creatures seem to do) what is wholsome, what poyson; and in a word, what
+are the specifick properties of Bodies.
+
+There may be also some other mechanical wayes found out, of sensibly
+perceiving the _effluvia_ of Bodies; several Instances of which, were it
+here proper, I could give of Mineral steams and exhalations; and it seems
+not impossible, but that by some such wayes improved, may be discovered,
+what Minerals lye buried under the Earth, without the trouble to dig for
+them; some things to confirm this Conjecture may be found in _Agricola_,
+and other Writers of Minerals, speaking of the Vegetables that are apt to
+thrive, or pine, in those steams.
+
+Whether also those steams, which seem to issue out of the Earth, and mix
+with the Air (and so to precipitate some _aqueous_ Exhalations, wherewith
+'tis impregnated) may not be by some way detected before they produce the
+effect, seems hard to determine; yet something of this kind I am able to
+discover, by an Instrument I contriv'd to shew all the minute variations in
+the pressure of the Air; by which I constantly find, that before, and
+during the time of rainy weather, the pressure of the Air is less, and in
+_dry weather_, but especially when an _Eastern Wind_ (which having past
+over vast tracts of Land is heavy with Earthy Particles) blows, it is much
+more, though these changes are varied according to very odd Laws.
+
+    The Instrument is this. I prepare a pretty capaceous Bolt-head AB, with
+    a small stem about two foot and a half long DC; upon the end of this D
+    I put on a small bended Glass, or brazen _syphon_ DEF (open at D, E and
+    F, but to be closed with cement at F and E, as occasion serves) whose
+    stem F should be about six or eight inches long, but the bore of it not
+    above half an inch diameter, and very even; these I fix very strongly
+    together by the help of very hard Cement, and then fit the whole Glass
+    ABCDEF into a long Board, or Frame, in such manner, that almost half
+    the head AB may lye buried in a concave Hemisphere cut into the Board
+    RS; then I place it so on the Board RS, as is exprest in the first
+    figure of the first Scheme; and fix it very firm and steady in that
+    posture, so as that the weight of the _Mercury_ that is afterwards to
+    be put into it, may not in the least shake or stir it; then drawing a
+    line XY on the Frame RT, so that it may divide the ball into two equal
+    parts, or that it may pass, as 'twere, through the center of the ball.
+    I begin from that, and divide all the rest of the Board towards UT into
+    inches, and the inches between the 25 and the end E (which need not be
+    above two or three and thirty inches distant from the line XY) I
+    subdivide into Decimals; then stopping the end F with soft Cement, or
+    soft Wax, I invert the Frame, placing the head downwards, and the
+    Orifice E upwards; and by it, with a small Funnel, I fill the whole
+    Glass with Quicksilver; then by stopping the small Orifice E with my
+    finger, I oftentimes erect and invert the whole Glass and Frame, and
+    thereby free the Quicksilver and Glass from all the bubbles or parcels
+    of lurking Air; then inverting it as before, I fill it top full with
+    clear and well strain'd Quicksilver, and having made ready a small ball
+    of pretty hard Cement, by heat made very soft, I press it into the hole
+    E, and thereby stop it very fast; and to secure this Cement from flying
+    out afterward, I bind over it a piece of Leather, that is spread over
+    in the inside with Cement, and wound about it while the Cement is hot:
+    Having thus softned it, I gently erect again the Glass after this
+    manner: I first let the Frame down edge-wayes, till the edge RV touch
+    the Floor, or ly horizontal; and then in that edging posture raise the
+    end RS; this I do, that if there chance to be any Air hidden in the
+    small Pipe E, it may ascend into the Pipe F, and not into the Pipe DC:
+    Having thus erected it, and hung it by the hole Q, or fixt it
+    perpendicularly by any other means, I open the end F, and by a small
+    _Syphon_ I draw out the _Mercury_ so long, till I find the surface of
+    it AB in the head to touch exactly the line XY; at which time I
+    immediately take away the _Syphon_, and if by chance it be run somewhat
+    below the line XY, by pouring in gently a little _Mercury_ at F, I
+    raise it again to its desired height, by this contrivance I make all
+    the sensible rising and falling of the _Mercury_ to be visible in the
+    surface of the _Mercury_ in the Pipe F, and scarce any in the head AB.
+    But because there really is some small change of the upper surface
+    also, I find by several Observations how much it rises in the Ball, and
+    falls in the Pipe F, to make the distance between the two surfaces an
+    inch greater then it was before; and the measure that it falls in the
+    Pipe is the length of the inch by which I am to mark the parts of the
+    Tube F, or the Board on which it lyes, into inches and Decimals: Having
+    thus justned and divided it, I have a large Wheel MNOP, whose outmost
+    limb is divided into two hundred equal parts; this by certain small
+    Pillars is fixt on the Frame RT, in the manner exprest in the Figure.
+    In the middle of this, on the back side, in a convenient frame, is
+    placed a small Cylinder, whose circumference is equal to twice the
+    length of one of those divisions, which I find answer to an inch of
+    ascent, or descent, of _Mercury_: This Cylinder I, is movable on a very
+    small Needle, on the end of which is fixt a very light Index KL, all
+    which are so pois'd on the Axis, or Needle, that no part is heavier
+    then another: Then about this Cylinder is wound a small Clew of Silk,
+    with two small steel Bullets at each end of it GH; one of these, which
+    is somewhat the heavier, ought to be so big, as freely to move to and
+    fro in the Pipe F; by means of which contrivance, every the least
+    variation of the height of the _Mercury_ will be made exceeding visible
+    by the motion to and fro of the small Index KL.
+
+But this is but one way of discovering the _effluvia_ of the Earth mixt
+with the Air; there may be, perhaps many others, witness the _Hygroscope_,
+an Instrument whereby the watery steams volatile in the Air are discerned,
+which the Nose it self is not able to find. This I have describ'd in the
+following Tract in the Description of the Beard of a wild Oat. Others
+there, are, may be discovered both by the Nose, and by other wayes also.
+Thus the _smoak_ of burning _Wood_ is _smelt_, _seen_, and sufficiently
+_felt_ by the eyes: The _fumes_ of burning _Brimstone_ are _smelt_ and
+discovered also by the destroying the Colours of Bodies, as by the
+_whitening of a red Rose_: And who knows, but that the Industry of man,
+following this method, may find out wayes of improving this sense to as
+great a degree of perfection at it is in any Animal, and perhaps yet
+higher.
+
+'Tis not improbable also, but that our _taste_ may be very much improv'd
+either by _preparing_ our taste for the Body, as, after eating _bitter_
+things, _Wine_, or other _Vinous liquors_, are more sensibly tasted; or
+else by _preparing_ Bodies for our tast; as the dissolving of Metals with
+acid Liquors, make them tastable, which were before altogether insipid;
+thus _Lead_ becomes _sweeter_ then Sugar, and _Silver_ more _bitter_ then
+Gall, _Copper_ and _Iron_ of most _loathsome_ tasts. And indeed the
+business of this sense being to discover the presence of dissolved Bodies
+in Liquors put on the Tongue, or in general to discover that a fluid body
+has some solid body dissolv'd in it, and what they are; whatever
+contrivance makes this discovery improves this sense. In this kind the
+mixtures of Chymical Liquors afford many Instances; as the sweet Vinegar
+that is impregnated with Lead may be discovered to be so by the affusion of
+a little of an _Alcalizate solution_: The bitter liquor of _Aqua fortis_
+and _Silver_ may be discover'd to be charg'd with that Metal, by laying in
+it some plates of Copper: 'Tis not improbable also, but there may be
+multitudes of other wayes of discovering the parts dissolv'd, or dissoluble
+in liquors; and what is this discovery but a kind of _secundary tasting_.
+
+'Tis not improbable also, but that the sense of _feeling_ may be highly
+improv'd, for that being a sense that judges of the more _gross_ and
+_robust motions_ of the _Particles_ of _Bodies_, seems capable of being
+improv'd and assisted very many wayes. Thus for the distinguishing of
+_Heat_ and _Cold_, the _Weather-glass_ and _Thermometer_, which I have
+describ'd in this following Treatise, do exceedingly perfect it; by each of
+which the least variations of heat or cold, which the most Acute sense is
+not able to distinguish, are manifested. This is oftentimes further
+promoted also by the help of _Burning-glasses_, and the like, which collect
+and unite the radiating heat. Thus the _roughness_ and _smoothness_ of a
+Body is made much more sensible by the help of a _Microscope_, then by the
+most _tender_ and _delicate Hand_. Perhaps, a Physitian might, by several
+other _tangible_ proprieties, discover the constitution of a Body as well
+as by the _Pulse_. I do but instance in these, to shew what possibility
+there may be of many others, and what probability and hopes there were of
+finding them, if this method were followed; for the Offices of the five
+Senses being to detect either the _subtil_ and _curious Motions_ propagated
+through all _pellucid_ or perfectly _homogeneous_ Bodies; Or the more
+_gross_ and _vibrative Pulse_ communicated through the _Air_ and all other
+convenient _mediums_, whether fluid or solid: Or the _effluvia_ of Bodies
+_dissolv'd_ in the _Air_; Or the _particles_ of bodies _dissolv'd_ or
+_dissoluble_ in _Liquors_, or the more _quick_ and _violent shaking motion_
+of _heat_ in all or any of these: whatsoever does any wayes promote any of
+these kinds of _criteria_, does afford a way of improving some one sense.
+And what a multitude of these would a diligent Man meet with in his
+inquiries? And this for the helping and promoting the _sensitive faculty_
+only.
+
+Next, as for the _Memory_, or _retentive faculty_, we may be sufficiently
+instructed from the _written Histories_ of _civil actions_, what great
+assistance may be afforded the Memory, in the committing to writing things
+observable in _natural operations_. If a Physitian be therefore accounted
+the more able in his Faculty, because he has had long experience and
+practice, the remembrance of which, though perhaps very imperfect, does
+regulate all his after actions: What ought to be thought of that man, that
+has not only a perfect _register_ of his own experience, but it grown _old_
+with the experience of many hundreds of years, and many thousands of men.
+
+And though of late, men, beginning to be sensible of this convenience,
+have here and there registred and printed some few _Centuries_, yet for the
+most part they are set down very lamely and imperfectly, and, I fear, many
+times not so truly, they seeming, several of them, to be design'd more for
+_Ostentation_ then _publique use_: For, not to instance, that they do, for
+the most part, omit those Experiences they have made, wherein their
+Patients have miscarried, it is very easie to be perceiv'd, that they do
+all along _hyperbolically extol_ their own Prescriptions, and vilifie those
+of others. Notwithstanding all which, these kinds of Histories are
+generally esteem'd useful, even to the ablest Physitian.
+
+What may not be expected from the _rational_ or _deductive Faculty_ that
+is furnisht with such _Materials_, and those so readily _adapted_, and
+rang'd for use, that in a moment, at 'twere, thousands of Instances,
+serving for the _illustration_, _determination_, or _invention_, of almost
+any inquiry, may be _represented_ even to the sight? How neer the nature of
+_Axioms_ must all those _Propositions_ be which are examin'd before so many
+_Witnesses_? And how difficult will it be for any, though never so subtil
+an error in Philosophy, to _scape_ from being discover'd, after it has
+indur'd the _touch_, and so many other _tryals_?
+
+What kind of mechanical way, and physical invention also is there requir'd
+that might not this may be found out? The _Invention_ of a way to find the
+_Longitude_ of places is easily perform'd, and that to as great
+_perfection_ as is desir'd, or to at great an _accurateness_ as the
+_Latitude_ of places can be found at Sea; and perhaps yet also to a greater
+certainty then that has been hitherto found, as I shall very speedily
+freely manifest to the world. The way of _flying_ in the Air seems
+principally unpracticable, by reason of the _want of strength_ in _humane
+muscles_; if therefore that could be suppli'd, it were, I think, easie to
+make twenty contrivances to perform the office of _Wings_: What Attempts
+also I have made for the supplying that Defect, and my successes therein,
+which, I think, are wholly new, and not inconsiderable, I shall in another
+place relate.
+
+'Tis not unlikely also, but that _Chymists_, if they followed this method,
+might find out their so much sought for _Alkahest_. What an _universal
+Menstruum_, which dissolves all sorts of _Sulphureous Bodies_, I have
+discover'd (which hat not been before taken notice of as such) I have shewn
+in the sixteenth Observation.
+
+What a prodigious variety of Inventions in _Anatomy_ has this latter Age
+afforded, even in our own Bodies in the very _Heart_, by which we live, and
+the Brain, which is the seat of our knowledge of other things? witness all
+the excellent Works of _Pecquet_, _Bartholinus_, _Billius_, and many
+others; and at home, of Doctor _Harvy_, Doctor _Ent_, Doctor _Willis_,
+Doctor _Glisson_. In _Celestial Observations_ we have far exceeded all the
+Antients, even the _Chaldeans_ and _Egyptians_ themselves, whose _vast
+Plains_, _high Towers_, and _clear Air_, did not give them so great
+advantages over us, as have over them by our _Glasses_. By the help of
+which, they have been very much outdone by the famous _Galileo_,
+_Hevelius_, _Zulichem_; and our own Countrymen, Mr. _Rook_, Doctor _Wren_,
+and the great Ornament of our Church and Nation, the _Lord Bishop of
+Exeter_. And to say no more in _Aerial Discoveries_, there has been a
+wonderful progress made by the _Noble Engine_ of _the most Illustrious Mr.
+Boyle_, whom it becomes me to mention with all honour, not only as my
+particular Patron, but as the _Patron_ of _Philosophy_ it self; which he
+every day _increases_ by his _Labours_, and _adorns_ by his _Example_.
+
+The good success of all these _great Men_, and many others, and the now
+seemingly great _obviousness_ of most of their and divers other Inventions,
+which from the beginning of the world have been, as 'twere, trod on, and
+yet not minded till these last _inquisitive_ Ages (an Argument that there
+may be yet behind multitudes of the like) puts me in mind to recommend such
+Studies, and the prosecution of them by such methods, to the _Gentlemen_ of
+our Nation, whose _leisure_ makes them fit to _undertake_, and the _plenty_
+of their fortunes _to accomplish_, extraordinary things in this way. And I
+do not only propose this kind of _Experimental Philosophy_ as matter of
+high _rapture_ and _delight_ of the mind, but even as a _material_ and
+_sensible Pleasure_. So vast it the _variety of Objects_ which will come
+under their Inflections, so many _different wayes_ there are _of handling_
+them, so great is the _satisfaction_ of _finding_ out _new things_, that I
+dare compare the _contentment_ which they will injoy, not only to that of
+_contemplation_, but even to that which most men prefer of _the very Senses
+themselves_.
+
+And if they will please to take any incouragement from so mean and so
+imperfect endeavours as mine, upon my own experience, I can assure them,
+without arrogance, That there has not been any inquiry or Problem in
+_Mechanicks_, that I have hitherto propounded to my self, but by a certain
+method (which I may on some other opportunity explain) I have been able
+presently to examine the possibility of it; and if so, as easily to
+excogitate divers wayes of performing it: And indeed it is possible to do
+as much by _this method_ in _Mechanicks_, as by _Algebra_ can be perform'd
+in _Geometry_. Nor can I at all doubt, but that the same method is as
+applicable to _Physical Enquiries_, and as likely to find and reap thence
+at plentiful a crop of Inventions; and indeed there seems to be no subject
+so barren, but may with this good husbandry be highly improv'd.
+
+Toward the prosecution of this method in _Physical Inquiries_, I have here
+and there _gleaned_ up an _handful_ of Observations, in the collection of
+most of which I made use of _Microscopes_, and some other _Glasses_ and
+_Instruments_ that improve the sense; which way I have herein taken, not
+that there are not multitudes of useful and pleasant Observables, yet
+uncollected, obvious enough without the helps of Art, but only to promote
+the use of Mechanical helps for the Senses, both in the surveying the
+already visible World, and for the discovery of many others hitherto
+unknown, and to make us, with the great Conqueror, to be affected that we
+have not yet overcome one World when there are so many others to be
+discovered, every considerable improvement of _Telescopes_ or _Microscopes_
+producing new Worlds and _Terra-Incognita's_ to our view.
+
+The Glasses I used were of our English make, but though very good of the
+kind, yet far short of what might be expected, could we once find a way of
+making Glasses Elliptical, or of some more true shape; for though both
+_Microscopes_, and _Telescopes_, as they now are, will magnifie an Object
+about a thousand thousand times bigger then it appears to the naked eye;
+yet the Apertures of the Object-glasses are so very small, that very few
+Rays are admitted, and even of those few there are so many false, that the
+Object appears _dark_ and _indistinct_: And indeed these inconveniences are
+such, as seem inseparable from Spherical Glasses, even when most exactly
+made; but the way we have hitherto made use of for that purpose is so
+imperfect, that there may be perhaps ten wrought before one be made
+tolerably good, and most of those ten perhaps every one differing in
+goodness one from another, which is an Argument, that the way hitherto used
+is, at least, very uncertain. So that these Glasses have a double defect;
+the one, that very few of them are exactly true wrought; the other, that
+even of those that are best among them, none will admit a sufficient number
+of Rayes to magnifie the Object beyond a determinate bigness. Against which
+Inconveniences the only Remedies I have hitherto met with are these.
+
+    First, for _Microscopes_ (where the Object we view is near and within
+    our power) the best way of making it appear bright in the Glass, is to
+    cast a great quantity of light on it by means of _convex glasses_, for
+    thereby, though the aperture be very small, yet there will throng in
+    through it such multitudes, that an Object will by this means indure to
+    be magnifi'd as much again as it would be without it. The way for doing
+    which is this. I make choice of some Room that has only one window open
+    to the South, and at about three or four foot distance from this
+    Window, on a Table, I place my _Microscope_, and then so place either a
+    round Globe of Water, or a very deep clear_ plano convex_ Glass (whose
+    convex side is turn'd towards the Window) that there is a great
+    quantity of Rayes collected and thrown upon the Object: Or if the Sun
+    shine, I place a small piece of oyly Paper very near the Object,
+    between that and the light; then with a good large Burning-Glass I so
+    collect and throw the Rayes on the Paper, that there may be a very
+    great quantity of light pass through it to the Object; yet I so
+    proportion that light, that it may not singe or burn the Paper. Instead
+    of which Paper there may be made use of a small piece of Looking-glass
+    plate, one of whose sides is made rough by being rubb'd on a flat Tool
+    with very find sand, this will, if the heat be leisurely cast on it,
+    indure a much greater degree of heat, and consequently very much
+    augment a convenient light. By all which means the light of the Sun, or
+    of a Window, may be so cast on an Object, as to make it twice as light
+    as it would otherwise be without it, and that without any inconvenience
+    of glaring, which the immediate light of the Sun is very apt to create
+    in most Objects; for by this means the light is so equally diffused,
+    that all parts are alike inlightned; but when the immediate light of
+    the Sun falls on it, the reflexions from some few parts are so vivid,
+    that they drown the appearance of all the other, and are themselves
+    also, by reason of the inequality of light, indistinct, and appear only
+    radiant spots.
+
+    But because the light of the Sun, and also that of a Window, is in a
+    continual variation, and so many Objects cannot be view'd long enough
+    by them to be throughly examin'd; besides that, oftentimes the Weather
+    is so dark and cloudy, that for many dayes together nothing can be
+    view'd: And because also there are many Objects to be met with in the
+    night, which cannot so conveniently be kept perhaps till the day,
+    therefore to procure and cast a sufficient quantity of light on an
+    Object in the night, I thought of, and often used this, Expedient.
+
+    I procur'd me a small Pedestal, such as is describ'd in the fifth
+    Figure of the first _Scheme_ on the small Pillar AB, of which were two
+    movable Armes CD, which by means of the Screws EF, I could fix in any
+    part of the Pillar; on the undermost of these I plac'd a pretty large
+    Globe of Glass G, fill'd with exceeding clear Brine, stopt, inverted,
+    and fixt in the manner visible in the Figure; out of the side of which
+    Arm proceeded another Arm H, with many joynts; to the end of which was
+    fastned a deep plain _Convex glass_ I, which by means of this Arm could
+    be moved too and fro, and fixt in any posture. On the upper Arm was
+    placed a small Lamp K, which could be to mov'd upon the end of the Arm,
+    as to be set in a fit posture to give light through the Ball: By means
+    of this Instrument duly plac'd, as is exprest in the Figure, with the
+    small flame of a Lamp may be cast as great and convenient a light on
+    the Object as it will well indure; and being always constant, and to be
+    had at any time, I found most proper for drawing the representations of
+    those small Objects I had occasion to observe.
+
+    None of all which ways (though much beyond any other hitherto made use
+    of by any I know) do afford a sufficient help, but after a certain
+    degree of magnifying, they leave us again in the lurch. Hence it were
+    very desirable, that some way were thought of for making the
+    Object-glass of such a Figure as would conveniently bear a large
+    Aperture.
+
+As for _Telescopes_, the only improvement they seem capable of, is the
+increasing of their length; for the Object being remote, there is no
+thought of giving it a greater light then it has; and therefore to augment
+the. Aperture, the Glass must be ground of a very large sphere; for, by
+that means, the longer the Glass be, the bigger aperture will it bear, if
+the Glasses be of an equal goodness in their kind. Therefore a six will
+indure a much larger Aperture then a three foot Glass, and a sixty foot
+Glass will proportionably bear a greater Aperture then a thirty, and will
+as much excel it also as a six foot does a three foot, as I have
+experimentally observ'd in one of that length made by Mr. _Richard Reives_
+here at _London_, which will bear an Aperture above three inches over, and
+yet make the Object proportionably big and distinct; whereas there are very
+few thirty foot Glasses that will indure an Aperture of more then two
+inches over. So that for _Telescopes_, supposing we had a very ready way of
+making their Object Glasses of exactly spherical Surfaces, we might, by
+increasing the length of the Glass, magnifie the Object to any assignable
+bigness. And for performing both these, I cannot imagine any way more
+easie, and more exact, then by this following Engine, by means of which,
+any Glasses, of what length soever, may be speedily made. It seems the most
+easie, because with one and the same Tool may be with care ground an Object
+Glass, of any length or breadth requisite, and that with very little or no
+trouble in fitting the Engine, and without much skill in the Grinder. It
+seems to be the most exact, for to the very last stroke the Glass does
+regulate and rectifie the Tool to its exact Figure; and the longer or more
+the Tool and Glass are wrought together, the more exact will both of them
+be of the desir'd Figure. Further, the motions of the Glass and Tool do so
+cross each other, that there is not one point of eithers Surface, but has
+thousands of cross motions thwarting it, so that there can be no kind of
+Rings or Gutters made either in the Tool or Glass.
+
+    The contrivance of the Engine is, only to make the ends of two large
+    _Mandrils_ so to move, that the Centers of them may be at any
+    convenient distance asunder, and that the _Axis_ of the _Mandrils_
+    lying both in the same plain produc'd, may meet each other in any
+    assignable Angle; both which requisites may be very well perform'd by
+    the Engine describ'd in the third Figure of the first _Scheme_: where
+    AB signifies the Beam of a Lath fixt perpendicularly or Horizontally,
+    CD the two Poppet heads, fixt at about two foot distance, EF an Iron
+    _Mandril_, whose tapering neck F runs in an adapted tapering brass
+    Collar; the other end E runs on the point of a Screw G; in a convenient
+    place of this is fastned H a pully Wheel, and into the end of it, that
+    comes through the Poppet head C, is screwed a Ring of a hollow
+    _Cylinder_ K, or some other conveniently shap'd Tool, of what wideness
+    shall be thought most proper for the cize of Glasses, about which it is
+    to be imploy'd: As, for Object glasses, between twelve foot and an
+    hundred foot long, the Ring may be about six inches over, or indeed
+    somewhat more for those longer Glasses. It would be convenient also and
+    not very chargeable, to have four or five several Tools; as one for all
+    Glasses between an inch and a foot, one for all Glasses between a foot
+    and ten foot long, another for all between ten and an hundred, a fourth
+    for all between a hundred and a thousand foot long; and if Curiosity
+    shall ever proceed so far, one for all lengths between a thousand and
+    ten thousand foot long; for indeed the principle is such, that
+    supposing the _Mandrils_ well made, and of a good length, and supposing
+    great care be used in working and polishing them, I see no reason, but
+    that a Glass of a thousand, nay of ten thousand foot long, may be as
+    well made as one of ten; for the reason is the same, supposing the
+    _Mandrils_ and Tools be made sufficiently strong, so that they cannot
+    bend; and supposing the Glass, out of which they are wrought, be
+    capable of so great a regularity in its parts as to refraction: this
+    hollow _Cylinder_ K is to contain the Sand, and by being drove round
+    very quick to and fro by means of a small Wheel, which may be mov'd
+    with ones foot, serves to grind the Glass: The other _Mandril_ is
+    shap'd like this, but it has an even neck instead of a taper one, and
+    runs in a Collar, that by the help of a Screw and a joynt made like M
+    in the Figure, it can be still adjustned to the wearing or wasting
+    neck: into the end of this _Mandril_ is screwed a Chock N on which with
+    Cement or Glew is fastned the piece of Glass Q that is to be form'd;
+    the middle of which Glass is to be plac'd just on the edge of the Ring
+    and the Lath OP is to be set and fixt (by means of certain pieces and
+    screws the manner whereof will be sufficiently evidenc'd by the Figure)
+    in such an Angle as is requisite to the forming of such a Sphere as the
+    Glass is design'd to be of; the geometrical ground of which being
+    sufficiently plain, though not heeded before, I shall, for brevities
+    sake, pass over. This last _Mandril_ to be made (by means of the
+    former, or some other Wheel) to run round very swift also, by which two
+    cross motions the Glass cannot chuse (if care be us'd) but be wrought
+    into a most exactly spherical Surface.
+
+But because we are certain, from the _Laws of refraction_ (which I I have
+experimentally found to be so, by an Instrument I shall presently describe)
+that _the lines of the angles of Incidence are proportionate to the lines
+of the angles of Refraction_, therefore if Glasses could be made of those
+kind of Figures, or some other, such as the most incomparable _Des Cartes_
+has invented, and demonstrated in his Philosophical and Mathematical Works,
+we might hope for a much greater perfection of Opticks then can be
+rationally expected from spherical ones; for though, _cæteris paribus_, we
+find, that the larger the _Telescope_ Object Glasses are, and the shorter
+those of the _Microscope_, the better they magnify, yet both of them,
+beside such determinate dimensions, are by certain inconveniences rendred
+unuseful; for it will be exceeding _difficult_ to make and _manage_ a Tube
+above an _hundred foot long_, and it will be as difficult to _inlighten_ an
+Object less then an hundred part of an inch distant from the Object Glass.
+
+I have not as yet made any attempts of that kind, though I know two or
+three wayes, which, as far as I have yet considered, seem very probable,
+and may invite me to make a tryal as soon as I have an opportunity, of
+which I may hereafter perhaps acquaint the world. In the Interim, I shall
+describe the Instrument I even now mention'd, by which the _refraction_ of
+all kinds of Liquors may be most exactly measur'd, thereby to give the
+curious an opportunity of making what further tryals of that kind they
+shall think requisite to any of their intended tryals; and to let them see
+that the laws of Refraction are not only notional.
+
+    The Instrument consisted of five Rulers, or long pieces placed
+    together, after the manner exprest in the second Figure of the first
+    _Scheme_, where AB denotes a straight piece of wood about six foot and
+    two inches long, about three inches over, and an inch and half thick,
+    on the back side of which was hung a small plummet by a line stretcht
+    from top to bottom, by which this piece was set exactly upright, and so
+    very firmly fixt; in the middle of this was made a hole or center, into
+    which one end of a hollow cylindrical brass Box CC, fashion'd as I
+    shall by and by describe, was plac'd, and could very easily and truly
+    be mov'd to and fro; the other end of this Box being put into, and
+    moving in, a hole made in a small arm DD; into this box was fastned the
+    long Ruler EF, about three foot and three or four inches long, and at
+    three foot from the above mention'd Centers PP was a hole E, cut
+    through, and cross'd with two small threads, and at the end of it was
+    fixt a small sight G, and on the back side of it was fixt a small Arm
+    H, with a Screw to fix it in any place on the Ruler LM; this Ruler LM
+    was mov'd on the Center B (which was exactly three foot distance from
+    the middle Center P) and a line drawn through the middle of it LM, was
+    divided by a Line of cords into some sixty degrees, and each degree was
+    subdivided into minutes, so that putting the cross of the threads in E
+    upon any part of this divided line, I presently knew what Angle the two
+    Rules AB and EF made with each other, and by turning the Screw in H, I
+    could fix them in any position. The other Ruler also RS was made much
+    after the same manner, only it was not fixt to the hollow cylindrical
+    Box, but, by means of two small brass Armes or Ears, it mov'd on the
+    Centers of it; this also, by means of the cross threads in the hole S,
+    and by a Screw in K, could be fastned on any division of another line
+    of cords of the same radius drawn on NO. And so by that means, the
+    Angle made by the two Rulers, AB and RS, was also known. The Brass box
+    CC in the middle was shap'd very much like the Figure X, that is, it
+    was a cylindrical Box stopp'd close at either end, off of which a part
+    both of the sides and bottomes was cut out, so that the Box, when the
+    Pipe and that was joyned to it, would contain the Water when fill'd
+    half full, and would likewise, without running over, indure to be
+    inclin'd to an Angle, equal to that of the greatest refraction of
+    Water, and no more, without running over. The Ruler EF was fixt very
+    fast to the Pipe V, so that the Pipe V directed the length of the Ruler
+    EF, and the Box and Ruler were mov'd on the Pin TT, so as to make any
+    desirable Angle with the Ruler AB. The bottom of this Pipe V was stop'd
+    with a small piece of exactly plain Glass, which was plac'd exactly
+    perpendicular to the Line of direction, or _Axis_ of the Ruler EF. The
+    Pins also TT were drill'd with small holes through the _Axis_, and
+    through those holes was stretcht and fastned a small Wire. There was
+    likewise a small Pipe of Tin loosly put on upon the end of V, and
+    reaching down to the sight G; the use of which was only to keep any
+    false Rayes of light from passing through the bottom of V, and only
+    admitting such to pass as pierced through the sight G: All things being
+    placed together in the manner describ'd in the Figure; that is, the
+    Ruler AB being fixt perpendicular, I fill'd the Box CC with Water, or
+    any other Liquor, whose refraction I intended to try, till the Wire
+    passing through the middle of it were just covered: then I moved and
+    fixt the Ruler FE at any assignable Angle, and placed the flame of a
+    Candle just against the sight G; and looking through the sight I, I
+    moved the Ruler RS to and fro, till I perceived the light passing
+    through G to be covered, as 'twere, or divided by the dark Wire passing
+    through PP: then turning the Screw in K, I fixt it in that posture: And
+    through the hole S, I observed what degree and part of it was cut by
+    the cross threads in S. And this gave me the Angle of Inclination, APS
+    answering to the Angle of Refraction BPE: for the surface of the Liquor
+    in the Box will be alwayes horizontal, and consequently AB will be a
+    perpendicular to it; the Angle therefore APS will measure, or be the
+    Angle of Inclination in the Liquor; next EPB must be the Angle of
+    Refraction, for the Ray that passes through the sight G, passes also
+    perpendicularly through the Glass _Diaphragme_ at F, and consequently
+    also perpendicularly through the lower surface of the Liquor contiguous
+    to the Glass, and therefore suffers no refraction till it meet with the
+    horizontal surface of the Liquor in CC, which is determined by the two
+    Angles.
+
+By means of this Instrument I can with _little trouble_, and a very small
+quantity of any _Liquor_, examine, most accurately, the _refraction_ of it
+not only for one inclination, but for all; and thereby am inabled to make
+very accurate Tables; several of which I have also experimentally made, and
+find, that _Oyl of Turpentine_ has a much greater Refraction then _Spirit
+of Wine_, though it be _lighter_; and that _Spirit of Wine_ has a greater
+Refraction then _Water_, though it be lighter also; but that _salt Water_
+also has a greater Refraction then _fresh_, though it be _heavier_: but
+_Allum water_ has a less refraction then common _Water_, though heavier
+also. So that it seems, as to the _refraction_ made in a Liquor, the
+_specifick gravity_ is of no efficacy. By this I have also found that look
+what _proportion _the _Sine_ of the Angle of _one Inclination_ has to the
+_Sine_ of the Angle of _Refraction_, correspondent to it, the same
+_proportion_ have all the _Sines_ of other Inclinations to the _Sines_ of
+their appropriate Refractions.
+
+    My way for measuring how much a Glass magnifies an Object, plac'd at a
+    convenient distance from my eye, is this. Having rectifi'd the
+    _Microscope_, to see the desir'd Object through it very distinctly, at
+    the same time that I look upon the Object through the Glass with one
+    eye, I look upon other Objects at the same distance with my other bare
+    eye; by which means I am able, by the help of a _Ruler_ divided into
+    inches and small parts, and laid on the _Pedestal_ of the _Microscope_,
+    to cast, as it were, the magnifi'd appearance of the Object upon the
+    Ruler, and thereby exactly to measure the Diameter it appears of
+    through the Glass, which being compar'd with the Diameter it appears of
+    to the naked eye, will easily afford the quantity of its magnifying.
+
+    The _Microscope_, which for the most part I made use of, was shap'd
+    much like that in the sixth Figure of the first _Scheme_, the Tube
+    being for the most part not above six or seven inches long, though, by
+    reason it had four Drawers, it could very much be lengthened, as
+    occasion required; this was contriv'd with three Glasses; a small
+    Object Glass at A, a thinner Eye Glass about B, and a very deep one
+    about C: this I made use of only when I had occasion to see much of an
+    Object at once; the middle Glass conveying a very great company of
+    radiating Pencils, which would go another way, and throwing them upon
+    the deep Eye Glass. But when ever I had occasion to examine the small
+    parts of a Body more accurately, I took out the middle Glass, and only
+    made use of one Eye Glass with the Object Glass, for always the fewer
+    the Refractions are, the more bright and clear the Object appears. And
+    therefore 'tis not to be doubted, but could we make a_ Microscope _to
+    have one only refraction, it would, _cæteris paribus_, far excel any
+    other that had a greater number. And hence it is, that if you take a
+    very clear piece of a broken _Venice_ Glass, and in a Lamp draw it out
+    into very small hairs or threads, then holding the ends of these
+    threads in the flame, till they melt and run into a small round Globul,
+    or drop, which will hang at the end of the thread; and if further you
+    stick several of these upon the end of a stick with a little sealing
+    Wax, so as that the threads stand upwards, and then on a Whetstone
+    first grind off a good part of them, and afterward on a smooth Metal
+    plate, with a little Tripoly, rub them till they come to be very
+    smooth; if one of these be fixt with a little soft Wax against a small
+    needle hole, prick'd through a thin Plate of Brass, Lead, Pewter, or
+    any other Metal, and an Object, plac'd very near, be look'd at through
+    it, it will both magnifie and make some Objects more distinct then any
+    of the great _Microscopes_. But because these, though exceeding easily
+    made, are yet very troublesome to be us'd, because of their smallness,
+    and the nearness of the Object; therefore to prevent both these, and
+    yet have only two Refractions, I provided me a Tube of Brass, shap'd
+    much like that in the fourth Figure of the first _Scheme_; into the
+    smaller end of this I fixt with Wax a good _plano convex_ Object Glass,
+    with the convex side towards the Object, and into the bigger end I fixt
+    also with wax a pretty large plano _Convex_ Glass, with the _convex_
+    side towards my eye, then by means of the small hole by the side, I
+    fill'd the intermediate space between these two Glasses with very clear
+    Water, and with a Screw stopp'd it in; then putting on a Cell for the
+    Eye, I could perceive an Object more bright then I could when the
+    intermediate space was only fill'd with Air, but this, for other
+    inconveniences, I made but little use of.
+
+    My way for fixing both the Glass and Object to the Pedestal most
+    conveniently was thus: Upon one side of a round Pedestal AB, in the
+    sixth Figure of the first _Scheme_, was fixt a small Pillar CC, on this
+    was fitted a small Iron Arm D, which could be mov'd up and down, and
+    fixt in any part of the Pillar, by means of a small Screw E; on the end
+    of this Arm was a small Ball fitted into a kind of socket F, made in
+    the side of the Brass Ring G, through which the small end of the Tube
+    was screw'd; by means of which contrivance I could place and fix the
+    Tube in what posture I desir'd (which for many Observations was
+    exceeding necessary) and adjusten it most exactly to any Object.
+
+    For placing the Object, I made this contrivance; upon the end of a
+    small brass Link or Staple HH, I so fastned a round Plate II, that it
+    might be turn'd round upon its Center K, and going pretty stiff, would
+    stand fixt in any posture it was set; on the side of this was fixt a
+    small Pillar P, about three quarters of an inch high, and through the
+    top of this was thrust a small Iron pin M, whose top just stood over
+    the Center of the Plate; on this top I fixt a small Object, and by
+    means of these contrivances I was able to turn it into all kind of
+    positions, both to my Eye and the Light; for by moving round the small
+    Plate on its center, could move it one way, and by turning the Pin M, I
+    could move it another way, and this without stirring the Glass at all,
+    or at least but very little; the Plate likewise I could move to and fro
+    to any part of the Pedestal (which in many cases was very convenient)
+    and fix it also in any Position, by means of a Nut N, which was screw'd
+    on upon the lower part of the Pillar CC. All the other Contrivances are
+    obvious enough from the draught, and will need no description.
+
+Now though this were the Instrument I made most use of, yet I have made
+several other Tryals with other kinds of Microscopes, which both for
+_matter_ and _form_ were very different from common spherical Glasses. I
+have made a _Microscope_ with one piece of Glass, both whose surfaces were
+_plains_. I have made another only with a _plano concave_, without any kind
+of reflection, divers also by means of _reflection_. I have made others of
+_Waters_, _Gums_, _Resins_, _Salts_, _Arsenick_, _Oyls_, and with divers
+other _mixtures of watery_ and _oyly Liquors_. And indeed the subject is
+capable of a great variety; but I find generally none more useful then that
+which is made with _two Glasses_, such as I have already describ'd.
+
+What the things are I observ'd, the following descriptions will manifest;
+in brief, they were either _exceeding small Bodies_, or _exceeding small
+Pores_, or _exceeding small Motions_, some of each of which the Reader will
+find in the following Notes, and such, as I presume, (many of them at
+least) will be _new_, and perhaps not less _strange_: Some _specimen_ of
+each of which Heads the Reader will find in the subsequent delineations,
+and indeed of some more then I was willing there should be; which was
+occasioned by my first Intentions to print a much greater number then I
+have since found time to compleat. Of such therefore as I had, I selected
+only some few of every Head, which for some particulars seem'd most
+observable, rejecting the rest as superfluous to the present Design.
+
+What each of the delineated Subjects are, the following descriptions
+annext to each will inform, of which I shall here, only once for all, add,
+That in divers of them the Gravers have pretty well follow'd my directions
+and draughts; and that in making of them, I indeavoured (as far as I was
+able) first to discover the true appearance, and next to make a plain
+representation of it. This I mention the rather, because of these kind of
+Objects there is much more difficulty to discover the true shape, then of
+those visible to the naked eye, the same Object seeming quite differing, in
+one position to the Light, from what it really is, and may be discover'd in
+another. And therefore I never began to make any draught before by many
+examinations in several lights, and in several positions to those lights, I
+had discover'd the true form. For it is exceeding difficult in some
+Objects, to distinguish between a _prominency_ and a _depression_, between
+a _shadow_ and a _black stain_, or a _reflection_ and a _whiteness in the
+colour_. Besides, the transparency of most Objects renders them yet much
+more difficult then if they were _opacous_. The Eyes of a Fly in one kind
+of light appear almost like a Lattice, drill'd through with abundance of
+small holes; which probably may be the Reason, why the Ingenious _Dr.
+Power_ seems to suppose them such. In the Sunshine they look like a Surface
+cover'd with golden Nails; in another posture, like a Surface cover'd with
+Pyramids; in another with Cones; and in other postures of quite other
+shapes; but that which exhibits the best, is the Light collected on the
+Object, by those means I have already describ'd.
+
+And this was undertaken in prosecution of the Design which the _ROYAL
+SOCIETY_ has propos'd to it self. For the Members of the Assembly having
+before their eys so many _fatal_ Instances of the errors and falshoods, in
+which the greatest part of mankind has so long wandred, because they rely'd
+upon the strength of humane Reason alone, have begun anew to correct all
+_Hypotheses_ by sense, as Seamen do their _dead Reckonings_ by _Coelestial
+Observations_; and to this purpose it has been their principal indeavour to
+_enlarge & strengthen_ the _Senses_ by _Medicine_, and by such _outward
+Instruments_ as are proper for their particular works. By this means they
+find some reason to suspect, that those effects of Bodies, which have been
+commonly attributed to _Qualities_, and those confess'd to be _occult_, are
+perform'd by the small _Machines_ of Nature, which are not to be discern'd
+without these helps, seeming the meer products of _Motion_, _Figure_, and
+_Magnitude_; and that the _Natural Textures_, which some call the _Plastick
+faculty_, may be made in _Looms_, which a greater perfection of Opticks may
+make discernable by these Glasses; so as now they are no more puzzled about
+them, then the vulgar are to conceive, how _Tapestry_ or _flowred Stuffs_
+are woven. And the ends of all these Inquiries they intend to be the
+_Pleasure_ of Contemplative minds, but above all, the _ease and dispatch_
+of the labours of mens hands. They do indeed neglect no opportunity to
+bring all the _rare_ things of Remote Countries within the compass of their
+knowledge and practice. But they still acknowledg their _most useful_
+Informations to arise from _common_ things, and from _diversifying_ their
+most _ordinary_ operations upon them. They do not wholly reject Experiments
+of meer _light_ and _theory_; but they principally aim at such, whose
+Applications will _improve and facilitate_ the present way of _Manual
+Arts_. And though some men, who are perhaps taken up about less honourable
+Employments, are pleas'd to censure their proceedings, yet they can shew
+more _fruits_ of their first three years, wherein they have assembled, then
+any other _Society_ in _Europe_ can for a much larger space of time. 'Tis
+true, such undertakings as theirs do commonly meet with small
+incouragement, because men are generally rather taken with the _plausible_
+and _discursive_, then the _real_ and the solid part of Philosophy; yet by
+the good fortune of their institution, in an Age of all others the most
+_inquisitive_, they have been assisted by the _contribution_ and _presence_
+of very many of the chief _Nobility_ and _Gentry_, and others who are some
+of the _most considerable_ in their several Professions. But that that yet
+farther convinces me of the _Real esteem_ that the more _serious_ part of
+men have of this _Society_, is, that several _Merchants_, men who act in
+earnest (whose Object is _meum & tuum_, that great _Rudder_ of humane
+affairs) have adventur'd considerable sums of _Money_, to put in practice
+what some of our Members have contrived, and have continued _stedfast_ in
+their good opinions of such Indeavours, when not one of a hundred of the
+vulgar have believed their undertakings feasable. And it it also fit to be
+added, that they have one advantage peculiar to themselves, that very many
+of their number are _men of Converse and Traffick_; which is a good Omen,
+that their attempts will bring Philosophy from _words_ to _action_, seeing
+the men of Business have had so great a share in their first foundation.
+
+And of this kind I ought not to conceal one particular _Generosity_, which
+more nearly concerns my self. It is the _munificence_ of _Sir John Cutler_,
+in endowing a Lecture for the promotion of _Mechanick Arts_, to be governed
+and directed by This _Society._This _Bounty_ I mention for the
+_Honourableness_ of the thing it self, and for the expectation which I have
+of the _efficacy_ of the _Example_; for it cannot now be objected to them,
+that their Designs will be esteemed _frivolous_ and _vain_, when they have
+such a _real Testimony_ of the _Approbation_ of a _Man_ that is such an
+_eminent Ornament_ of this renowned City, and one, who, by the _Variety_,
+and the _happy Success_, of his negotiations, has given evident proofs,
+that he is not easie to be deceiv'd. This Gentleman has well observ'd, that
+the _Arts_ of life have been too long _imprison'd_ in the dark shops of
+Mechanicks themselves, & there _hindred from growth_, either by ignorance,
+or self-interest: and he has bravely _freed_ them from these
+_inconveniences_: He hath not only obliged _Tradesmen_, but _Trade_ it
+self: He has done a work that is worthy of _London_, and has taught the
+chief City of Commerce in the world the right way how Commerce is to be
+improv'd. We have already seen many other great signs of Liberality and a
+large mind, from the same hand: For by his _diligence_ about the
+_Corporation for the Poor_; by his honorable _Subscriptions_ for the
+rebuilding of St. Paul's; by his chearful _Disbursment_ for the replanting
+of _Ireland_, and by many other such _publick works_, he has shewn by what
+means he indeavours to _establish_ his Memory; and now by this last gift he
+has done that, which became one of the _wisest Citizens_ of our Nation to
+accomplish, seeing one of the _wisest of our Statesmen, the Lord Verulam_,
+first propounded it.
+
+But to return to my Subject, from a digression, which, I hope, my Reader
+will pardon me, seeing the Example is so rare that I can make no more such
+digressions. If these my first Labours shall be any wayes useful to
+inquiring men, I must attribute the incouragement and promotion of them to
+a very _Reverend_ and _Learned Person_, of whom this ought in justice to be
+said, _That there is scarce any one Invention, which this Nation has
+produc'd in our Age, but it has some way or other been set forward by his
+assistance_. My Reader, I believe, will quickly ghess, that it is _Dr.
+Wilkins_ that I mean. He is indeed a man born for the _good_ of _mankind_,
+and for the _honour_ of his _Country_. In the _sweetness_ of whose
+_behaviour_, in the _calmness_ of his _mind_, in the _unbounded goodness_
+of his _heart_, we have an evident Instance, what the true and the
+_primitive unpassionate Religion_ was, before it was _sowred_ by particular
+_Factions._ In a word, his _Zeal_ has been so _constant_ and _effectual_ in
+advancing all good and profitable _Arts, that_ as one of the Antient
+_Romans_ said of _Scipio_, _That he thanked God that he was a _Roman_;
+because whereever _Scipio_ had been born, there had been the seat of the
+Empire of the world_: So may I thank God, that _Dr. Wilkins_ was an
+_Englishman_, for whereever he had lived, there had been the chief Seat of
+_generous Knowledge_ and _true Philosophy_. To the truth of this, there are
+so many worthy men living that will subscribe, that I am confident, what I
+have here said, will not be looked upon, by any ingenious Reader, as a
+_Panegyrick_, but only as a _real testimony_.
+
+By the Advice of this _Excellent man_ I first set upon this Enterprise,
+yet still came to it with much _Reluctancy_, because I was to follow the
+footsteps of so eminent a Person as _Dr. Wren_, who was the first that
+attempted any thing of this nature; whose original draughts do now make one
+of the Ornaments of that great Collection of Rarities in the _Kings
+Closet_. This _Honor_, which his first beginnings of this kind have
+receiv'd, to be admitted into the most famous place of the world, did not
+so much _incourage_, as the _hazard_ of coming after _Dr. Wren_ did
+_affright_ me; for of him I must, affirm, that, since the time of
+_Archimedes_, there scarce ever met in one man, in so great a perfection,
+such a _Mechanical Hand_, and so _Philosophical_ a _Mind_.
+
+But at last, being assured both by _Dr. Wilkins_, and _Dr. Wren_ himself,
+that he had given over his intentions of prosecuting it, and not finding
+that there was any else design'd the pursuing of it, I set upon this
+undertaking, and was not a little incourag'd to proceed in it, by the
+Honour the _Royal Society_ was pleas'd to favour me with, in approving of
+those draughts (which from time to time as I had an opportunity of
+describing) I presented to them. And particularly by the Incitements of
+divers of those Noble and excellent Persons of it, which were my more
+especial Friends, who were not less urgent with me for the publishing, then
+for the prosecution of them.
+
+After I had almost compleated these Pictures and Observations (having had
+divers of them ingraven, and was ready to send them to the Press) I was
+inform'd, that the Ingenious Physitian _Dr. Henry Power_ had made several
+_Microscopical_ Observations, which had I not afterwards, upon our
+interchangably viewing each others Papers, found that they were for the
+most part differing from mine, either in the Subject it self, or in the
+particulars taken notice of; and that his design was only to print
+Observations without Pictures, I had even then _suppressed_ what I had so
+far proceeded in. But being further _excited_ by several of my Friends, in
+complyance with their opinions, that it would not be unacceptable to
+several inquisitive Men, and hoping also, that I should thereby discover
+something New to the World, I have at length cast in my Mite, into the vast
+Treasury of _A Philosophical History_. And it is my _hope_, as well as
+_belief_, that these my _Labours_ will be no more comparable to the
+_Productions_ of many other _Natural Philosophers_, who are now every where
+busie about _greater_ things; then my _little Objects_ are to be compar'd
+to the greater and more beautiful _Works of Nature_, A Flea, a Mite, a
+Gnat, to an Horse, an Elephant, or a Lyon.
+
+
+       *       *       *       *       *
+
+
+MICROGRAPHIA,
+
+OR SOME
+
+Physiological Descriptions
+
+OF
+
+MINUTE BODIES,
+
+MADE BY
+
+MAGNIFYING GLASSES;
+
+WITH
+
+OBSERVATIONS and INQUIRIES thereupon.
+
+       *       *       *       *       *
+
+
+Observ. I. _Of the Point of a sharp small Needle._
+
+As in _Geometry_, the most natural way of beginning is from a Mathematical
+_point_; so is the same method in Observations and _Natural history_ the
+most genuine, simple, and instructive. We must first endevour to make
+_letters_, and draw _single_ strokes true, before we venture to write whole
+_Sentences_, or to draw large _Pictures_. And in _Physical_ Enquiries, we
+must endevour to follow Nature in the more _plain_ and _easie_ ways she
+treads in the most _simple_ and _uncompounded bodies_, to trace her steps,
+and be acquainted with her manner of walking there, before we venture our
+selves into the multitude of _meanders_ she has in _bodies of a more
+complicated_ nature; lest, being unable to distinguish and judge of our
+way, we quickly lose both _Nature_ our Guide, and _our selves_ too, and are
+left to wander in the _labyrinth_ of groundless opinions; wanting both
+_judgment_, that _light_, and _experience_, that _clew_, which should
+direct our proceedings.
+
+We will begin these our Inquiries therefore with the Observations of Bodies
+of the most _simple nature_ first, and so gradually proceed to those of a
+more _compounded_ one. In prosecution of which method, we shall begin with
+a _Physical point_; of which kind the _Point of a Needle_ is commonly
+reckon'd for one; and is indeed, for the most part, made so sharp, that the
+naked eye cannot distinguish any parts of it: It very easily pierces, and
+makes its way through all kind of bodies softer then it self: But if view'd
+with a very good _Microscope_, we may find that the _top_ of a Needle
+(though as to the sense very _sharp_) appears a _broad_, _blunt,_ and very
+_irregular_ end; not resembling a Cone, as is imagin'd, but onely a piece
+of a tapering body, with a great part of the top remov'd, or deficient. The
+Points of Pins are yet more blunt, and the Points of the most curious
+Mathematical Instruments do very seldome arrive at so great a sharpness;
+how much therefore can be built upon demonstrations made onely by the
+productions of the Ruler and Compasses, he will be better able to consider
+that shall but view those _points_ and _lines_ with a _Microscope_.
+
+Now though this point be commonly accounted the sharpest (whence when we
+would express the sharpness of a point the most _superlatively_, we say, As
+sharp as a Needle) yet the _Microscope_ can afford us hundreds of Instances
+of Points many thousand times sharper: such as those of the _hairs_, and
+_bristles_, and _claws_ of multitudes of _Insects_; the _thorns_, or
+_crooks_, or _hairs_ of _leaves_, and other small vegetables; nay, the ends
+of the _stiriæ_ or small _parallelipipeds_ of _Amianthus_, and _alumen
+plumosum_; of many of which, though the Points are so sharp as not to be
+visible, though view'd with a _Microscope_ (which magnifies the Object, in
+bulk, above a million of times) yet I doubt not, but were we able
+_practically_ to make _Microscopes_ according to the _theory_ of them, we
+might find hills, and dales, and pores, and a sufficient bredth, or
+expansion, to give all those parts elbow-room, even in the blunt top of the
+very Point of any of these so very sharp bodies. For certainly the
+_quantity_ or extension of any body may be _Divisible in infinitum_, though
+perhaps not the _matter_.
+
+But to proceed: The Image we have here exhibited in the first Figure[1],
+was the top of a small and very sharp Needle, whose point _aa_ nevertheless
+appear'd through the _Microscope_ above a quarter of an inch broad, not
+round nor flat, but _irregular_ and _uneven_; so that it seem'd to have
+been big enough to have afforded a hundred armed Mites room enough to be
+rang'd by each other without endangering the breaking one anothers necks,
+by being thrust off on either side. The surface of which, though appearing
+to the naked eye very smooth, could not nevertheless hide a multitude of
+holes and scratches and ruggednesses from being discover'd by the
+_Microscope_ to invest it, several of which inequalities (as A, B, C,
+seem'd _holes_ made by some small specks of _Rust_; and D some
+_adventitious body_, that stuck very close to it) were _casual_. All the
+rest that roughen the surface, were onely so many marks of the rudeness and
+bungling of _Art_. So unaccurate is it, in all its productions, even in
+those which seem most neat, that if examin'd with an organ more acute then
+that by which they were made, the more we see of their _shape_, the less
+appearance will there be of their _beauty_: whereas in the works of
+_Nature_, the deepest Discoveries shew us the greatest Excellencies. An
+evident Argument, that he that was the Author of all these things, was no
+other then _Omnipotent_; being able to include as great a variety of parts
+and contrivances in the yet smallest Discernable Point, as in those vaster
+bodies (which comparatively are called also Points) such as the _Earth_,
+_Sun_, or _Planets_. Nor need it seem strange that the Earth it self may be
+by _Analogie_ call'd a Physical Point: For as its body, though now so near
+us as to fill our eys and fancies with a sense of the vastness of it, may
+by a little Distance, and some convenient _Diminishing_ Glasses, be made
+vanish into a scarce visible Speck, or Point (as I have often try'd on the
+_Moon_, and (when not too bright) on the _Sun_ it self.) So, could a
+Mechanical contrivance succesfully answer our _Theory_, we might see the
+least spot as big as the Earth it self; and Discover, as _Des Cartes_[2]
+also conjectures, as great a variety of bodies in the _Moon_, or _Planets_,
+as in the _Earth_.
+
+But leaving these Discoveries to future Industries, we shall proceed to add
+one Observation more of a _point_ commonly so call'd, that is, the mark of
+a _full stop_, or _period_. And for this purpose I observed many both
+_printed_ ones and _written_; and among multitudes I found _few_ of them
+more _round_ or _regular_ then this which I have delineated in the third
+figure of the second Scheme, but _very many_ abundantly _more disfigur'd_;
+and for the most part if they seem'd equally round to the eye, I found
+those points that had been made by a _Copper-plate,_ and Roll-press, to be
+as misshapen as those which had been made with _Types_, the most curious
+and smothly _engraven strokes_ and _points_, looking but as so many
+_furrows_ and _holes_, and their _printed impressions_, but like _smutty
+daubings_ on a matt or uneven floor with a blunt extinguisht brand or
+stick's end. And as for _points_ made with a _pen_ they were much _more
+ragged_ and _deformed_. Nay, having view'd certain pieces of exceeding
+curious writing of the kind (one of which in the bredth of a _two-pence_
+compris'd _the Lords prayer, the Apostles Creed, the ten Commandments, and
+about half a dozen verses besides of the Bible_, whose _lines_ were _so
+small_ and _near together_, that I was unable to _number_ them with my
+_naked eye_,) a very ordinary _Microscope_, I had then about me, inabled me
+to see that what the Writer of it had asserted was _true_, but withall
+discover'd of what pitifull _bungling scribbles_ and _scrawls_ it was
+compos'd, _Arabian_ and _China characters_ being almost as well shap'd, yet
+thus much I must say for the Man, that it was for the most part _legible_
+enough, though in some places there wanted a good _fantsy_ well _preposest_
+to help one through. If this manner _of small writing_ were made _easie_
+and _practicable_ (and I think I know such a one, but have never yet made
+tryal of it, whereby one might be inabled to write _a great deale_ with
+_much ease_, and _accurately_ enough in a very _little roome_) it might be
+of very good use to convey _secret Intelligence_ without any danger of
+_Discovery_ or _mistrusting_. But to come again to the point. The
+_Irregularities_ of it are caused by three or four _coadjutors_, one of
+which is, the _uneven surface_ of the _paper_, which at best appears no
+smother then a very course piece of _shag'd cloth_, next the _irregularity
+of the Type_ or _Ingraving_, and a third is the _rough Daubing_ of the
+_Printing-Ink_ that lies upon the instrument that makes the impression, to
+all which, add the _variation_ made by the Different _lights_ and
+_shadows_, and you may have sufficient reason to guess that a _point_ may
+appear much more _ugly_ then _this_, which I have here presented, which
+though it appear'd through the _Microscope_ _gray_, like a great splatch of
+_London_ dirt, about three inches over; yet to the _naked eye_ it was
+_black_ and no bigger then that in the midst of the Circle A. And could I
+have found Room in this Plate to have inserted an O you should have seen
+that the _letters_ were not more distinct then the _points_ of Distinction,
+nor a _drawn circle_ more exactly _so_, then we have now shown a _point_ to
+be a _point_.
+
+       *       *       *       *       *
+
+
+Observ. II. _Of the Edge of a Razor._
+
+The sharpest _Edge_ hath the same kind of affinity to the sharpest _Point_
+in Physicks, as a _line_ hath to a _point_ in Mathematicks; and therefore
+the Treaty concerning this, may very properly be annexed to the former. A
+Razor doth appear to be a Body of a very neat and curious aspect, till more
+closely viewed by the _Microscope_, and there we may observe its very Edge
+to be of all kind of shapes, except what it should be. For examining that
+of a very sharp one, I could not find that any part of it had any thing of
+sharpness in it; but it appeared a rough surface of a very considerable
+bredth from side to side, the narrowest part not seeming thinner then the
+back of a pretty thick Knife. Nor is't likely that it should appear any
+otherwise, since as we just now shew'd that a _point_ appear'd a _circle_,
+'tis rational a _line_ should be a _parallelogram_.
+
+Now for the drawing this second Figure[3] (which represents a part of the
+Edge about half a quarter of an inch long of a Razor well set) I so plac'd
+it between the Object-glass & the light, that there appear'd a reflection
+from the very Edge, represented by the white line abcdef. In which you may
+perceive it to be somewhat sharper then elsewhere about d, to be indented
+or pitted about b, to be broader and thicker about c, and unequal and
+rugged about e, and pretty even between ab and ef. Nor was that part of the
+Edge ghik so smooth as one would imagine so smooth bodies as a Hone and Oyl
+should leave it; for besides those multitudes of scratches, which appear to
+have raz'd the surface ghik, and to cross each other every way which are
+not half of them exprest in the Figure, there were several great and deep
+scratches, or furrows, such as gh and ik, which made the surface yet more
+rugged, caus'd perhaps by some small Dust casually falling on the Hone, or
+some harder or more flinty part of the Hone it self. The other part of the
+Razor ll, which is polish'd on a grinding-stone, appear'd much rougher then
+the other, looking almost like a plow'd field, with many parallels, ridges,
+and furrows, and a cloddy, as 'twere, or an uneven surface: nor shall we
+wonder at the roughnesses of those surfaces, since even in the most curious
+wrought Glasses for _Microscopes_, and other Optical uses, I have, when the
+Sun has shone well on them, discover'd their surface to be variously raz'd
+or scratched, and to consist of an infinite of small broken surfaces, which
+reflect the light of very various and differing colours. And indeed it
+seems impossible by Art to cut the surface of any hard and brittle body
+smooth, since _Putte_, or even the most curious _Powder_ that can be made
+use of, to polish such a body, must consist of little hard rough particles,
+and each of them must cut its way, and consequently leave some kind of
+gutter or furrow behind it. And though Nature does seem to do it very
+readily in all kinds of fluid bodies, yet perhaps future observators may
+discover even these also rugged; it being very probable, as I elsewhere
+shew, that fluid bodies are made up of small solid particles variously and
+strongly mov'd, and may find reason to think there is scarce a surface _in
+rerum naturâ_ perfectly smooth. The black spot mn, I ghess to be some small
+speck of rust, for that I have oft observ'd to be the manner of the working
+of Corrosive Juyces. To conclude, this Edge and piece of a Razor, if it had
+been really such as it appear'd through the _Microscope_, would scarcely
+have serv'd to cleave wood, much less to have cut off the hair of beards,
+unless it were after the manner that _Lucian_ merrily relates _Charon_ to
+have made use of, when with a Carpenters Axe he chop'd off the beard of a
+sage Philosopher, whose gravity he very cautiously fear'd would indanger
+the oversetting of his Wherry.
+
+       *       *       *       *       *
+
+
+Observ. III. _Of fine Lawn, or Linnen Cloth._
+
+This is another product of Art, A piece of the finest Lawn I was able to
+get, so curious that the threads were scarce discernable by the naked eye,
+and yet through an ordinary _Microscope_ you may perceive[4] what a goodly
+piece of _coarse Matting_ it is; what proportionable cords each of its
+threads are, being not unlike, both in shape and size, the bigger and
+coarser kind of _single Rope-yarn_, wherewith they usually make _Cables_.
+That which makes the Lawn so transparent, is by the _Microscope_, nay by
+the naked eye, if attentively viewed, plainly enough evidenced to be the
+multitude of square holes which are left between the threads, appearing to
+have much more hole in respect of the intercurrent parts then is for the
+most part left in a _lattice-window_, which it does a little resemble,
+onely the crossing parts are round and not flat.
+
+These threads that compose this fine contexture, though they are as small
+as those that constitute the finer sorts of Silks, have notwithstanding
+nothing of their glossie, pleasant, and lively reflection. Nay, I have been
+informed both by the Inventor himself, and several other eye-witnesses,
+that though the flax, out of which it is made, has been (by a singular art,
+of that excellent Person, and Noble Vertuoso, M. _Charls Howard_, brother
+to the _Duke of Norfolk_) so curiously dress'd and prepar'd, as to appear
+both to the eye and the touch, full as _fine_ and as _glossie_, and to
+receive all kinds of colours, as well as Sleave-Silk; yet when this Silken
+Flax is twisted into threads, it quite loseth its former luster, and
+becomes as plain and base a thread to look on, as one of the same bigness,
+made of common Flax.
+
+The reason of which odd _Phenomenon_ seems no other then this; that though
+the curiously drest Flax has its parts so exceedingly small, as to
+equallize, if not to be much smaller then the clew of the Silk-worm,
+especially in thinness, yet the differences between the figures of the
+constituting filaments are so great, and their substances so various, that
+whereas those of the _Silk_ are _small_, _round_, _hard_, _transparent,_
+and to their bigness proportionably _stiff_, so as each filament preserves
+its proper _Figure_, and consequently its vivid _reflection_ intire, though
+twisted into a thread, if not too hard; those of Flax are _flat_, _limber_,
+_softer,_ and _less transparent_, and in twisting into a thread they joyn,
+and lie so close together, as to lose their own, and destroy each others
+particular reflections. There seems therefore three Particulars very
+requisite to make the so drest Flax appear Silk also when spun into
+threads. First, that the substance of it should be made more _clear_ and
+_transparent_, Flax retaining in it a kind of opacating brown, or yellow;
+and the parts of the whitest kind I have yet observ'd with the _Microscope_
+appearing white, like flaw'd Horn or Glass, rather then clear, like clear
+Horn or Glass. Next that, the filaments should each of them be _rounded_,
+if that could be done, which yet is not so very necessary, if the first be
+perform'd, and this third, which is, that each of the small filaments be
+_stifned_; for though they be square, or flat, provided they be
+_transparent_ and stiff, much the same appearances must necessarily follow.
+Now, though I have not yet made trial, yet I doubt not, but that both these
+proprieties may be also induc'd upon the Flax, and perhaps too by one and
+the same Expedient, which some trials may quickly inform any ingenious
+attempter of, who from the use and profit of such an Invention, may find
+sufficient argument to be prompted to such Inquiries. As for the _tenacity_
+of the substance of Flax, out of which the thread is made, it seems much
+inferiour to that of Silk, the one being a _vegetable_, the other an
+_animal_ substance. And whether it proceed from the better concoction, or
+the more homogeneous constitution of _animal_ substances above those of
+_vegetables_, I do not here determine; yet since I generally find, that
+_vegetable_ substances do not equalize the _tenacity_ of _animal_, nor
+these the _tenacity_ of some purified _mineral_ substances; I am very apt
+to think, that the _tenacity_ of bodies does not proceed from the _hamous_,
+or _hooked_ particles, as the _Epicureans_ and some modern _Philosophers_
+have imagin'd; but from the more exact _congruity_ of the constituent
+parts, which are contiguous to each other, and so bulky, as not to be
+easily separated, or shatter'd, by any small pulls or concussion of heat.
+
+       *       *       *       *       *
+
+
+Observ. IV. _Of fine waled Silk, or Taffety._
+
+This[5] is the appearance of a piece of very fine Taffety-riband in the
+bigger magnifying Glass, which you see exhibits it like a very convenient
+substance to make Bed-matts, or Door-matts of, or to serve for Beehives,
+Corn-scuttles, Chairs, or Corn-tubs, it being not unlike that kind of work,
+wherewith in many parts in _England_, they make such Utensils of Straw, a
+little wreathed, and bound together with thongs of Brambles. For in this
+Contexture, each little filament, fiber, or clew of the Silk-worm, seem'd
+about the bigness of an ordinary Straw, as appears by the little irregular
+pieces, ab, cd, and ef; The _Warp_, or the thread that ran crossing the
+Riband, appear'd like a single Rope of an Inch Diameter; but the _Woof_, or
+the thread that ran the length of the Riband, appear'd not half so big.
+Each Inch of six-peny-broad Riband appearing no less then a piece of
+Matting Inch and half thick, and twelve foot square, a few yards of this,
+would be enough to floor the long Gallery of the _Loure_ at _Paris_. But to
+return to our piece of Riband: It affords us a not unpleasant object,
+appearing like a bundle, or wreath, of very clear and transparent
+_Cylinders_, if the Silk be white, and curiously ting'd; if it be colour'd,
+each of those small horney _Cylinders_ affording in some place or other of
+them, as vivid a reflection, as if it had been sent from a _Cylinder_ of
+Glass or Horn. In-so-much, that the reflexions of Red, appear'd as if
+coming from so many _Granates_, or _Rubies_. The loveliness of the colours
+of Silks above those of hairy Stuffs, or Linnen, consisting, as I
+else-where intimate, chiefly in the transparency, and vivid reflections
+from the _Concave_, or inner surface of the _transparent Cylinder_, as are
+also the colours of Precious Stones; for most of the reflections from each
+of these _Cylinders_, come from the _Concave_ surface of the air, which is
+as 'twere the foil that incompasses the _Cylinder_. The colours with which
+each of these _Cylinders_ are ting'd, seem partly to be superficial, and
+sticking to the out-sides of them; and partly, to be imbib'd, or sunck into
+the substance of them: for Silk, seeming to be little else then a dried
+thread of Glew, may be suppos'd to be very easily relaxt, and softened, by
+being steeped in warm, nay in cold, if penetrant, juyces or liquors. And
+thereby those tinctures, though they tinge perhaps but a small part of the
+substance, yet being so highly impregnated with the colour, as to be almost
+black with it, may leave an impression strong enough to exhibite the
+desir'd colour. A pretty kinde of artificial Stuff I have seen, looking
+almost like transparent Parchment, Horn, or Ising-glass, and perhaps some
+such thing it may be made of, which being transparent, and of a glutinous
+nature, and easily mollified by keeping in water, as I found upon trial,
+had imbib'd, and did remain ting'd with a great variety of very vivid
+colours, and to the naked eye, it look'd very like the substance of the
+Silk. And I have often thought, that probably there might be a way found
+out, to make an artificial glutinous composition, much resembling, if not
+full as good, nay better, then that Excrement, or whatever other substance
+it be out of which, the Silk-worm wire-draws his clew. If such a
+composition were found, it were certainly an easie matter to find very
+quick ways of drawing it out into small wires for use. I need not mention
+the use of such an Invention, nor the benefit that is likely to accrue to
+the finder, they being sufficiently obvious. This hint therefore, may, I
+hope, give some Ingenious inquisitive Person an occasion of making some
+trials, which if successfull, I have my aim, and I suppose he will have no
+occasion to be displeas'd.
+
+       *       *       *       *       *
+
+
+Observ. V. _Of watered Silks, or Stuffs._
+
+There are but few _Artificial_ things that are worth observing with a
+_Microscope_, and therefore I shall speak but briefly concerning them. For
+the Productions of art are such rude mis-shapen things, that when view'd
+with a _Microscope_, is little else observable, but their deformity. The
+most curious Carvings appearing no better then those rude _Russian_ Images
+we find mention'd in _Purchas_, where three notches at the end of a Stick,
+stood for a face. And the most smooth and burnish'd surfaces appear most
+rough and unpolisht: So that my first Reason why I shall add but a few
+observations of them, is, their mis-shapen form; and the next, is their
+uselessness. For why should we trouble our selves in the examination of
+that form or shape (which is all we are able to reach with a _Microscope_)
+which we know was design'd for no higher a use, then what we were able to
+view with our naked eye? Why should we endeavour to discover mysteries in
+that which has no such thing in it? And like _Rabbins_ find out
+_Caballisms_, and _ænigmâs_ in the Figure, and placing of Letters, where no
+such thing lies hid: whereas in _natural_ forms there are some so small,
+and so curious, and their design'd business so far remov'd beyond the reach
+of our sight, that the more we magnify the object, the more excellencies
+and mysteries do appear; And the more we discover the imperfections of our
+senses; and the Omnipotency and Infinite perfections of the great Creatour.
+I shall therefore onely add one or two Observations more _artificial_
+things, and then come to the Treaty concerning such matters as are the
+Productions of a more curious Workman. One of these, shall be that of a
+piece of water'd Silk, represented in the second Figure of the third
+_Scheme_,[6] as it appear'd through the least magnifying Glass. _AB_
+signifying the long way of the Stuff, and _CD_ the broad way. This Stuff,
+if the right side of it be looked upon, appears to the naked eye, all over
+so waved, undulated, or grain'd, with a curious, though irregular variety
+of brighter and darker parts, that it adds no small gracefulness to the
+Gloss of it. It is so known a propriety, that it needs but little
+explication, but it is observable, which perhaps everyone has not
+considered, that those parts which appear the darker part of the wave, in
+one position to the light, in another appears the lighter, and the
+contrary; and by this means the undulations become transient, and in a
+continual change, according as the position of the parts in respect of the
+incident beams of light is varied. The reason of which odd _phænomena_, to
+one that has but diligently examin'd it even with his naked eye, will be
+obvious enough. But he that observes it with a _Microscope_, may more
+easily perceive what this _Proteus_ is, and how it comes to change its
+shape. He may very easily perceive, that it proceeds onely from the variety
+of the _Reflections_ of light, which is caus'd by the various _shape of the
+Particles_, or little protuberant parts of the thread that compose the
+surface; and that those parts of the waves that appear the brighter, throw
+towards the eye a multitude of small reflections of light, whereas the
+darker scarce afford any. The reason of which reflection, the _Microscope_
+plainly discovers, as appears by the Figure. In which you may perceive,
+that the brighter parts of the surface consist of an abundance of large and
+strong reflections, denoted by a, a, a, a, a, &c. for the surfaces of those
+threads that run the _long way_, are by the Mechanical process of watering,
+_creas'd_ or _angled_ in another kind of posture then they were by the
+weaving: for by the weaving they are onely _bent round_ the warping
+threads; but by the watering, they are _bent with an angle, or elbow_, that
+is in stead of lying, or being bent _round_ the threads, as in the third
+Figure, a, a, a, a, a, are about b, b, b (b, b, b representing the ends, as
+'twere, of the cross threads, they are bent about) they are creas'd on the
+top of those threads, with an _angle_, as in the fourth Figure, and that
+with all imaginable variety; so that, whereas before they reflected the
+light onely from one point of the round surface, as about c, c, c, they now
+when water'd, reflect the beams from more then half the whole surface, as
+de, de, de, and in other postures they return no reflections at all from
+those surfaces. Hence in one posture they compose the brighter parts of the
+waves, in another the darker. And these reflections are also varied,
+according as the particular parts are variously bent. The reason of which
+creasing we shall next examine; and here we must fetch our information from
+the Mechanism or manner of proceeding in this operation; which, as I have
+been inform'd, is no other then this.
+
+They double all the Stuff that is to be water'd, that is, they crease it
+just through the middle of it, the whole length of the piece, leaving the
+right side of the Stuff inward, and placing the two edges, or silvages just
+upon one another, and, as near as they can, place the wale so in the
+doubling of it, that the wale of the one side may lie very near parallel,
+or even with the wale of the other; for the nearer that posture they lie,
+the greater will the watering appear; and the more obliquely, or across to
+each other they lie, the smaller are the waves. Their way for folding it
+for a great wale is thus: they take a Pin, and begin at one side of the
+piece in any wale, and so moving it towards the other side, thereby direct
+their hands to the opposite ends of the wale, and then, as near as they
+can, place the two opposite ends of the same wale together, and so double,
+or fold the whole piece, repeating this enquiry with a Pin at every yard or
+two's distance through the whole length; then they sprinkle it with water,
+and fold it the longways, placing between every fold a piece of Pastboard,
+by which means all the wrong side of the water'd Stuff becomes flat, and
+with little wales, and the wales on the other side become the more
+protuberant; whence the creasings or angular bendings of the wales become
+the more perspicuous. Having folded it in this manner, they place it with
+an interjacent Pastboard into an hot Press, where it is kept very violently
+prest, till it be dry and stiff; by which means, the wales of either
+contiguous sides leave their own impressions upon each other, as is very
+manifest by the second Figure, where 'tis obvious enough, that the wale of
+the piece ABCD runs parallel between the pricked lines ef, ef, ef, and as
+manifest to discern the impressions upon these wales, left by those that
+were prest upon them, which lying not exactly parallel with them, but a
+little athwart them, as is denoted by the lines of, oooo, gh, gh, gh,
+between which the other wales did lie parallel; they are so variously, and
+irregularly creas'd that being put into that shape when wet, and kept so
+till they be drie, they so let each others threads, that the Moldings
+remain almost as long as the Stuff lasts.
+
+Hence it may appear to any one that attentively considers the Figure, why
+the parts of the wale a, a, a, a, a, a, should appear bright; and why the
+parts b, b, b, b, b, b, b, should appear shadowed, or dark; why some, as d,
+d, d, d, d, d, should appear partly light, and partly dark: the varieties
+of which reflections and shadows are the only cause of the appearance of
+watering in Silks, or any other kind of Stuffs.
+
+From the variety of reflection, may also be deduc'd the cause why a small
+breez or gale of wind ruffling the surface of a smooth water, makes it
+appear black; as also, on the other side, why the smoothing or burnishing
+the surface of whitened Silver makes it look black; and multitudes of other
+phænomena might hereby be solv'd, which are too many to be here insisted
+on.
+
+       *       *       *       *       *
+
+
+Observ. VI. _Of Small Glass Canes._
+
+That I might be satisfied, whether it were not possible to make an
+_Artificial_ pore as _small_ as any _Natural_ I had yet found, I made
+several attemps with small _glass pipes_, melted in the flame of a Lamp,
+and then very _suddenly_ drawn out into a great length. And, by _that
+means_, without much difficulty, I was able to draw some almost as small as
+a _Cobweb_, which yet, with the _Microscope_, I could plainly perceive[7]
+to be _perforated_, both by looking on the _ends_ of it, and by looking on
+it _against the light_ which was much the _easier way_ to determine whether
+it were solid or perforated; for, taking a small pipe of glass, and closing
+one end of it, then filling it _half full_ of water, and holding it
+_against the light_, I could, by this means, very easily find what was the
+_differing aspect_ of a _solid_ and a _perforated_ piece of glass; and so
+easily distingish, without seeing either end, whether any _Cylinder_ of
+glass I look'd on, were a _solid stick_, or a _hollow cane_. And by this
+means, I could also presently judge of any small _filament_ of glass,
+whether it were _hollow_ or _not_, which would have been exceeding tedious
+to examine by looking on the end. And many such like ways I was fain to
+make use of, in the examining of divers other particulars related in this
+Book, which would have been no easie task to have determined meerly by the
+more common way of looking on, or viewing the Object. For, if we consider
+first, the very _faint light_ wherewith the object is enlightened, whence
+many particles appear _opacous_, which when more enlightned, appear very
+_transparent_, so that I was fain to _determine_ its _transparency_ by one
+glass, and its _texture_ by another. Next, the _unmanageableness_ of most
+_Objects_, by reason of their _smalness_, 3. The _difficulty of finding_
+the desired point, and of _placing_ it so, as to reflect the _light
+conveniently_ for the Inquiry. Lastly, ones being able to view it but with
+_one eye_ at once, they will appear no small _obstructions_, nor are they
+easily _remov'd_ without many _contrivances_. But to proceed, I could not
+find that water, or some _deeply ting'd_ liquors would in small ones rise
+so high as one would expect; and the _highest_ I have found it yet rise in
+any of the pipes I have try'd, was to 21 _inches_ above the level of the
+water in the vessel: for though I found that in the small pipes it would
+_nimbly enter_ at first, and run about 6 or 7 _inches_ upwards; yet I found
+it then to move upwards _so slow_, that I have not yet had the _patience_
+to observe it above that height of 21 _inches_ (and that was in a pretty
+_large Pipe_, in comparison of those I formerly mentioned; for I could
+observe the _progress_ of a _very deep ting'd liquor_ in it with my _naked
+eye_, without much trouble; whereas many of the _other pipes_ were so _very
+small_, that unless in a _convenient posture_ to the light, I could not
+perceive _them_:) But 'tis very probable, that a greater _patience_ and
+_assiduity_ may discover the liquors to _rise_, at least to remain
+_suspended_, at heights that I should be loath now even to _ghess_ at, if
+at least there be any _proportion_ kept between the height of the ascending
+liquor, and the _bigness of the holes_ of the pipes.
+
+_AN ATTEMPT FOR THE EXPLICATION OF THIS EXPERIMENT._
+
+My Conjecture, _That the unequal height of the surfaces of the water,
+proceeded from the greater pressure made upon the water by the Air without
+the Pipes_ ABC, _then by that within them_[8]; I shall endeavour to confirm
+from the truth of the two following _Propositions_:
+
+The first of which is, _That an unequal pressure of the incumbent Air, will
+cause an unequal height in the water's Surfaces_.
+
+And the second is, _That in this experiment there is such an unequal
+pressure_.
+
+That the first is true, the following _Experiment_ will evince. For if you
+take any Vessel so contrived, as that you can at pleasure either _increase_
+or _diminish_ the _pressure_ of the Air upon this or that part of the
+_Superficies_ of the _water_, the _equality_ of the height of those parts
+will presently be _lost_; and that part of the _Superficies_ that sustains
+the _greater pressure_, will be _inferior_ to that which undergoes the
+_less_. A fit Vessel for this purpose, will be an inverted Glass _Syphon_,
+such an one as is described in the _Sixth Figure_. For if into it you put
+Water enough to fill it as high as _AB_, and gently blow in at _D_, you
+shall _depress_ the Superficies _B_, and thereby _raise_ the opposite
+Superficies _A_ to a _considerable height_, and by gently _sucking_ you may
+produce clean _contrary_ effects.
+
+Next, That there is such an _unequal pressure_, I shall prove from this,
+_That there is a much greater incongruity of Air to Glass, and some other
+Bodies, then there is of Water to the same_.
+
+By _Congruity, I mean a property of a fluid Body, whereby any part of it is
+readily united with any other part, either of itself, or of any other
+Similar, fluid, or solid body: And by Incongruity a property of a fluid, by
+which it is hindred from uniting with any dissimilar, fluid, or solid
+Body._
+
+This last property, any one that hath been observingly conversant about
+fluid Bodies, cannot be ignorant of. For (not now to mention several
+_Chymical Spirits_ and _Oyls_, which will _very hardly_, if at _all_, be
+brought to _mix_ with one another; insomuch that there may be found some 8
+or 9, or more, several distinct Liquors, which _swimming_ one upon another,
+will not presently _mix_) we need seek no further for Examples of this kind
+in _fluids_, then to observe the _drops of rain_ falling through the _air_
+and the _bubbles of air_ which are by any means conveyed under the surface
+of the _water_; or a drop of common _Sallet Oyl_ swimming upon water. In
+all which, and many more examples of this kind that might be enumerated,
+the _incongruity_ of two _fluids_ is easily discernable. And as for the
+_Congruity_ or _Incongruity_ of Liquids, with several kinds of _firm_
+Bodies, they have long since been taken notice of, and called by the Names
+of _Driness_ and _Moisture_ (though these two names are not comprehensive
+enough, being commonly used to signifie only the adhering or not adhering
+of _water_ to some other _solid Bodies_) of this kind we may observe that
+_water_ will more readily _wet some woods_ then _others_; and that _water_,
+let fall upon a _Feather_, the whiter side of a _Colwort_, and some other
+leaves, or upon almost any _dusty_, _unctuous_, or _resinous_ superficies,
+will not _at all adhere_ to them, but easily _tumble off_ from them, like a
+solid _Bowl_; whereas, if dropt upon _Linnen_, _Paper_, _Clay_, _green
+Wood_, &c. it will not be taken off, without leaving some part of it behind
+_adhering_ to them. So _Quick-silver_, which will very _hardly_ be brought
+to _stick_ to any _vegetable body_, will _readily adhere_ to, and _mingle_
+with, several clean _metalline bodies_.
+
+And that we may the better finde what the _cause_ of _Congruity_ and
+_Incongruity_ in bodies is, it will be requisite to consider, First, what
+is the _cause_ of _fluidness_; And this, _I conceive_, to be nothing else
+but a certain _pulse_ or _shake_ of _heat_; for Heat being nothing else but
+a very _brisk_ and _vehement agitation_ of the parts of a body (as I have
+elswhere made _probable_) the parts of a body are thereby made so _loose_
+from one another, that they easily _move any way_, and become _fluid_. That
+I may explain this a little by a gross Similitude, let us suppose a dish of
+sand set upon some body that is very much _agitated_, and shaken with some
+_quick_ and _strong vibrating motion_, as on a _Milstone_ turn'd round upon
+the under stone very violently whilst it is empty; or on a very stiff
+_Drum_-head, which is vehemently or very nimbly beaten with the Drumsticks.
+By this means, the sand in the dish, which before lay like a _dull_ and
+unactive body, becomes a perfect _fluid_; and ye can no sooner make a
+_hole_ in it with your finger, but it is immediately _filled up again_, and
+the upper surface of it _levell'd_. Nor can you _bury_ a _light body_, as a
+piece of Cork under it, but it presently _emerges_ or _swims_ as 'twere on
+the top; nor can you lay a _heavier_ on the top of it, as a piece of Lead,
+but it is immediately _buried_ in Sand, and (as 'twere) sinks to the
+bottom. Nor can you make a _hole_ in the side of the Dish, but the sand
+shall _run out_ of it to a _level_, not an _obvious property_ of a fluid
+body, as such, but this dos _imitate_; and all this meerly caused by the
+vehement _agitation_ of the conteining vessel; for by this means, _each_
+sand becomes to have a _vibrative_ or _dancing_ motion, so as no other
+heavier body can _rest_ on it, unless _sustein'd_ by some other on either
+side: Nor will it suffer any Body to be _beneath_ it, unless it be a
+_heavier_ then it self. Another Instance of the strange _loosening_ nature
+of a violent jarring Motion, or a strong and nimble vibrative one, we may
+have from a piece of _iron_ grated on very strongly with a _file_: for if
+into that a pin _screw'd_ so firm and hard, that though it has a convenient
+head to it, yet it can by no means be _unscrew'd_ by the fingers; if, I
+say, you attempt to unscrew this whilst _grated on by the file_, it will be
+found to undoe and turn very _easily_. The first of these Examples
+manifests, how a body actually _divided_ into small parts, becomes a
+_fluid_. And the latter manifests by what means the agitation of heat so
+easily _loosens_ and _unties_ the parts of _solid_ and _firm_ bodies. Nor
+need we suppose heat to be any thing else, besides such a motion; for
+supposing we could _Mechanically_ produce such a one _quick_ and _strong_
+enough, we need not spend _fuel_ to _melt_ a body. Now, that I do not speak
+this altogether groundless, I must refer the Reader to the Observations I
+have made upon the shining sparks of Steel, for there he shall find that
+_the same_ effects are produced upon small chips or parcels of Steel by the
+_flame_, and by _a quick and violent motion_; and if the body of _steel_
+may be thus melted (as I there shew it may) I think we have little reason
+to doubt that almost _any other_ may not also. Every Smith can inform one
+how quickly both his _File_ and the _Iron_ grows _hot_ with _filing_, and
+if you _rub_ almost any two _hard_ bodies together, they will do the same:
+And we know, that a sufficient degree of heat causes _fluidity_, in some
+bodies much sooner, and in others later; that is, the parts of the body of
+some are so _loose_ from one another, and so _unapt to cohere_, and so
+_minute_ and _little_, that a very _small_ degree of agitation keeps them
+always in the _state of fluidity_. Of this kind, I suppose, the _Æther_,
+that is the _medium_ or _fluid_ body, in which all other bodies do as it
+were swim and move; and particularly, the _Air_, which seems nothing else
+but a kind of _tincture_ or _solution_ of terrestrial and aqueous particles
+_dissolv'd_ into it, and agitated by it, just as the _tincture_ of
+_Cocheneel_ is nothing but some finer _dissoluble_ parts of that Concrete
+lick'd up or _dissolv'd_ by the _fluid_ water. And from this Notion of it,
+we may easily give a more Intelligible reason how the Air becomes so
+capable of _Rarefaction_ and _Condensation_. For, as in _tinctures_, one
+grain of some _strongly tinging_ substance may _sensibly_ colour some
+_hundred thousand_ grains of _appropriated_ Liquors, so as every _drop_ of
+it has its proportionate share, and be sensibly ting'd, as I have try'd
+both with _Logwood_ and _Cocheneel_: And as some few grains of _Salt_ is
+able to infect as great a quantity, as may be found by _præcipitations_,
+though not so easily by the _sight_ or _taste_; so the _Air_, which seems
+to be but as 'twere a _tincture_ or _saline substance, dissolv'd and
+agitated by the fluid and agil Æther_, may disperse and _expand_ it self
+into a _vast space_, if it have room enough, and infect, as it were, every
+part of that space. But, as on the other side, if there be but some _few
+grains_ of the liquor, it may _extract all_ the colour of the tinging
+substance, and may _dissolve_ all the Salt, and thereby become _much more
+impregnated_ with those substances, so may _all_ the air that sufficed in a
+_rarfy'd state_ to fill some _hundred thousand_ spaces of Æther, be
+compris'd in only _one_, but in a position proportionable _dense_. And
+though we have not yet found out such _strainers_ for Tinctures and Salts
+as we have for the Air, being yet unable to _separate_ them from their
+dissolving liquors by any kind of _filtre_, without _præcipitation_, as we
+are able to _separate_ the Air from the Æther by _Glass_, and several other
+bodies. And though we are yet unable and ignorant of the ways of
+_præcipitating_ Air out of the Æther as we can Tinctures, and Salts out of
+several _dissolvents_; yet neither of these seeming _impossible_ from the
+nature of the things, nor so _improbable_ but that some happy future
+industry may find out ways to effect them; nay, further, since we find that
+Nature _does really perform_ (though by what means we are not certain) both
+these actions, namely, by _præcipitating_ the Air in Rain and Dews, and by
+supplying the Streams and Rivers of the World with fresh water, _strain'd_
+through secret subterraneous Caverns: And since, that in very many other
+_proprieties_ they do so exactly _seem_ of the _same nature_; till further
+observations or tryals do inform us of the _contrary_, we may _safely
+enough conclude_ them of the _same kind_. For it seldom happens that any
+two natures have so many properties _coincident_ or the _same_, as I have
+observ'd Solutions and Air to have, and to be _different_ in the rest. And
+therefore I think it neither _impossible_, _irrational_, nay nor
+_difficult_ to be able to _predict_ what is _likely_ to happen in other
+particulars also, besides those which _Observation_ or _Experiment_ have
+declared thus or thus; especially, if the _circumstances_ that do often
+very much conduce to the variation of the effects be duly _weigh'd_ and
+_consider'd_. And indeed, were there not a _probability_ of this, our
+_inquiries_ would be _endless_, our _tryals vain_, and our greatest
+_inventions_ would be nothing but the meer _products_ of _chance_, and not
+of _Reason_; and, like _Mariners_ in an Ocean, destitute both of a
+_Compass_ and the sight of the _Celestial guids_, we might indeed, _by
+chance_, Steer _directly_ towards our desired Port, but 'tis _a thousand to
+one_ but we _miss_ our aim. But to proceed, we may hence also give a plain
+reason, how the Air comes to be _darkned_ by _clouds_, &c. which are
+nothing but a kind of _precipitation_, and how those _precipitations_ fall
+down in _Showrs_. Hence also could I very easily, and I think truly, deduce
+the cause of the curious _sixangular figures_ of Snow, and the appearances
+of _Haloes, &c._ and the sudden _thickning_ of the Sky with Clouds, and the
+_vanishing_ and _disappearing_ of those Clouds again; for all these things
+may be very easily _imitated_ in a _glass of liquor_, with some slight
+_Chymical preparations_ as I have often try'd, and may somewhere else more
+largely relate, but have not now time to set them down. But to proceed,
+there are other bodies that consist of particles more _Gross_, and of a
+more _apt_ figure for _cohesion_, and this requires _somewhat greater_
+agitation; such, I suppose [Mercury], _fermented vinous_ _Spirits_, several
+_Chymical Oils_, which are much of kin to those Spirits, &c. Others yet
+require a _greater_, as _water_, and so others _much greater_, for almost
+infinite degrees: For, I suppose there are very _few_ bodies in the world
+that may not be made _aliquatenus_ fluid, by _some_ or _other_ degree of
+agitation or heat.
+
+Having therefore in short set down my Notion of a Fluid body, I come in the
+next place to consider what _Congruity_ is; and this, as I said before,
+being a _Relative property_ of a fluid, whereby it may be said to be _like_
+or _unlike_ to this or that other body, whereby it _does_ or _does not mix_
+with this or that body. We will again have recourse to our former
+Experiment, though but a rude one; and here if we mix in the dish _several
+kinds_ of sands, some of _bigger_, others of _less_ and finer bulks, we
+shall find that by the agitation _the fine sand_ will _eject_ and _throw
+out_ of it self all those _bigger_ bulks of small _stones_ and the like,
+and those will _be gathered_ together all into _one_ place; and if there be
+_other_ bodies in it of other natures, those also will be _separated_ into
+a place by themselves, and _united_ or _tumbled_ up together. And though
+this do not come up to the _highest property_ of _Congruity_, which is a
+_Cohæsion_ of the parts of the fluid together, or a kind of _attraction_
+and _tenacity_, yet this does as 'twere _shadow_ it out, and somewhat
+resemble it; for just after the same manner, I suppose the _pulse_ of heat
+to _agitate_ the small parcels of matter, and those that are of a _like
+bigness_, and _figure_, and _matter_, will _hold_, or _dance_ together, and
+those which are of a _differing_ kind will be _thrust_ or _shov'd_ out from
+between them; for particles that are _similar_, will, like so many _equal
+musical strings equally stretcht_, vibrate together in a kind of _Harmony_
+or _unison_; whereas others that are _dissimilar_, upon what account
+soever, unless the disproportion be otherwise counter-ballanc'd, will, like
+so many _strings out of tune_ to those unisons, though they have the same
+agitating _pulse_, yet make quite _differing_ kinds of _vibrations_ and
+_repercussions_, so that though they may be both mov'd, yet are their
+_vibrations_ so _different_, and so _untun'd_, as 'twere to each other,
+that they _cross_ and _jar_ against each other, and consequently, _cannot
+agree_ together, but _fly back_ from each other to their similar particles.
+Now, to give you an instance how the _disproportion_ of some bodies in one
+respect, may be _counter-ballanc'd_ by a _contrary disproportion_ of the
+same body in another respect, whence we find that the subtil _vinous
+spirit_ is _congruous_, or does readily _mix_ with _water_, which in many
+properties is of a very _differing nature_, we may consider that a _unison_
+may be made either by two _strings_ of the same _bigness_, _length_, and
+_tension_, or by two strings of the same _bigness_, but of _differing
+length_, and a _contrary differing tension_, or _3ly._ by two strings of
+_unequal length_ and _bigness_, and of a _differing tension_, or of _equal
+length_, and _differing bigness_ and _tension_, and several other such
+varieties. To which _three properties_ in _strings_, will correspond _three
+proprieties_ also in _sand_, or the _particles_ of bodies, their _Matter_
+or _Substance_, their _Figure_ or _Shape_, and their _Body_ or _Bulk_. And
+from the _varieties_ of these _three_, may arise _infinite varieties_ in
+fluid bodies, though all agitated by the _same pulse_ or _vibrative_
+motion. And there may be as many ways of making Harmonies and Discords with
+these, as there may be with _musical strings_. Having therefore seen what
+is the cause of Congruity or Incongruity, those relative properties of
+fluids, we may, from what has been said, very easily collect, what is the
+_reason_ of those Relative proprieties also between _fluid bodies_ and
+_solid_; for since all bodies consist of _particles_ of such a _Substance_,
+_Figure_, and _Bulk_; but in some they are _united_ together more _firmly_
+then to be _loosened_ from each other by every _vibrative_ motion (though I
+imagine that there is no body in the world, but that some degree of
+agitation may, as I hinted before, agitate and loosen the particles so as
+to make them fluid) those _cohering_ particles may _vibrate_ in the same
+manner almost as those that are _loose_ and become _unisons_ or _discords_,
+as I may so speak, to them. Now that the _parts_ of all _bodies_, though
+never so _solid_, do yet _vibrate_, I think we need go no further for
+proof, then that _all_ bodies have some _degrees_ of _heat_ in them, and
+that there has not been yet found any thing _perfectly cold_: Nor can I
+believe indeed that there is any such thing in Nature, as a body whose
+particles are at _rest_, or _lazy_ and _unactive_ in the great _Theatre_ of
+the _World_, it being quite _contrary_ to the grand _Oeconomy_ of the
+Universe. We see therefore what is the reason of the _sympathy_ or uniting
+of some bodies together, and of the _antipathy_ or flight of others from
+each other: For _Congruity_ seems nothing else but a _Sympathy_, and
+_Incongruity_ an _Antipathy_ of bodies, hence _similar_ bodies once
+_united_ will not _easily part_, and _dissimilar_ bodies once _disjoyn'd_
+will not _easily unite_ again; from hence may be very easily deduc'd the
+reason of the _suspension_ of _water_ and _Quick-silver_ above their usual
+_station_, as I shall more at large anon shew.
+
+These properties therefore (alwayes the concomitants of fluid bodies)
+produce these following visible _Effects_:
+
+First, They _unite_ the parts of a fluid to its _similar_ Solid, or keep
+them _separate_ from its _dissimilar_. Hence _Quick-silver_ will (as we
+noted before) _stick_ to _Gold_, _Silver_, _Tin_, _Lead_, &c. and _unite_
+with them: but _roul_ off from _Wood_, _Stone_, _Glass_, &c. if never so
+little scituated out of its _horizontal level_; and _water_ that will _wet
+salt_ and _dissolve_ it, will _slip_ off from _Tallow_, or the like,
+without at all _adhering_; as it may likewise be observed to do upon a
+_dusty_ superficies. And next they cause the parts of _homogeneal fluid_
+bodies readily to _adhere_ together and _mix_, and of _heterogeneal_, to be
+exceeding _averse_ thereunto. Hence we find, that _two_ small _drops_ of
+_water_, on any superficies they can roul on, will, if they chance to touch
+each other, _readily unite_ and _mix_ into one 3d _drop_: The like may be
+observed with two small _Bowls_ of _Quick-silver_ upon a Table or Glass,
+provided their surfaces be not _dusty_; and with two drops of _Oyl_ upon
+fair water, _&c_. And further, _water_ put unto _wine_, _salt water_,
+_vinegar_, _spirit_ of _wine_, or the like, does immediately (especially if
+they be shaken together) _disperse_ it self all over them. Hence, on the
+contrary, we also find, that _Oyl of Tartar_ poured upon _Quick-silver,_
+and _Spirit of Wine_ on that _Oyl_, and _Oyl of Turpentine_ on that
+_Spirit_, and _Air_ upon that _Oyl_, though they be stopt closely up into a
+Bottle, and _shaken_ never so much, they will by no means long suffer any
+of their bigger parts to be _united_ or included within any of the other
+Liquors (by which recited Liquors, may be plainly enough represented the
+four _Peripatetical Elements_, and the more subtil _Æther_ above all.) From
+this property 'tis, that a drop of _water_ does not mingle with, or vanish
+into _Air_, but is _driven_ (by that Fluid equally protruding it on every
+side) and forc't into as little a space as it can possibly be contained in,
+namely, into a _Round Globule_. So likewise a little _Air_ blown under the
+_water_, is _united_ or thrust into a _Bubble_ by the ambient water. And a
+parcel of _Quick-silver_ enclosed with _Air_, _Water_, or almost any other
+_Liquor_, is _formed_ into a _round Ball_.
+
+Now the cause why all these included Fluids, newly mentioned, or as many
+others as are wholly included within a heterogeneous fluid, are not
+_exactly_ of a _Spherical Figure_ (seeing that if caused by these
+Principles only, it could be of no other) must proceed from some other kind
+of _pressure_ against the two opposite flatted sides. This _adventitious_
+or _accidental pressure_ may proceed from _divers causes_, and accordingly
+must _diversifie_ the Figure of the included heterogeneous fluid: For
+seeing that a body may be included either with a fluid only, or only with a
+solid, or partly with a fluid, and partly with a solid, or partly with one
+fluid, and partly with another; there will be found a very great variety of
+the terminating _surfaces_, much differing from a _Spherical_, according to
+the various resistance or pressure that belongs to each of these
+encompassing bodies.
+
+Which Properties may in general be deduced from two heads, _viz._ _Motion_,
+and _Rest_. For, either this Globular Figure is altered by a _natural
+Motion_, such as is _Gravity_, or a _violent_, such as is any _accidental
+motion_ of the fluids, as we see in the _wind_ ruffling up the water, and
+the _purlings_ of _Streams_, and _foaming_ of _Catarracts_, and the like.
+Or thirdly, By the _Rest_, _Firmness_ and _Stability_ of the ambient
+_Solid_. For if the including _Solid_ be of an _angular_ or any other
+_irregular_ Form, the included _fluid_ will be near of the _like_, as a
+Pint-_Pot_ full of _water_, or a _Bladder_ full of _Air_. And next, if the
+including or included fluid have a greater _gravity_ one than another, then
+will the _globular_ Form be deprest into an _Elliptico-spherical_: As if,
+for example, we suppose the Circle _ABCD_, in the _fourth Figure_, to
+represent a _drop of water_, _Quick-silver_, or the like, included with the
+_Air_ or the like, which supposing there were no _gravity_ at all in either
+of the _fluids_, or that the _contained_ and _containing_ were of the _same
+weight,_ would be _equally comprest_ into an exactly _spherical_ body (the
+ambient fluid _forcing equally_ against every side of it.) But supposing
+either a greater _gravity_ in the included, by reason whereof the parts of
+it being _prest_ from _A_ towards _B_, and thereby the whole put into
+_motion_, and that _motion_ being _hindred_ by the _resistance_ of the
+_subjacent_ parts of the ambient, the _globular_ Figure _ADBC_ will be
+_deprest_ into the _Elliptico-spherical_, _EGFH_. For the side _A_ is
+_detruded_ to _E_ by the _Gravity_, and _B_ to _F_ by the _resistance_ of
+the subjacent medium: and therefore _C_ must necessarily be thrust to _G_;
+and _D_ to _H_. Or else, supposing a greater _gravity_ in the _ambient_, by
+whose more then ordinary _pressure_ against the under side of the included
+globule; _B_ will be forced to _F_, and by its _resistance_ of the motion
+_upwards_, the side _A_ will be _deprest_ to _E_, and therefore _C_ being
+thrust to _G_ and _D_ to _H_; the _globular_ Figure by this means also will
+be made an _Elliptico-spherical_. Next if a fluid be included _partly_ with
+one, and _partly_ with another fluid, it will be found to be shaped
+_diversly_, according to the proportion of the _gravity_ and _incongruity_
+of the 3 _fluids_ one to another: As in the _second Figure_, let the upper
+_MMM_ be _Air_, the middle _LMNO_ be common _Oyl_, the lower _OOO_ be
+_Water_, the _Oyl_ will be form'd, not into a _spherical_ Figure, such as
+is represented by the _pricked Line_, but into such a Figure as LMNO, whose
+side LMN will be of a flatter _Elliptical_ Figure, by reason of the great
+disproportion between the _Gravity_ of _Oyl_ and _Air_, and the side LOM of
+a rounder, because of the smaller difference between the weight of _Oyl_
+and _Water_. Lastly, The _globular_ Figure will be changed, if the
+_ambient_ be partly _fluid_ and partly _solid_. And here the termination of
+the incompassed _fluid_ towards the incompassing is shap'd according to the
+proportion of the congruity or incongruity of the _fluids_ to the _solids_,
+and of the gravity and incongruity of the _fluids_ one to another. As
+suppose the subjacent _medium_ that hinders an included fluids descent, be
+a _solid_, as let KI, in the _fourth Figure_, represent the smooth
+superficies of a _Table_; EGFH, a parcel of _running Mercury_; the side GFH
+will be more flatted, according to the proportion of the incongruity of the
+_Mercury_ and _Air_ to the _Wood_, and of the _gravity_ of _Mercury_ and
+_Air_ one to another; The side GEH will likewise be a little more deprest
+by reason the subjacent parts are now at rest, which were before in motion.
+
+Or further in the _third figure_, let AILD represent an including _solid_
+medium of a cylindrical shape (as suppose a small _Glass Jar_) Let FGEMM
+represent a contain'd _fluid_, as water; this towards the bottom and sides,
+is figured according to the concavity of the _Glass_: But its upper
+_Surface_, (which by reason of its gravity, (not considering at all the Air
+above it, and so neither the congruity or incongruity of either of them to
+the Glass) should be terminated by part of a _Sphere_ whose diameter should
+be the same with that of the earth, which to our sense would appear a
+straight _Line_, as FGE, Or which by reason of its having a greater
+congruity to Glass than Air has, (not considering its Gravity) would be
+thrust into a _concave Sphere_, as CHB, whose diameter would be the same
+with that of the concavity of the Vessel:) Its upper Surface, I say, by
+reason of its having a greater gravity then the Air, and having likewise a
+greater congruity to Glass then the Air has, is terminated, by a _concave
+Elliptico-spherical Figure_, as CKB. For by its congruity it easily
+conforms it self, and adheres to the Glass, and constitutes as it were one
+containing body with it, and therefore should thrust the contained Air on
+that side it touches it, into a _spherical_ Figure, as BHC, but the motion
+of Gravity depressing a little the Corners B and C, reduces it into the
+aforesaid Figure CKB. Now that it is the greater congruity of one of the
+two _contiguous fluids_, then of the other, to the containing _solid_, that
+causes the separating surfaces to be thus or thus figured: And that it is
+not because this or that figurated surface is more proper, natural, or
+peculiar to one of these fluid bodies, then to the other, will appear from
+this; that the same _fluids_ will by being put into differing _solids_,
+change their _surfaces_. For the same water, which in a Glass or wooden
+Vessel will have a concave surface upwards, and will rise higher in a
+smaller then a greater Pipe, the same water, I say, in the same Pipes
+greased over or oyled, will produce quite contrary effects; for it will
+have a _protuberant_ and _convex_ surface upwards, and will not rise so
+high in small, as in bigger Pipes: Nay, in the very same solid Vessel, you
+may make the very same two contiguous _Liquids_ to alter their Surfaces;
+for taking a small Wine-glass, or such like Vessel, and pouring water
+gently into it, you shall perceive the _surface_ of the water all the way
+_concave_, till it rise even with the top, when you shall find it (if you
+gently and carefully pour in more) to grow very _protuberant_ and _convex_;
+the reason of which is plain, for that the _solid_ sides of the containing
+body are no longer extended, to which the water does more readily adhere
+then the air; but it is henceforth to be included with air, which would
+reduce it into a _hemisphere_, but by reason of its _gravity_, it is
+flatted into an _Oval_. _Quicksilver_ also which to _Glass_ is more
+incongruous then _Air_ (and thereby being put into a _Glass-pipe_, will not
+adhere to it, but by the more _congruous air_ will be forced to have a very
+_protuberant_ surface, and to rise higher in a greater then a lesser Pipe)
+this _Quicksilver_ to clean _Metal_, especially to _Gold_, _Silver_, _Tin_,
+_Lead_, &c. _Iron_ excepted, is more _congruous_ then _Air_, and will not
+only stick to it, but have a _concave_ Surface like _water_, and rise
+higher in a less, then in a greater Pipe.
+
+In all these Examples it is evident, that there is an _extraordinary_ and
+_adventitious force_, by which the _globular_ Figure of the contained
+_heterogeneous_ fluid is altered; neither can it be imagined, how it should
+otherwise be of any other Figure then _Globular_: For being by the
+_heterogeneous_ fluid equally _protruded_ every way, whatsoever part is
+_protuberant_, will be thereby _deprest_. From this cause it is, that in
+its effects it does very much resemble a _round Spring_ (such as a _Hoop_.)
+For as in a _round Spring_ there is required an additional _pressure_
+against two opposite sides, to reduce it into an _Oval_ Form, or to force
+it in between the sides of a _Hole,_ whose _Diameter_ is less then that of
+the _Spring_, there must be a considerable force or _protusion_ against
+_the concave_ or inner side of the _Spring_; So to alter this _spherical_
+constitution of an included fluid body, there is required more pressure
+against opposite sides to reduce it into an _Oval_; and, to press it into
+an _Hole_ less in _Diameter_ then it self, it requires a greater
+_protrusion_ against all the other sides, What degrees of force are
+requisite to reduce them into longer and longer _Ovals_, or to press them
+into less and less _holes_, I have not yet experimentally calculated; but
+thus much by experiment I find in general, that there is alwayes required a
+greater pressure to close them into longer _Ovals_, or protude them into
+smaller _holes_. The necessity and reason of this, were it requisite, I
+could easily explain: but being not so necessary, and requiring more room
+and time then I have for it at present, I shall here omit it; and proceed
+to shew, that this may be presently found true, if Experiment be made with
+a _round Spring_ (the way of making which trials is _obvious_ enough.) And
+with the fluid bodies of _Mercury_, _Air_, _&c_, the way of trying which,
+will be somewhat more difficult; and therefore I shall in brief describe
+it. He therefore that would try with _Air_, must first be provided of a
+_Glass-pipe_, made of the shape of that in the _fifth Figure_, whereof the
+side AB, represents a straight _Tube_ of about three foot long, C,
+represents another part of it, which consists of a _round Bubble_; so
+ordered, that there is left a _passage_ or _hole_ at the top, into which
+may be fastened with _cement_ several _small Pipes_ of determinate
+_cylindrical_ cavities: as let _hollow_ of
+
+  F.       1/4
+  G.       1/6
+  H.       1/8
+  I.  be   1/12   of an inch.
+  K.       1/16
+  L.       1/24
+  M.       1/32
+  &c----
+There may be added as many more, as the Experimenter shall think fit, with
+holes continually decreasing by known quantities, so far as his senses are
+able to help him; I say, so far, because there may be made _Pipes_ so small
+that it will be impossible to perceive the _perforation_ with ones naked
+eye, though by the help of a _Microscope_, it may easily enough be
+perceived: Nay, I have made a _Pipe_ perforated from end to end, so small,
+that with my naked eye I could very hardly see the body of it, insomuch
+that I have been able to knit it up into a knot without breaking: And more
+accurately examining one with my _Microscope_, I found it not so big as a
+sixteenth part of one of the smaller hairs of my head which was of the
+smaller and finer sort of hair, so that sixteen of these _Pipes_ bound
+faggot-wise together, would but have equalized one single hair; how small
+therefore must its _perforation_ be? It appearing to me through the
+_Microscope_ to be a proportionably _thick-sided Pipe_.
+
+To proceed then, for the trial of the Experiment, the Experimenter must
+place the _Tube_ AB, perpendicular, and fill the _Pipe_ F (cemented into
+the hole E) with water, but leave the _bubble_ C full of _Air_, and then
+gently pouring in water into the Pipe AB, he must observe diligently how
+high the water will rise in it before it protrude the _bubble_ of Air C,
+through the narrow passage of F, and denote exactly the height of the
+_Cylinder_ of water, then cementing in a second Pipe as G, and filling it
+with water; he may proceed as with the former, denoting likewise the height
+of the _Cylinder_ of water, able to protrude the _bubble_ C through the
+passage of G, the like may he do with the next _Pipe_, and the next, &c. as
+far as he is able: then comparing the several heights of the _Cylinders_,
+with the several _holes_ through which each _Cylinder_ did force the _air_
+(having due regard to the _Cylinders_ of water in the small _Tubes_) it
+will be very easie to determine, what force is requisite to press the _Air_
+into such and such _a hole_, or (to apply it to our present experiment) how
+much of the pressure of the _Air_ is taken off by its ingress into smaller
+and smaller _holes_. From the application of which to the entring of the
+_Air_ into the bigger _hole_ of the _Vessel_, and into the smaller _hole_
+of the _Pipe_, we shall clearly find, that there is a greater pressure of
+the air upon the water in the _Vessel_ or greater _pipe_, then there is
+upon that in the lesser _pipe_: For since the pressure of the _air_ every
+way is found to be equal, that is, as much as is able to press up and
+sustain a _Cylinder_ of _Quicksilver_ of two foot and a half high, or
+thereabouts; And since of this pressure so many more degrees are required
+to force the _Air_ into a smaller then into a greater _hole_ that is full
+of a more congruous fluid. And lastly, since those degrees that are
+requisite to press it in, are thereby taken off from the _Air_ within, and
+the _Air_ within left with so many degrees of pressure less then the _Air_
+without; it will follow, that the _Air_ in the less _Tube_ or _pipe_, will
+have less pressure against the superficies of the _water_ therein, then the
+_Air_ in the bigger: which was the minor Proposition to be proved.
+
+The Conclusion therefore will necessarily follow, _viz._ That _this unequal
+pressure of the Air caused by its ingress into unequal holes, is a cause
+sufficient to produce this effect, without the help of any other
+concurrent_; therefore is probably the principal (if not the only) cause of
+these _Phænomena_.
+
+This therefore being thus explained, there will be divers _Phænomena_
+explicable thereby, as, the rising of _Liquors_ in a _Filtre_, the rising
+of _Spirit of Wine_, _Oyl_, _melted Tallow_, &c. in the _Week_ of a _Lamp_,
+(though made of small _Wire_, _Threeds_ of _Asbestus_, _Strings_ of
+_Glass_, or the like) the rising of _Liquors_ in a _Spunge_, piece of
+_Bread_, _Sand_, &c. perhaps also the ascending of the _Sap_ in _Trees_ and
+_Plants_, through their small, and some of them _imperceptible pores_, (of
+which I have said more, on another occasion) at least the passing of it out
+of the earth into their roots. And indeed upon the consideration of this
+Principle, multitudes of other uses of it occurr'd to me, which I have not
+yet so well examined and digested as to propound for _Axioms_, but only as
+_Queries_ and _Conjectures_ which may serve as _hints_ toward some further
+_discoveries_.
+
+As first, Upon the consideration of the _congruity_ and _incongruity_ of
+Bodies, as to _touch_, I found also the like _congruity_ and _incongruity_
+(if I may so speak) as to the _Transmitting_ of the _Rates_ of Light: For
+as in this regard, _water_ (not now to mention other Liquors) seems nearer
+of affinity to _Glass_ then _Air_, and _Air_ then _Quicksilver_: whence an
+_oblique Ray_ out of _Glass_, will pass into _water_ with very little
+_refraction_ from the _perpendicular_, but none out of _Glass_ into _Air_,
+excepting a _direct_, will pass without a very great refraction from the
+perpendicular, nay any oblique Ray under thirty degrees, will not be
+admitted into the Air at all. And _Quicksilver_ will neither admit oblique
+or direct, but reflects all; seeming, as to the transmitting of the Raies
+of Light, to be of a quite differing constitution, from that of _Air_,
+_Water_, _Glass_, &c. and to resemble most those opacous and strong
+reflecting bodies of Metals: So also as to the property of cohesion or
+congruity, Water seems to keep the same order, being more congruous to
+Glass then Air, and Air then Quicksilver.
+
+A Second thing (which was hinted to me, by the consideration of the
+included fluids globular form, caused by the protrusion of the ambient
+heterogeneous fluid) was, whether the _Phænomena_ of gravity might not by
+this means be explained, by supposing the _Globe_ of Earth, Water, and Air
+to be included with a _fluid_, heterogeneous to all and each of them, so
+subtil, as not only to be every where _interspersed_ through the _Air_, (or
+rather the _air_ through it) but to _pervade_ the bodies of _Glass_, and
+even the _closest Metals_, by which means it may endeavour to _detrude_ all
+earthly bodies as far from it as it can; and partly thereby, and partly by
+other of its properties may move them towards the Center of the Earth. Now
+that there is some such fluid, I could produce many Experiments and
+Reasons, that do seem to prove it: But because it would ask some time and
+room to set them down and explain them, and to consider and answer all the
+Objections (many whereof I foresee) that may be alledged against it; I
+shall at present proceed to other _Queries_, contenting my self to have
+here only given a hint of what I may say more elswhere.
+
+A Third _Query_ then was, Whether the _heterogeneity_ of the _ambient
+fluid_ may not be accounted a _secondary cause_ of the _roundness_ or
+_globular form_ of the _greater bodies_ of the world, such as are those of
+the _Sun_, _Stars_, and _Planets_, the _substance_ of each of which seems
+altogether _heterogeneous_ to the _circum-ambient fluid æther_? And of this
+I shall say more in the Observation of the Moon.
+
+A Fourth was, Whether the _globular form_ of the _smaller parcels_ of
+matter here upon the _Earth_, as that of _Fruits_, _Pebbles_, or _Flints_,
+&c. (which seem to have been a _Liquor_ at first) may not be caused by the
+_heterogeneous ambient fluid_. For thus we see that melted _Glass_ will be
+naturally formed into a _round Figure_; so likewise any small Parcel of any
+_fusible body_, if it be perfectly enclosed by the _Air_, will be driven
+into a _globular_ Form; and, when cold, will be found a _solid Ball_. This
+is plainly enough manifested to us by their way of making _shot_ with the
+_drops of Lead_; which being a very pretty curiosity, and known but to a
+very few, and having the liberty of publishing it granted me, by that
+_Eminent Virtuoso_ Sir _Robert Moray_, who brought in this Account of it to
+the _Royal Society_, I have here transcribed and inserted.
+
+To make small shot of different sizes; Communicated by his Highness _P.R._
+
+_Take Lead out of the Pig what quantity you please, melt it down, stir and
+clear it with an iron Ladle, gathering together the blackish parts that
+swim at top like scum, and when you see the colour of the clear Lead to be
+greenish, but no sooner, strew upon it _Auripigmentum_ powdered according
+to the quantity of Lead, about as much as will lye upon a half Crown piece
+will serve for eighteen or twenty pound weight of some sorts of Lead;
+others will require more, or less. After the _Auripigmentum_ is put in,
+stir the Lead well, and the _Auripigmentum_ will flame: when the flame is
+over, take out some of the Lead in a Ladle having a lip or notch in the
+brim for convenient pouring out of the Lead, and being well warmed amongst
+the melted Lead, and with a stick make some single drops of Lead trickle
+out of the Ladle into water in a Glass, which if they fall to be round and
+without tails, there is _Auripigmentum_ enough put in, and the temper of
+the heat is right, otherwise put in more. Then lay two bars of Iron (or
+some more proper Iron-tool made on purpose) upon a Pail of water, and place
+upon them a round Plate of Copper, of the size and figure of an ordinary
+large Pewter or Silver Trencher, the hollow whereof is to be about three
+inches over, the bottom lower then the brims about half an inch, pierced
+with thirty, forty, or more small holes; the smaller the holes are, the
+smaller the shot will be; and the brim is to be thicker then the bottom, to
+conserve the heat the better._
+
+_The bottom of the Trencher being some four inches distant from the water
+in the Pail, lay upon it some burning Coles, to keep the Lead melted upon
+it. Then with the hot Ladle take Lead off the Pot where it stands melted,
+and pour it softly upon the burning Coles over the bottom of the Trencher,
+and it will immediately run through the holes into the water in small round
+drops. Thus pour on new Lead still as fast as it runs through the Trencher
+till all be done; blowing now and then the Coles with hand-Bellows, when
+the Lead in the Trencher cools so as to stop from running._
+
+_While one pours on the Lead, another must, with another Ladle, thrusted
+four or five inches under water in the Pail, catch from time to time some
+of the shot, as it drops down, to see the size of it, and whether there be
+any faults in it. The greatest care is to keep the Lead upon the Trencher
+in the right degree of heat; if it be too cool, it will not run through the
+Trencher, though it stand melted upon it; and this is to be helped by
+blowing the Coals a little, or pouring on new Lead that is hotter: but the
+cooler the Lead, the larger the Shot; and the hotter, the smaller; when it
+it too hot, the drops will crack and fly; then you must stop pouring on new
+Lead, and let it cool; and so long as you observe the right temper of the
+heat, the Lead will constantly drop into very round Shot, without so much
+as one with a tail in many pounds._
+
+_When all is done, take your Shot out of the Pail of water, and put it in a
+Frying-pan over the fire to dry them, which must be done warily, still
+shaking them that they melt not; and when they are dry you may separate the
+small from the great, in Pearl Sives made of Copper or Lattin let into one
+another, into as many sizes at you please. But if you would have your Shot
+larger then the Trencher makes them, you may do it with a Stick, making
+them trickle out of the Ladle, as hath been said._
+
+_If the Trencher be but toucht a very little when the Lead stops from going
+through it, and be not too cool, it will drop again, but it it better not
+to touch it at all. At the melting of the Lead take care that there be no
+kind of Oyl, Grease, or the like, upon the Pots, or Ladles, or Trencher._
+
+_The Chief cause of this Globular Figure of the Shot, seems to be the
+_Auripigmentum_; for, as soon as it is put in among the melted Lead, it
+loses its shining brightness, contracting instantly a grayish film or skin
+upon it, when you scum it to make it clean with the Ladle. So that when the
+Air comes at the falling drop of the melted Lead, that skin constricts them
+every where equally: but upon what account, and whether this be the true
+cause, is left to further disquisition._
+
+Much after this same manner, when the Air is exceeding cold through which
+it passes; do we find the drops of Rain, falling from the Clouds, congealed
+into round Hail-stones by the freezing Ambient.
+
+To which may be added this other known Experiment, That if you gently let
+fall a drop of _water_ upon small _sand_ or _dust_, you shall find, as it
+were, an artificial _round stone_ quickly generated. I cannot upon this
+occasion omit the mentioning of the strange kind of _Grain_, which I have
+observed in a _stone_ brought from _Kettering_ in _Northamptonshire_, and
+therefore called by Masons _Kettering-Stone_, of which see the Description.
+Which brings into my mind what I long since observed in the fiery Sparks
+that are struck out of a Steel. For having a great desire to see what was
+left behind, after the Spark was gone out, I purposely struck fire over a
+very white piece of Paper, and observing diligently where some conspicuous
+sparks went out, I found a very little black spot no bigger then the point
+of a Pin, which through a _Microscope_ appeared to be a perfectly round
+Ball, looking much like a polisht ball of Steel, insomuch that I was able
+to see the Image of the window reflected from it. I cannot here stay
+(having done it more fully in another place) to examine the particular
+Reasons of it, but shall only hint, that I imagine it to be some small
+parcel of the Steel, which by the violence of the motion of the stroke
+(most of which seems to be imprest upon those small parcels) is made so
+glowing hot, that it is melted into a _Vitrum_, which by the ambient Air is
+thrust into the form of a Ball.
+
+A Fifth thing which I thought worth Examination was, Whether the motion of
+all kind of Springs, might not be reduced to the Principle whereby the
+included _heterogeneous fluid_ seems to be moved; or to that whereby two
+Solids, as Marbles, or the like, are thrust and kept together by the
+_ambient fluid_.
+
+A Sixth thing was, Whether the Rising and Ebullition of the Water out of
+Springs and Fountains (which lie much higher from the Center of the Earth
+then the Superficies of the Sea, from whence it seems to be derived) may
+not be explicated by the rising of Water in a smaller Pipe: For the
+Sea-water being strained through the Pores or Crannies of the Earth, is, as
+it were, included in little Pipes, where the pressure of the Air has not so
+great a power to resist its rising: But examining this way, and finding in
+it several difficulties almost irremovable, I thought upon a way that would
+much more naturally and conceivably explain it, which was by this following
+Experiment: I took a Glass-Tube, of the form of that described in the sixth
+Figure, and chusing two _heterogeneous fluids_, such as Water and Oyl, I
+poured in as much Water as filled up the Pipes as high as AB, then putting
+in some Oyl into the Tube AC, I deprest the superficies A of the Water to
+F, and B I raised to G, which was not so high perpendicularly as the
+superficies of the Oyl F, by the space FI, wherefore the proportion of the
+gravity of these two Liquors was as GH to FE.
+
+This Experiment I tried with several other Liquors, and particularly with
+fresh Water and Salt (which I made by dissolving Salt in warm Water) which
+two though they are nothing heterogeneous, yet before they would perfectly
+mix one with another, I made trial of the Experiment: Nay, letting the Tube
+wherein I tried the Experiment remain for many dayes, I observed them not
+to mix; but the superficies of the fresh was rather more then less elevated
+above that of the Salt. Now the proportion of the gravity of Sea-water, to
+that of River-water, according to _Stevinus_ and _Varenius_, and as I have
+since found pretty true by making trial my self, is as 46. to 45. that is,
+46. Ounces of the salt Water will take up no more room then 45. of the
+fresh. Or reciprocally 45 pints of salt-water weigh as much as 46 of fresh.
+
+But I found the proportion of Brine to fresh Water to be near 13 to 12:
+Supposing therefore GHM to represent the Sea, and FI the height of the
+Mountain above the Superficies of the Sea, FM a Cavern in the Earth,
+beginning at the bottom of the Sea, and terminated at the top of the
+Mountain, LM the Sand at the bottom, through which the Water is as it were
+strained, so as that the fresher parts are only permitted to transude, and
+the saline kept back; if therefore the proportion of G M to FM be as 45 to
+46, then may the Cylinder of Salt-water GM make the Cylinder of Fresh-water
+to rise as high as E, and to run over at N. I cannot here stand to examine
+or confute their Opinion, who make the depth of the Sea, below its
+Superficies, to be no more perpendicularly measured then the height of the
+Mountains above it: 'Tis enough for me to say, there is no one of those
+that have asserted it, have experimentally known the perpendicular of
+either; nor shall I here determine, whether there may not be many other
+causes of the separation of the fresh water from the salt, as perhaps some
+parts of the Earth through which it is to pass, may contain a Salt, that
+mixing and uniting with the Sea-salt, may precipitate it; much after the
+same manner as the _Alkalizate_ and _Acid Salts_ mix and precipitate each
+other in the preparation of _Tartarum Vitriolatum._ I know not also whether
+the exceeding cold (that must necessarily be) at the bottom of the Water,
+may not help towards this separation, for we find, that warm Water is able
+to dissolve and contain more Salt, then the same cold; insomuch that Brines
+strongly impregnated by heat, if let cool, do suffer much of their Salt to
+subside and crystallize about the bottom and sides. I know not also whether
+the exceeding pressure of the parts of the Water one against another, may
+not keep the Salt from descending to the very bottom, as finding little or
+no room to insert it self between those parts, protruded so violently
+together, or else squeeze it upwads into the superiour parts of the Sea,
+where it may more easily obtain room for it self, amongst the parts of the
+Water, by reason that there is more heat and less pressure. To this Opinion
+I was somewhat the more induced by the relations I have met with in
+_Geographical Writers_, of drawing fresh Water from the bottom of the Sea,
+which is salt above. I cannot now stand to examine, whether this natural
+perpetual motion may not artificially be imitated: Nor can I stand to
+answer the Objections which may be made against this my Supposition: As,
+First, How it comes to pass, that there are sometimes salt Springs much
+higher then the Superficies of the Water? And, Secondly, Why Springs do not
+run faster and slower, according to the varying height made of the Cylinder
+of Sea-water, by the ebbing and flowing of the Sea?
+
+As to the First, In short, I say, the fresh Water may receive again a
+saline Tincture near the Superficies of the Earth, by passing through some
+salt _Mines_, or else many of the saline parts of the Sea may be kept back,
+though not all.
+
+And as to the Second, The same _Spring_ may be fed and supplyed by divers
+_Caverns_, coming from very far distant parts of the _Sea_, so as that it
+may in one place be _high_, in another _low water_; and so by that means
+the _Spring_ may be equally supply'd at all times. Or else the _Cavern_ may
+be so straight and narrow, that the water not having so ready and free
+passage through it, cannot upon so short and quick mutations of pressure,
+be able to produce any sensible effect at such a distance. Besides that, to
+confirm this _hypothesis_, there are many _Examples_ found in _Natural
+Historians_, of _Springs_ that do ebb and flow like the Sea: As
+particularly, those recorded by the Learned _Camden_, and after him by
+_Speed,_ to be found in this _Island_: One of which, they relate to be on
+the Top of a Mountain, by the small Village _Kilken_ in _Flintshire_,
+_Maris æmulus qui statis temporibus suos evomit & resorbet Aquas_; Which at
+certain times riseth and falleth after the manner of the Sea. A Second in
+_Caermardenshire,_ near _Caermarden_, at a place called _Cantred Bichan_;
+_Qui (ut scribit Giraldus) naturali die bis undis deficiens, & toties
+exuberans, marinas imitatur instabilitates_; That twice in four and twenty
+hours ebbing and flowing; resembleth the unstable motions of the Sea. The
+_Phænomena_ of which two may be easily made out, by supposing the _Cavern_,
+by which they are fed, to arise from the bottom of the next Sea. A Third,
+is a Well upon the River _Ogmore_ in _Glamorganshire_, and near unto
+_Newton_, of which _Camden_ relates himself to be certified, by a Letter
+from a Learned Friend of his that observed it, _Fons abest hinc, &c._ The
+Letter is a little too long to be inserted, but the substance is this; That
+this Well ebbs and flows quite contrary to the flowing and ebbing of the
+Sea in those parts: for 'tis almost empty at Full Sea, but full at Low
+water. This may happen from the Channel by which it is supplied, which may
+come from the bottom of a Sea very remote from those parts, and where the
+Tides are much differing from those of the approximate shores. A Fourth,
+lies in _Westmorland_, near the River _Leder_; _Qui instar Euripi sæpius in
+die reciprocantibus undis fluit & refluit_, which ebbs and flows many times
+a day. This may proceed from its being supplyed from many Channels, coming
+from several parts of the Sea, lying sufficiently distant asunder to have
+the times of High-water differing enough one from the other; so as that
+whensoever it shall be High water over any of those places, where these
+Channels begin, it shall likewise be so in the Well; but this is but a
+supposition.
+
+A Seventh _Query_ was, Whether the _dissolution_ or mixing of several
+bodies, whether fluid or solid, with saline or other Liquors, might not
+partly be attributed to this Principle of the congruity of those bodies and
+their dissolvents? As of Salt in Water, Metals in several _Menstruums_,
+Unctuous Gums in Oyls, the mixing of Wine and Water, &c. And whether
+_precipitation_ be not partly made from the same Principle of Incongruity?
+I say _partly_, because there are in some Dissolutions, some other Causes
+concurrent.
+
+I shall lastly make a much more seemingly strange and unlikely _Query_; and
+that is, Whether this Principle, well examined and explained, may not be
+found a _co-efficient_ in the most considerable Operations of Nature? As in
+those of _Heat_, and _Light_ consequently of _Rarefaction_ and
+_Condensation_, _Hardness_, and _Fluidness_, _Perspicuity_ and
+_Opacousness_, _Refractions_ and _Colours. &c._ Nay, I know not whether
+there may be many things done in Nature, in which this may not (be said to)
+have a Finger? This I have in some other passages of this Treatise further
+enquired into and shewn, that as well _Light_ as _Heat_ may be caused by
+_corrosion_, which is applicable to _congruity_, and consequently all the
+rest will be but _subsequents_: In the mean time I would not willingly be
+guilty of that _Error_, which the thrice Noble and Learned _Verulam_ justly
+takes notice of, as such, and calls _Philosophiæ Genus Empiricum, quod in
+paucorum Experimentorum Angustiis & Obscuritate fundatum est_. For I
+neither conclude from one single Experiment, nor are the Experiments I make
+use of all made upon one Subject: Nor wrest I any Experiment to make it
+_quadrare_ with any preconceiv'd Notion. But on the contrary, I endeavour
+to be conversant in divers kinds of Experiments, and all and every one of
+those Trials, I make the Standards or Touchstones, by which I try all my
+former Notions, whether they hold out in weight, and measure, and touch,
+&c. For as that Body is no other then a Counterfeit Gold, which wants any
+one of the Proprieties of Gold, (such as are the Malleableness, Weight,
+Colour, Fixtness in the Fire, Indissolubleness in _Aqua fortis_, and the
+like) though it has all the other; so will all those Notions be found to be
+false and deceitful, that will not undergo all the Trials and Tests made of
+them by Experiments. And therefore such as will not come up to the desired
+_Apex_ of Perfection, I rather wholly reject and take new, then by piecing
+and patching, endeavour to retain the old, as knowing such things at best
+to be but lame and imperfect. And this course I learned from Nature; whom
+we find neglectful of the old Body, and suffering its Decaies and
+Infirmities to remain without repair, and altogether sollicitous and
+careful of perpetuating the _Species_ by new _Individuals_. And it is
+certainly the most likely way to erect a glorious Structure and Temple to
+_Nature_, such as she will be found (by any _zealous Votary_) to reside in;
+to begin to build a new upon a sure Foundation of Experiments.
+
+But to digress no further from the consideration of the _Phænomena,_ more
+immediately explicable by this Experiment, we shall proceed to shew, That,
+as to the rising of Water in a _Filtre_, the reason of it will be manifest
+to him, that does take notice, that a _Filtre_ is constituted of a great
+number of small long solid bodies, which lie so close together, that the
+Air in its getting in between them, doth lose of its pressure that it has
+against the _Fluid_ without them, by which means the Water or Liquor not
+finding so strong a resistance between them as is able to counter-ballance
+the pressure on its superficies without, is raised upward, till it meet
+with a pressure of the Air which is able to hinder it. And as to the Rising
+of Oyl, melted Tallow, Spirit of Wine, &c. in the Week of a Candle or Lamp,
+it is evident, that it differs in nothing from the former, save only in
+this, that in a _Filtre_ the Liquor descends and runs away by another part;
+and in the Week the Liquor is dispersed and carried away by the Flame;
+something there is ascribable to the Heat, for that it may rarifie the more
+volatil and spirituous parts of those combustible Liquors, and so being
+made lighter then the Air, it maybe protruded upwards by that more
+ponderous fluid body in the Form of Vapours; but this can be ascribed to
+the ascension of but a very little, and most likely of that only which
+ascends without the Week. As for the Rising of it in a Spunge, Bread,
+Cotton, &c. above the superficies of the subjacent Liquor, what has been
+said about the _Filtre_ (if considered) will easily suggest a reason,
+considering that all these bodies abound with small holes or pores.
+
+From this same Principle also (_viz. the unequal pressure of the Air
+against the unequal superficies of the water_) proceeds the cause of the
+accession or incursion of any floating body against the sides of the
+containing Vessel; or the _appropinquation_ of two floating bodies, as
+_Bubbles_, _Corks_, _Sticks_, _Straws_, &c. one towards another. As for
+instance, Take a Glass-jar, such as AB in the seventh _Figure_, and filling
+it pretty near the top with water, throw into it a small round piece of
+Cork, as C, and plunge it all over in water, that it be wet, so as that the
+water may rise up by the sides of it, then placing it any where upon the
+superficies, about an inch, or one inch and a quarter from any side, and
+you shall perceive it by degrees to make _perpendicularly_ toward the
+nearest part of the side, and the nearer it approaches, the faster to be
+moved, the reason of which _Phænomenon_ will be found no other then this,
+that the Air has a greater pressure against the middle of the
+_superficies_, then it has against those parts that approach nearer, and
+are _contiguous_ to the sides. Now that the pressure is greater, may (as I
+shewed before in the explication of the third _Figure_) be evinced from the
+flatting of the water in the middle, which arises from the gravity of the
+under _fluid_: for since, as I shewed before, if there were no gravity in
+the under _fluid_, or that it were equal to that of the upper, the
+terminating Surface would be _Spherical_, and since it is the additional
+pressure of the gravity of water that makes it so flat, it follows, that
+the pressure upon the middle must be greater then towards the sides. Hence
+the Ball having a stronger pressure against that side of it which respects
+the middle of the _superficies_, then against that which respects the
+_approximate_ side, must necessarily move towards that part, from whence it
+finds least resistance, and so be _accelerated_, as the resistance
+decrease. Hence the more the water is raised under that part of its way it
+is passing above the middle, the faster it is moved: And therefore you will
+find it to move faster in E then in D, and in D then in C. Neither could I
+find the floating substance to be moved at all, until it were placed upon
+some part of the _Superficies_ that was sensibly elevated above the height
+of the middle part. Now that this may be the true cause, you may try with a
+blown Bladder, and an exactly round Ball upon a very smooth side of some
+pliable body, as _Horn_ or _Quicksilver._ For if the Ball be placed under a
+part of the Bladder which is upon one side of the middle of its pressure,
+and you press strongly against the Bladder, you shall find the Ball moved
+from the middle towards the sides.
+
+Having therefore shewn the reason of the motion of any float towards the
+sides, the reason of the incursion of any two floating bodies will easily
+appear: For the rising of the water against the sides of either of them, is
+an Argument sufficient, to shew the pressure of the Air to be there less,
+then it is further from it, where it is not so much elevated; and therefore
+the reason of the motion of the other toward it, will be the same as
+towards the side of the Glass, only here from the same reason, they are
+mutually moved toward each other, whereas the side of the Glass in the
+former remains fixt. If also you gently fill the Jar so full with water,
+that the water is _protuberant_ above the sides, the same piece of Cork
+that before did hasten towards the sides, does now fly from it as fast
+towards the middle of the Superficies; the reason of which will be found no
+other then this, that the pressure of the Air is stronger against the sides
+of the Superficies G and H, then against the middle I; for since, as I
+shewed before, the Principle of congruity would make the terminating
+Surface Spherical, and that the flatting of the Surface in the middle is
+from the abatement of the waters pressure outwards, by the contrary
+indeavour of its gravity; it follows that the pressure in the middle must
+be less then on the sides; and therefore the consecution will be the same
+as in the former. It is very odd to one that considers not the reason of
+it, to see two floating bodies of wood to approach each other, as though
+they were indued with some magnetical vigour; which brings into my mind
+what I formerly tried with a piece of Cork or such like body, which I so
+ordered, that by putting a little stick into the same water, one part of
+the said Cork would approach and make toward the stick, whereas another
+would discede and fly away, nay it would have a kind of verticity, so as
+that if the _Æquator_ (as I may so speak) of the Cork were placed towards
+the stick, if let alone, it would instantly turn its appropriate Pole
+toward it, and then run a-tilt at it: and this was done only by taking a
+dry Cork, and wetting one side of it with one small stroak; for by this
+means gently putting it upon the water, it would depress the superficies on
+every side of it that was dry, and therefore the greatest pressure of the
+Air, being near those sides, caused it either to chase away, or else to fly
+off from any other floating body, whereas that side only, against which the
+water ascended, was thereby able to attract.
+
+It remains only, that I should determine how high the Water or other Liquor
+may by this means be raised in a smaller Pipe above the Superficies of that
+without it, and at what height it may be sustained: But to determine this,
+will be exceeding difficult, unless I could certainly know how much of the
+Airs pressure is taken off by the smalness of such and such a Pipe, and
+whether it may be wholly taken off, that is, whether there can be a hole or
+pore so small, into which Air could not at all enter, though water might
+with its whole force, for were there such, 'tis manifest, that the water
+might rise in it to some five or six and thirty English Foot high. I know
+not whether the capillary Pipes in the bodies of small Trees, which we call
+their _Microscopical pores_, may not be such; and whether the congruity of
+the sides of the Pore may not yet draw the juyce even higher then the Air
+was able by its bare pressure to raise it: For, Congruity is a principle
+that not only unites and holds a body joyned to it, but, which is more,
+attracts and draws a body that is very near it, and holds it above its
+usual height.
+
+And this is obvious even in a drop of water suspended under any Similar or
+Congruous body: For, besides the ambient pressure that helps to keep it
+sustein'd, there is the Congruity of the bodies that are contiguous. This
+is yet more evident in Tenacious and Glutinous bodies; such as Gummous
+Liquors, Syrups, Pitch, and Rosin melted, &c. Tar, Turpentine, Balsom,
+Bird-lime, &c. for there it is evident, that the Parts of the tenacious
+body, as I may so call it, do stick and adhere so closely together, that
+though drawn out into long and very slender Cylinders, yet they will not
+easily relinquish one another; and this, though the bodies be _aliquatenus_
+fluid, and in motion by one another, which, to such as consider a fluid
+body only as its parts are in a confused irregular motion, without taking
+in also the congruity of the parts one among another, and incongruity to
+some other bodies, does appear not a little strange. So that besides the
+incongruity of the ambient fluid to it, we are to consider also the
+congruity of the parts of the contein'd fluid one with another.
+
+And this Congruity (that I may here a little further explain it) is both a
+Tenaceous and an Attractive power; for the Congruity, in the Vibrative
+motions, may be the cause of all kind of attraction, not only Electrical,
+but Magnetical also, and therefore it may be also of Tenacity and
+Glutinousness. For, from a perfect congruity of the motions of two distant
+bodies, the intermediate fluid particles are separated and droven away from
+between them, and thereby those congruous bodies are, by the incompassing
+mediums, compell'd and forced neerer together; wherefore that
+attractiveness must needs be stronger, when, by an immediate contact, they
+are forc'd to be exactly the same: As I shew more at large in my _Theory_
+of the _Magnet_. And this hints to me the reason of the suspension of the
+_Mercury_ many inches, nay many feet, above the usual station of 30 inches.
+For the parts of _Quick-Silver,_ being so very similar and congruous to
+each other, if once united, will not easily suffer a divulsion: And the
+parts of water, that were any wayes _heterogeneous_, being by _exantlation_
+or rarefaction exhausted, the remaining parts being also very similar, will
+not easily part neither. And the parts of the Glass being solid, are more
+difficultly disjoyn'd; and the water, being somewhat similar to both, is,
+as it were, a medium to unite both the _Glass_ and the _Mercury_ together.
+So that all three being united, and not very dissimilar, by means of this
+contact, if care be taken that the Tube in erecting be not shogged, the
+_Quicksilver_ will remain suspended, notwithstanding its contrary indeavour
+of Gravity, a great height above its ordinary Station; but if this
+immediate Contact be removed, either by a meer separation of them one from
+another by the force of a shog, whereby the other becomes imbodied between
+them, and licks up from the surface some agil parts, and so hurling them
+makes them air, or else by some small heterogeneous agil part of the Water,
+or Air, or Quicksilver, which appears like a bubble, and by its jumbling to
+and fro there is made way for the _heterogeneous Æther_ to obtrude it self
+between the Glass and either of the other Fluids, the Gravity of _Mercury
+precipitates_ it downward with very great violence; and if the Vessel that
+holds the restagnating _Mercury_ be convenient, the _Mercury_ will for a
+time _vibrate_ to and fro with very large _reciprocations_, and at last
+will remain kept up by the pressure of the external Air at the height of
+neer thirty inches. And whereas it may be objected, that it cannot be, that
+the meer imbodying of the _Æther_ between these bodies can be the cause,
+since the _Æther_ having a free passage alwayes, both through the Pores of
+the Glass, and through those of the Fluids, there is no reason why it
+should not make a separation at all times whilst it remains suspended, as
+when it is violently dis-joyned by a shog. To this I answer, That though
+the _Æther_ passes between the Particles, that is, through the Pores of
+bodies, so as that any chasme or separation being made, it has infinite
+passages to admit its entry into it, yet such is the tenacity or attractive
+virtue of Congruity, that till it be overcome by the meer strength of
+Gravity, or by a shog assisting that Conatus of Gravity, or by an agil
+Particle, that is like a leaver agitated by the _Æther_; and thereby the
+parts of the congruous substances are separated so far asunder, that the
+strength of congruity is so far weakened, as not to be able to reunite
+them, the parts to be taken hold of being removed out of the attractive
+Sphere, as I may so speak, of the congruity; such, I say, is the tenacity
+of congruity, that it retains and holds the almost contiguous Particles of
+the Fluid, and suffers them not to be separated, till by meer force that
+attractive or retentive faculty be overcome: But the separation being once
+made beyond the Sphere of the attractive activity of congruity, that virtue
+becomes of no effect at all, but the _Mercury_ freely falls downwards till
+it meet with a resistance from the pressure of the _ambient_ Air, able to
+resist its gravity, and keep it forced up in the Pipe to the height of
+about thirty inches.
+
+Thus have I gently raised a Steel _pendulum_ by a Loadstone to a great
+Angle, till by the shaking of my hand I have chanced to make a separation
+between them, which is no sooner made, but as if the Loadstone had retained
+no attractive virtue, the _Pendulum_ moves freely from it towards the other
+side. So vast a difference is there between the attractive virtue of the
+_Magnet_ when it acts upon a contiguous and upon a disjoyned body: and much
+more must there be between the attractive virtues of congruity upon a
+contiguous and disjoyned body; and in truth the attractive virtue is so
+little upon a body disjoyned, that though I have with a _Microscope_
+observed very diligently, whether there were any extraordinary
+_protuberance_ on the side of a drop of water that was exceeding neer to
+the end of a green stick, but did not touch it, I could not perceive the
+least; though I found, that as soon as ever it toucht it the whole drop
+would presently unite it self with it; so that it seems an absolute contact
+is requisite to the exercising of the tenacious faculty of congruity.
+
+       *       *       *       *       *
+
+
+Observ. VII. _Of some _Phænomena_ of Glass drops._
+
+These _Glass Drops_ are small parcels of coarse green Glass taken out of
+the Pots that contain the _Metal_ (as they call it) in fusion, upon the end
+of an Iron Pipe; and being exceeding hot, and thereby of a kind of sluggish
+fluid Confidence, are suffered to drop from thence into a Bucket of cold
+Water, and in it to lye till they be grown sensibly cold.
+
+Some of these I broke in the open air, by snapping off a little of the
+small stem with my fingers, others by crushing it with a small pair of
+Plyers; which I had no sooner done, then the whole bulk of the drop flew
+violently, with a very brisk noise, into multitudes of small pieces, some
+of which were as small as dust, though in some there were remaining pieces
+pretty large, without any flaw at all, and others very much flaw'd, which
+by rubbing between ones fingers was easily reduced to dust; these dispersed
+every way so violently, that some of them pierced my skin. I could not find
+either with my naked Eye, or a _Microscope_, that any of the broken pieces
+were of a regular figure, nor any one like another, but for the most part
+those that flaw'd off in large pieces were prettily branched.
+
+The ends of others of these drops I nipt off whilst all the bodies and ends
+of them lay buried under the water, which, like the former, flew all to
+pieces with as brisk a noise, and as strong a motion.
+
+Others of these I tried to break, by grinding away the blunt end, and
+though I took a seemingly good one, and had ground away neer two thirds of
+the Ball, yet would it not fly to pieces, but now and then some small rings
+of it would snap and fly off, not without a brisk noise and quick motion,
+leaving the Surface of the drop whence it flew very prettily branched or
+creased, which was easily discoverable by the _Microscope_. This drop,
+after I had thus ground it, without at all impairing the remnant that was
+not ground away, I caused to fly immediately all into sand upon the nipping
+off the very tip of its slender end.
+
+Another of these drops I began to grind away at the smaller end, but had
+not worn away on the stone above a quarter of an inch before the whole drop
+flew with a brisk crack into sand or small dust; nor would it have held so
+long, had there not been a little flaw in the piece that I ground away, as
+I afterwards found.
+
+Several others of these drops I covered over with a thin but very tuff skin
+of _Icthyocolla_, which being very tough and very transparent, was the most
+convenient substance for these tryals that I could imagine, having dipt, I
+say, several of these drops in this transparent Glue whilst hot, and
+suffering them to hang by a string tied about the end of them till they
+were cold, and the skin pretty tough; then wrapping all the body of the
+drop (leaving out only the very tip) in fine supple Kids-leather very
+closely, I nipped off the small top, and found, as I expected, that
+notwithstanding this skin of Glue, and the close wrapping up in Leather,
+upon the breaking of the top, the drop gave a crack like the rest, and gave
+my hand a pretty brisk impulse: but yet the skin and leather was so strong
+as to keep the parts from flying out of their former posture; and, the skin
+being transparent, I found that the drop retained exactly its former figure
+and polish, but was grown perfectly opacous and all over flaw'd, all those
+flaws lying in the manner of rings, from the bottom or blunt end, to the
+very top or small point. And by several examinations with a _Microscope_,
+of several thus broken, I found the flaws, both within the body of the
+drop, and on the outward surface, to lye much in this order.
+
+Let AB in the Figure X of the fourth Scheme represent the drop cased over
+with _Icthyocolla_ or _Isinglass_, (by being ordered as is before
+prescribed) crazed or flawed into pieces, but by the skin or case kept in
+its former figure, and each of its flawed parts preserved exactly in its
+due posture; the outward appearance of it somewhat plainly to the naked
+eye, but much more conspicuous if viewed with a small lens appeared much
+after this shape. That is, the blunt end B for a pretty breadth, namely, as
+far as the Ring CCC seemed irregularly flawed with divers clefts, which all
+seemed to tend towards the Center of it, being, as I afterwards found, and
+shall anon shew in the description of the figure Y, the Basis, as it were,
+of a Cone, which was terminated a little above the middle of the drop, all
+the rest of the Surface from CCC to A was flawed with an infinite number of
+small and parallel Rings, which as they were for the most part very round,
+so were they very thick and close together, but were not so exactly flaw'd
+as to make a perfect Ring, but each circular part was by irregular cracks
+flawed likewise into multitudes of irregular flakes or tiles; and this
+order was observed likewise the whole length of the neck.
+
+Now though I could not so exactly cut this _conical Body_ through the
+_Axis_, as is represented by the figure Y; yet by _anatomizing_, as it
+were, of several, and taking notice of divers particular circumstances, I
+was informed, that could I have artificially divided a flaw'd drop through
+the _Axis_ or _Center_, I should with a _Microscope_ have found it to
+appear much of this form, where A signifies the _Apex_, and B the blunt
+end, CC the Cone of the Basis, which is terminated at T the top or end of
+it, which seems to be the very middle of the blunt end in which, not only
+the conical body of the Basis CC is terminated, but as many of the parts of
+the drop as reach as high as DD.
+
+And it seemed to be the head or beginning of a Pith, as it were, or a part
+of the body which seemed more spungy then the rest, and much more
+irregularly flawed, which from T ascended by EE, though less visible, into
+the small neck towards A. The Grain, as it were, of all the flaws, that
+proceeds from all the outward Surface ADCCDA, was much the same, as is
+represented by the black strokes that meet in the middle DT, DT, DE, DE,
+&c.
+
+Nor is this kind of Grain, as I may call it, peculiar to Glass drops thus
+quenched; for (not to mention _Coperas-stones_, and divers other
+_Marchasites_ and _Minerals_, which I have often taken notice of to be in
+the very same manner flaked or grained, with a kind of Pith in the middle)
+I have observed the same in all manner of cast Iron, especially the coarser
+sort, such as Stoves, and Furnaces, and Backs, and Pots are made of: For
+upon the breaking of any of those Substances it is obvious to observe, how
+from the out-sides towards the middle, there is a kind of Radiation or
+Grain much resembling this of the Glass-drop; but this Grain is most
+conspicuous in Iron-bullets, if they be broken: the same _Phænomena_ may be
+produced by casting _regulus_ of _Antimony_ into a Bullet-mold, as also
+with _Glass of Antimony_, or with almost any such kind of _Vitrified
+substance_, either cast into a cold Mold or poured into Water.
+
+Others of these Drops I heat red hot in the fire, and then suffered them to
+cool by degrees. And these I found to have quite lost all their
+_fulminating_ or flying quality, as also their hard, brittle and springy
+texture; and to emerge of a much softer temper, and much easier to be
+broken or snapt with ones finger; but its strong and brittle quality was
+quite destroyed, and it seemed much of the same consistence with other
+green Glass well nealed in the Oven.
+
+The Figure and bigness of these for the most part was the same with that of
+the Figure Z; that is, all the surface of them was very smooth and polisht,
+and for the most part round, but very rugged or knobbed about D, and all
+the length of the stem was here and there pitted or flatted. About D, which
+is at the upper part of the drop under that side of the stem which is
+concave, there usually was made some one or more little Hillocks or
+Prominences. The drop it self, before it be broken, appears very
+transparent, and towards the middle of it, to be very full of small
+Bubbles, of some kind of aerial substance, which by the refraction of the
+outward surface appear much bigger then really they are, and this may be in
+good part removed, by putting the drop under the surface of clear Water,
+for by that means most part of the refraction of the convex Surface of the
+drop is destroyed, and the bubbles will appear much smaller. And this, by
+the by, minds me of the appearing magnitude of the _aperture_ of the
+_iris_, or _pupil_ of the eye, which though it appear, and be therefore
+judged very large, is yet not above a quarter of the bigness it appears of,
+by the _lenticular_ refraction of the _Cornea_.
+
+The cause of all which _Phænomena_ I imagine to be no other then this, That
+the Parts of the Glass being by the excessive heat of the fire kept off and
+separated one from another, and thereby put into a kind of sluggish fluid
+consistence, are suffered to drop off with that heat or agitation remaining
+in them, into cold Water; by which means the outsides of the drop are
+presently cool'd and _crusted_, and are thereby made of a loose texture,
+because the parts of it have not time to settle themselves leisurely
+together, and so to lie very close together: And the innermost parts of the
+drop, retaining still much of their former heat and agitations, remain of a
+loose texture also, and, according as the cold strikes inwards from the
+bottom and sides, are quenched, as it were, and made rigid in that very
+posture wherein the cold finds them. For the parts of the _crust_ being
+already hardened, will not suffer the parts to shrink any more from the
+outward Surface inward; and though it shrink a little by reason of the
+small parcels of some Aerial substances dispersed through the matter of the
+Glass, yet that is not neer so much as it appears (as I just now hinted;)
+nor if it were, would it be sufficient for to consolidate and condense the
+body of Glass into a _tuff_ and close _texture_, after it had been so
+excessively rarified by the heat of the glass-Furnace.
+
+But that there may be such an expansion of the aerial substance contained
+in those little _blebbs_ or bubbles in the body of the drop, this following
+Experiment will make more evident.
+
+       *       *       *       *       *
+
+Take a small Glass-Cane about a foot long, seal up one end of it
+_hermetically_, then put in a very small bubble of Glass, almost of the
+shape of an Essence-viol with the open mouth towards the sealed end, then
+draw out the other end of the Pipe very small, and fill the whole Cylinder
+with water, then set this Tube by the Fire till the Water begin to boyl,
+and the Air in the bubble be in good part rarified and driven out, then by
+sucking at the smalling Pipe, more of the Air or vapours in the bubble may
+be suck'd out, so that it may sink to the bottom; when it is sunk to the
+bottom, in the flame of a Candle, or Lamp, nip up the slender Pipe and let
+it cool: whereupon it is obvious to observe, first, that the Water by
+degrees will subside and shrink into much less room: Next, that the Air or
+vapours in the Glass will expand themselves so, as to buoy up the little
+Glass: Thirdly, that all about the inside of the Glass-pipe there will
+appear an infinite number of small bubbles, which as the Water grows colder
+and colder will swell bigger and bigger, and many of them buoy themselves
+up and break at the top.
+
+From this _Disceding_ of the heat in Glass drops, that is, by the quenching
+or cooling Irradiations propagated from the Surface upwards and inwards, by
+the lines CT, CT, DT, DE, &c. the bubbles in the drop have room to expand
+themselves a little, and the parts of the Glass contract themselves; but
+this operation being too quick for the sluggish parts of the Glass, the
+contraction is performed very unequally and irregularly, and thereby the
+Particles of the Glass are bent, some one way, and some another, yet so as
+that most of them draw towards the Pith or middle TEEE, or rather from that
+outward: so that they cannot _extricate_ or unbend themselves, till some
+part of TEEE be broken and loosened, for all the parts about that are
+placed in the manner of an Arch, and so till their hold at TEEE be loosened
+they cannot fly asunder, but uphold, and shelter, and fix each other much
+like the stones in a Vault, where each stone does concurre to the stability
+of the whole Fabrick, and no one stone can be taken away but the whole Arch
+falls. And wheresoever any of those radiating wedges DTD, &c. are removed,
+which are the component parts of this Arch, the whole Fabrick presently
+falls to pieces; for all the Springs of the several parts are set at
+liberty, which immediately extricate themselves and fly asunder every way;
+each part by its spring contributing to the darting of it self and some
+other contiguous part. But if this drop be heat so hot as that the parts by
+degrees can unbend themselves, and be settled and annealed in that posture,
+and be then suffered gently to subside and cool; The parts by this nealing
+losing their springiness, constitute a drop of a more soft but less brittle
+texture, and the parts being not at all under a flexure, though any part of
+the middle or Pith TEEE be broken, yet will not the drop at all fly to
+pieces as before.
+
+This Conjecture of mine I shall indeavour to make out by explaining each
+particular Assertion with _analogous_ Experiments: The Assertions are
+there.
+
+    First, That the parts of the Glass, whilst in a fluid Consistence and
+    hot, are more rarified, or take up more room, then when hard and cold.
+
+    Secondly, That the parts of the drop do suffer a twofold contraction.
+
+    Thirdly, That the dropping or quenching the glowing metal in the Water
+    makes it of a hard, springing, and rarified texture.
+
+    Fourthly, That there is a flexion or force remaining upon the parts of
+    the Glass thus quenched, from which they indeavour to extricate
+    themselves.
+
+    Fifthly, That the Fabrick of the drop, that is able to hinder the parts
+    from extricating themselves, is _analogus_ to that of an Arch.
+
+    Sixthly, That the sudden flying asunder of the parts proceeds from
+    their springiness.
+
+    Seventhly, That a gradual heating and cooling does anneal or reduce the
+    parts of Glass to a texture that is more loose, and easilier to be
+    broken, but not so brittle.
+
+That the first of these is true may be gathered from this, That _Heat is a
+property of a body arising from the motion or agitation of its parts_; and
+therefore whatever body is thereby toucht must necessarily receive some
+part of that motion, whereby its parts will be shaken and agitated, and so
+by degrees free and extricate themselves from one another, and each part so
+moved does by that motion _exert_ a _conatus_ of _protruding_ and
+displacing all the adjacent Particles. Thus Air included in a vessel, by
+being heated will burst it to pieces. Thus have I broke a Bladder held over
+the fire in my hand, with such a violence and noise, that it almost made me
+deaf for the present, and much surpassed the noise of a Musket: The like
+have I done by throwing into the fire small glass Bubbles hermetically
+sealed, with a little drop of Water included in them. Thus Water also, or
+any other Liquor, included in a convenient vessel, by being warmed,
+manifestly expands it self with a very great violence, so as to break the
+strongest vessel, if when heated it be narrowly imprisoned in it. This is
+very manifest by the _Sealed Thermometers_, which I have, by several
+tryals, at last brought to a great certainty and tenderness: for I have
+made some with stems above four foot long, in which the expanding Liquor
+would so far vary, as to be very neer the very top in the heat of Summer,
+and prety neer the bottom at the coldest time of the Winter. The Stems I
+use for them are very thick, straight, and even Pipes of Glass, with a very
+small _perforation_, and both the head and body I have made on purpose at
+the Glass-house, of the same metal whereof the Pipes are drawn: these I can
+easily in the flame of a Lamp, urged with the blast of a pair of Bellows,
+seal and close together, so as to remain very firm, close and even; by this
+means I joyn on the body first, and then fill both it and a part of the
+stem, proportionate to the length of the stem and the warmth of the season
+I fill it in with the best rectified _Spirit of Wine_ highly _ting'd_ with
+the lovely colour of _Cocheneel_, which I deepen the more by pouring some
+drops of common _Spirit of Urine_, which must not be too well rectified,
+because it will be apt to make the Liquor to curdle and stick in the small
+perforation of the stem. This Liquor I have upon tryal found the most
+tender of any spirituous Liquor, and those are much more sensibly affected
+with the variations of heat and cold then other more flegmatick and
+ponderous Liquors, and as capable of receiving a deep tincture, and keeping
+it, as any Liquor whatsoever; and (which makes it yet more acceptable) is
+not subject to be frozen by any cold yet known. When I have thus filled it,
+I can very easily in the forementioned flame of a Lamp seal and joyn on the
+head of it.
+
+Then, for graduating the stem, I fix that for the beginning of my division
+where the surface of the liquor in the stem remains when the ball is placed
+in common distilled water, that is so cold that it just begins to freeze
+and shoot into flakes; and that mark I fix at a convenient place of the
+stem, to make it capable of exhibiting very many degrees of cold, below
+that which is requisite to freeze water: the rest of my divisions, both
+above and below this (which I mark with a [0] or nought) I place according
+to the Degrees of _Expansion_, or _Contraction_ of the Liquor in proportion
+to the bulk it had when it indur'd the newly mention'd freezing cold. And
+this may be very easily and accurately enough done by this following way;
+Prepare a Cylindrical vessel of very thin plate Brass or Silver, ABCD of
+the figure Z; the Diameter AB of whose cavity let be about two inches, and
+the depth BC the same; let each end be cover'd with a flat and smooth plate
+of the same substance, closely soder'd on, and in the midst of the upper
+cover make a pretty large hole EF, about the bigness of a fifth part of the
+Diameter of the other; into this fasten very well with cement a straight
+and even Cylindrical pipe of Glass, EFGH, the Diameter of whose cavity let
+be exactly one tenth of the Diameter of the greater Cylinder. Let this pipe
+be mark'd at GH with a Diamant, so that G from E may be distant just two
+inches, or the same height with that of the cavity of the greater Cylinder,
+then divide the length EG exactly into 10 parts, so the capacity of the
+hollow of each of these divisions will be 1/1000 part of the capacity of
+the greater Cylinder. This vessel being thus prepared, the way of marking
+and graduating the _Thermometers_ may be very easily thus performed:
+
+Fill this Cylindrical vessel with the same liquor wherewith the
+_Thermometers_ are fill'd, then place both it and the _Thermometer_ you are
+to _graduate_, in water that is ready to be frozen, and bring the surface
+of the liquor in the _Thermometer_ to the first marke or [0]; then so
+proportion the liquor in the Cylindrical vessel, that the surface of it may
+just be at the lower end of the small glass-Cylinder; then very gently and
+gradually warm the water in which both the _Thermometer_ and this
+Cylindrical vessel stand, and as you perceive the ting'd liquor to rise in
+both stems, with the point of a Diamond give several marks on the stem of
+the _Thermometer_ at those places, which by comparing the expansion in both
+Stems, are found to correspond to the divisions of the cylindrical vessel,
+and having by this means marked some few of these divisions on the Stem, it
+will be very easie by these to mark all the rest of the Stem, and
+accordingly to assign to every division a proper character.
+
+A _Thermometer_, thus marked and prepared, will be the fittest Instrument
+to make a Standard of heat and cold that can be imagined. For being sealed
+up, it is not at all subject to variation or wasting, nor is it liable to
+be changed by the varying pressure of the Air, which all other kind of
+_Thermometers_ that are open to the Air are liable to. But to proceed.
+
+This property of Expansion with Heat, and Contraction with Cold, is not
+peculiar to Liquors only, but to all kind of solid Bodies also, especially
+Metals, which will more manifestly appear by this Experiment.
+
+Take the Barrel of a Stopcock of Brass, and let the Key, which is well
+fitted to it, be riveted into it, so that it may slip, and be easily turned
+round, then heat this Cock in the fire, and you will find the Key so
+swollen, that you will not be able to turn it round in the Barrel; but if
+it be suffered to cool again, as soon as it is cold it will be as movable,
+and as easie to be turned as before.
+
+This Quality is also very observable in _Lead_, _Tin_, _Silver_,
+_Antimony_, _Pitch_, _Rosin_, _Bees-wax_, _Butter_, and the like; all
+which, if after they be melted you suffer gently to cool, you shall find
+the parts of the upper Surface to subside and fall inwards, losing that
+plumpness and smoothness it had whilst in fusion. The like I have also
+observed in the cooling of _Glass of Antimony_, which does very neer
+approach the nature of Glass,
+
+But because these are all Examples taken from other materials then Glass,
+and argue only, that possibly there may be the like property also in Glass,
+not that really there is; we shall by three or four Experiments indeavour
+to manifest that also.
+
+And the First is an Observation that is very obvious even in these very
+drops, to wit, that they are all of them terminated with an unequal or
+irregular Surface, especially about the smaller part of the drop, and the
+whole length of the stem; as about D, and from thence to A, the whole
+Surface, which would have been round if the drop had cool'd leisurely, is,
+by being quenched hastily, very irregularly flatted and pitted; which I
+suppose proceeds partly from the Waters unequally cooling and pressing the
+parts of the drop, and partly from the self-contracting or subsiding
+quality of the substance of the Glass: For the vehemency of the heat of the
+drop causes such hidden motions and bubbles in the cold Water, that some
+parts of the Water bear more forcibly against one part then against
+another, and consequently do more suddenly cool those parts to which they
+are contiguous.
+
+A Second Argument may be drawn from the Experiment of cutting Glasses with
+a hot Iron. For in that Experiment the top of the Iron heats, and thereby
+rarifies the parts of the Glass that lie just before the crack, whence each
+of those agitated parts indeavouring to expand its self and get elbow-room,
+thrusts off all the rest of the contiguous parts, and consequently promotes
+the crack that was before begun.
+
+A Third Argument may be drawn from the way of producing a crack in a sound
+piece or plate of Glass, which is done two wayes, either First, by suddenly
+heating a piece of Glass in one place more then in another. And by this
+means _chymists_ usually cut off the necks of Glass-bodies, by two kinds of
+Instruments, either by a glowing hot round Iron-Ring, which just
+incompasses the place that is to be cut, or else by a _Sulphur'd_ Threed,
+which is often wound about the place where the separation is to be made,
+and then fired. Or Secondly, A Glass may be cracked by cooling it suddenly
+in any place with Water, or the like, after it has been all leisurely and
+gradually heated very hot. Both which _Phænomena_ seem manifestly to
+proceed from the _expansion_ and contraction of the parts of the Glass,
+which is also made more probable by this circumstance which I have
+observed, that a piece of common window-glass being heated in the middle
+very suddenly with a live Coal or hot Iron, does usually at the first crack
+fall into pieces, whereas if the Plate has been gradually heated very hot,
+and a drop of cold Water and the like be put on the middle of it, it only
+flaws it, but does not break it asunder immediately.
+
+A Fourth Argument may be drawn from this Experiment; Take a Glass-pipe, and
+fit into a solid stick of Glass, so as it will but just be moved in it.
+Then by degrees heat them whilst they are one within another, and they will
+grow stiffer, but when they are again cold, they will be as easie to be
+turned as before. This Expansion of Glass is more manifest in this
+Experiment.
+
+Take a stick of Glass of a considerable length, and fit it so between the
+two ends or screws of a Lath, that it may but just easily turn, and that
+the very ends of it may be just toucht and susteined thereby; then applying
+the flame of the Candle to the middle of it, and heating it hot, you will
+presently find the Glass to stick very fast on those points, and not
+without much difficulty to be convertible on them, before that by removing
+the flame for a while from it, it be suffered to cool, and when you will
+find it as easie to be turned round as at the first.
+
+From all which Experiments it is very evident, that all those Bodies, and
+particularly Glass, suffers an Expansion by Heat, and that a very
+considerable one, whilst they are in a state of Fusion. For _Fluidity_, as
+I elsewhere mention, _being nothing but an effect of very strong and quick
+shaking motion, whereby the parts are, as it were, loosened from each
+other, and consequently leave an interjacent space or vacuity_; it follows,
+that all those shaken Particles must necessarily take up much more room
+then when they were at rest, and lay quietly upon each other. And this is
+further confirmed by a Pot of _boyling Alabaster_, which will manifestly
+rise a sixth or eighth part higher in the Pot, whilst it is boyling, then
+it will remain at, both before and after it be boyled. The reason of which
+odd _Phænomenon_ (to hint it here only by the way) is this, that there is
+in the curious powder of Alabaster, and other calcining Stones, a certain
+watery substance, which is so fixt and included with the solid Particles,
+that till the heat be very considerable they will not fly away; but after
+the heat is increased to such a degree, they break out every way in
+vapours, and thereby so shake and loosen the small corpusles of the Powder
+from each other, that they become perfectly of the nature of a fluid body,
+and one may move a stick to and fro through it, and stir it as easily as
+water, and the vapours burst and break out in bubbles just as in boyling
+water, and the like; whereas, both before those watery parts are flying
+away, and after they are quite gone; that is, before and after it have done
+boyling, all those effects cease, and a stick is as difficultly moved to
+and fro in it as in sand, or the like. Which Explication I could easily
+prove, had I time; but this is not a fit place for it.
+
+To proceed therefore, I say, that the dropping of this expanded Body into
+cold Water, does make the parts of the Glass suffer a double contraction:
+The first is, of those parts which are neer the Surface of the Drop. For
+Cold, as I said before, contracting Bodies, that is, _by the abatement of
+the agitating faculty the parts falling neerer together_; the parts next
+adjoyning to the Water must needs lose much of their motion, and impart it
+to the Ambient-water (which the Ebullition and commotion of it manifests)
+and thereby become a solid and hard crust, whilst the innermost parts
+remain yet fluid and expanded; whence, as they grow cold also by degrees,
+their parts must necessarily be left at liberty to be condensed, but
+because of the hardness of the outward crust, the contraction cannot be
+admitted that way; but there being many very small, and before
+inconspicuous, bubbles in the substance of the Glass, upon the subsiding of
+the parts of the Glass, the agil substance contained in them has liberty of
+expanding it self a little, and thereby those bubbles grow much bigger,
+which is the second Contraction. And both these are confirmed from the
+appearance of the Drop it self: for as for the outward parts, we see,
+first, that it is irregular and shrunk, as it were, which is caused by the
+yielding a little of the hardened Skin to a Contraction, after the very
+outmost Surface is settled; and as for the internal parts, one may with
+ones naked Eye perceive abundance of very conspicuous bubbles, and with the
+_Microscope_ many more.
+
+The Consideration of which Particulars will easily make the Third Position
+probable, that is, that the parts of the drop will be of a very hard,
+though of a rarified Texture; for if the outward parts of the Drop, by
+reason of its hard crust, will indure very little Contraction, and the agil
+Particles, included in those bubbles, by the losing of their agitation, by
+the decrease of the Heat, lose also most part of their Spring and Expansive
+power; it follows (the withdrawing of the heat being very sudden) that the
+parts must be left in a very loose Texture, and by reason of the
+implication of the parts one about another, which from their sluggishnes
+and glutinousness I suppose to be much after the manner of the sticks in a
+Thorn-bush, or a Lock of Wool; it will follow, I say, that the parts will
+hold each other very strongly together, and indeavour to draw each other
+neerer together, and consequently their Texture must be very hard and
+stiff, but very much rarified.
+
+And this will make probable my next Position, That _the parts of the Glass
+are under a kind of tension or flexure, out of which they indeavour to
+extricate and free themselves_, and thereby all the parts draw towards the
+Center or middle, and would, if the outward parts would give way, as they
+do when the outward parts cool leisurely (as in baking of Glasses) contract
+the bulk of the drop into a much less compass. For since, as I proved
+before, the Internal parts of the drop, when fluid, were of a very rarified
+Texture, and, as it were, tos'd open like a Lock of Wool, and if they were
+suffered leisurely to cool, would be again prest, as it were, close
+together: And since that the heat, which kept them bended and open, is
+removed, and yet the parts not suffered to get as neer together as they
+naturally would; It follows, that the Particles remain under a kind of
+_tension_ and _flexure_, and consequently have an indeavour to free
+themselves from that _bending_ and _distension_, which they do, as soon as
+either the tip be broken, or as soon as by a leisurely heating and cooling,
+the parts are nealed into another posture.
+
+And this will make my next Position probable, that _the parts of the Glass
+drops are contignated together in the form of an Arch_, cannot any where
+yield or be drawn inwards, till by the removing of some one part of it (as
+it happens in the removing one of the stones of an Arch) the whole Fabrick
+is shatter'd, and falls to pieces, and each of the Springs is left at
+liberty, suddenly to extricate it self: for since I have made it probable,
+that the internal parts of the Glass have a contractive power inwards, and
+the external parts are incapable of such a Contraction, and the figure of
+it being spherical; it follows, that the superficial parts must bear
+against each other, and keep one another from being condens'd into a less
+room, in the same manner as the stones of an Arch conduce to the upholding
+each other in that Figure. And this is made more probable by another
+Experiment which was communicated to me by an excellent Person, whose
+extraordinary Abilities in all kind of Knowledg, especially in that of
+Natural things, and his generous Disposition in communicating, incouraged
+me to have recourse to him on many occasions. The Experiment was this:
+Small Glass-balls (about the bigness of that represented in the _Figure
+&._) would, upon rubbing or scratching the inward Surface, fly all
+insunder, with a pretty brisk noise; whereas neither before nor after the
+inner Surface had been thus scratcht, did there appear any flaw or crack.
+And putting the pieces of one of those broken ones together again, the
+flaws appeared much after the manner of the black lines on the Figure, _&._
+These Balls were small, but exceeding thick bubbles of Glass, which being
+crack'd off from the _Puntilion_ whilst very hot, and so suffered to cool
+without nealing them in the Oven over the Furnace, do thereby (being made
+of white Glass, which cools much quicker then green Glass, and is thereby
+made much brittler) acquire a very _porous_ and very brittle _texture_: so
+that if with the point of a Needle or Bodkin, the inside of any of them be
+rubbed prety hard, and then laid on a Table, it will, within a very little
+while, break into many pieces with a brisk noise, and throw the parts above
+a span asunder on the Table: Now though the pieces are not so small as
+those of a _fulminating_ drop, yet they as plainly shew, that the outward
+parts of the Glass have a great _Conatus_ to fly asunder, were they not
+held together by the _tenacity_ of the parts of the inward Surface: for we
+see as soon as those parts are crazed by hard rubbing, and thereby their
+tenacity spoiled, the springiness of the more outward parts quickly makes a
+divulsion, and the broken pieces will, if the concave Surface of them be
+further scratcht with a Diamond, fly again into smaller pieces.
+
+From which preceding considerations it will follow Sixthly, That the sudden
+flying asunder of the parts as soon as this Arch is any where disordered or
+broken, proceeds from the springing of the parts; which, indeavouring to
+_extricate_ themselves as soon as they get the liberty, they perform it
+with such a quickness, that they throw one another away with very great
+violence: for the Particles that compose the Crust have a _Conatus_ to lye
+further from one another, and therefore as soon as the external parts are
+loosened they dart themselves outward with great violence, just as so many
+Springs would do, if they were detained and fastened to the body, as soon
+as they should be suddenly loosened; and the internal parts drawing inward,
+they contract so violently; that they rebound back again and fly into
+multitude of small shivers or sands. Now though they appear not, either to
+the naked Eye, or the _Microscope_, yet I am very apt to think there may be
+abundance of small flaws or cracks, which, by reason the strong reflecting
+Air is not got between the _contiguous_ parts, appear not. And that this
+may be so, I argue from this, that I have very often been able to make a
+crack or flaw, in some convenient pieces of Glass, to appear and disappear
+at pleasure, according as by pressing together, or pulling asunder the
+contiguous parts, I excluded or admitted the strong reflecting Air between
+the parts: And it is very probable, that there may be some Body, that is
+either very rarified Air, or something _analogous_ to it, which fills the
+bubbles of these drops; which I argue, first, from the roundness of them,
+and next, from the vivid reflection of Light which they exhibite: Now
+though I doubt not, but that the Air in them is very much rarified, yet
+that there is some in them, to such as well consider this Experiment of the
+disappearing of a crack upon the _extruding_ of the Air, I suppose it will
+seem more then probable.
+
+The Seventh and last therefore that I shall prove, is, _That the gradual
+heating and cooling of these so extended bodies does reduce the parts of
+the Glass to a looser and softer temper_. And this I found by heating them,
+and keeping them for a prety while very red hot in a fire; for thereby I
+found them to grow a little lighter, and the small Stems to be very easily
+broken and snapt any where, without at all making the drop fly; whereas
+before they were so exceeding hard, that they could not be broken without
+much difficulty; and upon their breaking the whole drop would fly in pieces
+with very great violence. The Reason of which last seems to be, that the
+leisurely heating and cooling of the parts does not only wast some part of
+the Glass it self, but ranges all the parts into a better order, and gives
+each Particle an opportunity of _relaxing_ its self, and consequently
+neither will the parts hold so strongly together as before, nor be so
+difficult to be broken: The parts now more easily yielding, nor will the
+other parts fly in pieces, because the parts have no bended Springs. The
+_relaxation_ also in the temper of hardned Steel, and hammered Metals, by
+nealing them in the fire, seems to proceed from much the same cause. For
+both by quenching suddenly such Metals as have _vitrifed_ parts
+interspers'd, as Steel has, and by hammering of other kinds that do not so
+much abound with them, as Silver Brass, &c. the parts are put into and
+detained in a bended posture, which by the agitation of Heat are shaken,
+and loosened, and suffered to unbend themselves.
+
+       *       *       *       *       *
+
+
+Observ. VIII. _Of the fiery Sparks struck from a Flint or Steel._
+
+It is a very common Experiment, by striking with a Flint against a Steel,
+to make certain fiery and shining Sparks to fly out from between those two
+compressing Bodies. About eight years since, upon casually reading the
+Explication of this odd _Phænomenon_, by the most Ingenious _Des Cartes_, I
+had a great desire to be satisfied, what that Substance was that gave such
+a shining and bright Light: And to that end I spread a sheet of white
+Paper, and on it, observing the place where several of these Sparks seemed
+to vanish, I found certain very small, black, but glittering Spots of a
+movable Substance, each of which examining with my _Microscope_, I found to
+be a small round _Globule_; some of which, as they looked prety small, so
+did they from their Surface yield a very bright and strong reflection on
+that side which was next the Light; and each look'd almost like a prety
+bright Iron-Ball, whose Surface was prety regular, such as is represented
+by the Figure A. In this I could perceive the Image of the Window prety
+well, or of a Stick, which I moved up and down between the Light and it.
+Others I found, which were, as to the bulk of the Ball, prety regularly
+round, but the Surface of them, as it was not very smooth, but rough, and
+more irregular, so was the reflection from it more faint and confused. Such
+were the Surfaces of B. C. D. and E. Some of these I found cleft or
+cracked, as C, others quite broken in two and hollow, as D. which seemed to
+be half the hollow shell of a Granado, broken irregularly in pieces.
+Several others I found of other shapes; but that which is represented by E,
+I observed to be a very big Spark of fire, which went out upon one side of
+the Flint that I struck fire withall, to which it stuck by the root F, at
+the end of which small Stem was fastened-on a _Hemisphere_, or half a
+hollow Ball, with the mouth of it open from the stemwards, so that it
+looked much like a Funnel, or an old fashioned Bowl without a foot. This
+night, making many tryals and observations of this Experiment, I met, among
+a multitude of the Globular ones which I had observed, a couple of
+Instances, which are very remarkable to the confirmation of my
+_Hypothesis_.
+
+And the First was of a pretty big Ball fastened on to the end of a small
+sliver of Iron, which _Compositum_ seemed to be nothing else but a long
+thin chip of Iron, one of whose ends was melted into a small round Globul;
+the other end remaining unmelted and irregular, and perfectly Iron.
+
+The Second Instance was not less remarkable then the First; for I found,
+when a Spark went out, nothing but a very small thin long sliver of Iron or
+Steel, unmelted at either end. So that it seems, that some of these Sparks
+are the slivers or chips of the Iron _vitrified_, Others are only the
+slivers melted into Balls without vitrification, And the third kind are
+only small slivers of the Iron, made red-hot with the violence of the
+stroke given on the Steel by the Flint.
+
+He that shall diligently examine the _Phænomena_ of this Experiment, will,
+I doubt not, find cause to believe, that the reason I have heretofore given
+of it, is the true and genuine cause of it, namely, That _the Spark,
+appearing so bright in the falling, is nothing else but a small piece of
+the Steel or Flint, but most commonly of the Steel, which by the violence
+of the stroke is at the same time sever'd and heat red-hot, and that
+sometimes to such a degree, as to make it melt together into a small
+Globule of Steel; and sometimes also is that heat so very intense, as
+further to melt it and vitrifie it; but many times the heat is so gentle,
+as to be able to make the sliver only red hot, which notwithstanding
+falling upon the tinder_ (that is only a very curious small Coal made of
+the small threads of Linnen burnt to coals and char'd) _it easily sets it
+on fire_. Nor will any part of this _Hypothesis_ seem strange to him that
+considers, First, that either hammering, or filing or otherwise violently
+rubbing of Steel, will presently make it so hot as to be able to burn ones
+fingers. Next, that the whole force of the stroke is exerted upon that
+small part where the Flint and Steel first touch: For the Bodies being each
+of them so very hard, the puls cannot be far communicated, that is, the
+parts of each can yield but very little, and therefore the violence of the
+concussion will be _exerted_ on that piece of Steel which is cut off by the
+Flint. Thirdly, that the filings or small parts of Steel are very apt, as
+it were, to take fire, and are presently red hot, that is, there seems to
+be a very _combustible sulphureous_ Body in Iron or Steel, which the Air
+very readily preys upon, as soon as the body is a little violently heated.
+
+And this is obvious in the filings of Steel or Iron cast through the flame
+of a Candle; for even by that sudden _transitus_ of the small chips of
+Iron, they are heat red hot, and that _combustible sulphureous_ Body is
+presently prey'd upon and devoured by the _aereal_ incompassing
+_Menstruum_, whose office in this Particular I have shewn in the
+Explication of Charcole.
+
+And in prosecution of this Experiment, having taken the filings of Iron and
+Steel, and with the point of a Knife cast them through the flame of a
+Candle, I observed where some conspicuous shining Particles fell, and
+looking on them with my _Microscope_, I found them to be nothing else but
+such round Globules, as I formerly found the Sparks struck from the Steel
+by a stroke to be, only a little bigger; and shaking together all the
+filings that had fallen upon the sheet of Paper underneath and observing
+them with the _Microscope_, I found a great number of small Globules, such
+as the former, though there were also many of the parts that had remained
+untoucht and rough filings or chips of Iron. So that, it seems, Iron does
+contain a very _combustible sulphureous_ Body, which is, in all likelihood,
+one of the causes of this _Phænomenon_, and which may be perhaps very much
+concerned in the business of its hardening and tempering: of which somewhat
+it said in the Description of _Muscovy-glass_.
+
+So that, these things considered, we need not trouble our selves to find
+out what kind of Pores they are, both in the Flint and Steel, that contain
+the _Atoms of fire_, nor how those _Atoms_ come to be hindred from running
+all out, when a dore or passage in their Pores is made by the concussion:
+nor need we trouble our selves to examine by what _Prometheus_ the Element
+of Fire comes to be fetcht down from above the Regions of the Air, in what
+Cells or Boxes it is kept, and what _Epimetheus_ lets it go: Nor to
+consider what it is that causes so great a conflux of the atomical
+Particles of Fire, which are said to fly to a flaming Body, like Vultures
+or Eagles to a putrifying Carcass, and there to make a very great pudder.
+Since we have nothing more difficult in this _Hypothesis_ to conceive,
+first, as to the kindling of Tinder, then how a large Iron-bullet, let fall
+red or glowing hot upon a heap of Small-coal, should set fire to those that
+are next to it first: Nor secondly, is this last more difficult to be
+explicated, then that a Body, as Silver for Instance, put into a weak
+_Menstruum_, as unrectified _Aqua fortis_ should, when it is put in a great
+heat, be there dissolved by it, and not before; which _Hypothesis_ is more
+largely explicated in the Description of Charcoal. To conclude, we see by
+this Instance, how much Experiments may conduce to the regulating of
+_Philosophical notions_. For if the most Acute _Des Cartes_ had applied
+himself experimentally to have examined what substance it was that caused
+that shining of the falling Sparks struck from a Flint and a Steel, he
+would certainly have a little altered his _Hypothesis_, and we should have
+found, that his Ingenious Principles would have admitted a very plausible
+Explication of this _Phænomenon_; whereas by not examining so far as he
+might, he has set down an Explication which Experiment do's contradict.
+
+But before I leave this Description, I must not forget to take notice of
+the Globular form into which each of these is most curiously formed. And
+this _Phænomenon_, as I have elsewhere more largely shewn, proceeds from a
+propriety which belongs to all kinds of fluid Bodies more or less, and is
+caused by the Incongruity of the Ambient and included Fluid, which so acts
+and modulates each other, that they acquire, as neer as is possible, a
+_spherical_ or _globular_ form, which propriety and several of the
+_Phænomena_ that proceed from it, I have more fully explicated in the sixth
+Observation.
+
+One Experiment, which does very much illustrate my present Explication, and
+is in it self exceeding pretty, I must not pass by: And that is a way of
+making small _Globules_ or _Balls_ of Lead, or Tin, as small almost as
+these of Iron or Steel, and that exceeding easily and quickly, by turning
+the filings or chips of those Metals also into perfectly round _Globules_.
+The way, in short, as I received it from the _Learned Physitian Doctor_
+I.G. is this;
+
+Reduce the Metal you would thus shape, into exceeding fine filings, the
+finer the filings are, the finer will the Balls be: _Stratifie_ these
+filings with the fine and well dryed powder of quick Lime in a _Crucible_
+proportioned to the quantity you intend to make: When you have thus filled
+your _Crucible_, by continual _stratifications_ of the filings and powder,
+so that, as neer as may be, no one of the filings may touch another, place
+the _Crucible_ in a _gradual fire_, and by degrees let it be brought to a
+heat big enough to make all the filings, that are mixt with the quick Lime,
+to melt, and no more; for if the fire be too hot, many of these filings
+will joyn and run together; whereas if the heat be proportioned, upon
+washing the Lime-dust in fair Water, all those small filings of the Metal
+will subside to the bottom in a most curious powder, consisting all of
+exactly round _Globules_, which, if it be very fine, is very excellent to
+make Hour-glasses of.
+
+Now though quick Lime be the powder that this direction makes choice of,
+yet I doubt not, but that there may be much more convenient ones found out,
+one of which I have made tryal of, and found very effectual; and were it
+not for discovering, by the mentioning of it, another Secret, which I am
+not free to impart, I should have here inserted it.
+
+       *       *       *       *       *
+
+
+Observ. IX. _Of the Colours observable in Muscovy Glass, and other thin
+Bodies_.
+
+Moscovy-glass, or _Lapis specularis_, is a Body that seems to have as many
+Curiosities in its Fabrick as any common Mineral I have met with: for
+first, It is transparent to a great thickness: Next, it is compounded of an
+infinite number of thin flakes joyned or generated one upon another so
+close & smooth, as with many hundreds of them to make one smooth and thin
+Plate of a transparent flexible substance, which with care and diligence
+may be flit into pieces so exceedingly thin as to be hardly perceivable by
+the eye, and yet even those, which I have thought the thinnest, I have with
+a good _Microscope_ found to be made up of many other Plates, yet thinner;
+and it is probable, that, were our _Microscopes_ much better, we might much
+further discover its divisibility. Nor are these flakes only regular as to
+the smoothness of their Surfaces, but thirdly, In many Plates they may be
+perceived to be terminated naturally with edges of the figure of a
+_Rhomboeid_. This Figure is much more conspicuous in our English talk, much
+whereof is found in the Lead Mines, and is commonly called _Spar_, and
+_Kauck_, which is of the same kind of substance with the _Selenitis_, but
+is seldom found in so large flakes as that is, nor is it altogether so
+tuff, but is much more clear and transparent, and much more curiously
+shaped, and yet may be cleft and flak'd like the other _Selenitis_. But
+fourthly, this stone has a property, which in respect of the _Microscope_,
+is more notable, and that is, that it exhibits several appearances of
+Colours, both to the naked Eye, but much more conspicuously to the
+_Microscope_; for the exhibiting of which, I took a piece of
+_Muscovy-glass_, and splitting or cleaving it into thin Plates, I found
+that up and down in several parts of them I could plainly perceive several
+white specks or flaws, and others diversly coloured with all the Colours of
+the _Rainbow_; and with the _Microscope_ I could perceive, that these
+Colours were ranged in rings that incompassed the white speck or flaw, and
+were round or irregular, according to the shape of the spot which they
+terminated; and the position of Colours, in respect of one another, was the
+very same as in the _Rainbow_. The consecution of those Colours from the
+middle of the spot outward being Blew, Purple, Scarlet, Yellow, Green;
+Blew, Purple, Scarlet, and so onwards, sometimes half a score times
+repeated, that is, there appeared six, seven, eight, nine or ten several
+coloured rings or lines, each incircling the other, in the same manner as I
+have often seen a very _vivid Rainbow_ to have four or five several Rings
+of Colours, that is, accounting all the Gradations between Red and Blew for
+one: But the order of the Colours in these Rings was quite contrary to the
+primary or innermost _Rainbow_, and the same with those of the secondary or
+outermost Rainbow; these coloured Lines or _Irises_, as I may so call them,
+were some of them much brighter then others, and some of them also very
+much broader, they being some of them ten, twenty, nay, I believe, neer a
+hundred times broader then others; and those usually were broadest which
+were neerest the center or middle of the flaw. And oftentimes I found, that
+these Colours reacht to the very middle of the flaw, and then there
+appeared in the middle a very large spot, for the most part, all of one
+colour, which was very vivid, and all the other Colours incompassing it,
+gradually ascending, and growing narrower towards the edges, keeping the
+same order, as in the _secundary Rainbow_, that is, if the middle were
+Blew, the next incompassing it would be a Purple, the third a Red, the
+fourth a Yellow, &c. as above; if the middle were a Red, the next without
+it would be a Yellow, the third a Green, the fourth a Blew, and so onward.
+And this order it alwayes kept whatsoever were the middle Colour.
+
+There was further observable in several other parts of this Body, many
+Lines or Threads, each of them of some one peculiar Colour, and those so
+exceedingly bright and vivid, that it afforded a very pleasant object
+through the _Microscope_. Some of these _threads_ I have observed also to
+be pieced or made up of several short lengths of differently coloured
+_ends_ (as I may so call them) as a line appearing about two inches long
+through the _Microscope_, has been compounded of about half an inch of a
+Peach colour, 1/8 of a lovely Grass-green, 3/4 of an inch more of a bright
+Scarlet, and the rest of the line of a Watchet blew. Others of them were
+much otherwise coloured; the variety being almost infinite. Another thing
+which is very observable, is, that if you find any place where the colours
+are very broad and conspicuous to the naked eye, you may, by pressing that
+place with your finger, make the colours change places, and go from one
+part to another.
+
+There is one _Phænomenon_ more, which may, if care be used, exhibit to the
+beholder, as it has divers times to me, an exceeding pleasant, and not less
+instructive Spectacle; And that is, if curiosity and diligence be used, you
+may so split this admirable Substance, that you may have pretty large
+Plates (in companion of those smaller ones which you may observe in the
+Rings) that are perhaps an 1/8 or a 1/6 part of an inch over, each of them
+appearing through the _Microscope_ most curiously, intirely, and uniformly
+adorned with some one vivid colour: this, if examined with the
+_Microscope_, may be plainly perceived to be in all parts of it equally
+thick. Two, three, or more of these lying one upon another, exhibit
+oftentimes curious compounded colours, which produce such a _Compositum_,
+as one would scarce imagine should be the result of such _ingredients_: As
+perhaps a _faint yellow_ and a _blew_ may produce a very _deep purple_. But
+when anon we come to the more strict examination of these _Phænomena_, and
+to inquire into the causes and reasons of these productions, we shall, I
+hope, make it more conceivable how they are produced, and shew them to be
+no other then the natural and necessary effects arising from the peculiar
+union of concurrent causes.
+
+These _Phænomena_, being so various, and so truly admirable, it will
+certainly be very well worth our inquiry, to examine the causes and reasons
+of them, and to consider, whether from these causes demonstratively
+evidenced, may not be deduced the true causes of the production of all kind
+of Colours. And I the rather now do it, instead of an Appendix or
+Digression to this History, then upon the occasion of examining the Colours
+in Peacocks, or other Feathers, because this Subject, as it does afford
+more variety of particular Colours, so does it afford much better wayes of
+examining each circumstance. And this will be made manifest to him that
+considers, first, that this laminated body is more simple and regular then
+the parts of Peacocks feathers, this consisting only of an indefinite
+number of plain and smooth Plates, heaped up, or _incumbent_ on each other.
+Next, that the parts of this body are much more manageable, to be divided
+or joyned, then the parts of a Peacocks feather, or any other substance
+that I know. And thirdly, because that in this we are able from a
+colourless body to produce several coloured bodies, affording all the
+variety of Colours imaginable: And several others, which the subsequent
+Inquiry will make manifest.
+
+To begin therefore, it is manifest from several circumstances, that the
+material cause of the _apparition_ of these several Colours, is some
+_Lamina_ or Plate of a transparent or pellucid body of a thickness very
+determinate and proportioned according to the greater or less refractive
+power of the _pellucid_ body. And that this is so, abundance of Instances
+and particular Circumstances will make manifest.
+
+As _first_, if you take any small piece of the _Muscovy-glass_, and with a
+Needle, or some other convenient Instrument, cleave it oftentimes into
+thinner and thinner _Laminæ_, you shall find, that till you come to a
+determinate thinness of them, they shall all appear transparent and
+colourless, but if you continue to split and divide them further, you shall
+find at last, that each Plate, after it comes to such a determinate
+thickness, shall appear most lovely ting'd or imbued with a determinate
+colour. If _further_, by any means you so flaw a pretty thick piece, that
+one part does begin to cleave a little from the other, and between those
+two there be by any means gotten some pellucid _medium_, those _laminated_
+pellucid bodies that fill that space, shall exhibit several Rainbows or
+coloured Lines, the colours of which will be disposed and ranged according
+to the various thicknesses of the several parts of that Plate. That this is
+so, is yet _further_ confirmed by this Experiment.
+
+Take two small pieces of ground and polisht Looking-glass-plate, each about
+the bigness of a shilling, take these two dry, and with your fore-fingers
+and thumbs press them very hard and close together, and you shall find,
+that when they approach each other very near, there will appear several
+_Irises_ or coloured Lines, in the same manner almost as in the
+_Muscovy-glass_; and you may very easily change any of the Colours of any
+part of the interposed body, by pressing the Plates closer and harder
+together, or leaving them more lax; that is, a part which appeared coloured
+with a red, may be presently ting'd with a yellow, blew, green, purple, or
+the like, by altering the appropinquation of the terminating Plates. Now
+that air is not necessary to be the interposed body, but that any other
+transparent fluid will do much the same, may be tryed by wetting those
+approximated Surfaces with Water, or any other transparent Liquor, and
+proceeding with it in the same manner as you did with the Air; and you will
+find much the like effect, only with this difference, that those comprest
+bodies, which differ most, in their refractive quality, from the
+compressing bodies, exhibit the most strong and vivid tinctures. Nor is it
+necessary, that this _laminated_ and _ting'd_ body should be of a fluid
+substance, any other substance, provided it be thin enough and transparent,
+doing the same thing: this the _Laminæ_ of our _Muscovy-glass_ hint; but it
+may be confirm'd by multitudes of other Instances.
+
+And first, we shall find, that even Glass it self may, by the help of a
+Lamp, be blown thin enough to produce these _Phænomena_ of Colours: which
+_Phænomena_ accidentally happening, as I have been attempting to frame
+small Glasses with a Lamp, did not a little surprize me at first, having
+never heard or seen any thing of it before; though afterwards comparing it
+with the _Phænomena_, I had often observed in those Bubbles which Children
+use to make with Soap-water, I did the less wonder; especially when upon
+Experiment I found, I was able to produce the same _Phænomena_ in thin
+Bubbles made with any other transparent Substance. Thus have I produced
+them with Bubbles of _Pitch_, _Rosin_, _Colophony_, _Turpentine_,
+_Solutions_ of several _Gums_, as _Gum-Arabick_ in water; any _glutinous_
+Liquor, as _Wort_, _Wine_, _Spirit of Wine_, _Oyl of Turpentine_, _Glare of
+Snails,_ &c.
+
+It would be needless to enumerate the several Instances, these being enough
+to shew the generality or universality of this propriety. Only I must not
+omit, that we have instances also of this kind even in metalline Bodies and
+animal; for those several Colours which are observed to follow each other
+upon the polisht surface of hardned Steel, when it is by a sufficient
+degree of heat gradually tempered or softened, are produced, from nothing
+else but a certain thin _Lamina_ of a _vitrum_ or _vitrified_ part of the
+Metal, which by that degree of heat, and the concurring action of the
+ambient Air, is driven out and fixed on the surface of the Steel.
+
+And this hints to me a very probable (at least, if not the true) cause of
+the hardning and tempering of Steel, which has not, I think, been yet
+given, nor, that I know of been so much as thought of by any. And that is
+this, that the hardness of it arises from a greater proportion of a
+vitrified Substance interspersed through the pores of the Steel. And that
+the tempering or softning of it arises from the proportionate or smaller
+parcels of it left within those pores. This will seem the more probable, if
+we consider these Particulars.
+
+First, That the pure parts of Metals are of themselves very _flexible_ and
+_tuff_; that is, will indure bending and hammering, and yet retain their
+continuity.
+
+Next, That the Parts of all vitrified Substances, as all kinds of Glass,
+the _Scoria_ of Metals, &c. are very hard, and also very brittle, being
+neither _flexible_ nor _malleable_, but may by hammering or beating be
+broken into small parts or powders.
+
+Thirdly, That all Metals (excepting Gold and Silver, which do not so much
+with the bare fire, unless assisted by other saline Bodies) do more or less
+_vitrifie_ by the strength of fire, that is, are corroded by a saline
+Substance, which I elsewhere shew to be the true cause of fire; and are
+thereby, as by several other _Menstruums_ converted into _Scoria_; And this
+is called, _calcining_ of them, by Chimists. Thus Iron and Copper by
+heating and quenching do turn all of them by degrees into _Scoria_, which
+are evidently _vitrified_ Substances, and unite with Glass, and are easily
+_fusible_; and when cold, very hard, and very brittle.
+
+Fourthly, That most kind of _Vitrifications_ or _Calcinations_ are made by
+Salts, uniting and incorporating with the metalline Particles. Nor do I
+know any one _calcination_ wherein a _Saline_ body may not, with very great
+probability, be said to be an agent or coadjutor.
+
+Fifthly, That Iron is converted into Steel by means of the incorporation of
+certain salts, with which it is kept a certain time in the fire.
+
+Sixthly, That any Iron may, in a very little time, be _case hardned_, as
+the Trades-men call it, by casing the iron to be hardned with clay, and
+putting between the clay and iron a good quantity of a mixture of _Urine_,
+_Soot_, _Sea-salt_, and _Horses hoofs_ (all which contein great quantities
+of Saline bodies) and then putting the case into a good strong fire, and
+keeping it in a considerable degree of heat for a good while, and
+afterwards heating, and quenching or cooling it suddenly in cold water.
+
+Seventhly, That all kind of vitrify'd substances, by being suddenly cool'd,
+become very hard and brittle. And thence arises the pretty _Phænomena_ of
+the Glass Drops, which I have already further explained in its own place.
+
+Eighthly, That those metals which are not so apt to vitrifie, do not
+acquire any hardness by quenching in water, as Silver, Gold, &c.
+
+These considerations premis'd, will, I suppose, make way for the more easie
+reception of this following Explication of the _Phænomena_ of hardned and
+temper'd Steel. That Steel is a substance made out of Iron, by means of a
+certain proportionate _Vitrification_ of several parts, which are so
+curiously and proportionately mixt with the more tough and unalter'd parts
+of the Iron, that when by the great heat of the fire this vitrify'd
+substance is melted, and consequently rarify'd, and thereby the pores of
+the Iron are more open, if then by means of dipping it in cold water it be
+suddenly cold, and the parts hardned, that is, stay'd in that same degree
+of _Expansion_ they were in when hot, the parts become very hard and
+brittle, and that upon the same account almost as small parcels of glass
+quenched in water grow brittle, which we have already explicated. If after
+this the piece of Steel be held in some convenient heat, till by degrees
+certain colours appear upon the surface of the brightned metal, the very
+hard and brittle tone of the metal, by degrees relaxes and becomes much
+more tough and soft; namely, the action of the heat does by degrees loosen
+the parts of the Steel that were before streached or set _atilt_ as it
+were, and stayed open by each other, whereby they become relaxed and set at
+liberty, whence some of the more brittle interjacent parts are thrust out
+and melted into a thin skin on the surface of the Steel, which from no
+colour increases to a deep Purple, and so onward by these _gradations_ or
+consecutions, _White, Yellow, Orange, Minium, Scarlet, Purple, Blew,
+Watchet,_ &c. and the parts within are more conveniently, and
+proportionately mixt; and so they gradually subside into a texture which is
+much better proportion'd and closer joyn'd, whence that rigidnesse of parts
+ceases, and the parts begin to acquire their former _ductilness_.
+
+Now, that 'tis nothing but the vitrify'd metal that sticks upon the surface
+of the colour'd body, is evident from this, that if by any means it be
+scraped and rubb'd off, the metal underneath it is white and clear; and if
+it be kept longer in the fire, so as to increase to a considerable
+thickness, it may, by blows, be beaten off in flakes. This is further
+confirm'd by this observable, that that Iron or Steel will keep longer from
+rusting which is covered with this vitrify'd case: Thus also Lead will, by
+degrees, be all turn'd into a litharge; for that colour which covers the
+top being scum'd or shov'd aside, appears to be nothing else but a litharge
+or vitrify'd Lead.
+
+This is observable also in some sort, on Brass, Copper, Silver, Gold, Tin,
+but is most conspicuous in Lead: all those Colours that cover the surface
+of the Metal being nothing else, but a very thin vitrifi'd part of the
+heated Metal.
+
+The other Instance we have, is in Animal bodies, as in Pearls, Mother of
+Pearl-shels, Oyster-shels, and almost all other kinds of stony shels
+whatsoever. This have I also sometimes with pleasure observ'd even in
+Muscles and Tendons. Further, if you take any glutinous substance and run
+it exceedingly thin upon the surface of a smooth glass or a polisht
+metaline body, you shall find the like effects produced: and in general,
+wheresoever you meet with a transparent body thin enough, that is
+terminated by reflecting bodies of differing refractions from it, there
+will be a production of these pleasing and lovely colours.
+
+Nor is it necessary, that the two _terminating_ Bodies should be both of
+the same kind, as may appear by the _vitrified Laminæ_ on _Steel_, _Lead_,
+and other Metals, one surface of which _Laminæ_ is contiguous to the
+surface of the Metal, the other to that of the Air.
+
+Nor is it necessary, that these colour'd _Laminæ_ should be of an even
+thickness, that is, should have their edges and middles of equal thickness,
+as in a Looking-glass-plate, which circumstance is only requisite to make
+the Plate appear all of the same colour; but they may resemble a _Lens_,
+that is, have their middles thicker then their edges; or else a _double
+concave_, that is, be thinner in the middle then at the edges; in both
+which cases there will be various coloured rings or lines, with differing
+consecutions or orders of Colours; the order of the first from the middle
+outwards being Red, Yellow, Green, Blew, &c. And the latter quite contrary.
+
+But further, it is altogether necessary, that the Plate, in the places
+where the Colours appear, should be of a determinate thickness: First, It
+must not be more then such a thickness, for when the Plate is increased to
+such a thickness, the Colours cease; and besides, I have seen in a thin
+piece of _Muscovy-glass_, where the two ends of two Plates, which appearing
+both single, exhibited two distinct and differing Colours; but in that
+place where they were united, and constituted one double Plate (as I may
+call it) they appeared transparent and colourless. Nor, Secondly, may the
+Plates be _thinner_ then such a determinate _cize_; for we alwayes find,
+that the very outmost Rim of these flaws is terminated in a white and
+colourless Ring.
+
+Further, in this Production of Colours there is no need of a determinate
+Light of such a bigness and no more, nor of a determinate position of that
+Light, that it should be on this side, and not on that side; nor of a
+terminating shadow, as in the Prisme, and Rainbow, or Water-ball: for we
+find, that the Light in the open Air, either in or out of the Sun-beams,
+and within a Room, either from one or many Windows, produces much the same
+effect: only where the Light is brightest, there the Colours are most
+_vivid_. So does the light of a Candle, collected by a Glass-ball. And
+further, it is all one whatever side of the coloured Rings be towards the
+light; for the whole Ring keeps its proper Colours from the middle outwards
+in the same order as I before related, without varying at all, upon
+changing the position of the light.
+
+But above all it is most observable, that here are all kind of Colours
+generated in a _pellucid_ body, where there is properly no such refraction
+as _Des Cartes_ supposes his _Globules_ to acquire a _vertuity_ by: For in
+the plain and even Plates it is manifest, that the second refraction
+(according to _Des Cartes_ his Principles in the _fifth section of the
+eighth Chapter of his Meteors_) does regulate and restore the supposed
+_turbinated Globules_ unto their former uniform motion. This Experiment
+therefore will prove such a one as our _thrice excellent Verulam_ calls
+_Experimentum Crucis_, serving as a Guide or Land-mark, by which to direct
+our course in the search after the true cause of Colours. Affording us this
+particular negative Information, that for the production of Colours there
+is not necessary either a great refraction, as in the Prisme; nor Secondly,
+a determination of Light and shadow, such as is both in the Prisme and
+Glass-ball. Now that we may see likewise what affirmative and positive
+Instruction it yields, it will be necessary, to examine it a little more
+particularly and strictly; which that we may the better do, it will be
+requisite to premise somewhat in general concerning the nature of Light and
+Refraction.
+
+And first for Light it seems very manifest, that there is no luminous Body
+but has the parts of it in motion more or less.
+
+First, That all kind of _fiery burning Bodies_ have their parts in motion,
+I think, will be very easily granted me. That the _spark_ struck from a
+Flint and Steel is in a rapid agitation, I have elsewhere made probable.
+And that the Parts of _rotten Wood_, _rotten Fish_ and the like, are also
+in motion, I think, will as easily be conceded by those, who consider, that
+those parts never begin to shine till the Bodies be in a state of
+putrefaction; and that is now generally granted by all, to be caused by the
+motion of the parts of putrifying bodies. That the _Bononian stone_ shines
+no longer then it is either warmed by the Sun-beams, or by the flame of a
+Fire or of a Candle, is the general report of those that write of it, and
+of others that have seen it. And that heat argues a motion of the internal
+parts is (as I said before) generally granted.
+
+But there is one Instance more, which was first shewn to the _Royal
+Society_ by Mr. _Clayton_ a worthy Member thereof, which does make this
+Assertion more evident then all the rest: And that is, That a _Diamond_
+being _rub'd_, _struck_ or _heated_ in the dark, shines for a pretty while
+after, so long as that motion, which is imparted by any of those Agents,
+remains (in the same manner as a Glass, rubb'd, struck, or (by a means
+which I shall elsewhere mention) heated, yields a sound which lasts as long
+as the vibrating motion of that _sonorous_ body) several Experiments made
+on which Stone, are since published in a Discourse of Colours, by the truly
+honourable Mr. _Boyle_. What may be said of those _Ignes fatui_ that appear
+in the night, I cannot so well affirm, having never had the opportunity to
+examine them my self, nor to be inform'd by any others that had observ'd
+them: And the relations of them in Authors are so imperfect, that nothing
+can be built on them. But I hope I shall be able in another place to make
+it at least very probable, that there is even in those also a Motion which
+causes this effect. That the shining of _Sea-water_ proceeds from the same
+cause, may be argued from this, That it shines not till either it be beaten
+against a Rock, or be some other wayes broken or agitated by Storms, or
+Oars, or other _percussing_ bodies. And that the Animal _Energyes_ or
+Spirituous _agil_ parts are very active in _Cats eyes_ when they shine,
+seems evident enough, because their eyes never shine but when they look
+very intensly either to find their prey, or being hunted in a dark room,
+when they seek after their adversary, or to find a way to escape. And the
+like may be said of the shining _Bellies of Gloworms_; since 'tis evident
+they can at pleasure either increase or extinguish that Radiation.
+
+It would be somewhat too long a work for this place _Zetetically_ to
+examine, and positively to prove, what particular kind of motion it is that
+must be the efficient of Light; for though it be a motion, yet 'tis not
+every motion that produces it, since we find there are many bodies very
+violently mov'd, which yet afford not such an effect; and there are other
+bodies, which to our other senses, seem not mov'd so much, which yet shine.
+Thus Water and quick-silver, and most other liquors heated, shine not; and
+several hard bodies, as Iron, Silver, Brass, Copper, Wood, &c. though very
+often struck with a hammer, shine not presently, though they will all of
+them grow exceeding hot; whereas rotten Wood, rotten Fish, Sea water,
+Gloworms, &c. have nothing of tangible heat in them, and yet (where there
+is no stronger light to affect the Sensory) they shine some of them so
+Vividly, that one may make a shift to read by them.
+
+It would be too long, I say, here to insert the discursive progress by
+which I inquir'd after the proprieties of the motion of Light, and
+therefore I shall only add the result.
+
+And, First, I found it ought to be exceeding _quick_, such as those motions
+of _fermentation_ and _putrefaction_, whereby, certainly, the parts are
+exceeding nimbly and violently mov'd; and that, because we find those
+motions are able more minutely to shatter and divide the body, then the
+most violent heats _menstruums_ we yet know. And that fire is nothing else
+but such a _dissolution_ of the Burning body, made by the most _universal
+menstruum_ of all _sulphureous bodies_, namely, the Air, we shall in an
+other place of this Tractate endeavour to make probable. And that, in all
+extreamly hot shining bodies, there is a very quick motion that causes
+Light, as well as a more robust that causes Heat, may be argued from the
+celerity wherewith the bodyes are dissolv'd.
+
+Next, it must be a _Vibrative motion_. And for this the newly mention'd
+_Diamond_ affords us a good argument; since if the motion of the parts did
+not return, the Diamond must after many rubbings decay and be wasted: but
+we have no reason to suspect the latter, especially if we consider the
+exceeding difficulty that is found in cutting or wearing away a Diamond.
+And a Circular motion of the parts is much more improbable, since, if that
+were granted, and they be suppos'd irregular and Angular parts, I see not
+how the parts of the Diamond should hold so firmly together, or remain in
+the same sensible dimensions, which yet they do. Next, if they be
+_Globular_, and mov'd only with a _turbinated_ motion, I know not any cause
+that can impress that motion upon the _pellucid medium_, which yet is done.
+Thirdly, any other _irregular_ motion of the parts one amongst another,
+must necessarily make the body of a fluid consistence, from which it is far
+enough. It must therefore be a _Vibrating_ motion.
+
+And Thirdly, That it is a very _short-vibrating motion_, I think the
+instances drawn from the shining of Diamonds will also make probable. For a
+Diamond being the hardest body we yet know in the World, and consequently
+the least apt to yield or bend, must consequently also have its
+_vibrations_ exceeding short.
+
+And these, I think, are the three principal proprieties of a motion,
+requisite to produce the effect call'd Light in the Object.
+
+The next thing we are to consider, is the way or manner of the _trajection_
+of this motion through the interpos'd pellucid body to the eye: And here it
+will be easily granted,
+
+First, That it must be a body _susceptible_ and _impartible_ of this motion
+that will deserve the name of a Transparent. And next, that the parts of
+such a body must be _Homogeneous_, or of the same kind. Thirdly, that the
+constitution and motion of the parts must be such, that the appulse of the
+luminous body may be communicated or propagated through it to the greatest
+imaginable distance in the least imaginable time, though I see no reason to
+affirm, that it must be in an instant: For I know not any one Experiment or
+observation that does prove it. And, whereas it may be objected, That we
+see the Sun risen at the very instant when it is above the sensible
+Horizon, and that we see a Star hidden by the body of the Moon at the same
+instant, when the Star, the Moon, and our Eye are all in the same line; and
+the like Observations, or rather suppositions, may be urg'd. I have this to
+answer, That I can as easily deny as they affirm; for I would fain know by
+what means any one can be assured any more of the Affirmative, then I of
+the Negative. If indeed the propagation were very slow, 'tis possible
+something might be discovered by Eclypses of the Moon; but though we should
+grant the progress of the light from the Earth to the Moon, and from the
+Moon back to the Earth again to be full two Minutes in performing, I know
+not any possible means to discover it; nay, there may be some instances
+perhaps of Horizontal Eclypses that may seem very much to favour this
+supposition of the slower progression of Light then most imagine. And the
+like may be said of the Eclypses of the Sun, &c. But of this only by the
+by. Fourthly, That the motion is propagated every way through an
+_Homogeneous medium_ by _direct_ or _straight_ lines extended every way
+like Rays from the center of a Sphere. Fifthly, in an _Homogeneous medium_
+this motion is propagated every way with _equal velocity_, whence
+necessarily every _pulse_ or _vitration_ of the luminous body will generate
+a Sphere, which will continually increase, and grow bigger, just after the
+same manner (though indefinitely swifter) as the waves or rings on the
+surface of the water do swell into bigger and bigger circles about a point
+of it, where, by the sinking of a Stone the motion was begun, whence it
+necessarily follows, that all the parts of these Spheres undulated through
+an _Homogeneous medium_ cut the Rays at right angles.
+
+But because all transparent _mediums_ are not _Homogeneous_ to one another,
+therefore we will next examine how this pulse or motion will be propagated
+through differingly transparent _mediums_. And here, according to the most
+acute and excellent Philosopher _Des Cartes_, I suppose the sign of the
+angle of inclination in the first _medium_ to be to the sign of refraction
+in the second, As the density of the first, to the density of the second.
+By density, I mean not the density in respect of gravity (with which the
+refractions or transparency of _mediums_ hold no proportion) but in respect
+onely to the _trajection_ of the Rays of light, in which respect they only
+differ in this; that the one propagates the pulse more easily and weakly,
+the other more slowly, but more strongly. But as for the pulses themselves,
+they will by the refraction acquire another propriety, which we shall now
+endeavour to explicate.
+
+We will suppose therefore in the first Figure ACFD to be a physical Ray, or
+ABC and DEF to be two Mathematical Rays, _trajected_ from a very remote
+point of a luminous body through an _Homogeneous_ transparent _medium_ LLL,
+and DA, EB, FC, to be small portions of the orbicular impulses which must
+therefore cut the Rays at right angles; these Rays meeting with the plain
+surface NO of a _medium_ that yields an easier _transitus_ to the
+propagation of light, and falling _obliquely_ on it, they will in the
+_medium_ MMM be refracted towards the perpendicular of the surface. And
+because this _medium_ is more easily _trajected_ then the former by a
+third, therefore the point C of the orbicular pulse FC will be mov'd to H
+four spaces in the same time that F the other end of it is mov'd to G three
+spaces, therefore the whole refracted pulse GH shall be _oblique_ to the
+refracted Rays CHK and GI; and the angle GHC shall be an acute, and so much
+the more acute by how much the greater the refraction be, then which
+nothing is more evident, for the sign of the inclination is to the sign of
+refraction as GF to TC the distance between the point C and the
+perpendicular from G on CK, which being as four to three, HC being longer
+then GF is longer also then TC, therefore the angle GHC is less than GTC.
+So that henceforth the parts of the pulses GH and IK are mov'd ascew, or
+cut the Rays at _oblique_ angles.
+
+It is not my business in this place to set down the reasons why this or
+that body should impede the Rays more, others less: as why Water should
+transmit the Rays more easily, though more weakly than air. Onely thus much
+in general I shall hint, that I suppose the _medium_ MMM to have less of
+the transparent undulating subtile matter, and that matter to be less
+implicated by it, whereas LLL I suppose to contain a greater quantity of
+the fluid undulating substance, and this to be more implicated with the
+particles of that _medium_.
+
+But to proceed, the same kind of _obliquity_ of the Pulses and Rays will
+happen also when the refraction is made out of a more easie into a more
+difficult _mediu_; as by the calculations of GQ & CSR which are refracted
+from the perpendicular. In both which calculations 'tis _obvious_ to
+observe, that always that part of the Ray towards which the refraction is
+made has the end of the _orbicular pulse_ precedent to that of the other
+side. And always, the oftner the refraction is made the same way, Or the
+greater the single refraction is, the more is this unequal progress. So
+that having found this odd propriety to be an inseparable concomitant of a
+refracted Ray, not streightned by a contrary refraction, we will next
+examine the refractions of the Sun-beams, as they are suffer'd onely to
+pass through a small passage, _obliquely_ out of a more difficult, into a
+more easie _medium_.
+
+Let us suppose therefore ABC in the second Figure to represent a large
+_Chimical Glass-body_ about two foot long, filled with very fair Water as
+high as AB, and inclin'd in a convenient posture with B towards the Sun:
+Let us further suppose the top of it to be cover'd with an _opacous_ body,
+all but the hole ab, through which the Sun-beams are suffer'd to pass into
+the Water, and are thereby refracted to cdef, against which part, if a
+Paper be expanded on the outside, there will appear all the colours of the
+Rain-bow, that is, there will be generated the two principal colours,
+_Scarlet_ and _Blue_, and all the _intermediate_ ones which arise from the
+composition and dilutings of these two, that is, cd shall exhibit a
+_Scarlet_, which toward d is diluted into a _Yellow_; this is the
+refraction of the Ray, ik, which comes from the underside of the Sun; and
+the Ray ef shall appear of a deep _Blue_, which is gradually towards e
+diluted into a pale _Watchet-blue_. Between d and e the two _diluted_
+colours. _Blue_ and _Yellow_ are mixt and compounded into a _Green_; and
+this I imagine to be the reason why _Green_ is so acceptable a colour to
+the eye, and that either of the two extremes are, if intense, rather a
+little offensive, namely, the being plac'd in the middle between the two
+extremes, and compounded out of both those, _diluted_ also, or somewhat
+qualifi'd, for the _composition_, arising from the mixture of the two
+extremes _undiluted_, makes a _Purple_, which though it be a lovely colour,
+and pretty acceptable to the eye, yet is it nothing comparable to the
+ravishing pleasure with which a curious and well tempered _Green_ affects
+the eye. If removing the Paper, the eye be plac'd against cd, it will
+perceive the lower side of the Sun (or a Candle at night which is much
+better, because it offends not the eye, and is more easily manageable) to
+be of a deep _Red_, and if against ef it will perceive the upper part of
+the luminous body to be of a deep _Blue_; and these colours will appear
+deeper and deeper, according as the Rays from the luminous body fall more
+_obliquely_ on the surface of the Water, and thereby suffer a greater
+refraction, and the more distinct, the further cdef is removed from the
+trajecting hole.
+
+So that upon the whole, we shall find that the reason of the _Phænomena_
+seems to depend upon the _obliquity_ of the _orbicular pulse_, to the Lines
+of Radiation, and in particular, that the Ray cd which constitutes the
+_Scarlet_ has its inner parts, namely those which are next to the middle of
+the luminous body, precedent to the outermost which are contiguous to the
+dark and _unradiating_ skie. And that the Ray ef which gives a _Blue_, has
+its outward part, namely, that which is contiguous to the dark side
+precedent to the pulse from the innermost, which borders on the bright
+_area_ of the luminous body.
+
+We may observe further, that the cause of the _diluting_ of the colours
+towards the middle, proceeds partly from the wideness of the hole through
+which the Rays pass, whereby the Rays from several parts of the luminous
+body, fall upon many of the same parts between c and f as is more manifest
+by the Figure: And partly also from the nature of the refraction it self,
+for the vividness or strength of the two terminating colours, arising
+chiefly as we have seen, from the very great difference that is betwixt the
+outsides of those _oblique undulations_ & the dark Rays circumambient, and
+that disparity betwixt the _approximate_ Rays, decaying gradually: the
+further inward toward the middle of the luminous body they are remov'd, the
+more must the colour approach to a white or an undisturbed light.
+
+Upon the calculation of the refraction and reflection from a Ball of Water
+or Glass, we have much the same _Phænomena_, namely, an _obliquity_ of the
+undulation in the same manner as we have found it here. Which, because it
+is very much to our present purpose, and affords such an _Instancia
+crucis_, as no one that I know has hitherto taken notice of, I shall
+further examine. For it does very plainly and positively distinguish, and
+shew, which of the two _Hypotheses_, either the _Cartesian_ or this is to
+be followed, by affording a generation of all the colors in the Rainbow,
+where according to the _Cartesian Principles_ there should be none at all
+generated. And secondly, by affording an instance that does more closely
+confine the cause of these _Phænomena_ of colours to this present
+_Hypothesis_.
+
+And first, for the _Cartesian_, we have this to object against it, That
+whereas he says (_Meteorum Cap. 8. Sect. 5._) _Sed judicabam unicam
+(refractione scilicet) ad minimum requiri, & quidem talem ut ejus effectus
+aliâ contrariâ (refractione) non destruatur: Nam experientia docet si
+superficies _NM_ & _NP_ (nempe refringentes) Parallelæ forent, radios
+tantundem per alteram iterum erectos quantum per unam frangerentur, nullos
+colores depicturos_; This Principle of his holds true indeed in a prisme
+where the refracting surfaces are plain, but is contradicted by the Ball or
+Cylinder, whether of Water Or Glass, where the refracting surfaces are
+Orbicular or Cylindrical. For if we examine the passage of any _Globule_ or
+Ray of the primary _Iris_, we shall find it to pass out of the Ball or
+Cylinder again, with the same inclination and refraction that it enter'd in
+withall, and that that last refraction by means of the _intermediate_
+reflection shall be the same as if without any reflection at all the Ray
+had been twice refracted by two Parallel surfaces.
+
+And that this is true, not onely in one, but in every Ray that goes to the
+constitution of the Primary Iris; nay, in every Ray, that suffers only two
+refractions, and one reflection, by the surface of the round body, we shall
+presently see most evident, if we repeat the _Cartesian Scheme_, mentioned
+in the tenth _Section_ of the eighth _Chapter_ of his _Meteors_, where
+EFKNP in the third Figure[9] is one of the Rays of the Primary Iris, twice
+refracted at F and N, and once reflected at K by the surface of the
+Water-ball. For, first it is evident, that KF and KN are equal, because KN
+being the reflected part of KF they have both the same inclination on the
+surface K that is the angles FKT, and NKV made by the two Rays and the
+Tangent of K are equal, which is evident by the Laws of reflection; whence
+it will follow also, that KN has the same inclination on the surface N, or
+the Tangent of it XN that the Ray KF has to the surface F, or the Tangent
+of it FY, whence it must necessarily follow, that the refractions at F and
+N are equal, that is, KFE and KNP are equal. Now, that the surface N is by
+the reflection at K made parallel to the surface at F, is evident from the
+principles of reflection; for reflection being nothing but an inverting of
+the Rays, if we re-invert the Ray KNP, and make the same inclinations below
+the line TKV that it has above, it will be most evident, that KH the
+inverse of KN will be the continuation of the line FK, and that LHI the
+inverse of OX is parallel to FY. And HM the inverse of NP is Parallel to EF
+for the angle KHI is equal to KNO which is equal to KFY, and the angle KHM
+is equal to KNP which is equal to KFE which was to be prov'd.
+
+So that according to the above mentioned _Cartesian_ principles there
+should be generated no colour at all in a Ball of Water or Glass by two
+refractions and one reflection, which does hold most true indeed, if the
+surfaces be plain, as may be experimented with any kind of prisme where the
+two refracting surfaces are equally inclin'd to the reflecting; but in this
+the _Phænomena_ are quite otherwise.
+
+The cause therefore of the generation of colour must not be what _Des
+Cartes_ assigns, namely, a certain _rotation_ of the _Globuli ætherei_,
+which are the particles which he supposes to constitute the _Pellucid
+medium_, But somewhat else, perhaps what we have lately supposed, and shall
+by and by further prosecute and explain.
+
+But, First I shall crave leave to propound some other difficulties of his,
+notwithstanding exceedingly ingenious _Hypothesis_, which I plainly confess
+to me seem such; and those are,
+
+First, if that light be (as is affirmed, _Diopt._ cap. 1. §. 8.) not so
+properly a motion, as an action or propension to motion, I cannot conceive
+how the eye can come to be sensible of the _verticity_ of a _Globule_,
+which is generated in a drop of Rain, perhaps a mile off from it. For that
+_Globule_ is not carry'd to the eye according to his formerly recited
+Principle; and if not so, I cannot conceive how it can communicate its
+_rotation_, or circular motion to the line of the _Globules_ between the
+drop and the eye. It cannot be by means of every ones turning the next
+before him; for if so, then onely all the _Globules_ that are in the odd
+places must be turned the same way with the first, namely, the 3. 5. 7. 9.
+11, &c. but all the _Globules_ interposited between them in the even
+places; namely, the 2. 4. 6. 8. 10. &c. must be the quite contrary, whence,
+according to the _Cartesian Hypothesis_, there must be no distinct colour
+generated, but a confusion. Next, since the _Cartesian Globuli_ are
+suppos'd (_Principiorum Philosoph._ Part. 3. §. 86.) to be each of them
+continually in motion about their centers, I cannot conceive how the eye is
+able to distinguish this new generated motion from their former inherent
+one, if I may so call that other wherewith they are mov'd or _turbinated_,
+from some other cause than refraction. And thirdly, I cannot conceive how
+these motions should not happen sometimes to oppose each other, and then,
+in stead of a _rotation_, there would be nothing but a direct motion
+generated, and consequently no colour. And fourthly, I cannot conceive, how
+by the _Cartesian Hypothesis_ it is possible to give any plausible reason
+of the nature of the Colours generated in the thin _laminæ_ of these our
+_Microscopical Observations_; for in many of these, the refracting and
+reflecting surfaces are parallel to each other, and consequently no
+_rotation_ can be generated, nor is there any necessity of a shadow or
+termination of the bright Rays, such as is suppos'd (_Chap._ 8. §. 5. _Et
+præterea observavi umbram quoque, aut limitationem luminis requiri:_ and
+_Chap._ 8. §. 9.) to be necessary to the generation of any distinct
+colours; Besides that, here is oftentimes one colour generated without any
+of the other appendant ones, which cannot be by the _Cartesian Hypothesis_.
+
+There must be therefore some other propriety of refraction that causes
+colour. And upon the examination of the thing, I cannot conceive any one
+more general, inseparable, and sufficient, than that which I have before
+assign'd. That we may therefore see how exactly our _Hypothesis_ agrees
+also with the _Phænomena_ of the refracting round body, whether _Globe_ or
+_Cylinder_, we shall next subjoyn our _Calculation_ or _Examen_ of it.
+
+And to this end, we will calculate any two Rays: as for instance;[10] let
+EF be a Ray cutting the _Radius_ CD (divided into 20. parts) in G 16. parts
+distant from C, and ef another Ray, which cuts the same _Radius_ in g 17.
+parts distant, these will be refracted to K and k, and from thence
+reflected to N and n, and from thence refracted toward P and p; therefore
+the Arch Ff will be 5.d 5'. The Arch FK 106.d 30'. the Arch fk 101.d 2'.
+The line FG 6000. and fg 5267. therefore hf. 733. therefore Fc 980, almost.
+The line FK 16024. and fk 15436. therefore Nd 196. and no 147 almost, the
+line Nn 1019 the Arch Nn 5.d 51'. therefore the Angle Nno is 34.d 43'.
+therefore the Angle Non is 139.d 56'. which is almost 50.d more than a
+right Angle.
+
+It is evident therefore by this _Hypothesis_, that at the same time that ef
+touches f. EF is arrived at c. And by that time efkn is got to n, EFKN is
+got to d and when it touches N, the pulse of the other Ray is got to o. and
+no farther, which is very short of the place it should have arriv'd to, to
+make the Ray np to cut the _orbicular pulse_ No at right Angles: therefore
+the Angle Nop is an acute Angle, but the quite contrary of this will
+happen, if 17. and 18. be calculated in stead of 16. and 17. both which
+does most exactly agree with the _Phænomena_: For if the Sun, or a Candle
+(which is better) be placed about Ee, and the eye about Pp, the Rays EFef
+at 16. and 17. will paint the side of the luminous object toward np _Blue_,
+and towards NP _Red_. But the quite contrary will happen when EF is 17. and
+ef 18. for then towards NP shall be a _Blue_, and towards np a _Red_,
+exactly according to the calculation. And there appears the _Blue_ of the
+Rainbow, where the two _Blue_ sides of the two Images unite, and there the
+_Red_ where the two _Red_ sides unite, that is, where the two Images are
+just disappearing; which is, when the Rays EF and NP produc'd till they
+meet, make an Angle of about 41. and an half; the like union is there of
+the two Images in the Production of the _Secundary Iris_, and the same
+causes, as upon calculation may appear; onely with this difference, that it
+is somewhat more faint, by reason of the duplicate reflection, which does
+always weaken the impulse the oftner it is repeated.
+
+Now, though the second refraction made at Nn be convenient, that is, do
+make the Rays glance the more, yet is it not altogether requisite; for it
+is plain from the calculation, that the pulse dn is sufficiently _oblique_
+to the Rays KN and kn, as wel as the pulse fc is _oblique_ to the Rays FK &
+fk. And therefore if a piece of very fine Paper be held close against Nn
+and the eye look on it either through the Ball as from D, or from the other
+side, as from B. there shall appear a Rainbow, or colour'd line painted on
+it with the part toward X appearing _Red_, towards O, _Blue_; the same also
+shall happen, if the Paper be placed about Kk, for towards T shall appear a
+_Red_, and towards V a _Blue_, which does exactly agree with this my
+_Hypothesis_, as upon the calculation of the progress of the pulse will
+most easily appear.
+
+Nor do these two observations of the colours appearing to the eye about p
+differing from what they appear on the Paper at N contradict each other;
+but rather confirm and exactly agree with one another, as will be evident
+to him that examines the reasons set down by the ingenious. _Des Cartes_ in
+the 12. _Sect._ of the 8. _Chapter of his Meteors_, where he gives the true
+reason why the colours appear of a quite contrary order to the eye, to what
+they appear'd on the Paper if the eye be plac'd in steed of the Paper: And
+as in the Prisme, so also in the Water-drop, or Globe the _Phænomena_, and
+reason are much the same.
+
+Having therefore shewn that there is such a propriety in the _prisme_ and
+water _Globule_ whereby the pulse is made _oblique_ to the progressive, and
+that so much the more, by how much greater the refraction is, I shall in
+the next place consider, how this conduces to the production of colours,
+and what kind of impression it makes upon the bottom of the eye; and to
+this end it will be requisite to examine this _Hypothesis_ a little more
+particularly.
+
+First therefore, if we consider the manner of the progress of the pulse, it
+will seem rational to conclude, that that part or end of the pulse which
+precedes the other, must necessarily be somwhat more _obtunded_, or
+_impeded_ by the resistance of the transparent _medium_, than the other
+part or end of it which is subsequent, whose way is, as it were, prepared
+by the other; especially if the adjacent _medium_ be not in the same manner
+enlightned or agitated. And therefore (in the fourth _Figure_ of the sixth
+_Iconism_) the Ray AAAHB will have its side HH more deadned by the
+resistance of the dark or quiet _medium_ PPP, Whence there will be a kind
+of deadness superinduc'd on the side HHH, which will continually increase
+from B, and strike deeper and deeper into the Ray by the line BR; Whence
+all the parts of the triangle, RBHO will be of a dead _Blue_ colour, and so
+much the deeper, by how much the nearer they lie to the line BHH, which is
+most deaded or impeded, and so much the more _dilute_, by how much the
+nearer it approaches the line BR. Next on the other side of the Ray AAN,
+the end A of the pulse AH will be promoted, or made stronger, having its
+passage already prepar'd as 'twere by the other parts preceding, and so its
+impression wil be stronger; And because of its _obliquity_ to the Ray,
+there will be propagated a kind of faint motion into QQ the adjacent dark
+or quiet _medium_, which faint motion will spread further and further into
+QQ as the Ray is propagated further and further from A, namely, as far as
+the line MA, whence all the triangle MAN will be ting'd with a _Red_, and
+that _Red_ will be the deeper the nearer it approaches the line MA, and the
+_paler_ or _yellower_ the nearer it is the line NA. And if the Ray be
+continued, so that the lines AN and BR (which are the bounds of the _Red_
+and _Blue diluted_) do meet and cross each other, there will be beyond that
+intersection generated all kinds of _Greens_.
+
+Now, these being the proprieties of every single refracted Ray of light, it
+will be easie enough to consider what must be the result of very many such
+Rays collateral: As if we suppose infinite such Rays _interjacent_ between
+AKSB and ANOB, which arc the terminating: For in this case the Ray AKSB
+will have its _Red_ triangle intire, as lying next to the dark or quiet
+_medium_, but the other side of it BS will have no _Blue_, because the
+_medium adjacent_ to it SBO, is mov'd or enlightned, and consequently that
+light does destroy the colour. So likewise will the Ray ANOB lose its
+_Red_, because the _adjacent medium_ is mov'd or enlightned, but the other
+side of the Ray that is _adjacent_ to the dark, namely, AHO will preserve
+its _Blue_ entire, and these Rays must be so far produc'd as till AN and BR
+cut each other, before there will be any _Green_ produc'd. From these
+Proprieties well consider'd, may be deduc'd the reasons of all the
+_Phænomena_ of the _prisme_, and of the _Globules_ or drops of Water which
+conduce to the production of the Rainbow.
+
+Next for the impression they make on the _Retina_, we will further examine
+this _Hypothesis_: Suppose therefore ABCDEF, in the fifth _Figure_, to
+represent the Ball of the eye: on the _Cornea_ of which ABC two Rays GACH
+and KCAI (which are the terminating Rays of a luminous body) falling, are
+by the refraction thereof collected or _converg'd_ into two points at the
+bottom of the eye. Now, because these terminating Rays, and all the
+_intermediate_ ones which come from any part of the luminous body, are
+suppos'd by some sufficient refraction before they enter the eye, to have
+their pulses made _oblique_ to their progression, and consequently each Ray
+to have potentially _superinduc'd_ two proprieties, or colours, viz., a
+_Red_ on the one side, and a _Blue_ on the other, which notwithstanding are
+never actually manifest, but when this or that Ray has the one or the other
+side of it bordering on a dark or unmov'd _medium_, therefore as soon as
+these Rays are entred into the eye and so have one side of each of them
+bordering on a dark part of the humours of the eye, they will each of them
+actually exhibit some colour; therefore ADC the production of GACH will
+exhibit a _Blue_, because the side CD is _adjacent_ to the dark _medium_
+CQDC, but nothing of a _Red_, because its side AD is _adjacent_ to the
+enlightned _medium_ ADFA: And all the Rays that from the points of the
+luminous body are collected on the parts of the _Retina_ between D and F
+shall have their _Blue_ so much the more _diluted_ by how much the farther
+these points of collection are distant from D towards F; and the Ray AFC
+the production of KCAI, will exhibit a _Red_, because the side AF is
+adjacent to the dark or quiet _medium_ of the eye APFA, but nothing of a
+_Blue_, because its side CF is _adjacent_ to the enlightned _medium_ CFDC,
+and all the Rays from the intermediate parts of the luminous body that are
+collected between F and D shall have their _Red_ so much the more diluted,
+by how much the farther they are distant from F towards D.
+
+Now, because by the refraction in the _Cornea_, and some other parts of the
+eye, the sides of each Ray, which before were almost parallel, are made to
+_converge_ and meet in a point at the bottom of the eye, therefore that
+side of the _pulse_ which preceded before these refractions, shall first
+touch the _Retina_, and the other side last. And therefore according as
+this or that side, or end of the pulse shall be impeded, accordingly will
+the _impressions_ on the _Retina_ be varied; therefore by the Ray GACH
+refracted by the _Cornea_ to D there shall be on that point a stroke or
+impression confus'd, whose weakest end, namely, that by the line CD shall
+precede, and the stronger, namely, that by the line AD shall follow. And by
+the Ray KCAI refracted to F, there shall be on that part a confus'd stroke
+or impression, whose strongest part, namely, that by the line CF shal
+precede, and whose weakest or impeded, namely, that by the line AF shall
+follow, and all the intermediate points between F and D will receive
+impressions from the _converg'd_ Rays so much the more like the impressions
+on F and D by how much the nearer they approach that or this.
+
+From the consideration of the proprieties of which impressions, we may
+collect these short definitions of Colours: That _Blue is an impression on
+the Retina of an oblique and confus'd pulse of light, whose weakest part
+precedes, and whose strongest follows._ And, that _Red is an impression on
+the Retina of an oblique and confus'd pulse of light, whose strongest part
+precedes, and whose weakest follows._
+
+Which proprieties, as they have been already manifested, in the Prisme and
+falling drops of Rain, to be the causes of the colours there generated, may
+be easily found to be the efficients also of the colours appearing in thin
+_laminated_ transparent bodies; for the explication of which, all this has
+been premised.
+
+And that this is so, a little closer examination of the _Phænomena_ and the
+_Figure_ of the body, by this _Hypothesis_ will make evident.
+
+For first (as we have already observed) the _laminated_ body must be of a
+determinate thickness, that is, it must not be thinner then such a
+determinate quantity; for I have always observ'd, that neer the edges of
+those which are exceeding thin, the colours disappear, and the part grows
+white; nor must it be thicker then another determinate quantity; for I have
+likewise observ'd, that beyond such a thickness, no colours appear'd, but
+the Plate looked white, between which two determinate thicknesses were all
+the colour'd Rings; of which in some substances I have found ten or twelve,
+in others not half so many, which I suppose depends much upon the
+transparency of the _laminated_ body. Thus though the consecutions are the
+same in the scumm or the skin on the top of metals; yet in those
+consecutions in the same colour is not so often repeated as in the
+consecutions in thin Glass, or in Sope-water, or any other more transparent
+and glutinous liquor; for in these I have observ'd, _Red, Yellow, Green,
+Blue, Purple; Red, Yellow, Green, Blue, Purple; Red, Yellow, Green, Blue,
+Purple; Red, Yellow, &c._ to succeed each other, ten or twelve times, but
+in the other more _opacous_ bodies the consecutions will not be half so
+many.
+
+And therefore secondly, the _laminated_ body must be transparent, and this
+I argue from this, that I have not been able to produce any colour at all
+with an _opacous_ body, though never so thin. And this I have often try'd,
+by pressing small _Globule_ of _Mercury_ between two smooth Plates of
+Glass, whereby I have reduc'd that body to a much greater thinness then was
+requisite to exhibit the colours with a transparent body.
+
+Thirdly, there must be a considerable reflecting body adjacent to the under
+or further side of the _lamina_ or _plate_: for this I always found, that
+the greater that reflection was, the more vivid were the appearing colours.
+
+From which Observations, is most evident, that the reflection from the
+under or further side of the body is the principal cause of the production
+of these colours; which, that it is so, and how it conduces to that effect,
+I shall further explain in the following Figure, which is here described of
+a very great thickness, as if it had been view'd through the _Microscope_;
+and 'tis indeed much thicker than any _Microscope_ (I have yet us'd) has
+been able to shew me those colour'd plates of Glass, or _Muscovie-glass_,
+which I have not without much trouble view'd with it, for though I have
+endeavoured to magnifie them as much as the Glasses were capable of, yet
+are they so exceeding thin, that I have not hitherto been able positively
+to determine their thickness. This Figure therefore I here represent, is
+wholy _Hypothetical_.
+
+Let ABCDHFE in the sixth Figure be a _frustum_ of _Muscovy-glass_, thinner
+toward the end AE, and thicker towards DF. Let us first suppose the Ray
+aghb coming from the Sun, of some remote luminous object to fall
+_obliquely_ on the thinner plate BAE, part therefore is reflected back by
+cghd, the first _Superficies_; whereby the perpendicular pulse ab is after
+reflexion propagated by cd, cd, equally remote from each other with ab, ab,
+so that ag + gc, or bh + hd are either of them equal to aa, as is also cc,
+but the body BAE being transparent, a part of the light of this Ray is
+refracted in the surface AB, and propagated by gikh to the surface EF,
+whence it is reflected and refracted again by the surface AB. So that after
+two refractions and one reflection, there is propagated a kind of fainter
+Ray emnf, whose pulse is not only weaker by reason of the two refractions
+in the surface AB, but by reason of the time spent in passing and repassing
+between the two surfaces AB and EF, ef which is this fainter or weaker
+pulse comes behind the pulse cd; so that hereby (the surfaces AB, and EF
+being so neer together, that the eye cannot _discriminate_ them from one)
+this confus'd or _duplicated_ pulse, whose strongest part precedes, and
+whose weakest follows, does produce on the _Retina_, (or the _optick nerve_
+that covers the bottom of the eye) the sensation of a _Yellow_.
+
+And secondly, this _Yellow_ will appear so much the deeper, by how much the
+further back towards the middle between cd and cd the spurious pulse ef is
+remov'd, as in 2 where the surface BC being further remov'd from EF, the
+weaker pulse ef will be nearer to the middle, and will make an impression
+on the eye of a _Red_.
+
+But thirdly, if the two reflecting surfaces be yet further remov'd asunder
+(as in 3 CD and EF are) then will the weaker pulse be so farr behind, that
+it will be more then half the distance between cd and cd. And in this case
+it will rather seem to precede the following stronger pulse, then to follow
+the preceding one, and consequently a _Blue_ will be generated. And when
+the weaker pulse is just in the middle between two strong ones, then is a
+deep and lovely _Purple_ generated; but when the weaker pulse ef is very
+neer to cd, then is there generated a _Green_, which will be _bluer_, or
+_yellower_, according as the _approximate_ weak pulse does precede or
+follow the stronger.
+
+Now fourthly, if the thicker Plate chance to be cleft into two thinner
+Plates, as CDFE is divided into two Plates by the surface GH then from the
+composition arising from the three reflections in the surfaces CD, GH, and
+EF, there will be generated several compounded or mixt colours, which will
+be very differing, according as the proportion between the thicknesses of
+those two divided Plates CDHG, and GHFE are varied.
+
+And _fifthly_, if these surfaces CD and FE are further remov'd asunder, the
+weaker pulse will yet lagg behind much further, and not onely be
+_coincident_ with the second, cd, but lagg behind that also, and that so
+much the more, by how much the thicker the Plate be; so that by degrees it
+will be _coincident_ with the third cd backward also, and by degrees, as
+the Plate grows thicker with a fourth, and so onward to a fifth, sixth,
+seventh, or eighth; so that if there be a thin transparent body, that from
+the greatest thinness requisite to produce colours, does, in the manner of
+a Wedge, by degrees grow to the greatest thickness that a Plate can be of,
+to exhibit a colour by the reflection of Light from such a body, there
+shall be generated several consecutions of colours, whose order from the
+thin end towards the thick, shall be _Yellow, Red, Purple, Blue, Green;
+Yellow, Red, Purple, Blue, Green; Yellow, Red, Purple, Blue, Green;
+Yellow_, &c. and these so often repeated, as the weaker pulse does lose
+paces with its _Primary_, or first pulse, and is _coincident_ with a
+second, third, fourth, fifth, sixth, &c. pulse behind the first. And this,
+as it is _coincident_, or follows from the first _Hypothesis_ I took of
+colours, so upon experiment have I found it in multitudes of instances that
+seem to prove it. One thing which seems of the greatest concern in this
+_Hypothesis_, is to determine the greatest or least thickness requisite for
+these effects, which, though I have not been wanting in attempting, yet so
+exceeding thin are these coloured Plates, and so imperfect our
+_Microscope_, that I have not been hitherto successfull, though if my
+endeavours shall answer my expectations, I shall hope to gratifie the
+curious Reader with some things more remov'd beyond our reach hitherto.
+
+Thus have I, with as much brevity as I was able, endeavoured to explicate
+(_Hypothetically_ at least) the causes of the _Phænomena_ I formerly
+recited, on the consideration of which I have been the more particular.
+
+First, because I think these I have newly given are capable of explicating
+all the _Phænomena_ of colours, not onely of those appearing in the
+_Prisme_, Water-drop, or Rainbow, and in _laminated_ or plated bodies, but
+of all that are in the world, whether they be fluid or solid bodies,
+whether in thick or thin, whether transparent, or seemingly opacous, as I
+shall in the next Observation further endeavour to shew. And secondly,
+because this being one of the two ornaments of all bodies discoverable by
+the sight, whether looked on with, or without a _Microscope_, it seem'd to
+deserve (somewhere in this Tract, which contains a description of the
+Figure and Colour of some minute bodies) to be somewhat the more intimately
+enquir'd into.
+
+       *       *       *       *       *
+
+
+Observ. X. _Of _Metalline_, and other real Colours._
+
+Having in the former Discourse, from the Fundamental cause of Colour, made
+it probable, that there are but two Colours, and shewn, that the _Phantasm_
+of Colour is caus'd by the sensation of the _oblique_ or uneven pulse of
+Light which is capable of no more varieties than two that arise from the
+two sides of the _oblique_ pulse, though each of those be capable of
+infinite gradations or degrees (each of them beginning from _White_, and
+ending the one in the deepest _Scarlet_ or _Yellow_, the other in the
+deepest _Blue_) I shall in this _Section_ set down some Observations which
+I have made of other colours, such as _Metalline_ powders tinging or
+colour'd bodies and several kinds of tinctures or ting'd liquors, all
+which, together with those I treated of in the former Observation will, I
+suppose, comprise the several subjects in which colour is observ'd to be
+inherent, and the several manners by which it _inheres_, or is apparent in
+them. And here I shall endeavour to shew by what composition all kind of
+compound colours are made, and how there is no colour in the world but may
+be made from the various degrees of these two colours, together with the
+intermixtures of _Black_ and _White_.
+
+And this being so, as I shall anon shew, it seems an evident argument to
+me, that all colours whatsoever, whether in fluid or solid, whether in very
+transparent or seemingly _opacous_, have the same efficient cause, to wit,
+some kind of _refraction_ whereby the Rays that proceed from such bodies,
+have their pulse _obliquated_ or confus'd in the manner I explicated in the
+former _Section_; that is, a _Red_ is caus'd by a duplicated or confus'd
+pulse, whose strongest pulse precedes, and a weaker follows: and a _Blue_
+is caus'd by a confus'd pulse, where the weaker pulse precedes, and the
+stronger follows. And according as these are, more or less, or variously
+mixt and compounded, so are the _sensations_, and consequently the
+_phantasms_ of colours _diversified_.
+
+To proceed therefore; I suppose, that all transparent colour'd bodies,
+whether fluid or solid, do consist at least of two parts, or two kinds of
+substances, the one of a substance of a somewhat differing _refraction_
+from the other. That one of these substances which may be call'd the
+_tinging_ substance, does consist of distinct parts, or particles of a
+determinate bigness which are _disseminated_, or dispers'd all over the
+other: That these particles, if the body be equally and uniformly colour'd,
+are evenly rang'd and dispers'd over the other contiguous body; That where
+the body is deepest ting'd, there these particles are rang'd thickest, and
+where 'tis but faintly ting'd, they are rang'd much thinner, but uniformly.
+That by the mixture of another body that unites with either of these, which
+has a differing refraction from either of the other, quite differing
+effects will be produc'd, that is, the _consecutions_ of the confus'd
+pulses will be much of another kind, and consequently produce other
+_sensations_ and _phantasms_ of colours, and from a _Red_ may turn to a
+_Blue_, or from a _Blue_ to a _Red_, &c.
+
+Now, that this may be the better understood, I shall endeavour to explain
+my meaning a little more sensible by a _Scheme_: Suppose we therefore in
+the seventh _Figure_ of the sixth _Scheme_, that ABCD represents a Vessel
+holding a ting'd liquor, let IIIII, &c. be the clear liquor, and let the
+tinging body that is mixt with it be EE, &c. FF, &c. GG, &c. HH, &c. whose
+particles (whether round, or some other determinate Figure is little to our
+purpose) are first of a determinate and equal bulk. Next, they are rang'd
+into the form of _Quincunx_, or _Equilaterotriangular_ order, which that
+probably they are so, and why they are so, I shall elsewhere endeavour to
+shew. Thirdly, they are of such a nature, as does either more easily or
+more difficultly transmit the Rays of light then the liquor; if more
+easily, a _Blue_ is generated, and if more difficultly, a _Red_ or
+_Scarlet_.
+
+And first, let us suppose the tinging particles to be of a substance that
+does more _impede_ the Rays of light, we shall find that the pulse or wave
+of light mov'd from AD to BC, will proceed on, through the containing
+_medium_ by the pulses or waves KK, LL, MM, NN, OO; but because several of
+these Rays that go to the constitution of these pulses will be slugged or
+stopped by the tinging particles E, F, G, H; therefore there shall be
+_secundary_ and weak pulse that shall follow the Ray, namely PP which will
+be the weaker: first, because it has suffer'd many refractions in the
+impeding body; next, for that the Rays will be a little dispers'd or
+confus'd by reason of the refraction in each of the particles, whether
+_round_ or _angular_; and this will be more evident, if we a little more
+closely examine any one particular tinging _Globule_.
+
+Suppose we therefore AB in the eighth _Figure_ of the sixth _Scheme_, to
+represent a tinging _Globule_ or particle which has a greater refraction
+than the liquor in which it is contain'd: Let CD be a part of the pulse of
+light which is _propagated_ through the containing _medium_; this pulse
+will be a little stopt or impeded by the _Globule_, and so by that time the
+pulse is past to EF that part of it which has been impeded by passing
+through the _Globule_, will get but to LM, and so that pulse which has been
+_propagated_ through the _Globule_, to wit, LM, NO, PQ, will always come
+behind the pulses EF, GH, IK, &c.
+
+Next, by reason of the greater impediment in AB, and its _Globular_ Figure,
+the Rays that pass through it will be dispers'd, and very much scatter'd.
+Whence CA and DB which before went _direct_ and _parallel_, will after the
+refraction in AB, _diverge_ and spread by AP, and BQ; so that as the Rays
+do meet with more and more of these tinging particles in their way, by so
+much the more will the pulse of light further lagg behind the clearer
+pulse, or that which has fewer refractions, and thence the deeper will the
+colour be, and the fainter the light that is trajected through it; for not
+onely many Rays are reflected from the surfaces of AB, but those Rays that
+get through it are very much disordered.
+
+By this _Hypothesis_ there is no one experiment of colour that I have yet
+met with, but may be, I conceive, very rationably solv'd, and perhaps, had
+I time to examine several particulars requisite to the demonstration of it,
+I might prove it more than probable, for all the experiments about the
+changes and mixings of colours related in the Treatise of Colours,
+published by the _Incomparable_ Mr. _Boyle_, and multitudes of others which
+I have observ'd, do so easily and naturally flow from those principles,
+that I am very apt to think it probable, that they own their production to
+no other _secundary_ cause: As to instance in two or three experiments. In
+the twentieth Experiment, this _Noble Authour_ has shewn that the deep
+_bluish purple-colour_ of _Violets_, may be turn'd into a _Green_, by
+_Alcalizate Salts_, and to a _Red_ by acid; that is, a _Purple_ consists of
+two colours, a deep _Red_, and a deep _Blue_; when the _Blue_ is diluted,
+or altered, or destroy'd by _acid Salts_, the _Red_ becomes predominant,
+but when the _Red_ is diluted by _Alcalizate_, and the _Blue_ heightned,
+there is generated a _Green_; for of a _Red_ diluted, is made a _Yellow_,
+and _Yellow_ and _Blue_ make a _Green_.
+
+Now, because the _spurious_ pulses which cause a _Red_ and a _Blue_, do the
+one follow the clear pulse, and the other precede it, it usually follows,
+that those _Saline_ refracting bodies which do _dilute_ the colour of the
+one, do deepen that of the other. And this will be made manifest by almost
+all kinds of _Purples_, and many sorts of _Greens_, both these colours
+consisting of mixt colours; for if we suppose A and A in the ninth Figure,
+to represent two pulses of clear light, which follow each other at a
+convenient distance, AA, each of which has a _spurious_ pulse preceding it,
+as BB, which makes a _Blue_, and another following it, as CC, which makes a
+_Red_, the one caus'd by tinging particles that have a greater refraction,
+the other by others that have a less refracting quality then the liquor or
+_Menstruum_ in which these are dissolv'd, whatsoever liquor does so alter
+the refraction of the one, without altering that of the other part of the
+ting'd liquor, must needs very much alter the colour of the liquor; for if
+the refraction of the _dissolvent_ be increas'd, and the refraction of the
+tinging particles not altered, then will the preceding _spurious_ pulse be
+shortned or stopt, and not out-run the clear pulse so much; so that BB will
+become EE, and the _Blue_ be _diluted_, whereas the other _spurious_ pulse
+which follows will be made to lagg much more, and be further behind AA than
+before, and CC will become _ff_, and so the _Yellow_ or _Red_ will be
+heightned.
+
+A _Saline_ liquor therefore, mixt with another ting'd liquor, may alter the
+colour of it several ways, either by altering the refraction of the liquor
+in which the colour swims: or secondly by varying the refraction of the
+coloured particles, by uniting more intimately either with some particular
+_corpuscles_ of the tinging body, or with all of them, according as it has
+a _congruity_ to some more especially, or to all alike: or thirdly, by
+uniting and interweaving it self with some other body that is already
+joyn'd with the tinging particles, with which substance it may have a
+_congruity_, though it have very little with the particles themselves: or
+fourthly, it may alter the colour of a ting'd liquor by dis-joyning certain
+particles which were before united with the tinging particles, which though
+they were somewhat _congruous_ to these particles, have yet a greater
+_congruity_ with the newly _infus'd Saline menstruum_. It may likewise
+alter the colour by further dissolving the tinging substance into smaller
+and smaller _particles_, and so _diluting_ the colour; or by uniting
+several _particles_ together as in precipitations, and so deepning it, and
+some such other ways, which many experiments and comparisons of differing
+trials together, might easily inform one of.
+
+From these Principles applied, may be made out all the varieties of colours
+observable, either in liquors, or any other ting'd bodies, with great ease,
+and I hope intelligible enough, there being nothing in the _notion_ of
+colour, or in the suppos'd production, but is very conceivable, and may be
+possible.
+
+The greatest difficulty that I find against this _Hypothesis_, is, that
+there seem to be more distinct colours then two, that is, then Yellow and
+Blue. This Objection is grounded on this reason, that there are several
+Reds, which _diluted_, make not a Saffron or pale Yellow, and therefore
+Red, or Scarlet seems to be a third colour distinct from a deep degree of
+Yellow.
+
+To which I answer, that Saffron affords us a deep Scarlet tincture, which
+may be _diluted_ into as pale a Yellow as any, either by making a weak
+solution of the Saffron, by infusing a small parcel of it into a great
+quantity of liquor, as in spirit of Wine, or else by looking through a very
+thin quantity of the tincture, and which may be heightn'd into the
+loveliest Scarlet, by looking through a very thick body of this tincture,
+or through a thinner parcel of it, which is highly _impregnated_ with the
+tinging body, by having had a greater quantity of the Saffron dissolv'd in
+a smaller parcel of the liquor.
+
+Now, though there may be some particles of other tinging bodies that give a
+lovely Scarlet also, which though _diluted_ never so much with liquor, or
+looked on through never so thin a parcel of ting'd liquor, will not yet
+afford a pale Yellow, but onely a kind of faint Red; yet this is no
+argument but that those ting'd particles may have in them the faintest
+degree of Yellow, though we may be unable to make them exhibit it; For that
+power of being _diluted_ depending upon the divisibility of the ting'd
+body, if I am unable to make the tinging particles so thin as to exhibit
+that colour, it does not therefore follow, that the thing is impossible to
+be done; now, the tinging particles of some bodies are of such a nature,
+that unless there be found some way of comminuting them into less bulks
+then the liquor does dissolve them into, all the Rays that pass through
+them must necessarily receive a tincture so deep, as their appropriate
+refractions and bulks compar'd with the proprieties of the dissolving
+liquor must necessarily dispose them to empress, which may perhaps be a
+pretty deep Yellow, or pale Red.
+
+And that this is not _gratis dictum_, I shall add one instance of this
+kind, wherein the thing is most manifest.
+
+If you take Blue _Smalt_, you shall find, that to afford the deepest Blue,
+which _cæteris paribus_ has the greatest particles or sands; and if you
+further divide, or grind those particles on a Grindstone, or _porphyry_
+stone, you may by _comminuting_ the sands of it, _dilute_ the Blue into as
+pale a one as you please, which you cannot do by laying the colour thin;
+for wheresoever any single particle is, it exhibits as deep a Blue as the
+whole mass. Now, there are other Blues, which though never so much ground,
+will not be _diluted_ by grinding, because consisting of very small
+particles, very deeply ting'd, they cannot by grinding be actually
+separated into smaller particles then the operation of the fire, or some
+other dissolving _menstruum_, reduc'd them to already.
+
+Thus all kind of _Metalline_ colours, whether _precipitated_, _sublim'd_,
+_calcin'd_, or otherwise prepar'd, are hardly chang'd by grinding, as
+_ultra marine_ is not more _diluted_; nor is _Vermilion_ or _Red-lead_ made
+of a more faint colour by grinding; for the smallest particles of these
+which I have view'd with my greatest Magnifying-Glass, if they be well
+enlightned, appear very deeply ting'd with their peculiar colours; nor,
+though I have magnified and enlightned the particles exceedingly, could I
+in many of them, perceive them to be transparent, or to be whole particles,
+but the smallest specks that I could find among well ground _Vermilion_ and
+_Red-lead_, seem'd to be a Red mass, compounded of a multitude of less and
+less motes, which sticking together, compos'd a bulk, not one thousand
+thousandth part of the smallest visible sand or mote.
+
+And this I find generally in most _Metalline_ colours, that though they
+consist of parts so exceedingly small, yet are they very deeply ting'd,
+they being so ponderous, and having such a multitude of terrestrial
+particles throng'd into a little room; so that 'tis difficult to find any
+particle transparent or resembling a pretious stone, though not impossible;
+for I have observ'd divers such shining and resplendent colours intermixt
+with the particles of _Cinnaber_, both natural and artificial, before it
+hath been ground and broken or flaw'd into _Vermilion_: As I have also in
+_Orpiment_, _Red-lead_, and _Bise_, which makes me suppose, that those
+_metalline_ colours are by grinding, not onely broken and separated
+actually into smaller pieces, but that they are also flaw'd and brused,
+whence they, for the most part, become _opacous_, like flaw'd Crystal or
+Glass, &c. But for _Smalts_ and _verditures_, I have been able with a
+_Microscope_ to perceive their particles very many of them transparent.
+
+Now, that the others also may be transparent, though they do not appear so
+to the _Microscope_, may be made probable by this Experiment: that if you
+take _ammel_ that is almost _opacous_, and grind it very well on a
+_Porphyry_, or _Serpentine_, the small particles will by reason of their
+flaws, appear perfectly _opacous_; and that 'tis the flaws that produce
+this _opacousness_, may be argued from this, that particles of the same
+_Ammel_ much thicker if unflaw'd will appear somewhat transparent even to
+the eye; and from this also, that the most transparent and clear Crystal,
+if heated in the fire, and then suddenly quenched, so that it be all over
+flaw'd, will appear _opacous_ and white.
+
+And that the particles of _Metalline_ colours are transparent, may be
+argued yet further from this, that the Crystals, or _Vitriols_ of all
+Metals, are transparent, which since they consist of _metalline_ as well as
+_saline_ particles, those _metalline_ ones must be transparent, which is
+yet further confirm'd from this, that they have for the most part,
+_appropriate_ colours; so the _vitriol_ of Gold is Yellow; of Copper, Blue,
+and sometimes Green; of Iron, green; of Tinn and Lead, a pale White; of
+Silver, a pale Blue, _&._
+
+And next, the _Solution_ of all Metals into _menstruums_ are much the same
+with the _Vitriols_, or Crystals. It seems therefore very probable, that
+those colours which are made by the _precipitation_ of those particles out
+of the _menstruums_ by transparent _precipitating_ liquors should be
+transparent also. Thus Gold _precipitates_ with _oyl of Tartar_, or _spirit
+of Urine_ into a brown Yellow, Copper with spirit of _Urine_ into a Mucous
+blue, which retains its transparency. A solution of sublimate (as the same
+Illustrious Authour I lately mention'd shews in his 40. Experiment)
+_precipitates_ with oyl of _Tartar_ _per deliquium_, into an Orange
+colour'd _precipitate_; nor is it less probable, that the _calcination_ of
+those _Vitriols_ by the fire, should have their particles transparent: Thus
+_Saccarum Saturni_, or the _Vitriol of Lead_ by _calcination_ becomes a
+deep Orange-colour'd _minium_, which is a kind of _precipitation_ by some
+Salt which proceeds from the fire; common _Vitriol_ _calcin'd_, yields a
+deep Brown Red, etc.
+
+A third Argument, that the particles of Metals are transparent, is, that
+being _calcin'd_, and melted with Glass, they tinge the Glass with
+transparent colours. Thus the _Calx_ of Silver tinges the Glass on which it
+is anneal'd with a lovely Yellow, or Gold colour, &c.
+
+And that the parts of Metals are transparent, may be farther argued from
+the transparency of Leaf-gold, which held against the light, both to the
+naked eye, and the _Microscope,_ exhibits a deep Green. And though I have
+never seen the other Metals _laminated_ so thin, that I was able to
+perceive them transparent, yet, for Copper and Brass, if we had the same
+conveniency for _laminating_ them, as we have for Gold, we might, perhaps,
+through such plates or leaves, find very differing degrees of Blue, or
+Green; for it seems very probable, that those Rays that rebound from them
+ting'd, with a deep Yellow, or pale Red, as from Copper, or with a pale
+Yellow, as from Brass, have past through them; for I cannot conceive how by
+reflection alone those Rays can receive a tincture, taking any _Hypothesis_
+extant.
+
+So that we see there may a sufficient reason be drawn from these instances,
+why those colours which we are unable to _dilute_ to the palest Yellow, or
+Blue, or Green, are not therefore to be concluded not to be a deeper degree
+of them; for supposing we had a great company of small _Globular_ essence
+Bottles, or round Glass bubbles, about the bigness of a Walnut, fill'd each
+of them with a very deep mixture of Saffron, and that every one of them did
+appear of a deep Scarlet colour, and all of them together did _exhibit_ at
+a distance, a deep dy'd Scarlet body. It does not follow, because after we
+have come nearer to this _congeries_, or mass, and divided it into its
+parts, and examining each of its parts severally or apart, we find them to
+have much the same colour with the whole mats; it does not, I say,
+therefore follow, that if we could break those _Globules_ smaller, or any
+other ways come to see a smaller or thinner parcel of the ting'd liquor
+that fill'd those bubbles, that that ting'd liquor must always appear Red,
+or of a Scarlet hue, since if Experiment be made, the quite contrary will
+ensue; for it is capable of being _diluted_ into the palest Yellow.
+
+Now, that I might avoid all the Objections of this kind, by exhibiting an
+Experiment that might by ocular proof convince those whom other reasons
+would not prevail with, I provided me a _Prismatical Glass_, made hollow,
+just in the form of a Wedge, such as is represented in the tenth _Figure_
+of the sixth _Scheme_. The two _parallelogram_ sides ABCD, ABEF, which met
+at a point, were made of the clearest Looking-glass plates well ground and
+polish'd that I could get; these were joyn'd with hard cement to the
+_triangular_ sides, BCE, ADF, which were of Wood; the _Parallelogram_ base
+BCEF, likewise was of Wood joyn'd on to the rest with hard cement, and the
+whole _Prismatical_ Box was exactly stopt every where, but onely a little
+hole near the base was left, whereby the Vessel could be fill'd with any
+liquor, or emptied again at pleasure.
+
+One of these Boxes (for I had two of them) I fill'd with a pretty deep
+tincture of _Aloes_, drawn onely with fair Water, and then stopt the hole
+with a piece of Wax, then, by holding this Wedge against the Light, and
+looking through it, it was obvious enough to see the tincture of the liquor
+near the edge of the Wedge where it was but very thin, to be a pale but
+well colour'd Yellow, and further and further from the edge, as the liquor
+grew thicker and thicker, this tincture appear'd deeper and deeper, so that
+near the blunt end, which was seven Inches from the edge and three Inches
+and an half thick; it was of a deep and well colour'd Red. Now, the clearer
+and purer this tincture be, the more lovely will the deep Scarlet be, and
+the fouler the tincture be, the more dirty will the Red appear; so that
+some dirty tinctures have afforded their deepest Red much of the colour of
+burnt Oker or _Spanish_ brown; others as lovely a colour as _Vermilion_,
+and some much brighter; but several others, according as the tinctures were
+worse or more foul, exhibited various kinds of Reds, of very differing
+degrees.
+
+The other of these Wedges, I fill'd with a most lovely tincture of Copper,
+drawn from the filings of it, with spirit of _Urine_, and this Wedge held
+as the former against the Light, afforded all manner of Blues, from the
+faintest to the deepest, so that I was in good hope by these two, to have
+produc'd all the varieties of colours imaginable; for I thought by this
+means to have been able by placing the two _Parallelogram_ sides together,
+and the edges contrary ways, to have so mov'd them to and fro one by
+another, as by looking through them in several places, and through several
+thicknesses, I should have compounded, and consequently have seen all those
+colours, which by other like compositions of colours would have ensued.
+
+But insteed of meeting with what I look'd for, I met with somewhat more
+admirable; and that was, that I found my self utterly unable to see through
+them when placed both together, though they were transparent enough when
+asunder; and though I could see through twice the thickness, when both of
+them were fill'd with the same colour'd liquors, whether both with the
+Yellow, or both with the Blue, yet when one was fill'd with the Yellow, the
+other with the Blue, and both looked through, they both appear'd dark,
+onely when the parts near the tops were look'd through, they exhibited
+Greens, and those of very great variety, as I expected, but the Purples and
+other colours, I could not by any means make, whether I endeavour'd to look
+through them both against the Sun, or whether I plac'd them against the
+hole of a darkned room.
+
+But notwithstanding this mis-ghessing, I proceeded on with my trial in a
+dark room, and having two holes near one another, I was able, by placing my
+Wedges against them, to mix the ting'd Rays that past through them, and
+fell on a sheet of white Paper held at a convenient distance from them as I
+pleas'd; so that I could make the Paper appear of what colour I would, by
+varying the thicknesses of the Wedges, and consequently the tincture of the
+Rays that past through the two holes, and sometimes also by varying the
+Paper, that is, insteed of a white Paper, holding a gray, or a black piece
+of Paper.
+
+Whence I experimentally found what I had before imagin'd, that all the
+varieties of colours imaginable are produc'd from several degrees of these
+two colours, namely, Yellow and Blue, or the mixture of them with light and
+darkness, that is, white and black. And all those almost infinite varieties
+which Limners and Painters are able to make by compounding those several
+colours they lay on their Shels or _Palads_, are nothing else, but some
+_compositum_, made up of some one or more, or all of these four.
+
+Now, whereas it may here again be objected, that neither can the Reds be
+made out of the Yellows, added together, or laid on in greater or less
+quantity, nor can the Yellows be made out of the Reds though laid never so
+thin; and as for the addition of White or Black, they do nothing but either
+whiten or darken the colours to which they are added, and not at all make
+them of any other kind of colour: as for instance, _Vermilion_, by being
+temper'd with White Lead, does not at all grow more Yellow, but onely there
+is made a whiter kind of Red. Nor does Yellow _Oker_, though laid never so
+thick, produce the colour of _Vermilion_, nor though it be temper'd with
+Black, does it at all make a Red; nay, though it be temper'd with White, it
+will not afford a fainter kind of Yellow, such as _masticut_, but onely a
+whiten'd Yellow; nor will the Blues be _diluted_ or deepned after the
+manner I speak of, as _Indico_ will never afford so fine a Blue as
+_Ultramarine_ or _Bise_; nor will it, temper'd with _Vermilion_, ever
+afford a Green, though each of them be never so much temper'd with white.
+
+To which I answer, that there is a great difference between _diluting_ a
+colour and whitening of it; for _diluting_ a colour, is to make the
+colour'd parts more thin, so that the ting'd light, which is made by
+trajecting those ting'd bodies, does not receive so deep a tincture; but
+whitening a colour is onely an intermixing of many clear reflections of
+light among the same ting'd parts; deepning also, and darkning or blacking
+a colour, are very different; for deepning a colour, is to make the light
+pass through a greater quantity of the same tinging body; and darkning or
+blacking a colour, is onely interposing a multitude of dark or black spots
+among the same ting'd parts, or placing the colour in a more faint light.
+
+First therefore, as to the former of these operations, that is, diluting
+and deepning, most of the colours us'd by the Limners and Painters are
+incapable of, to wit, _Vermilion_ and _Red-lead_, and _Oker_, because the
+ting'd parts are so exceeding small, that the most curious Grindstones we
+have, are not able to separate them into parts actually divided so small as
+the ting'd particles are; for looking on the most curiously ground
+_Vermilion_, and _Oker_, and _Red-lead_, I could perceive that even those
+small _corpuscles_ of the bodies they left were compounded of many pieces,
+that is, they seem'd to be small pieces compounded of a multitude of lesser
+ting'd parts: each piece seeming almost like a piece of Red Glass, or
+ting'd Crystal all flaw'd; so that unless the Grindstone could actually
+divide them into smaller pieces then those flaw'd particles were, which
+compounded that ting'd mote I could see with my _Microscope_, it would be
+impossible to _dilute_ the colour by grinding, which, because the finest we
+have will not reach to do in _Vermilion_ or _Oker_, therefore they cannot
+at all, or very hardly be _diluted_.
+
+Other colours indeed, whose ting'd particles are such as may be made
+smaller, by grinding their colour, may be _diluted_. Thus several of the
+Blues may be _diluted_, as _Smalt_ and _Bise_; and _Masticut_, which is
+Yellow, may be made more faint: And even _Vermilion_ it self may, by too
+much grinding, be brought to the colour of _Red-lead_, which is but an
+Orange colour, which is confest by all to be very much upon the Yellow.
+Now, though perhaps somewhat of this _diluting_ of _Vermilion_ by overmuch
+grinding may be attributed to the Grindstone, or muller, for that some of
+their parts may be worn off and mixt with the colour, yet there seems not
+very much, for I have done it on a Serpentine-stone with a muller made of a
+Pebble, and yet observ'd the same effect follow.
+
+And secondly, as to the other of these operations on colours, that is, the
+deepning of them, Limners and Painters colours are for the most part also
+uncapable. For they being for the most part _opacous_; and that
+_opacousness_, as I said before, proceeding from the particles, being very
+much flaw'd, unless we were able to joyn and re-unite those flaw'd
+particles again into one piece, we shall not be able to deepen the colour,
+which since we are unable to do with most of the colours which are by
+Painters accounted _opacous_, we are therefore unable to deepen them by
+adding more of the same kind.
+
+But because all those _opacous_ colours have two kinds of beams or Rays
+reflected from them, that is, Rays unting'd, which are onely reflected from
+the outward surface, without at all penetrating of the body, and ting'd
+Rays which are reflected from the inward surfaces or flaws after they have
+suffer'd a two-fold refraction; and because that transparent liquors mixt
+with such _corpuscles_, do, for the most part, take off the former kind of
+reflection; therefore these colours mixt with Water or Oyl, appear much
+deeper than when dry, for most part of that white reflection from the
+outward surface is remov'd. Nay, some of these colours are very much
+deepned by the mixture with some transparent liquor, and that because they
+may perhaps get between those two flaws, and so consequently joyn two or
+more of those flaw'd pieces together; but this happens but in a very few.
+
+Now, to shew that all this is not _gratis dictum_, I shall set down some
+Experiments which do manifest these things to be probable and likely, which
+I have here deliver'd.
+
+For, first, if you take any ting'd liquor whatsoever, especially if it be
+pretty deeply ting'd, and by any means work it into a froth, the
+_congeries_ of that froth shall seem an _opacous_ body, and appear of the
+same colour, but much whiter than that of the liquor out of which it is
+made. For the abundance of reflections of the Rays against those surfaces
+of the bubbles of which the froth consists, does so often rebound the Rays
+backwards, that little or no light can pass through, and consequently the
+froth appears _opacous_.
+
+Again, if to any of these ting'd liquors that will endure the boiling there
+be added a small quantity of fine flower (the parts of which through the
+_Microscope_ are plainly enough to be perceiv'd to consist of transparent
+_corpuscles_) and suffer'd to boyl till it thicken the liquor, the mass of
+the liquor will appear _opacous_, and ting'd with the same colour, but very
+much whiten'd.
+
+Thus, if you take a piece of transparent Glass that is well colour'd, and
+by heating it, and then quenching it in Water, you flaw it all over, it
+will become _opacous_, and will exhibit the same colour with which the
+piece is ting'd, but fainter and whiter.
+
+Or, if you take a Pipe of this transparent Glass, and in the flame of a
+Lamp melt it, and then blow it into very thin bubbles, then break those
+bubbles, and collect a good parcel of those _laminæ_ together in a Paper,
+you shall find that a small thickness of those Plates will constitute an
+_opacous_ body, and that you may see through the mass of Glass before it be
+thus _laminated_, above four times the thickness: And besides, they will
+now afford a colour by reflection as other _opacous_ (as they are call'd)
+colours will, but much fainter and whiter than that of the Lump or Pipe out
+of which they were made.
+
+Thus also, if you take _Putty_, and melt it with any transparent colour'd
+Glass, it will make it become an _opacous_ colour'd lump, and to yield a
+paler and whiter colour than the lump by reflection.
+
+The same thing may be done by a preparation of _Antimony_, as has been
+shewn by the Learned _Physician_, Dr. _C.M._ in his Excellent Observations
+and Notes on _Nery's Art of Glass_; and by this means all transparent
+colours become _opacous_, or _ammels_. And though by being ground they lose
+very much of their colour, growing much whiter by reason of the multitude
+of single reflections from their outward surface, as I shew'd afore, yet
+the fire that in the nealing or melting re-unites them, and so renews those
+_spurious_ reflections, removes also those whitenings of the colour that
+proceed from them.
+
+As for the other colours which Painters use, which are transparent, and
+us'd to varnish over all other paintings, 'tis well enough known that the
+laying on of them thinner or thicker, does very much _dilute_ or deepen
+their colour.
+
+Painters Colours therefore consisting most of them of solid particles, so
+small that they cannot be either re-united into thicker particles by any
+Art yet known, and consequently cannot be deepned; or divided into
+particles so small as the flaw'd particles that exhibit that colour, much
+less into smaller, and consequently cannot be _diluted_; It is necessary
+that they which are to imitate all kinds of colours, should have as many
+degrees of each colour as can be procur'd.
+
+And to this purpose, both Limners and Painters have a very great variety
+both of Yellows and Blues, besides several other colour'd bodies that
+exhibit very compounded colours, such as Greens and Purples; and others
+that are compounded of several degrees of Yellow, or several degrees of
+Blue, sometimes unmixt, and sometimes compounded with several other
+colour'd bodies.
+
+The Yellows, from the palest to the deepest Red or Scarlet, which has no
+intermixture of Blue, are _pale and deep Masticut, Orpament, English Oker,
+brown Oker, Red Lead, and Vermilion, burnt English Oker, and burnt brown
+Oker,_ which last have a mixture of dark or dirty parts with them, &c.
+
+Their Blues are several kinds of _Smalts_, and _Verditures_, and _Bise_,
+and _Ultramarine_, and _Indico_, which last has many dirty or dark parts
+intermixt with it.
+
+Their compounded colour'd bodies, as _Pink_, and _Verdigrese_, which are
+Greens, the one a _Popingay_, the other a _Sea-green_; then _Lac_, which is
+a very lovely _Purple_.
+
+To which may be added their Black and White, which they also usually call
+Colours, of each of which they have several kinds, such as _Bone Black_,
+made of _Ivory_ burnt in a close Vessel, and _Blue Black_, made of the
+small coal of _Willow_, or some other Wood; and _Cullens earth_, which is a
+kind of brown Black, &c. Their usual Whites are either artificial or
+natural _White Lead_, the last of which is the best they yet have, and with
+the mixing and tempering these colours together, are they able to make an
+imitation of any colour whatsoever: Their Reds or deep Yellows, they can
+_dilute_ by mixing pale Yellows with them, and deepen their pale by mixing
+deeper with them; for it is not with _Opacous_ colours as it is with
+transparent, where by adding more Yellow to yellow, it is deepned, but in
+_opacous_ _diluted_. They can whiten any colour by mixing White with it,
+and darken any colour by mixing Black, or some dark and dirty colour. And
+in a word, most of the colours, or colour'd bodies they use in Limning and
+Painting, are such, as though mixt with any other of their colours, they
+preserve their own hue, and by being in such very smal parts dispers'd
+through the other colour'd bodies, they both, or altogether represent to
+the eye a _compositum_ of all; the eye being unable, by reason of their
+smalness, to distinguish the peculiarly colour'd particles, but receives
+them as one intire _compositum_: whereas in many of these, the _Microscope_
+very easily distinguishes each of the compounding colours distinct, and
+exhibiting its own colour.
+
+Thus have I by gently mixing _Vermilion_ and _Bise_ dry, produc'd a very
+fine Purple, or mixt colour, but looking on it with the _Microscope_, I
+could easily distinguish both the Red and the Blue particles, which did not
+at all produce the _Phantasm_ of Purple.
+
+To summ up all therefore in a word, I have not yet found any solid colour'd
+body, that I have yet examin'd, perfectly _opacous_; but those that are
+least transparent are _Metalline_ and _Mineral_ bodies, whose particles
+generally, seeming either to be very small, or very much flaw'd, appear for
+the most part _opacous_, though there are very few of them that I have
+look'd on with a _Microscope_, that have not very plainly or
+circumstantially manifested themselves transparent.
+
+And indeed, there seem to be so few bodies in the world that are _in
+minimis_ opacous, that I think one may make it a rational _Query_, Whether
+there be any body absolutely thus _opacous_? For I doubt not at all (and I
+have taken notice of very many circumstances that make me of this mind)
+that could we very much improve the _Microscope_, we might be able to see
+all those bodies very plainly transparent, which we now are fain onely to
+ghess at by circumstances. Nay, the Object Glasses we yet make use of are
+such, that they make many transparent bodies to the eye, seem _opacous_
+through them, which if we widen the Aperture a little, and cast more light
+on the objects, and not charge the Glasses so deep, will again disclose
+their transparency.
+
+Now, as for all kinds of colours that are dissolvable in Water, or other
+liquors, there is nothing so manifest, as that all those ting'd liquors are
+transparent; and many of them are capable of being _diluted_ and compounded
+or mixt with other colours, and divers of them are capable of being very
+much chang'd and heightned, and fixt with several kinds of _Saline
+menstruums_. Others of them upon compounding, destroy or vitiate each
+others colours, and _precipitate_, or otherwise very much alter each others
+tincture. In the true ordering and _diluting_, and deepning, and mixing,
+and fixing of each of which, consists one of the greatest mysteries of the
+Dyers; of which particulars, because our _Microscope_ affords us very
+little information, I shall add nothing more at present; but onely that
+with a very few tinctures order'd and mixt after certain ways, too long to
+be here set down, I have been able to make an appearance of all the various
+colours imaginable, without at all using the help of _Salts_, or _Saline
+menstruums_ to vary them.
+
+As for the mutation of Colours by _Saline menstruums_, they have already
+been so fully and excellently handled by the lately mention'd Incomparable
+_Authour_, that I can add nothing, but that of a multitude of trials that I
+made, I have found them exactly to agree with his Rules and Theories; and
+though there may be infinite instances, yet may they be reduc'd under a few
+Heads, and compris'd within a very few Rules. And generally I find, that
+_Saline menstruums_ are most operative upon those colours that are Purple,
+or have some degree of Purple in them, and upon the other colours much
+less. The _spurious_ pulses that compose which, being (as I formerly noted)
+so very neer the middle between the true ones, that a small variation
+throws them both to one side, or both to the other, and so consequently
+must make a vast mutation in the formerly appearing Colour.
+
+       *       *       *       *       *
+
+
+Observ. XI. _Of _Figures_ observ'd in small Sand._
+
+Sand generally seems to be nothing else but exceeding small Pebbles, or at
+least some very small parcels of a bigger stone; the whiter kind seems
+through the _Microscope_ to consist of small transparent pieces of some
+_pellucid_ body, each of them looking much like a piece of _Alum_, or _Salt
+Gem_; and this kind of Sand is angled for the most part irregularly,
+without any certain shape, and the _granules_ of it are for the most part
+flaw'd, through amongst many of them it is not difficult to find some that
+are perfectly _pellucid_, like a piece of clear Crystal, and divers
+likewise most curiously shap'd, much after the manner of the bigger
+_Stiriæ_ of Crystal, or like the small Diamants I observ'd in certain
+Flints, of which I shall by and by relate; which last particular seems to
+argue, that this kind of Sand is not made by the comminution of greater
+transparent Crystaline bodies, but by the _concretion_ or _coagulation_ of
+Water, or some other fluid body.
+
+There are other kinds of courser Sands, which are browner, and have their
+particles much bigger; these, view'd with a _Microscope_, seem much courser
+and more _opacous_ substances, and most of them are of some irregularly
+rounded Figures; and though they seem not so _opacous_ as to the naked eye,
+yet they seem very foul and cloudy, but neither do these want curiously
+transparent, no more than they do regularly figur'd and well colour'd
+particles, as I have often found.
+
+There are multitudes of other kinds of Sands, which in many particulars,
+plainly enough discoverable by the _Microscope_, differ both from these
+last mention'd kinds of Sands, and from one another: there seeming to be as
+great variety of Sands, as there is of Stones. And as amongst Stones some
+are call'd precious from their excellency, so also are there Sands which
+deserve the same Epithite for their beauty; for viewing a small parcel of
+_East-India_ Sand (which was given me by my highly honoured friend, Mr.
+_Daniel Colwall_) and, since that, another parcel, much of the same kind, I
+found several of them, both very transparent like precious Stones, and
+regularly figur'd like Crystal, _Cornish_ Diamants, some Rubies, &c. and
+also ting'd with very lively and deep colours, like _Rubys_, _Saphyrs_,
+_Emeralds_, &c. These kinds of granuls I have often found also in _English_
+Sand. And 'tis easie to make such a counterfeit Sand with deeply ting'd
+Glass, Enamels and Painters colours.
+
+It were endless to describe the multitudes of Figures I have met with in
+these kind of minute bodies, such as _Spherical_, _Oval_, _Pyramidal_,
+_Conical_, _Prismatical_, of each of which kinds I have taken notice.
+
+But amongst many others, I met with none more observable than this pretty
+Shell (described in the _Figure_ X. of the fifth _Scheme_) which, though as
+it was light on by chance, deserv'd to have been omitted (I being unable to
+direct any one to find the like) yet for its rarity was it not
+inconsiderable, especially upon the account of the information it may
+afford us. For by it we have a very good instance of the curiosity of
+Nature in another kind of Animals which are remov'd, by reason of their
+minuteness, beyond the reach of our eyes, so that as there are several
+sorts of Insects, as Mites, and others, so small as not yet to have had any
+names; (some of which I shall afterwards describe) and small Fishes, as
+Leeches in Vineger; and smal vegetables, as Moss, and Rose-Leave-plants;
+and small Mushroms, as mould: so are there, it seems, small Shel-fish
+likewise, Nature shewing her curiosity in every Tribe of _Animals_,
+_Vegetables_, and _Minerals_.
+
+I was trying several small and single Magnifying Glasses, and casually
+viewing a parcel of white Sand, when I perceiv'd one of the grains exactly
+shap'd and wreath'd like a Shell, but endeavouring to distinguish it with
+my naked eye, it was so very small, that I was fain again to make use of
+the Glass to find it; then, whilest I thus look'd on it, with a Pin I
+separated all the rest of the granules of Sand, and found it afterwards to
+appear to the naked eye an exceeding small white spot, no bigger than the
+point of a Pin. Afterwards I view'd it every way with a better _Microscope_
+and found it on both sides, and edge-ways, to resemble the Shell of a small
+Water-Snail with a flat spiral Shell: it had twelve wreathings, a, b, c, d,
+e, &c. all very proportionably growing one less than another toward the
+middle or center of the Shell, where there was a very small round white
+spot. I could not certainly discover whether the Shell were hollow or not,
+but it seem'd fill'd with somewhat, and 'tis probable that it might be
+_petrify'd_ as other larger Shels often are, such as are mention'd in the
+seventeenth _Observation_.
+
+       *       *       *       *       *
+
+
+Observ. XII. _Of _Gravel_ in Urine._
+
+I Have often observ'd the Sand or Gravel of Urine, which seems to be a
+_tartareous_ substance, generated out of a _saline_ and a _terrestrial_
+substance _crystalliz'd_ together, in the form of _Tartar_, sometimes
+sticking to the sides of the _Urinal_, but for the most part sinking to the
+bottom, and there lying in the form of coorse common Sand; these, through
+the _Microscope_, appear to be a company of small bodies, partly
+transparent and partly _opacous_, some White, some Yellow, some Red, others
+of more brown and duskie colours.
+
+The Figure of them is for the most part flat, in the manner of Slats or
+such like plated Stones, that is, each of them seem to be made up of
+several other thinner Plates, much like _Muscovie Glass_, or _Englsh Sparr_
+to the last of which, the white plated Gravel seems most likely; for they
+seem not onely plated like that, but their sides shap'd also into _Rhombs_,
+_Rhomboeids_, and sometimes into _Rectangles_ and _Squares_. Their bigness
+and Figure may be seen in the second _Figure_ of the seventh _Plate_, which
+represents about a dozen of them lying upon a plate ABCD, some of which, as
+a, b, c, d seem'd more regular than the rest, and e, which was a small one,
+sticking on the top of another, was a perfet _Rhomboeid_ on the top, and
+had four _Rectangular_ sides.
+
+The line E which was the the measure of the _Microscope_, is 1/32 part of
+an _English_ Inch, so that the greatest bredth of any of them, exceeded not
+1/128 part of an Inch.
+
+Putting these into several liquors, I found _oyl of Vitriol_, _Spirit of
+Urine_, and several other _Saline menstruums_ to dissolve them; and the
+first of these in less than a minute without _Ebullition_, Water, and
+several other liquors, had no sudden operation upon them. This I mention,
+because those liquors that dissolve them, first make them very white, not
+_vitiating_, but rather rectifying their Figure, and thereby make them
+afford a very pretty object for the _Microscope_.
+
+How great an advantage it would be to such as are troubled with the Stone,
+to find some _menstruum_ might dissolve them without hurting the Bladder,
+is easily imagin'd, since some _injections_ made of such bodies might
+likewise dissolve the stone, which seems much of the same nature.
+
+It may therefore, perhaps, be worthy some Physicians enquiry, whether there
+may not be something mixt with the Urine in which the Gravel or Stone lies,
+which may again make it dissolve it, the first of which seems by it's
+regular Figures to have been sometimes _Crystalliz'd_ out of it. For
+whether this _Crystallization_ be made in the manner as _Alum_, _Peter_,
+&c. are _crystallized_ out of a cooling liquor, in which, by boyling they
+have been dissolv'd; or whether it be made in the manner of _Tartarum
+Vitriolatum_, that is, by the _Coalition_ of an _acid_ and a _Sulphureous_
+substance, it seems not impossible, but that the liquor it lies in, may be
+again made a _dissolvent_ of it. But leaving these inquiries to Physicians
+or Chymists, to whom it does more properly belong, I shall proceed.
+
+       *       *       *       *       *
+
+
+Observ. XIII. _Of the small _Diamants_, or _Sparks_ in _Flints_._
+
+Chancing to break a Flint stone in pieces, I found within it a certain
+cavity all crusted over with a very pretty candied substance, some of the
+parts of which, upon changing the posture of the Stone, in respect of the
+_Incident_ light, exhibited a number of small, but very vivid reflections;
+and having made use of my _Microscope_, I could perceive the whole surface
+of that cavity to be all beset with a multitude of little _Crystaline_ or
+_Adamantine_ bodies, so curiously shap'd, that it afforded a not unpleasing
+object.
+
+Having considered those vivid _repercussions_ of light, I found them to be
+made partly from the plain external surface of these regularly figured
+bodies (which afforded the vivid reflexions) and partly to be made from
+within the somewhat _pellucid_ body, that is, from some surface of the
+body, opposite to that superficies of it which was next the eye.
+
+And because these bodies were so small, that I could not well come to make
+Experiments and Examinations of them, I provided me several small _stiriæ_
+of Crystals or Diamants, found in great quantities in _Cornwall_ and are
+therefore commonly called _Cornish Diamants_: these being very _pellucid_,
+and growing in a hollow cavity of a Rock (as I have been several times
+informed by those that have observ'd them) much after the same manner as
+these do in the Flint, and having besides their outward surface very
+regularly shap'd, retaining very near the same Figures with some of those I
+observ'd in the other, became a convenient help to me for the Examination
+of the proprieties of those kinds of bodies.
+
+And first for the Reflections, in these I found it very observable, That
+the brightest reflections of light proceeded from within the _pellucid_
+body; that is, that the Rays admitted through the _pellucid_ substance in
+their getting out on the opposite side, were by the contiguous and strong
+reflecting surface of the Air very vividly reflected, so that more Rays
+were reflected to the eye by this surface, though the Ray in entring and
+getting out of the Crystal had suffer'd a double refraction, than there
+were from the outward surface of the Glass where the Ray had suffer'd no
+reflection at all.
+
+And that this was the surface of the Air that gave so vivid a
+_re-percussion_ I try'd by this means I sunk half of a _stiria_ in Water,
+so that only Water was contiguous to the under surface, and then the
+internal reflection was so exceedingly faint, that it was scarce
+discernable. Again, I try'd to alter this vivid reflection by keeping off
+the Air, with a body not fluid, and that was by rubbing and holding my
+finger very hard against the under surface, so as in many places the pulp
+of my finger did touch the Glass, without any _interjacent_ air between,
+then observing the reflection, I found, that wheresoever my finger or skin
+toucht the surface, from that part there was no reflection, but in the
+little furrows or creases of my skin, where there remain'd little small
+lines of air, from them was return'd a very vivid reflection as before. I
+try'd further, by making the surface of very pure Quicksilver to be
+contiguous to the under surface of this _pellucid_ body, and then the
+reflection from that was so exceedingly more vivid than from the air, as
+the reflection from air was than the reflection from the Water; from all
+which trials I plainly saw, that the strong reflecting air was the cause of
+this _Phænomenon_.
+
+And this agrees very well with the _Hypothesis_ of light and _Pellucid_
+bodies which I have mention'd in the description of _Muscovy-glass_; for we
+there suppose Glass to be a _medium_, which does less resist the pulse of
+light, and consequently, that most of the Rays incident on it enter into
+it, and are refracted towards the _perpendicular_; whereas the air I
+suppose to be a body that does more resist it, and consequently more are
+_re-percuss'd_ then do enter it: the same kind of trials have I made, with
+_Crystalline Glass_, with drops of fluid bodies, and several other ways,
+which do all seem to agree very exactly with this _Theory_. So that from
+this Principle well establish'd, we may deduce severall Corollaries not
+unworthy observation.
+
+And the first is; that it plainly appears by this, that the production of
+the Rainbow is as much to be ascribed to the reflection of the concave
+surface of the air, as to the refraction of the _Globular_ drops: this will
+be evidently manifest by these Experiments, if you _foliate_ that part of a
+Glass-ball that is to reflect an _Iris_, as in the _Cartesian_ Experiment,
+above mention'd, the reflections will be abundantly more strong, and the
+colours more vivid: and if that part of the surface be touch'd with Water,
+scarce affords any sensible colour at all.
+
+Next we learn, that the great reason why _pellucid_ bodies beaten small are
+white, is from the multitude of reflections, not from the particles of the
+body, but from the _contiguous_ surface of the air. And this is evidently
+manifested, by filling the _Interstitia_ of those powder'd bodies with
+Water, whereby their whiteness presently disappears. From the same reason
+proceeds the whiteness of many kinds of Sands, which in the _Microscope_
+appear to be made up of a multitude of little _pellucid_ bodies, whose
+brightest reflections may by the _Microscope_ be plainly perceiv'd to come
+from their internal surfaces; and much of the whiteness of it may be
+destroy'd by the affusion of fair Water to be contiguous to those surfaces.
+
+The whiteness also of froth, is for the most part to be ascribed to the
+reflection of the light from the surface of the air within the Bubbles, and
+very little to the reflection from the surface of the Water it self: for
+this last reflection does not return a quarter so many Rays, as that which
+is made from the surface of the air, as I have certainly found by a
+multitude of Observations and Experiments.
+
+The whiteness of _Linnen_, _Paper_, _Silk_, &c. proceeds much from the same
+reason, as the _Microscope_ will easily discover; for the Paper is made up
+of an abundance of _pellucid_ bodies, which afford a very plentifull
+reflection from within, that is, from the concave surface of the air
+contiguous to its component particles; wherefore by the affusion of Water,
+Oyl, Tallow, Turpentine, &c. all those reflections are made more faint, and
+the beams of light are suffer'd to traject & run through the Paper more
+freely.
+
+Hence further we may learn the reason of the whiteness of many bodies, and
+by what means they maybe in part made _pellucid_: As white Marble for
+instance, for this body is composed of a _pellucid_ body exceedingly
+flaw'd, that is, there are abundance of thin, and very fine cracks or
+chinks amongst the multitude of particles of the body, that contain in them
+small parcels of air, which do so _re-percuss_ and drive back the
+penetrating beams, that they cannot enter very deep within that body; which
+the _Microscope_ does plainly inform us to be made up of a _Congeries_ of
+_pellucid_ particles. And I further found it somewhat more evidently by
+some attempts I made towards the making transparent Marble, for by heating
+the Stone a little, and baking it in Oyl, Turpentine, Oyl of Turpentine,
+&c., I found that I was able to see much deeper into the body of Marble
+then before; and one trial, which was not with an unctuous substance,
+succeeded better than the rest, of which, when I have a better opportunity,
+I shall make further trial.
+
+This also gives us a probable reason of the so much admired _Phænomena_, of
+the _Oculus Mundi_, an _Oval_ stone, which commonly looks like white
+Alabaster, but being laid a certain time in Water, it grows _pellucid_, and
+transparent, and being suffer'd to lie again dry, it by degrees loses that
+transparency, and becomes white as before. For the Stone being of a hollow
+spongie nature, has in the first and last of these appearances, all those
+pores fill'd with the obtunding and reflecting air; whereas in the second,
+all those pores are fill'd with a _medium_ that has much the same
+refraction with the particles of the Stone, and therefore those two being
+_contiguous_, make, as 'twere, one _continued medium_, of which more is
+said in the 15. _Observation_.
+
+There are a multitude of other _Phænomena_, that are produc'd from this
+same Principle, which as it has not been taken notice of by any yet that I
+know, so I think, upon more diligent observation, will it not be found the
+least considerable. But I have here onely time to hint _Hypotheses_, and
+not to prosecute them so fully as I could wish; many of them having a vast
+extent in the production of a multitude of _Phænomena_, which have been by
+others, either not attempted to be explain'd, or else attributed to some
+other cause than what I have assign'd, and perhaps than the right; and
+therefore I shall leave this to the prosecution of such as have more
+leisure: onely before I leave it, I must not pretermit to hint, that by
+this Principle, multitudes of the _Phænomena_ of the air, as about _Mists_,
+_Clouds_, _Meteors_, _Haloes_, &c. are most plainly and (perhaps) truly
+explicable; multitudes also of the _Phænomena_ in colour'd bodies, as
+liquors, &c. are deducible from it.
+
+And from this I shall proceed to a second considerable _Phænomenon_ which
+these Diamants exhibit, and that is the regularity of their _Figure_, which
+is a propriety not less general than the former, It comprising within its
+extent, all kinds of _Metals_, all kinds of _Minerals_, most _Precious
+stones_, all kinds of _Salts_, multitudes of _Earths_, and almost all kinds
+of _fluid bodies_. And this is another propiety, which, though a little
+superficially taken notice of by some, has not, that I know, been so much
+as attempted to be explicated by any.
+
+This propriety of bodies, as I think it the most worthy, and next in order
+to be consider'd after the contemplation of the _Globular Figure_, so have
+I long had a desire as wel as a determination to have prosecuted it if I
+had had an opportunity, having long since propos'd to my self the method of
+my enquiry therein, it containing all the allurements that I think any
+enquiry is capable of: For, first I take it to proceed from the most simple
+principle that any kind of form can come from, next the _Globular_, which
+was therefore the first I set upon, and what I have therein perform'd, I
+leave the Judicious Reader to determine. For as that form proceeded from a
+propiety of fluid bodies, which I have call'd _Congruity_, or
+_Incongruity_; so I think, had I time and opportunity, I could make
+probable, that all these regular Figures that are so conspicuously
+_various_ and _curious_, and do so adorn and beautifie such multitudes of
+bodies, as I have above hinted, arise onely from three or four several
+positions or postures of _Globular_ particles, and those the most plain,
+obvious, and necessary conjunctions of such figur'd particles that are
+possible, so that supposing such and such plain and obvious causes
+concurring the _coagulating particles_ must necessarily compose a body of
+such a determinate regular Figure, and no other, and this with as much
+necessity and obviousness as a fluid body encompast with a _Heterogeneous_
+fluid must be protruded into a _Spherule_ or _Globe_. And this I have _ad
+oculum_ demonstrated with a company of bullets, and some few other very
+simple bodies; so that there was not any regular Figure, which I have
+hitherto met withall, of any of those bodies that I have above named, that
+I could not with the composition of bullets or globules, and one or two
+other bodies, imitate, even almost by shaking them together. And thus for
+instance may we find that the _Globular_ bullets will of themselves, if put
+on an inclining plain, so that they may run together, naturally run into a
+_triangular_ order, composing all the variety of figures that can be
+imagin'd to be made out of _æquilateral triangles_; and such will you find,
+upon trial, all the Surfaces of _Alum_ to be compos'd of: For three bullets
+lying on a plain, as close to one another as they can compose an
+_æquilatero-triangular_ form, as in A in the 7. _Scheme_. If a fourth be
+joyn'd to them on either side as closely as it can, they four compose the
+most regular Rhombus consisting of two _æquilateral triangles_, as B. If a
+fifth be joyn'd to them on either side in as close a position as it can,
+which is the propriety of the _Texture_, it makes a _Trapezium_, or
+four-sided Figure, two of whole angles are 120. and two 60. degrees, as C.
+If a sixth be added, as before, either it makes an _æquilateral triangle_,
+as D, or a Rhomboeid, as E, or an _Hex-angular Figure_, as F, which is
+compos'd of two _primary Rhombes_. If a seventh be added, it makes either
+an _æquilatero-hexagonal_ Figure, as G, or some kind of six-sided _Figure_,
+as H, or I. And though there be never so many placed together, they may be
+rang'd into some of these lately mentioned Figures, all the angles of which
+will be either _60_. degrees, or 120. as the figure K. which is an
+_æquiangular hexagonal_ Figure is compounded of 12. _Globules_, or may be
+of 25, or 27, or 36, or 42, &c. and by these kinds of texture, or position
+of globular bodies, may you find out all the variety of regular shapes,
+into which the smooth surfaces of _Alum_ are form'd, as upon examination
+any one may easily find; nor does it hold only in superficies, but in
+solidity also, for it's obvious that a fourth _Globule_ laid upon the third
+in this texture, composes a regular _Tetrahedron_, which is a very usual
+Figure of the _Crystals_ of _Alum_. And (to hasten) there is no one Figure
+into which _Alum_ is observ'd to be crystallized, but may by this texture
+of _Globules_ be imitated, and by no other.
+
+I could instance also in the Figure of _Sea-salt_, and _Sal-gem_, that it
+is compos'd of a texture of _Globules_, placed in a _cubical_ form, as L,
+and that all the Figures of those Salts may be imitated by this texture of
+_Globules_ and by no other whatsoever. And that the forms of _Vitriol_ and
+of _Salt-Peter_, as also of _Crystal_, _Hore-frost_, &c. are compounded of
+these two textures, but modulated by certain proprieties: But I have not
+here time to insist upon, as I have not neither to shew by what means
+_Globules_ come to be thus context, and what those _Globules_ are, and many
+other particulars requisite to a full and intelligible explication of this
+propriety of bodies. Nor have I hitherto found indeed an opportunity of
+prosecuting the inquiry so farr as I design'd; nor do I know when I may, it
+requiring abundance of time, and a great deal of assistance to go through
+with what I design'd; the model of which was this:
+
+First, to get as exact and full a collection as I could, of all the
+differing kinds of Geometrical figur'd bodies, some three or four several
+bodies of each kind.
+
+Secondly, with them to get as exact a History as possibly I could learn of
+their places of Generation or finding, and to enquire after as many
+circumstances that tended to the Illustrating of this Enquiry, as possibly
+I could observe.
+
+Thirdly, to make as many trials as upon experience I could find requisite,
+in Dissolutions and Coagulations of several crystallizing Salts; for the
+needfull instruction and information in this Enquiry.
+
+Fourthly, to make several trials on divers other bodies, as Metals,
+Minerals, and Stones, by dissolving them in several _Menstruums_, and
+crystalizing them, to see what Figures would arise from those several
+_Compositums_.
+
+Fifthly, to make Compositions and Coagulations of several Salts together
+into the same mass, to observe of what Figure the product of them would be;
+and in all, to note as many circumstances as I should judge conducive to my
+Enquiry.
+
+Sixthly, to enquire the closeness or rarity of the texture of these bodies,
+by examining their gravity, and their refraction, &c.
+
+Seventhly, to enquire particularly what operations the fire has upon
+several kinds of Salts, what changes it causes in their Figures, Textures,
+or Energies.
+
+Eighthly, to examine their manner of dissolution, or acting upon those
+bodies dissoluble in them; The texture of those bodies before and after the
+process. And this for the History.
+
+Next for the Solution, To have examin'd by what, and how many means, such
+and such Figures, actions and effects could be produc'd possibly.
+
+And lastly, from all circumstances well weigh'd, I should have endeavoured
+to have shewn which of them was most likely, and (if the informations by
+these Enquiries would have born it) to have demonstrated which of them it
+must be, and was.
+
+But to proceed, As I believe it next to the Globular the most simple; so do
+I, in the second place, judge it not less pleasant; for that which makes an
+Enquiry pleasant, are, first a noble _Inventum_ that promises to crown the
+successfull endeavour; and such must certainly the knowledge of the
+efficient and concurrent causes of all these curious Geometrical Figures
+be, which has made the Philosophers hitherto to conclude nature in these
+things to play the Geometrician, according to that saying of _Plato_,
+[Greek: Ho Theos geometrei]. Or next, a great variety of matter in the
+Enquiry; and here we meet with nothing less than the _Mathematicks_ of
+nature, having every day a new Figure to contemplate, or a variation of the
+same in another body,
+
+Which do afford us a third thing, which will yet more sweeten the Enquiry,
+and that is, a multitude of information; we are not so much to grope in the
+dark, as in most other Enquiries, where the _Inventum_ is great; for having
+such a multitude of instances to compare, and such easie ways of
+generating, or compounding and of destroying the form, as in the _Solution_
+and _Crystallization_ of Salts, we cannot but learn plentifull information
+to proceed by. And this will further appear from the universality of the
+Principle which Nature has made use of almost in all inanimate bodies. And
+therefore, as the contemplation of them all conduces to the knowledg of any
+one; so from a Scientifical knowledge of any one does follow the fame of
+all, and every one.
+
+And fourthly, for the usefulness of this knowledge, when acquir'd;
+certainly none can doubt, that considers that it caries us a step forward
+into the Labirinth of Nature, in the right way towards the end we propose
+our selves in all Philosophical Enquiries. So that knowing what is the form
+of Inanimate or Mineral bodies, we shall be the better able to proceed in
+our next Enquiry after the forms of Vegetative bodies; and last of all, of
+Animate ones, that seeming to be the highest step of natural knowledge that
+the mind of man is capable of.
+
+       *       *       *       *       *
+
+
+Observ. XIV. _Of several kindes of frozen _Figures_._
+
+I have very often in a Morning, when there has been a great _hoar-frost_,
+with an indifferently magnifying _Microscope_, observ'd the small _Stiriæ_,
+or Crystalline beard, which then usually covers the face of most bodies
+that lie open to the cold air, and found them to be generally _Hexangular
+prismatical_ bodies, much like the long Crystals of _Salt-peter_, save
+onely that the ends of them were differing: for whereas those of _Nitre_
+are for the most part _pyramidal_, being terminated either in a point or
+edge; these of Frost were hollow, and the cavity in some seem'd pretty
+deep, and this cavity was the more plainly to be seen, because usually one
+or other of the six _parallelogram_ sides was wanting, or at least much
+shorter then the rest.
+
+But this was onely the Figure of the _Bearded hoar-frost_; and as for the
+particles of other kinds of _hoar-frosts_, they seem'd for the most part
+irregular, or of no certain Figure. Nay, the parts of those curious
+branchings, or _vortices_, that usually in cold weather tarnish the surface
+of Glass, appear through the _Microscope_ very rude and unshapen, as do
+most other kinds of frozen _Figures_, which to the naked eye seem exceeding
+neat and curious, such as the Figures of _Snow_, frozen _Urine_, _Hail_,
+several _Figures_ frozen in common Water, &c. Some Observations of each of
+which I shall hereunto annex, because if well consider'd and examin'd, they
+may, perhaps, prove very instructive for the finding out of what I have
+endeavoured in the preceding Observation to shew, to be (next the _Globular
+Figure_ which is caus'd by _congruity_, as I hope I have made probable in
+the sixth _Observation_) the most simple and plain operation of Nature, of
+which, notwithstanding we are yet ignorant.
+
+I.
+
+_Several Observables in the _six-branched_ Figures form'd on the surface of
+Urine by freezing._
+
+1 [11]The Figures were all frozen almost even with the surface of the
+_Urine_ in the Vessel; but the bigger stems were a little _prominent_ above
+that surface, and the parts of those stems which were nearest the center
+(a) were biggest above the surface.
+
+2 I have observ'd several kinds of these Figures, some smaller, no bigger
+then a Two-pence, others so bigg, that I have by measure found one of its
+stems or branches above four foot long; and of these, some were pretty
+round, having all their branches pretty neer alike; other of them were more
+extended towards one side, as usually those very large ones were, which I
+have observ'd in Ditches which have been full of foul water.
+
+3 None of all these Figures I have yet taken notice of, had any regular
+position in respect of one another, or of the sides of the Vessel; nor did
+I find any of them equally to exactness extended every way from the center
+a.
+
+4 Where ever there was a center, the branchings from it, ab, ac, ad, ae,
+af, ag, were never fewer, or more then six, which usually concurr'd, or met
+one another very neer in the same point or center, a; though oftentimes not
+exactly; and were enclin'd to each other by an angle, of very near sixty
+degrees, I say, very neer, because, though having endeavoured to measure
+them the most acurately I was able, with the largest Compasses I had, I
+could not find any sensible variation from that measure, yet the whole
+six-branched Figure seeming to compose a solid angle, they must necessarily
+be somewhat less.
+
+5 The middle lines or stems of these branches, ab, ac, ad, ae, af, ag,
+seem'd somewhat whiter, and a little higher then any of the _intermediate_
+branchings of these Figures; and the center a, was the most _prominent_
+part of the whole Figure, seeming the _apex_ of a solid angle or _pyramid_,
+each of the six plains being a little enclin'd below the surface of the
+_Urin_.
+
+6 The lateral branchings issuing out of the great ones, such as op, mq, &c.
+were each of them inclin'd to the great ones, by the same angle of about
+sixty degrees, as the great ones were one to another, and always the bigger
+branchings were _prominent_ above the less, and the less above the least,
+by proportionate _gradations_.
+
+7 The _lateral_ branches shooting out of the great ones, went all of them
+from the center, and each of them was parallel to that great branch, next
+to which it lay; so that as all the branches on one side were parallel to
+one another, so were they all of them to the _approximate_ great branch, as
+po, qr, as they were parallel to each other, and shot from the center, so
+were they parallel also to the great branch ab.
+
+8 Some of the stems of the six branches proceeded straight, and of a
+thickness that gradually grew sharper towards the end, as ag.
+
+9 Others of the stems of those branches grew bigger and knotty towards the
+middle, and the branches also as well as stems, from Cylinders grew into
+Plates, in a most admirable and curious order, so exceeding regular and
+delicate, as nothing could be more, as is visible in ab, ac, ad, ae, af,
+but towards the end of some of these stems, they began again to grow
+smaller and to recover their former branchings, as about k and n.
+
+10 Many of the _lateral_ branches had _collateral_ branches (if I may so
+call them) as qm had many such as st, and most of those again
+_subcollateral_, as vw, and these again had others less, which one may call
+_laterosubcollateral_, and these again others, and they others, &c. in
+greater Figures.
+
+11 The branchings of the main Stems joyn'd not together by any regular
+line, nor did one side of the one lie over the other side of the other, but
+the small _collateral_ and _subcollateral_ branches did lie at top of one
+another according to a certain order or method, which I always observ'd to
+be this.
+
+12 That side of a _collateral_ or _subcollateral_, &c. branch, lay over the
+side of the _approximate_ (as the feathers in the wing of a Bird) whose
+branchings proceeded parallel to the last biggest stem from which it
+sprung, and not to the biggest stem of all, unless that were a second stem
+backwards.
+
+13 This rule that held in the branchings of the _Sexangular Figure_ held
+also in the branchings of any other great or small stem, though it did not
+proceed from a center.
+
+14 The exactness and curiosity of the figuration of these branches, was in
+every particular so transcendent, that I judge it almost impossible for
+humane art to imitate.
+
+15 Tasting several cleer pieces of this _Ice_, I could not find any
+_Urinous_ taste in them, but those few I tasted, seem'd as _insipid_ as
+water.
+
+16 A figuration somewhat like this, though indeed in some particulars much
+more curious, I have several times observ'd in _regulus martis stellatus_,
+but with this difference, that all the stems and branchings are bended in a
+most excellent and regular order, whereas in _Ice_ the stems and branchings
+are streight, but in all other particulars it agrees with this, and seems
+indeed nothing but one of these stars, or branched Figures frozen on
+_Urine_, distorted, or wreathed a little, with a certain proportion: _Lead_
+also that has _Arsenick_ and some other things mixt with it, I have found
+to have its surface, when suffer'd to cool, figured somewhat like the
+branchings of _Urine_, but much smaller.
+
+17 But there is a _Vegetable_ which does exceedingly imitate these
+branches, and that is, _Fearn_, where the main stem may be observ'd to
+shoot out branches, and the stems of each of these _lateral_ branches, to
+send forth _collateral_, and those _subcollateral_ and those
+_laterosubcollateral,_ &c. and all those much after the same order with the
+branchings, divisions, and subdivisions in the branchings of these Figures
+in frozen _Urine_; so that if the Figures of both be well consider'd, one
+would ghess that there were not much greater need of a _seminal principle_
+for the production of _Fearn_, then for the production of the branches of
+_Urine_, or the _Stella martis_, there seeming to be as much form and
+beauty in the one as in the other.
+
+And indeed, this Plant of _Fearn_, if all particulars be well consider'd,
+will seem of as simple, and uncompounded a form as any _Vegetable_, next to
+_Mould_ or _Mushromes_, and would next after the invention of the forms of
+those, deserve to be enquir'd into; for notwithstanding several have
+affirm'd it to have seed, and to be propagated thereby; yet, though I have
+made very diligent enquiry after that particular, I cannot find that there
+is any part of it that can be imagin'd to be more seminal then another: But
+this onely here by the by:
+
+For the freezing Figures in _Urine_, I found it requisite,
+
+First, that the Superficies be not disturbed with any wind, or other
+commotion of the air, or the like.
+
+Secondly, that it be not too long exposed, so as that the whole bulk be
+frozen, for oftentimes, in such cases, by reason of the swelling the of
+_Ice_, or from some other cause, the curious branched Figures disappear.
+
+Thirdly, an artificial freezing with _Snow_ and _Salt_, apply'd to the
+outside of the containing Vessel, succeeds not well, unless there be a very
+little quantity in the Vessel.
+
+Fourthly, If you take any cleer and smooth Glass, and wetting all the
+inside of it with _Urine_, you expose it to a very sharp freezing, you will
+find it cover'd with a very regular and curious Figure.
+
+II.
+
+_Observables in figur'd _Snow_._
+
+Exposing a piece of black Cloth, or a black Hatt to the falling _Snow_, I
+have often with great pleasure, observ'd such an infinite variety of
+curiously figur'd _Snow_, that it would be as impossible to draw the Figure
+and shape of every one of them, as to imitate exactly the curious and
+Geometrical _Mechanisme_ of Nature in any one. Some coorse draughts, such
+as the coldness of the weather, and the ill provisions, I had by me for
+such a purpose, would permit me to make, I have here added in the Second
+_Figure_ of the Eighth _Scheme_.[12]
+
+In all which I observ'd, that if they were of any regular Figures, they
+were always branched out with six principal branches, all of equal length,
+shape and make, from the center, being each of them inclin'd to either of
+the next branches on either side of it, by an angle of sixty degrees.
+
+Now, as all these stems were for the most part in one flake exactly of the
+same make, so were they in differing Figures of very differing ones; so
+that in a very little time I have observ'd above an hundred several cizes
+and shapes of these starry flakes.
+
+The branches also out of each stem of any one of these flakes, were exactly
+alike in the same flake; so that of whatever Figure one of the branches
+were, the other five were sure to be of the same, very exactly, that is, if
+the branchings of the one were small _Perallelipipeds_ or Plates, the
+branchings of the other five were of the same; and generally, the
+branchings were very conformable to the rules and method observ'd before,
+in the Figures on _Urine_, that is, the branchings from each side of the
+stems were parallel to the next stem on that side, and if the stems were
+plated, the branches also were the same; if the stems were very long, the
+branches also were so, &c.
+
+Observing some of these figur'd flakes with a _Microscope_, I found them
+not to appear so curious and exactly figur'd as one would have imagin'd,
+but like Artificial Figures, the bigger they were magnify'd, the more
+irregularites appear'd in them; but this irregularity seem'd ascribable to
+the thawing and breaking of the flake by the fall, and not at all to the
+defect of the _plastick_ virtue of Nature, whose curiosity in the formation
+of most of these kind of regular Figures, such as those of _Salt_,
+_Minerals_, &c. appears by the help of the _Microscope_, to be very many
+degrees smaller then the most acute eye is able to perceive without it. And
+though one of these six-branched Stars appear'd here below much of the
+shape described in the Third _Figure_ of the Eighth _Scheme_; yet I am very
+apt to think, that could we have a sight of one of them through a
+_Microscope_ as they are generated in the Clouds before their Figures are
+vitiated by external accidents, they would exhibit abundance of curiosity
+and neatness there also, though never so much magnify'd: For since I have
+observ'd the Figures of _Salts_ and _Minerals_ to be some of them so
+exceeding small, that I have scarcely been able to perceive them with the
+_Microscope_, and yet have they been regular, and since (as far as I have
+yet examin'd it) there seems to be but one and the same cause that produces
+both these effects, I think it not irrational to suppose that these pretty
+figur'd Stars of _Snow_, when at first generated might be also very regular
+and exact.
+
+III.
+
+_Several kinds of Figures in _Water_ frozen._
+
+Putting fair Water into a large capacious Vessel of _Glass_, and exposing
+it to the cold, I observ'd after a little time, several broad, flat, and
+thin _laminæ_, or plates of _Ice_, crossing the bulk of the water and one
+another very irregularly, onely most of them seem'd to turn one of their
+edges towards that side of the Glass which was next it, and seem'd to grow,
+as 'twere from the inside of the Vessel inwards towards the middle, almost
+like so many blades of _Fern_. Having taken several of these plates out of
+water on the blade of a Knife, I observ'd them figur'd much after the
+manner of _Herring bones_, or _Fern blades_, that is, there was one bigger
+stem in the middle like the back-bone, and out of it, on either side, were
+a multitude of small _stiriæ_, or _icicles_, like the smaller bones, or the
+smaller branches in _Fern_, each of these branches on the one side, were
+parallel to all the rest on the same side, and all of them seem'd to make
+an angle with the stem, towards the top, of sixty degrees, and towards the
+bottom or root of this stem, of 120. See the fourth _Figure_ of the 8.
+_Plate_.
+
+I observ'd likewise several very pretty Varieties of Figures in Water,
+frozen on the top of a broad flat Marble-stone, expos'd to the cold with a
+little Water on it, some like feathers, some of other shapes, many of them
+were very much of the shape exprest in the fifth Figure of the 8. _Scheme_,
+which is extremely differing from any of the other Figures.
+
+I observ'd likewise, that the shootings of _Ice_ on the top of Water,
+beginning to freez, were in streight _prismatical_ bodies much like those
+of _roch-peter_, that they crost each other usually without any kind of
+order or rule, that they were always a little higher then the surface of
+the Water that lay between them; that by degrees those _interjacent_ spaces
+would be fill'd with _Ice_ also, which usually would be as high as the
+surface of the rest.
+
+In flakes of _Ice_ that had been frozen on the top of Water to any
+considerable thickness, I observ'd that both the upper and the under sides
+of it were curiously quill'd, furrow'd, or grain'd, as it were, which when
+the Sun shone on the Plate, was exceeding easily to be perceiv'd to be much
+after the shape of the lines in the 6. _Figure_ of the 8. _Scheme_, that
+is, they consisted of several streight ends of parallel Plates, which were
+of divers lengths and angles to one another without any certain order.
+
+The cause of all which regular Figures (and of hundreds of others, namely
+of _Salts_, _Minerals_, _Metals,_ &c. which I could have here inserted,
+would it not have been too long) seems to be deducible from the same
+Principles, which I have (in the 13. _Observation_) hinted only, having not
+yet had time to compleat a _Theory_ of them. But indeed (which I there also
+hinted) I judge it the second step by which the _Pyramid_ of natural
+knowledge (which is the knowledge of the form of bodies) is to be ascended:
+And whosoever will climb it, must be well furnish'd with that which the
+Noble _Verulam_ calls _Scalam Intellectus_; he must have scaling Ladders,
+otherwise the steps are so large and high, there will be no getting up
+them, and consequently little hopes of attaining any higher station, such
+as to the knowledge of the most simple principle of Vegetation manifested
+in Mould and Mushromes, which, as I elsewhere endeavoured to shew, seems to
+be the third step; for it seems to me, that the Intellect of man is like
+his body, destitute of wings, and cannot move from a lower to a higher and
+more sublime station of knowledg, otherwise then step by step, nay even
+there where the way is prepar'd and already made passible; as in the
+_Elements of Geometry_, or the like, where it is fain to climb a whole
+_series_ of Propositions by degrees, before it attains the knowledge of one
+_Probleme_. But if the ascent be high, difficult and above its reach, it
+must have recourse to a _novum organum_, some new engine and contrivance,
+some new kind of _Algebra_, or _Analytick Art_ before it can surmount it.
+
+       *       *       *       *       *
+
+
+Observ. XV. _Of _Kettering-stone_, and of the pores of _Inanimate_ bodies._
+
+[13]This Stone which is brought from _Kettering_ in _Northampton-Shire_,
+and digg'd out of a Quarry, as I am inform'd, has a grain altogether
+admirable, nor have I ever seen or heard of any other stone that has the
+like. It is made up of an innumerable company of small bodies, not all of
+the same cize or shape, but for the most part, not much differing from a
+Globular form, nor exceed they one another in Diameter above three or four
+times; they appear to the eye, like the Cobb or Ovary of a _Herring_, or
+some smaller fishes, but for the most part, the particles seem somewhat
+less, and not so uniform; but their variation from a perfect globular ball,
+seems to be only by the pressure of the _contiguous_ bals which have a
+little deprest and protruded those toucht sides inward, and forc'd the
+other sides as much outwards beyond the limits of a Globe; just as it would
+happen, if a heap of exactly round Balls of soft Clay were heaped upon one
+another; or, as I have often seen a heap of small Globules of
+_Quicksilver_, reduc'd to that form by rubbing it much in a glaz'd Vessel,
+with some slimy or sluggish liquor, such as Spittle, when though the top of
+the upper Globules be very neer spherical, yet those that are prest upon by
+others, exactly imitate the forms of these lately mention'd grains.
+
+Where these grains touch each other, they are so firmly united or settled
+together, that they seldom part without breaking a hole in one or th'other
+of them, such as a, a, a, b, c, c, &c. Some of which fractions, as a, a, a,
+a, where the touch has been but light, break no more then the outward
+crust, or first shell of the stone, which is of a white colour, a little
+dash'd with a brownish Yellow, and is very thin, like the shell of an Egg:
+and I have seen some of those grains perfectly resemble some kind of Eggs,
+both in colour and shape: But where the union of the _contiguous granules_
+has been more firm, there the divulsion has made a greater Chasm, as at b,
+b, b, in so much that I have observ'd some of them quite broken in two, as
+at c, c, c, which has discovered to me a further resemblance they have to
+Eggs, they having an appearance of a white and yelk, by two differing
+substances that envelope and encompass each other.
+
+That which we may call the white was pretty whitish neer the yelk, but more
+duskie towards the shell; some of them I could plainly perceive to be shot
+or radiated like a _Pyrites_ or _fire-stone_; the yelk in some I saw
+hollow, in others fill'd with a duskie brown and porous substance like a
+kind of pith.
+
+The small pores, or _interstitia_ eeee betwixt the Globules, I plainly saw,
+and found by other trials to be every way pervious to air and water, for I
+could blow through a piece of this stone of a considerable thickness, as
+easily as I have blown through a Cane, which minded me of the pores which
+_Des Cartes_ allow his _materia subtilis_ between the _æthereal_ globules.
+
+The object, through the _Microscope_, appears like a _Congeries_ or heap of
+Pibbles, such as I have often seen cast up on the shore, by the working of
+the Sea after a great storm, or like (in shape, though not colour) a
+company of small Globules of Quicksilver, look'd on with a _Microscope_,
+when reduc'd into that form by the way lately mentioned. And perhaps, this
+last may give some hint at the manner of the formation of the former: For
+supposing some _Lapidescent_ substance to be generated, or some way brought
+(either by some commixture of bodies in the Sea it self, or protruded in,
+perhaps, out of some _subterraneous_ caverns) to the bottom of the Sea, and
+there remaining in the form of a liquor like Quicksilver, _heterogeneous_
+to the ambient _Saline_ fluid, it may by the working and tumblings of the
+Sea to and fro be jumbled and comminuted into such Globules as may
+afterwards be hardned into Flints, the lying of which one upon another,
+when in the Sea, being not very hard, by reason of the weight of the
+incompassing fluid, may cause the undermost to be a little, though not
+much, varied from a globular Figure. But this only by the by.
+
+After what manner this _Kettering-stone_ should be generated I cannot
+learn, having never been there to view the place, and observe the
+circumstances; but it seems to me from the structure of it to be generated
+from some substance once more fluid, and afterwards by degrees growing
+harder, almost after the same manner as I supposed the generation of Flints
+to be made.
+
+But whatever were the cause of its curious texture, we may learn this
+information from it; that even in those things which we account vile, rude,
+and coorse, Nature has not been wanting to shew abundance of curiosity and
+excellent Mechanisme.
+
+We may here find a Stone by help of a _Microscope_, to be made up of
+abundance of small Balls, which do but just touch each other, and yet there
+being so many contacts, they make a firm hard mass, or a Stone much harder
+then Free-stone.
+
+Next, though we can by a _Microscope_ discern so curious a shape in the
+particles, yet to the naked eye there scarce appears any such thing; which
+may afford us a good argument to think, that even in those bodies also,
+whose _texture_ we are not able to discern, though help'd with
+_Microscopes_, there may be yet _latent_ so curious a _Schematisme_, that
+it may abundantly satisfie the curious searcher, who shall be so happy as
+to find some way to discover it.
+
+Next, we here find a Stone, though to the naked eye a very close one, yet
+every way perforated with innumerable pores, which are nothing else but the
+_interstitia_, between those multitudes of minute globular particles, that
+compose the bulk it self, and these pores are not only discover'd by the
+_Microscope_, but by this contrivance.
+
+I took a pretty large piece of this stone, and covering it all over with
+cement, save only at two opposite parts, I found my self able, by blowing
+in at one end that was left open, to blow my spittle, with which I had wet
+the other end, into abundance of bubbles, which argued these pores to be
+open and pervious through the whole stone, which affords us a very pretty
+instance of the porousness of some seemingly close bodies, of which kind I
+shall anon have occasion to subjoyn many more, tending to prove the same
+thing.
+
+I must not here omit to take notice, that in this body there is not a
+_vegetative_ faculty that should so contrive this structure for any
+peculiar use of _vegetation_ or growth, whereas in the other instances of
+vegetable porous bodies, there is an _anima_ or _forma informans_, that
+does contrive all the Structures and _Mechanismes_ of the constituting
+body, to make them subservient and usefull to the great Work or Function
+they are to perform. And so I ghess the pores in Wood, and other
+vegetables, in bones, and other Animal substances, to be as so many
+channels, provided by the Great and Alwise Creator, for the conveyance of
+appropriated juyces to particular parts. And therefore, that this may tend,
+or be pervious all towards one part, and may have impediments, as valves or
+the like, to any other; but in this body we have very little reason so
+suspect there should be any such design, for it is equally pervious every
+way, not onely forward, but backwards, and side-ways, and seems indeed much
+rather to be _Homogeneous_ or similar to those pores, which we may with
+great probability believe to be the channels of _pellucid_ bodies, not
+directed, or more open any one way, then any other, being equally pervious
+every way. And, according as these pores are more or greater in respect of
+the _interstitial_ bodies, the more transparent are the so constituted
+concretes; and the smaller those pores are, the weaker is the _Impulse_ of
+light communicated through them, though the more quick be the progress.
+
+Upon this Occasion, I hope it will not be altogether unseasonable, if I
+propound my conjectures and _Hypothesis_ about the _medium_ and conveyance
+of light.
+
+I suppose then, that the greatest part of the _Interstitia_ of the world,
+that lies between the bodies of the Sun and Starrs, and the Planets, and
+the Earth, to be an exceeding fluid body, very apt and ready to be mov'd,
+and to communicate the motion of any one part to any other part, though
+never so far distant: Nor do I much concern my self, to determine what the
+Figure of the particles of this exceedingly subtile fluid _medium_ must be,
+nor whether it have any interstitiated pores or vacuities, it being
+sufficient to solve all the _Phænomena_ to suppose it an exceedingly fluid,
+or the most fluid body in the world, and as yet impossible to determine the
+other difficulties.
+
+That being so exceeding fluid a body, it easily gives passage to all other
+bodies to move to and fro in it.
+
+That it neither receives from any of its parts, or from other bodies; nor
+communicates to any of its parts, or to any other body, any impulse, or
+motion in a direct line, that is not of a determinate quickness. And that
+when the motion is of such determinate swiftness, it both receives, and
+communicates, or propagates an impulse or motion to any imaginable distance
+in streight lines, with an unimaginable celerity and vigour.
+
+That all kind of solid bodies consist of pretty massie particles in respect
+of the particles of this fluid _medium_, which in many places do so touch
+each other, that none of this fluid _medium_ interposes much after the same
+mannner (to use a gross similitude) as a heap of great stones compose one
+great _congeries_ or mass in the midst of the water.
+
+That all fluid bodies which we may call _tangible_, are nothing but some
+more subtile parts of those particles, that serve to constitute all
+_tangible_ bodies.
+
+That the water, and such other fluid bodies, are nothing but a _congeries_
+of particles agitated or made fluid by it in the same manner as the
+particles of _Salt_ are agitated or made fluid by a parcel of water, in
+which they are dissolv'd, and subsiding to the bottom of it, constitute a
+fluid body, much more massie and dense, and less fluid then the pure water
+it self.
+
+That the air on the other side is a certain company of particles of quite
+another kind, that is, such as are very much smaller, and more easiely
+moveable by the motion of this fluid _medium_; much like those very subtile
+parts of _Cochenel_, other very deep tinging bodies, where by a very small
+parcel of matter is able to tinge and diffuse it self over a very great
+quantity of the fluid dissolvent; or somewhat after that manner, as smoak,
+and such like minute bodies, or steams, are observ'd to tinge a very great
+quantity of air; onely this last similitude is deficient in one propriety,
+and that is a perpetuity or continuance in that state of commixture with
+the air, but the former does more neerly approach to the nature and manner
+of the air's being dissolv'd by this fluid or _Æther_. And this Similitude
+will further hold in these proprieties; that as those tinctures may be
+increased by certain bodies, so may they be precipitated by others, as I
+shall afterwards shew it to be very probable, that the like accidents
+happen even to the Air it self.
+
+Further, as these solutions and tinctures do alter the nature of these
+fluid bodies, as to their aptness to propagate a motion or impulse through
+them, even so does the particles of the Air, Water, and other fluid bodies,
+and of Glass, Crystal, &c. which are commixt with this bulk of the _Æther_
+alter the motion of the propagated pulse of light; that is, where these
+more bulkie particles are more plentifull, and consequently a lesser
+quantity of the _Æther_ between them to be mov'd, there the motion must
+necessarily be the swifter, though not so robust, which will produce those
+effects, which I have (I hope) with some probability, ascribed to it in the
+digression about Colours, at the end of the _Observations_ on
+_Muscovy-glass._
+
+Now, that other Stones, and those which have the closest and hardest
+textures, and seem (as far as we are able to discover with our eyes, though
+help'd with the best _Microscopes_) freest from pores, are yet
+notwithstanding replenish'd with them, an Instance or two will, I suppose,
+make more probable.
+
+A very solid and unflaw'd piece of cleer white _Marble_, if it be well
+polish'd and glaz'd, has so curiously smooth a surface, that the best and
+most polish'd surface of any wrought-glass, seems not to the naked eye, nor
+through a _Microscope_, to be more smooth, and less porous. And yet, that
+this hard close body is replenish'd with abundance of pores, I think these
+following Experiments will sufficiently prove.
+
+The first is, That if you take such a piece, and for a pretty while boyl it
+in Turpentine and Oyl of Turpentine, you shall find that the stone will be
+all imbu'd with it; and whereas before it look'd more white, but more
+opacous, now it will look more greasie, but be much more transparent, and
+if you let it lie but a little while, and then break off a part of it, you
+shall find the unctuous body to have penetrated it to such a determinate
+depth every way within the surface. This may be yet easier try'd with a
+piece of the same _Marble_, a little warm'd in the fire, and then a little
+Pitch or Tarr melted on the top of it; for these black bodies, by their
+insinuating themselves into the invisible pores of the stone, ting it with
+so black a hue, that there can be no further doubt of the truth of this
+assertion, that it abounds with small imperceptible pores.
+
+Now, that other bodies will also sink into the pores of _Marble_, besides
+unctuous, I have try'd, and found, that a very Blue tincture made in
+_spirit of Urine_ would very readily and easily sink into it, as would also
+several tinctures drawn with _spirit of Wine_.
+
+Nor is _Marble_ the only seemingly close stone, which by other kinds of
+Experiments may be found porous; for I have by this kind of Experiment on
+divers other stones found much the same effect, and in some, indeed much
+more notable. Other stones I have found so porous, that with the
+_Microscope_ I could perceive several small winding holes, much like
+Worm-holes, as I have noted in some kind of _Purbeck-stone_, by looking on
+the surface of a piece newly flaw'd off, for if otherwise, the surface has
+been long expos'd to the Air, or has been scraped with any tool, those
+small caverns are fill'd with dust, and disappear.
+
+And to confirm this _Conjecture_, yet further, I shall here insert an
+excellent account, given into the _Royal Society_ by that Eminently Learned
+Physician, Doctor _Goddard_, of an Experiment, not less instructive then
+curious and accurate, made by himself on a very hard and seemingly close
+stone call'd _Oculus Mundi_, as I find it preserv'd in the Records of that
+Honourable Society.
+
+    A small stone of the kind, call'd by some Authours, _Oculus Mundi_,
+    being dry and cloudy, weigh'd 5-209/256 _Grains_.
+
+    The same put under water for a night, and somewhat more, became
+    transparent, and the superficies being wiped dry, weighed 6-3/256
+    _Grains_.
+
+    The difference between these two weights, 0-50/256 of a _Grain_.
+
+    The same Stone kept out of water one Day and becoming cloudy again
+    weighed, 5-225/256 _Graines_.
+
+    Which was more then the first weight, 0-16/256 of a _Grain_.
+
+    The same being kept two Days longer weighed, 5-202/256 _Graines_.
+
+    Which was less then at first, 0-7/256 a _Grain_.
+
+    Being kept dry something longer it did not grow sensibly lighter.
+
+    Being put under water for a night and becoming again transparent and
+    wiped dry, the weight was, _6-3/256 Grains_, the same with the first
+    after putting in water, and more then the last weight after keeping of
+    it dry, 0-57/256 of a _Grain_.
+
+    Another Stone of the same kind being variegated with milky _white_ and
+    _gray_ like some sorts of _Agates_, while it lay under water, was
+    alwaies invironed with little Bubbles, such as appear in water a little
+    before boyling, next the sides of the Vessel.
+
+    There were also some the like Bubbles on the Surface of the water just
+    over it, as if either some exhalations came out of it, or that it did
+    excite some fermentation in the parts of the water contiguous to it.
+
+    There was little sensible difference in the transparency of this Stone,
+    before the putting under water, and after: To be sure the milky-_white_
+    parts continued as before, but more difference in weight then in the
+    former. For whereas before the putting into the water the weight was
+    18-97/128 _Graines_. After it had lyen in about four and twenty hours
+    the weight was 20-27/128 _Graines_, so the difference was, 1-58/128
+    _Graines_.
+
+    The same Stone was infused in the water scalding hot, and so continued
+    for a while after it was cold, but got no more weight then upon
+    infusing in the cold, neither was there any sensible Difference in the
+    weight both times.
+
+In which Experiment, there are three Observables that seem very manifestly
+to prove the porousness of these seemingly close bodies: the first is their
+acquiring a transparency, and losing their whiteness after steeping in
+water, which will seem the more strongly to argue it, if what I have
+already said about the making transparent, or clarifying of some bodies, as
+the white powder of beaten Glass, and the froth of some glutinous
+transparent liquor be well consider'd; for thereby it will seem rational to
+think that this transparency arises from the insinuation of the water
+(which has much the same refraction with such stony particles, as may be
+discover'd by Sand view'd with a _Microscope_) into those pores which were
+formerly repleat with air (that has a very differing refraction, and
+consequently is very reflective) which seems to be confirm'd by the second
+Observable, namely, the increase of weight after keeping, and decrease upon
+drying. And thirdly, seem'd yet more sensibly confirm'd by the multitude of
+bubbles in the last Experiment.
+
+We find also most Acid Salts very readily to dissolve and separate the
+parts of this body one from another; which is yet a further Argument to
+confirm the porousness of bodies, and will serve as such, to shew that even
+Glass also has an abundance of pores in it, since there are several
+liquors, that with long staying in a Glass, will so _Corrode_ and eat into
+it, as at last, to make it pervious to the liquor it contain'd, of which I
+have seen very many Instances.
+
+Since therefore we find by other proofs, that many of those bodies which we
+think the most solid ones, and appear so to our sight, have notwithstanding
+abundance of those grosser kind of pores, which will admit several kinds of
+liquors into them, why should we not believe that Glass, and all other
+transparent bodies abound with them, since we have many other arguments,
+besides the propagation of light, which seem to argue for it?
+
+And whereas it may be objected, that the propagation of light is no
+argument that there are those atomical pores in glass, since there are
+_Hypotheses_ plausible enough to solve those _Phænomena_, by supposing the
+pulse onely to be communicated through the transparent body.
+
+To this I answer, that that _Hypothesis_ which the industrious _Mersennus_
+has publish'd about the slower motion of the end of a Ray in a denser
+_medium_, then in a more rare and thin, seems altogether unsufficient to
+solve abundance of _Phænomena_, of which this is not the least
+considerable, that it is impossible from that supposition, that any colours
+should be generated from the refraction of the Rays; for since by that
+_Hypothesis_ the _undulating pulse_ is always carried perpendicular, or at
+right angles with the Ray or Line of direction, it follows, that the stroke
+of the pulse of light, after it has been once or twice refracted (through a
+Prisme, for example) must affect the eye with the same kind of stroke as if
+it had not been refracted at all. Nor will it be enough for a Defendant of
+that _Hypothesis_, to say, that perhaps it is because the refractions have
+made the Rays more weak, for if so, then two refractions in the two
+parallel sides of a _Quadrangular Prisme_ would produce colours, but we
+have no such _Phænomena_ produc'd.
+
+There are several Arguments that I could bring to evince that there are in
+all transparent bodies such atomical pores. And that there is such a fluid
+body as I am arguing for, which is the _medium_, or Instrument, by which
+the pulse of Light is convey'd from the _lucid body_ to the enlightn'd. But
+that it being a digression from the Observations I was recording, about the
+Pores of _Kettering Stone_, it would be too much such, if I should protract
+it too long; and therefore I shall proceed to the next _Observation_.
+
+       *       *       *       *       *
+
+
+Observ. XVI. _Of _Charcoal_, or burnt _Vegetables_._
+
+Charcoal, or a Vegetable burnt black, affords an object no less pleasant
+than instructive, for if you take a small round Charcoal, and break it
+short with your fingers, you may perceive it to break with a very smooth
+and sleek surface, almost like the surface of black sealing Wax; this
+surface, if it be look'd on with an ordinary _Microscope_, does manifest
+abundance of those pores which are also visible to the eye in many kinds of
+_Wood_, rang'd round the pith, both a in kind of circular order, and a
+radiant one. Of these there are a multitude in the substance of the Coal,
+every where almost perforating and drilling it from end to end; by means of
+which, be the Coal never so long, you may easily blow through it; and this
+you may presently find, by wetting one end of it with Spittle, and blowing
+at the other.
+
+But this is not all, for besides those many great and conspicuous irregular
+spots or pores, if a better _Microscope_ be made use of, there will appear
+an infinite company of exceedingly small, and very regular pores, so thick
+and so orderly set, and so close to one another, that they leave very
+little room or space between them to be fill'd with a solid body, for the
+apparent _interstitia_ or separating sides of these pores seem so thin in
+some places, that the texture of a Honey-comb cannot be more porous. Though
+this be not every where so, the intercurrent partitions in some places
+being very much thicker in proportion to the holes.
+
+Most of these small pores seem'd to be pretty round, and were rang'd in
+rows that radiated from the pith to the bark; they all of them seem'd to be
+continued open pores, running the whole length of the Stick; and that they
+were all perforated, I try'd by breaking off a very thin sliver of the Coal
+cross-ways, and then with my _Microscope_, diligently surveying them
+against the light, for by that means I was able to see quite through them.
+
+These pores were so exceeding small and thick, that in a line of them, 1/18
+part of an Inch long, I found by numbring them no less then 150. small
+pores; and therefore in a line of them an Inch long, must be no less then
+2700. pores, and in a circular _area_ of an Inch diameter, must be about
+5725350. of the like pores; so that a Stick of an Inch Diameter, may
+containe no less then seven hundred and twenty five thousand, besides 5
+Millions of pores, which would, I doubt not, seem even incredible, were not
+every one left to believe his own eyes. Nay, having since examin'd _Cocus,
+black and green Ebony, Lignum Vitæ_, &c. I found, that all these Woods have
+their pores, abundantly smaller then those of soft light Wood; in so much,
+that those of _Guajacum_ seem'd not above an eighth part of the bigness of
+the pores of Beech, but then the _Interstitia_ were thicker; so
+prodigiously curious are the contrivances, pipes, or sluces by which the
+_Succus nutritius_, or Juyce of a Vegetable is convey'd from place to
+place.
+
+This _Observation_ seems to afford us the true reason of several
+_Phænomena_ of Coals; as
+
+First, why they look black; and for this we need go no further then the
+_Scheme_, for certainly, a body that has so many pores in it as this is
+discover'd to have, from each of which no light is reflected, must
+necessarily look black, especially, when the pores are somewhat bigger in
+proportion to the intervals then they are cut in the _Scheme_, black being
+nothing else but a privation of Light, or a want of reflection; and
+wheresover this reflecting quality is deficient, there does that part look
+black, whether it be from a porousness of the body, as in this Instance, or
+in a deadning and dulling quality, such as I have observ'd in the _Scoria_
+of Lead, Tin, Silver, Copper, &c.
+
+Next, we may also as plainly see the reason of its shining quality, and
+that is from the even breaking off of the stick, the solid _interstitia_
+having a regular termination or surface, and having a pretty strong
+reflecting quality, the many small reflections become united to the naked
+eye, and make a very pretty shining surface.
+
+Thirdly, the reason of its hardness and brittleness seems evident, for
+since all the watery or liquid substance that moistn'd and toughn'd those
+_Interstitia_ of the more solid parts, are evaporated and remov'd, that
+which is left behind becomes of the nature almost of a stone, which will
+not at all, or very little, bend without a _divulsion_ or _solution_ of its
+_continuity_.
+
+It is not my design at present, to examine the use and _Mechanisme_ of
+these parts of Wood, that being more proper to another Enquiry; but rather
+to hint, that from this Experiment we may learn,
+
+First, what is the cause of the blackness of many burnt bodies, which we
+may find to be nothing else but this; that the heat of the fire agitating
+and rarifying the waterish, transparent, and volatile water that is
+contain'd in them, by the continuation of that action, does so totally
+expel and drive away all that which before fill'd the pores, and was
+dispers'd also through the solid mass of it, and thereby caus'd an
+universal kind of transparency, that it not onely leaves all the pores
+empty, but all the _Interstitia_ also so dry and _opacous_, and perhaps
+also yet further perforated, that that light onely is reflected back which
+falls upon the very outward edges of the pores, all they that enter into
+the pores of the body, never returning, but being lost in it.
+
+Now, that the Charring or coaling of a body is nothing else, may be easily
+believ'd by one that shall consider the means of its production, which may
+be done after this, or any such manner. The body to be charr'd or coal'd,
+may be put into a _Crucible_, Pot, or any other Vessel that will endure to
+be made red-hot in the fire without breaking, and then cover'd over with
+Sand, so as no part of it be suffer'd to be open to the Air, then set into
+a good fire, and there kept till the Sand has continu'd red hot for a
+quarter, half, an hour or two, or more, according to the nature and bigness
+of the body to be coal'd or charr'd, then taking it out of the fire, and
+letting it stand till it be quite cold, the body may be taken out of the
+Sand well charr'd and cleans'd of its waterish parts; but in the taking of
+it out, care must be had that the Sand be very neer cold, for else, when it
+comes into the free air, it will take fire, and readily burn away.
+
+This maybe done also in any close Vessel of Glass, as a _Retort_, or the
+like, and the several fluid substances that come over may be receiv'd in a
+fit _Recipient_, which will yet further countenance this _Hypothesis_: And
+their manner of charring Wood in great quantity comes much to the same
+thing, namely, an application of a great heat to the body, and preserving
+it from the free access of the devouring air; this may be easily learn'd
+from the History of Charring of Coal, most excellently describ'd and
+publish'd by that most accomplish'd Gentleman, Mr. _John Evelin_, in the
+100, 101, 103, pages of his _Sylva_, to which I shall therefore refer the
+curious Reader that desires a full information of it.
+
+Next, we may learn what part of the Wood it is that is the _combustible_
+matter, for since we shall find that none, or very little of those fluid
+substances that are driven over into the Receiver are _combustible_, and
+that most of that which is left behind is so, it follows, that the solid
+_interstitia_ of the Wood are the _combustible_ matter. Further, the reason
+why uncharr'd Wood burns with a greater flame then that which is charr'd,
+is as evident, because those waterish or volatil parts issuing out of the
+fired Wood, every way, not onely shatter and open the body, the better for
+the fire to enter, but issuing out in vapours or wind, they become like so
+many little _æolipiles_, or Bellows, whereby they blow and agitate the
+fir'd part, and conduce to the more speedy and violent consumption or
+dissolution of the body.
+
+Thirdly, from the Experiment of charring of Coals (whereby we see that
+notwithstanding the great heat, and the duration of it, the solid parts of
+the Wood remain, whilest they are preserv'd from the free access of the air
+undissipated) we may learn, that which has not, that I know of, been
+publish'd or hinted, nay, not so much as thought of, by any; and that in
+short is this.
+
+First, _that the Air_ in which we live, move, and breath, and which
+encompasses very many, and cherishes most bodies it encompasses, that this
+Air is the _menstruum_, or universal dissolvent of all _Sulphureous_
+bodies.
+
+Secondly, _that this action_ it performs not, till the body be first
+sufficiently heated, as we find requisite also to the dissolution of many
+other bodies by several other _menstruums_.
+
+Thirdly, _that this action_ of dissolution, produces or generates a very
+great heat, and that which we call Fire; and this is common also to many
+dissolutions of other bodies, made by _menstruums_, of which I could give
+multitudes of Instances.
+
+Fourthly, _that this action_ is perform'd with so great a violence, and
+does so minutely act, and rapidly agitate the smallest parts of the
+_combustible_ matter, that it produces in the _diaphanous medium_ of the
+Air, the action or pulse of light, which what it is, I have else-where
+already shewn.
+
+Fifthly, _that the dissolution_ of sulphureous bodies is made by a
+substance inherent, and mixt with the Air, that is like, if not the very
+same, with that which is fixt in _Salt-peter_, which by multitudes of
+Experiments that may be made with _Saltpeter_, will, I think, most
+evidently be demonstrated.
+
+Sixthly, _that in this dissolution_ of bodies by the Air, a certain part is
+united and mixt, or dissolv'd and turn'd into the Air, and made to fly up
+and down with it in the same manner as a _metalline_ or other body
+dissolved into any _menstruums_, does follow the motions and progresses of
+that _menstruum_ till it be precipitated.
+
+Seventhly, That as there is one part that is dissoluble by the Air, so are
+there other parts with which the parts of the Air mixing and uniting, do
+make a _Coagulum_, or _precipitation_, as one may call it, which causes it
+to be separated from the Air, but this _precipitate_ is so light, and in so
+small and rarify'd or porous clusters, that it is very volatil, and is
+easily carry'd up by the motion of the Air, though afterwards, when the
+heat and agitation that kept it rarify'd ceases, it easily condenses, and
+commixt with other indissoluble parts, it sticks and adheres to the next
+bodies it meets withall; and this is a certain _Salt_ that may be extracted
+out of _Soot_.
+
+Eighthly, that many indissoluble parts being very apt and prompt to be
+rarify'd, and so, whilest they continue in that heat and agitation, are
+lighter then the Ambient Air, are thereby thrust and carry'd upwards with
+great violence, and by that means carry along with them, not onely that
+_Saline concrete_ I mention'd before, but many terrestrial, or indissoluble
+and irrarefiable parts, nay, many parts also which are dissoluble, but are
+not suffer'd to stay long enough in a sufficient heat to make them prompt
+and apt for that action. And therefore we find in _Soot_, not onely a part,
+that being continued longer in a competent heat, will be dissolv'd by the
+Air, or take fire and burn; but a part also which is fixt, terrestrial, and
+irrarefiable.
+
+Ninthly, that as there are these several parts that will rarifie and fly,
+or be driven up by the heat, so are there many others, that as they are
+indissoluble by the _aerial menstruum_, so are they of such sluggish and
+gross parts, that they are not easily rarify'd by heat, and therefore
+cannot be rais'd by it; the volatility or fixtness of a body seeming to
+consist only in this, that the one is of a texture, or has component parts
+that will be easily rarify'd into the form of Air, and the other, that it
+has such as will not, without much ado, be brought to such a constitution;
+and this is that part which remains behind in a white body call'd Ashes,
+which contains a substance, or _Salt_, which Chymists call _Alkali_: what
+the particular natures of each of these bodies are, I shall not here
+examine, intending it in another place, but shall rather add that this
+_Hypothesis_ does so exactly agree with all _Phænomena_, of Fire, and so
+genuinely explicate each particular circumstance that I have hitherto
+observ'd, that it is more then probable, that this cause which I have
+assign'd is the true adequate, real, and onely cause of those _Phænomena_;
+And therefore I shall proceed a little further, to shew the nature and use
+of the Air.
+
+Tenthly, therefore the dissolving parts of the Air are but few, that is, it
+seems of the nature of those _Saline menstruums_, or spirits, that have
+very much flegme mixt with the spirits, and therefore a small parcel of it
+is quickly glutted, and will dissolve no more; and therefore unless some
+fresh part of this _menstruum_ be apply'd to the body to be dissolv'd, the
+action ceases, and the body leaves to be dissolv'd and to shine, which is
+the Indication of it, though plac'd or kept in the greatest heat; whereas
+_Salt-peter_ is a _menstruum_, when melted and red-hot, that abounds more
+with those Dissolvent particles, and therefore as a small quantity of it
+will dissolve a great sulphureous body, so will the dissolution be very
+quick and violent.
+
+Therefore in the _Eleventh_ place, it is observable, that, as in other
+solutions, if a copious and quick supply of fresh _menstruum_, though but
+weak, be poured on, or applied to the dissoluble body, it quickly consumes
+it: So this _menstruum_ of the Air, if by Bellows, or any other such
+contrivance, it be copiously apply'd to the shining body, is found to
+dissolve it as soon, and as violently as the more strong _menstruum_ of
+melted _Nitre_.
+
+Therefore twelfthly, it seems reasonable to think that there is no such
+thing as an Element of Fire that should attract or draw up the flame, or
+towards which the flame should endeavour to ascend out of a desire or
+appetite of uniting with that as its _Homogeneal_ primitive and generating
+Element; but that that shining transient body which we call _Flame_, is
+nothing else but a mixture of Air, and volatil sulphureous parts of
+dissoluble or combustible bodies, which are acting upon each other whilst
+they ascend, that is, flame seems to be a mixture of Air, and the
+combustible volatil parts of any body, which parts the encompassing Air
+does dissolve or work upon, which action, as it does intend the heat of the
+_aerial_ parts of the dissolvent, so does it thereby further rarifie those
+parts that are acting, or that are very neer them, whereby they growing
+much lighter then the heavie parts of that _menstruum_ that are more
+remote, are thereby protruded and driven upward; and this may be easily
+observ'd also in dissolution made by any other _menstruum_, especially such
+as either create heat or bubbles. Now, this action of the _menstruum_, or
+_Air_, on the dissoluble parts, is made with such violence, or is such,
+that it imparts such a motion or pulse to the _diaphanous_ parts of the
+Air, as I have elsewhere shewn is requisite to produce light.
+
+This _Hypothesis_ I have endeavoured to raise from an Infinite of
+Observations and Experiments, the process of which would be much too long
+to be here inserted, and will perhaps another time afford matter copious
+enough for a much larger Discourse, the Air being a Subject which (though
+all the world has hitherto liv'd and breath'd in, and been unconversant
+about) has yet been so little truly examin'd or explain'd, that a diligent
+enquirer will be able to find but very little information from what has
+been (till of late) written of it: But being once well understood, it will,
+I doubt not, inable a man to render an intelligible, nay probable, if not
+the true reason of all the _Phænomena_ of Fire, which, as it has been found
+by Writers and Philosophers of all Ages a matter of no small difficulty, as
+may be sufficiently understood by their strange _Hypotheses_, and
+unintelligible Solutions of some few _Phænomena_ of it; so will it prove a
+matter of no small concern and use in humane affairs, as I shall elsewhere
+endeavour to manifest when I come to shew the use of the Air in
+respiration, and for the preservation of the life, nay, for the
+conservation and restauration of the health and natural constitution of
+mankind as well as all other aereal _animals_, as also the uses of this
+principle or propriety of the Air in chymical, mechanical, and other
+operations. In this place I have onely time to hint an _Hypothesis_, which,
+if God permit me life and opportunity, I may elsewhere prosecute, improve
+and publish. In the mean time, before I finish this Discourse, I must not
+forget to acquaint the Reader, that having had the liberty granted me of
+making some trials on a piece of _Lignum fossile_ shewn to the Royal
+Society, by the eminently Ingenious and Learned Physician, Doctor _Ent_,
+who receiv'd it for a Present from the famous _Ingenioso Cavalliero de
+Pozzi_, it being one of the fairest and best pieces of _Lignum fossile_ he
+had seen; Having (I say) taken a small piece of this Wood, and examin'd it,
+I found it to burn in the open Air almost like other Wood, and insteed of a
+resinous smoak or fume, it yielded a very bituminous one, smelling much of
+that kind of sent: But that which I chiefly took notice of, was, that
+cutting off a small piece of it, about the bigness of my Thumb, and
+charring it in a _Crucible_ with Sand, after the manner I above prescrib'd,
+I found it infinitely to abound with the smaller sort of pores, so
+extreamly thick, and so regularly perforating the substance of it
+long-ways, that breaking it off a-cross, I found it to look very like an
+Honey-comb; but as for any of the second, or bigger kind of pores, I could
+not find that it had any; so that it seems, whatever were the cause of its
+production, it was not without those small kind of pores which we have
+onely hitherto found in Vegetable bodies: and comparing them with the pores
+which I have found in the Charcoals that I by this means made of several
+other kinds of Wood, I find it resemble none so much as those of Fire, to
+which it is not much unlike in grain also, and several other proprieties.
+
+And therefore, what ever is by some, who have written of it, and
+particularly by _Francisco Stelluto_, wrote a Treatise in _Italian_ of that
+Subject, which was Printed at _Rome_, 1637, affirm'd that it is a certain
+kind of Clay or Earth, which in tract of time is turn'd into Wood; I rather
+suspect the quite contrary, that it was at first certain great Trees of Fir
+or Pine, which by some Earthquake, or other casualty, came to be buried
+under the Earth, and was there, after a long time's residence (according to
+the several natures of the encompassing adjacent parts) either rotted and
+turn'd into a kind of Clay, or _petrify'd_ and turn'd into a kind of Stone,
+or else had its pores fill'd with certain Mineral juices, which being
+stay'd in them, and in tract of time coagulated, appear'd, upon cleaving
+out, like small Metaline Wires, or else from some flames or scorching forms
+that are the occasion oftentimes, and usually accompany Earthquakes, might
+be blasted and turn'd into Coal, or else from certain _subterraneous_ fires
+which are affirm'd by that Authour to abound much about those parts
+(namely, in a Province of _Italy_, call'd _Umbria_, now the _Dutchie_ of
+_Spoletto_, in the Territory of _Todi_, anciently call'd _Tudor_; and
+between the two Villages of _Collesecco_ and _Rosaro_ not far distant from
+the high-way leading to _Rome_, where it is found in greater quantity then
+elsewhere) are by reason of their being encompassed with Earth, and so kept
+close from the dissolving Air, charr'd and converted into Coal. It would be
+too long a work to describe the several kinds of pores which I met withall,
+and by this means discovered in several other Vegetable bodies; nor is it
+my present design to expatiate upon Instances of the same kind, but rather
+to give a Specimen of as many kinds as I have had opportunity as yet of
+observing, reserving the prosecution and enlarging on particulars till a
+more fit opportunity; and in prosecution of this design, I shall here add:
+
+       *       *       *       *       *
+
+
+Observ. XVII. _Of _Petrify'd wood_, and other _Petrify'd bodies_._
+
+Of this sort of substance, I observ'd several pieces of very differing
+kinds, both for their outward shape, colour, grain, _texture_, hardness,
+&c. some being brown and redish; others gray, like a Hone; others black,
+and Flint-like: some soft, like a Slate or Whetstone, others as hard as a
+Flint, and as brittle. That which I more particular examin'd, was a piece
+about the bigness of a mans hand, which seem'd to have been a part of some
+large tree, that by rottenness had been broken off from it before it began
+to be _petrify'd_.
+
+And indeed, all that I have yet seen, seem to have been rotten Wood before
+the petrifaction was begun; and not long since, examining and viewing a
+huge great _Oak_, that seem'd with meer age to be rotten as it stood, I was
+very much confirm'd in this opinion; for I found, that the grain, colour,
+and shape of the Wood, was exactly like this _petrify'd_ substance; and
+with a _Microscope_, I found, that all those _Microscopical_ pores, which
+in sappy or firm and sound Wood are fill'd with the natural or innate
+juices of those Vegetables, in this they were all empty, like those of
+_Vegetables charr'd_; but with this difference, that they seem'd much
+larger then I have seen any in _Char-coals_; nay, even then those of Coals
+made of great blocks of Timber, which are commonly call'd _Old-coals_.
+
+The reason of which difference may probably be, that the charring of
+Vegetables, being an operation quickly perform'd, and whilest the Wood is
+sappy, the more solid parts may more easily shrink together, and contract
+the pores or _interstitia_ between them, then in the rotten Wood, where
+that natural juice seems onely to be wash'd away by _adventitious_ or
+unnatural moisture; and so though the natural juice be wasted from between
+the firm parts, yet those parts are kept asunder by the _adventitious_
+moystures, and so by degrees settled in those postures.
+
+And this I likewise found in the _petrify'd_ Wood, that the pores were
+somewat bigger then those of _Charcoal_, each pore being neer upon half as
+bigg again, but they did not bear that disproportion which is exprest in
+the tenth _Scheme_, between the small specks or pores in the first Figure
+(which representeth the pores of Coal or Wood charr'd) and the black spots
+of the second Figure (which represent the like _Microscopical pores_ in the
+_petrify'd_ Wood) for these last were drawn by a _Microscope_ that
+magnify'd the object above six times more in Diameter then the _Microscope_
+by which those pores of Coal were observ'd.
+
+Now, though they were a little bigger, yet did they keep the exact figure
+and order of the pores of Coals and of rotten Wood, which last also were
+much of the same cize.
+
+The other Observations on this _petrify'd_ substance, that a while since,
+by the appointment of the _Royal Society_, I made, and presented to them an
+account of, were these that follow, which had the honour done them by the
+most accomplish'd Mr. _Evelin_, my highly honoured friend, to be inserted
+and published among those excellent Observations wherewith his _Sylva_ is
+replenish'd, and would therefore have been here omitted, had not the Figure
+of them, as they appear'd through the _Microscope_ been before that
+engraven.
+
+This _Petrify'd_ substance resembled Wood, in that
+
+First, all the parts of it seem'd not at all _dislocated_, or alter'd from
+their natural Position, whil'st they were Wood, but the whole piece
+retain'd the exact shape of Wood, having many of the conspicuous pores of
+wood still remaining pores, and shewing a manifest difference visible
+enough between the grain of the Wood and that of the bark, especially when
+any side of it was cut smooth and polite; for then it appear'd to have a
+very lovely grain, like that of some curious close Wood.
+
+Next (it resembled Wood) in that all the smaller and (if I may so call
+those which are onely visible with a good magnifying Glass) _Microscopical_
+pores of it appear (both when the substance is cut and polish'd
+_transversly_ and _parallel_ to the pores of it) perfectly like the
+_Microscopical_ pores of several kinds of Wood, especially like and equal
+to those of several sorts of rotten Wood which I have since observ'd,
+retaining both the shape, position and magnitude of such pores. It was
+differing from Wood:
+
+First; in _weight_, being to common water as 3Πto 1. whereas there are few
+of our _English_ Woods, that when very dry are found to be full as heavie
+as water.
+
+Secondly, in _hardness_, being very neer as hard as a Flint; and in some
+places of it also resembling the grain of a Flint: and, like it, it would
+very readily cut Glass, and would not without difficulty, especially in
+some parts of it, be scratch'd by a black hard Flint: It would also as
+readily strike fire against a Steel, or against a Flint, as any common
+Flint.
+
+Thirdly, in the _closeness_ of it, for though all the _Microscopical_ pores
+of this _petrify'd_ substance were very conspicuous in one position, yet by
+altering that position of the polish'd surface to the light, it was also
+manifest, that those pores appear'd darker then the rest of the body, onely
+because they were fill'd up with a more duskie substance, and not because
+they were hollow.
+
+Fourthly, in its _incombustibleness_, in that it would not burn in the
+fire; nay, though I kept it a good while red-hot in the flame of a Lamp,
+made very _intense_ by the blast of a small Pipe, and a large Charcoal, yet
+it seem'd not at all to have diminish'd its extension; but only I found it
+to have chang'd its colour, and to appear of a more dark and duskie brown
+colour; nor could I perceive that those parts which seem'd to have been
+Wood at first, were any thing wasted, but the parts appear'd as solid and
+close as before. It was further observable also, that as it did not consume
+like Wood, so neither did it crack and flie like a Flint, or such like hard
+Stone, nor was it long before it appear'd red-hot.
+
+Fifthly, in its _dissolubleness_; for putting some drops of distill'd
+_Vinegar_ upon the Stone, I found it presently to yield very many Bubbles,
+just like those which may be observ'd in spirit of _Vinegar_ when it
+corrodes _corals_, though perhaps many of those small Bubbles might proceed
+from some small parcels of Air which were driven out of the pores of this
+_petrify'd_ substance by the insinuating liquid _menstruum_.
+
+Sixthly, in its _rigidness_, and _friability_, being not at all flexible
+but brittle like a Flint, insomuch that I could with one knock of a Hammer
+break off a piece of it, and with a few more, reduce that into a pretty
+fine powder.
+
+Seventhly, it seem'd also very differing from Wood to the _touch_,
+_feeling_ more cold then Wood usually does, and much like other close
+stones and Minerals.
+
+The Reasons of all which _Phænomena_ seem to be,
+
+That _petrify'd_ Wood having lain in some place where it was well soak'd
+with _petrifying_ water (that is, such a water as is well _impregnated_
+with stony and earthy particles) did by degrees separate, either by
+straining and _filtration_, or perhaps, by _precipitation_, _cohesion_ or
+_coagulation_, abundance of stony particles from the permeating water,
+which stony particles, being by means of the fluid _vehicle_ convey'd, not
+onely into the _Microscopical_ pores, and so perfectly stoping them up, but
+also into the pores or _interstitia_, which may, perhaps, be even in the
+texture or _Schematisme_ of that part of the Wood, which, through the
+_Microscope_, appears most solid, do thereby so augment the weight of the
+Wood, as to make it above three times heavier then water, and perhaps, six
+times as heavie as it was when Wood.
+
+Next, they thereby so lock up and fetter the parts of the Wood, that the
+fire cannot easily make them flie away, but the action of the fire upon
+them is onely able to _Char_ those parts, as it were, like a piece of Wood,
+if it be clos'd very fast up in Clay, and kept a good while red-hot in the
+fire, will by the heat of the fire be charr'd and not consum'd, which may,
+perhaps, also be somewhat of the cause, why the _petrify'd_ substance
+appear'd of a dark brown colour after it had been burnt.
+
+By this _intrusion_ of the _petrifying_ particles, this substance also
+becomes hard and _friable_; for the smaller pores of the Wood being
+perfectly wedg'd, and stuft up with those stony particles, the small parts
+of the Wood have no places or pores into which they may slide upon bending,
+and consequently little or no flexion or yielding at all can be caus'd in
+such a substance.
+
+The remaining particles likewise of the Wood among the stony particles, may
+keep them from cracking and flying when put into the fire, as they are very
+apt to do in a Flint.
+
+Nor is Wood the onely substance that may by this kind of _transmutation_ be
+chang'd into stone; for I my self have seen and examin'd very many kinds of
+substances, and among very credible Authours, we may meet with Histories of
+such _Metamorphoses_ wrought almost on all kind of substances, both
+_Vegetable_ and _Animal_, which Histories, it is not my business at
+present, either to relate, or _epitomise_, but only to set down some
+Observation I lately made on several kind of _petrify'd_ Shels, found about
+_Keinsham_, which lies within four or five miles of _Bristol_, which are
+commonly call'd _Serpentine-stones._
+
+Examining several of these very curiously figur'd bodies (which are
+commonly thought to be Stones form'd by some extraordinary _Plastick
+virtue_ _latent_ in the Earth itself) I took notice of these particulars:
+
+First, that these figured bodies, or stones, were of very differing
+substances, as to hardness: some of Clay, some Marle, some soft Stone,
+almost of the hardness of those soft stones which Masons call Fire-stone,
+others as hard as Portland stone, others as hard as Marble, and some as
+hard as a Flint or Crystal.
+
+Next, they were of very differing substances as to transparency and colour;
+some white, some almost black, some brown, some Metalline, or like
+Marchasites; some transparent like white Marble, others like flaw'd
+Crystal, some gray, some of divers colours; some radiated like those long
+_petrify'd drops_, which are commonly found at the _Peak_, and in other
+_subterraneous caverns_, which have a kind of pith in the middle.
+
+Thirdly, that they were very different as to the manner of their outward
+figuration; for some of them seem'd to have been the substance that had
+fill'd the Shell of some kind of Shel-fish; others, to have been the
+substance that had contain'd or enwrapp'd one of those Shels, on both
+which, the perfect impression either of the inside or outside of such
+Shells seem'd to be left, but for the most part, those impressions seem'd
+to be made by an imperfect or broken Shell, the great end or mouth of the
+Shell being always wanting, and often times the little end, and sometimes
+half, and in some there were impressions, just as if there had been holes
+broken in the figurating, imprinting or moulding Shell; some of them seem'd
+to be made by such a Shell very much brused or flaw'd, insomuch that one
+would verily have thought that very figur'd stone had been broken or brused
+whilst a gelly, as 'twere, and so hardned, but within in the grain of the
+stone, there appear'd not the least sign of any such bruse or breaking, but
+onely on the very uttermost superficies.
+
+Fourthly, they were very different, as to their outward covering, some
+having the perfect Shell, both in figure, colour, and substance, sticking
+on upon its surface, and adhering to it, but might very easily be separated
+from it, and like other common _Cockle_ or _Scolop-shels_, which some of
+them most accurately resembled, were very dissoluble in common _Vinegar_,
+others of them, especially those _Serpentine_, or _Helical stones_ were
+cover'd or retained the shining or Pearl-colour'd substance of the inside
+of a Shel, which substance, on some parts of them, was exceeding thin, and
+might very easily be rubbed off; on other parts it was pretty thick, and
+retained a white coat, or flaky substance on the top, just like the
+outsides of such Shells; some of them had very large pieces of the Shell
+very plainly sticking on to them, which were easily to be broken or flaked
+off by degrees: they likewise, some of them retain'd all along the surface
+of them very pretty kind of _sutures_, such as are observ'd in the skulls
+of several kinds of living creatures, which _sutures_ were most curiously
+shap'd in the manner of leaves, and every one of them in the same Shell,
+exactly one like another, which I was able to discover plainly enough with
+my naked eye, but more perfectly and distinctly with my _Microscope_; all
+these sutures, by breaking some of these stones, I found to be the
+_termini_, or boundings of certain _diaphragms_, or partitions, which
+seem'd to divide the cavity of the Shell into a multitude of very
+proportionate and regular _cells_ or _caverns_, these _Diaphragms_, in many
+of them, I found very perfect and compleat, of a very distinct substance
+from that which fill'd the cavities, and exactly of the same kind with that
+which covered the outside, being for the most part whitish, or
+_mother-of-pearl_ colour'd.
+
+As for the cavities between those _Diaphragms_, I found some of them fill'd
+with Marle, and others with several kinds of stones, others, for the most
+part hollow, onely the whole cavity was usually covered over with a kind of
+_tartareous petrify'd_ substance, which stuck about the sides, and was
+there shot into very curious regular Figures, just as _Tartar_, or other
+dissolv'd Salts are observ'd to stick and _crystallize_ about the sides of
+the containing Vessels; or like those little _Diamants_ which I before
+observed to have covered the vaulted cavity of a Flint; others had these
+cavities all lin'd with a kind of _metalline_ or _marchasite-like_
+substance, which with a _Microscope_ I could as plainly see most curiously
+and regularly figured, as I had done those in a Flint.
+
+From all which, and several other particulars which I observ'd, I cannot
+but think, that all these, and most other kinds of stony bodies which are
+found thus strangely figured, do owe their formation and figuration, not to
+any kind of _Plastick virtue_ inherent in the earth, but to the Shells of
+certain Shel-fishes, which, either by some Deluge, Inundation, Earthquake,
+or some such other means, came to be thrown to that place, and there to be
+fill'd with some kind of Mudd or Clay, or _petrifying_ Water, or some other
+substance, which in tract of time has been settled together and hardned in
+those shelly moulds into those shaped substances we now find them; that the
+great and thin end of these Shells by that Earthquake, or what ever other
+extraordinary cause it was that brought them thither, was broken off; and
+that many others were otherwise broken, bruised and disfigured; that these
+Shells which are thus _spirallied_ and separated with _Diaphragmes_, were
+some kind of _Nautili_ or _Porcelane shells_; and that others were shells
+of _Cockles_, _Muscles_, _Periwincles_, _Scolops_, &c. of various sorts;
+that these Shells in many, from the particular nature of the containing or
+enclos'd Earth, or some other cause, have in tract of time rotted and
+mouldred away, and onely left their impressions, both on the containing and
+contained substances; and so left them pretty loose one within another, so
+that they may be easily separated by a knock or two of a Hammer. That
+others of these Shells, according to the nature of the substances adjacent
+to them, have, by a long continuance in that posture, been _petrify'd_ and
+turn'd into the nature of stone, just as I even now observ'd several sorts
+of Wood to be. That oftentimes the Shell may be found with one kind of
+substance within, and quite another without; having, perhaps, been fill'd
+in one place, and afterwards translated to another, which I have very
+frequently observ'd in _Cockle_, _Muscle_, _Periwincle_, and other shells,
+which I have found by the Sea side. Nay, further, that some parts of the
+same Shell may be fill'd in one place, and some other caverns in another,
+and others in a third, or a fourth, or a fifth place, for so many differing
+substances have I found in one of these _petrify'd_ Shells, and perhaps all
+these differing from the encompassing earth or stone; the means how all
+which varieties may be caus'd, I think, will not be difficult to conceive,
+to any one that has taken notice of those Shells, which are commonly found
+on the Sea shore: And he that shall throughly examine several kinds of such
+curiously form'd stones, will (I am very apt to think) find reason to
+suppose their generation or formation to be ascribable to some such
+accidents as I have mention'd, and not to any _Plastick virtue_: For it
+seems to me quite contrary to the infinite prudence of Nature, which is
+observable in all its works and productions, to design every thing to a
+determinate end, and for the attaining of that end, makes use of such ways
+as are (as farr as the knowledge of man has yet been able to reach)
+altogether consonant, and most agreeable to man's reason, and of no way or
+means that does contradict, or is contrary to humane Ratiocination; whence
+it has a long time been a general observation and _maxime_, that _Nature
+does nothing in vain_; It seems, I say, contrary to that great Wisdom of
+Nature, that these prettily shap'd bodies should have all those curious
+Figures and contrivances (which many of them are adorn'd and contriv'd
+with) generated or wrought by a _Plastick virtue_, for no higher end, then
+onely to exhibite such a form; which he that shall throughly consider all
+the circumstances of such kind of Figur'd bodies, will, I think, have great
+reason to believe, though, I confess, one cannot presently be able to find
+out what Nature's designs are. It were therefore very desirable, that a
+good collection of such kind of figur'd stones were collected; and as many
+particulars, circumstances, and informations collected with them as could
+be obtained, that from such a History of Observations well rang'd, examin'd
+and digested, the true original or production of all those kinds of stones
+might be perfectly and surely known; such as are _Thunder-stones_, _Lapides
+Stellares_, _Lapides Judaici_, and multitudes of other, whereof mention is
+made in _Aldonandus_, _Wormius_, and other Writers of Minerals.
+
+       *       *       *       *       *
+
+
+Observ. XVIII. _Of the _Schematisme_ or _Texture_ of _Cork_, and of the
+Cells and Pores of some other such frothy Bodies._
+
+I took a good clear piece of Cork, and with a Pen-knife sharpen'd as keen
+as a Razor, I cut a piece of it off, and thereby left the surface of it
+exceeding smooth, then examining it very diligently with a _Microscope_, me
+thought I could perceive it to appear a little porous; but I could not so
+plainly distinguish them, as to be sure that they were pores, much less
+what Figure they were of: But judging from the lightness and yielding
+quality of the Cork, that certainly the texture could not be so curious,
+but that possibly, if I could use some further diligence, I might find it
+to be discernable with a _Microscope_, I with the same sharp Penknife, cut
+off from the former smooth surface an exceeding thin piece of it, and
+placing it on a black object Plate, because it was it self a white body,
+and casting the light on it with a deep _plano-convex Glass_, I could
+exceeding plainly perceive it to be all perforated and porous, much like a
+Honey-comb, but that the pores of it were not regular; yet it was not
+unlike a Honey-comb in these particulars.
+
+First, in that it had a very little solid substance, in comparison of the
+empty cavity that was contain'd between, as does more manifestly appear by
+the Figure A and B of the XI. _Scheme_, for the _Interstitia_, or walls (as
+I may so call them) or partitions of those pores were neer as thin in
+proportion to their pores, as those thin films of Wax in a Honey-comb
+(which enclose and constitute the _sexangular celts_) are to theirs.
+
+Next, in that these pores, or cells, were not very deep, but consisted of a
+great many little Boxes, separated out of one continued long pore, by
+certain _Diaphragms_, as is visible by the Figure B, which represents a
+sight of those pores split the long-ways.
+
+I no sooner discern'd these (which were indeed the first _microscopical_
+pores I ever saw, and perhaps, that were ever seen, for I had not met with
+any Writer or Person, that had made any mention of them before this) but me
+thought I had with the discovery of them, presently hinted to me the true
+and intelligible reason of all the _Phænomena_ of Cork; As,
+
+First, if I enquir'd why it was so exceeding light a body? my _Microscope_
+could presently inform me that here was the same reason evident that there
+is found for the lightness of froth, an empty Honey-comb, Wool, a Spunge, a
+Pumice-stone, or the like; namely, a very small quantity of a solid body,
+extended into exceeding large dimensions.
+
+Next, it seem'd nothing more difficult to give an intelligible reason, why
+Cork is a body so very unapt to suck and drink in Water, and consequently
+preserves it self, floating on the top of Water, though left on it never so
+long: and why it is able to stop and hold air in a Bottle, though it be
+there very much condens'd and consequently presses very strongly to get a
+passage out, without suffering the least bubble to pass through its
+substance. For, as to the first, since our _Microscope_ informs us that the
+substance of Cork is altogether fill'd with Air, and that that Air is
+perfectly enclosed in little Boxes or Cells distinct from one another. It
+seems very plain, why neither the Water, nor any other Air can easily
+insinuate it self into them, since there is already within them an _intus
+existens_, and consequently, why the pieces of Cork become so good floats
+for Nets, and stopples for Viols, or other close Vessels.
+
+And thirdly, if we enquire why Cork has such a springiness and swelling
+nature when compress'd? and how it comes to suffer so great a compression,
+or seeming penetration of dimensions, so as to be made a substance as
+heavie again and more, bulk for bulk, as it was before compression, and yet
+suffer'd to return, is found to extend it self again into the same space?
+Our _Microscope_ will easily inform us, that the whole mass consists of an
+infinite company of small Boxes or Bladders of Air, which is a substance of
+a springy nature, and that will suffer a considerable condensation (as I
+have several times found by divers trials, by which I have most evidently
+condens'd it into less then a twentieth part of its usual dimensions neer
+the Earth, and that with no other strength then that of my hands without
+any kind of forcing Engine, such as Racks, Leavers, Wheels, Pullies, or the
+like, but this onely by and by) and besides, it seems very probable that
+those very films or sides of the pores, have in them a springing quality,
+as almost all other kind of Vegetable substances have, so as to help to
+restore themselves to their former position.
+
+And could we so easily and certainly discover the _Schematisme_ and
+_Texture_ even of these films, and of several other bodies, as we can these
+of Cork; there seems no probable reason to the contrary, but that we might
+as readily render the true reason of all their _Phænomena_; as namely, what
+were the cause of the springingess, and toughness of some, both as to their
+flexibility and restitution. What, of the friability or brittleness of some
+others, and the like; but till such time as our _Microscope_, or some other
+means, enable us to discover the true _Schematism_ and _Texture_ of all
+kinds of bodies, we must grope, as it were, in the dark, and onely ghess at
+the true reasons of things by similitudes and comparisons.
+
+But, to return to our Observation. I told several lines of these pores, and
+found that there were usually about threescore of these small Cells placed
+end-ways in the eighteenth part of an Inch in length, whence I concluded
+there must be neer eleven hundred of them, or somewhat more then a thousand
+in the length of an Inch, and therefore in a square Inch above a Million,
+or 1166400. and in a Cubick Inch, above twelve hundred Millions, or
+1259712000. a thing almost incredible, did not our _Microscope_ assure us
+of it by ocular demonstration; nay, did it not discover to us the pores of
+a body, which were they _diaphragm'd_, like those of Cork, would afford us
+in one Cubick Inch, more then ten times as many little Cells, as is evident
+in several charr'd Vegetables; so prodigiously curious are the works of
+Nature, that even these conspicuous pores of bodies, which seem to be the
+channels or pipes through which the _Succus nutritius_, or natural juices
+of Vegetables are convey'd, and seem to correspond to the veins, arteries
+and other Vessels in sensible creatures, that these pores I say, which seem
+to be the Vessels of nutrition to the vastest body in the World, are yet so
+exceeding small, that the _Atoms_ which _Epicurus_ fancy'd would go neer to
+prove too bigg to enter them, much more to constitute a fluid body in them.
+And how infinitely smaller then must be the Vessels of a Mite, or the pores
+of one of those little Vegetables I have discovered to grow on the
+back-side of a Rose-leaf, and shall anon more fully describe, whose bulk is
+many millions of times less then the bulk of the small shrub it grows on;
+and even that shrub, many millions of times less in bulk then several trees
+(that have heretofore grown in _England_, and are this day flourishing in
+other hotter Climates, as we are very credibly inform'd) if at least the
+pores of this small Vegetable should keep any such proportion to the body
+of it, as we have found these pores of other Vegetables to do to their
+bulk. But of these pores I have said more elsewhere.
+
+To proceed then, Cork seems to be by the transverse constitution of the
+pores, a kind of _Fungus_ or Mushrome, for the pores lie like so many Rays
+tending from the center, or pith of the tree, outwards; so that if you cut
+off a piece from a board of Cork transversly, to the flat of it, you will,
+as it were, split the pores, and they will appear just as they are
+express'd in the Figure B of the XI. _Scheme_. But if you shave off a very
+thin piece from this board, parallel to the plain of it, you will cut all
+the pores transversly, and they will appear almost as they are express'd in
+the Figure A, save onely the solid _Interstitia_ will not appear so thick
+as they are there represented.
+
+So that Cork seems to suck its nourishment from the subjacent bark of the
+Tree immediately, and to be a kind of excrescence, or a substance distinct
+from the substances of the entire Tree, something _analogus_ to the
+Mushrome, or Moss on other Trees, or to the hairs on Animals. And having
+enquir'd into the History of Cork, I find it reckoned as an excrescency of
+the bark of a certain Tree, which is distinct from the two barks that lie
+within it, which are common also to other trees; That 'tis some time before
+the Cork that covers the young and tender sprouts comes to be discernable;
+That it cracks, flaws, and cleaves into many great chaps, the bark
+underneath remaining entire; That it may be separated and remov'd from the
+Tree, and yet the two under-barks (such as are also common to that with
+other Trees) not at all injur'd, but rather helped and freed from an
+external injury. Thus _Jonstonus_ in _Dendrologia_, speaking _de Subere_,
+says, _Arbor est procera, Lignum est robustum, dempto cortice in aquis non
+fluitat, Cortice in orbem detracto juvatur, crascescens enim præstringit &
+strangulat, intra triennium iterum repletur: Caudex ubi adolescit crassus,
+cortex superior densus carnosus, duos digitos crassus, scaber, rimosus, &
+qui nisi detrahatur dehiscit, alioque subnascente expellitur, interior qui
+subest novellus ita rubet ut arbor minio picta videatur_. Which Histories,
+if well consider'd, and the tree, substance, and manner of growing, if well
+examin'd, would, I am very apt to believe, much confirm this my conjecture
+about the origination of Cork.
+
+Nor is this kind of Texture peculiar to Cork onely; for upon examination
+with my _Microscope_, I have found that the pith of an Elder, or almost any
+other Tree, the inner pulp or pith of the Cany hollow stalks of several
+other Vegetables: as of Fennel, Carrets, Daucus, Bur-docks, Teasels, Fearn,
+some kinds of Reeds, &c. have much such a kind of _Schematisme_, as I have
+lately shewn that of Cork, save onely that here the pores are rang'd the
+long-ways, or the same ways with the length of the Cane, whereas in Cork
+they are transverse.
+
+The pith also that fills that part of the stalk of a Feather that is above
+the Quil, has much such a kind of texture, save onely that which way soever
+I set this light substance, the pores seem'd to be cut transversly; so that
+I ghess this pith which fills the Feather, not to consist of abundance of
+long pores separated with Diaphragms, as Cork does, but to be a kind of
+solid or hardned froth, or a _congeries_ of very small bubbles consolidated
+in that form, into a pretty stiff as well as tough concrete, and that each
+Cavern, Bubble, or Cell, is distinctly separate from any of the rest,
+without any kind of hole in the encompassing films, so that I could no more
+blow through a piece of this kinde of substance, then I could through a
+piece of Cork, or the sound pith of an Elder.
+
+But though I could not with my _Microscope_, nor with my breath, nor any
+other way I have yet try'd, discover a passage out of one of those cavities
+into another, yet I cannot thence conclude, that therefore there are none
+such, by which the _Succus nutritius_, or appropriate juices of Vegetables,
+may pass through them; for, in several of those Vegetables, whil'st green,
+I have with my _Microscope_, plainly enough discover'd these Cells or Poles
+fill'd with juices, and by degrees sweating them out; as I have also
+observed in green Wood all those long _Microscopical_ pores which appear in
+Charcoal perfectly empty of any thing but Air.
+
+Now, though I have with great diligence endeavoured to find whether there
+be any such thing in those _Microscopical_ pores of Wood or Piths, as the
+_Valves_ in the heart, veins, and other passages of Animals, that open and
+give passage to the contain'd fluid juices one way, and shut themselves,
+and impede the passage of such liquors back again, yet have I not hitherto
+been able to say any thing positive in it; though, me thinks, it seems very
+probable, that Nature has in these passages, as well as in those of Animal
+bodies, very many appropriated Instruments and contrivances, whereby to
+bring her designs and end to pass, which 'tis not improbable, but that some
+diligent Observer, if help'd with better _Microscopes_, may in time detect.
+
+And that this may be so, seems with great probability to be argued from the
+strange _Phænomena_ of sensitive Plants, wherein Nature seems to perform
+several Animal actions with the same _Schematism_ or _Orginization_ that is
+common to all Vegetables, as may appear by some no less instructive then
+curious Observations that were made by divers Eminent Members of the _Royal
+Society_ on some of these kind of Plants, whereof an account was delivered
+in to them by the most Ingenious and Excellent _Physician_, Doctor _Clark_,
+which, having that liberty granted me by that most Illustrious Society, I
+have hereunto adjoyn'd.
+
+_Observations on the _Humble_ and _Sensible Plants_ in _M Chiffin's_ Garden
+in Saint _James_'s Park, made _August_ the _9th, 1661_._ _Present, the_
+Lord _Brouncker_, Sr. _Robert Moray_, Dr. _Wilkins_, Mr. _Evelin_, Dr.
+_Henshaw_, _and_ Dr. _Clark_.
+
+    There are four Plants, two of which are little shrub Plants, with a
+    little short stock, about an Inch above the ground, from whence are
+    spread several sticky branches, round, streight, and smooth in the
+    distances between the Sprouts, but just under the Sprouts there are two
+    sharp thorny prickles, broad in the letting on, as in the Bramble, one
+    just under the Sprout, the other on the opposite side of the branch.
+
+    [14]The distances betwixt the Sprouts are usually something more then
+    an Inch, and many upon a Branch, according to its length, and they grew
+    so, that if the lower Sprout be on the left side of the Branch, the
+    next above is on the right, and so to the end, not sprouting by pairs.
+
+    At the end of each Sprout are generally four sprigs, two at the
+    Extremity, and one on each side, just under it. At the first sprouting
+    of these from the Branch to the Sprig where the leaves grow, they are
+    full of little short white hairs, which wear off as the leaves grow,
+    and then they are smooth as the Branch.
+
+    Upon each of these sprigs, are, for the most part, eleven pair of
+    leaves, neatly set into the uppermost part of the little sprig, exactly
+    one against another, as it were in little _articulations_, such as
+    Anatomists call _Enarthrosis_, where the round head of a Bone is
+    received into another fitted for its motion; and standing very fitly to
+    shut themselves and touch, the pairs just above them closing somewhat
+    upon them, as in the shut sprig; so is the little round _Pedunculus_ of
+    this leaf fitted into a little cavity of the sprig, visible to the eye
+    in a sprig new pluck'd, or in a sprig withered on the Branch, from
+    which the leaves easily fall by touching.
+
+    The leaf being almost an oblong square, and set into the _Pedunculus_,
+    at one of the lower corners, receiveth from that not onely a _Spine_,
+    as I may call it, which, passing through the leaf, divides it so
+    length-ways that the outer-side is broader then the inner next the
+    sprig, but little _fibres_ passing obliquely towards the opposite
+    broader side, seem to make it here a little muscular, and fitted to
+    move the whole leaf, which, together with the whole sprig, are set full
+    with little short whitish hairs.
+
+    One of these Plants, whose branch seem'd to be older and more grown
+    then the other, onely the tender Sprouts of it, after the leaves are
+    shut, fall and hang down; of the other, the whole branches fall to the
+    ground, if the Sun shine very warm, upon the first taking off the
+    Glass, which I therefore call the _humble Plant_.
+
+    The other two, which do never fall, nor do any of their branches flagg
+    and hang down, shut not their leaves, but upon somewhat a hard stroke;
+    the stalks seem to grow up from a root, and appear more _herbaceous_,
+    they are round and smooth, without any prickle, the Sprouts from them
+    have several pairs of sprigs, with much less leaves then the other on
+    them, and have on each sprig generally seventeen pair.
+
+    Upon touching any of the sprigs with leaves on, all the leaves on that
+    sprig contracting themselves by pairs, joyned their upper superficies
+    close together.
+
+    Upon the dropping a drop of _Aqua fortis_ on the sprig betwixt the
+    leaves, ff all the leaves above shut presently, those below by pairs
+    successively after, and by the lower leaves of the other branches, ll,
+    kk, &c. and so every pair successively, with some little distance of
+    time betwixt, to the top of each sprig, and so they continu'd shut all
+    the time we were there. But I returning the next day, and several days
+    since, found all the leaves dilated again on two of the sprigs; but
+    from ff, where the _Aqua fortis_ had dropped upwards, dead and
+    withered; but those below on the same sprig, green, and closing upon
+    the touch, and are so to this day, _August_ 14.
+
+    With a pair of Scissers, as suddenly as it could be done, one of the
+    leaves bb was clipped off in the middle, upon which that pair, and the
+    pair above, closed presently, after a little interval, dd, then ee, and
+    so the rest of the pairs, to the bottom of the sprig, and then the
+    motion began in the lower pairs, ll, on the other sprigs, and so shut
+    them by pairs upwards, though not with such distinct distances.
+
+    Under a pretty large branch with its sprigs on, there lying a large
+    Shell betwixt two and three Inches below it, there was rubbed on a
+    strong sented oyl, after a little time all the leaves on that sprig
+    were shut, and so they continued all the time of our stay there, but at
+    my returne the next day, I found the position of the Shell alter'd, and
+    the leaves expanded as before, and closing upon the touch.
+
+    Upon the application of the Sun-beams by a Burning-glass, the more
+    _humble Plant_ fell, the other shut their leaves.
+
+    We could not so apply the smoak of _Sulpher_, as to have any visible
+    effect from that, at two or three times trial; but on another trial,
+    the smoak touching the leaves, it succeeded.
+
+    The _humble Plant_ fell upon taking off the Glass wherewith it was
+    covered.
+
+    Cutting off one of the little Sprouts, two or three drops of liquor
+    were thrust out of the part from whence that was cut, very cleer, and
+    pellucid, of a bright greenish colour, tasting at first a little
+    bitterish, but after leaving a licorish-like taste in my mouth.
+
+    Since, going two or three times when it was cold, I took the Glasses
+    from the more _humble Plant_, and it did not fall as formerly, but shut
+    its leaves onely. But coming afterwards, when the Sun shone very warm,
+    as soon as it was taken off, it fell as before.
+
+    Since I pluck'd off another sprig, whose leaves were all shut, and had
+    been so some time, thinking to observe the liquor should come from that
+    I had broken off, but finding none, though with pressing, to come, I,
+    as dexterously as I could, pull'd off one whose leaves were expanded,
+    and then had upon the shutting of the leaves, a little of the mention'd
+    liquor, from the end of the sprig I had broken from the Plant. And this
+    twice successively, as often almost as I durst rob the Plant.
+
+    But my curiosity carrying me yet further, I cut off one of the harder
+    branches of the stronger Plant, and there came of the liquor, both from
+    that I had cut, and that I had cut it from, without pressure.
+
+    Which made me think, that the motion of this Plant upon touching, might
+    be from this, that there being a constant _intercourse_ betwixt every
+    part of this Plant and its root, either by a _circulation_ of this
+    liquor, or a constant pressing of the subtiler parts of it to every
+    extremity of the Plant. Upon every pressure, from whatsoever it
+    proceeds, greater then that which keeps it up, the subtile parts of
+    this liquor are thrust downwards, towards its _articulations_ of the
+    leaves, where, not having room presently to get into the sprig, the
+    little round _pedunculus_, from whence the _Spine_ and those oblique
+    _Fibres_ I mentioned rise, being dilated, the _Spine_ and _Fibres_
+    (being continued from it) must be contracted and shortned, and so draw
+    the leaf upwards to joyn with its fellow in the same condition with it
+    self, where, being closed, they are held together by the implications
+    of the little whitish hair, as well as by the still retreating liquor,
+    which distending the _Fibres_ that are continued lower to the branch
+    and root, shorten them above; and when the liquor is so much forced
+    from the Sprout, whose _Fibres_ are yet tender, and not able to support
+    themselves, but by that tensness which the liquor filling their
+    _interstices_ gives them, the Sprout hangs and flags.
+
+    But, perhaps, he that had the ability and leisure to give you the exact
+    _Anatomy_ of this pretty Plant, to shew you its _Fibres_, and visible
+    _Canales_, through which this fine liquor circulateth, or is moved, and
+    had the faculty of better and more copiously expressing his
+    Observations and conceptions, such a one would easily from the motion
+    of this liquor, solve all the _Phænomena_, and would not fear to
+    affirm, that it is no obscure sensation this Plant hath. But I have
+    said too much, I humbly submit, and am ready to stand corrected.
+
+I have not yet made so full and satisfactory Observations as I desire on
+this Plant, which seems to be a Subject that will afford abundance of
+information. But as farr as I have had opportunity to examine it, I have
+discovered with my _Microscope_ very curious structures and contrivances;
+but designing much more accurate examinations and trials, both with my
+_Microscope_, and otherwise, as soon as the season will permit, I shall not
+till then add any thing of what I have already taken notice of; but as farr
+as I have yet observ'd, I judge the motion of it to proceed from causes
+very differing from those by which Gut-strings, or Lute-strings, the beard
+of a wilde _Oat_, or the beard of the Seeds of _Geranium_, _Mosscatum_, or
+_Musk-grass_ and other kinds of _Cranes-bill_, move themselves. Of which I
+shall add more in the subsequent Observations on those bodies.
+
+       *       *       *       *       *
+
+
+Observ. XIX. _Of a _Plant_ growing in the blighted or yellow specks of
+_Damask-rose-leaves_, _Bramble-leaves_, and some other kind of leaves._
+
+I have for several years together, in the Moneths of _June_, _July_,
+_August_, and _September_ (when any of the green leaves of _Roses_ begin to
+dry and grow yellow) observ'd many of them, especially the leaves of the
+old shrubs of _Damask Roses_, all bespecked with yellow stains; and the
+undersides just against them, to have little yellow hillocks of a gummous
+substance, and several of them to have small black spots in the midst of
+those yellow ones, which, to the naked eye, appear'd no bigger then the
+point of a Pin, or the smallest black spot or tittle of Ink one is able to
+make with a very sharp pointed Pen.
+
+Examining these with a _Microscope,_ I was able plainly to distinguish, up
+and down the surface, several small yellow knobs, of a kind of yellowish
+red gummy substance, out of which I perceiv'd there sprung multitudes of
+little cases or black bodies like Seed-cods, and those of them that were
+quite without the hillock of Gumm, disclos'd themselves to grow out of it
+with a small Straw-colour'd and transparent stem, the which seed and stem
+appear'd very like those of common Moss (which I elsewhere describe) but
+that they were abundantly less, many hundreds of them being not able to
+equalize one single seed Cod of Moss.
+
+I have often doubted whether they were the seed Cods of some little Plant,
+or some kind of small Buds, or the Eggs of some very small Insect, they
+appear'd of a dark brownish red, some almost quite black, and of a Figure
+much resembling the seed-cod of Moss, but their stalks on which they grew
+were of a very fine transparent substance, almost like the stalk of mould,
+but that they seem'd somewhat more yellow.
+
+That which makes me to suppose them to be Vegetables, is for that I
+perceiv'd many of those hillocks bare or destitute, as if those bodies lay
+yet conceal'd, as G. In others of them, they were just springing out of
+their gummy hillocks, which all seem'd to shoot directly outwards, as at A.
+In others, as at B, I found them just gotten out, with very little or no
+stalk, and the Cods of an indifferent cize; but in others, as C, I found
+them begin to have little short stalks, or stems; in others, as D, those
+stems were grown bigger, and larger; and in others, as at E, F, H, I, K, L,
+&c. those stems and Cods were grown a great deal bigger, and the stalks
+were more bulky about the root, and very much taper'd towards the top, as
+at F and L is most visible.
+
+I did not find that any of them had any seed in them, or that any of them
+were hollow, but as they grew bigger and bigger, I found those heads or
+Cods begin to turn their tops towards their roots, in the same manner as I
+had observ'd that of Moss to do; so that in all likelihood, Nature did
+intend in that posture, what she does in the like seed-cods of greater
+bulk, that is, that the seed, when ripe, should be shaken out and dispersed
+at the end of it, as we find in Columbine Cods, and the like.
+
+The whole Oval OOOO in the second _Figure_ of the 12. _Scheme_ represents a
+small part of a Rose leaf, about the bigness of the little Oval in the
+hillock, C, marked with the Figure X. in which I have not particularly
+observ'd all the other forms of the surface of the Rose-leaf, as being
+little to my present purpose.
+
+Now, if these Cods have a seed in them so proportion'd to the Cod, as thole
+of _Pinks_, and _Carnations_, and _Columbines_, and the like, how
+unimaginably small must each of those seeds necessarily be, for the whole
+length of one of the largest of those Cods was not 1/500 part of an Inch;
+some not above 1/1000, and therefore certainly, very many thousand of them
+would be unable to make a bulk that should be visible to the naked eye; and
+if each of these contain the Rudiments of a young Plant of the same kind,
+what must we say of the pores and constituent parts of that?
+
+The generation of this Plant seems in part, ascribable to a kind of
+_Mildew_ or _Blight_, whereby the parts of the leaves grow scabby, or
+putrify'd, as it were, so as that the moisture breaks out in little scabs
+or spots, which, as I said before, look like little knobs of a red gummous
+substance.
+
+From this putrify'd scabb breaks out this little Vegetable; which may be
+somewhat like a _Mould_ or _Moss_; and may have its _equivocal_ generation
+much after the same manner as I have supposed _Moss_ or _Mould_ to have,
+and to be a more simple and uncompounded kind of vegetation, which is set a
+moving by the _putrifactive_ and _fermentative_ heat, joyn'd with that of
+the ambient aerial, when (by the putrifaction and decay of some other parts
+of the vegetable, that for a while staid its progress) it is unfetter'd and
+left at liberty to move in its former course, but by reason of its
+_regulators_, moves and acts after quite another manner then it did when a
+_coagent_ in the more compounded _machine_ of the more perfect Vegetable.
+
+And from this very same Principle, I imagine the _Misleto_ of Oaks, Thorns,
+Appletrees, and other Trees, to have its original: It seldom or never
+growing on any of those Trees, till they begin to wax decrepid, and decay
+with age, and are pester'd with many other infirmities.
+
+Hither also may be referr'd those multitudes and varieties of _Mushroms_,
+such as that, call'd _Jews-ears_, all sorts of _gray_ and _green_ Mosses,
+&c. which infest all kind of Trees, shrubs, and the like, especially when
+they come to any bigness. And this we see to be very much the method of
+Nature throughout its operations, _putrifactive Vegetables_ very often
+producing a Vegetable of a much less compounded nature, and of a much
+inferiour tribe; and _putrefactive_ animal substances degenerating into
+some kind of animal production of a much inferiour rank, and of a more
+simple nature.
+
+Thus we find the humours and substances of the body, upon _putrifaction_,
+to produce strange kinds of moving Vermine: _the putrifaction_ of the
+slimes and juices of the Stomack and Guts, produce Worms almost like
+Earth-worms, the Wheals in childrens hands produce a little Worm, call'd a
+_Wheal-worm_: The bloud and milk, and other humours, produce other kinds of
+Worms, at least, if we may believe what is deliver'd to us by very famous
+Authors; though, I confess, I have not yet been able to discover such my
+self.
+
+And whereas it may seem strange that _Vinegar_, _Meal_, musty _Casks_, &c.
+are observ'd to breed their differing kinds of Insects, or living
+creatures, whereas they being Vegetable substances, seem to be of an
+inferiour kind, and so unable to produce a creature more noble, or of a
+more compounded nature then they themselves are of, and so without some
+concurrent seminal principle, may be thought utterly unfit for such an
+operation; I must add, that we cannot presently positively say, there are
+no animal substances, either mediately, as by the soil or fatning of the
+Plant from whence they sprung, or more immediately, by the real mixture or
+composition of such substances, join'd with them; or perchance some kind of
+Insect, in such places where such kind of _putrifying_ or _fermenting_
+bodies are, may, by a certain instinct of nature, eject some sort of
+seminal principle, which cooperating with various kinds of _putrifying_
+substances, may produce various kinds of Insects, or Animate bodies: For we
+find in most sorts of those lower degrees of Animate bodies, that the
+_putrifying_ substances on which these Eggs, Seeds, or seminal principles
+are cast by the Insect, become, as it were, the _Matrices_ or Wombs that
+conduce very much to their generation, and may perchance also to their
+variation and alteration, much after the same manner, as, by strange and
+unnatural copulations, several new kinds of Animals are produc'd, as
+_Mules_, and the like, which are usually call'd Monstrous, because a little
+unusual, though many of them have all their principal parts as perfectly
+shap'd and adapted for their peculiar uses, as any of the most perfect
+Animals. If therefore the _putrifying_ body, on which any kind of seminal
+or vital principle chances to be cast, become somewhat more then meerly a
+nursing and fostering helper in the generation and production of any kind
+of Animate body, the more neer it approaches the true nature of a Womb, the
+more power will it have on the by-blow it incloses. But of this somewhat
+more in the description of the _Water-gnat_. Perhaps some more accurate
+Enquiries and Observations about these matters might bring the Question to
+some certainty, which would be of no small concern in Natural Philosophy.
+
+But that _putrifying_ animal substances may produce animals of an inferior
+kind, I see not any so very great a difficulty, but that one may, without
+much absurdity, admit: For as there may be multitudes of contrivances that
+go to the making up of one compleat Animate body; so, That some of those
+_coadjutors_, in the perfect existence and life of it, may be vitiated, and
+the life of the whole destroyed, and yet several of the constituting
+contrivances remain intire, I cannot think it beyond imagination or
+possibility; no more then that a like accidental process, as I have
+elswhere hinted, may also be supposed to explicate the method of Nature in
+the _Metamorphosis_ of Plants. And though the difference between a Plant
+and an Animal be very great, yet I have not hitherto met with any so
+_cogent_ an Argument, as to make me positive in affirming these two to be
+altogether _Heterogeneous_ and of quite differing kinds of Nature: And
+besides, as there are many _Zoophyts_, and sensitive Plants (divers of
+which I have seen, which are of a middle nature, and seem to be Natures
+transition from one degree to another, which may be observ'd in all her
+other passages, wherein she is very seldom observ'd to leap from one step
+to another) so have we, in some Authors, Instances of Plants turning into
+Animals, and Animals into Plants, and the like; and some other very strange
+(because unheeded) proceedings of Nature; something of which kind may be
+met with, in the description of the _Water-Gnat_, though it be not
+altogether so direct to the present purpose.
+
+But to refer this Discourse of Animals to their proper places, I shall add,
+that though one should suppose, or it should be prov'd by Observations;
+that several of these kinds of Plants are accidentally produc'd by a casual
+_purifaction_, I see not any great reason to question, but that,
+notwithstanding its own production was as 'twere casual, yet it may
+germinate and produce seed, and by it propagate its own, that is, a new
+Species. For we do not know, but that the Omnipotent and All-wise Creator
+might as directly design the structure of such a Vegetable, or such an
+Animal to be produc'd out of such or such a _putrifaction_ or change of
+this or that body, towards the constitution or structure of which, he knew
+it necessary, or thought it fit to make it an ingredient; as that the
+digestion or moderate heating of an Egg, either by the Female, or the Sun,
+or the heat of the Fire, or the like, should produce this or that Bird; or
+that _Putrifactive_ and warm steams should, out of the blowings, as they
+call them, that is, the Eggs of a Flie, produce a living Magot, and that,
+by degrees, be turn'd into an _Aurelia_, and that, by a longer and a
+proportion'd heat, be _transmuted_ into a Fly. Nor need we therefore to
+suppose it the more imperfect in its kind, then the more compounded
+Vegetable or Animal of which it is a part; for he might as compleatly
+furnish it with all kinds of contrivances necessary for its own existence,
+and the propagation of its own Species, and yet make it a part of a more
+compounded body: as a Clock-maker might make a Set of Chimes to be a part
+of a Clock, and yet, when the watch part or striking part are taken away,
+and the hindrances of its motion remov'd, this chiming part may go as
+accurately, and strike its tune as exactly, as if it were still a part of
+the compounded _Automaton_. So, though the original cause, or seminal
+principle from which this minute Plant on Rose leaves did spring; were,
+before the corruption caus'd by the Mill-dew, a component part of the leaf
+on which it grew, and did serve as a _coagent_ in the production and
+constitution of it, yet might it be so consummate, as to produce a seed
+which might have a power of propagating the same species: the works of the
+Creator seeming of such an excellency, that though they are unable to help
+to the perfecting of the more compounded existence of the greater Plant or
+Animal, they may have notwithstanding an ability of acting singly upon
+their own internal principle, so as to produce a Vegetable body, though of
+a less compounded nature, and to proceed so farr in the method of other
+Vegetables, as to bear flowers and seeds, which may be capabale of
+propagating the like. So that the little cases which appear to grow on the
+top of the slender stalks, may, for ought I know, though I should suppose
+them to spring from the perverting of the usual course of the parent
+Vegetable, contain a seed, which, being scatter'd on other leaves of the
+same Plant, may produce a Plant of much the same kind.
+
+Nor are Damask-Rose leaves the onely leaves that produce these kinds of
+Vegetable sproutings; for I have observ'd them also in several other kinds
+of Rose leaves, and on the leaves of several sorts of Briers, and on
+Bramble leaves they are oftentimes to be found in very great clusters; so
+that I have found in one cluster, three, four, or five hundred of them,
+making a very conspicuous black spot or scab on the back side of the leaf.
+
+       *       *       *       *       *
+
+
+Observ. XX. _Of _blue Mould_, and of the first Principles of Vegetation
+arising from _Putrefaction_._
+
+The Blue and White and several kinds of hairy mouldy spots, which are
+observable upon divers kinds of _putrify'd_ bodies, whether Animal
+substances, or Vegetable, such as the skin, raw or dress'd, flesh, bloud,
+humours, milk, green Cheese, &c. or rotten sappy Wood, or Herbs, Leaves,
+Barks, Roots, &c. of Plants, are all of them nothing else but several kinds
+of small and variously figur'd Mushroms, which, from convenient materials
+in those _putrifying_ bodies, are, by the concurrent heat of the Air,
+excited to a certain kind of vegetation, which will not be unworthy our
+more serious speculation and examination, as I shall by and by shew. But,
+first, I must premise a short description of this _Specimen_, which I have
+added of this Tribe, in the first Figure of the XII. _Scheme_, which is
+nothing else but the appearance of a small white spot of hairy mould,
+multitudes of which I found to bespeck & whiten over the red covers of a
+small book, which, it seems, were of Sheeps skin, that being more apt to
+gather mould, even in a dry and clean room, then other leathers. These
+spots appear'd, through a good _Microscope_, to be a very pretty shap'd
+Vegetative body, which, from almost the same part of the Leather, shot out
+multitudes of small long cylindrical and transparent stalks, not exactly
+streight, but a little bended with the weight of a round and white knob
+that grew on the top of each of them; many of these knobs I observ'd to be
+very round, and of a smooth surface, such as A, A, &c. others smooth
+likewise, but a little oblong, as B; several of them a little broken, or
+cloven with chops at the top, as C; others flitter'd as 'twere, or flown
+all to pieces, as D, D. The whole substance of these pretty bodies was of a
+very tender constitution, much like the substance of the softer kind of
+common white Mushroms, for by touching them with a Pin, I found them to be
+brused and torn; they seem'd each of them to have a distinct root of their
+own; for though they grew neer together in a cluster, yet I could perceive
+each stem to rise out of a distinct part or pore of the Leather; some of
+these were small and short, as seeming to have been but newly sprung up, of
+these the balls were for the most part round, others were bigger, and
+taller, as being perhaps of a longer growth, and of these, for the most
+part, the heads were broken, and some much wasted, as E; what these heads
+contain'd I could not perceive; whether they were knobs and flowers, or
+seed cases, I am not able to say, but they seem'd most likely to be of the
+same nature with those that grow on Mushroms, which they did, some of them,
+not a little resemble.
+
+Both their smell and taste, which are active enough to make a sensible
+impression upon those organs, are unpleasant and noisome.
+
+I could not find that they would so quickly be destroy'd by the actual
+flame of a Candle, as at first sight of them I conceived they would be, but
+they remain'd intire after I had past that part of the Leather on which
+they stuck three or four times through the flame of a Candle; so that, it
+seems they are not very apt to take fire, no more then the common white
+Mushroms are when they are sappy.
+
+There are a multitude of other shapes, of which these _Microscopical_
+Mushroms are figur'd, which would have been a long Work to have described,
+and would not have suited so well with my design in this Treatise, onely,
+amongst the rest, I must not forget to take notice of one that was a little
+like to, or resembled, a Spunge, consisting of a multitude of little
+Ramifications almost as that body does, which indeed seems to be a kind of
+Water-Mushrom, of a very pretty texture, as I else-where manifest. And a
+second, which I must not omit, because often mingled, and neer adjoining to
+these I have describ'd, and this appear'd much like a Thicket of bushes, or
+brambles, very much branch'd, and extended, some of them, to a great
+length, in proportion to their Diameter, like creeping brambles.
+
+The manner of the growth and formation of this kind of Vegetable, is the
+third head of Enquiry, which, had I time, I should follow: the figure and
+method of Generation in this concrete seeming to me, next after the Enquiry
+into the formation, figuration; or chrystalization of Salts, to be the most
+simple, plain, and easie; and it seems to be a _medium_ through which he
+must necessarily pass, that would with any likelihood investigate the
+_forma informans_ of Vegetables: for as I think that he shall find it a
+very difficult task, who undertakes to discover the form of Saline
+crystallizations, without the consideration and prescience of the nature
+and reason of a Globular form, and as difficult to explicate this
+configuration of Mushroms, without the previous consideration of the form
+of Salts; so will the enquiry into the forms of Vegetables be no less, if
+not much more difficult, without the fore-knowledge of the forms of
+Mushroms, these several Enquiries having no less dependance one upon
+another then any select number of Propositions in Mathematical Elements may
+be made to have.
+
+Nor do I imagine that the skips from the one to another will be found very
+great, if beginning from fluidity, or body without any form, we descend
+gradually, till we arrive at the highest form of a bruite Animal's Soul,
+making the steps or foundations of our Enquiry, _Fluidity_, _Orbiculation_,
+_Fixation_, _Angulization_, or _Crystallization Germination_ or
+_Ebullition_, _Vegetation_, _Plantanimation_, _Animation_, _Sensation_,
+_Imagination_.
+
+Now, that we may the better proceed in our Enquiry, It will be requisite to
+consider:
+
+First, that Mould and Mushroms require no seminal property, but the former
+may be produc'd at any time from any kind of _putrifying_ Animal, or
+Vegetable Substance, as Flesh, &c. kept moist and warm, and the latter, if
+what _Mathiolus_ relates be true, of making them by Art, are as much within
+our command, of which Matter take the _Epitomie_ which Mr. _Parkinson_ has
+deliver'd in his _Herbal_, in his Chapter of _Mushroms_, because I have not
+_Mathiolus_ now by me: _Unto these Mushroms_ (saith he) _may also be
+adjoyn'd those which are made of Art (whereof _Mathiolus_ makes mention)
+that grow naturally among certain stones in _Naples_, and that the stones
+being digg'd up, and carried to _Rome_, and other places, where they set
+them in their Wine Cellars, covering them with a little Earth, and
+sprinkling a little warm water thereon, would within four days produce
+Mushroms fit to be eaten, at what time one will: As also that Mushroms may
+be made to grow at the foot of a wilde _Poplar Tree_, within four days
+after, warm water wherein some leaves have been dissolv'd shall be pour'd
+into the Root (which must be slit) and the stock above ground._
+
+Next, that as Mushroms may be generated without seed, so does it not appear
+that they have any such thing as seed in any part of them; for having
+considered several kinds of them, I could never find any thing in them that
+I could with any probability ghess to be the seed of it, so that it does
+not as yet appear (that I know of) that Mushroms may be generated from a
+seed, but they rather seem to depend merely upon a convenient constitution
+of the matter out of which they are made, and a concurrence of either
+natural or artificial heat.
+
+Thirdly, that by several bodies (as Salts and Metals both in Water and in
+the air, and by several kinds of sublimations in the Air) actuated and
+guided with a congruous heat, there may be produc'd several kinds of bodies
+as curiously, if not of a more compos'd Figure; several kinds of rising or
+Ebulliating Figures seem to manifest; as witness the shooting in the
+Rectification of spirits of _Urine_, _Hart-horn_, _Bloud_, &c. witness also
+the curious branches of evaporated dissolutions, some of them against the
+sides of the containing Jar: others standing up, or growing an end, out of
+the bottom, of which I have taken notice of a very great variety. But above
+all the rest, it is a very pretty kind of Germination which is afforded us
+in the Silver Tree, the manner of making which with Mercury and Silver, is
+well known to the Chymists, in which there is an Ebullition or Germination,
+very much like this of Mushroms, if I have been rightly inform'd of it.
+
+Fourthly, I have very often taken notice of, and also observ'd with a
+_Microscope_, certain excrescencies or Ebullitions in the snuff of a
+Candle, which, partly from the sticking of the smoaky particles as they are
+carryed upwards by the current of the rarify'd Air and flame, and partly
+also from a kind of Germination or Ebullition of some actuated unctuous
+parts which creep along and filter through some small string of the Week,
+are formed into pretty round and uniform heads, very much resembling the
+form of hooded Mushroms, which, being by any means expos'd to the fresh
+Air, or that air which encompasses the flame, they are presently lick'd up
+and devour'd by it, and vanish.
+
+The reason of which _Phænomenon_ seems to me, to be no other then this:
+
+That when a convenient thread of the Week is so bent out by the sides of
+the snuff that are about half an Inch or more, remov'd above the bottom, or
+lowest part of the flame, and that this part be wholly included in the
+flame; the Oyl (for the reason of filtration, which I have elsewhere
+rendred) being continualy driven up the snuff is driven likewise into this
+ragged bended-end, and this being remov'd a good distance, as half an Inch
+or more, above the bottom of the flame, the parts of the air that passes by
+it, are already, almost satiated with the dissolution of the boiling
+unctuous steams that issued out below, and therefore are not onely glutted,
+that is, can dissolve no more then what they are already acting upon, but
+they carry up with them abundance of unctuous and sooty particles, which
+meeting with that rag of the Week, that is plentifully fill'd with Oyl, and
+onely spends it as fast as it evaporates, and not at all by dissolution or
+burning, by means of these steamy parts of the filterated Oyl issuing out
+at the sides of this ragg, and being inclos'd with an air that is already
+satiated and cannot prey upon them nor burn them, the ascending sooty
+particles are stay'd about it and fix'd, so as that about the end of that
+ragg or filament of the snuff, whence the greatest part of the steams
+issue, there is conglobated or fix'd a round and pretty uniform cap, much
+resembling the head of a Mushrom, which, if it be of any great bigness, you
+may observe that its underside will be bigger then that which is above the
+ragg or stem of it; for the Oyl that is brought into it by filtration,
+being by the bulk of the cap a little shelter'd from the heat of the flame,
+does by that means issue as much out beneath from the stalk or downwards,
+as it does upwards, and by reason of the great access of the adventitious
+smoak from beneath, it increases most that way. That this may be the true
+reason of this _Phænomenon_, I could produce many Arguments and Experiments
+to make it probable: As,
+
+First, that the _Filtration_ carries the Oyl to the top of the Week, at
+least as high as these raggs, is visible to one that will observe the snuff
+of a burning Candle with a _Microscope_, where he may see an Ebullition or
+bubbling of the Oyl, as high as the snuff looks black.
+
+Next, that it does steam away more then burn; I could tell you of the dim
+burning of a Candle, the longer the snuff be which arises from the
+abundance of vapours out of the higher parts of it.
+
+And, thirdly, that in the middle of the flame of the Candle, neer the top
+of the snuff, the fire or dissolving principle is nothing neer so strong,
+as neer the bottom and out edges of the flame, which may be observ'd by the
+burning asunder of a thread, that will first break in those parts that the
+edges of the flame touch, and not in the middle.
+
+And I could add several Observables that I have taken notice of in the
+flame of a Lamp actuated with Bellows, and very many others that confirm me
+in my opinion, but that it is not so much to my present purpose, which is
+onely to consider this concreet in the snuff of a Candle, so farr as it has
+any resemblance of a Mushrom, to the consideration of which, that I may
+return, I say, we may also observe:
+
+In the fifth place, that the droppings or trillings of Lapidescent waters
+in Vaults under ground, seem to constitute a kind of _petrify'd_ body,
+form'd almost like some kind of Mushroms inverted, in so much that I have
+seen some knobb'd a little at the lower end, though for the most part,
+indeed they are otherwise shap'd, and taper'd towards the end; the
+generation of which seems to be from no other reason but this, that the
+water by soaking through the earth and Lime (for I ghess that substance to
+add much to it _petrifying_ quality) does so impregnate it self with stony
+particles, that hanging in drops in the roof of the Vault, by reason that
+the soaking of the water is but slow, it becomes expos'd to the Air, and
+thereby the outward part of the drop by degrees grows hard, by reason that
+the water gradually evaporating the stony particles neer the outsides of
+the drop begin to touch, and by degrees, to dry and grow closer together,
+and at length constitute a crust or shell about the drop; and this soaking
+by degrees, being more and more supply'd, the drop grows longer and longer,
+and the sides harden thicker and thicker into a Quill or Cane, and at
+length, that hollow or pith becomes almost stop'd up, and solid: afterwards
+the soaking of the _petrifying_ water, finding no longer a passage through
+the middle, bursts out, and trickles down the outside, and as the water
+evaporates, leaves new superinduc'd shells, which more and more swell the
+bulk of those Iceicles, and because of the great supply from the Vault, of
+_petrifying_ wafer, those bodies grow bigger and bigger next to the Vault,
+and taper or sharpen towards the point; for the access from the arch of the
+Vault being but very slow, and consequently the water being spread very
+thinly over the surface of the Iceicle, the water begins to settle before
+it can reach to the bottom, or corner end of it; whence, if you break one
+of these, you would almost imagine it a stick of Wood _petrify'd_, it
+having so pretty a resemblance of pith and grain, and if you look on the
+outside of a piece, or of one whole, you would think no less, both from its
+vegetable roundness and tapering form; but whereas all Vegetables are
+observ'd to shoot and grow perpendicularly upwards, this does shoot or
+propend directly downwards.
+
+By which last Observables, we see that there may be a very pretty body
+shap'd and concreeted by Mechanical principles, without the least shew or
+probability of any other seminal _formatrix_.
+
+And since we find that the great reason of the _Phænomena_ of this pretty
+_petrifaction_, are to be reduc'd from the gravity of a fluid and pretty
+volatil body impregnated with stony particles, why may not the _Phænomena_
+of Ebullition or Germination be in part possibly enough deduc'd from the
+levity of an impregnated liquor, which therefore perpendicularly ascending
+by degrees, evaporates and leaves the more solid and fix'd parts behind in
+the form of a Mushrom, which is yet further diversify'd and specificated by
+the forms of the parts that impregnated the liquor, and compose or help to
+constitute the Mushrom.
+
+That the foremention'd Figures of growing Salts, and the Silver Tree, are
+from this principle, I could very easily manifest, but that I have not now
+a convenient opportunity of following it, nor have I made a sufficient
+number of Experiments and Observations to propound, explicate, and prove so
+usefull a _Theory_ as this of Mushroms: for, though the contrary principle
+to that of _petrify'd_ Iceicles may be in part a cause, yet I cannot but
+think, that there is somewhat a more complicated caufe, though yet
+Mechanical, and possible to be explain'd.
+
+We therefore have further to enquire of it, what makes it to be such a
+liquor, and to ascend, whether the heat of the Sun and Air, or whether that
+_firmentiation_ and _putrifaction_, or both together; as also whether there
+be not a third or fourth; whether a Saline principle be not a considerable
+agent in this business also as well as heat; whether also a fixation,
+precipitation or settling of certain parts out of the aerial menstruum may
+not be also a considerable coadjutor in the business. Since we find that
+many pretty beards _stiriæ_ of the particles of Silver may be precipitated
+upon a piece of Brass put into a _solution_ of Silver very much diluted
+with fair water, which look not unlike a kind of mould or hoar upon that
+piece of metal; and the hoar frost looks like a kind of mould; and whether
+there may not be several others that do concurr to the production of a
+Mushrom, having not yet had sufficient time to prosecute according to my
+desires, I must referr this to a better opportunity of my own, or leave and
+recommend it to the more diligent enquiry and examination of such as can be
+masters both of leisure and conveniencies for such an Enquiry.
+
+And in the mean time, I must conclude, that as far as I have been able to
+look into the nature of this Primary kind of life and vegetation, I cannot
+find the least probable argument to perswade me there is any other
+concurrent cause then such as is purely Mechanical, and that the effects or
+productions are as necessary upon the concurrence of those causes as that a
+Ship, when the Sails are hoist up, and the Rudder is set to such a
+position, should, when the Wind blows, be mov'd in such a way or course to
+that or t'other place; Or, as that the brused Watch, which I mention in the
+description of Moss, should, when those parts which hindred its motion were
+fallen away, begin to move, but after quite another manner then it did
+before.
+
+       *       *       *       *       *
+
+
+Observ. XXI. _Of _Moss_, and several other small-vegetative Substances._
+
+Moss is a Plant, that the wisest of Kings thought neither unworthy his
+speculation, nor his Pen, and though amongst Plants it be in bulk one of
+the smallest, yet it is not the least considerable: For, as to its shape,
+it may compare for the beauty of it with any Plant that grows, and bears a
+much bigger breadth; it has a root almost like a seedy Parsnep, furnish'd
+with small strings and suckers, which are all of them finely branch'd, like
+those of the roots of much bigger Vegetables; out of this springs the stem
+or body of the Plant, which is somewhat _Quadrangular_, rather then
+_Cylindrical_, most curiously _fluted_ or lining with small creases, which
+run, for the most part, _parallel_ the whole stem; on the sides of this are
+close and thick set, a multitude of fair, large, well-shap'd leaves, some
+of them of a rounder, others of a longer shape, according as they are
+younger or older when pluck'd; as I ghess by this, that those Plants that
+had the stalks growing from the top of them, had their leaves of a much
+longer shape, all the surface of each side of which, is curiously cover'd
+with a multitude of little oblong transparent bodies, in the manner as you
+see it express'd in the leaf B, in the XIII. _Scheme_.
+
+This Plant, when young and springing up, does much resemble a Housleek,
+having thick leaves, almost like that, and seems to be somwhat of kin to it
+in other particulars; also from the top of the leaves, there shoots out a
+small white and transparent hair, or thorn: This stem, in time, come to
+shoot out into a long, round and even stalk, which by cutting transversly,
+when dry, I manifestly found to be a stiff, hard, and hollow Cane, or Reed,
+without any kind of knot, or stop, from its bottom, where the leaves
+encompass'd it, to the top, on which there grows a large seed case, A,
+cover'd with a thin, and more whitish skin, B, terminated in a long thorny
+top, which at first covers all the Case, and by degrees, as that swells,
+the skin cleaves, and at length falls off, with its thorny top and all
+(which is a part of it) and leaves the seed Case to ripen, and by degrees,
+to shatter out its seed at a place underneath this cap, B, which before the
+seed is ripe, appears like a flat barr'd button, without any hole in the
+middle; but as it ripens, the button grows bigger, and a hole appears in
+the middle of it, E, out of which, in all probability, the seed falls: For
+as it ripens by a provision of Nature, that end of this Case turns downward
+after the same manner as the ears of Wheat and Barley usually do; and
+opening several of these dry red Cases, F, I found them to be quite hollow,
+without anything at all in them; whereas when I cut them asunder with a
+sharp Pen-knife when green, I found in the middle of this great Case,
+another smaller round Case, between which two, the _interstices_ were
+fill'd with multitudes of stringie _fibres_, which seem'd to suspend the
+lesser Case in the middle of the other, which (as farr as I was able to
+discern) seem'd full of exceeding small white seeds, much like the
+seed-bagg in the knop of a Carnation, after the flowers have been two or
+three days, or a week, fallen off; but this I could not so perfectly
+discern, and therefore cannot positively affirm it.
+
+After the seed was fallen away, I found both the Case, Stalk, and Plant,
+all grow red and wither, and from other parts of the root continually to
+spring new branches or slips, which by degrees increased, and grew as bigg
+as the former, seeded, ripen'd, shatter'd, and wither'd.
+
+I could not find that it observ'd any particular seasons for these several
+kinds of growth, but rather found it to be springing, mature, ripe, seedy,
+and wither'd at all times of the year; But I found it most to flourish and
+increase in warm and moist weather.
+
+It gathers its nourishments, for the most part, out of some _Lapidescent_,
+or other substance corrupted or chang'd from its former texture, or
+substantial form; for I have found it to grow on the rotten parts of Stone,
+of Bricks, of Wood, of Bones, of Leather, &c.
+
+It oft grows on the barks of several Trees, spreading it self, sometimes
+from the ground upwards, and sometimes from some chink or cleft of the bark
+of the Tree, which has some _putrify'd_ substance in it, but this seems of
+a distinct kind from that which I observ'd to grow on _putrify'd_ inanimate
+bodies, and rotten earth.
+
+There are also great varieties of other kinds of Mosses, which grow on
+Trees, and several other Plants, of which I shall here make no mention, nor
+of the Moss growing on the skull of a dead man, which much resembles that
+of Trees.
+
+Whether this Plant does sometimes originally spring or rise out of
+corruption, without any disseminated seed, I have not yet made trials
+enough to be very much, either positive or negative; for as it seems very
+hard to conceive how the seed should be generally dispers'd into all parts
+where there is a corruption begun, unless we may rationally suppose, that
+this seed being so exceeding small, and consequently exceeding light, is
+thereby taken up, and carried to and fro in the Air into every place, and
+by the falling drops of rain is wash'd down out of it, and so dispers'd
+into all places, and there onely takes root and propagates, where it finds
+a convenient soil or matrix for it to thrive in; so if we will have it to
+proceed from corruption, it is not less difficult to conceive,
+
+First, how the corruption of any Vegetable, much less of any Stone or
+Brick, should be the Parent of so curiously figur'd, and so perfect a Plant
+as this is. But here indeed, I cannot but add, that it seems rather to be a
+product of the Rain in those bodies where it is stay'd, then of the very
+bodies themselves, since I have found it growing on Marble, and Flint, but
+always the _Microscope_, if not the naked eye, would discover some little
+hole of Dirt in which it was rooted.
+
+Next, how the corruption of each of those exceedingly differing bodies
+should all conspire to the production of the same Plant, that is, that
+Stones, Bricks, Wood, or vegetable substances, and Bones, Leather, Horns,
+or animate substances, unless we may with some plausibleness say, that Air
+and Water are the coadjutors, or _menstruums_, all kinds of
+_putrifactions_, and that thereby the bodies (though whil'st they retain'd
+their substantial forms, were of exceeding differing natures, yet) since
+they are dissolv'd and mixt into another, they may be very _Homogeneous_,
+they being almost resolv'd again into Air, Water, and Earth; retaining,
+perhaps, one part of their vegetative faculty yet entire, which meeting
+with congruous assistants, such as the heat of the Air, and the fluidity of
+the Water, and such like coadjutors and conveniences, acquires a certain
+vegetation for a time, wholly differing perhaps from that kind of
+vegetation it had before.
+
+To explain my meaning a little better by a gross Similitude:
+
+Suppose a curious piece of Clock-work, that had had several motions and
+contrivances in it, which, when in order, would all have mov'd in their
+design'd methods and Periods. We will further suppose, by some means, that
+this Clock comes to be broken, brused, or otherwise disordered, so that
+several parts of it being dislocated, are impeded, and so stand still, and
+not onely hinder its own progressive motion, and produce not the effect
+which they were design'd for, but because the other parts also have a
+dependence upon them, put a stop to their motion likewise; and so the whole
+Instrument becomes unserviceable,, and not fit for any use. This Instrument
+afterwards, by some shaking and tumbling, and throwing up and down, comes
+to have several of its parts shaken out, and several of its curious
+motions, and contrivances, and particles all fallen asunder; here a Pin
+falls out, and there a Pillar, and here a Wheel, and there a Hammer, and a
+Spring, and the like, and among the rest, away falls those parts also which
+were brused and disorder'd, and had all this while impeded the motion of
+all the rest; hereupon several of those other motions that yet remain,
+whole springs were not quite run down, being now at liberty, begin each of
+them to move, thus or thus, but quite after another method then before,
+there being many regulating parts and the like, fallen away and lost. Upon
+this, the Owner, who chances to hear and observe some of these effects,
+being ignorant of the Watch-makers Art, wonders what is betid his Clock,
+and presently imagines that some Artist has been at work, and has set his
+Clock in order, and made a new kind of Instrument of it, but upon examining
+circumstances, he finds there was no such matter, but that the casual
+slipping out of a Pin had made several parts of his Clock fall to pieces,
+and that thereby the obstacle that all this while hindred his Clock,
+together with other usefull parts were fallen out, and so his Clock was set
+at liberty. And upon winding up those springs again when run down, he finds
+his Clock to go, but quite after another manner then it was wont
+heretofore.
+
+And thus may it be perhaps in the business of Moss, and Mould, and
+Mushroms, and several other spontaneous kinds of vegetations, which may be
+caus'd by a vegetative principle, which was a coadjutor to the life and
+growth of the greater Vegetable, and was by the destroying of the life of
+it stopt and impeded in performing its office; but afterwards, upon a
+further corruption of several parts that had all the while impeded it, the
+heat of the Sun winding up, as it were, the spring, sets it again into a
+vegetative motion, and this being single, and not at all regulated as it
+was before (when a part of that greater _machine_ the pristine vegetable)
+is mov'd after quite a differing manner, and produces effects very
+differing from those it did before.
+
+But this I propound onely as a conjecture, not that I am more enclin'd to
+this _Hypothesis_ then the seminal, which upon good reason I ghess to be
+Mechanical also, as I may elsewhere more fully shew: But because I may, by
+this, hint a possible way how this appearance may be solv'd; supposing we
+should be driven to confess from certain Experiments and Observations made,
+that such or such Vegetables were produc'd out of the corruption of
+another, without any concurrent seminal principle (as I have given some
+reason to suppose, in the description of a _Microscopical_ Mushrome)
+without derogating at all from the infinite wisdom of the Creator. For this
+accidental production, as I may call it, does manifest as much, if not very
+much more, of the excellency of his contrivance as any thing in the more
+perfect vegetative bodies of the world, even as the accidental motion of
+the _Automaton_ does make the owner see, that there was much more
+contrivance in it then at first he imagin'd. But of this I have added more
+in the description of Mould, and the Vegetables on Rose leaves, &c. those
+being much more likely to have their original from such a cause then this
+which I have here described, in the 13. _Scheme_, which indeed I cannot
+conceive otherwise of, then as of a most perfect Vegetable, wanting nothing
+of the perfections of the most conspicuous and vastest Vegetables of the
+world, and to be of a rank so high, as that it may very properly be
+reckon'd with the tall Cedar of _Lebanon_, as that Kingly Botanist has
+done.
+
+We know there may be as much curiosity of contrivance, and excellency of
+form in a very small Pocket-clock, that takes not up an Inch square of
+room, as there may be in a Church-clock that fills a whole room; And I know
+not whether all the contrivances and _Mechanisms_ requisite to a perfect
+Vegetable, may not be crowded into an exceedingly less room then this of
+Moss, as I have heard of a striking Watch so small, that it serv'd for a
+Pendant in a Ladies ear; and I have already given you the description of a
+Plant growing on Rose leaves, that is abundantly smaller then Moss;
+insomuch, that neer 1000. of them would hardly make the bigness of one
+single Plant of Moss. And by comparing the bulk of Moss, with the bulk of
+the biggest kind of Vegetable we meet with in Story (of which kind we find
+in some hotter climates, as _Guine_, and _Brasile_, the stock or body of
+some Trees to be twenty foot in Diameter, whereas the body or stem of Moss,
+for the most part, is not above one sixtieth part of an Inch) we shall find
+that the bulk of the one will exceed the bulk of the other, no less then
+2985984 Millions, or 2985984000000, and supposing the production on a Rose
+leaf to be a Plant, we shall have of those _Indian_ Plants to exceed a
+production of the same Vegetable kingdom no less then 1000 times the former
+number; so prodigiously various are the works of the Creator, and so
+All-sufficient is he to perform what to man would seem unpossible, they
+being both alike easie to him, even as one day, and a thousand years are to
+him as one and the same time.
+
+I have taken notice of such an infinite variety of those smaller kinds of
+vegetations, that should I have described every one of them, they would
+almost have fill'd a Volume, and prov'd bigg enough to have made a new
+Herbal, such multitudes are there to be found in moist hot weather,
+especially in the Summer time, on all kind of putrifying substances, which,
+whether they do more properly belong to the _Classis_ of _Mushrooms_, or
+_Moulds_, or _Mosses_, I shall not now dispute, there being some that seem
+more properly of one kind, others of another, their colours and magnitudes
+being as much differing as their Figures and substances.
+
+Nay, I have observ'd, that putting fair Water (whether Rain-water or
+Pump-water, or _May-dew_ or Snow-water, it was almost all one) I have often
+observ'd, I say, that this Water would, with a little standing, tarnish and
+cover all about the sides of the Glass that lay under water, with a lovely
+green; but though I have often endeavour'd to discover with my _Microscope_
+whether this green were like Moss, or long striped Sea-weed, or any other
+peculiar form, yet so ill and imperfect are our _Microscopes_, that I could
+not certainly discriminate any.
+
+Growing Trees also, and any kinds of Woods, Stones, Bones, &c. that have
+been long expos'd to the Air and Rain, will be all over cover'd with a
+greenish scurff, which will very much foul and green any kind of cloaths
+that are rubb'd against it; viewing this, I could not certainly perceive in
+many parts of it any determinate form, though in many I could perceive a
+Bed as 'twere of young Moss, but in other parts it look'd almost like green
+bushes, and very confus'd, but always of what ever irregular Figures the
+parts appear'd of, they were always green, and seem'd to be either some
+Vegetable, or to have some vegetating principle.
+
+       *       *       *       *       *
+
+
+Observ. XXII. _Of common _Sponges_, and several other _Spongie_ fibrous
+bodies._
+
+A Sponge is commonly reckon'd among the _Zoophyts_, or Plant Animals; and
+the _texture_ of it, which the _Microscope_ discovers, seems to confirm it;
+for it is of a form whereof I never observ'd any other Vegetable, and
+indeed, it seems impossible that any should be of it, for it consists of an
+infinite number of small short _fibres_, or nervous parts, much of the same
+bigness, curiously jointed or contex'd together in the form of a Net, as is
+more plainly manifest by the little Draught which I have added, in the
+third _Figure_ of the IX. _Scheme_, of a piece of it, which you may
+perceive represents a confus'd heap of the fibrous parts curiously jointed
+and implicated. The joints are, for the most part, where three _fibres_
+onely meet, for I have very seldom met with any that had four.
+
+At these joints there is no one of the three that seems to be the stock
+whereon the other grow, but each of the _fibres_ are, for the most part, of
+an equal bigness, and seem each of them to have an equal share in the
+joint; the _fibres_ are all of them much about the same bigness, not
+smaller towards the top of the Sponge, and bigger neerer the bottom or
+root, as is usuall in Plants, the length of each between the joints, is
+very irregular and different; the distance between some two joints, being
+ten or twelve times more then between some others.
+
+Nor are the joints regular, and of an _equitriagonal Figure_, but, for the
+most part, the three _fibres_ so meet, that they compose three angles very
+differing all of them from one another.
+
+The meshes likewise, and holes of this reticulated body, are not less
+various and irregular: some _bilateral_, others _trilateral_, and
+_quadrilateral_ Figures; nay, I have observ'd some meshes to have 5, 6, 7,
+8, or 9. sides, and some to have onely one, so exceeding various is the
+_Lusus Naturæ_ in this body.
+
+As to the outward appearance of this Vegetative body, they are so usuall
+everywhere, that I need not describe them, consisting of a soft and porous
+substance, representing a Lock, sometimes a fleece of Wooll; but it has
+besides these small _microscopical_ pores which lie between the _fibres_, a
+multitude of round pores or holes, which, from the top of it, pierce into
+the body, and sometimes go quite through to the bottom.
+
+I have observ'd many of these Sponges, to have included likewise in the
+midst of their fibrous contextures, pretty large friable stones, which must
+either have been inclos'd whil'st this Vegetable was in formation, or
+generated in those places after it was perfectly shap'd. The later of which
+seems the more improbable, because I did not find that any of these stony
+substances were perforated with the _fibres_ of the Sponge.
+
+I have never seen nor been enform'd of the true manner of the growing of
+Sponges on the Rock; whether they are found to increase from little to
+great, like Vegetables, that is, part after part, or like Animals, all
+parts equally growing together; or whether they be _matrices_ or feed-baggs
+of any kind of Fishes, or some kind of watry Insect; or whether they are at
+any times more soft and tender, or of another nature and texture, which
+things, if I knew how, I should much desire to be informed of: but from a
+cursory view that I at first made with my _Microscope_, and some other
+trials, I supposed it to be some Animal substance cast out, and fastned
+upon the Rocks in the form of a froth, or _congeries_ of bubbles, like that
+which I have often observ'd on Rosemary, and other Plants (wherein is
+included a little Insect) that all the little films which divide these
+bubbles one from another, did presently, almost after the substance began
+to grow a little harder, break, and leave onely the thread behind, which
+might be, as 'twere, the angle or thread between the bubbles, that the
+great holes or pores observable in these Sponges were made by the eruption
+of the included _Heterogeneous_ substance (whether air, or some other body,
+for many other fluid bodies will do the same thing) which breaking out of
+the lesser, were collected into very large bubbles, and so might make their
+way out of the Sponge, and in their passage might leave a round cavity; and
+if it were large, might carry up with it the adjacent bubbles, which may be
+perceiv'd at the outside of the Sponge, if it be first throughly wetted,
+and sufferr'd to plump itself into its natural form, or be then wrung dry,
+and suffer'd to expand it self again, which it will freely do whil'st
+moist: for when it has thus plump'd it self into its natural shape and
+dimensions, 'tis obvious enough that the mouths of the larger holes have a
+kind of lip or rising round about them, but the other smaller pores have
+little or none. It may further be found, that each of these great pores has
+many other small pores below, that are united unto it, and help to
+constitute it, almost like so many rivulets or small streams that
+contribute to the maintenance of a large River. Nor from this _Hypothesis_
+would it have been difficult to explicate, how those little branches of
+_Coral_, smal _Stones_, _shells_, and the like, come to be included by
+these frothy bodies: But this inded was but a conjecture; and upon a more
+accurate enquiry into the form of it with the _Microscope_, it seems not to
+be the true origine of them; for whereas Sponges have onely three arms
+which join together at each knot, if they had been generated from bubbles
+they must have had four.
+
+But that they are Animal Substances, the _Chymical_ examination of them
+seems to manifest, they affording a volatil Salt and spirit, like
+_Harts-Horn_, as does also their great strength and toughness, and their
+smell when burn'd in the Fire or a Candle, which has a kind of fleshy sent,
+not much unlike to hair. And having since examin'd several Authors
+concerning them, among others; I find this account given by _Bellonius_, in
+the XI. _Chap._ of his 2d Book, _De Aquatilibus_. _Spongiæ recentes_, says
+he, _à siccis longe diversæ, scopulis aquæ marinæ ad duos vel tres cubitos,
+nonnunquam quatuor tantum digitos immersis, ut fungi arboribus adhærent,
+sordido quodam succo aut mucosa potius sanie refertæ, usque adeò foetida,
+ut vel eminus nauseam excitet, continetur autem iis cavernis, quas inanes
+in siccis & lotis Spongiis cernimus: Putris pulmonis modo nigræ
+conspiciuntur, verùm quæ in sublimi aquæ nascuntur multo magis opaca
+nigredine suffusæ sunt. Vivere quidem Spongias adhærendo _Aristoteles_
+censet: absolute vero minime: sensumque aliquem habere, vel eo argumento
+(inquit) credantur, quod difficillime abstrahantur, nisi clanculum agatur:
+Atq; ad avulsoris accessum ita contrahantur, ut eas evellere difficile sit,
+quod idem etiam faciunt quoties flatus tempestatésque urgent. Puto autem
+illis succum sordidum quem supra diximus carnis loco à natura attributum
+fuisse: atque meatibus latioribus tanquam intestinis aut interaneis uti.
+Cæterum pars ea quæ Spongiæ cautibus adhærent est tanquam folii petiolus, à
+quo veluti collum quoddam gracile incipit: quod deinde in latitudinem
+diffusum capitis globum facit. Recentibus nihil est fistulosum, hæsitantque
+tanquam radicibus. Superne omnes propemodum meatus concreti latent: inferne
+verò quaterni aut quini patent, per quos eas sugere existimamus_. From
+which Description, they seem to be a kind of Plant-Animal that adheres to a
+Rock, and these small _fibres_ or threads which we have described, seem to
+have been the Vessels which ('tis very probable) were very much bigger
+whil'st the _Interstitia_ were fill'd (as he affirms) with a mucous, pulpy
+or fleshy substance; but upon the drying were shrunk into the bigness they
+now appear.
+
+The texture of it is such, that I have not yet met with any other body in
+the world that has the like, but onely one of a larger sort of Sponge
+(which is preserv'd in the _Museum Harveanum_ belonging to the most
+Illustrious and most learned Society of the _Physicians_ of _London_) which
+is of a horney, or rather of a _petrify'd_ substance. And of this indeed,
+the texture and make is exactly the same with common Sponges, but onely
+that both the holes and the _fibres_, or texture of it is exceedingly much
+bigger, for some of the holes were above an Inch and half over, and the
+_fibres_ and _texture_ of it was bigg enough to be distinguished easily
+with ones eye, but conspicuously with an ordinary single _Microscope_. And
+these indeed, seem'd to have been the habitation of some Animal; and
+examining _Aristotle_, I find a very consonant account hereunto, namely,
+that he had known a certain little Animal, call'd _Pinnothera_, like a
+Spider, to be bred in those caverns of a Sponge, from within which, by
+opening and closing those holes, he insnares and catches the little Fishes;
+and in another place he says, That 'tis very confidently reported, that
+there are certain Moths or Worms that reside in the cavities of a Sponge,
+and are there nourished: Notwithstanding all which Histories, I think it
+well worth the enquiring into the History and nature of a Sponge, it
+seeming to promise some information of the Vessels in Animal substances,
+which (by reason of the solidity of the interserted flesh that is not
+easily remov'd, without destroying also those interspers'd Vessels) are
+hitherto undiscover'd; whereas here in a Sponge, the _Parenchyma_, it
+seems, is but a kind of mucous gelly, which is very easily and cleerly
+wash'd away.
+
+The reason that makes me imagine, that there may probably be some such
+texture in Animal substances, is, that examining the texture of the
+filaments of tann'd Leather, I find it to be much of the same nature and
+strength of a Sponge; and with my _Microscope_, I have observ'd many such
+joints and knobs, as I have described in Sponges, the _fibres_ also in the
+hollow of several sorts of Bones, after the Marrow has been remov'd, I have
+found somewhat to resemble this texture, though, I confess, I never yet
+found any texture exactly the same, nor any for curiosity comparable to it.
+
+The filaments of it are much smaller then those of Silk, and through the
+_Microscope_ appear very neer as transparent, nay, some parts of them I
+have observ'd much more.
+
+Having examin'd also several kinds of Mushroms, I finde their texture to be
+somewhat of this kind, that is, to consist of an infinite company of small
+filaments, every way contex'd and woven together, so as to make a kind of
+cloth, and more particularly, examining a piece of Touch-wood (which is a
+kind _Jews-ear_, or Mushrom, growing here in _England_ also, on several
+sorts of Trees, such as Elders, Maples, Willows, &c. and is commonly call'd
+by the name of _Spunk_; but that we meet with to be sold in Shops, is
+brought from beyond Seas) I found it to be made of an exceeding delicate
+texture: For the substance of it feels, and looks to the naked eye, and may
+be stretch'd any way, exactly like a very fine piece of _Chamois_ Leather,
+or wash'd Leather, but it is of somewhat a browner hew, and nothing neer so
+strong; but examining it with my _Microscope_, I found it of somewhat
+another make then any kind of Leather; for whereas both _Chamois_, and all
+other kinds of Leather I have yet view'd, consist of an infinite company of
+filaments, somewhat like bushes interwoven one within another, that is, of
+bigger parts or stems, as it were, and smaller branchings that grow out of
+them; or like a heap of Ropes ends, where each of the larger Ropes by
+degrees seem to split or untwist, into many smaller Cords, and each of
+those Cords into smaller Lines, and those Lines into Threads, &c. and these
+strangely intangled, or interwoven one within another: The texture of this
+Touch-wood seems more like that of a Lock or a Fleece of Wool, for it
+consists of an infinite number of small filaments, all of them, as farr as
+I could perceive, of the same bigness like those of a Sponge, but that the
+_filaments_ of this were not a twentieth part of the bigness of those of a
+Sponge; and I could not so plainly perceive their joints, or their manner
+of interweaving, though, as farr as I was able to discern with that
+_Microscope_ I had, I suppose it to have some kind of resemblance, but the
+joints are nothing neer so thick, nor without much trouble visible.
+
+The filaments I could plainly enough perceive to be even, round,
+cylindrical, transparent bodies, and to cross each other every way, that
+is, there were not more seem'd to lie _horizontally_ then _perpendicularly_
+and thwartway, so that it is somewhat difficult to conceive how they
+should grow in that manner. By tearing off a small piece of it, and looking
+on the ragged edge, I could among several of those _fibres_ perceive small
+joints, that is, one of those hairs split into two, each of the same
+bigness with the other out of which they seem'd to grow, but having not
+lately had an opportunity of examining their manner of growth, I cannot
+positively affirm any thing of them.
+
+But to proceed, The swelling of Sponges upon wetting, and the rising of the
+Water in it above the surface of the Water that it touches, are both from
+the same cause, of which an account is already given in the sixth
+Observation.
+
+The substance of them indeed, has so many excellent properties, scarce to
+be met with in any other body in the world, that I have often wondered that
+so little use is made of it, and those onely vile and sordid; certainly, if
+it were well consider'd, it would afford much greater conveniencies.
+
+That use which the Divers are said to make of it, seems, if true, very
+strange, but having made trial of it my self, by dipping a small piece of
+it in very good Sallet-oyl, and putting it in my mouth, and then keeping my
+mouth and nose under water, I could not find any such thing; for I was as
+soon out of breath as if I had had no Sponge, nor could I fetch my breath
+without taking in water at my mouth; but I am very apt to think, that were
+there a contrivance whereby the expir'd air might be forc'd to pass through
+a wet or oyly Sponge before it were again inspir'd, it might much cleanse,
+and strain away from the Air divers fuliginous and other noisome steams,
+and the dipping of it in certain liquors might, perhaps, so renew that
+property in the Air which it loses in the Lungs, by being breath'd, that
+one square foot of Air might last a man for respiration much longer,
+perhaps, then ten will now serve him of common Air.
+
+       *       *       *       *       *
+
+
+Observ. XXIII. _Of the curious texture of _Sea-weeds_._
+
+For curiosity and beauty, I have not among all the Plants or Vegetables I
+have yet observ'd, seen any one comparable to this Sea-weed I have here
+describ'd, of which I am able to say very little more then what is
+represented by the second _Figure_ of the ninth _Scheme_: Namely, that it
+is a Plant which grows upon the Rocks under the water, and increases and
+spreads it self into a great tuft, which is not onely handsomely branch'd
+into several leaves, but the whole surface of the Plant is cover'd over
+with a most curious kind of carv'd work, which consists of a texture much
+resembling a Honey-comb; for the whole surface on both sides is cover'd
+over with a multitude of very small holes, being no bigger then so many
+holes made with the point of a small Pinn, and rang'd in the neatest and
+most delicate order imaginable, they being plac'd in the manner of a
+_Quincunx_, or very much like the rows of the eyes of a Fly, the rows or
+orders being very regular, which way soever they are observ'd: what the
+texture was, as it appear'd through a pretty bigg Magnifying _Microscope_,
+I have here adjoin'd in the first _Figure_ of the 14. _Scheme._ which round
+Area ABCD represents a part of the surface about one eighth part of an Inch
+in Diameter: Those little holes, which to the eye look'd round, like so
+many little spots, here appear'd very regularly shap'd holes, representing
+almost the shape of the sole of a round toed shoe, the hinder part of
+which, is, as it were, trod on or cover'd by the toe of that next below it;
+these holes seem'd wall'd about with a very thin and transparent substance,
+looking of a pale straw-colour; from the edge of which, against the middle
+of each hole, were sprouted out four small transparent straw-colour'd
+Thorns, which seem'd to protect and cover those cavities, from either side
+two; neer the root of this Plant, were sprouted out several small branches
+of a kind of bastard _Coralline_, curiously branch'd, though small.
+
+And to confirm this, having lately the opportunity of viewing the large
+Plant (if I may so call it) of a Sponge _petrify'd>_, of which I made
+mention in the last Observation, I found, that each of the Branches or
+Figures of it, did, by the range of its pores, exhibit just such a texture,
+the rows of pores crossing one another, much after the manner as the rows
+of eyes do which are describ'd in the 26. _Scheme_: _Coralline_ also, and
+several sorts of white _Coral_, I have with a _Microscope_ observ'd very
+curiously shap'd. And I doubt not, but that he that shall observe these
+several kinds of Plants that grow upon Rocks, which the Sea sometimes
+overflows, and those heaps of others which are vomited out of it upon the
+shore, may find multitudes of little Plants, and other bodies, which like
+this will afford very beautifull objects for the _Microscope_; and this
+_Specimen_ here is adjoin'd onely to excite their curiosities who have
+opportunity of observing to examine and collect what they find worthy their
+notice; for the Sea, among terrestrial bodies, is also a _prolifick_
+mother, and affords as many Instances of _spontaneous_ generations as
+either the Air or Earth.
+
+       *       *       *       *       *
+
+
+Observ. XXIV. _Of the surfaces of _Rosemary_, and other leaves._
+
+This which is delineated within the circle of the second _Figure_ of the
+14. _Scheme_, is a small part of the back or under side of a leaf of
+Rosemary, which I did not therefore make choice of because it had any thing
+peculiar which was not observable with a _Microscope_ in several other
+Plants, but because it exhibits at one view,
+
+First, a smooth and shining surface, namely, AB, which is a part of the
+upper side of the leaf, that by a kind of hem or doubling of the leaf
+appears on this side. There are multitudes of leaves, which surfaces are
+like this smooth, and as it were quilted, which look like a curious quilted
+bagg of green Silk, or like a Bladder, or some such pliable transparent
+substance, full stuffed out with a green juice or liquor; the surface of
+Rue, or Herbgrass, is polish'd, and all over indented, or pitted, like the
+Silk-worm's Egg, which I shall anon describe; the smooth surfaces of other
+Plants are otherwise quilted, Nature in this, as it were, expressing her
+Needle-work, or imbroidery.
+
+Next a downy or bushy surface, such as is all the under side almost,
+appearing through the _Microscope_ much like a thicket of bushes, and with
+this kind of Down or Hair the leaves and stalks of multitudes of Vegetables
+are covered; and there seems to be as great a variety in the shape, bulk,
+and manner of the growing of these secundary Plants, as I may call them
+(they being, as it were, a Plant growing out of a Plant, or somewhat like
+the hairs of Animals) as there is to be found amongst small shrubs that
+compose bushes; but for the most part, they consist of small transparent
+parts, some of which grow in the shape of small Needles or Bodkins, as on
+the Thistle, Cowag-ecod and Nettle; others in the form of Cat's claws, as
+in Cliders, the beards of Barley, the edges of several sorts of Grass and
+Reeds, &c. in other, as Coltsfoot, Rose-campion, Aps, Poplar, Willow, and
+almost all other downy Plants, they grow in the form of bushes very much
+diversify'd in each particular Plant, That which I have before in the 19.
+Observation noted on Rose-leaves, is of a quite differing kind, and seems
+indeed a real Vegetable, distinct from the leaf.
+
+Thirdly, among these small bushes are observable an infinite company of
+small round Balls, exactly Globular, and very much resembling Pearls,
+namely, CCCC, of these there maybe multitudes observ'd in Sage, and several
+other Plants, which I suppose was the reason why _Athanasius Kircher_
+supposed them to be all cover'd with Spiders Eggs, or young Spiders, which
+indeed is nothing else but some kind of gummous exsudation, which is always
+much of the same bigness. At first sight of these, I confess, I imagin'd
+that they might have been some kind of _matrices_, or nourishing
+receptacles for some small Insect, just as I have found Oak-apples, and
+multitudes of such other large excrescencies on the leaves and other parts
+of Trees and shrubs to be for Flyes, and divers other Insects, but
+observing them to be there all the year, and scarce at all to change their
+magnitude, that conjecture seem'd not so probable. But what ever be the use
+of it, it affords a very pleasant object through the _Microscope_, and may,
+perhaps, upon further examination, prove very luciferous.
+
+       *       *       *       *       *
+
+
+Observ. XXV. _Of the stinging points and juice of _Nettles_, and some other
+venomous Plants._
+
+A Nettle is a Plant so well known to every one, as to what the appearance
+of it is to the naked eye, that it needs no description; and there are very
+few that have not felt as well as seen it; and therefore it will be no news
+to tell that a gentle and slight touch of the skin by a Nettle, does
+oftentime, not onely create very sensible and acute pain, much like that of
+a burn or scald, but often also very angry and hard swellings and
+inflamations of the parts, such as will presently rise, and continue swoln
+divers hours. These observations, I say, are common enough; but how the
+pain is so suddenly created, and by what means continued, augmented for a
+time, and afterwards diminish'd, and at length quite exstinguish'd, has
+not, that I know, been explain'd by any.
+
+And here we must have recourse to our _Microscope_, and that will, if
+almost any part of the Plant be looked on, shew us the whole surface of it
+very thick set with turn-Pikes, or sharp Needles, of the shape of those
+represented in the 15. _Scheme_ and first _Figure_ by AB, which are visible
+also to the naked eye; each of which consists of two parts very distinct
+for shape, and differing also in quality from one another. For the part A,
+is shaped very much like a round Bodkin, from B tapering till it end in a
+very sharp point; it is of substance very hard and stiff, exceedingly
+transparent and cleer, and, as I by many trials certainly found, is hollow
+from top to bottom.
+
+This I found by this Experiment, I had a very convenient _Microscope_ with
+a single Glass which drew about half an Inch, this I had fastned into a
+little frame, almost like a pair of Spectacles, which I placed before mine
+eyes, and so holding the leaf of a Nettle at a convenient distance from my
+eye, I did first, with the thrusting of several of these bristles into my
+skin, perceive that presently after I had thrust them in I felt the burning
+pain begin; next I observ'd in divers of them, that upon thrusting my
+finger against their tops, the Bodkin (if I may so call it) did not in the
+least bend, but I could perceive moving up and down within it a certain
+liquor, which upon thrusting the Bodkin against its basis, or bagg B, I
+could perceive to rise towards the top, and upon taking away my hand, I
+could see it again subside, and shrink into the bagg; this I did very
+often, and saw this _Phænomenon_ as plain as I could ever see a parcel of
+water ascend and descend in a pipe of Glass. But the basis underneath these
+Bodkins on which they were fast, were made of a more pliable substance, and
+looked almost like a little bagg of green Leather, or rather resembled the
+shape and surface of a wilde Cucumber, or _cucumeris asinini_, and I could
+plainly perceive them to be certain little baggs, bladders, or receptacles
+full of water, or as I ghess, the liquor of the Plant, which was poisonous,
+and those small Bodkins were but the Syringe-pipes, or Glyster-pipes, which
+first made way into the skin, and then served to convey that poisonous
+juice, upon the pressing of those little baggs, into the interior and
+sensible parts of the skin, which being so discharg'd, does corrode, or, as
+it were, burn that part of the skin it touches; and this pain will
+sometimes last very long, according as the impression is made deeper or
+stronger.
+
+The other parts of the leaf or surface of the Nettle, have very little
+considerable, but what is common to most of these kinds of Plants, as the
+ruggedness or indenting, and hairiness, and other roughnesses of the
+surface or out-side of the Plant, of which I may say more in another place.
+As I shall likewise of certain little pretty cleer Balls or Apples which I
+have observed to stick to the sides of these leaves, both on the upper and
+under side, very much like the small Apples which I have often observ'd to
+grow on the leaves of an Oak call'd _Oak-apples_ which are nothing but the
+_Matrices_ of an Infect, as I elsewhere shew.
+
+The chief thing therefore is, how this Plant comes, by so slight a touch,
+to create so great a pain; and the reason of this seems to be nothing else,
+but the corrosive penetrant liquor contain'd in the small baggs or
+bladders, upon which grow out those sharp Syringe-pipes, as I before noted;
+and very consonant to this, is the reason of the pain created by the sting
+of a Bee, Wasp, &c. as I elsewhere shew: For by the Dart, which is likewise
+a pipe, is made a deep passage into the skin, and then by the anger of the
+Fly, is his gally poisonous liquor injected; which being admitted among the
+sensible parts, and so mix'd with the humours or _stagnating_ juices of
+that part, does create an Ebullition perhaps, or _effervescens_, as is
+usually observ'd in the mingling of two differing _Chymical saline_
+liquors, by which means the parts become swell'd, hard, and very painfull;
+for thereby the nervous and sensible parts are not onely stretch'd and
+strain'd beyond their natural _tone_, but are also prick'd, perhaps, or
+corroded by the pungent and incongruous parts of the intruded liquor.
+
+And this seems to be the reason, why _Aqua fortis_, and other _saline_
+liquors, if they come to touch the sensitive parts, as in a cut of the
+skin, or the like, do so violently and intollerably _excruciate_ and
+torment the Patient. And 'tis not unlikely, but the Inventors of that
+Diabolical practice of poisoning the points of Arrows and Ponyards, might
+receive their first hint from some such Instance in natural contrivances,
+as this of the Nettle: for the ground why such poison'd weapons kill so
+infallibly as they do, seems no other then this of our Nettle's stinging;
+for the Ponyard or Dart makes a passage or entrance into the sensitive or
+vital parts of the body, whereby the contagious substance comes to be
+dissolv'd by, and mix'd with the fluid parts or humours of the body, and by
+that means spreads it self by degrees into the whole liquid part of the
+body, in the same manner, as a few grains of Salt, put into a great
+quantity of Water, will by degrees diffuse it self over the whole.
+
+And this I take to be the reason of killing of Toads, Frogs, Effs, and
+several Fishes, by strewing Salt on their backs (which Experiment was shewn
+to the _Royal Society_ by a very ingenious Gentleman, and a worthy Member
+of it) for those creatures having always a continual exsudation, as it
+were, of slimy and watry parts, sweating out of the pores of their skin,
+the _saline_ particles, by that means obtain a _vehicle_, which conveys
+them into the internal and vital parts of the body.
+
+This seems also to be the reason why bathing in Mineral waters are such
+soveraign remedies for multitudes of distempers, especially chronical; for
+the liquid & warm _vehicles_ of the Mineral particles, which are known to
+be in very considerable quantities in those healing baths, by the body's
+long stay in them, do by degrees steep and insinuate themselves into the
+pores and parts of the skin, and thereby those Mineral particles have their
+ways and passages open'd to penetrate into the inner parts, and mingle
+themselves with the _stagnant_ juices of the several parts; besides, many
+of those offensive parts which were united with those _stagnant_ juices,
+and which were contrary to the natural constitution of the parts, and so
+become irksome and painfull to the body, but could not be discharged,
+because Nature had made no provision for such accidental mischiefs, are, by
+means of this soaking, and filling the pores of the skin with a liquor,
+afforded a passage through that liquor that fills the pores into the
+ambient fluid, and thereby the body comes to be discharged.
+
+So that 'tis very evident, there may be a good as well as an evil
+application of this Principle. And the ingenious Invention of that
+Excellent person, Doctor _Wren_ of injecting liquors into the veins of an
+Animal, seems to be reducible to this head: I cannot stay, nor is this a
+fit place, to mention the several Experiments made of this kind by the most
+incomparable Mr. _Boyle_, the multitudes made by the lately mention'd
+_Physician_ Doctor _Clark_, the History whereof, as he has been pleas'd to
+communicate to the _Royal Society_, so he may perhaps be prevail'd with to
+make publique himself: But I shall rather hint, that certainly, if this
+Principle were well consider'd, there might, besides the further improving
+of Bathing and Syringing into the veins, be thought on several ways,
+whereby several obstinate distempers of a humane body, such as the Gout,
+Dropsie, Stone, &c. might be master'd, and expell'd; and good men might
+make as good a use of it, as evil men have made a perverse and Diabolical.
+
+And that the filling of the pores of the skin with some fluid _vehicle_, is
+of no small efficacy towards the preparing a passage for several kinds of
+penetrant juices, and other dissoluble bodies, to insinuate themselves
+within the skin, and into the sensitive parts of the body, may be, I think,
+prov'd by an Instance given us by _Bellonius_, in the 26. _Chapter_ of the
+second Book of his _Observations_, which containing a very remarkable Story
+I have here transcrib'd: _Cum Chamæleonis nigri radices_ (says he) _apud
+Pagum quendam Livadochorio nuncupatum erui curaremus, plurimi Græci & Turcæ
+spectatum venerunt quid erueremus, eas vero frustulatim secabamus, & filo
+trajiciebamus ut facilius exsiccari possent. Turcæ in eo negotio occupatos
+nos videntes, similiter eas radices tractare & secare voluerunt: at cum
+summus esset æstus, & omnes sudore maderent, quicunque eam radicem manibus
+tractaverant sudoremque absterserant, aut faciem digitis scalpserant,
+tantam pruriginem iis locis quos attigerant postea senserunt, ut aduri
+viderentur. Chamæleonis enim nigri radix ea virtute pollet, ut cuti
+applicata ipsam adeo inflammet, ut nec squillæ, nec urticæ ullæ centesima
+parte ita adurent: At prurigo non adeo celeriter sese prodit. Post unam aut
+alteram porro horam, singuli variis faciei locis cutem adeo inflammatam
+habere cæpimus ut tota sanguinea videretur, atque quo magis eam
+confricabamus, tanto magis excitabatur prurigo. Fonti assidebamus sub
+platano, atque initio pro ludicro habebamus & ridebamus: at tandem illi
+plurimum indignati sunt, & nisi asseverassemus nunquam expertos tali
+virtute eam plantam pollere, haud dubie male nos multassent, Attamen nostra
+excusatio fuit ab illis facilitus accepta, cum eodem incommodo nos affectos
+conspicerent. Mirum sane quod in tantillo radice tam ingentem efficaciam
+nostro malo experti sumus._
+
+By which observation of his, it seems manifest, that their being all
+cover'd with sweat who gather'd and cut this root of the black _Chameleon_
+Thistle, was the great reason why they suffer'd that inconvenience, for it
+seems the like circumstance had not been before that noted, nor do I find
+any mention of such a property belonging to this Vegetable in any of the
+Herbals I have at present by me.
+
+I could give very many Observations which I have made of this kind, whereby
+I have found that the best way to get a body to be insinuated into the
+substance or insensible pores of another, is first, to find a fluid
+_vehicle_ that has some congruity, both to the body to be insinuated, and
+to the body into whose pores you would have the other convey'd. And in this
+Principle lies the great mystery of staining several sorts of bodies, as
+Marble, Woods, Bones, &c. and of Dying Silks, Cloaths, Wools, Feathers, &c.
+But these being digressions, I shall proceed to:
+
+       *       *       *       *       *
+
+
+Observ. XXVI. _Of _Cowage_, and the itching operation of some bodies._
+
+There is a certain Down of a Plant, brought from the _East-Indies_, call'd
+commonly, though very improperly, _Cow-itch_, the reason of which mistake
+is manifest enough from the description of it, which Mr. _Parkinson_ sets
+down in his _Herbal_, Tribe XI. Chap. 2. _Phasiolus siliqua hirsuta; The
+hairy Kidney-bean, called in _Zurratte_ where it grows, Couhage: We have
+had_ (says he) _another of this kind brought us out of the _East-Indies_,
+which being planted was in shew like the former, but came not to
+perfection, the unkindly season not suffering it to shew the flower; but of
+the Cods that were brought, some were smaller, shorter, and rounder then
+the Garden kind; others much longer, and many growing together, as it were
+in clusters, and cover'd all over with a brown short hairiness, so fine,
+that if any of it be rubb'd, or fall on the back of ones hand, or other
+tender parts of the skin, it will cause a kind of itching, but not strong,
+nor long induring, but passing quickly away, without either danger or harm;
+the Beans were smaller then ordinary, and of a black shining colour._
+
+Having one of these Cods given me by a Sea-Captain, who had frequented
+those parts, I found it to be a small Cod, about three Inches long, much
+like a short Cod of _French Beans_, which had six Beans in it, the whole
+surface of it was cover'd over with a very thick and shining brown Down or
+Hair, which was very fine, and for its bigness stiff; taking some of this
+Down, and rubbing it on the back of my hand, I found very little or no
+trouble, only I was sensible that several of these little downy parts with
+rubbing did penetrate, and were sunk, or stuck pretty deep into my skin.
+After I had thus rubb'd it for a pretty while, I felt very little or no
+pain, in so much that I doubted, whether it were the true Couhage; but
+whil'st I was considering; I found the Down begin to make my hand itch, and
+in some places to smart again, much like the stinging of a Flea or Gnat,
+and this continued a pretty while, so that by degrees I found my skin to be
+swell'd with little red pustules, and to look as if it had been itchie. But
+suffering it without rubbing or scratching, the itching tickling pain
+quickly grew languid, and within an hour I felt nothing at all, and the
+little _protuberancies_ were vanish'd.
+
+The cause of which odd _Phænomenon_, I suppose to be much the same with
+that of the stinging of a Nettle, for by the _Microscope_, I discover'd
+this Down to consist of a multitude of small and slender conical bodies,
+much resembling Needles or Bodkins, such as are represented by AB. CD. EF.
+of the first Figure of the XVI. _Scheme_; that their ends AAA, were very
+sharp, and the substance of them stiff and hard, much like the substance of
+several kinds of Thorns and crooks growing on Trees. And though they
+appear'd very cleer and transparent, yet I could not perceive whether they
+were hollow or not, but to me they appear'd like solid transparent bodies,
+without any cavity in them; whether, though they might not be a kind of
+Cane, fill'd with some transparent liquor which was hardned (because the
+Cod which I had was very dry) I was not able to examine.
+
+Now, being such stiff, sharp bodies, it is easie to conceive, how with
+rubbing they might easily be thrust into the tender parts of the skin, and
+there, by reason of their exceeding fineness and driness, not create any
+considerable trouble or pain, till by remaining in those places moistned
+with the humours of the body, some caustick part sticking on them, or
+residing within them might be dissolv'd and mix'd with the ambient juices
+of that place, and thereby those _fibres_ and tender parts adjoyning become
+affected, and as it were corroded by it; whence, while that action lasts,
+the pains created are pretty sharp and pungent, though small, which is the
+essential property of an itching one.
+
+That the pain also caused by the stinging of a Flea, a Gnat, a Flie, a
+Wasp, and the like, proceeds much from the very same cause, I elsewhere in
+their proper places endeavour to manifest. The stinging also of shred
+Hors-hair, which in meriment is often strew'd between the sheets of a Bed,
+seems to proceed from the same cause.
+
+       *       *       *       *       *
+
+
+Observ. XXVII. _Of the _Beard_ of a wilde _Oat_, and the use that may be
+made of it for exhibiting always to the Eye the temperature of the Air, as
+to driness and moisture._
+
+This Beard of a wild _Oat_, is a body of a very curious structure, though
+to the naked Eye it appears very slight, and inconsiderable, it being only
+a small black or brown Beard or Bristle, which grows out of the side of the
+inner Husk that covers the Grain of a wild _Oat_; the whole length of it,
+when put in Water, so that it may extend it self to its full length, is not
+above an Inch and a half, and for the most part somewhat shorter, but when
+the Grain is ripe, and very dry, which is usualy in the Moneths of _July_,
+and _August_, this Beard is bent somewhat below the middle, namely, about
+2/5 from the bottom of it, almost to a right Angle, and the under part of
+it is wreath'd lik a With; the substance of it is very brittle when dry,
+and it will very easily be broken from the husk on which it grows.
+
+If you take one of these Grains, and wet the Beard in Water, you will
+presently see the small bended top to turn and move round, as if it were
+sensible; and by degrees, if it be continued wet enough, the joint or knee
+will streighten it self; and if it be suffer'd to dry again, it will by
+degrees move round another way, and at length bend again into its former
+posture.
+
+If it be view'd with an ordinary single _Microscope_, it will appear like a
+small wreath'd Sprig, with two clefts; and if wet as before, and then
+look'd on with this _Microscope_, it will appear to unwreath it self, and
+by degrees, to streighten its knee, and the two clefts will become
+streight, and almost on opposite sides of the small cylindrical body.
+
+If it be continued to be look'd on a little longer with a _Microscope_, it
+will within a little while begin to wreath it self again, and soon after
+return to its former posture, bending it self again neer the middle, into a
+kind of knee or angle.
+
+Several of those bodies I examin'd with larger _Microscopes_, and there
+found them much of the make of those two long wreath'd cylinders delineated
+in the second Figure of the 15. _Scheme_, which two cylinders represent the
+wreathed part broken into two pieces, whereof the end AB is to be suppos'd
+to have join'd to the end CD, so that EACF does represent the whole
+wreath'd part of the Beard, and EG a small piece of the upper part of the
+Beard which is beyond the knee, which as I had not room to insert, so was
+it not very considerable, either for its form, or any known property; but
+the under or wreathed part is notable for both: As to its form, it
+appear'd, if it were look'd on side-ways, almost like a Willow, or a small
+tapering rod of _Hazel_, the lower or bigger half of which onely, is
+twisted round several times, in some three, in others more, in others less,
+according to the bigness and maturity of the Grain on which it grew, and
+according to the driness and moisture of the ambient Air, as I shall shew
+more at large by and by.
+
+The whole outward Superficies of this Cylindrical body is curiously adorned
+or fluted with little channels, and interjacent ridges, or little
+_protuberances_ between them, which run the whole length of the Beard, and
+are streight where the Beard is not twisted, and wreath'd where it is, just
+after the same manner: each of those sides is beset pretty thick with small
+Brides or Thorns, somewhat in form resembling that of _Porcupines_ Quills,
+such as _aaaaa_ in the Figure; all whose points are directed like so many
+Turn-pikes towards the small end or top of the Beard, which is the reason,
+why, if you endeavour to draw the Beard between your fingers the contrary
+way, you will find it to stick, and grate, as it were, against the skin.
+
+The proportion of these small conical bodies _aaaaa_ to that whereon they
+grow, the Figure will sufficiently shew, as also their manner of growing,
+their thickness, and neerness to each other, as, that towards the root or
+bottom of the Beard, they are more thin, and much shorter, insomuch that
+there is usually left between the top of the one, and the bottom of that
+next above it, more then the length of one of them, and that towards the
+top of the Beard they grow more thick and close (though there be fewer
+ridges) so that the root, and almost half the upper are hid by the tops of
+those next below them.
+
+I could not perceive any _transverse_ pores, unless the whole wreath'd part
+were separated and cleft, in those little channels, by the wreathing into
+so many little strings as there were ridges, which was very difficult to
+determine; but there were in the wreathed part two very conspicuous
+channels or clefts, which were continued from the bottom F to the elbow bow
+EH or all along the part which was wreath'd, which seem'd to divide the
+wreath'd Cylinder into two parts, a bigger and a less; the bigger was that
+which was at the _convex_ side of the knee, namely, on the side A, and was
+wreath'd by OOOOO; this, as it seem'd the broader, so did it also the
+longer, the other PPPPP, which was usually purs'd or wrinckled in the
+bending of the knee, as about E, seem'd both the shorter and narrower, so
+that at first I thought the wreathing and unwreathing of the Beard might
+have been caus'd by the shrinking or swelling of that part; but upon
+further examination, I found that the clefts, KK, LL, were stuft up with a
+kind of Spongie substance, which, for the most part, was very conspicuous
+neer the knee, as in the cleft KK, when the Beard was dry; upon the
+discovery of which, I began to think, that it was upon the swelling of this
+porous pith upon the access of moisture or water that the Beard, being made
+longer in the midst, was streightned, and by the shrinking or subsiding of
+the parts of that Spongie substance together, when the water or moisture
+was exhal'd or dried, the pith or middle parts growing shorter, the whole
+became twisted.
+
+But this I cannot be positive in, for upon cutting the wreath'd part in
+many places transversly, I was not so well satisfy'd with the shape and
+manner of the pores of the pith; for looking on these transverse Sections
+with a very good _Microscope_, I found that the ends of those transverse
+Sections appear'd much of the manner of the third Figure of the 15.
+_scheme_ ABCFE, and the middle of pith CC, seem'd very full of pores
+indeed, but all of them seem'd to run the long-ways.
+
+This Figure plainly enough shews in what manner those clefts, K and L
+divided the wreath'd Cylinder into two unequal parts, and also of what kind
+of substance the whole body consists; for by cutting the same Beard in many
+places, with transverse Sections, I found much the same appearance with
+this express'd; so that those pores seem to run, as in most other such Cany
+bodies, the whole length of it.
+
+The clefts of this body KK, and LL, seem'd (as is also express'd in the
+Figure) to wind very oddly in the inner part of the wreath, and in some
+parts of them, they seem'd stuffed, as it were, with that Spongie
+substance, which I just now described.
+
+This so oddly constituted Vegetable substance, is first (that I have met
+with) taken notice of by _Baptista Porta_, in his _Natural Magick_, as a
+thing known to children and Juglers, and it has been call'd by some of
+those last named persons, the better to cover their cheat, the Legg of an
+_Arabian Spider_, or the Legg of an inchanted _Egyptian fly_, and has been
+used by them to make a small Index, Cross, or the like, to move round upon
+the wetting of it with a drop of Water, and muttering certain words.
+
+But the use that has been made of it, for the discovery of the various
+constitutions of the Air, as to driness and moistness, is incomparably
+beyond any other, for this it does to admiration: The manner of contriving
+it so, as to perform this great effect, is onely thus:
+
+Provide a good large Box of Ivory, about four Inches over, and of what
+depth you shall judge convenient (according to your intention of making use
+of one, two, three, or more of these small Beards, ordered in the manner
+which I shall by and by describe) let all the sides of this Box be turned
+of Basket-work (which here in _London_ is easily enough procur'd) full of
+holes, in the manner almost of a Lettice, the bigger, or more the holes
+are, the better, that so the Air may have the more free passage to the
+inclosed Beard, and may the more easily pass through the Instrument; it
+will be better yet, though not altogether so handsom, if insteed of the
+Basket-work on the sides of the Box, the bottom and top of the Box be
+join'd together onely with three or four small Pillars, after the manner
+represented in the 4. Figure of the 15. _Scheme_. Or, if you intend to make
+use of many of these small Beards join'd together, you may have a small
+long Case of Ivory, whose sides are turn'd of Basket-work, full of holes,
+which may be screw'd on to the underside of a broad Plate of Ivory, on the
+other side of which is to be made the divided Ring or Circle, to which
+divisions the pointing of the Hand or Index, which is moved by the
+conjoin'd Beard, may shew all the _Minute_ variations of the Air.
+
+There may be multitudes of other ways for contriving this small Instrument,
+so as to produce this effect, which any one may, according to his peculiar
+use, and the exigency of his present occasion, easily enough contrive and
+take, on which I shall not therefore insist. The whole manner of making any
+one of them is thus: Having your Box or frame AABB, fitly adapted for the
+free passage of the Air through it, in the midst of the bottom BBB, you
+must have a very small hole C, into which the lower end of the Beard is to
+be fix'd, the upper end of which Beard ab, is to pass through a small hole
+of a Plate, or top AA, if you make use onely of a single one, and on the
+top of it e, is to be fix'd a small and very light _Index_ fg, made of a
+very thin sliver of a Reed or Cane; but if you make use of two or more
+Beards, they must be fix'd and bound together, either with a very fine
+piece of Silk, or with a very small touch of hard Wax, or Glew, which is
+better, and the _Index_ fg, is to be fix'd on the top of the second, third,
+or fourth in the same manner as on the single one.
+
+Now, because that in every of these contrivances, the _Index_ fg, will with
+some temperatures of Air, move two, three, or more times round, which
+without some other contrivance then this, will be difficult to distinguish,
+therefore I thought of this Expedient: The _Index_ or _Hand_ fg, being
+rais'd a pretty way above the surface of the Plate AA, fix in at a little
+distance from the middle of it a small Pin h, so as almost to touch the
+surface of the Plate AA, and then in any convenient place of the surface of
+the Plate, fix a small Pin, on which put on a small piece of Paper, or thin
+Past-board, Vellom, or Parchment, made of a convenient cize, and shap'd in
+the manner of that in the Figure express'd by ik, so that having a
+convenient number of teeth every turn or return of the Pin h, may move this
+small indented Circle, a tooth forward or backwards, by which means the
+teeth of the Circle, being mark'd, it will be thereby very easie to know
+certainly, how much variation any change of weather will make upon the
+small wreath'd body. In the making of this Secundary Circle of Vellom, or
+the like, great care is to be had, that it be made exceeding light, and to
+move very easily, for otherwise a small variation will spoil the whole
+operation. The Box may be made of Brass, Silver, Iron, or any other
+substance, if care be taken to make it open enough, to let the Air have a
+sufficiently free access to the Beard. The _Index_ also may be various ways
+contrived, so as to shew both the number of the revolutions it makes, and
+the _Minute_ divisions of each revolution.
+
+I have made several trials and Instruments for discovering the driness and
+moisture of the Air with this little wreath'd body, and find it to vary
+exceeding sensibly with the least change in the constitution of the Air, as
+to driness and moisture, so that with one breathing upon it, I have made it
+untwist a whole bout, and the _Index_ or _Hand_ has shew'd or pointed to
+various divisions on the upper Face or Ring of the Instrument, according as
+it was carried neerer and neerer to the fire, or as the heat of the Sun
+increased upon it.
+
+Other trials I have made with Gut-strings, but find them nothing neer so
+sensible, though they also may be so contriv'd as to exhibit the changes of
+the Air, as to driness and moisture, both by their stretching and shrinking
+in length, and also by their wreathing and unwreathing themselves; but
+these are nothing neer so exact or so tender, for their varying property
+will in a little time change very much. But there are several other
+Vegetable substances that are much more sensible then even this Beard of a
+wilde _Oat_; such I have found the Beard of the seed of Musk-grass, or
+_Geranium moschatum_, and those of other kinds of _Cranes-bil_ seeds, and
+the like. But always the smaller the wreathing substance be, the more
+sensible is it of the mutations of the Air, a conjecture at the reason of
+which I shall by and by add.
+
+The lower end of this wreath'd Cylinder being stuck upright in a little
+soft Wax, so that the bended part or _Index_ of it lay _horizontal_, I have
+observ'd it always with moisture to unwreath it self from the East (For
+instance) by the South to the West, and so by the North to the East again,
+moving with the Sun (as we commonly say) and with heat and drouth to
+re-twist; and wreath it self the contrary way, namely, from the East, (for
+instance) by the North to the West, and so onwards.
+
+The cause of all which _Phænomena_, seems to be the differing texture of
+the parts of these bodies, each of them (especially the Beard of a wilde
+_Oat_, and of _Mosk-grass_ seed) seeming to have two kind of substances,
+one that is very porous, loose, and spongie, into which the watry steams of
+the Air may be very easily forced, which will be thereby swell'd and
+extended in its dimensions, just as we may observe all kind of Vegetable
+substance upon steeping in water to swell and grow bigger and longer. And a
+second that is more hard and close, into which the water can very little,
+or not at all penetrate, this therefore retaining always very neer the same
+dimensions, and the other stretching and shrinking, according as there is
+more or less moisture or water in its pores, by reason of the make and
+shape of the parts, the whole body must necessarily unwreath and wreath it
+self.
+
+And upon this Principle, it is very easie to make several sorts of
+contrivances that should thus wreath and unwreath themselves, either by
+heat and cold, or by driness and moisture, or by any greater or less force,
+from whatever cause it proceed, whether from gravity or weight, or from
+wind which is motion of the Air, or from some springing body, or the like.
+
+This, had I time, I should enlarge much more upon; for it seems to me to be
+the very first footstep of _Sensation_, and Animate motion, the most plain,
+simple, and obvious contrivance that Nature has made use of to produce a
+motion; next to that of Rarefaction and Condensation by heat and cold. And
+were this Principle very well examin'd, I am very apt to think, it would
+afford us a very great help to find out the _Mechanism_ of the Muscles,
+which indeed, as farr as I have hitherto been able to examine, seems to me
+not so very perplex as one might imagine, especially upon the examination
+which I made of the Muscles of _Crabs_, _Lobsters_, and several sorts of
+large Shell-fish, and comparing my Observations on them, with the
+circumstances I observ'd in the muscles of terrestrial Animals.
+
+Now, as in this Instance of the Beard of a wilde _Oat_, we see there is
+nothing else requisite to make it wreath and unwreath it self, and to
+streighten and bend its knee, then onely a little breath of moist or dry
+Air, or a small _atome_ almost of water or liquor, and a little heat to
+make it again evaporate, for, by holding this Beard, plac'd and fix'd as I
+before directed, neer a Fire, and dipping the tip of a small shred of Paper
+in well rectify'd spirit of Wine, and then touching the wreath'd
+_Cylindrical_ part, you may perceive it to untwist it self; and presently
+again, upon the _avolation_ of the spirit, by the great heat, it will
+re-twist it self, and thus will it move forward and backwards as oft as you
+repeat the touching it with the spirit of Wine; so may, perhaps, the
+shrinking and relaxing of the muscles be by the influx and evaporation of
+some kind of liquor or juice. But of this Enquiry I shall add more
+elsewhere.
+
+       *       *       *       *       *
+
+
+Observ. XXVIII. _Of the Seeds of _Venus_ looking-glass, or _Corn_ Violet._
+
+From the Leaves, and Downs, and Beards of Plants, we come at last to the
+Seeds; and here indeed seems to be the Cabinet of Nature, wherein are laid
+up its Jewels. The providence of Nature about Vegetables, is in no part
+manifested more, then in the various contrivances about the seed, nor
+indeed is there in any part of the Vegetable so curious carvings, and
+beautifull adornments, as about the seed; this in the larger sorts of seeds
+is most evident to the eye; nor is it lest manifest through the
+_Microscope_, in those seeds whose shape and structure, by reason of their
+smalness, the eye is hardly able to distinguish.
+
+Of these there are multitudes, many of which I have observ'd through a
+_Microscope_, and find, that they do, for the most part, every one afford
+exceeding pleasant and beautifull objects. For besides those that have
+various kinds of carv'd surfaces, there are other that have smooth and
+perfectly polish'd surfaces, others a downy hairy surface; some are cover'd
+onely with a skin, others with a kind of shell, others with both, as is
+observable also in greater seeds.
+
+Of these seeds I have onely described four sorts which may serve as a
+_specimen_ of what the inquisitive observers are likely to find among the
+rest. The first of these seeds which are described in the 17. _Scheme_, are
+those of Corn-Violets, the seed is very small, black, and shining, and, to
+the naked eye, looks almost like a very small Flea; But through the
+_Microscope_, it appears a large body, cover'd with a tough thick and
+bright reflecting skin very irregularly shrunk and pitted, insomuch that
+it is almost an impossibility to find two of them wrinkled alike, so great
+a variety may there be even in this little seed.
+
+This, though it appear'd one of the most promising seeds for beauty to the
+naked eye, yet through the _Microscope_ it appear'd but a rude mishapen
+seed, which I therefore drew, that I might thereby manifest how unable we
+are by the naked eye to judge of beauteous or less curious _microscopical_
+Objects; cutting some of them in sunder, I observ'd them to be fill'd with
+a greenish yellow pulp, and to have a very thick husk, in proportion to the
+pulp.
+
+       *       *       *       *       *
+
+
+Observ. XXIX. _Of the Seeds of _Tyme_._
+
+These pretty fruits here represented, in the 18. _Scheme_, are nothing
+else, but nine several seeds of Tyme; they are all of them in differing
+posture, both as to the eye and the light; nor are they all of them exactly
+of the same shape, there being a great variety both in the bulk and figure
+of each seed; but they all agreed in this, that being look'd on with a
+_Microscope_, they each of them exactly resembled a Lemmon or Orange dry'd;
+and this both in shape and colour. Some of them are a little rounder, of
+the shape of an Orange, as A and B, they have each of them a very
+conspicuous part by which they were join'd to their little stalk, and one
+of them had a little piece of stalk remaining on; the opposite side of the
+seed, you may perceive very plainly by the Figure, is very copped and
+prominent, as is very usual in Lemmons; which prominencies are express'd in
+D, E and F.
+
+They seem'd each of them a little creas'd or wrinckled, but E was very
+conspicuously furrow'd, as if the inward make of this seed had been
+somewhat like that of a Lemmon also, but upon dividing several seeds with a
+very sharp Pen-knife, and examining them afterward, I found their make to
+be in nothing but bulk differing from that of Peas, that is, to have a
+pretty thick coat, and all the rest an indifferent white pulp, which seem'd
+very close; so that it seems Nature does not very much alter her method in
+the manner of inclosing and preserving the vital Principle in the seed, in
+these very small grains, from that of Beans, Peas, &c.
+
+The Grain affords a very pretty Object for the _Microscope_, namely, a Dish
+of Lemmons plac'd in a very little room; should a Lemmon or Nut be
+proportionably magnify'd to what this seed of Tyme is, it would make it
+appear as bigg as a large Hay-reek and it would be no great wonder to see
+_Homers Iliads_, and _Homer_ and all, cramm'd into such a Nutshell. We may
+perceive even in these small Grains, as well as in greater, how curious and
+carefull Nature is in preserving the seminal principle of Vegetable bodies,
+in what delicate, strong and most convenient Cabinets she lays them and
+closes them in a pulp for their safer protection from outward dangers, and
+for the supply of convenient alimental juice, when the heat of the Sun
+begins to animate and move these little _automatons_ or Engines; as if she
+would, from the ornaments wherewith she has deckt these Cabinets, hint to
+us, that in them she has laid up her Jewels and Master-pieces. And this, if
+we are but diligent in observing, we shall find her method throughout.
+There is no curiosity in the Elemental kingdom, if I may so call the bodies
+of Air, Water, Earth, that are comparable in form to those of Minerals, Air
+and Water having no form at all, unless a potentiality to be form'd into
+Globules; and the clods and parcels of Earth are all irregular, whereas in
+Minerals she does begin to _Geometrize_, and practise, as 'twere, the first
+principles of _Mechanicks_, shaping them of plain regular figures, as
+triangles, squares, &c. and _tetraedrons_, cubes, &c. But none of their
+forms are comparable to the more compounded ones of Vegetables; For here
+she goes a step further, forming them both of more complicated shapes, and
+adding also multitudes of curious Mechanick contrivances in their
+structure; for whereas in Vegetables there was no determinate number of the
+leaves or branches, nor no exacly certain figure of leaves, or flowers, or
+seeds, in Animals all those things are exactly defin'd and determin'd; and
+where-ever there is either an excess or defect of those determinate parts
+or limbs, there has been some impediment that has spoil'd the principle
+which was most regular: Here we shall find, not onely most curiously
+compounded shapes, but most stupendious Mechanisms and contrivances, here
+the ornaments are in the highest perfection, nothing in all the Vegetable
+kingdom that is comparable to the deckings of a Peacock; nay, to the
+curiosity of any feather, as I elsewhere shew; nor to that of the smallest
+and most despicable Fly. But I must not stay on these speculations, though
+perhaps it were very well worth while for one that had leisure, to see what
+Information may be learn'd of the nature, or use, or virtues of bodies, by
+their several forms and various excellencies and properties. Who knows but
+_Adam_ might from some such contemplation, give names to all creatures? If
+at least his names had any significancy in them of the creatures nature on
+which he impos'd it; as many (upon what grounds I know not) have suppos'd:
+And who knows, but the Creator may, in those characters, have written and
+engraven many of his most mysterious designs and counsels, and given man a
+capacity, which, assisted with diligence and industry, may be able to read
+and understand them. But not to multiply my digression more then I can the
+time, I will proceed to the next, which is,
+
+       *       *       *       *       *
+
+
+Observ. XXX. _Of the Seeds of _Poppy_._
+
+The small seeds of Poppy, which are described in the 19. _Scheme_, both for
+their smalness, multiplicity and prettiness, as also for their admirable
+soporifick quality, deserve to be taken notice of among the other
+_microscopical_ seeds of Vegetables: For first, though they grow in a Case
+or Hive oftentimes bigger then one of these Pictures of the _microscopical_
+appearance, yet are they for the most part so very little, that they exceed
+not the bulk of a small Nitt, being not above 1/32 part of an Inch in
+Diameter, whereas the Diameter of the Hive of them oftentimes exceeds two
+Inches, so that it is capable of containing near two hundred thousand, and
+so in all likelihood does contain a vast quantity, though perhaps not that
+number. Next, for their prettiness, they may be compar'd to any
+_microscopical_ seed I have yet seen; for they are of a dark brownish red
+colour, curiously Honey-comb'd all over with a very pretty variety of
+Net-work, or a small kind of imbosment of very orderly rais'd ridges, the
+surface of them looking not unlike the inside of a Beev's stomack. But that
+which makes it most considerable of all, is, the medicinal virtues of it,
+which are such as are not afforded us by any Mineral preparation; and that
+is for the procuring of sleep, a thing as necessary to the well-being of a
+creature as his meat, and that which refreshes both the voluntary and
+rational faculties, which, whil'st this affection has seis'd the body, are
+for the most part unmov'd, and at rest. And, methinks, Nature does seem to
+hint some very notable virtue or excellency in this Plant from the
+curiosity it has bestow'd upon it. First, in its flower, it is of the
+highest scarlet-Dye, which is indeed the prime and chiefest colour, and has
+been in all Ages of the world most highly esteem'd: Next, it has as much
+curiosity shew'd also in the husk or case of the seed, as any one Plant I
+have yet met withall; and thirdly, the very seeds themselves, the
+_Microscope_ discovers to be very curiously shap'd bodies; and lastly,
+Nature has taken such abundant care for the propagation of it, that one
+single seed grown into a Plant, is capable of bringing some hundred
+thousands of seeds.
+
+It were very worthy some able man's enquiry whether the intention of
+Nature, as to the secundary end of Animal and Vegetable substances might
+not be found out by some such characters and notable impressions as these,
+or from divers other circumstances, as the figure, colour, place, time of
+flourishing, springing and fading, duration, taste, smell, &c. For if such
+there are (as an able _Physician_ upon good grounds has given me cause to
+believe) we might then, insteed of studying Herbals (where so little is
+deliver'd of the virtues of a Plant, and less of truth) have recourse to
+the Book of Nature it self, and there find the most natural, usefull, and
+most effectual and specifick Medicines, of which we have amongst
+Vegetables, two very noble Instances to incourage such a hope, the one of
+the _Jesuite powder_ for the cure of _intermitting Feavers_, and the other
+of the juice of _Poppy_ for the curing the defect of sleeping.
+
+       *       *       *       *       *
+
+
+Observ. XXXI. _Of _Purslane-seed_._
+
+The Seeds of _Purslane_ seem of very notable shapes, appearing through the
+_Microscope_ shap'd somewhat like a _nautilus_ or _Porcelane_ shell, as may
+be seen in the XX. _Scheme_, it being a small body, coyl'd round in the
+manner of a Spiral, at the greater end whereof, which represents the mouth
+or orifice of the Shell, there is left a little white transparent
+substance, like a skin, represented by BBBB, which seems to have been the
+place whereunto the stem was join'd. The whole surface of this _Coclea_ or
+Shell, is cover'd over with abundance of little _prominencies_ or buttons
+very orderly rang'd into Spiral rows, the shape of each of which seem'd
+much to resemble a Wart upon a mans hand. The order, variety, and curiosity
+in the shape of this little seed, makes it a very pleasant object for the
+_Microscope_, one of them being cut asunder with a very sharp Penknife,
+discover'd this carved Casket to be of a brownish red, and somewhat
+transparent substance, and manifested the inside to be fill'd with a
+whitish green substance or pulp, the Bed wherein the seminal principle lies
+_invelop'd_.
+
+There are multitudes of other seeds which in shape represent or imitate the
+forms of divers other sorts of Shells: as the seed of _Scurvy-grass_ very
+much resembles the make of a _Concha Venerea_, a kind of Purcelane Shell;
+others represent several sorts of larger fruits, sweat Marjerome and
+Pot-marjerome represent Olives. Carret seeds are like a cleft of a Coco-Nut
+Husk, others are like Artificial things, as Succory seeds are like a Quiver
+full of Arrows, the seeds of _Amaranthus_ are of an exceeding lovely shape,
+somewhat like an Eye: The skin of the black and shrivled seeds of Onyons
+and Leeks, are all over knobbed like a Seals skin. Sorrel has a pretty
+black shining three-square seed, which is picked at both ends with three
+ridges, that are bent the whole length of it. It were almost endless to
+reckon up the several shapes, they are so many and so various; Leaving them
+therefore to the curious observer, I shall proceed to the Observations on
+the parts of Animals.
+
+       *       *       *       *       *
+
+
+Observ. XXXII. _Of the Figure of several sorts of _Hair_, and of the
+texture of the _skin_._
+
+Viewing some of the Hairs of my Head with a very good _Microscope_, I took
+notice of these particulars:
+
+1. That they were, for the most part, _Cylindrical_, some of them were
+somewhat _Prismatical_, but generally they were very neer round, such as
+are represented in the second Figure of the 5. _Scheme_, by the _Cylinders_
+EEE. nor could I find any that had sharp angules.
+
+2. That that part which was next the top, was bigger then that which was
+neerer the root.
+
+3. That they were all along from end to end transparent, though not very
+cleer, the end next the root appearing like a black transparent piece of
+Horn, the end next the top more brown, somewhat like transparent Horn.
+
+4. That the root of the Hairs were pretty smooth, tapering inwards, almost
+like a Parsneb; nor could I find that it had any filaments, or any other
+vessels, such as the _fibres_ of Plants.
+
+5. That the top when split (which is common in long Hair) appear'd like the
+end of a stick, beaten till it be all flitter'd, there being not onely two
+splinters, but sometimes half a score and more.
+
+6. That they were all, as farr as I was able to find, solid _Cylindrical_
+bodies, not pervious, like a Cane or Bulrush; nor could I find that they
+had any Pith, or distinction of Rind, or the like, such as I had observ'd
+in Horse-hairs, the Bristles of a Cat, the _Indian_ Deer's Hair, &c.
+
+_Observations on several other sorts of _Hair_._
+
+For the Brisles of a Hogg, I found them to be first a hard transparent
+horny substance, without the least appearance of pores or holes in it; and
+this I try'd with the greatest care I was able, cutting many of them with a
+very sharp Razor, so that they appear'd, even in the Glass, to have a
+pretty smooth surface, but somewhat waved by the sawing to and fro of the
+Razor, as is visible in the end of the _Prismatical_ body A of the same
+Figure; and then making trials with causing the light to be cast on them
+all the various ways I could think of, that was likely to make the pores
+appear, if there had been any, I was not able to discover any.
+
+Next, the Figure of the Brisles was very various, neither perfectly round,
+nor sharp edg'd, but _Prismatical_, with divers sides, and round angles, as
+appears in the Figure A. The bending of them in any part where they before
+appear'd cleer, would all flaw them, and make them look white.
+
+The Mustacheos of a Cat (part of one of which is represented by the short
+_Cylinder_ B of the same Figure) seem'd to have, all of them that I
+observ'd, a large pith in the middle, like the pith of an Elder, whose
+texture was so close, that I was not able to discover the least sign of
+pores; and those parts which seem to be pores, as they appear'd in one
+position to the light, in another I could find a manifest reflection to be
+cast from them.
+
+This I instance in, to hint that it is not safe to conclude any thing to be
+positively this or that, though it appear never so plain and likely when
+look'd on with a _Microscope_ in one posture, before the same be examin'd
+by placing it in several other positions.
+
+And this I take to be the reason why many have believed and asserted the
+Hairs of a man's head to be hollow, and like so many small pipes perforated
+from end to end.
+
+Now, though I grant that by an _Analogie_ one may suppose them so, and from
+the _Polonian_ disease one may believe them such, yet I think we have not
+the least encouragement to either from the _Microscope_, much less
+positively to assert them such. And perhaps the very essence of the _Plica
+Polonica_ may be the hairs growing hollow, and of an unnatural
+constitution.
+
+And as for the _Analogie_, though I am apt enough to think that the hairs
+of several Animals may be perforated somewhat like a Cane, or at least have
+a kind of pith in them, first, because they seem as 'twere a kind of
+Vegetable growing on an Animal, which growing, they say, remains a long
+while after the Animal is dead, and therefore should like other Vegetables
+have a pith; and secondly, because Horns and Feathers, and Porcupine's
+Quils, and Cats Bristles, and the long hairs of Horses, which come very
+neer the nature of a mans hair, seem all of them to have a kind of pith,
+and some of them to be porous, yet I think it not (in these cases, where we
+have such helps for the sense as the _Microscope_ affords) safe concluding
+or building on more then we sensibly know, since we may, with examining,
+find that Nature does in the make of the same kind of substance, often vary
+her method in framing of it: Instances enough to confirm this we may find
+in the Horns of several creatures: as what a vast difference is there
+between the Horns of an Oxe, and those of some sorts of Staggs as to their
+shape? and even in the hairs of several creatures, we find a vast
+difference, as the hair of a man's head seems, as I said before, long,
+_Cylindrical_ and sometime a little _Prismatical_, solid or impervious, and
+very small; the hair of an _Indian_ Deer (a part of the middle of which is
+described in the third Figure of the fifth _Scheme_, marked with F) is
+bigger in compass through all the middle of it, then the Bristle of an
+Hogg, but the end of it is smaller then the hair of any kind of Animal (as
+may be seen by the Figure G) the whole belly of it, which is about two or
+three Inches long, looks to the eye like a thread of course Canvass, that
+has been newly unwreath'd, it being all wav'd or bended to and fro, much
+after that manner, but through the _Microscope_, it appears all perforated
+from side to side, and Spongie, like a small kind of spongy Coral, which is
+often found upon the _English_ shores; but though I cut it transversly, I
+could not perceive that it had any pores that ran the long-way of the hair:
+the long hairs of Horses CC and D, seem _Cylindrical_ and somewhat pithy;
+the Bristles of a Cat B, are conical and pithy: the Quils of Porcupines and
+Hedghoggs, being cut transversly, have a whitish pith, in the manner of a
+Starr, or Spur-rowel: Piggs-hair (A) is somewhat _triagonal_, and seems to
+have neither pith nor pore: And other kinds of hair have quite a differing
+structure and form. And therefore I think it no way agreeable to a true
+natural Historian, to pretend to be so sharp-sighted, as to see what a
+pre-conceiv'd _Hypothesis_ tells them should be there, where another man,
+though perhaps as seeing, but not forestall'd, can discover no such matter.
+
+But to proceed; I observ'd several kind of hairs that had been Dyed, and
+found them to be a kind of horny _Cylinder_, being of much about the
+transparency of a pretty cleer piece of Oxe horn; these appear'd quite
+throughout ting'd with the colours they exhibited. And 'tis likely, that
+those hairs being boyl'd or steep'd in those very hot ting'd liquors in the
+Dye-fat, And the substance of the hair being much like that of an Oxes
+Horn, the penetrant liquor does so far mollifie and soften the substance,
+that it sinks into the very center of it, and so the ting'd parts come to
+be mix'd and united with the very body of the hair, and do not (as some
+have thought) only stick on upon the outward surface. And this, the boiling
+of Horn will make more probable; for we shall find by that action, that the
+water will insinuate it self to a pretty depth within the surface of it,
+especially if this penetrancy of the water be much helped by the Salts that
+are usually mix'd with the Dying liquors. Now, whereas Silk may be dyed or
+ting'd into all kind of colours without boiling or dipping into hot
+liquors, I ghess the reason to be two-fold: First, because the filaments,
+or small cylinders of Silk, are abundantly smaller and finer, and so have a
+much less depth to be penetrated then most kind of hairs; and next, because
+the substance or matter of Silk, is much more like a Glew then the
+substance of Hair is. And that I have reason to suppose: First, because
+when it is spun or drawn out of the Worm, it is a perfect glutinous
+substance, and very easily sticks and cleaves to any adjacent body, as I
+have several times observed, both in Silk-worms and Spiders. Next, because
+that I find that water does easily dissolve and mollifie the substance
+again, which is evident from their manner of ordering those bottoms or pods
+of the Silk-worm before they are able to unwind them. It is no great wonder
+therefore, if those Dyes or ting'd liquors do very quickly mollifie and
+tinge the surfaces of so small and so glutinous a body. And we need not
+wonder that the colours appear so lovely in the one, and so dull in the
+other, if we view but the ting'd cylinders of both kinds with a good
+_Microscope_; for whereas the substance of Hair, at best, is but a dirty
+duskish white somewhat transparent, the filaments of Silk have a most
+lovely transparency and cleerness, the difference between those two being
+not much less then that between a piece of Horn, and a piece of Crystal;
+the one yielding a bright and vivid reflection from the concave side of the
+cylinder, that is, from the concave surface of the Air that incompasses the
+back-part of the cylinder; the other yielding a dull and perturb'd
+reflection from the several _Heterogeneous_ parts that compose it. And this
+difference will be manifest enough to the eye, if you get a couple of small
+Cylinders, the smaller of Crystal Glass, the other of Horn, and then
+varnishing them over very thinly with some transparent colour, which will
+represent to the naked eye much the same kind of object which is
+represented to it from the filaments of Silk and Hair by the help of the
+_Microscope_. Now, since the threads of Silk and Serge are made up of a
+great number of these filaments, we may henceforth cease to wonder at the
+difference. From much the same reason proceeds the vivid and lovely colours
+of Feathers, wherein they very farr exceed the natural as well as
+Artificial colours of hair, of which I shall say more in its proper place.
+
+The Teguments indeed of creatures are all of them adapted to the peculiar
+use and convenience of that Animal which they inwrap; and very much also
+for the ornament and beauty of it, as will be most evident to any one that
+shall attentively consider the various kinds of cloathings wherewith most
+creatures are by Nature invested and cover'd. Thus I have observed, that
+the hair or furr of those Northern white Bears that inhabite the colder
+Regions, is exceeding thick and warm: the like have I observ'd of the hair
+of a _Greenland_ Deer, which being brought alive to _London_, I had the
+opportunity of viewing; its hair was so exceeding thick, long and soft,
+that I could hardly with my hand, grasp or take hold of his skin, and it
+seem'd so exceeding warm, as I had never met with any before. And as for
+the ornamentative use of them, it is most evident in a multitude of
+creatures, not onely for colour, as the Leopards, Cats, Rhein Deer, _&c_.
+but for the shape, as in Horses manes, Cats beards, and several other of
+the greater sort of terrestrial Animals, but is much more conspicuous, in
+the Vestments of Fishes, Birds, Insects, of which I shall by and by give
+some Instances.
+
+As for the skin, the _Microscope_ discovers as great a difference between
+the texture of those several kinds of Animals, as it does between their
+hairs; but all that I have yet taken notice of, when tann'd or dress'd, are
+of a Spongie nature, and seem to be constituted of an infinite company of
+small long _fibres_ or hairs, which look not unlike a heap of Tow or Okum;
+every of which _fibres_ seem to have been some part of a Muscle, and
+probably, whil'st the Animal was alive, might have its distinct function,
+and serve for the contraction and relaxation of the skin, and for the
+stretching and shrinking of it this or that way.
+
+And indeed, without such a kind of texture as this, which is very like that
+of _Spunk_ it would seem very strange, how any body so strong as the skin
+of an Animal usually is, and so close as it seems, whil'st the Animal is
+living, should be able to suffer so great an extension any ways, without at
+all hurting or dilacerating any part of it. But, since we are inform'd by
+the _Microscope_, that it consists of a great many small filaments, which
+are implicated, or intangled one within another, almost no otherwise then
+the hairs in a lock of Wool, or the flakes in a heap of Tow, though not
+altogether so loose, but the filaments are here and there twisted, as
+'twere, or interwoven, and here and there they join and unite with one
+another, so as indeed the whole skin seems to be but one piece, we need not
+much wonder: And though these _fibres_ appear not through a _Microscope_
+exactly jointed and contex'd, as in Sponge; yet, as I formerly hinted, I am
+apt to think, that could we find some way of discovering the texture of it,
+whil'st it invests the living Animal, or had some very easie way of
+separating the pulp or intercurrent juices, such as in all probability fill
+those _Interstitia_, without dilacerating, brusing, or otherwise spoiling
+the texture of it (as it seems to be very much by the ways of tanning and
+dressing now us'd) we might discover a much more curious texture then I
+have hitherto been able to find; perhaps somewhat like that of Sponges.
+
+That of _Chamoise_ Leather is indeed very much like that of _Spunk_, save
+onely that the _filaments_ seem nothing neer so even and round, nor
+altogether so small, nor has it so curious joints as _Spunk_ has, some of
+which I have lately discover'd like those of a Sponge, and perhaps all
+these three bodies may be of the same kind of substance, though two of them
+indeed are commonly accounted Vegetable (which, whether they be so or no, I
+shall not now dispute) But this seems common to all three, that they
+undergo a tanning or dressing, whereby the interspers'd juices are wasted
+and wash'd away before the texture of them can be discover'd.
+
+What their way is of dressing, or curing Sponges, I confess, I cannot
+learn; but the way of dressing _Spunk_, is, by boiling it a good while in a
+strong _Lixivium_, and then beating it very well; and the manner of
+dressing Leather is sufficiently known.
+
+It were indeed extremely desirable, if such a way could be found whereby
+the _Parenchyma_ or flesh of the Muscles, and several other parts of the
+body, might be wash'd, or wafted clean away, without vitiating the form of
+the _fibrous_ parts or vessells of it, for hereby the texture of thole
+parts, by the help of a good _Microscope_, might be most accurately found.
+
+But to digress no further, we may, from this discovery of the _Microscope_,
+plainly enough understand how the skin, though it looks so close as it
+does, comes to give a passage to so vast a quantity of _excrementitious_
+substances, as the diligent _Sanctorius_ has excellently observed it to do,
+in his _medicina statica_; for it seems very probable, from the texture
+after dressing, that there are an infinit of pores that every way pierce
+it, and that those pores are onely fill'd with some kind of juice, or some
+very pulpy soft substance, and thereby the steams may almost as easily find
+a passage through such a fluid _vehicle_ as the vaporous bubbles which are
+generated at the bottom of a Kettle of hot water do find a passage through
+that fluid _medium_ into the ambient Air.
+
+Nor is the skin of animals only thus pervious, but even those of vegetables
+also seem to be the same; for otherwise I cannot conceive why, if two
+sprigs of Rosemary (for Instance) be taken as exactly alike in all
+particulars as can be, and the one be set with the bottom in a Glass of
+water, and the other be set just without the Glass, but in the Air onely,
+though you stop the lower end of that in the Air very carefully with Wax,
+yet shall it presently almost wither, whereas the other that seems to have
+a supply from the subjacent water by its small pipes, or _microscopical_
+pores, preserves its greenness for many days, and sometimes weeks.
+
+Now, this to me, seems not likely to proceed from any other cause then the
+_avolation_ of the juice through the skin; for by the Wax, all those other
+pores of the stem are very firmly and closely stop'd up. And from the more
+or less porousness of the skins or rinds of Vegetables may, perhaps, be
+somewhat of the reason given, why they keep longer green, or sooner wither;
+for we may observe by the bladdering and craking of the leaves of Bays,
+Holly, Laurel, &c. that their skins are very close, and do not suffer so
+free a passage through them of the included juices.
+
+But of this, and of the Experiment of the Rosemary, I shall elsewhere more
+fully consider, seeming to me an extreme luciferous Experiment, such as
+seems indeed very plainly to prove the _Schematism_ or structure of
+Vegetables altogether _mechanical_, and as necessary, that (water and
+warmth being apply'd to the bottom of the sprig of a Plant) some of it
+should be carried upwards into the stem, and thence distributed into the
+leaves, as that the water of the _Thames_ covering the bottom of the Mills
+at the Bridge foot of _London_, and by the ebbing and flowing of it,
+passing strongly by them, should have some part of it convey'd to the
+Cesterns above, and thence into several houses and Cesterns up and down the
+City.
+
+       *       *       *       *       *
+
+
+Observ. XXXIII. _Of the _Scales_ of a _Soal_, and other Fishes._
+
+Having hinted somewhat of the skin and covering of terrestrial Animals, I
+shall next add an Observation I made on the skin and Scales of a _Soal_, a
+small Fish, commonly enough known; and here in Fishes, as well as other
+Animals, Nature follows its usual method, framing all parts so, as that
+they are both usefull and ornamental in all its composures, mingling
+_utile_ and _dulce_ together; and both these designs it seems to follow,
+though our unassisted senses are not able to peceive them: This is not
+onely manifest in the covering of this Fish, but in multitudes of others,
+which it would be too long to enumerate, witness particularly that small
+Sand Shell, which I mention'd in the XI. Observation, and infinite other
+small Shells and Scales, divers of which I have view'd. This skin I view'd,
+was flead from a pretty large _Soal_, and then expanded and dry'd, the
+inside of it, when dry, to the naked eye, look'd very like a piece of
+Canvass, but the _Microscope_ discover'd that texture to be nothing else,
+but the inner ends of those curious Scolop'd Scales I, I, I, in the second
+_Figure_ of the XXI. _Scheme_, namely, the part of GGGG (of the larger
+representation of a single Scale, in the first _Figure_ of the same
+_Scheme_) which on the back side, through an ordinary single Magnifying
+Glass, look'd not unlike the Tyles on an house.
+
+The outside of it, to the naked eye, exhibited nothing more of ornament,
+save the usual order of ranging the Scales into a _triagonal_ form, onely
+the edges seem'd a little to shine, the finger being rubb'd from the
+tail-wards towards the head, the Scales seem'd to stay and raze it; But
+through an ordinary Magnifying glass, it exhibited a most curiously carved
+and adorned surface, such as is visible in the second _Figure_, each of
+those (formerly almost imperceptible) Scales appearing much of the shape I,
+I, I, that is, they were round, and protuberant, and somewhat shap'd like a
+Scolop, the whole Scale being creas'd with curiously wav'd and indented
+ridges, with proportionable furrows between; each of which was terminated
+with a very sharp transparent bony substance, which, like so many small
+Turnpikes, seem'd to arm the edges.
+
+The back part KKK was the skin into which each of these Scales were very
+deeply fix'd, in the curious regular order, visible in the second _Figure_.
+The length and shape of the part of the Scale which was buried by the skin,
+is evidenced by the first _Figure_; which is the representation of one of
+them pluck'd out and view'd through a good _Microscope_, namely, the part
+LFGGFL, wherein is also more plainly to be seen, the manner of carving of
+the scolopt part of every particular Scale, how each ridge or barr EEE is
+alternately hollowed or engraven, and how every gutter between them is
+terminated with very transparent and hard pointed spikes, and how every
+other of these, as AAAA, are much longer then the interjacent ones, DDD.
+
+The texture or form also of the hidden part appears, namely, the middle
+part, GGG, seems to consist of a great number of small quills or pipes, by
+which, perhaps, the whole may be nourished; and the side parts FF consist
+of a more fibrous texture, though indeed the whole Scale seem'd to be of a
+very tough gristly substance like the larger Scales of other Fishes.
+
+The Scales of the skin of a Dog-fish (which is us'd by such as work in
+Wood, for the smoothing of their work, and consists plainly enough to the
+naked eye, of a great number off small horny points) through the
+_Microscope_ appear'd each of them curiously ridg'd, and very neatly
+carved; and indeed, you can hardly look on the scales of any Fish, but you
+may discover abundance of curiosity and beautifying; and not only in these
+Fishes, but in the shells and crusts or armour of most sorts of _Marine_
+Animals so invested.
+
+       *       *       *       *       *
+
+
+Observ. XXXIV. _Of the Sting of a Bee._
+
+The Sting of a _Bee_, delineated in the second Figure of the XVI. _Scheme_,
+seems to be a weapon of offence, and is as great an Instance, that Nature
+did realy intend revenge as any, and that first, because there seems to be
+no other use of it. Secondly, by reason of its admirable shape, seeming to
+be purposely shap'd for that very end. Thirdly, from the virulency of the
+liquor it ejects, and the sad effects and symptoms that follow it.
+
+But whatever be the use of it, certain it is, that the structure of it is
+very admirable; what it appears to the naked eye, I need not describe, the
+thing being known almost to every one, but it appears through the
+_Microscope_, to consist of two parts, the one a sheath, without a chape or
+top, shap'd almost like the Holster of a Pistol, beginning at d, and ending
+at b, this sheath I could most plainly perceive to be hollow, and to
+contain in it, both a Sword or Dart, and the poisonous liquor that causes
+the pain. The sheath or case seem'd to have several joints or settings
+together, marked by fghiklmno, it was arm'd moreover neer the top, with
+several crooks or forks (pqrst) on one side, and (pqrstu) on the other,
+each of which seem'd like so many Thorns growing on a briar, or rather like
+so many Cat's Claws; for the crooks themselves seem'd to be little sharp
+transparent points or claws, growing out of little _protuberancies_ on the
+side of the sheath, which, by observing the Figure diligently, is easie
+enough to be perceiv'd; and from several particulars, I suppose the Animal
+has a power of displaying them, and shutting them in again as it pleases,
+as a Cat does its claws, or as an Adder or Viper can its teeth or fangs.
+
+The other part of the Sting was the Sword, as I may so call it, which is
+sheath'd, as it were, in it, the top of which ab appears quite through at
+the smaller end, just as if the chape of the sheath of a Sword were lost,
+and the end of it appear'd beyond the Scabbard; the end of this Dart(a) was
+very sharp, and it was arm'd likewise with the like Tenterhooks or claws
+with those of the sheath, such as (vxy, xyzz) these crooks, I am very apt
+to think, can be clos'd up also, or laid flat to the sides of the Sword
+when it is drawn into the Scabbard, as I have several times observ'd it to
+be, and can be spred again or extended when ever the Animal pleases.
+
+The consideration of which very pretty structure, has hinted to me, that
+certainly the use of these claws seems to be very considerable, as to the
+main end of this Instrument, for the drawing in, and holding the sting in
+the flesh; for the point being very sharp, the top of the Sting or Dagger
+(ab) is very easily thrust into an Animal's body, which being once entred,
+the Bee, by endeavouring to pull it into the sheath, draws (by reason of
+the crooks (vxy) and (xyzz) which lay hold of the skin on either side) the
+top of the sheath (tsrv) into the skin after it, and the crooks t, s, and
+r, v, being entred, when the Bee endeavours to thrust out the top of the
+sting out of the sheath again, they lay hold of the skin on either side,
+and do not onely keep the sheath from sliding back, but helps the top
+inwards, and thus, by an alternate and successive retracting and emitting
+of the Sting in and out of the sheath, the little enraged creature by
+degrees makes his revengfull weapon pierce the toughest and thickest Hides
+of his enemies, in so much that some few of these stout and resolute
+soldiers with these little engines, do often put to flight a huge masty
+Bear, one of their deadly enemies, and thereby shew the world how much more
+considerable in Warr a few skilfull Engineers and resolute soldiers
+politickly order'd, that know how to manage such engines, are, then a vast
+unweildy rude force, that confides in, and acts onely by, its strength. But
+(to proceed) that he thus gets in his Sting into the skin, I conjecture,
+because, when I have observ'd this creature living, I have found it to move
+the Sting thus, to and fro, and thereby also, perhaps, does, as 'twere,
+pump or force out the poisonous liquor, and make it hang at the end of the
+sheath about b in a drop. The crooks, I suppose also to be the cause why
+these angry creatures, hastily removing themselves from their revenge, do
+often leave these weapons behind them, sheath'd, as 'twere, in the flesh,
+and, by that means, cause the painfull symptoms to be greater, and more
+lasting, which are very probably caus'd, partly by the piercing and tearing
+of the skin by the Sting, but chiefly by the corrosive and poisonous liquor
+that is by this Syringe-pipe convey'd among the sensitive parts thereof and
+thereby more easily gnaws and corrodes those tender _fibres_: As I have
+shewed in the description of a Nettle and of Cowhage.
+
+       *       *       *       *       *
+
+
+Observ. XXXV. _Of the contexture and shape of the particles of _Feathers_._
+
+Examining several sorts of _Feathers_, I took notice of these particulars
+in all sorts of wing-Feathers, especially in those which serv'd for the
+beating of the air in the action of flying.
+
+That the outward surface of the Quill and Stem was of a very hard, stiff,
+and horny substance, which is obvious enough, and that the part above the
+Quill was fill'd with a very white and light pith, and, with the
+_Microscope_, I found this pith to be nothing else, but a kind of natural
+_congeries_ of small bubbles, the films of which seem to be of the same
+substance with that of the Quill, that is, of a stiff transparent horny
+substance.
+
+Which particular seems to me, very worthy a more serious consideration; For
+here we may observe Nature, as 'twere, put to its shifts, to make a
+substance, which shall be both light enough, and very stiff and strong,
+without varying from its own establish'd principles, which we may observe
+to be such, that very strong bodies are for the most part very heavie also,
+a strength of the parts usually requiring a density, and a density a
+gravity; and therefore should Nature have made a body so broad and so
+strong as a Feather, almost, any other way then what it has taken, the
+gravity of it must necessarily have many times exceeded this; for this pith
+seems to be like so many stops or cross pieces in a long optical tube,
+which do very much contribute to the strength of the whole, the pores of
+which were such, as that they seem'd not to have any communication with one
+another, as I have elsewhere hinted.
+
+But the Mechanism of Nature is usually so excellent, that one and the same
+substance is adapted to serve for many ends. For the chief use of this,
+indeed, seems to be for the supply of nourishment to the downy or feathery
+part of the stem; for 'tis obvious enough in all sorts of Feathers, that
+'tis plac'd just under the roots of the branches that grow out of either
+side of the quill or stalk, and is exactly shap'd according to the ranking
+of those branches, coming no lower into the quill, then just the beginning
+of the downy branches, and growing onely on the under side of of the quill
+where those branches do so. Now, in a ripe Feather (as one may call it) it
+seems difficult to conceive how the _Succus nutritius_ should be convey'd
+to this pith; for it cannot, I think, be well imagin'd to pass through the
+substance of the quill, since, having examin'd it with the greatest
+diligence I was able, I could not find the least appearance of pores; but
+he that shall well examine an unripe or pinn'd Feather, will plainly enough
+perceive the Vessel for the conveyance of it to be the thin filmy pith (as
+'tis call'd) which passes through the middle of the quill.
+
+As for the make and contexture of the Down it self, it is indeed very rare
+and admirable, and such as I can hardly believe, that the like is to be
+discover'd in any other body in the world; for there is hardly a large
+Feather in the wing of a Bird, but contains neer a million of distinct
+parts, and every one of them shap'd in a most regular & admirable form,
+adapted to a particular Design: For examining a middle ciz'd Goose-quill, I
+easily enough found with my naked eye, that the main stem of it contain'd
+about 300. longer and more Downy branchings upon one side, and as many on
+the other of more stiff but somewhat shorter branchings. Many of these long
+and downy branchings, examining with an ordinary _Microscope_, I found
+divers of them to contain neer 1200. small leaves (as I may call them, such
+as EF of the first Figure of the 22. _Scheme_) and as many stalks on the
+other side, such as IK of the same Figure, each of the leaves or
+branchings, EF, seem'd to be divided into about sixteen or eighteen small
+joints, as may be seen plainly enough in the Figure, out of most of which
+there seem to grow small long _fibres_, such as are express'd in the
+Figure, each of them very proportionably shap'd according to its position,
+or place on the stalk EF; those on the under side of it, namely, 1, 2, 3,
+4, 5, 6, 7, 8, 9, &c. being much longer then those directly opposite to
+them on the upper; and divers of them, such as 2, 3, 4, 5, 6, 7, 8, 9, &c.
+were terminated with small crooks, much resembling those small crooks,
+which are visible enough to the naked eye, in the seed-buttons of
+Bur-docks. The stalks likewise, IK on the other side, seem'd divided into
+neer as many small knotted joints, but without any appearance of strings or
+crooks, each of them about the middle K, seem'd divided into two parts by a
+kind of fork, one side of which, namely, KL, was extended neer the length
+of KI, the other, M, was very short.
+
+The transverse Sections of the stems of these branchings, manifested the
+shape or figure of it to be much like INOE, which consisted of a horny skin
+or covering, and a white seemingly frothy pith, much like the make of the
+main stem of a Feather.
+
+The use of this strange kind of form, is indeed more admirable then all the
+rest, and such as deserves to be much more seriously examin'd and
+consider'd, then I have hitherto found time or ability to do; for
+certainly, it may very much instruct us in the nature of the Air,
+especially as to some properties of it.
+
+The stems of the Downy branches INOE, being rang'd in the order visible
+enough to the naked eye, at the distance of IF, or somewhat more, the
+_collateral_ stalks and leaves (if I may so call those bodies I newly
+described) are so rang'd, that the leaves or hairy stalks of the one side
+lie at top, or are incumbent on the stalks of the other, and cross each
+other, much after the manner express'd in the second Figure of the 22.
+_Scheme_, by which means every of those little hooked _fibres_ of the
+leaved stalk get between the naked stalks, and the stalks being full of
+knots, and a prety way dis-join'd, so as that the _fibres_ can easily get
+between them, the two parts are so closely and admirably woven together,
+that it is able to impede, for the greatest part, the transcursion of the
+Air; and though they are so exceeding small, as that the thickness of one
+of these stalks amounts not to a 500. part of an Inch, yet do they compose
+so strong a texture, as, notwithstanding the exceeding quick and violent
+beating of them against the Air, by the strength of the Birds wing, they
+firmly hold together. And it argues an admirable providence of Nature in
+the contrivance and fabrick of them; for their texture is such, that though
+by any external injury the parts of them are violently dis-joyn'd, so as
+that the leaves and stalks touch not one another, and consequently several
+of these rents would impede the Bird's flying; yet, for the most part, of
+themselves they readily re-join and re-contex themselves, and are easily by
+the Birds stroking the Feather, or drawing it through its Bill, all of them
+settled and woven into their former and natural posture; for there are such
+an infinite company of those small _fibres_ in the under side of the
+leaves, and most of them have such little crooks at their ends, that they
+readily catch and hold the stalks they touch.
+
+From which strange contexture, it seems rational to suppose that there is a
+certain kind of mesh or hole so small, that the Air will not very easily
+pass through it, as I hinted also in the sixth Observation about small
+Glass Canes, for otherwise it seems probable, that Nature would have drawn
+over some kind of thin film which should have covered all those almost
+square meshes or holes, there seeming through the _Microscope_ to be more
+then half of the surface of the Feather which is open and visibly pervious;
+which conjecture will yet seem more probable from the texture of the
+brushie wings of the _Tinea argentea_, or white Feather wing'd moth, which
+I shall anone describe. But Nature, that knows best its own laws, and the
+several properties of bodies, knows also best how to adapt and fit them to
+her designed ends, and whoso would know those properties, must endeavour to
+trace Nature in its working, and to see what course she observes. And this
+I suppose will be no inconsiderable advantage which the _Schematisms_ and
+Structures of Animate bodies will afford the diligent enquirer, namely,
+most sure and excellent instructions, both as to the practical part of
+_Mechanicks_ and to the _Theory_ and knowledge of the nature of the bodies
+and motions.
+
+       *       *       *       *       *
+
+
+Observ. XXXVI. _Of _Peacoks_, _Ducks_, and other _Feathers_ of   changeable
+colours._
+
+The parts of the Feathers of this glorious Bird appear, through the
+_Microscope_, no less gaudy then do the whole Feathers; for, as to the
+naked eye 'tis evident that the stem or quill of each Feather in the tail
+sends out multitudes of _Lateral_ branches, such as AB in the third Figure
+of the 22. _Scheme_ represents a small part of about 1/32 part of an Inch
+long, and each of the _lateral_ branches emit multitudes of little sprigs,
+threads or hairs on either side of them, such as CD, CD, CD, so each of
+those threads in the _Microscope_ appears a large long body, consisting of
+a multitude of bright reflecting parts, whose Figure 'tis no easie matter
+to determine, as he that examines it shall find; for every new position of
+it to the light makes it perfectly seem of another form and shape, and
+nothing what it appear'd a little before; nay, it appear'd very differing
+ofttimes from so seemingly inconsiderable a circumstance, that the
+interposing of ones hand between the light and it, makes a very great
+change, and the opening or shutting a Casement and the like, very much
+diversifies the appearance. And though, by examining the form of it very
+many ways, which would be tedious here to enumerate, I suppose I have
+discover'd the true Figure of it, yet oftentimes, upon looking on it in
+another posture, I have almost thought my former observations deficient,
+though indeed, upon further examination, I have found even those also to
+confirm them.
+
+These threads therefore I find to be a _congeries_ of small _Laminæ_ or
+plates, as eeeee, &c. each of them shap'd much like this of abcd, in the
+fourth _Figure_, the part ac being a ridge, prominency, or stem, and b and
+d the corners of two small thin Plates that grow unto the small stalk in
+the middle, so that they make a kind of little feather; each of these
+Plates lie one close to another, almost like a company of sloping ridge or
+gutter Tyles; they grow on each side of the stalk opposite to one another,
+by two and two, from top to bottom, in the manner express'd in the fifth
+Figure, the tops of the lower covering the roots of the next above them;
+the under side of each of these laminated bodies, is of a very dark and
+opacous substance, and suffers very few Rays to be trajected, but reflects
+them all toward that side from whence they come, much like the foil of a
+Looking-glass; but their upper sides seem to me to consist of a multitude
+of thin plated bodies, which are exceeding thin, and lie very close
+together, and thereby, like mother of Pearl shells, do not onely reflect a
+very brisk light, but tinge that light in a most curious manner; and by
+means of various positions, in respect of the light, they reflect back now
+one colour, and then another, and those most vividly.
+
+Now, that these colours are onely _fantastical_ ones, that is, such as
+arise immediately from the refractions of the light, I found by this, that
+water wetting these colour'd parts, destroy'd their colours, which seem'd
+to proceed from the alteration of the reflection and refraction. Now,
+though I was not able to see those hairs at all transparent by a common
+light, yet by looking on them against the Sun, I found them to be ting'd
+with a darkish red colour, nothing a-kin to the curious and lovely greens
+and blues they exhibited.
+
+What the reason of colour seems to be in such thin plated bodies, I have
+elsewhere shewn. But how water cast upon those threads destroys their
+colours, I suppose to be perform'd thus; The water falling upon these
+plated bodies from its having a greater congruity to Feathers then the Air,
+insinuates it self between those Plates, and so extrudes the strong
+reflecting Air, whence both these parts grow more transparent, as the
+_Microscope_ informs, and colourless also, at best retaining a very faint
+and dull colour. But this wet being wasted away by the continual
+evaporations and steams that pass through them from the Peacock, whil'st
+that Bird is yet alive, the colours again appear in their former luster,
+the _interstitia_ of these Plates being fill'd with the strongly reflecting
+Air.
+
+The beauteous and vivid colours of the Feathers of this Bird, being found
+to proceed from the curious and exceeding smalness and fineness of the
+reflecting parts, we have here the reason given us of all those gauderies
+in the apparel of other Birds also, and how they come to exceed the colours
+of all other kinds of Animals, besides Insects; for since (as we here, and
+elsewhere also shew) the vividness of a colour, depends upon the fineness
+and transparency of the reflecting and refracting parts; and since our
+_Microscope_ discovers to us, that the component parts of feathers are
+such, and that the hairs of Animals are otherwise; and since we find also
+by the Experiment of that Noble and most Excellent Person I formerly named;
+that the difference between Silk and Flax, as to its colour, is nothing
+else (for Flax reduc'd to a very great fineness of parts, both white and
+colour'd, appears as white and as vivid as any Silk, but loses that
+brightness and its Silken aspect as soon as it is twisted into thread, by
+reason that the component parts, though very small and fine, are yet
+pliable flakes, and not cylinders, and thence, by twisting, become united
+into one opacous body, whereas the threads of Silk and Feathers retain
+their lustre, by preserving their cylindrical form intire without mixing;
+so that each reflected and refracted beam that composes the gloss of Silk,
+preserves its own property of modulating the light intire); And since we
+find the same confirm'd by many other Experiments elsewhere mentioned, I
+think we may safely conclude this for an Axiome, that wheresoever we meet
+with transparent bodies, spun out into very fine parts, either cleer, or
+any ways ting'd, the colours resulting from such a _composition_ must
+necessarily be very glorious, vivid, and cleer, like those of Silk and
+Feathers. This may perhaps hint some usefull way of making other bodies,
+besides Silk, be susceptible of bright tinctures, but of this onely by the
+by.
+
+The changeable colour'd Feathers also of Ducks, and several other Birds, I
+have found by examination with my _Microscope_, to proceed from much the
+same causes and textures.
+
+       *       *       *       *       *
+
+
+Observ. XXXVII. _Of the Feet of _Flies_, and several other _Insects_._
+
+The foot of a Fly (delineated in the first _Figure_ of the 23. _Scheme_,
+which represents three joints, the two Tallons, and the two Pattens in a
+flat posture; and in the second _Figure_ of the same _Scheme_, which
+represents onely one joint, the Tallons and Pattens in another posture) is
+of a most admirable and curious contrivance, for by this the Flies are
+inabled to walk against the sides of Glass, perpendicularly upwards, and to
+contain themselves in that posture as long as they please; nay, to walk and
+suspend themselves against the under surface of many bodies, as the ceiling
+of a room, or the like, and this with as great a seeming facility and
+firmness, as if they were a kind of _Antipodes_, and had a _tendency_
+upwards, as we are sure they have the contrary, which they also evidently
+discover, in that they cannot make themselves so light, as to stick or
+suspend themselves on the under surface of a Glass well polish'd and
+cleans'd; their suspension therefore is wholly to be ascrib'd to some
+Mechanical contrivance in their feet; which, what it is, we shall in brief
+explain, by shewing, that its Mechanism consists principally in two parts,
+that is, first its two Claws, or Tallons, and secondly, two Palms, Pattens,
+or Soles.
+
+The two Tallons are very large, in proportion to the foot, and handsomly
+shap'd in the manner describ'd in the _Figures_, by AB, and AC, the bigger
+part of them from A to _dd_, is all hairy, or brisled, but toward the top,
+at C and B smooth, the tops or points, which seem very sharp turning
+downwards and inwards, are each of them mov'd on a joint at A, by which the
+Fly is able to open or shut them at pleasure, so that the points B and C
+being entered in any pores, and the Fly endeavouring to shut them, the
+Claws not onely draw one against another, and so fasten each other, but
+they draw the whole foot, GGADD forward, so that on a soft footing, the
+tenters or points GGGG, (whereof a Fly has about ten in each foot, to wit,
+two in every joint) run into the pores, if they find any, or at least make
+their way; and this is sensible to the naked eye, in the feet of a
+_Chafer_, which, if he be suffer'd to creep over the hand, or any other
+part of the skin of ones body, does make his steps as sensible to the touch
+as the sight.
+
+But this contrivance, as it often fails the _Chafer_, when he walks on hard
+and close bodies, so would it also our Fly, though he be a much lesser, and
+nimbler creature, and therefore Nature has furnish'd his foot with another
+_additament_ much more curious and admirable, and that is, with a couple of
+Palms, Pattens or Soles DD, the structure of which is this:
+
+From the bottom or under part of the last joint of his foot, K, arise two
+small thin plated horny substances, each consisting of two flat pieces, DD,
+which seem to be flexible, like the covers of a Book, about FF, by which
+means, the plains of the two sides EE, do not always lie in the same plain,
+but may be sometimes shut closer, and so each of them may take a little
+hold themselves on a body; but that is not all, for the under sides of
+these Soles are all beset with small brisles, or tenters, like the Wire
+teeth of a Card used for working Wool, the points of all which tend
+forwards, hence the two Tallons drawing the feet forwards, as I before
+hinted, and these being applied to the surface of the body with all the
+points looking the contrary way, that is, forwards and outwards, if there
+be any irregularity or yielding in the surface of the body, the Fly
+suspends it self very firmly and easily, without the access or need of any
+such Sponges fill'd with an imaginary _gluten_, as many have, for want of
+good Glasses, perhaps, or a troublesome and diligent examination, suppos'd.
+
+Now, that the Fly is able to walk on Glass, proceeds partly from some
+ruggedness of the surface: and chiefly from a kind of tarnish, or dirty
+smoaky substance, which adheres to the surface of that very hard body; and
+though the pointed parts cannot penetrate the substance of Glass, yet may
+they find pores enough in the tarnish, or at least make them.
+
+This Structure I somewhat the more diligently survey'd, because I could not
+well comprehend, how, if there were such a glutinous matter in those
+supposed Sponges, as most (that have observ'd that Object in a
+_Microscope_) have hitherto believ'd, how, I say, the Fly could so readily
+unglew and loosen its feet: and, because I have not found any other
+creature to have a contrivance any ways like it, and chiefly, that we might
+not be cast upon unintelligible explications of the _Phænomena_ of Nature,
+at least others then the true ones, where our senses were able to furnish
+us with an intelligible, rationall and true one.
+
+Somewhat a like contrivance to this of Flies shall we find in most other
+Animals, such as all kinds of Flies and case-wing'd creatures; nay, in a
+Flea, an Animal abundantly smaller then this Fly. Other creatures, as
+Mites, the Land-Crab, &c. have onely one small very sharp Tallon at the end
+of each of their legs, which all drawing towards the center or middle of
+their body, inable these exceeding light bodies to suspend and fasten
+themselves to almost any surface.
+
+Which how they are able to do, will not seem strange, if we consider,
+first, how little body there is in one of these creatures compar'd to their
+superficies, or outside, their thickness, perhaps, oftentimes, not
+amounting to the hundredth part of an Inch: Next, the strength and agility
+of these creatures compar'd to their bulk, being, proportionable to their
+bulk, perhaps, an hundred times stronger then an Horse or Man. And thirdly,
+if we consider that Nature does always appropriate the instruments, so as
+they are the most fit and convenient to perform their offices, and the most
+simple and plain that possibly can be; this we may see further verify'd
+also in the foot of a Louse which is very much differing from those I have
+been describing, but more convenient and necessary for the place of its
+habitation, each of his leggs being footed with a couple of small claws
+which he can open or shut at pleasure, shap'd almost like the claws of a
+Lobster or Crab, but with appropriated contrivances for his peculiar life,
+which being to move its body to and fro upon the hairs of the creature it
+inhabits, Nature has furnish'd one of its claws with joints, almost like
+the joints of a man's fingers, so as thereby it is able to encompass or
+grasp a hair as firmly as a man can a stick or rope.
+
+Nor, is there a less admirable and wonderfull _Mechanism_ in the foot of a
+Spider, whereby he is able to spin, weave, and climb, or run on his curious
+transparent clew, of which I shall say more in the description of that
+Animal.
+
+And to conclude, we shall in all things find, that Nature does not onely
+work Mechanically, but by such excellent and most compendious, as well as
+stupendious contrivances, that it were impossible for all the reason in the
+world to find out any contrivance to do the same thing that should have
+more convenient properties. And can any be so sottish, as to think all
+those things the productions of chance? Certainly, either their
+Ratiocination must be extremely depraved, or they did never attentively
+consider and contemplate the Works of the Al-mighty.
+
+       *       *       *       *       *
+
+
+Observ. XXXVIII. _Of the Structure and motion of the Wings of _Flies_._
+
+The Wings of all kinds of Insects, are, for the most part, very beautifull
+Objects, and afford no less pleasing an Object to the mind to speculate
+upon, then to the eye to behold. This of the blue Fly, among the rest,
+wants not its peculiar ornaments and contrivances; it grows out of the
+_Thorax_, or middle part of the body of a Fly, and is seated a little
+beyond the center of gravity in the body towards the head, but that
+_Excentricly_ is curiously balanc'd; first, by the expanded _Area_ of the
+wings which lies all more backwards then the root, by the motion of them,
+whereby the center of their vibration is much more backwards towards the
+tail of the Fly then the root of the wing is. What the vibrative motion of
+the wings is, and after what manner they are moved, I have endeavoured by
+many trials to find out: And first for the manner of their motion, I
+endeavoured to observe several of those kind of small Spinning Flies, which
+will naturally suspend themselves, as it were, pois'd and steady in one
+place of the air, without rising or falling, or moving forwards or
+backwards; for by looking down on those, I could by a kind of faint shadow,
+perceive the utmost extremes of the vibrative motion of their wings, which
+shadow, whil'st they so endeavoured to suspend themselves, was not very
+long, but when they endeavour'd to flie forwards, it was somewhat longer;
+next, I tried it, by fixing the leggs of a Fly upon the top of the stalk of
+a feather, with Glew, Wax, &c. and then making it endeavour to flie away;
+for being thereby able to view it in any posture, I collected that the
+motion of the wing was after this manner. The extreme limits of the
+vibrations were usually somewhat about the length of the body distant from
+one another, oftentimes shorter, and sometimes also longer; that the
+formost limit was usually a little above the back, and the hinder somwhat
+beneath the belly; between which two limits, if one may ghess by the sound,
+the wing seem'd to be mov'd forwards and backwards with an equal velocity:
+And if one may (from the shadow or faint representation the wings afforded,
+and from the consideration of the nature of the thing) ghess at the posture
+or manner of the wings moving between them, it seem'd to be this: The wing
+being suppos'd placed in the upmost limit, seems to be put so that the
+plain of it lies almost _horizontal_, but onely the forepart does dip a
+little, or is somewhat more deprest; in this position is the wing vibrated
+or mov'd to the lower limit, being almost arrived at the lower limit, the
+hinder part of the wing moving somewhat faster then the former, the _Area_,
+of the wing begins to dip behind, and in that posture seems it to be mov'd
+to the upper limit back again, and thence back again in the first posture,
+the former part of the _Area_ dipping again, as it is moved downwards by
+means of the quicker motion of the main stem which terminates or edges the
+forepart of the wing. And these vibrations or motions to and fro between
+the two limits seem so swift, that 'tis very probable (from the sound it
+affords, if it be compar'd with the vibration of a musical string, tun'd
+unison to it) it makes many hundreds, if not some thousands of vibrations
+in a second minute of time. And, if we may be allow'd to ghess by the
+sound, the wing of a Bee is yet more swift, for the tone is much more
+acute, and that, in all likelihood, proceeds from the exceeding swift
+beating of the air by the small wing. And it seems the more likely too,
+because the wing of a Bee is less in proportion to its body, then the other
+wing to the body of a Fly; so that for ought I know, it may be one of the
+quickest vibrating _spontaneous_ motions of any in the world; and though
+perhaps there may be many Flies in other places that afford a yet more
+shrill note with their wings, yet 'tis most probable that the quickest
+vibrating _spontaneous_ motion is to be found in the wing of some creature.
+Now, if we consider the exceeding quickness of these Animal spirits that
+must cause these motions, we cannot chuse but admire the exceeding
+vividness of the governing faculty or _Anima_ of the Insect, which is able
+to dispose and regulate so the the motive faculties, as to cause every
+peculiar organ, not onely to move or act so quick, but to do it also so
+regularly.
+
+Whil'st I was examining and considering the curious _Mechanism_ of the
+wings, I observ'd that under the wings of most kind of Flies, Bees, &c.
+there were plac'd certain _pendulums_ or extended drops (as I may so call
+them from their resembling motion and figure) for they much resembled a
+long hanging drop of some transparent viscous liquor; and I observed them
+constantly to move just before the wings of the Fly began to move, so that
+at the first sight I could not but ghess, that there was some excellent
+use, as to the regulation of the motion of the wing, and did phancy, that
+it might be something like the handle of a Cock, which by vibrating to and
+fro, might, as 'twere, open and shut the Cock, and thereby give a passage
+to the determinate influences into the Muscles; afterwards, upon some other
+trials, I suppos'd that they might be for some use in respiration, which
+for many reasons I suppose those Animals to use, and, me thought, it was
+not very improbable, but that they might have convenient passages under the
+wings for the emitting, at least, of the air, if not admitting, as in the
+gills of Fishes is most evident; or, perhaps, this _Pendulum_ might be
+somewhat like the staff to a Pump, whereby these creatures might exercise
+their _Analogous_ lungs, and not only draw in, but force out, the air they
+live by: but these were but conjectures, and upon further examination
+seem'd less probable.
+
+The fabrick of the wing, as it appears through a moderately magnifying
+_Microscope_, seems to be a body consisting of two parts, as is visible in
+the 4. _Figure_ of the 23. _Scheme_; and by the 2. _Figure_ of the 26.
+_Scheme_; the one is a quilly or finny substance, consisting of several
+long, slender and variously bended quills or wires, something resembling
+the veins of leaves; these are, as 'twere, the finns or quills which
+stiffen the whole _Area_, and keep the other part distended, which is a
+very thin transparent skin or membrane variously folded, and platted, but
+not very regularly, and is besides exceeding thickly bestuck with
+innumerable small bristles, which are onely perceptible by the bigger
+magnifying _Microscope_, and not with that neither, but with a very
+convenient augmentation of sky-light projected on the Object with a burning
+Glass, as I have elsewhere shew'd, or by looking through it against the
+light.
+
+In steed of these small hairs, in several other Flies, there are infinite
+of small Feathers, which cover both the under and upper sides of this thin
+film as in almost all the sorts of Butterflies and Moths: and those small
+parts are not onely shap'd very much like the feathers of Birds, but like
+those variegated with all the variety of curious bright and vivid colours
+imaginable; and those feathers are likewise so admirably and delicately
+rang'd, as to compose very fine flourishings and ornamental paintings, like
+_Turkie_ and _Persian_ Carpets, but of far more surpassing beauty, as is
+evident enough to the naked eye, in the painted wings of Butterflies, but
+much more through an ordinary _Microscope_.
+
+Intermingled likewise with these hairs, may be perceived multitudes of
+little pits, or black spots, in the exended membrane, which seem to be the
+root of the hairs that grow on the other side; these two bodies seem
+dispers'd over the whole surface of the wing.
+
+The hairs are best perceiv'd, by looking through it against the light, or,
+by laying the wing upon a very white piece of Paper, in a convenient light,
+for thereby every little hair most manifestly appears; a _Specimen_ of
+which you may observe drawn in the fourth _Figure_ of the 23. _Scheme_, AB,
+CD, EF whereof represent some parts of the bones or quills of the wing,
+each of which you may perceive to be cover'd over with a multitude of
+scales, or bristles, the former AB, is the biggest stem of all the wing,
+and may be properly enough call'd the cut-air, it being that which
+terminates and stiffens the formost edge of the wing; the fore-edge of this
+is arm'd with a multitude of little brisles, or Tenter-hooks, in some
+standing regular and in order, in others not; all the points of which are
+directed from the body towards the tip of the wing, nor is this edge onely
+thus fring'd, but even all the whole edge of the wing is covered with a
+small fringe, consisting of short and more slender brisles.
+
+This Subject, had I time, would afford excellent matter for the
+contemplation of the nature of wings and of flying, but, because I may,
+perhaps, get a more convenient time to prosecute that speculation, and
+recollect several Observations that I have made of that particular. I shall
+at present proceed to
+
+       *       *       *       *       *
+
+
+Observ. XXXIX. _Of the Eyes and Head of a _Grey drone-Fly_,
+and of several other creatures._
+
+I took a large grey _Drone-Fly_, that had a large head, but a small and
+slender body in proportion to it, and cutting off its head, I fix'd it with
+the forepart or face upwards upon my Object Plate (this I made choice of
+rather then the head of a great blue Fly, because my enquiry being now
+about the eyes, I found this Fly to have, first the biggest clusters of
+eyes in proportion to his head, of any small kind of Fly that I have yet
+seen, it being somewhat inclining towards the make of the large
+_Dragon-Flies_. Next, because there is a greater variety in the knobs or
+balls of each cluster, then is of any small Fly.) Then examining it
+according to my usual manner, by varying the degrees of light, and altering
+its position to each kinde of light, I drew that representation of it which
+is delineated in the 24. _Scheme_, and found these things to be as plain
+and evident, as notable and pleasant.
+
+_First_, that the greatest part of the face, nay, of the head, was nothing
+else but two large and _protuberant_ bunches, or _prominent_ parts, ABCDEA,
+the surface of each of which was all cover'd over, or shap'd into a
+multitude of small _Hemispheres_, plac'd in a _triagonal_ order, that being
+the closest and most compacted, and in that order, rang'd over the whole
+surface of the eye in very lovely rows, between each of which, as is
+necessary, were left long and regular trenches, the bottoms of every of
+which, were perfectly intire and not at all perforated or drill'd through,
+which I most certainly was assured of, by the regularly reflected Image of
+certain Objects which I mov'd to and fro between the head and the light.
+And by examining the _Cornea_ or outward skin, after I had stript it off
+from the several substances that lay within it, and by looking both upon
+the inside and against the light.
+
+_Next_, that of those multitudes of _Hemispheres_, there were observable
+two degrees of bigness, the half of them that were lowermost, and look'd
+toward the ground or their own leggs, namely, CDE, CDE being a pretty deal
+smaller then the other, namely, ABCE, ABCE, that look'd upward, and
+side-ways, or foreright, and backward, which variety I have not found in
+any other small Fly.
+
+_Thirdly_, that every one of these _Hemispheres_, as they seem'd to be
+pretty neer the true shape of a _Hemisphere_, so was the surface exceeding
+smooth and regular, reflecting as exact, regular, and perfect an Image of
+any Object from the surface of them, as a small Ball of Quick-silver of
+that bigness would do, but nothing neer so vivid, the reflection from these
+being very languid, much like the reflection from the outside of Water,
+Glass, Crystal, &c. In so much that in each of these _Hemispheres_, I have
+been able to discover a Land-scape of those things which lay before my
+window, one thing of which was a large Tree, whose trunk and top I could
+plainly discover, as I could also the parts of my window, and my hand and
+fingers, if I held it between the Window and the Object; a small draught of
+nineteen of which, as they appear'd in the bigger Magnifying-glass to
+reflect the Image of the two windows of my Chamber, are delineated in the
+third _Figure_ of the 23. _Scheme_.
+
+_Fourthly_, that these rows were so dispos'd, that there was no quarter
+visible from his head that there was not some of these _Hemispheres_
+directed against, so that a Fly may be truly said to have _an eye every
+way_, and to be really _circumspect_. And it was further observable, that
+that way where the trunk of his body did hinder his prospect backward,
+these _protuberances_ were elevated, as it were, above the plain of his
+shoulders and back, so that he was able to see backwards also over his
+back.
+
+_Fifthly_, in living Flies, I have observ'd, that when any small mote or
+dust, which flies up and down the air, chances to light upon any part of
+these knobs, as it is sure to stick firmly to it and not fall, though
+through the _Microscope_ it appears like a large stone or stick (which one
+would admire, especially since it is no ways probable that there is any wet
+or glutinous matter upon these _Hemispheres_, but I hope I shall render the
+reason in another place) so the Fly presently makes use of his two
+fore-feet in stead of eye-lids, with which, as with two Brooms or Brushes,
+they being all bestuck with Brisles, he often sweeps or brushes off what
+ever hinders the prospect of any of his _Hemispheres_, and then, to free
+his leggs from that dirt, he rubs them one against another, the pointed
+Brisles or Tenters of which looking both one way, the rubbing of them to
+and fro one against another, does cleanse them in the same manner as I have
+observ'd those that Card Wool, to cleanse their Cards, by placing their
+Cards, so as the teeth of both look the same way, and then rubbing them one
+against another. In the very same manner do they brush and cleanse their
+bodies and wings, as I shall by and by shew; other creatures have other
+contrivances for the cleansing and cleering their eyes.
+
+_Sixthly_ that the number of the _Pearls_ or _Hemispheres_ in the clusters
+of this Fly, was neer 14000. which I judged by numbering certain rows of
+them several ways, and casting up the whole content, accounting each
+cluster to contain about seven thousand Pearls, three thousand of which
+were of a size, and consequently the rows not so thick, and the foure
+thousand I accounted to be the number of the smaller Pearls next the feet
+and _proboscis_. Other Animals I observ'd to have yet a greater number, as
+the _Dragon-Fly_ or _Adderbolt_: And others to have a much less company, as
+an _Ant_, &c. and several other small Flies and Insects.
+
+_Seventhly_, that the order of these eies or _Hemispheres_ was altogether
+curious and admirable, they being plac'd in all kind of Flies, and _aerial_
+animals, in a most curious and regular ordination of triangular rows, in
+which order they are rang'd the neerest together that possibly they can,
+and consequently leave the least pits or trenches between them. But in
+_Shrimps_, _Crawfishes_, _Lobsters_, and such kinds of _Crustaceous_ water
+Animals, I have yet observ'd them rang'd in a quadrangular order, the rows
+cutting each other at right angles, which as it admits of a less number of
+Pearls in equal surfaces; so have those creatures a recompence made them,
+by having their eyes a little movable in their heads, which the other
+altogether want. So infinitely wise and provident do we find all the
+Dispensations in Nature, that certainly _Epicurus_, and his followers, must
+very little have consider'd them, who ascrib'd those things to the
+production of chance, that wil, to a more attentive considerer, appear the
+products of the highest Wisdom and Providence.
+
+Upon the Anatomy or Dissection of the Head, I observ'd these particulars:
+
+First, that this outward skin, like the _Cornea_ of the eyes of the greater
+Animals, was both flexible and transparent, and seem'd, through the
+_Microscope_ perfectly to resemble the very substance of the _Cornea_ of a
+man's eye; for having cut out the cluster, and remov'd the dark and
+_mucous_ stuff that is subjacent to it, I could see it transparent like a
+thin piece of skin, having as many cavities in the inside of it, and rang'd
+in the same order as it had _protuberances_ on the outside, and this
+propriety, I found the same in all the Animals that had it, whether Flies
+or Shell-Fish.
+
+Secondly, I found that all Animals that I have observ'd with those kind of
+eyes; have within this _Cornea_, a certain cleer liquor or juice, though in
+a very little quantity, and,
+
+I observ'd thirdly, that within that cleer liquor, they had a kind of dark
+_mucous_ lining, which was all spread round within the cavity of the
+clutter, and seem'd very neer adjoining to it, the colour of which, in some
+Flies, was grey; in others, black, in others red; in others, of a mix'd
+colour; in others, spotted; and that the whole clusters, when look'd on
+whilst the Animal was living, or but newly kill'd, appear'd of the same
+colour that this coat (as I may so call it) appear'd of, when that outward
+skin, or _Cornea_, was remov'd.
+
+Fourthly, that the rest of the capacity of the clusters was in some, as in
+Dragon Flies, &c. hollow, or empty; in others fill'd with some kind of
+substance; in blue Flies, with a reddish musculous substance, with _fibres_
+tending from the center or bottom outwards; and divers other, with various
+and differing kinds of substances.
+
+That this curious contrivance is the organ of sight to all those various
+_Crustaceous_ Animals, which are furnish'd with it, I think we need not
+doubt, if we consider but the several congruities it has with the eyes of
+greater creatures.
+
+As first, that it is furnish'd with a _Cornea_, with a _transparent
+humour_, and with a _uvea_ or _retina_, that the Figure of each of the
+small _Hemispheres_ are very _Spherical_, exactly polish'd, and most vivid,
+lively and plump, when the Animal is living, as in greater Animals, and in
+like manner dull, flaccid, and irregular, or shrunk, when the Animal is
+dead.
+
+Next, that those creatures that are furnish'd with it, have no other organs
+that have any resemblance to the known eyes of other creatures.
+
+Thirdly, that those which they call the eyes of Crabs, Lobsters, Shrimps,
+and the like, and are really so, are _Hemispher'd_, almost in the same
+manner as these of Flies are. And that they really are so, I have very
+often try'd, by cutting off these little movable knobs, and putting the
+creature again into the water, that it would swim to and fro, and move up
+and down as well as before, but would often hit it self against the rocks
+or stones; and though I put my hand just before its head, it would not at
+all start or fly back till I touch'd it, whereas whil'st those were
+remaining, it would start back, and avoid my hand or a stick at a good
+distance before it touch'd it. And if in _crustaceous_ Sea-animals, then it
+seems very probable also, that these knobs are the eyes in _crustaceous_
+Insects, which are also of the same kind, onely in a higher and more active
+Element; this the conformity or congruity of many other parts common to
+either of them, will strongly argue, their _crustaceous_ armour, their
+number of leggs, which are six, beside the two great claws, which answer to
+the wings in Insects; and in all kind of Spiders, as also in many other
+Insects that want wings, we shall find the compleat number of them, and not
+onely the number, but the very shape, figure, joints, and claws of Lobsters
+and Crabs, as is evident in Scorpions and Spiders, as is visible in the
+second _Figure_ of the 31. _Scheme_, and in the little Mite-worm, which I
+call a Land-crab, describ'd in the second Figure of the 33. _Scheme_, but
+in their manner of generation being oviparous, &c. And it were very worthy
+observation, whether there be not some kinds of transformation and
+metamorphosis in the several states of _crustaceous_ water-animals, as
+there is in several sorts of Insects; for if such could be met with, the
+progress of the variations would be much more conspicuous in those larger
+Animals, then they can be in any kind of Insects our colder Climate
+affords.
+
+These being their eyes, it affords us a very pretty Speculation to
+contemplate their manner of vision, which, as it is very differing from
+that of _biocular_ Animals, so is it not less admirable.
+
+That each of these Pearls or _Hemispheres_ is a perfect eye, I think we
+need not doubt, if we consider onely the outside or figure of any one of
+them, for they being each of them cover'd with a transparent protuberant
+_Cornea_, and containing a liquor within them, resembling the watry or
+glassie humours of the eye, must necessarily refract all the parallel Rays
+that fall on them out of the air, into a point not farr distant within
+them, where (in all probability) the _Retina_ of the eye is placed, and
+that opacous, dark, and mucous inward coat that (I formerly shew'd) I found
+to subtend the concave part of the cluster is very likely to be that
+_tunicle_ or coat, it appearing through the _Microscope_ to be plac'd a
+little more than a Diameter of those Pearls below or within the _tunica
+cornea_. And if so, then is there in all probability, a little Picture or
+Image of the objects without, painted or made at the bottom of the _Retina_
+against every one of those Pearls, so that there are as many impressions on
+the _Retina_ or opacous skin, as there are Pearls or _Hemispheres_ on the
+cluster. But because it is impossible for any protuberant surface
+whatsoever, whether _sphærial_ or other, so to refract the Rays that come
+from farr remote _lateral_ points of any Object as to collect them again,
+and unite them each in a distinct point, and that onely those Rays which
+come from some point that lies in the _Axis_ of the Figure produc'd, are so
+accurately refracted to one and the same point again, and that the
+_lateral_ Rays, the further they are remov'd, the more imperfect is their
+refracted confluence; It follows therefore, that onely the Picture of those
+parts of the external objects that lie in, or neer, the _Axis_ of each
+_Hemisphere_, are discernably painted or made on the _Retina_ of each
+_Hemisphere_, and that therefore each of them can distinctly sensate or see
+onely those parts which are very neer perpendicularly oppos'd to it, or lie
+in or neer its optick _Axis_. Now, though there may be by each of these
+eye-pearls, a representation to the Animal of a whole _Hemisphere_ in the
+same manner as in a man's eye there is a picture or sensation in the
+_Retina_ of all the objects lying almost in an _Hemisphere_; yet, as in a
+man's eye also, there are but some very few points which liyng in, or neer,
+the optick _Axis_ are distinctly discern'd: So there may be multitudes of
+Pictures made of an Object in the several Pearls, and yet but one, or some
+very few that are distinct; The representation of any object that is made
+in any other Pearl, but that which is directly, or very neer directly,
+oppos'd, being altogether confus'd and unable to produce a distinct vision.
+
+So that we see, that though it has pleas'd the All-wise Creator, to indue
+this creature with such multitudes of eyes, yet has he not indued it with
+the faculty of seeing more then another creature; for whereas this cannot
+move his head, at least can move it very little, without moving his whole
+body, _biocular_ creatures can in an instant (or _the twinkling of an eye_,
+which, being very quick, is vulgarly used in the same signification) move
+their eyes so as to direct the optick _Axis_ to any point; nor is it
+probable, that they are able to see attentively at one time more then one
+Physical point; for though there be a distinct Image made in every eye, yet
+'tis very likely, that the observing faculty is only imploy'd about some
+one object for which they have most concern.
+
+Now, as we accurately distinguish the site or position of an Object by the
+motion of the Muscles of the eye requisite to put the optick Line in a
+direct position, and confusedly by the position of the imperfect Picture of
+the object at the bottom of the eye; so are these _crustaceous_ creatures
+able to judge confusedly of the position of objects by the Picture or
+impression made at the bottom of the opposite Pearl, and distinctly by the
+removal of the attentive or observing faculty, from one Pearl to another,
+but what this faculty is, as it requires another place, so a much deeper
+speculation. Now, because it were impossible, even with this multitude of
+eye-balls, to see any object distinct (for as I hinted before, onely those
+parts that lay in, or very neer, the optick Lines could be so) the
+Infinitely wise Creator has not left the creature without a power of moving
+the head a little in _Aerial crustaceous_ animals, and the very eyes also
+in _crustaceous_ Sea-animals; so that by these means they are inabled to
+direct some optick line or other against any object, and by that means they
+have the visive faculty as compleat as any Animal that can move its eyes.
+
+Distances of Objects also, 'tis very likely they distinguish, partly by the
+consonant impressions made in some two convenient Pearls, one in each
+cluster; for, according as those congruous impressions affect, two Pearls
+neerer approach'd to each other, the neerer is the Object, and the farther
+they are distant, the more distant is the Object: partly also by the
+alteration of each Pearl, requisite to make the Sensation or Picture
+perfect; for 'tis impossible that the Pictures of two Objects, variously
+distant, can be perfectly painted, or made on the same _Retina_ or bottom
+of the eye not altered, as will be very evident to any one that shall
+attentively consider the nature of refraction. Now, whether this alteration
+may be in the Figure of the _Cornea_, in the motion of access or recess of
+the _Retina_ towards the _Cornea_, or in the alteration of a crustaline
+humour, if such there be, I pretend not to determine; though I think we
+need not doubt, but that there may be as much curiosity of contrivance and
+structure in every one of these Pearls, as in the eye of a Whale or
+Elephant, and the almighty's _Fiat_ could as easily cause the existence of
+the one as the other; and as one day and a thousand years are the same with
+him, so may one eye and ten thousand.
+
+This we may be sure of, that the filaments or sensative parts of the
+_Retina_ must be most exceedingly curious and minute, since the whole
+Picture it self is such; what must needs the component parts be of that
+_Retina_, which distinguishes the part of an object's Picture that must be
+many millions of millions less then that in a man's eye? And how exceeding
+curious and subtile must the component parts of the _medium_ that conveys
+light be, when we find the instrument made for its reception or refraction
+to be so exceedingly small? we may, I think, from this speculation be
+sufficiently discouraged from hoping to discover by any optick or other
+instrument the determinate bulk of the parts of the _medium_ that conveys
+the pulse of light, since we find that there is not less accurateness shewn
+in the Figure and polish of those exceedingly minute lenticular surfaces,
+then in those more large and conspicuous surfaces of our own eyes. And yet
+can I not doubt, but that there is a determinate bulk of those parts, since
+I find them unable to enter between the parts of Mercury, which being in
+motion, must necessarily have pores, as I shall elsewhere shew, and here
+pass by, as being a digression.
+
+As concerning the horns FF, the feelers or smellers, GG, the _Probascis_
+HH, and I, the hairs and brisles, KK, I shall indeavour to describe in the
+42. _Observation_.
+
+       *       *       *       *       *
+
+
+Observ. XL. _Of the Teeth of a _Snail_._
+
+I have little more to add of the Teeth of a Snail, besides the Picture of
+it, which is represented in the first _Figure_ of the 25. _Scheme_, save
+that his bended body, ABCDEF, which seem'd fashioned very much like a row
+of small teeth, orderly plac'd in the Gums, and looks as if it were divided
+into several smaller and greater black teeth, was nothing but one small
+bended hard bone, which was plac'd in the upper jaw of the mouth of a
+House-Snail, with which I observ'd this very Snail to feed on the leaves of
+a Rose-tree, and to bite out pretty large and half round bits, not unlike
+the Figure of a (C) nor very much differing from it in bigness, the upper
+part ABCD of this bone, I found to be much whiter, and to grow out of the
+upper chap of the Snail, GGG, and not to be any thing neer so much creas'd
+as the lower and blacker part of it HIIHKKH which was exactly shap'd like
+teeth, the bone growing thinner, or tapering to an edge towards KKK. It
+seem'd to have nine teeth, or prominent parts IK, IK, IF, &c. which were
+join'd together by the thinner interpos'd parts of the bone. The Animal to
+which these teeth belong, is a very _anomalous_ creature, and seems of a
+kind quite distinct from any other terrestrial Animal or Insect, the
+Anatomy whereof exceedingly differing from what has been hitherto given of
+it I should have inserted, but that it will be more proper in another
+place. I have never met with any kind of Animal whose teeth are all join'd
+in one, save onely that I lately observ'd, that all the teeth of a
+Rhinocerot, which grow on either side of its mouth, are join'd into one
+large bone, the weight of one of which I found to be neer eleven pound
+_Haverdupois_. So that it seems one of the biggest sort of terrestrial
+Animals, as well as one of the smallest, has his teeth thus shap'd.
+
+       *       *       *       *       *
+
+
+Observ. XLI. _Of the Eggs of _Silk-worms_, and other Insects._
+
+The Eggs of Silk-worms (one of which I have describ'd in the second
+_Figure_ of 25. _Scheme_) afford a pretty Object for a _Microscope_ that
+magnifies very much, especially if it be bright weather, and the light of a
+window be cast or collected on it by a deep _Convex-glass_, or Water-ball.
+For then the whole surface of the Shell may be perceiv'd all cover'd over
+with exceeding small pits or cavities with interposed edges, almost in the
+manner of the surface of a Poppy-seed, but that these holes are not an
+hundredth part scarce of their bigness; the Shell, when the young ones were
+hatch'd (which I found an easie thing to do, if the Eggs were kept in a
+warm place) appear'd no thicker in proportion to its bulk, then that of an
+Hen's or Goos's Egg is to its bulk, and all the Shell appear'd very white
+(which seem'd to proceed from its transparency) whence all those pittings
+did almost vanish, so that they could not, without much difficulty, be
+discern'd, the inside of the Shell seem'd to be lin'd also with a kind of
+thin film, not unlike (keeping the proportion to its Shell) that with which
+the shell of an Hen-egg is lin'd; and the shell it self seem'd like common
+Egg-shells; very brittle, and crack'd. In divers other of these Eggs I
+could plainly enough, through the shell, perceive the small Insect lie
+coyled round the edges of the shell. The shape of the Egg it self, the
+Figure pretty well represents (though by default of the Graver it does not
+appear so rounded, and lying above the Paper, as it were, as it ought to
+do) that is, it was for the most part pretty oval end-ways, somewhat like
+an Egg, but the other way it was a little flatted on two opposite sides.
+Divers of these Eggs, as is common to most others, I found to be barren, or
+addle, for they never afforded any young ones. And those I usually found
+much whiter then the other that were prolifick. The Eggs of other kinds of
+Oviparous Insects I have found to be perfectly round every way, like so
+many Globules, of this sort I have observ'd some sorts of Spiders Eggs; and
+chancing the last Summer to inclose a very large and curiously painted
+Butterfly in a Box, intending to examine its gaudery with my _Microscope_,
+I found within a day or two after I inclos'd her, almost all the inner
+surface of the Box cover'd over with an infinite of exactly round Eggs,
+which were stuck very fast to the sides of it, and in so exactly regular
+and close an order, that made me call to mind my _Hypothesis_, which I had
+formerly thought on for the making out of all the regular Figures of Salt,
+which I have elsewhere hinted; for here I found all of them rang'd into a
+most exact _triagonal_ order, much after the manner as the _Hemispheres_
+are place on the eye of a Fly; all which Eggs I found after a little time
+to be hatch'd, and out of them to come a multitude of small Worms, very
+much resembling young Silk-worms, leaving all their thin hollow shells
+behind them, sticking on the Box in their _triagonal_ posture; these I
+found with the _Microscope_ to have much such a substance as the Silk-worms
+Eggs, but could not perceive them pitted. And indeed, there is as great a
+variety in the shape of the Eggs of Oviparous Insects as among those of
+Birds.
+
+Of these Eggs, a large and lusty Fly will at one time lay neer four or five
+hundred, so that the increase of these kind of Insects must needs be very
+prodigious, were they not prey'd on by multitudes of Birds, and destroy'd
+by Frosts and Rains; and hence 'tis those hotter Climates between the
+_Tropicks_ are infested with such multitudes of Locusts, and such other
+Vermine.
+
+       *       *       *       *       *
+
+
+Observ. XLII. _Of a blue _Fly_._
+
+This kind of Fly, whereof a _Microscopical_ Picture is delineated in the
+first _Figure_ of the 26. _Scheme_, is a very beautifull creature, and has
+many things about it very notable; divers of which I have already partly
+describ'd, namely, the feet, wings, eyes, and head, in the preceding
+Observations.
+
+And though the head before describ'd be that of a grey _Drone-Fly_, yet for
+the main it is very agreeable to this. The things wherein they differ most,
+will be easily enough found by the following particulars:
+
+First, the clusters of eyes of this Fly, are very much smaller then those
+of the _Dron-Fly_, in proportion to the head.
+
+And next, all the eyes of each cluster seem'd much of the same bigness one
+with another, not differing as the other, but rang'd in the same
+_triagonal_ order.
+
+Thirdly, between these two clusters, there was a scaly prominent _front_ B,
+which was arm'd and adorn'd with large tapering sharp black brisles, which
+growing out in rows on either side, were so bent toward each other neer the
+top, as to make a kind of arched arbour of Brisles, which almost cover'd
+the former _front_.
+
+Fourthly, at the end of this Arch, about the middle of the face, on a
+prominent part C, grew two small oblong bodies, DD, which through a
+_Microscope_ look'd not unlike the Pendants in Lillies, these seem'd to be
+jointed on to two small parts at C, each of which seem'd again jointed into
+the front.
+
+Fifthly, out of the upper part and outsides of these horns (as I may call
+them, from the Figure they are of, in the 24. _Scheme_, where they are
+marked with FF) there grows a single feather, or brushy Brisle, EE,
+somewhat of the same kind with the tufts of a Gnat, which I have before
+described.
+
+What the use of these kind of horned and tufted bodies should be, I cannot
+well imagine, unless they serve for smelling or hearing, though how they
+are adapted for either, it seems very difficult to describe: they are in
+almost every several kind of Flies of so various a shape; though certainly
+they are some very essential part of the head, and have some very notable
+office assign'd them by Nature, since in all Insects they are to be found
+in one or other form.
+
+Sixthly, at the under part of the face FF, were several of the former sort
+of bended Brisles, and below all, the mouth, out of the middle of which,
+grew the _proboscis_ GHI, which, by means of several joints, whereof it
+seem'd to consist, the Fly was able to move to and fro, and thrust it in
+and out as it pleas'd; the end of this hollow body (which was all over
+cover'd with small short hairs or brisles) was, as 'twere, bent at H, and
+the outer or formost side of the bended part HI, slit, as it were, into two
+chaps, HI, HI, all the outside of which where cover'd with hairs, and
+pretty large brisles; these he could, like two chaps, very readily open and
+shut, and when he seem'd to suck any thing from the surface of a body, he
+would spread abroad those chaps, and apply the hollow part of them very
+close to it.
+
+From either side of the _Proboscis_, within the mouth, grew two other small
+horns, or fingers, KK, which were hairy, but small in this Figure; but of
+another shape, and bigger in proportion, in the 24. _Scheme_, where they
+are marked with GG, which two indeed seem'd a kind of smellers, but whether
+so or not, I cannot positively determine.
+
+The _Thorax_ or middle part of this Fly, was cas'd, both above and beneath,
+with a very firm crust of armour, the upper part more round, and covered
+over with long _conical_ brisles, all whose ends pointed backwards; out of
+the hinder and under part of this grew out in a cluster six leggs, three of
+which are apparent in the Figure, the other three were hid by the body
+plac'd in that posture. The leggs were all much of the same make, being all
+of them cover'd with a strong hairy scale or shel, just like the legs of a
+Crabb or Lobster, and the contrivance of the joints seem'd much the same,
+each legg seem'd made up of eight parts, 1, 2, 3, 4, 5, 6, 7, 8, to the
+eighth or last of which, grew the soles and claws, described before in the
+38. _Observation_.
+
+Out of the upper part of this trunck grew the two wings, which I mention'd
+in the 38. _Observation_, consisting of a film, extended on certain small
+stiff wires or bones: these in a blue Fly, were much longer then the body,
+but in other kind of Flies they are of very differing proportions to the
+body. These films, in many Flies, were so thin, that, like several other
+plated bodies (mention'd in the ninth _Observation_) they afforded all
+varieties of fantastical or transient colours (the reason of which I have
+here endeavoured to explain) they seem'd to receive their nourishment from
+the stalks or wires, which seem'd to be hollow, and neer the upper part of
+the wing LL several of them seem'd jointed, the shape of which will
+sufficiently appear by the black lines in the second Figure of the 26.
+_Scheme_, which is a delineation of one of those wings expanded directly to
+the eyes.
+
+All the hinder part of its body is cover'd with a most curious blue shining
+armour, looking exactly like a polish'd piece of steel brought to that blue
+colour by annealing, all which armour is very thick bestuck with abundance
+of tapering brisles, such as grow on its back, as is visible enough by the
+Figure.
+
+Nor was the inside of this creature less beautifull then its outside, for
+cutting off a part of the belly, and then viewing it, to see if I could
+discover any Vessels, such as are to be found in a greater Animals, and
+even in Snails exceeding manifestly, I found, much beyond my expectation,
+that there were abundance of branchings of Milk-white vessels, no less
+curious then the branchings of veins and arteries in bigger terrestrial
+Animals, in one of which, I found two notable branches, joining their two
+main stocks, as it were, into one common _ductus_; now, to what veins or
+arteries these Vessells were _analogus_, whether to the _vena porta_, or
+the _meseraick vessells_, or the like, or indeed, whether they were veins
+and arteries, or _vasa lactea_, properly so called, I am not hitherto able
+to determine, having not yet made sufficient enquiry; but in all
+particulars, there seems not to be any thing less of curious contrivance in
+these Insects, then in those larger terrestrial Animals, for I had never
+seen any more curious branchings of Vessels, then those I observ'd in two
+or three of these Flies thus opened.
+
+It is a creature active and nimble, so as there are very few creatures like
+it, whether bigger or smaller, in so much, that it will scape and avoid a
+small body, though coming on it exceeding swiftly, and if it sees any thing
+approaching it, which it fears, it presently squats down, as it were, that
+it may be the more ready for its rise.
+
+Nor is it less hardy in the Winter, then active in the Summer, induring all
+the Frosts, and surviving till the next Summer, notwithstanding the bitter
+cold of our Climate; nay, this creature will indure to be frozen, and yet
+not be destroy'd, for I have taken one of them out of the Snow whereon it
+has been frozen almost white, with the Ice about it, and yet by thawing it
+gently by the warmth of a fire, it has quickly reviv'd and flown about.
+
+This kind of Fly seems by the steams or taste of fermenting and putrifying
+meat (which it often kisses, as 'twere, with its _proboscis_ as it trips
+over it) to be stimulated or excited to eject its Eggs or Seed on it,
+perhaps, from the same reason as Dogs, Cats, and many other brute creatures
+are excited to their particular lusts, by the smell of their females, when
+by Nature prepared for generation; the males seeming by those kind of
+smells, or other incitations, to be as much necessitated thereto, as _Aqua
+Regis_ strongly impregnated with a solution of Gold, is forced to
+precipitate it by the affusion of spirit of _Urine_, or a solution of
+_Salt_ of _Tartar_.
+
+One of these put in spirit of _Wine_, was very quickly seemingly kill'd,
+and both its eys and mouth began to look very red, but upon the taking of
+it out, and suffering it to lie three or four hours, and heating it with
+the Sun beams cast through a Burning-glass, it again reviv'd, seeming, as
+it were, to have been all the intermediate time, but dead drunk, and after
+certain hours to grow fresh again and sober.
+
+       *       *       *       *       *
+
+
+Observ. XLIII. _Of the _Water-Insect_ or _Gnat_._
+
+This little creature, described in the first _Figure_ of the 27. _Scheme_,
+was a small scaled or crusted Animal, which I have often observ'd to be
+generated in Rain-water; I have also observ'd it both in Pond and
+River-water. It is suppos'd by some, to deduce its first original from the
+putrifaction of Rain-water, in which, if it have stood any time open to the
+air, you shall seldom miss, all the Summer long, of store of them frisking
+too and fro.
+
+'Tis a creature, wholly differing in shape from any I ever observ'd; nor is
+its motion less strange: It has a very large head, in proportion to its
+body, all covered with a shell, like other _testaceous_ Animals, but it
+differs in this, that it has, up and down several parts of it, several
+tufts of hairs, or brisles, plac'd in the order express'd in the Figure; It
+has two horns, which seem'd almost like the horns of an Oxe, inverted, and,
+as neer as I could guess, were hollow, with tufts of brisles, likewise at
+the top; these horns they could move easily this or that way, and might,
+perchance, be their nostrils. It has a pretty large mouth, which seem'd
+contriv'd much like those of Crabs and Lobsters, by which, I have often
+observ'd them to feed on water, or some imperceptible nutritive substance
+in it.
+
+I could perceive, through the transparent shell, while the Animal surviv'd,
+several motions in the head, thorax, and belly, very distinctly, of
+differing kinds which I may, perhaps, elsewhere endeavour more accurately
+to examine, and to shew of how great benefit the use of a _Microscope_ may
+be for the discovery of Nature's course in the operations perform'd in
+Animal bodies, by which we have the opportunity of observing her through
+these delicate and pellucid teguments of the bodies of Insects acting
+according to her usual course and way, undisturbed, whereas, when we
+endeavour to pry into her secrets by breaking open the doors upon her, and
+dissecting and mangling creatures whil'st there is life yet within them, we
+find her indeed at work, but put into such disorder by the violence
+offer'd, as it may easily be imagin'd, how differing a thing we should
+find, if we could, as we can with a _Microscope_ in these smaller
+creatures, quietly peep in at the windows, without frighting her out of her
+usual byas.
+
+The form of the whole creature, as it appear'd in the _Microscope_, may,
+without troubling you with more descriptions, be plainly enough perceiv'd
+by the _Scheme_, the hinder part or belly consisting of eight several
+jointed parts, namely, ABCDEFGH, of the first _Figure_, from the midst of
+each of which, on either side issued out three or four small brisles or
+hairs, I, I, I, I, I, the tail was divided into two parts of very differing
+make; one of them, namely, K, having many tufts of hair or brisles, which
+seem'd to serve both for the finns and tail, for the Oars and Ruder of this
+little creature, wherewith it was able, by frisking and bending its body
+nimbly to and fro, to move himself any whither, and to skull and steer
+himself as he pleas'd, the other part, L, seem'd to be, as 'twere, the
+ninth division of his belly, and had many single brisles on either side.
+From the end V, of which, through the whole belly, there was a kind of Gut
+of a darker colour, MMM, wherein, by certain _Peristaltick_ motions there
+was a kind of black substance mov'd upwards and downwards through it from
+the orbicular part of it, N, (which seem'd the _Ventricle_, or stomach) to
+the tail V, and so back again, which _peristaltick_ motion I have observ'd
+also in a Louse, a Gnat, and several other kinds of transparent body'd
+Flies. The _Thorax_ or chest of this creature OOOO, was thick and short,
+and pretty transparent, for through it I could see the white heart (which
+is the colour also of the bloud in these, and most other Insects) to beat,
+and several other kind of motions. It was bestuck and adorn'd up and down
+with several tufts of brisles, such as are pointed out by P, P, P, P, the
+head Q was likewise bestuck with several of those tufts, SSS; it was broad
+and short, had two black eyes, TT, which I could not perceive at all
+pearl'd, as they afterwards appear'd, and two small horns, RR, such as I
+formerly describ'd.
+
+Both its motion and rest is very strange, and pleasant, and differing from
+those of most other creatures I have observ'd; for, where it ceases from
+moving its body, the tail of it seeming much lighter then the rest of its
+body, and a little lighter then the water it swims in, presently boys it up
+to the top of the water, where it hangs suspended with the head always
+downward; and like our _Antipodes_, if they do by a frisk get below that
+superficies, they presently ascend again unto it, if they cease moving,
+until they tread, as it were, under that superficies with their tails; the
+hanging of these in this posture, put me in mind of a certain creature I
+have seen in _London_, that was brought out of _America_, which would very
+firmly suspend it self by the tail, with the head downwards, and was said
+to keep in that posture, with her young ones in her false belly, which is a
+Purse, provided by Nature for the production, nutrition, and preservation
+of her young ones, which is described by _Piso_ in the 24. Chapter of the
+fifth Book of his Natural History of _Brasil_.
+
+The motion of it was with the tail forwards, drawing its self backwards, by
+the striking to and fro of that tuft which grew out of one of the stumps of
+its tail. It had another motion, which was more sutable to that of other
+creatures, and that is, with the head forward; for by the moving of his
+chaps (if I may so call the parts of his mouth) it was able to move it self
+downwards very gently towards the bottom, and did, as 'twere, eat up its
+way through the water.
+
+But that which was most observable in this creature, was, its Metamorphosis
+or change; for having kept several of these Animals in a Glass of
+Rain-water, in which they were produc'd, I found, after about a fortnight
+or three weeks keeping, that several of them flew away in Gnats, leaving
+their husks behind them in the water floating under the surface, the place
+where these Animals were wont to reside, whil'st they were inhabitants of
+the water: this made me more diligently to watch them, to see if I could
+find them at the time of their transformation; and not long after, I
+observ'd several of them to be changed into an unusual shape, wholly
+differing from that they were of before, their head and body being grown
+much bigger and deeper, but not broader, and their belly, or hinder part
+smaller, and coyl'd, about this great body much of the fashion represented
+by the prick'd line in the second _Figure_ of the 27. _Scheme_, the head
+and horns now swam uppermost, and the whole bulk of the body seem'd to be
+grown much lighter; for when by my frighting of it, it would by frisking
+out of its tail (in the manner express'd in the Figure by BC) sink it self
+below the surface towards the bottom; the body would more swiftly
+re-ascend, then when it was in its former shape.
+
+I still marked its progress from time to time, and found its body still to
+grow bigger and bigger, Nature, as it were, fitting and accoutring it for
+the lighter Element, of which it was now going to be an inhabitant; for, by
+observing one of these with my _Microscope_, I found the eyes of it to be
+altogether differing from what they seem'd before, appearing now all over
+pearl'd or knobb'd, like the eyes of Gnats, as is visible in the second
+_Figure_ by A. At length, I saw part of this creature to swim above, and
+part beneath the surface of the water, below which though it would quickly
+plunge it self if I by any means frighted it, and presently re-ascend into
+its former posture; after a little longer expectation, I found that the
+head and body of a Gnat, began to appear and stand cleer above the surface,
+and by degrees it drew out its leggs, first the two formost, then the
+other, at length its whole body perfect and entire appear'd out of the husk
+(which it left in the water) standing on its leggs upon the top of the
+water, and by degrees it began to move, and after flew about the Glass a
+perfect Gnat.
+
+I have been the more particular, and large in the relation of the
+transformation of divers of these little Animals which I observ'd, because
+I have not found that any Authour has observ'd the like, and because the
+thing it self is so strange and heterogeneous from the usual progress of
+other Animals, that I judge it may not onely be pleasant, but very usefull
+and necessary towards the compleating of Natural History.
+
+There is indeed in _Piso_, a very odd History, which this relation may make
+the more probable; and that is in the 2. Chapter of the 4. Book of his
+Natural History of _Brasil_, where he says, _Porro præter tot documenta
+fertilitatis circa vegetabilia & sensitiva marina telluris æmula, accidit &
+illud, quod paucis à Paranambucensi milliaribus, piscatoris uncum citra
+intentionem contingat infigi vadis petrosis, & loco piscis spongia,
+coralla, aliasque arbusculas marinas capi. Inter hæc inusitatæ formæ prodit
+spongiosa arbuscula sesquipedis longitudinis, brevioribus radicibus,
+lapideis nitens vadis, & rupibus infixa, erigiturque in corpus spongiosum
+molle oblongum rotundum turbinatum: intus miris cancellis & alveis
+fabricatum, extus autem tenaci glutine instar Apum propolis undique
+vestitum, ostio satis patulo & profundo in summitate relicto, sicut ex
+altera iconum probe depicta videre licet _(see the third and fourth
+_Figures_ of the 27. _Scheme_.)_ Ita ut Apiarium marinum vere dixeris;
+primo enim intuitu è Mare ad Terram delatum, vermiculis scatebat cæruleis
+parvis, qui mox à calore solis in Muscas, vel Apes potius, easq; exiguas &
+nigras transformebantur, circumvolantesque evanescebant, ita ut de eorum
+mellificatione nihil certi conspici datum fuerit, cum tamen cærosa materia
+propolis Apumque cellæ manifeste apparerent, atque ipsa mellis qualiscunque
+substantia proculdubio urinatoribus patebit, ubi curiosius inquisiverint
+hæc apiaria, eaque in natali solo & salo diversis temporibus penitius
+lustrarint_.
+
+Which History contains things sufficiently strange to be consider'd, as
+whether the husk were a Plant, growing at the bottom of the Sea before, of
+it self, out of whose putrifaction might be generated these strange kind of
+Magots; or whether the seed of certain Bees, sinking to the bottom, might
+there naturally form it self that vegetable hive, and take root; or,
+whether it might not be placed there by some diving Fly; or, whether it
+might not be some peculiar propriety of that Plant, whereby it might ripen
+or form its vegetable juice into an Animal substance; or, whether it may
+not be of the nature of a Sponge, or rather a Sponge of the nature of this,
+according to some of those relations and conjectures I formerly made of
+that body, is a matter very difficult to be determined. But indeed, in this
+description, the Excellent _Piso_ has not been sufficiently particular in
+the setting down the whole process, as it were to be wish'd: There are
+indeed very odd progresses in the production of several kinds of Insects,
+which are not less instructive then pleasant, several of which, the
+diligent _Goedartius_ has carefully observ'd and recorded, but among all
+his Observations, he has none like this, though that of the _Hemerobius_ be
+somewhat of this kind, which is added as an Appendix by _Johannes Mey_.
+
+I have, for my own particular, besides several of those mention'd by him,
+observ'd divers other circumstances, perhaps, not much taken notice of,
+though very common, which do indeed afford us a very _coercive_ argument to
+admire the goodness and providence of the infinitely wise Creator in his
+most excellent contrivances and dispensations. I have observ'd, at several
+times of the Summer, that many of the leaves of divers Plants have been
+spotted, or, as it were scabbed, and looking on the undersides of those of
+them that have been but a litte irregular, I have perceiv'd them to be
+sprinkled with divers sorts of little Eggs, which letting alone, I have
+found by degrees to grow bigger, and become little Worms with leggs, but
+still to keep their former places, and those places of the leaves, of their
+own accords, to be grown very protuberant upwards, and very hollow, and
+arched underneath, whereby those young creatures are, as it were, shelter'd
+and housed from external injury; divers leaves I have observ'd to grow and
+swell so farr, as at length perfectly to inclose the Animal, which, by
+other observations I have made, I ghess to contain it, and become, as it
+were a womb to it, so long, till it be fit and prepar'd to be translated
+into another state, at what time, like (what they say of) Vipers, they gnaw
+their way through the womb that bred them; divers of these kinds I have met
+with upon Goosberry leaves, Rose-tree leaves, Willow leaves, and many other
+kinds.
+
+There are often to be found upon Rose-trees and Brier bushes, little red
+tufts, which are certain knobs or excrescencies, growing out from the Rind,
+or barks of those kinds of Plants, they are cover'd with strange kinds of
+threads or red hairs, which feel very soft, and look not unpleasantly. In
+most of these, if it has no hole in it, you shall find certain little
+Worms, which I suppose to be the causes of their production; for when that
+Worm has eat its way through, they, having performed what they were
+design'd by Nature to do, by degrees die and wither away.
+
+Now, the manner of their production, I suppose to be thus, that the Alwise
+Creator has as well implanted in every creature a faculty of knowing what
+place is convenient for the hatching, nutrition, and preservation of their
+Eggs and of-springs whereby they are stimulated and directed to convenient
+places, which becom, as 'twere the wombs that perform those offices: As he
+has also suited and adapted a property to those places wherby they grow and
+inclose those seeds, and having inclosed them, provide a convenient
+nourishment for them, but as soon as they have done the office of a womb,
+they die and wither.
+
+The progress of inclosure I have often observ'd in leaves, which in those
+places where those seeds have been cast, have by degrees swell'd and
+inclos'd them, so perfectly round, as not to leave any perceptible passage
+out.
+
+From this same cause, I suppose that Galls, Oak-apples, and several other
+productions of that kind, upon the branches and leaves of Trees, have their
+original, for if you open any of them, when almost ripe, you shall find a
+little Worm in them. Thus, if you open never so many dry Galls, you shall
+find either a hole whereby the Worm has eat its passage out, or if you find
+no passage, you may, by breaking or cutting the Gall, find in the middle of
+it a small cavity, and in it a small body, which does plainly enough yet
+retain a shape, to manifest it once to have been a Worm, though it dy'd by
+a too early reparation from the Oak on which it grew, its navel-string, as
+'twere, being broken off from the leaf or branch by which the Globular body
+that invelop'd it, received its nourishment from the Oak.
+
+And indeed, if we consider the great care of the Creator in the
+dispensations of his providences for the propagation and increase of the
+race, not onely of all kind of Animals, but even of Vegetables, we cannot
+chuse but admire and adore him for his Excellencies, but we shall leave off
+to admire the creature, or to wonder at the strange kind of acting in
+several Animals, which seem to favour so much of reason; it seeming to me
+most manifest, that those are but actings according to their structures,
+and such operations as such bodies, so compos'd, must necessarily, when
+there are such and such circumstances concurring, perform: thus, when we
+find Flies swarming, about any piece of flesh that does begin a little to
+ferment; Butterflies about Colworts, and several other leaves, which will
+serve to hatch and nourish their young; Gnats, and several other Flies
+about the Waters, and marishy places, or any other creatures, seeking and
+placing their Seeds in convenient repositories, we may, if we attentively
+consider and examine it, find that there are circumstances sufficient, upon
+the supposals of the excellent contrivance of their machine, to excite and
+force them to act after such or such a manner; those steams that rise from
+these several places may, perhaps, set several parts of these little
+Animals at work, even as in the contrivance of killing a Fox or Wolf with a
+Gun, the moving of a string, is the death of the Animal; for the Beast, by
+moving the flesh that is laid to entrap him, pulls the string which moves
+the trigger, and that lets go the Cock which on the steel strikes certain
+sparks of fire which kindle the powder in the pann, and that presently
+flies into the barrel, where the powder catching fire rarifies and drives
+out the bullet which kills the Animal; in all which actions, there is
+nothing of intention or ratiocination to be ascrib'd either to the Animal
+or Engine, but all to the ingeniousness of the contriver.
+
+But to return to the more immediate consideration of our Gnat: We have in
+it an Instance, not usual or common, of a very strange _amphibious_
+creature, that being a creature that inhabits the Air, does yet produce a
+creature, that for some time lives in the water as a Fish, though afterward
+(which is as strange) it becomes an inhabitant of the Air, like its Sire,
+in the form of a Fly. And this, methinks, does prompt me to propose certain
+conjectures, as Queries, having not yet had sufficient opportunity and
+leisure to answer them my self from my own Experiments or Observations.
+
+And the first is, Whether all those things that we suppose to be bred from
+corruption and putrifaction, may not be rationally suppos'd to have their
+origination as natural as these Gnats, who, 'tis very probable, were first
+dropt into this Water, in the form of Eggs. Those Seeds or Eggs must
+certainly be very small, which so small a creature as a Gnat yields, and
+therefore, we need not wonder that we find not the Eggs themselves, some of
+the younger of them, which I have observ'd, having not exceeded a tenth
+part of the bulk they have afterwards come to; and next, I have observed
+some of those little ones which must have been generated after the Water
+was inclosed in the Bottle, and therefore most probably from Eggs, whereas
+those creatures have been suppos'd to be bred of the corruption of the
+Water, there being not formerly known any probable way how they should be
+generated.
+
+A second is, whether these Eggs are immediately dropt into the Water by the
+Gnats themselves, or, mediately, are brought down by the falling rain; for
+it seems not very improbable, but that those small seeds of Gnats may
+(being, perhaps, of so light a nature, and having so great a proportion of
+surface to so small a bulk of body) be ejected into the Air, and so,
+perhaps, carried for a good while too and fro in it, till by the drops of
+Rain it be wash'd out of it.
+
+A third is, whether multitudes of those other little creatures that are
+found to inhabit the Water for some time, do not, at certain times, take
+wing and fly into the Air, others dive and hide themselves in the Earth,
+and so contribute to the increase both of the one and the other Element.
+
+       *       *       *       *       *
+
+_Postscript._
+
+A good while since the writing of this Description, I was presented by
+Doctor _Peter Ball_, an ingenious Member of the _Royal Society_, with a
+little Paper of Nuts, which he told me was sent him from a Brother of his
+out of the Countrey, from _Mamhead_ in _Devonshire_, some of them were
+loose, having been, as I suppose, broken off, others were still growing
+fast on upon the sides of a stick, which seem'd by the bark, pliableness of
+it, and by certain strings that grew out of it, to be some piece of the
+root of a Tree; they were all of them dry'd, and a little shrivell'd,
+others more round, of a brown colour; their shape was much like a Figg, but
+very much smaller, some being about the bigness of a Bay-berry, others, and
+the biggest, of a Hazel-Nut. Some of these that had no hole in them, I
+carefully opened with my Knife, and found in them a good large round white
+Maggot, almost as bigg as a small Pea, which seem'd shap'd like other
+Maggots, but shorter. I could not find them to move, though I ghess'd them
+to be alive, because upon pricking them with a Pinn, there would issue out
+a great deal of white _mucous_ matter, which seem'd to be from a voluntary
+contraction of their skin; their husk or matrix consisted of three Coats,
+like the barks of Trees, the outermost being more rough and spongie, and
+the thickest, the middlemost more close, hard, white, and thin, the
+innermost very thin, seeming almost like the skin within an Egg's shell.
+The two outermost had root in the branch or stick, but the innermost had no
+stem or process, but was onely a skin that cover'd the cavity of the Nut.
+All the Nuts that had no holes eaten in them, I found to contain these
+Maggots, but all that had holes, I found empty, the Maggots, it seems,
+having eaten their way through, taken wings and flown away, as this
+following account (which I receiv'd in writing from the same person, as it
+was sent him by his Brother) manifests. _In a moorish black Peaty mould,
+with some small veins of whitish yellow Sands, upon occasion of digging a
+hole two or three foot deep, at the head of a Pond or Pool, to set a Tree
+in, at that depth, were found, about the end of _October 1663._ in those
+very veins of Sand, those Buttons or Nuts, sticking to a little loose
+stick, that is, not belonging to any live Tree, and some of them also free
+by themselves._
+
+_Four or five of which being then open'd, some were found to contain live
+Insects come to perfection, most like to flying _Ants_, if not the same; in
+others, Insects, yet imperfect, having but the head and wings form'd, the
+rest remaining a soft white pulpy substance._
+
+Now, as this furnishes us with one odd History more, very agreeable to what
+I before hinted, so I doubt not, but were men diligent observers, they
+might meet with multitudes of the same kind, both in the Earth and in the
+Water, and in the Air, on Trees, Plants, and other Vegetables, all places
+and things being, as it were, _animarum plena_. And I have often, with
+wonder and pleasure, in the Spring and Summer-time, look'd close to, and
+diligently on, common Garden mould, and in a very small parcel of it, found
+such multitudes and diversities of little _reptiles_, some in husks, others
+onely creepers, many wing'd, and ready for the Air; divers husks or
+habitations left behind empty. Now, if the Earth of our cold Climate be so
+fertile of animate bodies, what may we think of the fat Earth of hotter
+Climates? Certainly, the Sun may there, by its activity, cause as great a
+parcel of Earth to fly on wings in the Air, as it does of Water in steams
+and vapours. And what swarms must we suppose to be sent out of those
+plentifull inundations of water which are poured down by the sluces of Rain
+in such vast quantities? So that we need not much wonder at those
+innumerable clouds of Locusts with which _Africa_, and other hot countries
+are so pestred, since in those places are found all the convenient causes
+of their production, namely, genitors, or Parents, concurrent receptacles
+or matrixes, and a sufficient degree of natural heat and moisture.
+
+I was going to annex a little draught of the Figure of those Nuts sent out
+of _Devonshire_, but chancing to examine Mr. _Parkinson_'s Herbal for
+something else, and particularly about Galls and Oak-apples, I found among
+no less then 24. several kinds of excrescencies of the Oak, which I doubt
+not, but upon examination, will be all found to be the _matrixes_ of so
+many several kinds of Insects; I having observ'd many of them my self to be
+so, among 24. several kinds, I say, I found one described and Figur'd
+directly like that which I had by me, the _Scheme_ is there to be seen, the
+description, because but short, I have here adjoin'd _Theatri Botanici
+trib. 16. Chap. 2. There groweth at the roots of old Oaks in the
+Spring-time, and semetimes also in the very heat of Summer, a peculiar kind
+of Mushrom or Excrescence, call'd _Uva Quercina_, swelling out of the
+Earth, many growing one close unto another, of the fashion of a Grape, and
+therefore took the name, the _Oak-Grape_, and is of a Purplish colour on
+the outside, and white within like Milk, and in the end of Summer becometh
+hard and woody._ Whether this be the very same kind, I cannot affirm, but
+both the Picture and Description come very neer to that I have, but that he
+seems not to take notice of the hollowness or Worm, for which 'tis most
+observable. And therefore 'tis very likely, if men did but take notice,
+they might find very many differing Species of these Nuts, _Ovaries_, or
+_Matrixes_, and all of them to have much the same designation and office.
+And I have very lately found several kinds of Excrescencies on Trees and
+Shrubs, which having endured the Winter, upon opening them, I found most of
+them to contain little Worms, but dead, those things that contain'd them
+being wither'd and dry.
+
+       *       *       *       *       *
+
+
+Observ. XLIV. _Of the tufted or Brush-horn'd _Gnat_._
+
+This little creature was one of those multitudes that fill our _English_
+air all the time that warm weather lasts, and is exactly of the shape of
+that I observ'd to be generated and hatch'd out of those little Insects
+that wriggle up and down in Rain-water. But, though many were of this form,
+yet I observ'd others to be of quite other kinds; nor were all of this or
+the other kind generated out of Water Insects; for whereas I observ'd that
+those that proceeded from those Insects were at their full growth, I have
+also found multitudes of the same shape, but much smaller and tenderer
+seeming to be very young ones, creep up and down upon the leaves of Trees,
+and flying up and down in small clusters, in places very remote from water;
+and this Spring, I observ'd one day, when the Wind was very calm, and the
+afternoon very fair, and pretty warm, though it had for a long time been
+very cold weather, and the wind continued still in the East, several small
+swarms of them playing to and fro in little clouds in the Sun, each of
+which were not a tenth part of the bigness of one of these I here have
+delineated, though very much of the same shape, which makes me ghess, that
+each of these swarms might be the of-spring of one onely Gnat, which had
+been hoorded up in some safe repository all this Winter by some provident
+Parent, and were now, by the warmth of the Spring-air, hatch'd into little
+Flies.
+
+And indeed, so various, and seemingly irregular are the generations or
+productions of Insects, that he that shall carefully and diligently observe
+the several methods of Nature therein, will have infinitely cause further
+to admire the wisdom and providence of the Creator; for not onely the same
+kind of creature may be produc'd from several kinds of ways, but the very
+same creature may produce several kinds: For, as divers Watches may be made
+out of several materials, which may yet have all the same appearance, and
+move after the same manner, that is, shew the hour equally true, the one as
+the other, and out of the same kind of matter, like Watches, may be wrought
+differing ways; and, as one and the same Watch may, by being diversly
+agitated, or mov'd, by this or that agent, or after this or that manner,
+produce a quite contrary effect: So may it be with these most curious
+Engines of Insect's bodies; the All-wise God of Nature, may have so ordered
+and disposed the little _Automatons_, that when nourished, acted, or
+enlivened by this cause, they produce one kind of effect, or animate shape,
+when by another they act quite another way, and another Animal is produc'd.
+So may he so order several materials, as to make them, by several kinds of
+methods, produce similar _Automatons_.
+
+But to come to the Description of this Insect, as it appears through a
+_Microscope_, of which a representation is made in the 28. _Scheme_. Its
+head A, is exceeding small, in proportion to its body, consisting of two
+clusters of pearl'd eyes BB, on each side of its head, whose pearls or
+eye-balls are curiously rang'd like those of other Flies; between these, in
+the forehead of it, there are plac'd upon two small black balls, CC, two
+long jointed horns, tapering towards the top, much resembling the long
+horns of Lobsters, each of whose stems or quills, DD, were brisled or
+brushed with multitudes of small stiff hairs, issuing out every way from
+the several joints, like the strings or sproutings of the herb
+_Horse-tail_, which is oft observ'd to grow among Corn, and for the whole
+shape, it does very much resemble those _brushy Vegetables_; besides these,
+there are two other jointed and brisled horns, or feelers, EE, in the
+forepart of the head, and a _proboscis_, F, underneath, which in some Gnats
+are very long, streight hollow pipes, by which these creatures are able to
+drill and penetrate the skin, and thence, through those pipes suck so much
+bloud as to stuff their bellies so full till they be ready to burst.
+
+This small head, with its appurtenances, is fastned on by a short neck, G,
+to the middle of the _thorax_, which is large, and seems cased with a
+strong black shel, HIK, out of the under part of which, issue six long and
+slender legs, LLLLLL, shap'd just like the legs of Flies, but spun or drawn
+out longer and slenderer, which could not be express'd in the Figure,
+because of their great length; and from the upper part, two oblong, but
+slender transparent wings, MM, shaped somewhat like those of a Fly,
+underneath each of which, as I have observ'd also in divers sorts of Flies,
+and other kinds of Gnats, was placed a small body, N, much resembling a
+drop of some transparent glutinous substance, hardned or cool'd, as it was
+almost ready to fall, for it has a round knob at the end, which by degrees
+grows slenderer into a small stem, and neer the insertion under the wing,
+this stem again grows bigger; these little _Pendulums_, I may so call them,
+the litle creature vibrates to and fro very quick when it moves its wings,
+and I have sometimes observ'd it to move them also, whil'st the wing lay
+still, but always their motion seem'd to further the motion of the wing
+ready to follow; of what use they are, as to the moving of the wing, or
+otherwise, I have not now time to examine.
+
+Its belly was large, as it is usually in all Insects, and extended into
+nine lengths or partitions, each of which was cover'd with round armed
+rings or shells; six of which, OPQRST were transparent, and divers kinds of
+_Peristaltick_ motions might be very easily perceiv'd, whil'st the Animal
+was alive, but especially a small cleer white part V, seemed to beat like
+the heart of a larger Animal. The last three divisios, WXY, were cover'd
+with black and opacous shells. To conclude, take this creature altogether,
+and for beauty and curious contrivances, it may be compared with the
+largest Animal upon the Earth. Nor doth the Alwise Creator seem to have
+shewn less care and providence in the fabrick of it, then in those which
+seem most considerable.
+
+       *       *       *       *       *
+
+
+Observ. XLV. _Of the great Belly'd _Gnat_ or female _Gnat_._
+
+The second Gnat, delineated in the twenty ninth _Scheme_, is of a very
+differing shape from the former; but yet of this sort also, I found several
+of the Gnats, that were generated out of the Water Insect: the wings of
+this, were much larger then those of the other, and the belly much bigger,
+shorter and of an other shape; and, from several particulars, I ghest it to
+be the Female Gnat, and the former to be the Male.
+
+The _thorax_ of this, was much like that of the other, having a very strong
+and ridged back-piece, which went also on either side of its leggs; about
+the wings there were several joynted pieces of Armor, which seem'd
+curiously and conveniently contriv'd, for the promoting and strengthning
+the motion of the wings: its head was much differing from the other, being
+much bigger and neater shap'd, and the horns that grew out between his eyes
+on two little balls, were of a very differing shape from the tufts of the
+other Gnat, these having but a few knots or joynts, and each of those but a
+few, and those short and strong, brisles. The formost horns or feelers,
+were like those of the former Gnat.
+
+One of these Gnats I have suffer'd to pierce the skin of my hand, with its
+_proboscis_, and thence to draw out as much blood as to fill its belly as
+full as it could hold, making it appear very red and transparent; and this
+without any further pain, then whilst it was sinking in its _proboscis_, as
+it is also in the stinging of Fleas: a good argument, that these creatures
+do not wound the skin, and suck the blood out of enmity and revenge, but
+for meer necessity, and to satisfy their hunger. By what means this
+creature is able to suck, we shall shew in another place.
+
+       *       *       *       *       *
+
+
+Observ. XLVI. _Of the white featherwing'd _Moth_ or _Tinea Argentea_._
+
+This white long wing'd Moth, which is delineated in the 30. _Scheme_;
+afforded a lovely object both to the naked Eye, and through a _Microscope_:
+to the Eye it appear'd a small Milk white Fly with four white Wings, the
+two formost somewhat longer then the two hindermost, and the two shorter
+about half an Inch long, each of which four Wings seem'd to consist of two
+small long Feathers, very curiously tufted, or haired on each side, with
+purely white, and exceedingly fine and small Haires, proportion'd to the
+stalks or stems, out of which they grew, much like the tufts of a long
+wing-feather of some Bird, and their stalks or stems were, like those,
+bended backwards and downwards, as may be plainly seen by the draughts of
+them in the Figure.
+
+Observing one of these in my _Microscope_, I found, in the first place,
+that all the Body, Legs, Horns and the Stalks of the Wings, were covered
+over with various kinds of curious white Feathers, which did, with handling
+or touching, easily rubb off and fly about, in so much that looking on my
+Fingers, with which I had handled this Moth, and perceiving on them little
+white specks, I found by my _Microscope_, that they were several of the
+small Feathers of this little creature, that stuck up and down in the
+_rugosities_ of my Skin.
+
+Next, I found that underneath these Feathers, the pretty Insect was covered
+all over with a crusted Shell, like other of those Animals, but with one
+much thinner and tenderer.
+
+Thirdly, I found, as in Birds also is notable, it had differing and
+appropriate kinds of Feathers, that covered several parts of its body.
+
+Fourthly, surveying the parts of its body, with a more accurate and better
+Magnifying _Microscope_, I found that the tufts or haires of its Wings were
+nothing else but a congeries, or thick set cluster of small _vimina_ or
+twiggs, resembling a small twigg of Birch, stript or whitned, with which
+Brushes are usually made, to beat out or brush off the dust from Cloth and
+Hangings. Every one of the twiggs or branches that composed the Brush of
+the Feathers, appeared in this bigger Magnifying Glass (of which EF which
+represents œ4 part of an Inch, is the scale, as G is of the lesser, which
+is only 1/3) like the figure D. The Feathers also that covered a part of
+his Body, and were interspersed among the brush of his Wings, I found, in
+the bigger Magnifying Glass, of the shape A, consisting of a stalk or stem
+in the middle, and a seeming tuftedness or brushy part on each side. The
+Feathers that cover'd most part of his Body and the stalk of his wings,
+were, in the same _Microscope_, much of the figure B, appearing of the
+shape of a small Feather, and seemed tufted: those which covered the Horns
+and small parts of the Leggs, through the same _Microscope_, appear'd of
+the shape C. Whether the tufts of any or all of these small Feathers,
+consisted of such component particles as the Feathers of Birds, I much
+doubt, because I find that Nature does not alwaies keep, or operate after
+the same method, in smaller and bigger creatures. And of this, we have
+particular Instances in the Wings of several creatures. For whereas, in
+Birds of all kinds, it composes each of the Feathers of which its Wing
+consists, of such an exceeding curious and most admirable and stupendious
+texture, as I else where shew, in the Observations on a Feather; we find it
+to alter its method quite, in the fabrick of the Wings of these minute
+creatures, composing some of thin extended membranes or skins, such as the
+Wings of Dragon-flys; in others, those skins are all over-grown, or pretty
+thick bestuck, with short brisles, as in Flesh-flies; in others, those
+filmes are covered, both on the upper and under side, with small Feathers,
+plac'd almost like the tyles on a House, and are curiously rang'd and
+adorn'd with most lively colours, as is observable in Butter-flies, and
+several kinds of Moths; In others, instead of their films, Nature has
+provided nothing, but a matter of half a score stalks (if I well remember
+the number; for I have not lately met with any of these flys, and did not,
+when I first observ'd them, take sufficient notice of divers particulars)
+and each of these stalks, with a few single branchings on each side,
+resembling much the branched back-bone of a Herring or the like Fish, or a
+thin hair'd Peacocks feather, the top or the eye being broken off. With a
+few of these on either side (which it was able to shut up or expand at
+pleasure, much like a Fann, or rather like the posture of the feathers in a
+wing, whichly all one under another, when shut, and by the side of each
+other, when expanded) this pretty little grey Moth (for such was the
+creature I observ'd, thus wing'd) could very nimbly, and as it seem'd very
+easily move its _corpuscle_, through the Air, from place to place. Other
+Insects have their wings cas'd, or cover'd over, with certain hollow
+shells, shap'd almost like those hollow Trayes, in which Butchers carry
+meat, whose hollow sides being turn'd downwards, do not only secure their
+folded wings from injury of the earth, in which most of those creatures
+reside, but whilst they fly, serves as a help to sustain and bear them up.
+And these are observable in _Scarabees_ and a multitude of other
+terrestrial _crustaceous_ Insects; in which we may yet further observe a
+particular providence of Nature.
+
+Now in all these kinds of wings, we observe this particular, as a thing
+most worthy remark; that where ever a wing consists of discontinued parts,
+the Pores or _interstitia_ between those parts are very seldom, either much
+bigger, or much smaller, then these which we here find between the
+particles of these brushes, so that it should seem to intimate, that the
+parts of the Air are such, that they will not easily or readily, if at all,
+pass through these Pores, so that they seem to be strainers fine enough to
+hinder the particles of the Air (whether hinder'd by their bulk, or by
+their _agitation_, _circulation_, _rotation_ or _undulation_, I shall not
+here determine) from getting through them, and, by that means, serve the
+Animal as well, if not better, then if they were little films. I say, if
+not better, because I have observ'd that all those creatures, that have
+film'd wings, move them aboundantly quicker and more strongly, such as all
+kind of Flies and _Scarabees_ and Batts, then such as have their wings
+covered with feathers, as Butter-flies and Birds, or twiggs, as Moths,
+which have each of them a much slower motion of their wings; That little
+ruggedness perhaps of their wings helping them somewhat, by taking better
+hold of the parts of the Air, or not suffering them so easily to pass by,
+any other way then one.
+
+But what ever be the reason of it, 'tis most evident, that the smooth
+wing'd Insects, have the strongest Muscles or movent parts of their wings,
+and the other much weaker; and this very Insect, we are now describing, had
+a very small _thorax_ or middle part of his body, if compar'd to the length
+and number of his wings; which therefore, as he mov'd them very slowly, so
+must he move them very weakly. And this last propriety do we find somewhat
+observ'd also in bigger kind of Flying creatures, Birds; so that we see
+that the Wisdom and Providence of the All-wise Creator, is not less shewn
+in these small despicable creatures, Flies and Moths, which we have branded
+with a name of ignominy, calling them Vermine, then in those greater and
+more remakable animate bodies, Birds.
+
+I cannot here stand to add any thing about the nature of flying, though,
+perhaps, on another occasion, I may say something on that subject, it being
+such as may deserve a much more accurate examination and scrutiny then it
+has hitherto met with; For to me there seems nothing wanting to make a man
+able to fly, but what may be easily enough supply'd from the Mechanicks
+hitherto known, save onely the want of strength, which the Muscles of a man
+seem utterly uncapable of, by reason of their smalness and texture, but how
+even strength also may be mechanically made, and an artificial Muscle so
+contriv d, that thereby a man shall be able to exert what strength he
+pleases, and to regulate it also to his own mind, I may elsewhere endeavour
+to manifest.
+
+       *       *       *       *       *
+
+
+Observ. XLVII. _Of the _Shepherd Spider_, or long legg'd _Spider_._
+
+The Carter, Shepherd Spider, or long-legg'd Spider, has, for two
+particularities, very few similar creatures that I have met with, the
+first, which is discoverable onely by the _Microscope_, and is in the first
+and second _Figures_ of the 31. _Scheme_, plainly describ'd, is the curious
+contrivance of his eyes, of which (differing from most other Spiders) he
+has onely two, and those plac'd upon the top of a small pillar or hillock,
+rising out of the middle of the top of its back, or rather the crown of its
+head, for they were fix'd on the very top of this pillar (which is about
+the heighth of one of the transverse Diameters of the eye, and look'd on in
+another posture, appear'd much of the shape, BCD.) The two eyes, BB, were
+placed back to back, with the transparent parts, or the pupils, looking
+towards either side, but somewhat more forward then backwards. C was the
+column or neck on which they stood, and D the crown of the head out of
+which that neck sprung.
+
+These eyes, to appearance, seem'd to be of the very same structure with
+that of larger _binocular_ creatures, seeming to have a very smooth and
+very protuberant _Cornea_, and in the midst of it to have a very black
+pupil, incompassed about with a kind of grey _Iris_, as appears by the
+_Figure_; whether it were able to move these eyes to and fro, I have not
+observ'd, but 'tis not very likely he should, the pillar or neck C, seeming
+to be cover'd and stiffen'd with a crusty shell; but Nature, in
+probability, has supply'd that defect, by making the _Cornea_ so very
+protuberant, and setting it so cleer above the shadowing or obstructing of
+its prospect by the body, that 'tis likely each eye may perceive, though
+not see distinctly, almost a _Hemisphere_, whence having so small and round
+a body plac'd upon such long leggs, it is quickly able so to wind, and turn
+it, as to see any thing distinct. This creature, as do all other Spiders I
+have yet examin'd, does very much differ from most other Insects in the
+Figure of its eyes; for I cannot, with my best _Microscope_, discover its
+eyes to be any ways knobb'd or pearl'd like those of other Insects.
+
+The second Peculiarity which is obvious to the eye, is also very
+remarkable, and that is the prodigious length of its leggs, in proportion
+to its small round body, each legg of this I drew, being above sixteen
+times the length of its whole body, and there are some which have them yet
+longer, and others that seem of the same kind, that have them a great deal
+shorter; the eight leggs are each of them jointed, just like those of a
+Crab, but every of the parts are spun out prodigiously longer in
+proportion; each of these leggs are terminated in a small case or shell,
+shap'd almost like that of a Musle-shell, as is evident in the third
+_Figure_ of the same _Scheme_ (that represents the appearance ot the under
+part or belly of the creature) by the shape of the protuberant _conical_
+body, IIII, &c. These are as 'twere plac'd or fasten'd on to the
+protuberant body of the Insect, which is to be suppos'd very high at M,
+making a kind of blunt cone whereof M is to be suppos'd the _Apex_, about
+which greater cone of the body, the smaller cones of the leggs are plac'd,
+each of them almost reaching to the top in so admirable a manner, as does
+not a little manifest the wisdom of Nature in the contrivance; for these
+long Leavers (as I may so call them) of the legs, having not the advantage
+of a long end on the other side of the _hypomochlion_ or centers on which
+the parts of the leggs move, must necessarily require a vast strength to
+move them, and keep the body ballanc'd and suspended, in so much, that if
+we should suppose a man's body suspended by such a contrivance, an hundred
+and fifty times the strength of a man would not keep the body from falling
+on the breast. To supply therefore each of these leggs with its proper
+strength, Nature has allow'd to each a large Chest or Cell, in which is
+included a very large and strong Muscle, and thereby this little Animal is
+not onely able to suspend its body upon less then these eight, but to move
+it very swiftly over the tops of grass and leaves.
+
+Nor are these eight leggs so prodigiously long, but the ninth, and tenth,
+which are the two claws, KK, are as short, and serve in steed of a
+_proboscis_, for those seem'd very little longer then his mouth; each of
+them had three parts, but very short, the joints KK, which represented the
+third, being longer then both the other. This creature, seems (which I have
+several times with pleasure observ'd) to throw its body upon the prey,
+insteed of its hands, not unlike a hunting Spider, which leaps like a Cat
+at a Mouse. The whole Fabrick was a very pretty one, and could I have
+dissected it, I doubt not but I should have found as many singularities
+within it as without, perhaps, for the most part, not unlike the parts of a
+Crab, which this little creature does in many things, very much resemble;
+the curiosity of whose contrivance, I have in another place examin'd. I
+omit the description of the horns, AA, of the mouth, LL, which seem'd like
+that of a Crab; the speckledness of his shell, which proceeded from a kind
+of feathers or hairs, and the hairiness of his leggs, his large _thorax_
+and little belly, and the like, they being manifested by the Figure; and
+shall onely take notice that the three parts of the body, namely, the head,
+breast, and belly, are in this creature strangely confus'd, so that 'tis
+difficult to determine which is which, as they are also in a Crab; and
+indeed, this seems to be nothing else, but an Air-crab, being made more
+light and nimble, proportionable to the _medium_ wherin it resides; and as
+Air seems to have but one thousandth part of the body of Water, so does
+this Spider seem not to be a thousandth part of the bulk of a Crab.
+
+       *       *       *       *       *
+
+
+Observ. XLVIII. _Of the hunting _Spider_, and several other sorts of
+_Spiders_._
+
+The hunting Spider is a small grey Spider, prettily bespeck'd with black
+spots all over its body, which the _Microscope_ discovers to be a kind of
+feathers like those on Butterflies wings, or the body of the white Moth I
+lately describ'd. Its gate is very nimble by fits, sometimes running, and
+sometimes leaping, like a Grashopper almost, then standing still, and
+setting it self on its hinder leggs, it will very nimbly turn its body, and
+look round it self every way: It has six very conspicuous eyes, two looking
+directly forwards, plac'd just before; two other, on either side of those,
+looking forward and side-ways; and two other about the middle of the top of
+its back or head, which look backwards and side-wards; these seem'd to be
+the biggest. The surface of them all was very black, sphærical, purely
+polish'd, reflecting a very cleer and distinct Image of all the ambient
+objects, such as a window, a man's hand, a white Paper, or the like. Some
+other properties of this Spider, observ'd by the most accomplish'd Mr.
+_Evelyn_, in his travels in _Italy_, are most emphatically set forth in the
+History hereunto annexed, which he was pleas'd upon my desire to send me in
+writing.
+
+    Of all the sorts of Insects, there is none has afforded me more
+    divertisements then the _Venatores_, which are a sort of _Lupi_, that
+    have their Denns in the rugged walls, and crevices of our houses; a
+    small brown and delicately spotted kind of Spiders, whose hinder leggs
+    are longer then the rest.
+
+    Such I did frequently observe at _Rome_, which espying a Fly at three
+    or four yards distance, upon the Balcony (where I stood) would not make
+    directly to her, but craul under the Rail, till being arriv'd to the
+    _Antipodes_, it would steal up, seldom missing its aim; but if it
+    chanced to want any thing of being perfectly opposite, would at first
+    peep, immediatly slide down again, till taking better notice, it would
+    come the next time exactly upon the Fly's back: But, if this hapn'd not
+    to be within a competent leap, then would this Insect move so softly,
+    as the very shadow of the Gnomon seem'd not to be more imperceptible,
+    unless the Fly mov'd; and then would the Spider move also in the same
+    proportion, keeping that just time with her motion, as if the same Soul
+    had animated both those little bodies; and whether it were forwards,
+    backwards, or to either side, without at all turning her body, like a
+    well mannag'd Horse: But, if the capricious Fly took wing, and pitch'd
+    upon another place behind our Huntress, then would the Spider whirle
+    its body so nimbly about, as nothing could be imagin'd more swift; by
+    which means, she always kept the head towards her prey, though to
+    appearance, as immovable, as if it had been a Nail driven into the
+    Wood, till by that indiscernable progress (being arriv'd within the
+    sphere of her reach) she made a fatal leap (swift as Lightning) upon
+    the Fly, catching him in the pole, where she never quitted hold till
+    her belly was full, and then carried the remainder home. I have beheld
+    them instructing their young ones, how to hunt, which they would
+    sometimes discipline for not well observing; but, when any of the old
+    ones did (as sometimes) miss a leap, they would run out of the field,
+    and hide them in their crannies, as asham'd, and haply not be seen
+    abroad for four or five hours after; for so long have I watched the
+    nature of this strange Insect, the contemplation of whose so wonderfull
+    sagacity and address has amaz'd me; nor do I find in any chase
+    whatsoever, more cunning and Stratagem observ'd: I have found some of
+    these Spiders in my Garden, when the weather (towards the Spring) is
+    very hot, but they are nothing so eager of hunting as they are in
+    _Italy_.
+
+There are multitudes of other sorts of Spiders, whose eyes, and most other
+parts and properties, are so exceedingly different both from those I have
+describ'd, and from one another, that it would be almost endless, at least
+too long for my present Essay, to describe them, as some with six eyes,
+plac'd in quite another order; others with eight eyes; others with fewer,
+and some with more. They all seem to be creatures of prey, and to feed on
+other small Insects, but their ways of catching them seem very differing:
+the Shepherd Spider by running on his prey; the Hunting Spider by leaping
+on it, other sorts weave Nets, or Cobwebs, whereby they ensnare them,
+Nature having both fitted them with materials and tools, and taught them
+how to work and weave their Nets, and to lie perdue, and to watch
+diligently to run on any Fly, as soon as ever entangled.
+
+Their thread or web seems to be spun out of some viscous kind of excrement,
+lying in their belly, which, though soft when drawn out, is, presently by
+reason of its smallness, hardned and dried by the ambient Air. Examining
+several of which with my _Microscope_, I found them to appear much like
+white Hors-hair, or some such transparent horny substance, and to be of
+very differing magnitudes; some appearing as bigg as a Pigg's brisle,
+others equal to a Horss-hair; other no bigger then a man's hair; others yet
+smaller and finer. I observ'd further, that the radiating chords of the web
+were much bigger, and smoother then those that were woven round, which
+seem'd smaller, and all over knotted or pearl'd, with small transparent
+Globules, not unlike small Crystal Beads or seed Pearls, thin strung on a
+Clew of Silk; which, whether they were so spun by the Spider, or by the
+adventitious moisture of a fogg (which I have observ'd to cover all these
+filaments with such Crystalline Beads) I will not now dispute.
+
+These threads were some of them so small, that I could very plainly, with
+the _Microscope_, discover the same consecutions of colours as in a
+_Prisme_, and they seem'd to proceed from the same cause with those colours
+which I have already describ'd in thin plated bodies.
+
+Much resembling a Cobweb, or a confus'd lock of these Cylinders, is a
+certain white substance which, after a fogg, may be observ'd to fly up and
+down the Air; catching several of these, and examining them with my
+_Microscope_, I found them to be much of the same form, looking most like
+to a flake of Worsted prepar'd to be spun, though by what means they should
+be generated, or produc'd, is not easily imagined: they were of the same
+weight, or very little heavier then the Air; and 'tis not unlikely, but
+that those great white clouds, that appear all the Summer time, may be of
+the same substance.
+
+       *       *       *       *       *
+
+
+Observ. XLIX. _Of an _Ant_ or _Pismire_._
+
+This was a creature, more troublesom to be drawn, then any of the rest, for
+I could not, for a good while, think of a way to make it suffer its body to
+ly quiet in a natural posture; but whil'st it was alive, if its feet were
+fetter'd in Wax or Glew, it would so twist and wind its body, that I could
+not any wayes get a good view of it; and if I killed it, its body was so
+little, that I did often spoile the shape of it, before I could throughly
+view it: for this is the nature of these minute Bodies, that as soon,
+almost, as ever their life is destroy'd, their parts immediately shrivel,
+and lose their beauty; and so is it also with small Plants, as I instanced
+before, in the description of Moss. And thence also is the reason of the
+variations in the beards of wild Oats, and in those of Musk-grass seed,
+that their bodies, being exceeding small, those small variations which are
+made in the surfaces of all bodies, almost upon every change of Air,
+especially if the body be porous, do here become sensible, where the whole
+body is so small, that it is almost nothing but surface; for as in
+vegetable substances, I see no great reason to think, that the moisture of
+the Aire (that, sticking to a wreath'd beard, does make it untwist) should
+evaporate, or exhale away, any faster then the moisture of other bodies,
+but rather that the avolation from, or access of moisture to, the surfaces
+of bodies being much the same, those bodies become most sensible of it,
+which have the least proportion of body to their surface. So is it also
+with Animal substances; the dead body of an Ant, or such little creature,
+does almost instantly shrivel and dry, and your object shall be quite
+another thing, before you can half delineate it, which proceeds not from
+the extraordinary exhalation, but from the small proportion of body and
+juices, to the usual drying of bodies in the Air, especially if warm. For
+which inconvenience, where I could not otherwise remove it, I thought of
+this expedient.
+
+I took the creature, I had design'd to delineate, and put it into a drop of
+very well rectified spirit of Wine, this I found would presently dispatch,
+as it were, the Animal, and being taken out of it, and lay'd on a paper,
+the spirit of Wine would immediately fly away, and leave the Animal dry, in
+its natural posture, or at least, in a constitution, that it might easily
+with a pin be plac'd, in what posture you desired to draw it, and the limbs
+would so remain, without either moving, or shriveling. And thus I dealt
+with this Ant, which I have here delineated, which was one of many, of a
+very large kind, that inhabited under the Roots of a Tree, from whence they
+would sally out in great parties, and make most grievous havock of the
+Flowers and Fruits, in the ambient Garden, and return back again very
+expertly, by the same wayes and paths they went.
+
+It was more then half the bigness of an Earwig, of a dark brown, or reddish
+colour, with long legs, on the hinder of which it would stand up, and raise
+its head as high as it could above the ground, that it might stare the
+further about it, just after the same manner as I have also observ'd a
+hunting Spider to do: and putting my finger towards them, they have at
+first all run towards it, till almost at it; and then they would stand
+round about it, at a certain distance, and smell, as it were, and consider
+whether they should any of them venture any further, till one more bold
+then the rest venturing to climb it, all the rest, if I would have suffered
+them, would have immediately followed: many such other seemingly rational
+actions I have observ'd in this little Vermine with much pleasure, which
+would be too long to be here related; those that desire more of them may
+satisfie their curiosity in _Ligons_ History of the _Barbadoes_.
+
+Having insnar'd several of these into a small Box, I made choice of the
+tallest grown among them, and separating it from the rest, I gave it a Gill
+of Brandy, or Spirit of Wine, which after a while e'en knock'd him down
+dead drunk, so that he became moveless, though at first putting in he
+struggled for a pretty while very much, till at last, certain bubbles
+issuing out of its mouth, it ceased to move; this (because I had before
+found them quickly to recover again, if they were taken out presently) I
+suffered to lye above an hour in the Spirit; and after I had taken it out,
+and put its body and legs into a natural posture, remained moveless about
+an hour; but then, upon a sudden, as if it had been awaken out of a drunken
+sleep, it suddenly reviv'd and ran away; being caught, and serv'd as
+before, he for a while continued struggling and striving, till at last
+there issued several bubbles out of its mouth, and then, _tanquam animam
+expirasset_, he remained moveless for a good while; but at length again
+recovering, it was again redipt, and suffered to lye some hours in the
+Spirit; notwithstanding which, after it had layen dry some three or four
+hours, it again recovered life and motion: Which kind of Experiments, if
+prosecuted, which they highly deserve, seem to me of no inconsiderable use
+towards the invention of the _Latent Scheme_, (as the Noble _Verulam_ calls
+it) or the hidden, unknown Texture of Bodies.
+
+Of what Figure this Creature appear'd through the _Microscope_, the 32.
+_Scheme_ (though not so carefully graven as it ought) will represent to the
+eye, namely, That it had a large head AA, at the upper end of which were
+two protuberant eyes, pearl'd like those of a Fly, but smaller BB; out of
+the Nose, or foremost part, issued two horns CC, of a shape sufficiently
+differing from those of a blew Fly, though indeed they seem to be both the
+same kind of Organ, and to serve for a kind of smelling; beyond these were
+two indented jaws DD, which he open'd side-wayes, and was able to gape them
+asunder very wide; and the ends of them being armed with teeth, which
+meeting went between each other, it was able to grasp and hold a heavy
+body, three or four times the bulk and weight of its own body: It had only
+six legs, shap'd like those of a Fly, which, as I shewed before, is an
+Argument that it is a winged Insect, and though I could not perceive any
+sign of them in the middle part of its body (which seem'd to consist of
+three joints or pieces EFG, out of which sprung two legs), yet 'tis known
+that there are of them that have long wings, and fly up and down in the
+air.
+
+The third and last part of its body III was bigger and larger then the
+other two, unto which it was joyn'd by a very small middle, and had a kind
+of loose shell, or another distinct part of its body H, which seem'd to be
+interpos'd, and to keep the _thorax_ and belly from touching.
+
+The whole body was cas'd over with a very strong armour, and the belly III
+was covered likewise with multitudes of small white shining brisles; the
+legs, horns, head, and middle parts of its body were bestuck with hairs
+also, but smaller and darker.
+
+       *       *       *       *       *
+
+
+Observ. L. _Of the wandring _Mite_._
+
+In _September_ and _October, 1661._ I observ'd in _Oxford_ several of these
+little pretty Creatures to wander to and fro, and often to travel over the
+plains of my Window. And in _September_ and _October, 1663._ I observ'd
+likewise several of these very same Creatures traversing a window at
+_London_, and looking without the window upon the subjacent wall, I found
+whole flocks of the same kind running to and fro among the small groves and
+thickets of green moss, and upon the curiously spreading vegetable blew or
+yellow moss, which is a kind of a Mushrome or Jews-ear.
+
+These Creatures to the naked eye seemed to be a kind of black Mite, but
+much nimbler and stronger then the ordinary Cheese-Mites; but examining
+them in a _Microscope_, I found them to be a very fine crusted or shell'd
+Insect, much like that represented in the first Figure of the three and
+thirtieth _Scheme_, with a protuberant oval shell A, indented or pitted
+with an abundance of small pits, all covered over with little white
+brisles, whose points all directed backwards.
+
+It had eight legs, each of them provided with a very sharp tallon, or claw
+at the end, which this little Animal, in its going, fastned into the pores
+of the body over which it went. Each of these legs were bestuck in every
+joynt of them with multitudes of small hairs, or (if we respect the
+proportion they bore to the bigness of the leg) turnpikes, all pointing
+towards the claws.
+
+The _Thorax_, or middle parts of the body of this Creature, was exceeding
+small, in respect both of the head and belly, it being nothing but that
+part which was covered by the two shells BB, though it seem'd to grow
+thicker underneath: And indeed, if we consider the great variety Nature
+uses in proportioning the three parts of the body, (the _Head_, _Thorax_,
+and _Belly_) we shall not wonder at the small proportion of this _Thorax_,
+nor at the vaster bulk of the belly, for could we exactly anatomise this
+little Creature, and observe the particular designs of each part, we should
+doubtless, as we do in all her more manageable and tractable fabricks, find
+much more reason to admire the excellency of her contrivance and
+workmanship, then to wonder, it was not made otherwise.
+
+The head of this little Insect was shap'd somewhat like a Mite's, that is,
+it had a long snout, in the manner of a Hogs, with a knobbed ridge running
+along the middle of it, which was bestuck on either side with many small
+brisles, all pointing forward, and two very large pikes or horns, which
+rose from the top of the head, just over each eye, and pointed forward
+also. It had two pretty large black eyes on either side of the head EE,
+from one of which I could see a very bright reflection of the window, which
+made me ghess, that the _Cornea_ of it was smooth, like those of bigger
+Insects. Its motion was pretty quick and strong, it being able very easily
+to tumble a stone or clod four times as big as its whole body.
+
+At the same time and place, and divers times since, I have observed with my
+_Microscope_, another little Insect, which, though I have not annexed the
+picture of, may be worth noting, for its exceeding nimbleness as well as
+smalness; it was as small as a Mite, with a body deep and ridged, almost
+like a Flea; it had eight blood-red legs, not very long, but slender; and
+two horns or feelers before. Its motion was so exceeding quick, that I have
+often lost sight of one I have observed with my naked eye; and though, when
+it was not frighted, I was able to follow the motions of some with my
+_Microscope_; yet if it were never so little startled, it posted away with
+such speed, and turn'd and winded it self so quick, that I should presently
+lose sight of it.
+
+When I first observ'd the former of these Insects, or Mites, I began to
+conjecture, that certainly I had found out the vagabond Parents of those
+Mites we find in Cheeses, Meal, Corn, Seeds, musty Barrels, musty Leather,
+&c. these little Creatures, wandring to and fro every whither, might
+perhaps, as they were invited hither and thither by the musty steams of
+several putrifying bodies, make their invasions upon those new and pleasing
+territories, and there spending the remainder of their life, which might be
+perhaps a day, or thereabouts, in very plentiful and riotous living, might
+leave their off-spring behind them, which by the change of the soil and
+Country they now inhabite, might be quite alter'd from the hew of their
+_primogenitors_, and, like _Mores_ translated into Northern _European_
+Climates, after a little time, change both their skin and shape. And this
+seems yet more probable in these Insects, because that the soil or body
+they inhabit, seems to be almost half their parent, for it not only hatches
+and brings those little eggs, or seminal principles, to perfection, but
+seems to augment and nourish them also before they are hatch'd or shaped;
+for it is obvious enough to be observ'd, that the eggs of many other
+Insects, and particularly of Mites, are increas'd in bulk after they are
+laid out of the bodies of the Insects, and plump'd sometimes into many
+times their former bigness, so that the bodies they are laid in being, as
+it were, half their mothers, we shall not wonder that it should have such
+an active power to change their forms. We find by relations how much the
+_Negro_ Women do besmeer the of-spring of the _Spaniard_, bringing forth
+neither white-skinn'd nor black, but tawny hided _Mulattos_.
+
+Now, though I propound this as probable, I have not yet been so farr
+certify'd by Observations as to conclude any thing, either positively or
+negatively, concerning it. Perhaps, some more lucky diligence may please
+the curious Inquirer with the discovery of this, to be a truth, which I now
+conjecture, and may thereby give him a satisfactory account of the cause of
+those creatures, whose original seems yet to obscure, and may give him
+cause to believe, that many other animate beings, that seem also to be the
+mere product of putrifaction, may be innobled with a Pedigree as ancient as
+the first creation, and farr exceed the greatest beings in their numerous
+Genealogies. But on the other side, if it should be found that these, or
+any other animate body, have no immediate similar Parent, I have in another
+place set down a conjectural _Hypothesis_ whereby those _Phænomena_ may
+likely enough be solv'd, wherein the infinite wisdom and providence of the
+Creator is no less rare and wonderfull.
+
+       *       *       *       *       *
+
+
+Observ. LI. _Of the _Crab-like_ Insect._
+
+Reading one day in _Septemb._ I chanced to observe a very smal creature
+creep over the Book I was reading, very slowly; having a _Microscope_ by
+me, I observ'd it to be a creature of a very unusual form, and that not
+less notable; such as is describ'd in the second _Figure_ of the 33.
+_Scheme_. It was about the bigness of a large Mite, or somewhat longer, it
+had ten legs, eight of which, AAAA, were topt with very sharp claws, and
+were those upon which he walk'd, seeming shap'd much like those of a Crab,
+which in many other things also this little creature resembled; for the two
+other claws, BB, which were the formost of all the ten, and seem'd to grow
+out of his head, like the horns of other Animals, were exactly form'd in
+the manner of Crabs or Lobsters claws, for they were shap'd and jointed
+much like those represented in the _Scheme_ and the ends of them were
+furnish'd with a pair of claws or pincers, CC, which this little animal did
+open and shut at pleasure: It seem'd to make use of those two horns or
+claws both for feelers and holders; for in its motion it carried these
+aloft extended before, moving them to and fro, just as a man blindfolded
+would do his hands when he is fearfull of running against a wall, and if I
+put a hair to it, it would readily take hold of it with these claws, and
+seem to hold it fast. Now, though these horns seem'd to serve him for two
+uses, namely, for feeling and holding; yet he seem'd neither blind, having
+two small black spots, DD, which by the make of them, and the bright
+reflection from them seem'd to be his eyes, nor did it want other hands,
+having another pair of claws, EE, very neer plac'd to its mouth, and seem'd
+adjoining to it.
+
+The whole body was cased over with armour-shells, as is usuall in all those
+kinds of _crustaceous_ creatures, especially about their bellies, and
+seem'd of three kinds, the head F seem'd cover'd with a kind of scaly
+shell, the _thorax_ with two smooth shells, or Rings, GG, and the belly
+with eight knobb'd ones. I could not certainly find whether it had under
+these last shells any wings, but I suspect the contrary; for I have not
+found any wing'd Insect with eight leggs, two of those leggs being always
+converted into wings, and, for the most part, those that have but six, have
+wings.
+
+This creature, though I could never meet with more then one of them, and so
+could not make so many examinations of it as otherwise I would, I did
+notwithstanding, by reason of the great curiosity that appear'd to me in
+its shape, delineate it, to shew that, in all likelihood, Nature had
+crouded together into this very minute Insect, as many, and as excellent
+contrivances, as into the body of a very large Crab, which exceeds it in
+bulk, perhaps, some Millions of times; for as to all the apparent parts,
+there is a greater rather then a less multiplicity of parts, each legg has
+as many parts, and as many joints as a Crabs, nay, and as many hairs or
+brisles; and the like may be in all the other visible parts; and 'tis very
+likely, that the internal curiosities are not less excellent: It being a
+general rule in Nature's proceedings, that where she begins to display any
+excellency, if the subject be further search'd into, it will manifest, that
+there is not less curiosity in those parts which our single eye cannot
+reach, then in those which are more obvious.
+
+       *       *       *       *       *
+
+
+Observ. LII. _Of the small Silver-colour'd _Book-worm_._
+
+As among greater Animals there are many that are scaled, both for ornament
+and defence, so are there not wanting such also among the lesser bodies of
+Insects, whereof this little creature gives us an Instance. It is a small
+white Silver-shining Worm or Moth, which I found much conversant among
+Books and Papers, and is suppos'd to be that which corrodes and eats holes
+through the leaves and covers; it appears to the naked eye, a small
+glittering Pearl-colour'd Moth, which upon the removing of Books and Papers
+in the Summer, is often observ'd very nimbly to scud, and pack away to some
+lurking cranney, where it may the better protect itself from any appearing
+dangers. Its head appears bigg and blunt, and its body tapers from it
+towads the tail, smaller and smaller, being shap'd almost like a Carret.
+
+This the _Microscopical_ appearance will more plainly manifest, which
+exhibits, in the third _Figure_ of the 33. _Scheme_, a conical body,
+divided into fourteen several partitions, being the appearance of so many
+several shels, or shields that cover the whole body, every of these shells
+are again cover'd or tiled over with a multitude of thin transparent
+scales, which, from the multiplicity of their reflecting surfaces, make the
+whole Animal appear of a perfect Pearl-colour.
+
+Which, by the way, may hint us the reason of that so much admired
+appearance of those so highly esteem'd bodies, as also of the like in
+mother of Pearl-shells, and in multitudes of other shelly Sea-substances;
+for they each of them consisting of an infinite number of very thin shells
+or laminated orbiculations, cause such multitudes of reflections, that the
+compositions of them together with the reflections of others that are so
+thin as to afford colours (of which I elsewhere give the reason) gives a
+very pleasant reflection of light. And that this is the true cause, seems
+likely, first, because all those so appearing bodies are compounded of
+multitudes of plated substances. And next that, by ordering any trasparent
+substance after this manner, the like _Phænomena_ may be produc'd; this
+will be made very obvious by the blowing of Glass into exceeding thin
+shells, and then breaking them into scales, which any lamp-worker will
+presently do; for a good quantity of these scales, laid in a heap together,
+have much the same resemblance of Pearls. Another way, not less instructive
+and pleasant, is a way which I have several times done, which is by working
+and tossing, as 'twere, a parcel of pure crystalline glass whilst it is
+kept glowing hot in the blown flame of a Lamp, for, by that means, that
+purely transparent body will be so divided into an infinite number of
+plates, or small strings, with interpos'd aerial plates and _fibres_, that
+from the multiplicity of the reflections from each of those internal
+surfaces, it may be drawn out into curious Pearl-like or Silver wire, which
+though small, will yet be opacous; the same thing I have done with a
+composition of red _Colophon_ and _Turpentine_, and a little Bee's Wax, and
+may be done likewise with Birdlime, and such like glutinous and transparent
+bodies: But to return to our description.
+
+The small blunt head of this Insect was furnish'd on either side of it with
+a cluster of eyes, each of which seem'd to contain but a very few, in
+comparison of what I had observ'd the clusters of other Insects to abound
+with; each of these clusters were beset with a row of small brisles, much
+like the _cilia_ or hairs on the eye-lids, and, perhaps, they serv'd for
+the same purpose. It had two long horns before, which were streight, and
+tapering towards the top, curiously ring'd or knobb'd, and brisled much
+like the Marsh Weed, call'd Horse-tail, or Cats-tail, having at each knot a
+fring'd Girdle, as I may so call it, of smaller hairs, and several bigger
+and larger brisles, here and there dispers'd among them: besides these, it
+had two shorter horns, or feelers, which were knotted and fring'd, just as
+the former, but wanted brisles, and were blunt at the ends; the hinder part
+of the creature was terminated with three tails, in every particular
+resembling the two longer horns that grew out of the head: The leggs of it
+were scal'd and hair'd much like the rest, but are not express'd in this
+_Figure_, the Moth being intangled all in Glew, and so the leggs of this
+appear'd not through the Glass which looked perpendicularly upon the back.
+
+This Animal probably feeds upon the Paper and covers of Books, and
+perforates in them several small round holes, finding, perhaps, a
+convenient nourishment in those hulks of Hemp and Flax, which have pass'd
+through so many scourings, washings, dressings and dryings, as the parts of
+old Paper must necessarily have suffer'd; the digestive faculty, it seems,
+of these little creatures being able yet further to work upon those
+stubborn parts, and reduce them into another form.
+
+And indeed, when I consider what a heap of Saw-dust or chips this little
+creature (which is one of the teeth of Time) conveys into its intrals, I
+cannot chuse but remember and admire the excellent contrivance of Nature,
+in placing in Animals such a fire, as is continually nourished and supply'd
+by the materials convey'd into the stomach, and _fomented_ by the bellows
+of the lungs; and in so contriving the most admirable fabrick of Animals,
+as to make the very spending and wasting of that fire, to be instrumental
+to the procuring and collecting more materials to augment and cherish it
+self, which indeed seems to be the principal end of all the contrivances
+observable in bruit Animals.
+
+       *       *       *       *       *
+
+
+Observ. LIII. _Of a _Flea_._
+
+The strength and beauty of this small creature, had it no other relation at
+all to man, would deserve a description.
+
+For its strength, the _Microscope_ is able to make no greater discoveries
+of it then the naked eye, but onely the curious contrivance of its leggs
+and joints, for the exerting that strength, is very plainly manifested,
+such as no other creature, I have yet observ'd, has any thing like it; for
+the joints of it are so adapted, that he can, as 'twere, fold them short
+one within another, and suddenly stretch, or spring them out to their whole
+length, that is, of the fore-leggs, the part A, of the 34. _Scheme_, lies
+within B, and B within C, parallel to, or side by side each other; but the
+parts of the two next, lie quite contrary, that is, D without E, and E
+without F, but parallel also; but the parts of the hinder leggs, G, H and
+I, bend one within another, like the parts of a double jointed Ruler, or
+like the foot, legg and thigh of a man; these six leggs he clitches up
+altogether, and when he leaps, springs them all out, and thereby exerts his
+whole strength at once.
+
+But, as for the beauty of it, the _Microscope_ manifests it to be all over
+adorn'd with a curiously polish'd suit of _sable_ Armour, neatly jointed,
+and beset with multitudes of sharp pinns, shap'd almost like Porcupine's
+Quills, or bright conical Steel-bodkins; the head is on either side
+beautify'd with a quick and round black eye K, behind each of which also
+appears a small cavity, L, in which he seems to move to and fro a certain
+thin film beset with many small transparent hairs, which probably may be
+his ears; in the forepart of his head, between the two fore-leggs, he has
+two small long jointed feelers, or rather smellers, MM, which have four
+joints, and are hairy, like those of several other creatures; between
+these, it has a small _proboscis_, or _probe_, NNO, that seems to consist
+of a tube NN, and a tongue or sucker O, which I have perceiv'd him to slip
+in and out. Besides these, it has also two chaps or biters PP, which are
+somewhat like those of an Ant, but I could not perceive them tooth'd; these
+were shap'd very like the blades of a pair of round top'd Scizers, and were
+opened and shut just after the same manner; with these Instruments does
+this little busie Creature bite and pierce the skin, and suck out the blood
+of an Animal, leaving the skin inflamed with a small round red spot. These
+parts are very difficult to be discovered, because, for the most part, they
+lye covered between the fore-legs. There are many other particulars, which,
+being more obvious, and affording no great matter of information, I shall
+pass by, and refer the Reader to the Figure.
+
+       *       *       *       *       *
+
+
+Observ. LIV. _Of a Louse._
+
+This is a Creature so officious, that 'twill be known to every one at one
+time or other, so busie, and so impudent, that it will be intruding it self
+in every ones company, and so proud and aspiring withall, that it fears not
+to trample on the best, and affects nothing so much as a Crown; feeds and
+lives very high, and that makes it so saucy, as to pull any one by the ears
+that comes in its way, and will never be quiet till it has drawn blood: it
+is troubled at nothing so much as at a man that scratches his head, as
+knowing that man is plotting and contriving some mischief against it, and
+that makes it oftentime sculk into some meaner and lower place, and run
+behind a mans back, though it go very much against the hair; which ill
+conditions of it having made it better known then trusted, would exempt me
+from making any further description of it, did not my faithful _Mercury_,
+my _Microscope_, bring me other information of it. For this has discovered
+to me, by means of a very bright light cast on it, that it is a Creature of
+a very odd shape; it has a head shap'd like that exprest in 35. _Scheme_
+marked with A, which seems almost Conical, but is a little flatted on the
+upper and under sides, at the biggest part of which, on either side behind
+the head (as it were, being the place where other Creatures ears stand) are
+placed its two black shining goggle eyes BB, looking backwards, and fenced
+round with several small _cilia_, or hairs that incompass it, so that it
+seems this Creature has no very good foresight: It does not seem to have
+any eye-lids, and therefore perhaps its eyes were so placed, that it might
+the better cleanse them with its fore-legs; and perhaps this may be the
+reason, why they so much avoid and run from the light behind them, for
+being made to live in the shady and dark recesses of the hair, and thence
+probably their eye having a great aperture, the open and clear light,
+especially that of the Sun, must needs very much offend them; to secure
+these eyes from receiving any injury from the hairs through which it
+passes, it has two horns that grow before it, in the place where one would
+have thought the eyes should be; each of these CC hath four joynts, which
+are fringed, as 'twere, with small brisles, from which to the tip of its
+snout D, the head seems very round and tapering, ending in a very sharp
+nose D, which seems to have a small hole, and to be the passage through
+which he sucks the blood. Now whereas if it be plac'd on its back, with its
+belly upwards, as it is in the 35. _Scheme_, it seems in several Positions
+to have a resemblance of chaps, or jaws, as is represented in the Figure by
+EE, yet in other postures those dark strokes disappear; and having kept
+several of them in a box for two or three dayes, so that for all that time
+they had nothing to feed on, I found, upon letting one creep on my hand,
+that it immediately fell to sucking, and did neither seem to thrust its
+nose very deep into the skin, nor to open any kind of mouth, but I could
+plainly perceive a small current of blood, which came directly from its
+snout, and past into its belly; and about A there seem'd a contrivance,
+somewhat resembling a Pump, pair of Bellows, or Heart, for by a very swift
+_systole_ and _diastole_ the blood seem'd drawn from the nose, and forced
+into the body. It did not seem at all, though I viewed it a good while as
+it was sucking, to thrust more of its nose into the skin then the very
+snout D, nor did it cause the least discernable pain, and yet the blood
+seem'd to run through its head very quick and freely, so that it seems
+there is no part of the skin but the blood is dispers'd into, nay, even
+into the _cuticula_; for had it thrust its whole nose in from D to CC, it
+would not have amounted to the supposed thickness of that _tegument_, the
+length of the nose being not more then a three hundredth part of an inch.
+It has six legs, covered with a very transparent shell, and joynted exactly
+like a Crab's, or Lobster's; each leg is divided into six parts by these
+joynts, and those have here and there several small hairs; and at the end
+of each leg it has two claws, very properly adapted for its peculiar use,
+being thereby inabled to walk very securely both on the skin and hair; and
+indeed this contrivance of the feet is very curious, and could not be made
+more commodiously and compendiously, for performing both these requisite
+motions, of walking and climbing up the hair of a mans head, then it is:
+for, by having the lesser claw (a) set so much short of the bigger (b) when
+it walks on the skin the shorter touches not, and then the feet are the
+same with those of a Mite, and several other small Insects, but by means of
+the small joynts of the longer claw it can bend it round, and so with both
+claws take hold of a hair, in the manner represented in the Figure, the
+long transparent Cylinder FFF, being a Man's hair held by it.
+
+The _Thorax_ seem'd cas'd with another kind of substance then the belly,
+namely, with a thin transparent horny substance, which upon the fasting of
+the Creature did not grow flaccid; through this I could plainly see the
+blood, suck'd from my hand, to be variously distributed, and mov'd to and
+fro; and about G there seem'd a pretty big white substance, which seem'd to
+be moved within its _thorax_; besides, there appear'd very many small
+milk-white vessels, which crost over the breast between the legs, out of
+which, on either side, were many small branchings, these seem'd to be the
+veins and arteries, for that which is analogus to blood in all Insects is
+milk-white.
+
+The belly is covered with a transparent substance likewise, but more
+resembling a skin then a shell, for 'tis grain'd all over the belly just
+like the skin in the palms of a man's hand, and when the belly is empty,
+grows very flaccid and wrinkled; at the upper end of this is placed the
+stomach HH, and perhaps also the white spot II may be the liver or
+_pancreas_, which, by the _peristalick_ motion of the guts, is a little
+mov'd to and fro, not with a _systole_ and _diastole_, but rather with a
+thronging or justling motion. Viewing one of these Creatures, after it had
+fasted two dayes, all the hinder part was lank and flaccid, and the white
+spot II hardly mov'd, most of the white branchings disappear'd, and most
+also of the redness or sucked blood in the guts, the _peristaltick_ motion
+of which was scarce discernable; but upon the suffering it to suck, it
+presently fill'd the skin of the belly, and of the six scolop'd embosments
+on either side, as full as it could be stuft, the stomach and guts were as
+full as they could hold; the _peristaltick_ motion of the gut grew quick,
+and the justling motion of II accordingly; multitudes of milk-white vessels
+seem'd quickly filled, and turgid, which were perhaps the veins and
+arteries and the Creature was so greedy, that though it could not contain
+more, yet it continued sucking as fast as ever, and as fast emptying it
+self behind: the digestion of this Creature must needs be very quick, for
+though I perceiv'd the blood thicker and blacker when suck'd, yet, when in
+the guts, it was of a very lovely ruby colour, and that part of it, which
+was digested into the veins, seemed white; whence it appears, that a
+further digestion of blood may make it milk, at least of a resembling
+colour: What is else observable in the figure of this Creature, may be seen
+by the 35. _Scheme_.
+
+       *       *       *       *       *
+
+
+Observ. LV. _Of _Mites_._
+
+The least of _Reptiles_ I have hitherto met with, is a Mite, a Creature
+whereof there are some so very small, that the sharpest sight, unassisted
+with Glasses, is not able to discern them, though, being white of
+themselves, they move on a black and smooth surface; and the Eggs, out of
+which these Creatures seem to be hatch'd, are yet smaller, those being
+usually not above a four or five hundredth part of a well grown Mite, and
+those well grown Mites not much above one hundredth of an inch in
+thickness; so that according to this reckoning there may be no less then a
+million of well grown Mites contain'd in a cubick inch, and five hundred
+times as many Eggs.
+
+Notwithstanding which minuteness a good _Microscope_ discovers those small
+movable specks to be very prettily shap'd Insects, each of them furnished
+with eight well shap'd and proportion'd legs, which are each of them
+joynted or bendable in eight several places, or joynts, each of which is
+covered, for the most part, with a very transparent shell, and the lower
+end of the shell of each joynt is fringed with several small hairs; the
+contrivance of the joynts seems the very same with that of Crabs and
+Lobsters legs, and like those also, they are each of them terminated with a
+very sharp claw or point; four of these legs are so placed, that they seem
+to draw forwards, the other four are placed in a quite contrary position,
+thereby to keep the body backwards when there is occasion.
+
+[15]The body, as in other larger Insects, consists of three regions or
+parts; the hinder or belly A, seems covered with one intire shell, the
+middle, or chest, seems divided into two shells BC. which running one
+within the other, the Mite is able to shrink in and thrust out as it finds
+occasion, as it can also the snout D. The whole body is pretty transparent,
+so that being look'd on against the light, divers motions within its body
+may be perceived; as also all the parts are much more plainly delineable,
+then in other postures, to the light. The shell, especially that which
+covers the back, is curiously polisht, so that 'tis easie to see, as in a
+_convex_ Looking-glass, or _foliated_ Glass-ball, the picture of all the
+objects round about; up and down, in several parts of its body, it has
+several small long white hairs growing out of its shell, which are often
+longer then the whole body, and are represented too short in the first and
+second Figures; they seem all pretty straight and plyable, save only two
+upon the fore-part of its body, which seem to be the horns, as may be seen
+in the Figures; the first whereof is a prospect of a smaller sort of Mites
+(which are usually more plump) as it was _passant_ to and fro; the second
+is the prospect of one fixt on its tail (by means of a little mouth-glew
+rub'd on the object plate) exhibiting the manner of the growing of the
+legs, together with their several joynts.
+
+This Creature is very much diversify'd in shape, colour, and divers other
+properties, according to the nature of the substance out of which it seems
+to be ingendred and nourished, being in one substance more long, in another
+more round, in some more hairy, in others more smooth, in this nimble, in
+that slow, here pale and whiter, there browner, blacker, more transparent,
+&c. I have observed it to be resident almost on all kinds of substances
+that are mouldy, or putrifying, and have seen it very nimbly meshing
+through the thickets of mould, and sometimes to lye _dormant_ underneath
+them; and 'tis not unlikely, but that it may feed on that vegetating
+substance, _spontaneous Vegetables_ seeming a food proper enough for
+_spontaneous Animals_,
+
+But whether indeed this Creature, or any other, be such or not, I cannot
+positively, from any Experiment, or Observation, I have yet made,
+determine. But, as I formerly hinted, it seems probable, that some kind of
+wandring Mite may sow, as 'twere, the first seeds, or lay the first eggs,
+in those places, which Nature has instructed them to know convenient for
+the hatching and nourishing their young; and though perhaps the prime
+Parent might be of a shape very differing from what the offspring, after a
+little while, by reason of the substance they feed on, or the Region (as
+'twere) they inhabite; yet perhaps even one of these alter'd progeny,
+wandering again from its native soil, and lighting on by chance the same
+place from whence its prime Parent came, and there settling, and planting,
+may produce a generation of Mites of the same shapes and properties with
+the first wandring Mite: And from some such accidents as these, I am very
+apt to think, the most sorts of Animals, generally accounted _spontaneous_,
+have their _origination_, and all those various sorts of Mites, that are to
+be met with up and down in divers putrifying substances, may perhaps be all
+of the same kind, and have sprung from one and the same sort of Mites at
+the first.
+
+       *       *       *       *       *
+
+
+Observ. LVI. _Of a small Creature hatch'd on a Vine._
+
+There is, almost all the Spring and Summer time, a certain small, round,
+white Cobweb, as 'twere, about the bigness of a Pea, which sticks very
+close and fast to the stocks of Vines nayl'd against a warm wall: being
+attentively viewed, they seem cover'd, upon the upper side of them, with a
+small husk, not unlike the scale, or shell of a Wood-louse, or Hog-louse, a
+small Insect usually found about rotten wood, which upon touching presently
+rouls it self into the form of a peppercorn: Separating several of these
+from the stock, I found them, with my _Microscope_, to consist of a shell,
+which now seemed more likely to be the husk of one of these Insects: And
+the fur seem'd a kind of cobweb, consisting of abundance of small
+filaments, or sleaves of cobwebs. In the midst of this, if they were not
+hatch'd, and run away before, the time of which hatching was usually about
+the latter end of _June_, or beginning of _July_, I have often found
+abundance of small brown Eggs, such as A and B in the second Figure of the
+36. _Scheme_, much about the bigness of Mites Eggs; and at other times,
+multitudes of small Insects, shaped exactly like that in the third Figure
+marked with X. Its head large, almost half the bigness of its body, which
+is usual in the _foetus_ of most Creatures. It had two small black eyes
+_aa_, and two small long joynted and brisled horns _bb_. The hinder part of
+its body seem'd to consist of nine scales, and the last ended in a forked
+tayl, much like that of a _Cutio_, or Wood louse, out of which grew two
+long hairs; they ran to and fro very swiftly, and were much of the bigness
+of a common Mite, but some of them less: The longest of them seem'd not the
+hundredth part of an inch, and the Eggs usually not above half as much.
+They seemed to have six legs, which were not visible in this I have here
+delineated, by reason they were drawn under its body.
+
+If these Minute creatures were _Wood-lice_ (as indeed from their own shape
+and from the frame, the skin, or shell, that grows on them, one may with
+great probability ghess) it affords us an Instance, whereof perhaps there
+are not many like in Nature, and that is, of the prodigious increase of
+these Creatures, after they are hatch'd and run about; for a common
+Wood-louse, of about half an inch long, is no less then a hundred and
+twenty five thousand times bigger then one of these, which though indeed it
+seems very strange, yet I have observed the young ones of some Spiders have
+almost kept the same proportion to their Dam.
+
+This, methinks, if it be so, does in the next place hint a Quæry, which may
+perhaps deserve a little further examination: And that is, Whether there be
+not many of those minute Creatures, such as Mites, and the like, which,
+though they are commonly thought of otherwise, are only the _pully_, or
+young ones, of much bigger Insects, and not the generating, or parent
+_Insect_, that has layd those Eggs; for having many times observ'd those
+Eggs, which usually are found in great abundance where Mites are found, it
+seems something strange, that so small an Animal should have an Egg so big
+in proportion to its body. Though on the other side, I must confess, that
+having kept divers of those Mites inclosed in a box for a good while, I did
+not find them very much augmented beyond their usual bigness.
+
+What the husk and cobweb of this little white substance should be, I cannot
+imagine, unless it be, that the old one, when impregnated with Eggs, should
+there stay, and fix it self on the Vine, and dye, and all the body by
+degrees should rot, save only the husk, and the Eggs in the body: And the
+heat, or fire, as it were, of the approaching Sun-beams should vivifie
+those Relicts of the corrupted Parent, and out of the ashes, as 'twere, (as
+it is fabled of the _Phoenix_) should raise a new _offspring_ for the
+perpetuation of the _Species_. Nor will the cobweb, as it were, in which
+these Eggs are inclos'd, make much against this Conjecture; for we may, by
+those cobwebs that are carried up and down the Air after a Fog (which with
+my _Microscope_ I have discovered to be made up of an infinite company of
+small filaments or threads) learn, that such a texture of body may be
+otherwise made then by the spinning of a Worm.
+
+       *       *       *       *       *
+
+
+Observ. LVII. _Of the _Eels_ in Vinegar._
+
+Of these small Eels, which are to be found in divers sorts of Vinegar, I
+have little to add besides their Picture, which you may find drawn in the
+third Figure of the 25. _Scheme_: That is, they were shaped much like an
+Eel, save only that their nose A, (which was a little more opacous then the
+rest of their body) was a little sharper, and longer, in proportion to
+their body, and the wrigling motion of their body seem'd to be onely
+upwards and downwards, whereas that of Eels is onely side wayes: They
+seem'd to have a more opacous part about B, which might, perhaps, be their
+Gills; it seeming always the same proportionate distant from their nose,
+from which, to the tip of their tail, C, their body seem'd to taper.
+
+Taking several of these out of their Pond of Vinegar, by the net of a small
+piece of filtring Paper, and laying them on a black smooth Glass plate, I
+found that they could wriggle and winde their body, as much almost as a
+Snake, which made me doubt, whether they were a kind of Eal or Leech.
+
+I shall add no other observations made on this minute Animal, being
+prevented herein by many excellent ones already publish'd by the ingenious,
+Doctor _Power_, among his _Microscopical_ Observations, save onely that a
+quantity of Vinegar repleat with them being included in a small Viol, and
+stop'd very close from the ambient air, all the included Worms in a very
+short time died, as if they had been stifled.
+
+And that their motion seems (contrary to what we may observe in the motion
+of all other Infects) exceeding slow. But the reason of it seems plain, for
+being to move to and fro after that manner which they do, by waving onely,
+or wrigling their body; the tenacity, or glutinousness, and the density or
+resistance of the fluid _medium_ becomes so exceeding sensible to their
+extremely minute bodies, that it is to me indeed a greater wonder that they
+move them so fast as they do, then that they move them no faster. For what
+a vastly greater proportion have they of their superficies to their bulk,
+then Eels or other larger Fishes, and next, the tenacity and density of the
+liquor being much the same to be moved, both by the one and the other, the
+resistance or impediment thence arising to the motions made through it,
+must be almost infinitely greater to the small one then to the great. This
+we find experimentally verify'd in the Air, which though a _medium_ a
+thousand times more rarify'd then the water, the resistance of it to
+motions made through it, is yet so sensible to very minute bodies, that a
+Down-feather (the least of whose parts seem yet bigger then these Eels, and
+many of them almost incomparably bigger, such as the quill and stalk) is
+suspended by it, and carried to and fro as if it had no weight.
+
+       *       *       *       *       *
+
+
+Observ. LVIII. _Of a new Property in the _Air_, and several other
+transparent _Mediums_ nam'd _Inflection_, whereby very many considerable
+_Phænomena_ are attempted to be solv'd, and divers other uses are hinted._
+
+Since the Invention (and perfecting in some measure) of _Telescopes_, it
+has been observ'd by several, that the Sun and Moon neer the Horizon, are
+disfigur'd (losing that exactly-smooth terminating circular limb, which
+they are observ'd to have when situated neerer the Zenith) and are bounded
+with an edge every way (especially upon the right and left sides) ragged
+and indented like a Saw: which inequality of their limbs, I have further
+observ'd, not to remain always the same, but to be continually chang'd by a
+kind of fluctuating motion, not unlike that of the waves of the Sea, so as
+that part of the limb, which was but even now nick'd or indented in, is now
+protuberant, and will presently be sinking again; neither is this all but
+the whole body of the Luminaries, do in the _Telescope_, seem to be
+depress'd and slatted, the upper, and more especially the under side
+appearing neerer to the middle then really they are, and the right and left
+appearing more remote: whence the whole _Area_ seems to be terminated by a
+kind of Oval. It is further observ'd, that the body, for the most part,
+appears red, or of some colour approaching neer unto it, as some kind of
+yellow; and this I have always mark'd, that the more the limb is slatted or
+ovalled, the more red does the body appear, though not always the contrary.
+It is further observable, that both fix'd Stars and Planets, the neerer
+they appear to the Horizon, the more red and dull they look, and the more
+they are observ'd to twinkle; in so much, that I have seen the Dog-starr to
+vibrate so strong and bright a radiation of light, as almost to dazle my
+eyes, and presently, almost to disappear. It is also observable, that those
+bright scintillations neer the Horizon, are not by much so quick and sudden
+in their consecutions of one another, as the nimbler twinklings of Stars
+neerer the Zenith. This is also notable, that the Starrs neer the Horizon,
+are twinkled with several colours; so as sometimes to appear red, sometimes
+more yellow, and sometimes blue, and this when the Starr is a pretty way
+elevated above the Horizon. I have further, very often seen some of the
+small Starrs of the fifth or sixth magnitude, at certain times to disappear
+for a small moment of time, and again appear more conspicuous, and with a
+greater luster. I have several times, with my naked eye, seen many smaller
+Starrs, such as may be call'd of the seventh or eighth magnitude to appear
+for a short space, and then vanish, which, by directing a small _Telescope_
+towards that part they appear'd and disappear'd in; I could presently find
+to be indeed small Starrs so situate, as I had seen them with my naked eye,
+and to appear twinkling like the ordinary visible Stars; nay, in examining
+some very notable parts of the Heaven, with a three foot Tube, me thought I
+now and then, in several parts of the constellation, could perceive little
+twinklings of Starrs, making a very short kind of apparition, and presently
+vanishing, but noting diligently the places where they thus seem'd to play
+at boe-peep, I made use of a very good twelve foot Tube, and with that it
+was not uneasie to see those, and several other degrees of smaller Starrs,
+and some smaller yet, that seem'd again to appear and disappear, and these
+also by giving the same Object-glass a much bigger aperture, I could
+plainly and constantly see appear in their former places; so that I have
+observ'd some twelve several magnitudes of Starrs less then those of the
+six magnitudes commonly recounted in the Globes.
+
+It has been observ'd and confirm'd by the accuratest Observations of the
+best of our modern Astronomers, that all the Luminous bodies appear above
+the Horizon, when they really are below it. So that the Sun and Moon have
+both been seen above the Horizon, whil'st the Moon has been in an Eclipse.
+I shall not here instance in the great refractions, that the tops of high
+mountains, seen at a distance, have been found to have; all which seem to
+argue the Horizontal refraction, much greater then it is hitherto generally
+believ'd.
+
+I have further taken notice, that not onely the Sun, Moon and Starrs, and
+high tops of mountains have suffer'd these kinds of refraction, but Trees,
+and several bright Objects on the ground: I have often taken notice of the
+twinkling of the reflections of the Sun from a Glass-window at a good
+distance, and of a Candle in the night, but that is not so conspicuous, and
+in observing the setting Sun, I have often taken notice of the tremulation
+of the Trees and Bushes, as well as of the edges of the Sun. Divers of
+these _Phænomena_ have been taken notice of by several, who have given
+several reasons of them, but I have not yet met with any altogether
+satisfactory, though some of their conjectures have been partly true, but
+partly also false. Setting my self therfore upon the inquiry of these
+_Phænomena_, I first endeavour'd to be very diligent in taking notice of
+the several particulars and circumstances observable in them; and next, in
+making divers particular Experiments, that might cleer some doubts, and
+serve to determine, confirm, and illustrate the true and adæquate cause of
+each; and upon the whole, I find much reason to think, that the true cause
+of all these _Phænomena_ is from the _inflection_, or _multiplicate
+refraction_ of those Rays of light within the body of the _Atmosphere_, and
+that it does not proceed from a _refraction_ caus'd by any terminating
+_superficies_ of the Air above, nor from any such exactly defin'd
+_superficies_ within the body of the _Atmosphere_.
+
+This Conclusion is grounded upon these two Propositions:
+
+First, that a _medium_, whose parts are unequally _dense_, and mov'd by
+various motions and transpositions as to one another, will produce all
+these visible effects upon the Rays of light, without any other
+_coefficient_ cause.
+
+Secondly, that there is in the Air or _Atmosphere_ such a variety in the
+constituent parts of it, both as to their _density_ and _rarity_, and as to
+their divers mutations and positions one to another.
+
+By _Density_ and _Rarity_, I understand a property of a transparent body,
+that does either more or less refract a Ray of light (coming obliquely upon
+its superficies out of a third _medium_) toward its perpendicular: As I
+call Glass a more dense body then Water, and Water a more rare body then
+Glass, because of the refractions (more or less deflecting towards the
+perpendicular) that are made in them, of a Ray of light out of the Air that
+has the same inclination upon either of their superficies.
+
+So as to the business of Refraction, spirit of Wine is a more _dense_ body
+then Water, it having been found by an accurate Instrument that measures
+the angles of Refractions to Minutes that for the same refracted angle of
+30°.00'. in both those _Mediums_, the angle of incidence in Water was but
+41°.35'. but the angle of the incidence in the trial with spirit of Wine
+was 42°.45'. But as to gravity, Water is a more _dense_ body then spirit of
+Wine, for the proportion of the same Water, to the same very well rectify'd
+spirit of Wine was, as 21. to 19.
+
+So as to Refraction, Water is more Dense then Ice; for I have found by a
+most certain Experiment, which I exhibited before divers illustrious
+Persons of the _Royal Society_, that the Refraction of Water was greater
+then that of Ice, though some considerable Authors have affirm'd the
+contrary, and though the Ice be a very hard, and the Water a very fluid
+body.
+
+That the former of the two preceding Propositions is true, may be
+manifested by several Experiments; As first, if you take any two liquors
+differing from one another in density, but yet such as will readily mix: as
+Salt Water, or Brine, & Fresh; almost any kind of Salt dissolv'd in Water,
+and filtrated, so that it be cleer, spirit of Wine and Water; nay, spirit
+of Wine, and spirit of Wine, one more highly rectify'd then the other, and
+very many other liquors; if (I say) you take any two of these liquors, and
+mixing them in a Glass Viol, against one side of which you have fix'd or
+glued a small round piece of Paper, and shaking them well together (so that
+the parts of them may be somewhat disturb'd and move up and down) you
+endeavour to see that round piece of Paper through the body of the liquors,
+you shall plainly perceive the Figure to wave, and to be indented much
+after the same manner as the limb of the Sun through a _Telescope_ seems to
+be, save onely that the mutations here, are much quicker. And if, in steed
+of this bigger Circle, you take a very small spot, and fasten and view it
+as the former, you will find it to appear much like the twinkling of the
+Starrs, though much quicker: which two _Phænomena_, (for I shall take
+notice of no more at present, though I could instance in multitudes of
+others) must necessarily be caus'd by an _inflection_ of the Rays within
+the terminating superficies of the compounded _medium_, since the surfaces
+of the transparent body through which the Rays pass to the eye, are not at
+all altered or chang'd.
+
+This _inflection_ (if I may so call it) I imagine to be nothing else, but a
+_multiplicate refraction_, caused by the unequal _density_ of the
+constituent parts of the _medium_, whereby the motion, action or progress
+of the Ray of light is hindred from proceeding in a streight line, and
+_inflected_ or _deflected_ by a _curve_. Now, that it is a _curve_ line is
+manifest by this Experiment: I took a Box, such as ADGE, in the first
+_Figure_ of the 37. _Scheme_, whose sides ABCD, and EFGH, were made of two
+smooth flat plates of Glass, then filling it half full with a very strong
+solution of Salt, I filled the other half with very fair fresh water, then
+exposing the opacous side, DHGC, to the Sun, I observ'd both the
+_refraction_ and _inflection_ of the Sun beams, ID & KH, and marking as
+exactly as I could, the points, P, N, O, M, by which the Ray, KH, passed
+through the compounded _medium_, I found them to be in a _curve_ line; for
+the parts of the _medium_ being continually more dense the neerer they were
+to the bottom, the Ray _pf_ was continually more and more deflected
+downwards from the streight line.
+
+This Inflection may be mechanically explained, either by Monsieur _Des
+Cartes_ principles by conceiving the Globuls of the third Element to find
+less and less resistance against that side of them which is downwards, or
+by a way, which I have further explicated in the Inquisition about Colours,
+to be from an obliquation of the pulse of light, whence the under part is
+continually promoted, and consequently refracted towards the perpendicular,
+which cuts the Orbs at right angles. What the particular Figure of the
+_Curve line_, describ'd by this way of light, is, I shall not now stand to
+examine, especially since there may be so many sorts of it as there may be
+varieties of the Positions of the _intermediat_ degrees of _density_ and
+_rarity_ between the bottom and the top of the inflecting Medium.
+
+I could produce many more Examples and Experiments, to illustrate and prove
+this first Proposition, _viz._ that there is such a constitution of some
+bodies as will cause inflection. As not to mention those I have observ'd in
+_Horn_, _Tortoise-Shell_, _transparent Gums_, and _resinous Substances_:
+The _veins_ of Glass, nay, of melted _Crystal_, found, and much complained
+of by Glass-grinders, and others, might sufficiently demonstrate the truth
+of it to any diligent Observator.
+
+But that, I presume, I have by this Example given proof sufficient (_viz.
+ocular demonstration_) to evince, that there is such a modulation, or
+bending of the rayes of light, as I have call'd _inflection_, differing
+both from _reflection_, and _refraction_ (since they are both made in the
+superficies, this only in the middle); and likewise, that this is able or
+sufficient to produce the effects I have ascribed to it.
+
+It remains therefore to shew, that there is such a property in the Air, and
+that it is sufficient to produce all the above mentioned _Phænomena_, and
+therefore may be the principal, if not the only cause of them.
+
+First, That there is such a property, may be proved from this, that the
+parts of the Air are some of them more condens'd, others more rarified,
+either by the differing heat, or differing pressure it sustains, or by the
+somewhat heterogeneous vapours interspers'd through it. For as the Air is
+more or less rarified, so does it more or less refract a ray of light (that
+comes out of a denser medium) from the perpendicular. This you may find
+true, if you make tryal of this Experiment.
+
+Take a small Glass-bubble, made in the form of that in the second Figure of
+the 37. _Scheme_, and by heating the Glass very hot, and thereby very much
+rarifying the included Air, or, which is better, by rarifying a small
+quantity of water, included in it, into vapours, which will expel the most
+part, if not all the Air, and then sealing up the small neck of it, and
+letting it cool, you may find, if you place it in a convenient Instrument,
+that there will be a manifest difference, as to the refraction.
+
+As if in this second Figure you suppose A to represent a small sight or
+hole, through which the eye looks upon an object, as C, through the
+Glass-bubble B, and the second sight L; all which remain exactly fixt in
+their several places, the object C being so cized and placed, that it may
+just seem to touch the upper and under edge of the hole L: and so all of it
+be seen through the small Glass-ball of rarified Air; then by breaking off
+the small seal'd neck of the Bubble (without at all stirring the sights,
+object, or glass) and admitting the external Air, you will find your self
+unable to see the utmost ends of the object; but the terminating rayes AE
+and AD (which were before refracted to G and F by the rarified Air) will
+proceed almost directly to I and H; which alteration of the rayes (seeing
+there is no other alteration made in the Organ by which the Experiment is
+tryed, save only the admission, or exclusion of the condens'd Air) must
+necessarily be caused by the variation of the _medium_ contain'd in the
+Glass B; the greatest difficulty in the making of which Experiment, is from
+the uneven surfaces of the bubble, which will represent an uneven image of
+the object.
+
+Now, that there is such a difference of the upper and under parts of the
+Air is clear enough evinc'd from the late improvement of the _Torricellian_
+Experiment, which has been tryed at the tops and feet of Mountains; and may
+be further illustrated, and inquired into, by a means, which some whiles
+since I thought of, and us'd, for the finding by what degrees the Air
+passes from such a degree of Density to such a degree of Rarity. And
+another, for the finding what pressure was requisite to make it pass from
+such a degree of Rarefaction to a determinate Density: Which Experiments,
+because they may be useful to illustrate the present Inquiry, I shall
+briefly describe.
+
+[16] I took then a small Glass-pipe AB, about the bigness of a Swans quill,
+and about four foot long, which was very equally drawn, so that, as far as
+I could perceive, no one part was bigger then another: This Tube (being
+open at both ends) I fitted into another small Tube DE, that had a small
+bore just big enough to contain the small Pipe, and this was seal'd up at
+one, and open at the other, end; about which open end I fastned a small
+wooden box C with cement, so that filling the bigger Tube, and part of the
+box, with Quicksilver, I could thrust the smaller Tube into it, till it
+were all covered with the Quicksilver: Having thus done, I fastned my
+bigger Tube against the side of a wall, that it might stand the steadier,
+and plunging the small Tube cleer under the _Mercury_ in the box, I stopt
+the upper end of it very fast with cement, then lifting up the small Tube,
+I drew it up by a small pully, and a string that I had fastned to the top
+of the Room, and found the height of the _Mercurial Cylinder_ to be about
+twenty nine inches.
+
+Then letting down the Tube again, I opened the top, and then thrust down
+the small Tube, till I perceived the Quicksilver to rise within it to a
+mark that I had plac'd just an inch from the top; and immediately clapping
+on a small piece of cement that I had kept warm, I with a hot Iron seal'd
+up the top very fast, then letting it cool (that both the cement might grow
+hard, and more especially, that the Air might come to its temper, natural
+for the Day I try'd the Experiment in) I observ'd diligently, and found the
+included Air to be exactly an Inch.
+
+Here you are to take notice, that after the Air is seal'd up, the top of
+the Tube is not to be elevated above the superficies of the Quicksilver in
+the box, till the surface of that within the Tube be equal to it, for the
+Quicksilver (as I have elsewhere prov'd) being more heterogeneous to the
+Glass then the Air, will not naturally rise up so high within the small
+Pipe, as the superficies of the _Mercury_ in the box, and therefore you are
+to observe, how much below the outward superficies of the _Mercury_ in the
+box, that of the same in the Tube does stand, when the top being open, free
+ingress is admitted to the outward Air.
+
+Having thus done, I permitted the _Cylinder_, or small Pipe, to rise out of
+the box, till I found the surface of the Quicksilver in the Pipe to be two
+inches above that in the box, and found the Air to have expanded it self
+but one sixteenth part of an inch; then drawing up the small pipe, till I
+found the height of the Quicksilver within to be four inches above that
+without, I observed the Air to be expanded only 1/7 of an inch more then it
+was at first, and to take up the room of 1-1/7 inch: then I raised the Tube
+till the Cylinder was six inches high, and found the Air to take up 1-2/9
+inches of room in the Pipe; then to 8, 10, 12. &c. the expansion of the Air
+that I found to each of which Cylinders are set down in the following
+Table; where the first row signifies the height of the _Mercurial
+Cylinder_; the next, the expansion of the Air; the third, the pressure of
+the _Atmosphere_, or the highest _Cylinder_ of _Mercury_, which was then
+neer thirty inches: The last signifies the force of the Air so expanded,
+which is found by substracting the first row of numbers out of the third;
+for having found, that the outward Air would then keep up the Quicksilver
+to thirty inches, look whatever of that height is wanting must be
+attributed to the Elater of the Air depressing. And therefore having the
+Expansion in the second row, and the height of the subjacent _Cylinder_ of
+_Mercury_ in the first, and the greatest height of the _Cylinder_ of
+_Mercury_, which of it self counterballances the whole pressure of the
+_Atmosphere_; by substracting the numbers of the first row out of the
+numbers of the third, you will have the measure of the _Cylinders_ so
+deprest, and consequently the force of the Air, in the several Expansions,
+registred.
+
+  The height of the     The Expansion   The height of   The strength
+  Cylinder of Mercury,  of the Air.     the Mercury     of the Elater
+  that, together with                   that counter-   of the expanded
+  the Elater of the                     ballanc'd the   Air.
+  included Air,                         Atmosphere.
+  ballanced the
+  pressure of the
+  Atmosphere.
+   ----------            ----------      ----------      ----------
+      00                    01               30              30
+      02                    01-1/16          30              28
+      04                    01-1/7           30              26
+      06                    01-2/9           30              24
+      08                    01-1/3           30              22
+      10                    01-1/2           30              20
+      12                    01-2/3           30              18
+      14                    01-5/6           30              16
+      16                    02-2/27          30              14
+      18                    02-4/9           30              12
+      20                    03               30              10
+      22                    03-7/9           30               8
+      24                    05-7/18          30               6
+      25                    06-2/3           30               5
+      26                    08-1/2           30               4
+      26-1/4                09-1/2           30               3-3/4
+      26-1/2                10-3/4           30               3-1/2
+      26-3/4                13               30               3-1/4
+      27                    15-1/2           30               3
+
+I had several other Tables of my Observations, and Calculations, which I
+then made; but it being above a twelve month since I made them; and by that
+means having forgot many circumstances and particulars, I was resolved to
+make them over once again, which I did _August_ the second 1661. with the
+very same Tube which I used the year before, when I first made the
+Experiment (for it being a very good one, I had carefully preserv'd it:)
+And after having tryed it over and over again; and being not well satisfied
+of some particulars, I, at last, having put all things in very good order,
+and being as attentive, and observant, as possibly I could, of every
+circumstance requisite to be taken notice of, did register my several
+Observations in this following Table. In the making of which, I did not
+exactly follow the method that I had used at first; but, having lately
+heard of Mr. _Townly_'s _Hypothesis_, I shap'd my course in such sort, as
+would be most convenient for the examination of that _Hypothesis_; the
+event of which you have in the latter part of the last Table.
+
+The other Experiment was, to find what degrees of force were requisite to
+compress, or condense, the Air into such or such a bulk.
+
+The manner of proceeding therein was this: I took a Tube about five foot
+long, one of whose ends was sealed up, and bended in the form of a
+_Syphon_, much like that represented in the fourth Figure of the 37.
+_Scheme_, one side whereof AD, that was open at A, was about fifty inches
+long, the other side BC, shut at B, was not much above seven inches long,
+then placing it exactly perpendicular, I pour'd in a little Quicksilver,
+and found that the Air BC was 6-7/8 inches, or very near to seven; then
+pouring in Quicksilver at the longer Tube, I continued filling of it till
+the Air in the shorter part of it was contracted into half the former
+dimensions, and found the height exactly nine and twenty inches; and by
+making several other tryals, in several other degrees of condensation of
+the Air, I found them exactly answer the former _Hypothesis_.
+
+But having (by reason it was a good while since I first made) forgotten
+many particulars, and being much unsatisfied in others, I made the
+Experiment over again, and, from the several tryals, collected the former
+part of the following Table: Where in the row next the left hand 24.
+signifies the dimensions of the Air, sustaining only the pressure of the
+_Atmosphere_, which at that time was equal to a _Cylinder_ of _Mercury_ of
+nine and twenty inches: The next Figure above it (20) was the dimensions of
+the Air induring the first compression, made by a _Cylinder_ of _Mercury_
+5-3/16 high, to which the pressure of the _Atmosphere_ nine and twenty
+inches being added, the elastick strength of the Air so comprest will be
+found 34-3/16, &c.
+
+_A Table of the Elastick power of the Air, both Experimentally and
+Hypothetically calculated, according to its various Dimensions._
+
+
+  The dimensions   The height    The Mercurial  The sum or  What they
+  of the included  of the        Cylinder       difference  ought to
+  Air.             Mercurial     added, or      of these    be according
+                   Cylinder      taken from     two         to the
+                   counter-      the former.    Cylinders.  Hypothesis.
+                   pois'd
+                   by the
+                   Atmosphere.
+   ----------      ----------     ----------     ----------  ----------
+       12             29      +     29         =   58          58
+       13             29      +     24-11/16   =   53-11/16    53-7/13
+       14             29      +     20-3/16    =   49-3/16     49-5/7
+       16             29      +     14         =   43          43-1/2
+       18             29      +      9-1/8     =   38-1/8      38-2/3
+       20             29      +      5-3/16    =   34-3/16     34-4/5
+       24             29             0         =   29          29
+       48             29      -     14-5/8     =   14-3/8      14-1/2
+       96             29      -     22-1/8     =    6-7/8       7-2/8
+      192             29      -     25-5/8     =    3-3/8       3-5/8
+      384             29      -     27-2/8     =    1-6/8       1-7/16
+      576             29      -     27-7/8     =    1-1/8       1-5/24
+      768             29      -     28-1/8     =    0-7/8       0-[7-1/4]/8
+      960             29      -     28-3/8     =    0-5/8       0-[5-4/5]/8
+     1152             29      -     28-7/16    =    0-9/16      0-10/16
+
+From which Experiments, I think, we may safely conclude, that the Elater of
+the Air is reciprocal to its extension, or at least very neer. So that to
+apply it to our present purpose (which was indeed the chief cause of
+inventing these wayes of tryal) we will suppose a _Cylinder_ indefinitely
+extended upwards, [I say a _Cylinder_, not a piece of a _Cone_, because, as
+I may elsewhere shew in the Explication of Gravity, that _triplicate_
+proportion of the shels of a Sphere, to their respective diameters, I
+suppose to be removed in this case by the decrease of the power of Gravity]
+and the pressure of the Air at the bottom of this _Cylinder_ to be strong
+enough to keep up a _Cylinder_ of _Mercury_ of thirty inches: Now because
+by the most accurate tryals of the most illustrious and incomparable Mr.
+_Boyle_, published in his deservedly famous Pneumatick Book, the weight of
+Quicksilver, to that of the Air here below, is found neer about as fourteen
+thousand to one: If we suppose the parts of the _Cylinder_ of the
+_Atmosphere_ to be every where of an equal density, we shall (as he there
+deduces) find it extended to the height of thirty five thousand feet, or
+seven miles: But because by these Experiments we have somewhat confirm'd
+the hypothesis of the reciprocal proportion of the Elaters to the
+Extensions we shall find, that by supposing this _Cylinder_ of the
+_Atmosphere_ divided into a thousand parts, each of which being equivalent
+to thirty five feet, or seven geometrical paces, that is, each of these
+divisions containing as much Air as is suppos'd in a _Cylinder_ neer the
+earth of equal diameter, and thirty five foot high, we shall find the
+lowermost to press against the surface of the Earth with the whole weight
+of the above mentioned thousand parts; the pressure of the bottom of the
+second against the top of the first to be 1000 - 1 = 999. of the third
+against the second to be 1000 - 2 = 998. of the fourth against the third to
+be 1000 - 3 = 997. of the uppermost against the 999. or that next below it,
+to be 1000 - 999 = 1. so that the extension of the lowermost next the
+Earth, will be to the extension of the next below the uppermost, as 1. to
+999. for as the pressure sustained by the 999. is to the pressure sustain'd
+by the first, so is the extension of the first to the extension of the 999.
+so that, from this hypothetical calculation, we shall find the Air to be
+indefinitely extended: For if we suppose the whole thickness of the Air to
+be divided, as I just now instanced, into a thousand parts, and each of
+those under differing Dimensions, or Altitudes, to contain an equall
+quantity of Air, we shall find, that the first _Cylinder_, whose Base is
+supposed to lean on the Earth, will be found to be extended 35-35/999 foot;
+the second equal Division, or _Cylinder_, whose _basis_ is supposed to lean
+on the top of the first, shall have its top extended higher by 35-70/998
+the third 35-105/997 the fourth 35-140/996 and so onward, each equal
+quantity of Air having its dimensions measured by 35. and some additional
+number exprest alwayes in the manner of a fraction, whose numerator is
+alway the number of the place multipli'd by 35. and whose denominator is
+alwayes the pressure of the _Atmosphere_ sustain'd by that part, so that by
+this means we may easily calculate the height of 999. divisions of those
+1000. divisions, I suppos'd; whereas the uppermost may extend it self more
+then as high again, nay, perhaps indefinitely, or beyond the Moon; for the
+Elaters and Expansions being in reciprocal proportions, since we cannot yet
+find the _plus ultra_, beyond which the Air will not expand it self, we
+cannot determine the height of the Air: for since, as we have shewn, the
+proportion will be alway as the pressure sustain'd by any part is to 35. so
+1000. to the expansion of that part; the multiplication or product
+therefore of the pressure, and expansion, that is, of the two extream
+proportionals, being alwayes equal to the product of the means, or 35000.
+it follows, since that Rectangle or Product may be made up of the
+multiplication of infinite diversities of numbers, that the height of the
+Air is also indefinite; for since (as far as I have yet been able to try)
+the Air seems capable of an indefinite Expansion, the pressure may be
+decreased in _infinitum_, and consequently its expansion upwards indefinite
+also.
+
+There being therefore such a difference of density, and no Experiment yet
+known to prove a _Saltus_, or skipping from one degree of rarity to another
+much differing from it, that is, that an upper part of the Air should so
+much differ from that immediately _subjacent_ to it, as to make a distinct
+superficies, such as we observe between the Air and Water, &c. But it being
+more likely, that there is a continual increase of rarity in the parts of
+the Air, the further they are removed from the surface of the Earth: It
+will hence necessarily follow, that (as in the Experiment of the salt and
+fresh Water) the ray of Light passing obliquely through the Air also, which
+is of very different density, will be continually, and infinitely
+inflected, or bended, from a streight, or direct motion.
+
+This granted, the reason of all the above recited _Phænomena_, concerning
+the appearance of the Celestial Bodies, will very easily be deduced. As,
+
+First, The redness of the Sun, Moon, and Stars, will be found to be caused
+by the inflection of the rays within the _Atmosphere_. That it is not
+really in or near the luminous bodies, will, I suppose, be very easily
+granted, seeing that this redness is observable in several places differing
+in Longitude, to be at the same time different, the setting and rising Sun
+of all parts being for the most part red:
+
+And secondly, That it is not meerly the colour of the Air interpos'd, will,
+I suppose, without much more difficulty be yielded, seeing that we may
+observe a very great _interstitium_ of Air betwixt the Object, and the Eye,
+makes it appear of a dead blew, far enough differing from a red, or yellow.
+
+But thirdly, That it proceeds from the refraction, or inflection, of the
+rays by the _Atmosphere_, this following Experiment will, I suppose,
+sufficiently manifest.
+
+Take a sphærical Crystalline Viol, such as is describ'd in the fifth Figure
+ABCD, and, having fill'd it with pure clear Water, expose it to the Sun
+beams; then taking a piece of very fine _Venice_ Paper, apply it against
+that side of the Globe that is opposite to the Sun, as against the side BC,
+and you shall perceive a bright red Ring to appear, caus'd by the
+refraction of the Rays, AAAA, which is made by the Globe; in which
+Experiment, if the Glass and Water be very cleer, so that there be no Sands
+nor bubbles in the Glass, nor dirt in the Water, you shall not perceive any
+appearance of any other colour. To apply which Experiment, we may imagine
+the _Atmosphere_ to be a great transparent Globe, which being of a
+substance more dense then the other, or (which comes to the same) that has
+its parts more dense towards the middle, the Sun beams that are tangents,
+or next within the tangents of this Globe, will be refracted or inflected
+from their direct passage towards the center of the Globe, whence,
+according to the laws of refractions made in a triangular _Prism_, and the
+generation of colour set down in the description of Muscovi-glass there
+must necessarily appear a red colour in the _transitus_ or passage of those
+tangent Rays. To make this more plain, we will suppose (in the sixth
+_Figure_) ABCD, to represent the Globe of the _Atmosphere_, EFGH to
+represent the opacous Globe of the Earth, lying in the midst of it, neer to
+which, the parts of the Air, sustaining a very great pressure, are thereby
+very much condens'd, from whence those Rays that are by inflection made
+tangents to the Globe of the Earth, and those without them, that pass
+through the more condens'd part of the _Atmosphere_, as suppose between A
+and E, are by reason of the inequality of the _medium_, inflected towards
+the center, whereby there must necessarily be generated a red colour, as is
+more plainly shewn in the former cited place; hence whatsoever opacous
+bodies (as vapours, or the like) shall chance to be elevated into those
+parts, will reflect a red towards the eye; and therefore those evenings and
+mornings appear reddest, that have the most store of vapours and halituous
+substances exhaled to a convenient distance from the Earth; for thereby the
+inflection is made the greater, and thereby the colour also the more
+intense; and several of those exhalations being opacous, reflect several of
+those Rays, which, through an _Homogeneous_ transparent _medium_ would pass
+unseen; and therefore we see, that when there chances to be any clouds
+situated in those Regions they reflect a strong and vivid red. Now, though
+one great cause of the redness may be this inflection, yet I cannot wholly
+exclude the colour of the vapours themselves, which may have something of
+redness in them, they being partly nitrous; and partly fuliginous; both
+which steams tinge the Rays that pass through them, as is made evident by
+looking at bodies through the fumes of _Aqua fortis_ or spirit of _Nitre_
+[as the newly mentioned Illustrious Person has demonstrated] and also
+through the smoak of a Fire or Chimney.
+
+Having therefore made it probable at least, that the morning and evening
+redness may partly proceed from this inflection or refraction of the Rays,
+we shall next shew how the Oval Figure will be likewise easily deduced.
+
+Suppose we therefore, EFGH in the sixth _Figure_ of the 37. _Scheme_, to
+represent the Earth; ABCD, the _Atmosphere_; EI, and EL, two Rays coming
+from the Sun, the one from the upper, the other from the neather Limb,
+these Rays, being by the _Atmosphere_ inflected, appear to the eye at E, as
+if they had come from the points, N and O; and because the Ray L has a
+greater inclination upon the inequality of the _Atmosphere_ then I,
+therefore must it suffer a greater inflection, and consequently be further
+elevated above its true place, then the Ray I, which has a less
+inclination, will be elevated above its true place; whence it will follow,
+that the lower side appearing neerer the upper then really it is, and the
+two _lateral_ sides, _viz._ the right and left side, suffering no sensible
+alteration from the inflection, at least what it does suffer, does rather
+increase the visible Diameter then diminish it, as I shall shew by and by,
+the Figure of the luminous body must necessarily appear somewhat
+_Elliptical_.
+
+This will be more plain, if in the seventh _Figure_ of the 37. _Scheme_ we
+suppose AB to represent the sensible Horizon; CDEF, the body of the Sun
+really below it; GHIK, the same appearing above it, elevated by the
+inflection of the _Atmosphere_: For if, according to the best observation,
+we make the visible Diameter of the Sun to be about three or four and
+thirty minutes, and the Horizontal refraction according to _Ticho_ be
+thereabout, or somewhat more, the lower limb of the Sun E, will be elevated
+to I; but because, by his account, the point C will be elevated but 29.
+minutes, as having not so great an inclination upon the inequality of the
+Air, therefore IG, which will be the apparent refracted perpendicular
+Diameter of the Sun, will be less then CG, which is but 29. minutes, and
+consequently six or seven minutes shorter then the unrefracted apparent
+Diameter. The parts, D and F, will be likewise elevated to H and K, whose
+refraction, by reason of its inclination, will be bigger then that of the
+point C, though less then that of E; therefore will the semidiameter IL, be
+shorter then LG, and consequently the under side of the appearing Sun more
+flat then the upper.
+
+Now, because the Rays from the right and left sides of the Sun, &c. have
+been observ'd by _Ricciolo_ and _Grimaldus_, to appear more distant one
+from another then really they are, though (by very many Observations that I
+have made for that purpose, with a very good _Telescope_, fitted with a
+divided Ruler) I could never perceive any great alteration, yet there being
+really some, it will not be amiss, to shew that this also proceeds from the
+refraction or inflection of the _Atmosphere_; and this will be manifest, if
+we consider the _Atmosphere_ as a transparent Globe, or at least a
+transparent shell, encompassing an opacous Globe, which, being more dense
+then the _medium_ encompassing it, refracts or inflects all the entring
+parallel Rays into a point or focus, so that wheresoever the Observator is
+plac'd within the _Atmosphere_, between the focus and the luminous body,
+the _lateral_ Rays must necessarily be more converg'd towards his eye by
+the refraction or inflection, then they would have been without it; and
+therefore the Horizontal Diameter of the luminous body must necessarily be
+augmented.
+
+This might be more plainly manifest to the eye by the sixth _Figure_; but
+because it would be somwhat tedious, and the thing being obvious enough to
+be imagin'd by any one that attentively considers it, I shall rather omit
+it, and proceed to shew, that the mass of Air neer the surface of the
+Earth, consists, or is made up, of parcels, which do very much differ from
+one another in point of density and rarity; and consequently the Rays of
+light that pass through them will be variously inflected, here one way, and
+there another, according as they pass so or so through those differing
+parts; and those parts being always in motion, either upwards or downwards,
+or to the right or left, or in some way compounded of these, they do by
+this their motion inflect the Rays, now this way, and presently that way.
+
+This irregular, unequal and unconstant inflection of the Rays of light, is
+the reason why the limb of the _Sun_, _Moon_, _Jupiter_, _Saturn_, _Mars_,
+and _Venus_, appear to wave or dance; and why the body of the Starrs appear
+to tremulate or twinkle, their bodies, by this means, being sometimes
+magnify'd, and sometimes diminished; sometimes elevated, otherwhiles
+depress'd; now thrown to the right hand, and then to the left.
+
+And that there is such a property or unequal distribution of parts, is
+manifest from the various degrees of heat and cold that are found in the
+Air; from whence will follow a differing density and rarity, both as to
+quantity and refraction; and likewise from the vapours that are interpos'd,
+(which, by the way, I imagine, as to refraction or inflection, to do the
+same thing, as if they were rarify'd Air; and that those vapours that
+ascend, are both lighter, and less dense, then the ambient Air which boys
+them up; and that those which descend, are heavier and more dense) The
+first of these may be found true, if you take a good thick piece of Glass,
+and heating it pretty hot in the fire, lay it upon such another piece of
+Glass, or hang it in the open Air by a piece of Wire, then looking upon
+some far distant Object (such as a Steeple or Tree) so as the Rays from
+that Object pass directly over the Glass before they enter your eye, you
+shall find such a tremulation and wavering of the remote Object, as will
+very much offend your eye: The like tremulous motion you may observe to be
+caus'd by the ascending steams of Water, and the like. Now, from the first
+of these it is manifest, that from the rarifaction of the parts of the Air,
+by heat, there is caus'd a differing refraction, and from the ascension of
+the more rarify'd parts of the Air, which are thrust up by the colder, and
+therefore more condens'd and heavie, is caus'd an undulation or wavering of
+the Object; for I think, that there are very few will grant, that Glass, by
+as gentle a heat as may be endur'd by ones hand, should send forth any of
+its parts in steams or vapours, which does not seem to be much wasted by
+that violent fire of the green Glass-house; but, if yet it be doubted, let
+Experiment be further made with that body that is accounted, by Chymists
+and others, the most ponderous and fix'd in the world; for by heating of a
+piece of Gold, and proceeding in the same manner, you may find the same
+effects.
+
+This trembling and shaking of the Rays, is more sensibly caus'd by an
+actual flame, or quick fire, or anything else heated glowing hot; as by a
+Candle, live Coal, red-hot Iron, or a piece of Silver, and the like: the
+same also appears very conspicuous, if you look at an Object betwixt which
+and your eye, the rising smoak of some Chimney is interpos'd; which brings
+into my mind what I had once the opportunity to observe, which was, the Sun
+rising to my eye just over a Chimney that sent forth a copious steam of
+smoak; and taking a short _Telescope_, which I had then by me, I observ'd
+the body of the Sun, though it was but just peep'd above the Horizon, to
+have its underside, not onely flatted, and press'd inward, as it usually is
+when neer the Earth; but to appear more protuberant downwards then if it
+had suffered no refraction at all; and besides all this, the whole body of
+the Sun appear'd to tremble or dance, and the edges or limb to be very
+ragged or indented, undulating or waving, much in the manner of a flag in
+the Wind.
+
+This I have likewise often observ'd in a hot Sunshiny Summer's day, that
+looking on an Object over a hot stone, or dry hot earth, I have found the
+Object to be undulated or shaken, much after the same manner. And if you
+look upon any remote Object through a _Telescope_ (in a hot Summer's day
+especially) you shall find it likewise to appear tremulous. And further, if
+there chance to blow any wind, or that the air between you and the Object
+be in a motion or current, whereby the parts of it, both rarify'd and
+condens'd, are swiftly remov'd towards the right or left, if then you
+observe the Horizontal ridge of a Hill far distant, through a very good
+_Telescope_, you shall find it to wave much like the Sea, and those waves
+will appear to pass the same way with the wind.
+
+From which, and many other Experiments, 'tis cleer that the lower Region of
+the Air, especially that part of it which lieth neerest to the Earth, has,
+for the most part, its constituent parcels variously agitated, either by
+heat or winds, by the first of which, some of them are made more rare, and
+so suffer a less refraction; others are interwoven, either with ascending
+or descending vapours; the former of which being more light, and so more
+rarify'd, have likewise a less refraction; the latter being more heavie,
+and consequently more dense, have a greater.
+
+Now, because that heat and cold are equally diffus'd every way; and that
+the further it is spread, the weaker it grows; hence it will follow, that
+the most part of the under Region of the Air will be made up of several
+kinds of _lentes_, some whereof will have the properties of _Convex_,
+others of _Concave_ _glasses_, which, that I may the more intelligibly make
+out, we will suppose in the eighth _Figure_ of the 37. _Scheme_, that A
+represents an ascending vapour, which, by reason of its being somewhat
+_Heterogeneous_ to the ambient Air, is thereby thrust into a kind of
+Globular form, not any where terminated, but gradually finished, that is,
+it is most rarify'd in the middle about A. somewhat more condens'd about
+BB, more then that about CC; yet further, about DD, almost of the same
+density with the ambient Air about EE;, and lastly, inclosed with the more
+dense Air FF, so that from A, to FF, there is a continual increase of
+density. The reason of which will be manifest, if we consider the rising
+vapour to be much warmer then the ambient heavie Air; for by the coldness
+of the ambient Air, the shell EE will be more refrigerated then DD, and
+that then CC, which will be yet more then BB, and that more then A; so that
+from F to A, there is a continual increase of heat, and consequently of
+rarity; from whence it will necessarily follow, that the Rays of light will
+be inflected or refracted in it, in the same manner as they would be in a
+_Concave-glase_; for the Rays _GKI_, _GKI_ will be inflected by _GKH_,
+_GKH_, which will easily follow from what I before explained concerning the
+inflection of the _Atmosphere_.
+
+On the other side, a descending vapour, or any part of the air included by
+an ascending vapour, will exhibit the same effects with a _Convex lens_;
+for, if we suppose, in the former Figure, the quite contrary constitution
+to that last describ'd; that is, the ambient Air FF being hotter then any
+part of that matter within any circle, therefore the coldest part must
+necessarily be A, as being farthest remov'd from the heat, all the
+intermediate spaces will be gradually discriminated by the continuall
+mixture of heat and cold, so that it will be hotter at EE, then DD, in DD
+then CC, in CC then BB, and in BB then A. From which, a like refraction and
+condensation will follow, and consequently a lesser or greater refraction,
+so that every included part will refract more then the including, by which
+means the Rays, GKI, GKI, coming from a Starr, or some remote Object, are
+so inflected, that they will again concurr and meet, in the point M. By the
+interposition therefore of this desending vapour the visible body of the
+Star, or other Object, is very much augmented, as by the former it was
+diminished.
+
+From the quick consecutions of these two, one after another, between the
+Object and your eye, caused by their motion upwards or downwards,
+proceeding from their levity or gravity, or to the right or left,
+proceeding from the wind, a Starr may appear, now bigger, now less, then
+really it would otherwise without them; and this is that property of a
+Starr, which is commonly call'd twinkling, or scintillation.
+
+The reason why a Star will now appear of one colour, now of another, which
+for the most part happens when 'tis neer the Horizon, may very easily be
+deduc'd from its appearing now in the middle of the vapour, other whiles
+neer the edge; for if you look against the body of a Starr with a
+_Telescope_ that has a pretty deep _Convex_ Eye-glass, and so order it,
+that the Star may appear sometimes in one place, and sometimes in another
+of it; you may perceive this or that particular colour to be predominant in
+the apparent Figure of the Starr, according as it is more or less remote
+from the middle of the _Lens_. This I had here further explain'd, but that
+it does more properly belong to another place.
+
+I shall therefore onely add some few Queries, which the consideration of
+these particulars hinted, and so finish this Section.
+
+And the first I shall propound is, Whether there may not be made an
+artificial transparent body of an exact Globular Figure that shall so
+inflect or refract all the Rays, that, coming from one point, fall upon any
+_Hemisphere_ of it; that every one of them may meet on the opposite side,
+and cross one another exactly in a point; and that it may do the like also
+with all the Rays that, coming from a _lateral_ point, fall upon any other
+_Hemisphere_; for if so, there were to be hoped a perfection of
+_Dioptricks_, and a transmigration into heaven, even whil'st we remain here
+upon earth in the flesh, and a descending or penetrating into the center
+and innermost recesses of the earth, and all earthly bodies; nay, it would
+open not onely a cranney, but a large window (as I may so speak) into the
+Shop of Nature, whereby we might be enabled to see both the tools and
+operators, and the very manner of the operation it self of Nature; this,
+could it be effected, would as farr surpass all other kind of perspectives
+as the vast extent of Heaven does the small point of the Earth, which
+distance it would immediately remove, and unite them, as 'twere, into one,
+at least, that there should appear no more distance between them then the
+length of the Tube, into the ends of which these Glasses should be
+inserted: Now, whether this may not be effected with parcels of Glass of
+several densities, I have sometimes proceeded so farr as to doubt (though
+in truth, as to the general, I have wholly despair'd of it) for I have
+often observ'd in Optical Glasses a very great variety of the parts, which
+are commonly called Veins; nay, some of them round enough (for they are for
+the most part, drawn out into firings) to constitute a kind of _lens_.
+
+This I should further proceed to hope, had any one been so inquisitive as
+to have found out the way of making any transparent body, either more dense
+or more rare, for then it might be possible to compose a Globule that
+should be more dense in the middle of it, then in any other part, and to
+compose the whole bulk, so as that there should be a continual gradual
+transition from one degree of density to another; such as should be found
+requisite for the desired inflection of the _transmigrating_ Rays; but of
+this enough at present, because I may say more of it when I set down my own
+Trials concerning the melioration of _Dioptricks_, where I shall enumerate
+with how many several substances I have made both _Microscopes_, and
+_Telescopes_, and by what and how many, ways: Let such as have leisure and
+opportunity farther consider it.
+
+The next Quæry shall be, whether by the same collection of a more dense
+body then the other, or at least, of the denser part of the other, there
+might not be imagin'd a reason of the apparition of some new fix'd Stars,
+as those in the Swan, _Cassiope's Charr_, _Serpentarius_, _Piscis_,
+_Cetus_, &c.
+
+Thirdly, Whether it be possible to define the height of the _Atmosphere_
+from this inflection of the Rays, or from the Quicksilver Experiment of the
+rarifaction or extension of the Air.
+
+Fourthly, Whether the disparity between the upper and under Air be not
+sometimes so great, as to make a reflecting superficies; I have had several
+Observations which seem to have proceeded from some such cause, but it
+would be too long to relate and examine them. An Experiment, also somewhat
+analogous to this, I have made with Salt-water and Fresh, which two
+liquors, in most Positions, seem'd the same, and not to be separated by any
+determinate superficies, which separating surface yet in some other
+Positions did plainly appear.
+
+And if so, Whether the reason of the equal bounding or _terminus_ of the
+under parts of the clouds may not proceed from this cause; whether,
+secondly, the Reason of the apparition of many Suns may not be found out,
+by considering how the Rays of the Sun may so be reflected, as to describe
+a pretty true Image of the body, as we find them from any regular
+Superficies. Whether also this may not be found to cause the apparition of
+some of those _Parelii_, of counterfeit Suns, which appear coloured, by
+refracting the Rays so, as to make the body of the Sun appear in quite
+another place then really it is. But of this more elsewhere.
+
+5. Whether the _Phænomena_ of the Clouds may not be made out by this
+diversity of density in the upper and under parts of the Air, by supposing
+the Air above them to be much lighter then they themselves are, and they
+themselves to be yet lighter then that which is subjacent to them, many of
+them seeming to be the same substance with the Cobwebs that fly in the Air
+after a Fog.
+
+Now that such a constitution of the Air and Clouds, if such there be, may
+be sufficient to perform this effect, may be confirm'd by this Experiment.
+
+Make as strong a Solution of Salt as you are able, then filling a Glass of
+some depth half full with it, fill the other half with fresh Water, and
+poyse a little Glass-bubble, so as that it may sink pretty quick in fresh
+Water, which take and put into the aforesaid Glass, and you shall find it
+to sink till it comes towards the middle, where it will remain fixt,
+without moving either upwards or downwards. And by a second Experiment, of
+poising such a bubble in water, whose upper part is warmer, and
+consequently lighter, then the under, which is colder and heavier; the
+manner of which follows in this next Quæry, which is,
+
+6. Whether the rarifaction and condensation of Water be not made after the
+same manner, as those effects are produc'd in the Air by heat; for I once
+pois'd a seal'd up Glass-bubble so exactly, that never so small an addition
+would make it sink, and as small a detraction make it swim, which suffering
+to rest in that Vessel of Water for some time, I alwayes found it about
+noon to be at the bottom of the Water, and at night, and in the morning, at
+the top: Imagining this to proceed from the Rarifaction of the Water,
+caus'd by the heat, I made tryal, and found most true; for I was able at
+any time, either to depress, or raise it, by heat and cold; for if I let
+the Pipe stand for some time in cold water, I could easily raise the Bubble
+from the bottom, whither I had a little afore detruded it, by putting the
+same Pipe into warm Water. And this way I have been able, for a very
+considerable time, to keep a Bubble so poys'd in the Water, as that it
+should remain in the middle, and neither sink, nor swim: For gently heating
+the upper part of the Pipe with a Candle, Coal, or hot Iron, till I
+perceived the Bubble begin to descend, then forbearing, I have observed it
+to descend to such or such a station, and there to remain suspended for
+some hours, till the heat by degrees were quite vanished, when it would
+again ascend to its former place. This I have also often observed naturally
+performed by the heat of the Air, which being able to rarifie the upper
+parts of the Water sooner then the lower, by reason of its immediate
+contact, the heat of the Air has sometimes so slowly increased, that I have
+observed the Bubble to be some hours in passing between the top and bottom.
+
+7. Whether the appearance of the _Pike_ of _Tenerif_, and several other
+high Mountains, at so much greater a distance then seems to agree with
+their respective heights, be not to be attributed to the _Curvature_ of the
+visual Ray, that is made by its passing obliquely through so differingly
+_Dense_ a Medium from the top to the eye very far distant in the Horizon:
+For since we have already, I hope, made it very probable, that there is
+such an _inflection_ of the Rays by the differing density of the parts of
+the Air; and since I have found, by several Experiments made on places
+comparatively not very high, and have yet found the pressure sustain'd by
+those parts of the Air at the top and bottom, and also their differing
+Expansions very considerable: Insomuch that I have found the pressure of
+the _Atmosphere_ lighter at the top of St. _Paul_'s Steeple in _London_
+(which is about two hundred foot high) then at the bottom by a sixtieth or
+fiftieth part, and the expansion at the top greater then that at the bottom
+by neer about so much also; for the _Mercurial Cylinder_ at the bottom was
+about 39. inches, and at the top half an inch lower; the Air also included
+in the Weather-glass, that at the bottom fill'd only 155. spaces, at the
+top fill'd 158. though the heat at the top and bottom was found exactly the
+same with a scal'd _Thermometer_: I think it very rational to suppose, that
+the greatest Curvature of the Rays is made nearest the Earth, and that the
+inflection of the Rays, above 3. or 4. miles upwards, is very
+inconsiderable, and therefore that by this means such calculations of the
+height of Mountains, as are made from the distance they are visible in the
+Horizon, from the supposal that that Ray is a straight Line (that from the
+top of the Mountain is, as 'twere, a Tangent to the Horizon whence it is
+seen) which really is a _Curve_, is very erroneous. Whence, I suppose,
+proceeds the reason of the exceedingly differing Opinions and Assertions of
+several Authors, about the height of several very high Hills.
+
+8. Whether this Inflection of the Air will not very much alter the supposed
+distances of the Planets, which seem to have a very great dependence upon
+the Hypothetical refraction or inflection of the Air, and that refraction
+upon the hypothetical height and density of the Air: For since (as I hope)
+I have here shewn the Air to be quite otherwise then has been hitherto
+suppos'd, by manifesting it to be, both of a vast, at least an uncertain,
+height, and of an unconstant and irregular density; It must necessarily
+follow, that its inflection must be varied accordingly: And therefore we
+may hence learn, upon what sure grounds all the Astronomers hitherto have
+built, who have calculated the distance of the Planets from their
+Horizontal _Parallax_; for since the Refraction and _Parallax_ are so
+nearly ally'd, that the one cannot be known without the other, especially
+by any wayes that have been yet attempted, how uncertain must the
+_Parallax_ be, when the Refraction is unknown? And how easie is it for
+Astronomers to assign what distance they please to the Planets, and defend
+them, when they have such a curious _subterfuge_ as that of Refraction,
+wherein a very little variation will allow them liberty enough to place the
+Celestial Bodies at what distance they please.
+
+If therefore we would come to any certainty in this point, we must go other
+wayes to work; and as I have here examined the height and refractive
+property of the Air by other wayes then are usual, so must we find the
+Parallax of the Planets by wayes not yet practiced; and to this end, I
+cannot imagine any better way, then the Observations of them by two persons
+at very far distant parts of the Earth, that lye as neer as may be under
+the same Meridian, or Degree of longitude, but differing as much in
+latitude, as there can be places conveniently found: These two persons, at
+certain appointed times, should (as near as could be) both at the same
+time, observe the way of the _Moon_, _Mars_, _Venus_, _Jupiter_, and
+_Saturn_, amongst the fixt Stars, with a good large _Telescope_, and making
+little Iconismes, or pictures, of the small fixed Stars, that appear to
+each of them to lye in or near the way of the Center of the Planet, and the
+exact measure of the apparent Diameter; from the comparing of such
+Observations together, we might certainly know the true distance, or
+Parallax, of the Planet. And having any one true Parallax of these Planets,
+we might very easily have the other by their apparent Diameters, which the
+_Telescope_ likewise affords us very accurately. And thence their motions
+might be much better known, and their Theories more exactly regulated. And
+for this purpose I know not any one place more convenient for such an
+Observation to be made in, then in the Island of St. _Helena_, upon the
+Coast of _Africk_, which lyes about sixteen degrees to the Southwards of
+the Line, and is very near, according to the latest Geographical Maps, in
+the same Meridian with _London_; for though they may not perhaps lye
+exactly in the same, yet their Observations, being ordered according to
+what I shall anon shew, it will not be difficult to find the true distance
+of the Planet. But were they both under the same Meridian, it would be much
+better.
+
+And because Observations may be much easier, and more accurately made with
+good _Telescopes_, then with any other Instruments, it will not, I suppose,
+seem impertinent to explain a little what wayes I judge most fit and
+convenient for that particular. Such therefore as shall be the Observators
+for this purpose, should be furnished with the best _Telescopes_ that can
+be had, the longer the better and more exact will their Observations be,
+though they are somewhat the more difficultly manag'd. These should be
+fitted with a _Rete_, or divided Scale, plac'd at such a distance within
+the Eye-glass, that they may be distinctly seen, which should be the
+measures of minutes and seconds; by this Instrument each Observator should,
+at certain prefixt times, observe the Moon, or other Planet, in, or very
+near, the Meridian; and because it may be very difficult to find two
+convenient stations that will happen to be just under the same Meridian,
+they shall, each of them, observe the way of the Planet, both for an hour
+before, and an hour after, it arrive at the Meridian; and by a line, or
+stroke, amongst the small fixed Stars, they shall denote out the way that
+each of them observ'd the Center of the Planet to be mov'd in for those two
+hours: These Observations each of them shall repeat for many dayes
+together, that both it may happen, that both of them may sometimes make
+their Observations together, and that from divers Experiments we may be the
+better assured of what certainty and exactness such kind of Observations
+are like to prove. And because many of the Stars which may happen to come
+within the compass of such an _Iconism_, or Map, may be such as are only
+visible through a good _Telescope_, whose Positions perhaps have not been
+noted, nor their longitudes, or latitudes, any where remarked; therefore
+each Observator should indeavour to insert some fixt Star, whose longitude,
+and latitude, is known; or with his _Telescope_ he shall find the Position
+of some notable _telescopical_ Star, inserted in his Map, to some known
+fixt Star, whose place in the _Zodiack_ is well defin'd.
+
+Having by this means found the true distance of the Moon, and having
+observed well the _apparent Diameter_ of it at that time with a good
+_Telescope_, it is easie enough, by one single Observation of the apparent
+Diameter of the Moon with a good Glass, to determine her distances in any
+other part of her _Orbit_, or _Dragon_, and consequently, some few
+Observations will tell us, whether she be mov'd in an _Ellipsis_, (which,
+by the way, may also be found, even now, though I think we are yet ignorant
+of her true distance) and next (which without such Observations, I think,
+we shall not be sure of) we may know exactly the bigness of that
+_Ellipsis_, or Circle, and her true velocity in each part, and thereby be
+much the better inabled to find out the true cause of all her Motions. And
+though, even now also, we may, by such Observations in one station, as here
+at _London_, observe the _apparent Diameter_ and motion of the Moon in her
+_Dragon_, and consequently be inabled to make a better ghess at the
+_Species_ or kind of Curve, in which she is mov'd, that is, whether it be
+sphærical, or _elliptical_, or neither, and with what proportional
+velocities she is carried in that Curve; yet till her true _Parallax_ be
+known, we cannot determine either.
+
+Next, for the true distance of the Sun, the best way will be, by accurate
+Observations, made in both these forementioned stations, of some convenient
+Eclipse of the Sun, many of which may so happen, as to be seen by both; for
+the _Penumbra_ of the Moon may, if she be sixty Semidiameters distant from
+the Earth, and the Sun above seven thousand, extend to about seventy
+degrees on the Earth, and consequently be seen by Observators as far
+distant as _London_, and St. _Helena_, which are not full sixty nine
+degrees distant. And this would much more accurately, then any way that has
+been yet used, determine the Parallax, and distance, of the Sun; for as for
+the Horizontal Parallax I have already shewn it sufficiently uncertain; nor
+is the way of finding it by the Eclipse of the Moon any other then
+hypothetical; and that by the difference of the true and apparent
+quadrature of the Moon is not less uncertain, witness their Deductions from
+it, who have made use of it; for _Vendeline_ puts that difference to be but
+4'.30". whence he deduces a vast distance of the Sun, as I have before
+shewn. _Ricciolo_ makes it full 30'.00. but _Reinoldus_, and _Kircher_, no
+less then three degrees. And no wonder, for if we examine the _Theory_, we
+shall find it so complicated with uncertainties.
+
+First, From the irregular surface of the Moon, and from several Parallaxes,
+that unless the _Dichotomy_ happen in the _Nonagesimus_ of the _Ecliptick_,
+and that in the Meridian, &c. all which happen so very seldom, that it is
+almost impossible to make them otherwise then uncertainly. Besides, we are
+not yet certain, but that there may be somewhat about the Moon _analogus_
+to the Air about the Earth, which may cause a refraction of the light of
+the Sun, and consequently make a great difference in the apparent
+_dichotomy_ of the Moon. Their way indeed is very rational and ingenious;
+and such as is much to be preferred before the way by the Horizontal
+Parallax, could all the uncertainties be remov'd, and were the true
+distance of the Moon known.
+
+But because we find by the Experiments of _Vendiline_, _Reinoldus_, &c.
+that Observations of this kind are very uncertain also: It were to be
+wisht, that such kind of Observations, made at two very distant stations,
+were promoted. And it is so much the more desirable, because, from what I
+have now shewn of the nature of the Air, it is evident, that the refraction
+may be very much greater then all the Astronomers hitherto have imagined
+it: And consequently, that the distance of the Moon, and other Planets, may
+be much lesse then what they have hitherto made it.
+
+For first, this Inflection, I have here propounded, will allow the shadow
+of the Earth to be much shorter then it can be made by the other
+_Hypothesis_ of refraction, and consequently, the Moon will not suffer an
+Eclipse, unless it comes very much nearer the Earth then the Astronomers
+hitherto have supposed it.
+
+Secondly, There will not in this _Hypothesis_ be any other shadow of the
+Earth, such as _Kepler_ supposes, and calls the _Penumbra_, which is the
+shadow of the refracting _Atmosphere_; for the bending of the Rays being
+altogether caus'd by _Inflection_, as I have already shewn, all that part
+which is ascribed by _Kepler_, and others after him, to the _Penumbra_, or
+dark part, which is without the _umbra terræ_, does clear vanish; for in
+this _Hypothesis_ there is no refracting surface of the Air, and
+consequently there can be no shadows, such as appear in the ninth Figure of
+the 37. _Scheme_, where let ABCD represent the Earth, and EFGH the
+_Atmosphere_, which according to _Keplers_ supposition, is like a Sphære of
+Water terminated with an exact surface EFGH, let the lines MF, LB, ID, KH,
+represent the Rays of the Sun; 'tis manifest, that all the Rayes between
+LB, and ID, will be reflected by the surface of the Earth BAD, and
+consequently, the conical space BOD would be dark and obscure; but, say the
+followers of _Kepler_, the Rays between MF, and LB, and between ID, and KH,
+falling on the _Atmosphere_, are refracted, both at their ingress and
+egress out of the _Atmosphere_, nearer towards the Axis of the sphærical
+shadow CO, and consequently, inlighten a great part of that former dark
+Cone, and shorten, and contract, its top to N. And because of this
+Reflection of these Rays, say they, there is superinduc'd another shell of
+a dark Cone FPH, whose Apex P is yet further distant from the Earth: By
+this _Penumbra_, say they, the Moon is Eclipsed, for it alwayes passes
+between the lines 12, and 34.
+
+To which I say, That if the Air be such, as I have newly shewn it to be,
+and consequently cause such an inflection of the Rays that fall into it,
+those dark _Penumbra's_ FYZQ, HXVT, and ORPS, will all vanish. For if we
+suppose the Air indefinitely extended, and to be no where bounded with a
+determinate refracting surface, as I have shewn it uncapable of having,
+from the nature of it; it will follow, that the Moon will no where be
+totally obscured, but when it is below the Apex N, of the dark blunt Cone
+of the Earth's shadow: Now, from the supposition, that the Sun is distant
+about seven thousand Diameters, the point N, according to calculation,
+being not above twenty five terrestrial Semidiameters from the Center of
+the Earth: It follows, that whensoever the Moon eclipsed is totally
+darkned, without affording any kind of light, it must be within twenty five
+Semidiameters of the Earth, and consequently much lower then any
+Astronomers have hitherto put it.
+
+This will seem much more consonant to the rest of the secundary Planets;
+for the highest of _Jupiter's_ Moons is between twenty and thirty _Jovial
+Semidiameters_ distant from the Center of _Jupiter_; and the Moons of
+_Saturn_ much about the same number of _Saturnial Semidiameters_ from the
+Center of that Planet.
+
+But these are but conjectures also, and must be determin'd by such kind of
+Observations as I have newly mention'd.
+
+Nor will it be difficult, by this _Hypothesis_, to salve all the
+appearances of Eclipses of the Moon, for in this _Hypothesis_ also, there
+will be on each side of the shadow of the Earth, a _Penumbra_, not caus'd
+by the Refraction of the Air, as in the _Hypothesis_ of _Kepler_; but by
+the faint inlightning of it by the Sun: For if, in the sixth Figure, we
+suppose ESQ, and GSR, to be the Rays that terminate the shadow from either
+side of the Earth; ESQ coming from the upper limb of the Sun, and GSR from
+the under; it will follow, that the shadow of the Earth, within those Rays,
+that is, the Cone GSE, will be totally dark. But the Sun being not a point,
+but a large _area_ of light, there will be a secondary dark Cone of shadow
+EPG, which will be caus'd by the earth's hindring part of the Rays of the
+Sun from falling on the parts GPR, and EPQ, of which halved shadow, or
+_Penumbra_, that part will appear brightest which lyes nearest the
+terminating Rayes GP, and EP, and those darker that lye nearest to GS, and
+ES: when therefore the Moon appears quite dark in the middle of the
+Eclipse, she must be below S, that is, between S and F; when she appears
+lighter near the middle of the Eclipse, she must pass some where between RQ
+and S; and when she is alike light through the whole Eclypse, she must pass
+between RQ, and P.
+
+       *       *       *       *       *
+
+
+Observ. LIX. _Of multitudes of small _Stars_ discoverable by the
+_Telescope_._
+
+Having, in the last Observation, premis'd some particulars observable in
+the _medium_, through which we must look upon _Coelestial_ Objects, I shall
+here add one Observation of the Bodies themselves; and for a _specimen_ I
+have made choice of the _Pleiades_, or seven Stars, commonly so called
+(though in our time and Climate there appear no more then six to the naked
+eye) and this I did the rather, because the deservedly famous _Galileo_,
+having publisht a Picture of this _Asterisme_, was able, it seems, with his
+Glass to discover no more then thirty six, whereas with a pretty good
+twelve foot _Telescope_, by which I drew this 38 _Iconism_, I could very
+plainly discover seventy eight, placed in the order they are ranged in the
+Figure, and of as many differing Magnitudes as the _Asterisks_, wherewith
+they are Marked, do specifie; there being no less then fourteen several
+Magnitudes of those Stars, which are compris'd within the draught, the
+biggest whereof is not accounted greater then one of the third Magnitude;
+and indeed that account is much too big, if it be compared with other Stars
+of the third Magnitude, especially by the help of a _Telescope_; for then
+by it may be perceiv'd, that its splendor, to the naked eye, may be
+somewhat augmented by the three little Stars immediately above it, which
+are near adjoyning to it. The _Telescope_ also discovers a great variety,
+even in the bigness of those, commonly reckon'd, of the first, second,
+third, fourth, fifth, and sixth Magnitude; so that should they be
+distinguish'd thereby, those six Magnitudes would, at least, afford no less
+then thrice that number of Magnitudes, plainly enough distinguishable by
+their Magnitude, and brightness; so that a good twelve foot Glass would
+afford us no less then twenty five several Magnitudes. Nor are these all,
+but a longer Glass does yet further, both more nicely distinguish the
+Magnitudes of those already noted, and also discover several other of
+smaller Magnitudes, not discernable by the twelve foot Glass: Thus have I
+been able, with a good thirty six foot Glass, to discover many more Stars
+in the _Pleiades_ then are here delineated, and those of three or four
+distinct Magnitudes less then any of those spots of the fourteenth
+Magnitude. And by the twinkling of divers other places of this _Asterisme_,
+when the Sky was very clear, I am apt to think, that with longer Glasses,
+or such as would bear a bigger _aperture_, there might be discovered
+multitudes of other small Stars, yet inconspicuous. And indeed, for the
+discovery of small Stars, the bigger the _aperture_ be, the better adapted
+is the Glass; for though perhaps it does make the several specks more
+radiant, and glaring, yet by that means, uniting more Rays very near to one
+point, it does make many of those radiant points conspicuous, which, by
+putting on a less _aperture_, may be found to vanish; and therefore, both
+for the discovery of the fixt Star, and for finding the _Satellites_ of
+_Jupiter_, before it be out of the day, or twilight, I alwayes leave the
+Object-glass as clear without any _aperture_ as I can, and have thereby
+been able to discover the _Satellites_ a long while before; I was able to
+discern them, when the smaller _apertures_ were put on; and at other times,
+to see multitudes of other smaller Stars, which a smaller _aperture_ makes
+to disappear.
+
+In that notable _Asterism_ also of the Sword of _Orion_, where the
+ingenious Monsieur _Hugens van Zulichem_ has discovered only three little
+Stars in a cluster, I have with a thirty six foot Glass, without any
+_aperture_ (the breadth of the Glass being about some three inches and a
+half) discover'd five, and the twinkling of divers others up and down in
+divers parts of that small milky Cloud.
+
+So that 'tis not unlikely, but that the meliorating of _Telescopes_ will
+afford as great a variety of new Discoveries in the Heavens, as better
+_Microscopes_ would among small terrestrial Bodies, and both would give us
+infinite cause, more and more to admire the omnipotence of the Creator.
+
+       *       *       *       *       *
+
+
+Observ. LX. _Of the _Moon_._
+
+Having a pretty large corner of the Plate for the seven Starrs, void, for
+the filling it up, I have added one small _Specimen_ of the appearance of
+the parts of the Moon, by describing a small spot of it, which, though
+taken notice of, both by the Excellent _Hevelius_, and called _Mons
+Olympus_ (though I think somewhat improperly, being rather a vale) and
+represented by the Figure X. of the 38. _Scheme_, and also by the Learn'd
+_Ricciolus_, who calls it _Hipparchus_, and describes it by the Figure Y,
+yet how far short both of them come of the truth, may be somewhat perceiv'd
+by the draught, which I have here added of it, in the Figure Z, (which I
+drew by a thirty foot Glass, in _October_ 1664. just before the Moon was
+half inlightned) but much better by the Reader's diligently observing it
+himself, at a convenient time, with a Glass of that length, and much better
+yet with one of threescore foot long, for through these it appears a very
+spacious Vale, incompassed with a ridge of Hills, not very high in
+comparison of many other in the Moon, nor yet very steep. The Vale it self
+ABCD, is much of the figure of a Pear, and from several appearances of it,
+seems to be some very fruitful place, that is, to have its surface all
+covered over with some kinds of vegetable substances; for in all positions
+of the light on it, it seems to give a much fainter reflection then the
+more barren tops of the incompassing Hills, and those a much fainter then
+divers other cragged, chalky, or rocky Mountains of the Moon. So that I am
+not unapt to think, that the Vale may have Vegetables _analogus_ to our
+Grass, Shrubs, and Trees; and most of these incompassing Hills may be
+covered with so thin a vegetable Coat, as we may observe the Hills with us
+to be, such as the short Sheep pasture which covers the Hills of
+_Salisbury_ Plains.
+
+Up and down in several parts of this place here describ'd (as there are
+multitudes in other places all over the surface of the Moon) may be
+perceived several kinds of pits, which are shap'd almost like a dish, some
+bigger, some less, some shallower, some deeper, that is, they seem to be a
+hollow _Hemisphere_, incompassed with a round rising bank, as if the
+substance in the middle had been digg'd up, and thrown on either side.
+These seem to me to have been the effects of some motions within the body
+of the Moon, _analogus_ to our Earthquakes, by the eruption of which, as it
+has thrown up a brim, or ridge, round about, higher then the Ambient
+surface of the Moon, so has it left a hole, or depression, in the middle,
+proportionably lower; divers places resembling some of these, I have
+observ'd here in _England_, on the tops of some Hills, which might have
+been caus'd by some Earthquake in the younger dayes of the world. But that
+which does most incline me to this belief, is, first, the generality and
+diversity of the Magnitude of these pits all over the body of the Moon.
+Next, the two experimental wayes, by which I have made a representation of
+them.
+
+The first was with a very soft and well temper'd mixture of Tobacco-pipe
+clay and Water, into which, if I let fall any heavy body, as a Bullet, it
+would throw up the mixture round the place, which for a while would make a
+representation, not unlike these of the Moon; but considering the state and
+condition of the Moon, there seems not any probability to imagine, that it
+should proceed from any cause _analogus_ to this; for it would be difficult
+to imagine whence those bodies should come; and next, how the substance of
+the Moon should be so soft; but if a Bubble be blown under the surface of
+it, and suffer'd to rise, and break; or if a Bullet, or other body, sunk in
+it, be pull'd out from it, these departing bodies leave an impression on
+the surface of the mixture, exactly like these of the Moon, save that these
+also quickly subside and vanish. But the second, and most notable,
+representation was, what I observ'd in a pot of boyling Alabaster, for
+there that powder being by the eruption of vapours reduc'd to a kind of
+fluid consistence, if, whil'st it boyls, it be gently remov'd besides the
+fire, the Alabaster presently ceasing to boyl, the whole surface,
+especially that where some of the last Bubbles have risen, will appear all
+over covered with small pits, exactly shap'd like these of the Moon, and by
+holding a lighted Candle in a large dark Room, in divers positions to this
+surface, you may exactly represent all the _Phænomena_ of these pits in the
+Moon, according as they are more or less inlightned by the Sun.
+
+And that there may have been in the Moon some such motion as this, which
+may have made these pits, will seem the more probable, if we suppose it
+like our Earth, for the Earthquakes here with us seem to proceed from some
+such cause, as the boyling of the pot of Alabaster, there seeming to be
+generated in the Earth from some subterraneous fires, or heat, great
+quantities of vapours, that is, of expanded aerial substances, which not
+presently finding a passage through the ambient parts of the Earth, do, as
+they are increased by the supplying and generating principles, and thereby
+(having not sufficient room to expand themselves) extreamly condens'd, at
+last overpower, with their _elastick_ properties, the resistence of the
+incompassing Earth, and lifting it up, or cleaving it, and so shattering of
+the parts of the Earth above it, do at length, where they find the parts of
+the Earth above them more loose, make their way upwards, and carrying a
+great part of the Earth before them, not only raise a small brim round
+about the place, out of which they break, but for the most part
+considerable high Hills and Mountains, and when they break from under the
+Sea, divers times, mountainous Islands; this seems confirm'd by the
+_Vulcans_ in several places of the Earth, the mouths of which, for the most
+part, are incompassed with a Hill of a considerable height, and the tops of
+those Hills, or Mountains, are usually shap'd very much like these pits, or
+dishes, of the Moon: Instances of this we have in the descriptions of
+_Ætna_ in _Sicily_, of _Hecla_ in _Iceland_, of _Tenerif_ in the
+_Canaries_, of the several _Vulcans_ in _New-Spain_, describ'd by _Gage_,
+and more especially in the eruption of late years in one of the _Canary_
+Islands. In all of which there is not only a considerable high Hill raised
+about the mouth of the _Vulcan_, but, like the spots of the Moon, the top
+of those Hills are like a dish, or bason. And indeed, if one attentively
+consider the nature of the thing, one may find sufficient reason to judge,
+that it cannot be otherwise; for these eruptions, whether of fire, or
+smoak, alwayes raysing great quantities of Earth before them, must
+necessarily, by the fall of those parts on either side, raise very
+considerable heaps.
+
+Now, both from the figures of them, and from several other circumstances;
+these pits in the Moon seem to have been generated much after the same
+manner that the holes in Alabaster, and the _Vulcans_ of the Earth are
+made. For first, it is not improbable, but that the substance of the Moon
+may be very much like that of our Earth, that is, may consist of an earthy,
+sandy, or rocky substance, in several of its superficial parts, which parts
+being agitated, undermin'd, or heav'd up, by eruptions of vapours, may
+naturally be thrown into the same kind of figured holes, as the small dust,
+or powder of Alabaster. Next, it is not improbable, but that there may be
+generated, within the body of the Moon, divers such kind of internal fires
+and heats, as may produce such Exhalations; for since we can plainly enough
+discover with a _Telescope_, that there are multitudes of such kind of
+eruptions in the body of the Sun it self, which is accounted the most noble
+Ætherial body, certainly we need not be much scandaliz'd at such kind of
+alterations, or corruptions, in the body of this lower and less
+considerable part of the universe, the Moon, which is only secundary, or
+attendant, on the bigger, and more considerable body of the Earth. Thirdly,
+'tis not unlikely, but that supposing such a sandy or mouldring substance
+to be there found, and supposing also a possibility of the generation of
+the internal _elastical_ body (whether you will call it air or vapours)
+'tis not unlikely, I say, but that there is in the Moon a principle of
+gravitation, such as in the Earth. And to make this probable, I think, we
+need no better Argument, then the roundness, or globular Figure of the body
+of the Moon it self, which we may perceive very plainly by the _Telescope_,
+to be (bating the small inequality of the Hills and Vales in it, which are
+all of them likewise shap'd, or levelled, as it were, to answer to the
+center of the Moons body) perfectly of a Sphærical figure, that is, all the
+parts of it are so rang'd (bating the comparitively small ruggedness of the
+Hills and Dales) that the outmost bounds of them are equally distant from
+the Center of the Moon, and consequently, it is exceedingly probable also,
+that they are equidistant from the Center of gravitation; and indeed, the
+figure of the superficial parts of the Moon are so exactly shap'd,
+according as they should be, supposing it had a gravitating principle as
+the Earth has, that even the figure of those parts themselves is of
+sufficient efficacy to make the gravitation, and the other two suppositions
+probable: so that the other suppositions may be rather prov'd by this
+considerable Circumstance, or Observation, then this suppos'd Explication
+can by them; for he that shall attentively observe with an excellent
+_Telescope_, how all the Circumstances, notable in the shape of the
+superficial parts, are, as it were, exactly adapted to suit with such a
+principle, will, if he well considers the usual method of Nature in its
+other proceedings, find abundant argument to believe it to have really
+there also such a principle; for I could never observe, among all the
+mountainous or prominent parts of the Moon (whereof there is a huge
+variety) that any one part of it was plac'd in such a manner, that if there
+should be a gravitating, or attracting principle in the body of the Moon,
+it would make that part to fall, or be mov'd out of its visible posture.
+Next, the shape and position of the parts is such, that they all seem put
+into those very shapes they are in by a gravitating power: For first, there
+are but very few clifts, or very steep declivities in the ascent of these
+Mountains; for besides those Mountains, which are by _Hevelius_ call'd the
+_Apennine_ Mountains, and some other, which seem to border on the Seas of
+the Moon, and those only upon one side, as is common also in those Hills
+that are here on the Earth; there are very few that seem to have very steep
+ascents, but, for the most part, they are made very round, and much
+resemble the make of the Hills and Mountains also of the Earth; this may be
+partly perceived by the Hills incompassing this Vale, which I have here
+describ'd; and as on the Earth also, the middlemost of these Hills seems
+the highest, so is it obvious also, through a good _Telescope_, in those of
+the Moon; the Vales also in many are much shap'd like those of the Earth,
+and I am apt to think, that could we look upon the Earth from the Moon,
+with a good _Telescope_, we might easily enough perceive its surface to be
+very much like that of the Moon.
+
+Now whereas in this small draught, (as there would be multitudes if the
+whole Moon were drawn after this manner) there are several little
+Ebullitions, or Dishes, even in the Vales themselves, and in the
+incompassing Hills also; this will, from this supposition, (which I have, I
+think, upon very good reason taken) be exceeding easily explicable; for, as
+I have several times also observ'd, in the surface of Alabaster so ordered,
+as I before describ'd, so may the later eruptions of vapours be even in the
+middle, or on the edges of the former; and other succeeding these also in
+time may be in the middle or edges of these, &c. of which there are
+Instances enough in divers parts of the body of the Moon, and by a boyling
+pot of Alabaster will be sufficiently exemplifi'd.
+
+To conclude therefore, it being very probable, that the Moon has a
+principle of gravitation, it affords an excellent distinguishing Instance
+in the search after the cause of gravitation, or attraction, to hint, that
+it does not depend upon the diurnal or turbinated motion of the Earth, as
+some have somewhat inconsiderately supposed and affirmed it to do; for if
+the Moon has an attractive principle, whereby it is not only shap'd round,
+but does firmly contain and hold all its parts united, though many of them
+seem as loose as the sand on the Earth, and that the Moon is not mov'd
+about its Center; then certainly the turbination cannot be the cause of the
+attraction of the Earth, and therefore some other principle must be thought
+of, that will agree with all the secundary as well as primary Planets. But
+this, I confess, is but a probability, and not a demonstration, which (from
+any Observation yet made) it seems hardly capable of, though how successful
+future indeavours (promoted by the meliorating of Glasses, and observing
+particular circumstances) may be in this, or any other, kind, must be with
+patience expected.
+
+       *       *       *       *       *
+
+
+_FINIS._
+
+       *       *       *       *       *
+
+
+THE TABLE.
+
+Observat. 1. Of the point of a Needle.
+
+_A Description of it: what other Bodies have the sharpest points: of the
+ruggedness of polisht Metal. A description of a printed point. Of very
+small writing, and the use of it for secret intelligence: the cause of the
+coursness of printed lines and points._
+
+Observ. 2. Of the Edge of a Razor.
+
+_A description of it: the causes of its roughness: of the roughness of very
+well polisht Optick Glasses._.
+
+Obser. 3. Of fine Lawn.
+
+_A description of it: A silken Flax mention'd, an attempt to explicate the
+_Phænomena_ of it, with a conjecture at the cause of the gloss of Silk._
+
+Observ. 4. Of Tabby.
+
+_A short description of it. A conjecture about the reason why Silk is so
+susceptible of vivid colours: and why Flax and Hair is not. A conjecture,
+that it way perhaps be possible to spin a kind of artificial Silk, out of
+some glutinous substance that may equalize natural Silk._
+
+Observ. 5. Of water'd Silks.
+
+_The great unaccurateness of artificial works. A description of a piece of
+water'd Silk; an Explication of the cause of the _Phænomena_: the way by
+which that operation is perform'd: some other _Phænomena_ mention'd
+depending on the same cause._
+
+Observ. 6. Of Glass-Canes.
+
+_The exceeding smallness of some of these Bodies. By what means the
+hollowness of these small pipes was discover'd: several _Phænomena_ of it
+mention'd. An attempt to explicate them from the congruity and incongruity
+of Bodies: what those proprieties are. A hypothetical explication of
+fluidity: of the fluidity of the air, and several other _Phænomena_ of it:
+of congruity & incongruity; illustrated with several Experiments: what
+effects may be ascrib'd to these properties: an explication of the
+roundness of the surface of fluid Bodies: how the ingress of fluid bodies
+into a small hole of an heterogenious body is hindred by incongruity; a
+multitude of _Phænomena_ explicable hereby. Several Quæries propounded; 1.
+Concerning the propagation of light through differing mediums. 2.
+Concerning Gravity. 3. Concerning the roundness of the Sun, Moon, and
+Planets. 4. Concerning the roundness of Fruits, Stones, and divers
+artificial Bodies. His Highness Prince _Rupert's_ way of making Shot. Of
+the roundness of Hail. Of the grain of _Kettering_ Stone, and of the Sparks
+of fire. 5. Concerning springiness and tenacity. 6. Concerning the original
+of Fountains; several Histories and Experiments relating thereto. 7.
+Concerning the dissolution of Bodies in Liquors. 8. Concerning the
+universality of this Principle: what method was taken in making and
+applying experiments. The explication of filtration, and several other
+_Phænomena_; such as the motion of Bodies on the surface of Liquors;
+several Experiments mention'd to this purpose. Of the height to which the
+water may rise in these Pipes; and a conjecture about the juices of
+Vegetables, & the use of their pores. A further explication of Congruity:
+And an attempt of solving the _Phænomena_ of the strange Experiment of the
+suspension of the _Mercury_ at a much greater height then thirty inches.
+The efficacy of immediate contact, and the reason of it._
+
+Observ. 7. Of Glass drops.
+
+_Several Experiments made with these small Bodies. The manner of the
+breaking and flawing of them, explicated by Figures. What other bodies will
+be flawed much in the same manner: so other tryals, and a description of
+the Drops themselves: some conjectures at the cause of the _Phænomena_,
+indeavoured to be made probable by several Arguments and Experiments. An
+Experiment of the expansion of Water by heat, and shrinking by cold: the
+like Proprieties suppos'd in Glass drops, and what effects proceed from
+them: the seven Propositions on which the conjectures are grounded.
+Experiments to shew, that bodies expand by heat. The manner of making
+_Thermometers_, and the Instrument for _graduating_ them. The manner of
+_graduating_ them, and their use: Other Experiments to prove the expansion
+of bodies by heat. Four experimental Arguments to prove the expansion of
+Glass by heat: further prov'd by the Experiment of boyling Alabaster; which
+is explicated. An explication of the contracting of heated Glass upon
+cooling. An explication how the parts of the Glass become bent by sudden
+cold, and how kept from extricating themselves by the contignation of the
+Glass drop; which is further explicated by another Experiment made with a
+hollow Glass ball: the reason of the flying asunder of the parts further
+explicated: that 'tis probable these bodies may have many flaws, though not
+visible, and why: how a gradual heating and cooling does put the parts of
+Glass, and other hardned bodies, into a looser texture._
+
+Observ. 8. Of Fiery Sparks.
+
+_The occasion and manner of making this Experiment: divers Observations set
+down in order to the finding out the reasons: some conjectures concerning
+it, which are endeavoured to be explicated and confirm'd by several
+Experiments and Reasons: the _Hypothesis_ a little further explicated. Some
+Observations about the Globular Figure: and an Experiment of reducing the
+filings of Tin or Lead to exactly round Globules._
+
+Observ. 9. Of Fantastical Colours.
+
+_The texture of _Muscovy_ Glass; its Figures: what other Bodies are like
+it: that it exhibits several colours, and how: several Observations and
+Experiments about those colours: the reason why on this occasion the nature
+of colours is inquir'd into. A conjecture at the reason of these colours
+explicated by several Experiments and Reasons: First, by continual cleaving
+the Body till it become colour'd. Secondly, by producing all kinds of
+colours with two flat Plates of Glass. Thirdly, by blowing Glass so thin in
+the Lamp, till it produce the same effect. Fourthly, by doing the same with
+Bubbles of divers other transparent Bodies: the reasons of the colours on
+nealed Steel, where by the way the causes of the hardning and tempering of
+Steel, endeavour'd to be shewn and explicated by several Reasons and
+Experiments: the reason of the colours on Lead, Brass, Copper, Silver, &c.
+other Instances of such colour'd bodies in animal substances: several other
+distinguishing Observations. _Des Cartes Hypothesis_ of Colours examin'd.
+An _Hypothesis_ for the explication of light by motion, indeavoured to be
+explicated and determined by several Reasons and Experiments: three
+distinguishing Properties of the motion of light. The distinguishing
+Properties of a trasparent _Medium_ [that there seems to be no Experiment
+that proves the Instantaneous motion of light] the manner of the
+propagation of light through them. Of the _homogeniety_ and _heterogeniety_
+of transparent _Mediums_, and what effects they cause on the Rayes of
+light, explicated by a Figure: an Examination of the refraction of the Rays
+by a plain Surface, which causes Colours. An Examination of the like
+effects produced by a spherical Surface: the use that may be made of these
+Experiments, for the examination of several _Hypotheses_ of Colours. _Des
+Cartes Hypothesis_ examin'd. Some Difficulties taken notice of in it. What
+seems most likely to be the cause of colour: that propriety is indeavoured
+to be shewn in a Glass ball: that the reflection is not necessary to
+produce Colours nor a double refraction: the _Hypothesis_ further examined,
+both in the _pellucid Medium_ and in the Eye. The definitions of Colours;
+and a further explication and examination of the Proprieties of _laminated_
+Bodies; by what means they conduce to the production of Colours._
+
+Observ. 10. Of Metalline Colours.
+
+_That all Colours seem to be caus'd by refraction. An _Hypothesis_
+consonant hereunto, explicated by Figures. How several Experiments, of the
+sudden changing of Colours by Chymical Liquors may be hereby explicated:
+how many wayes such Chymical Liquors may alter the colours of Bodies.
+Objections made against this _Hypothesis_ of two colours only, indeavoured
+to be answer'd, by several Reasons and Experiments. The reason why some
+Colours are capable of being diluted, others not: what those are: that
+probably the particles of most metalline Colours are transparent; for this
+several Arguments and Observations are recited: how Colours become
+incapable of diluting, explicated by a Similitude. An Instrument, by which
+one and the same coloured Liquor at once exhibited all the degrees of
+colours between the palest yellow and deepest red: as likewise another that
+exhibited all varieties of blues: several Experiments try'd with these
+Boxes. An Objection drawn from the nature of Painters colours answered:
+that diluting and whitening a colour are different operations; as are
+deepening and blackening: why some may be diluted by grinding, and some
+other by being tempered with Oyl: several Experiments for the explicating
+of some former Assertions: why Painters are forced to make use of many
+colours: what those colours are: and how mixt. The conclusion, that most
+coloured Bodies seem to consist of transparent particles: that all colours
+dissoluble in Liquors are capable of diluting: some of mixing, what a
+strange variety may thereby be produc'd._
+
+Observ. 11. Of the Figures of Sand.
+
+_Of the substances and shapes of common and other Sands: a description of a
+very small Shell._
+
+Observ. 12. Of Gravel in Urine.
+
+_A description of such Gravel, and some tryals made with it, and
+conjectures at its cause._
+
+Obser. 13. Of Diamonds in Flints.
+
+_A description and examination of some of them, explicated further by
+Cornish Diamonds: several Observations about reflection and refraction:
+and some deductions therefrom; as an explication of whiteness; that the Air
+has a stronger reflection then Water. How several Bodies may be made
+transparent: an explication of the _Phænomena_ of _Oculus Mundi_. Of the
+regular Geometrical Figures of several Bodies: an hypothetical explication
+mentioned: the method of prosecuting this inquiry._
+
+Observ. 14. Of frozen Figure.
+
+_The Figures of hoar Frost, and the Vortices on windows: several
+Observations on the branched Figures of Urine: the Figures of _Regulus
+Martis stellatus_, and of Fern. Of the Figures of Snow. Of frozen water._
+
+Observ. 15. Of Kettering Stone.
+
+_A description of the Figure of the Particles, and of the Pores, and of the
+Contexture. Several Observations and Considerations thereupon: some
+Conjectures about the _medium_ and propagation of light, and the
+constitution of fluid and transparent Bodies. Several Experiments to prove
+the porousness of Marble, and some other Stones. An account of some
+Experiments to this purpose made on an _Oculus Mundi_: some other
+Considerations and Experiments about the porousness of Bodies: some other
+Considerations about the propagation of light and refraction._
+
+Observ. 16. Of Charcoal.
+
+_Of two sort of Pores to be found in all Woods and Vegetables; the shape of
+them; the number, thickness, manner and use of these Pores. An explication
+of the _Phænomena_ of Coals. The manner of charring Wood, or any other
+body. What part of Wood is combustible. An _Hypothesis_ of fire explicated
+in twelve particulars, wherein the Action of the Air, as a _Menstruum_ in
+the dissolution of all sulphureous bodies, is very particularly explicated,
+and some other Considerations about the Air proposed: the examination of a
+piece of _Lignum fossile_ sent from _Rome_, and some Conclusions thence
+deduc'd._
+
+Observ. 17. Of Wood, and other Bodies, petrified.
+
+_Several Observations of divers kinds of these substances. A more
+particular examination and explication of one very notable piece of
+petrified Wood; and some Conjectures about the cause of those productions:
+several Observations made on other petrified Bodies, as shells, &c. And
+some probable Conclusions thence deduc'd, about the original cause of those
+Bodies._
+
+Observ. 18. Of the Pores of Cork, and other Bodies.
+
+_Several Observations and Considerations about the nature of Cork: the
+number of Pores in a cubical Inch, and several considerations about Pores.
+Several Experiments and Observations about the nature of Cork: the Texture
+and Pores of the Pith of an Elder, and several other Trees: of the Stales
+of Burdocks, Teasels, Daisies, Carret, Fennel, Ferne, Reeds, &c. of the
+frothy texture of the Pith of a Feather: some Conjectures about the
+probability of values in these Pores. Argued also from the _Phænomena_ of
+sensible and humble Plant: some Observations on which are inserted._
+
+Observ. 19. Of a Vegetable growing on blighted Leaves.
+
+_Several Observations and Examinations made of them: several Considerations
+about spontaneous generation arising from the putrefaction of Bodies._
+
+Observ. 20. Of Blew Mould and Mushromes.
+
+_The description of several kinds of Moulds. The method of proceeding in
+natural Inquiries. Several Considerations about the nature of Mould and
+Mushromes. 1. That they may be produc'd without seed. 2. That they seem to
+have none. 3. That Salts, &c. are shap'd into as curious figures without a
+seed. 4. Of a kind of Mushrome growing in a Candle: A more particular
+explication of this last sort of Mushromes. 5. Of the figure and manner of
+the production of petrified Iceicles: several deductions from these
+Considerations, about the nature of the vegetation of Mould and Mushromes._
+
+Observ. 21. Of Moss.
+
+_The description of several sorts of Mosses; upon this occasion several
+Conjectures, about the manner of the production of these kinds of Bodies,
+are hinted, and some of them explicated by a Similitude taken from a piece
+of Clock-work, The vast difference of the bigness of vegetable Bodies; and
+the probability that the least may comprehend as curious contrivances as
+the greatest. Of multitudes of other Moulds, Mosses, and Mushromes, and
+other vegetating Principles, in Water, Wood, _&c.
+
+Observ. 22. Of Sponges, and other fibrous Bodies.
+
+_Several Observations and Conjectures about the making of these Bodies, and
+several Histories out of Authors. Scarce any other Body hath such a
+texture; the fibrous texture of Leather, Spunk, &c. (which are there
+describ'd) come nearest to it That upon tryal with a piece of Spunge and
+Oyl the necessity of respiration could not be alter'd._
+
+Observ. 23. Of the Form of Seaweed.
+
+_From the curiously shap'd Surface of this Sea-weed, and some others, is
+conjectured the possibility of Multitudes of the like._
+
+Observ. 24. Of the Surfaces of some Leaves.
+
+_The description, 1. Of the bald Surfaces of Leaves. 2. Of the downy
+Surfaces of several others. 3. Of the gummous exsudation, or small
+transparent Pearls, discovered with a _Microscope_ in several others. An
+Instance of all which is afforded in a Rosemary Leaf._
+
+Observ. 25. Of the stinging Points of a Nettle.
+
+_A description of the Needles and several other contrivances in the leaf of
+a Nettle: how the stinging pain is created: upon this several
+considerations about poysoning Darts are set down. An Experiment of killing
+Effs, and Fishes with Salt. Some conjectures at the efficacy of Baths; the
+use that may be made of injecting into the Veins. A very remarkable History
+out of _Bellonius_; and some Considerations about staining and dying of
+Bodies._
+
+Observ. 26. Of Cowage.
+
+_The definition of it out of _Parkinson_: an Experiment made of it: a
+description, and some conjectures at the cause of the _Phænomena_._
+
+Observ. 27. Of the Beard of a wild Oat.
+
+_The description of its shape and properties: the manner of making a
+_Hygroscope_ with it; and a Conjecture at the causes of these motions, and
+of the motions of the Muscles._
+
+Observ. 28. Of the Seeds of _Venice_ Looking-glass.
+
+_The description of them._
+
+Obser. 29. Of the Seeds of Time.
+
+_A description of them. A digression about Natures method._
+
+Observ. 30. Of Poppy Seeds.
+
+_The description and use of them._
+
+Observ. 31. Of Purslane Seeds.
+
+_A description of these and many other Seeds._
+
+Observ. 32. Of Hair.
+
+_The description of several sorts of Hair; their Figures and Textures: the
+reason of their colours, A description of the texture of the skin, and of
+Spunk and Sponges: by what passages and pores of the skin transpiration
+seems to be made. Experiments to prove the porousness of the skin of
+Vegetables._
+
+Observ. 33. Of the Scales of a Soale.
+
+_A description of their beauteous form._
+
+Observ. 34. Of the Sting of a Bee.
+
+_A description of its shape, mechanisme, and use._
+
+Observ. 35. Of Feathers.
+
+_A description of the shape and curious contexture of Feathers: and some
+conjectures thereupon._
+
+Obser. 36. Of Peacocks Feathers.
+
+_A description of their curious form and proprieties; with a conjecture at
+the cause of their variable colours._
+
+Obser. 37. Of the Feet of Flyes, and other Insects.
+
+_A description of their figure, parts, and use; and some considerations
+thereupon._
+
+Obser. 38. Of the Wings of Flyes.
+
+_After what manner and how swiftly the wings of Insects move. A description
+of the Pendulums under the wings, and their motion; the shape and structure
+of the parts of the wing._
+
+Obser. 39. Of the Head of a Fly.
+
+_1. All the face of a Drone-fly is nothing almost but eyes. 2. Those are of
+two magnitudes. 3. They are Hemispheres, and very reflective and smooth. 4.
+Some directed towards every quarter. 5. How the fly cleanses them. 6. Their
+number. 7. Their order: divers particulars observ'd in the dissecting a
+head. That these are very probably the eyes of the Creature; argued from
+several Observations and Experiments, that Crabs, Lobsters, Shrimps, seem
+to be water Insects, and to be framed much like Air Insects. Several
+Considerations about their manner of vision._
+
+Obser. 40. Of the Teeth of a Snail.
+
+_A brief description of it._
+
+Observ. 41. Of the Eggs of Silkworms.
+
+_Several Observables about the Eggs of Insects._
+
+Observ. 42. Of a blue Fly.
+
+_A description of its outward and inward parts. Its hardiness to indure
+freezing, and sleeping in Spirit of wine._
+
+Observ. 43. Of a water Insect.
+
+_A description of its shape, transparency, motion, both internal and
+progressive, and transformation. A History somewhat _Analogus_ cited out of
+_Piso_. Several Observations about the various wayes of the generations of
+Insects: by what means they act so seemingly wisely and prudently. Several
+Quæries propounded. Postscript, containing a relation of another very odd
+way of the generation of Insects. An Observation about the fertility of the
+Earth of our Climate in producing Insects, and of divers other wayes of
+their generation._
+
+Observ. 44. Of the tufted Gnat.
+
+_Several Observables about Insects, and a more particular description the
+parts of this Gnat._
+
+Ob. 45. Of the great belly'd Gnat.
+
+_A short description of it._
+
+Obser. 46. Of a white Moth.
+
+_A description of the feathers and wings of this, and several other
+Insects. Divers Considerations about the wings, and the flying of Insects
+and Birds._
+
+Obs. 47. Of the Shepherd Spider.
+
+_A description of its Eyes: and the sockets of its long legs: and a
+Conjecture of the mechanical reason of its fabrick; together with a
+supposition, that 'tis not unlikely, but Spiders may have the make of their
+inward parts exactly like a Crab, which may be call'd a water Spider._
+
+Obser. 48. Of the hunting Spider.
+
+_A short description of it; to which is annext an excellent History of it,
+made by Mr. _Evelyn_. Some further Observations on other Spiders, and their
+Webs, together with an examination of a white Substance flying up and down
+in the Air after a Fog._
+
+Obser. 49. Of an Ant.
+
+_That all small Bodies, both Vegetable and Animal, do quickly dry and
+wither. The best remedy I found to hinder it, and to make the Animal lye
+still to be observ'd. Several particulars related of the actions of this
+Creature and a short description of its parts._
+
+Obs. 50. Of the wandring Mite.
+
+_A description of this Creature, and of another very small one, which
+usually bore it company. A Conjecture at the original of Mites._
+
+Observ. 51. Of a Crab-like Insect.
+
+_A brief description of it._
+
+Observ. 52. Of a Book-worm.
+
+_A description of it; where by the way is inserted a digression,
+experimentally explicating the _Phænomena_ of Pearl. A consideration of its
+digestive faculty._
+
+Observ. 53. Of a Flea.
+
+_A short description of it._
+
+Observ. 54. Of a Louse.
+
+_A description of its parts, and some notable circumstances._
+
+Observ. 55. Of Mites.
+
+_The exceeding smalness of some Mites, and their Eggs. A description of the
+Mites of Cheese: and an intimation of the variety of forms in other Mites,
+with a Conjecture at the reason._
+
+Ob. 56. Of small Vine-Mites.
+
+_A description of them; a ghess at their original; their exceeding smalness
+compar'd with that of a Wood-louse, from which they may be suppos'd to
+come._
+
+Observ. 57. Of Vinegar-worms.
+
+_A description of them, with some considerations on their motions._
+
+Obs. 58. Of the Inflexion of the Rays of Light in the Air.
+
+_A short rehearsal of several _Phænomena_. An attempt to explicate them:
+the supposition founded on two Propositions, both which are indeavoured to
+be made out by several Experiments, What density and rarity is in respect
+of refraction: the refraction of Spirit of Wine compared with that of
+common Water: the refraction of Ice. An Experiment of making an Undulation
+of the Rays by the mixing of Liquors of differing density. The explication
+of _inflection_, mechanically and hypothetically: what Bodies have such an
+inflection. Several Experiments to shew that the Air has this propriety;
+that it proceeds from the differing density of the Air: that the upper and
+under part of the Air are of differing density: some Experiments to prove
+this. A Table of the strength of the spring of the Air, answering to each
+degree of extension; when first made, and when repeated. Another Experiment
+of compressing the Air. A Table of the strength of the Air, answering to
+each compression and expansion; from which the height of the Air may be
+suppos'd indefinite; to what degree the Air is rarifi'd at any distance
+above the Surface of the Earth: how, from this, Inflection is inferr'd; and
+several _Phænomena_ explain'd. That the Air near the Earth is compos'd of
+parts of differing density; made probable by several Experiments and
+Observations; how this propriety produces the effects of the waving and
+dancing of Bodies; and of the twinkling of the Stars. Several _Phænomena_
+explicated. Some Quæries added._
+
+1. _Whether this Principle may not be made use of, for perfecting Optick
+Glasses? What might be hoped from it if it were to be done?_
+
+2. _Whether from this Principle the apparition of some new Stars may not be
+explicated?_
+
+3. _Whether the height of the Air may be defin'd by it?_
+
+4. _Whether there may not sometimes be so great a disparity of density
+between the upper and under parts of the Air, as to make a reflecting
+Surface?_
+
+5. _Whether, if so, this will not explicate the _Phænomena_ of the Clouds.
+An Experiment to this purpose?_
+
+7. _Whether the Rayes from the top of Mountains are not bended into
+Curve-lines by inflection? An Argument for it, taken from an Experiment
+made on St. _Paul_'s Steeple._
+
+8. _Whether the distance of the Planets will not be more difficult to be
+found? What wayes are most likely to rectifie the distance of the Moon: the
+way of fitting _Telescopes_ for such Observations. How to make the
+Observations, and how from them to find the true distance of the Moon at
+any time. How the distance of the Sun may be found by two Observators. The
+way by the Dicotomy of the Moon uncertain. That the distance of the Moon
+may be less then it has been hitherto suppos'd. _Kepler_'s Supposition not
+so probable: the explication of the _Phænomena_ by another _Hypothesis_._
+
+Observ. 59. Of the fixt Stars.
+
+_Of the multitudes of Stars discoverable by the _Telescope_, and the
+variety of their magnitudes: 78. Stars distinguisht in the _Pleiades_: that
+there are degrees of bigness even in the Stars accounted of the same
+magnitude: the longer the Glasses are, and the bigger apertures they will
+indure, the more fit they are for these discoveries: that 'tis probable,
+longer Glasses would yet make greater discoveries. 5. Stars discover'd in
+the _Galaxie_ of _Orion_'s Sword._
+
+Observ. 60. Of the Moon.
+
+_A description of a Vale in the Moon; what call'd by _Hevelius_ and
+_Ricciolus_, and how describ'd by them: with what substances the hills of
+the Moon may be cover'd. A description of the pits of the Moon, and a
+conjecture at their cause: two Experiments that make it probable, that of
+the surface of boyl'd Alabaster dust seeming the most likely to be
+resembled by eruptions of vapours out of the body of the Moon: that
+Earthquakes seem to be generated much the same way, and their effects seem
+very similar. An Argument that there may be such variations in the Moon,
+because greater have been observ'd in the Sun: because substance of the
+Moon and Earth seem much alike: and because 'tis probable the Moon has a
+gravitating principle: this is argued from several particulars. The reason
+why several pits are one within another. The use that may be made of this
+Instance of a gravity in the Moon._
+
+       *       *       *       *       *
+
+
+[1] _Schem._ 2. _Fig._ 1.
+
+[2] Diop. ch. 10. § 9.
+
+[3] _Schem._ 2. _Fig._ 2.
+
+[4] _Schem._ 1.* _Fig._ 3.
+
+[5] _Schem._ 3. _Fig._ 1.
+
+[6] _Schem._ 3. _Fig._ 2.
+
+[7] _Schem._ 4.
+
+[8] _Schem._ 4. _Fig._ 1.
+
+[9] _Schem._ 6. _Fig._ 3.
+
+[10] _Schem._ 6. _Fig._ 3.
+
+[11] _Schem._ 8. _Fig._ 1.
+
+[12] _Schem._ 8. _Fig._ 2.
+
+[13] _Schem._ 9. _Fig._ 1.
+
+    [14] See _Schem._ 11. _Fig._ 2.
+
+[15] _Fig._ 1. _Schem._ 36.
+
+[16] _Fig._ 3.
+
+
+
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+<title>The Project Gutenberg eBook of Micrographia, by Robert Hooke</title>
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+<h1>The Project Gutenberg eBook, Micrographia, by Robert Hooke</h1>
+<pre class="pg">
+This eBook is for the use of anyone anywhere at no cost and with
+almost no restrictions whatsoever.  You may copy it, give it away or
+re-use it under the terms of the Project Gutenberg License included
+with this eBook or online at <a href = "https://www.gutenberg.org">www.gutenberg.org</a></pre>
+<p>Title: Micrographia</p>
+<p>       Some Physiological Descriptions of Minute Bodies Made by Magnifying Glasses with Observations and Inquiries Thereupon</p>
+<p>Author: Robert Hooke</p>
+<p>Release Date: March 29, 2005  [eBook #15491]</p>
+<p>Language: English</p>
+<p>Character set encoding: ISO-8859-1</p>
+<p>***START OF THE PROJECT GUTENBERG EBOOK MICROGRAPHIA***</p>
+<p>&nbsp;</p>
+<h3>E-text prepared by Robert Shimmin, Keith Edkins,<br />
+    and the Project Gutenberg Online Distributed Proofreading Team</h3>
+<p>&nbsp;</p>
+<hr class="full" />
+<p>&nbsp;</p>
+<p>&nbsp;</p>
+
+  <div class="figcenter" style="width:60%;">
+      <a href="images/rule-01.png"><img width="100%" src="images/rule-01.png"
+      alt="Decorative rule" /></a>
+  </div>
+  <br clear="all" />
+
+<h2>By the Council of the ROYAL SOCIETY of <i>London</i><br />
+for Improving of Natural Knowledge.</h2>
+
+  <p>Ordered, <i>That the Book written by </i>Robert Hooke<i>, M.A. Fellow
+  of this Society, Entituled, </i>Micrographia, or some Physiological
+  Descriptions of Minute Bodies, made by Magnifying Glasses, with
+  Observations and Inquiries thereupon<i>, Be printed by </i>John
+  Martyn<i>, and </i>James Allestry<i>, Printers to the said
+  Society</i>.</p>
+
+  <p><i>Novem.</i> 23. 1664.</p>
+
+  <p class="author">BROUNCKER. <i>P.R.S.</i></p>
+
+  <div class="figcenter" style="width:60%;">
+      <a href="images/rule-02.png"><img width="100%" src="images/rule-02.png"
+      alt="Decorative rule" /></a>
+  </div>
+  <br clear="all" />
+
+<h1 class="red">MICROGRAPHIA:</h1>
+
+<p class="center">OR SOME</p>
+
+<h3><i>Physiological Descriptions</i></h3>
+
+<p class="center">OF</p>
+
+<h2 class="red">MINUTE BODIES</h2>
+
+<p class="center">MADE BY</p>
+
+<h3 class="red">MAGNIFYING GLASSES</h3>
+
+<p class="center">WITH</p>
+
+<h3><span class="red">OBSERVATIONS</span> and <span class="red">INQUIRIES</span> thereupon.</h3>
+
+  <br clear="all" />
+<hr />
+
+<p class="center">By <i class="red">R. HOOKE</i>, Fellow of the <span class="red">ROYAL SOCIETY</span>.</p>
+
+  <br clear="all" />
+<hr />
+
+  <div class="contents">
+    <div class="stanza">
+      <p><i>Non possis oculo quantum contendere Linceus,</i></p>
+      <p><i>Non tamen idcirco contemnas Lippus inungi.</i> Horat. Ep. lib. 1.</p>
+    </div>
+  </div>
+  <div class="figcenter" style="width:40%;">
+      <a href="images/crest.png"><img width="100%" src="images/crest.png"
+      alt="Arms of the Royal Society" /></a>
+  </div>
+  <br clear="all" />
+<hr class="full" />
+
+<p class="center"><i>LONDON</i>, Printed by <i class="red">Jo. Martyn</i>, and <i class="red">Ja. Allestry</i>, Printers to the
+<span class="red">ROYAL SOCIETY</span>, and are to be sold at their Shop at the <i>Bell</i> in
+<i>S. Paul's</i> Church-yard. <span class="red">M DC LX V</span>.</p>
+
+<hr class="full" />
+
+  <div class="figcenter" style="width:60%;">
+      <a href="images/rule-03.png"><img width="100%" src="images/rule-03.png"
+      alt="Decorative rule" /></a>
+  </div>
+  <br clear="all" />
+
+<h2>TO THE</h2>
+
+<h1>KING.</h1>
+
+  <p><b><i>SIR</i></b>,</p>
+
+  <p><img align="left" src="images/illumined-I.png" alt="I" /> Do here most humbly lay this <i>small</i> Present at <i>Your
+  Majesties</i> Royal feet. And though it comes accompany'd with two
+  <i>disadvantages</i>, the <i>meanness</i> of the <i>Author</i>, and of
+  the <i>Subject</i>; yet in both I am <i>incouraged</i> by the
+  <i>greatness</i> of your <i>Mercy</i> and your <i>Knowledge</i>. By the
+  <i>one</i> I am taught, that you can <i>forgive</i> the most
+  <i>presumptuous Offendors</i>: And by the <i>other</i>, that you will not
+  <i>esteem</i> the least work of <i>Nature</i>, or <i>Art</i>, unworthy
+  your <i>Observation</i>. Amidst the many <i>felicities</i> that have
+  accompani'd <i>your Majesties</i> happy <i>Restauration</i> and
+  <i>Government</i>, it is none of the least considerable that
+  <i>Philosophy</i> and <i>Experimental Learning</i> have <i>prosper'd</i>
+  under your <i>Royal Patronage</i>. And as the calm prosperity of your
+  Reign has given us the <i>leisure</i> to follow these <i>Studies</i> of
+  <i>quiet</i> and <i>retirement</i>, so it is just, that the <i>Fruits</i>
+  of them should, by way of <i>acknowledgement</i>, be return'd to <i>your
+  Majesty</i>. There are, Sir, several other of your Subjects, of your
+  <i>Royal Society</i>, now busie about <i>Nobler</i> matters: The
+  <i>Improvement</i> of <i>Manufactures</i> and <i>Agriculture</i>, the
+  <i>Increase</i> of <i>Commerce</i>, the <i>Advantage</i> of
+  <i>Navigation</i>: In all which they are <i>assisted</i> by <i>your
+  Majesties Incouragement</i> and <i>Example</i>. Amidst all those
+  <i>greater</i> Designs, I here presume to bring in that which is more
+  <i>proportionable</i> to the <i>smalness</i> of my Abilities, and to
+  offer some of the <i>least</i> of all <i>visible things</i>, to that
+  <i>Mighty King</i>, that has <i>establisht an Empire</i> over the best of
+  all <i>Invisible things</i> of this World, the <i>Minds</i> of Men.</p>
+
+<p class="center"><i>Your Majesties most humble<br />
+and most obedient<br />
+Subject and Servant</i>,</p>
+
+<h3>ROBERT HOOKE.</h3>
+
+  <div class="figcenter" style="width:60%;">
+      <a href="images/rule-04.png"><img width="100%" src="images/rule-04.png"
+      alt="Decorative rule" /></a>
+  </div>
+  <br clear="all" />
+
+<h3>TO THE</h3>
+
+<h2>ROYAL SOCIETY.</h2>
+
+  <p>
+  <span title="Word with illuminated initial: After">
+  <img align="left" src="images/illumined-A.png" alt="A" />fter
+  </span>
+  my <i>Address</i> to our <i>Great Founder</i> and <i>Patron</i>,
+  I could not but think my self oblig'd, in consideration of those <i>many
+  Ingagements</i> you have laid upon me, to offer these my <i>poor
+  Labours</i> to this MOST ILLUSTRIOUS ASSEMBLY. YOU have been pleas'd
+  formerly to accept of these rude <i>Draughts</i>. I have since added to
+  them some <i>Descriptions</i>, and some <i>Conjectures</i> of my own. And
+  therefore, together with YOUR <i>Acceptance</i>, I must also beg YOUR
+  <i>pardon</i>. The Rules YOU have prescrib'd YOUR selves in YOUR
+  Philosophical Progress do seem the best that have ever yet been
+  practis'd. And particularly that of avoiding <i>Dogmatizing</i>, and the
+  <i>espousal</i> of any <i>Hypothesis</i> not sufficiently grounded and
+  confirm'd by <i>Experiments</i>. This way seems the most excellent, and
+  may preserve both <i>Philosophy</i> and <i>Natural History</i> from its
+  former <i>Corruptions</i>. In saying which, I may seem to condemn my own
+  Course in this Treatise; in which there may perhaps be some
+  <i>Expressions</i>, which may seem more <i>positive</i> then YOUR
+  Prescriptions will permit: And though I desire to have them understood
+  only as <i>Conjectures</i> and <i>Quæries</i> (which YOUR Method does not
+  altogether disallow) yet if even in those I have exceeded, 'tis fit that
+  I should declare, that it was not done by YOUR Directions. For it is most
+  unreasonable, that YOU should undergo the <i>imputation</i> of the
+  <i>faults</i> of my <i>Conjectures</i>, seeing YOU can receive so
+  <i>small advantage</i> of reputation by the <i>sleight Observations</i>
+  of</p>
+
+<p class="center"><i>YOUR most humble and<br />
+most faithful Servant</i></p>
+
+<h3>ROBERT HOOKE.</h3>
+
+  <div class="figcenter" style="width:60%;">
+      <a href="images/rule-04.png"><img width="100%" src="images/rule-04.png"
+      alt="Decorative rule" /></a>
+  </div>
+  <br clear="all" />
+
+<h3>THE</h3>
+
+<h1>PREFACE.</h1>
+
+  <p><i><span title="Word with illuminated initial: It">
+  <img align="left" src="images/illumined-I.png" alt="I" />t</span>
+  is the great prerogative of Mankind above other Creatures, that
+  we are not only able to </i>behold<i> the works of Nature, or barely to
+  </i>sustein<i> our lives by them, but we have also the power of
+  </i>considering<i>, </i>comparing<i>, </i>altering<i>, </i>assisting<i>,
+  and </i>improving<i> them to various uses. And as this is the peculiar
+  priviledge of humane Nature in general, so is it capable of being so far
+  advanced by the helps of Art, and Experience, as to make some Men excel
+  others in their Observations, and Deductions, almost as much as they do
+  Beasts. By the addition of such </i>artificial Instruments<i> and
+  </i>methods<i>, there may be, in some manner, a reparation made for the
+  mischiefs, and imperfection, mankind has drawn upon it self, by
+  negligence, and intemperance, and a wilful and superstitious deserting
+  the Prescripts and Rules of Nature, whereby every man, both from a
+  deriv'd corruption, innate and born with him, and from his breeding and
+  converse with men, is very subject to slip into all sorts of
+  errors.</i></p>
+
+  <p><i>The only way which now remains for us to recover some degree of
+  those former perfections, seems to be, by rectifying the operations of
+  the </i>Sense<i>, the </i>Memory<i>, and </i>Reason<i>, since upon the
+  evidence, the </i>strength<i>, the </i>integrity<i>, and the </i>right
+  correspondence<i> of all these, all the light, by which our actions are
+  to be guided is to be renewed, and all our command over things it to be
+  establisht.</i></p>
+
+  <p><i>It is therefore most worthy of our consideration, to recollect
+  their several defects, that so we may the better understand how to supply
+  them, and by what assistances we may </i>inlarge<i> their power, and
+  </i>secure<i> them in performing their particular duties.</i></p>
+
+  <p><i>As for the actions of our </i>Senses<i>, we cannot but observe them
+  to be in many particulars much outdone by those of other Creatures, and
+  when at best, to be far short of the perfection they seem capable of: And
+  these infirmities of the Senses arise from a double cause, either from
+  the </i>disproportion of the Object to the Organ<i>, whereby an infinite
+  number of things can never enter into them, or else from </i>error in the
+  Perception<i>, that many things, which come within their reach, are not
+  received in a right manner.</i></p>
+
+  <p><i>The like frailties are to be found in the </i>Memory;<i> we often
+  let many things </i>slip away<i> from us, which deserve to be retain'd,
+  and of those which we treasure up, a great part is either
+  </i>frivolous<i> or </i>false<i>; and if good, and substantial, either in
+  tract of time </i>obliterated<i>, or at best so </i>overwhelmed<i> and
+  buried under more frothy notions, that when there is need of them, they
+  are in vain sought for.</i></p>
+
+  <p><i>The two main foundations being so deceivable, it is no wonder, that
+  all the succeeding works which we build upon them, of arguing,
+  concluding, defining, judging, and all the other degrees of Reason, are
+  lyable to the same imperfection, being, at best, either vain, or
+  uncertain: So that the errors of the </i>understanding<i> are answerable
+  to the two other, being defective both in the quantity and goodness of
+  its knowledge; for the limits, to which our thoughts are confin'd, are
+  small in respect of the vast extent of Nature it self; some parts of it
+  are </i>too large<i> to be comprehended, and some </i>too little<i> to be
+  perceived. And from thence it must follow, that not having a full
+  sensation of the Object, we must be very lame and imperfect in our
+  conceptions about it, and in all the proportions which we build upon it;
+  hence, we often take the </i>shadow<i> of things for the
+  </i>substance<i>, small </i>appearances<i> for good </i>similitudes<i>,
+  </i>similitudes<i> for </i>definitions;<i> and even many of those, which
+  we think, to be the most solid definitions, are rather expressions of our
+  own misguided apprehensions then of the true nature of the things
+  themselves.</i></p>
+
+  <p><i>The effects of these imperfections are manifested in different
+  ways, according to the temper and disposition of the several minds of
+  men, some they incline to </i>gross ignorance<i> and stupidity, and
+  others to a </i>presumptuous imposing<i> on other mens Opinions, and a
+  </i>confident dogmatizing<i> on matters, whereof there it no assurance to
+  be given.</i></p>
+
+  <p><i>Thus all the uncertainty, and mistakes of humane actions, proceed
+  either from the narrowness and wandring of our </i>Senses<i>, from the
+  slipperiness or delusion of our </i>Memory<i>, from the confinement or
+  rashness of our </i>Understanding<i>, so that 'tis no wonder, that our
+  power over natural causes and effects is so slowly improv'd, seeing we
+  are not only to contend with the obscurity and </i>difficulty of the
+  things<i> whereon we work and think, but even the </i>forces of our own
+  minds<i> conspire to betray us.</i></p>
+
+  <p><i>These being the dangers in the process of humane Reason, the
+  remedies of them all can only proceed from the </i>real<i>, the
+  </i>mechanical<i>, the </i>experimental<i> Philosophy, which has this
+  advantage over the Philosophy of </i>discourse<i> and </i>disputation<i>,
+  that whereas that chiefly aims at the subtilty of its Deductions and
+  Conclusions, without much regard to the first ground-work, which ought to
+  be well laid on the Sense and Memory; so this intends the right ordering
+  of them all, and the making them serviceable to each other.</i></p>
+
+  <p><i>The first thing to be undertaken in this weighty work, is a
+  </i>watchfulness over the failings<i> and an </i>inlargement of the
+  dominion<i>, of the Senses.</i></p>
+
+  <p><i>To which end it is requisite, first, That there should be a
+  </i>scrupulous<i> choice, and a </i>strict examination<i>, of the
+  reality, constancy, and certainty of the Particulars that we admit: This
+  is the first rise whereon truth is to begin, and here the most severe,
+  and most impartial diligence, must be imployed; the storing up of all,
+  without any regard to evidence or use, will only tend to darkness and
+  confusion. We must not therefore esteem the riches of our Philosophical
+  treasure by the </i>number<i> only, but chiefly by the </i>weight<i>; the
+  most </i>vulgar<i> Instances are not to be neglected, but above all, the
+  most </i>instructive<i> are to be entertain'd; the footsteps of Nature
+  are to be trac'd, not only in her </i>ordinary course<i>, but when she
+  seems to be put to her shifts, to make many </i>doublings<i> and
+  </i>turnings<i>, and to use some kind of art in indeavouring to avoid our
+  discovery.</i></p>
+
+  <p><i>The next care to be taken, in respect of the Senses, is a supplying
+  of their infirmities with </i>Instruments<i>, and, as it were, the adding
+  of </i>artificial Organs<i> to the </i>natural<i>; this in one of them
+  has been of late years accomplisht with prodigious benefit to all sorts
+  of useful knowledge, by the invention of Optical Glasses. By the means of
+  </i>Telescopes<i>, there is nothing so </i>far distant<i> but may be
+  represented to our view; and by the help of </i>Microscopes<i>, there is
+  nothing so </i>small<i>, as to escape our inquiry; hence there is a new
+  visible World discovered to the understanding. By this means the Heavens
+  are open'd, and a vast number of new Stars, and new Motions, and new
+  Productions appear in them, to which all the ancient Astronomers were
+  utterly Strangers. By this the Earth it self, which lyes so neer us,
+  under our feet, shews quite a new thing to us, and in every </i>little
+  particle<i> of its matter; we now behold almost as great a variety of
+  Creatures, as we were able before to reckon up in the whole
+  </i>Universe<i> it self.</i></p>
+
+  <p><i>It seems not improbable, but that by these helps the subtilty of
+  the composition of Bodies, the structure of their parts, the various
+  texture of their matter, the instruments and manner of their inward
+  motions, and all the other possible appearances of things, may come to be
+  more fully discovered; all which the ancient </i>Peripateticks<i> were
+  content to comprehend in two general and (unless further explain'd)
+  useless words of </i>Matter<i> and </i>Form<i>. From whence there may
+  arise many admirable advantages, towards the increase of the
+  </i>Operative<i>, and the </i>Mechanick<i> Knowledge, to which this Age
+  seems so much inclined, because we may perhaps be inabled to discern all
+  the secret workings of Nature, almost in the same manner as we do those
+  that are the productions of Art, and are manag'd by Wheels, and Engines,
+  and Springs, that were devised by humane Wit.</i></p>
+
+  <p><i>In this kind I here present to the World my imperfect Indeavours;
+  which though they shall prove no other way considerable, yet, I hope,
+  they may be in some measure useful to the main Design of a
+  </i>reformation<i> in Philosophy, if it be only by shewing, that there it
+  not so much requir'd towards it, any strength of </i>Imagination<i>, or
+  exactness of </i>Method<i>, or depth of </i>Contemplation<i> (though the
+  addition of these, where they can be had, must needs produce a much more
+  perfect composure) as a sincere </i>Hand<i>, and a </i>faithful<i> Eye,
+  to examine, and to record, the things themselves as they appear.</i></p>
+
+  <p><i>And I beg my Reader, to let me take the boldness to assure him,
+  that in this present condition of knowledge, a man so qualified, as I
+  have indeavoured to be, only with resolution, and integrity, and plain
+  intentions of imploying his </i>Senses<i> aright, may venture to compare
+  the reality and the usefulness of his services, towards the true
+  Philosophy, with those of other men, that are of much stronger, and more
+  acute </i>speculations<i>, that shall not make use of the same method by
+  the Senses.</i></p>
+
+  <p><i>The truth is, the Science of Nature has been already too long made
+  only a work of the </i>Brain<i> and the </i>Fancy<i>: It is now high time
+  that it should return to the plainness and soundness of
+  </i>Observations<i> on </i>material<i> and </i>obvious<i> things. It is
+  said of great Empires, That </i>the best way to preserve them from decay,
+  is to bring them back to the first Principles, and Arts, on which they
+  did begin<i>. The same is undoubtedly true in Philosophy, that by
+  wandring far away into </i>invisible Notions<i>, has almost quite
+  destroy'd it self, and it can never be recovered, or continued, but by
+  returning into the same </i>sensible paths<i>, in which it did at first
+  proceed.</i></p>
+
+  <p><i>If therefore the Reader expects from me any infallible Deductions,
+  or certainty of </i>Axioms<i>, I am to say for my self, that those
+  stronger Works of Wit and Imagination are above my weak Abilities; or if
+  they had not been so, I would not have made use of them in this present
+  Subject before me: Whenever he finds that I have ventur'd at any small
+  Conjectures, at the causes of the things that I have observed, I beseech
+  him to look, upon them only as </i>doubtful Problems<i>, and
+  </i>uncertain ghesses<i>, and not as unquestionable Conclusions, or
+  matters of unconfutable Science; I have produced nothing here, with
+  intent to bind his understanding to an </i>implicit<i> consent; I am so
+  far from that, that I desire him, not absolutely to rely upon these
+  Observations of my eyes, if he finds them contradicted by the future
+  Ocular Experiments of other and impartial Discoverers.</i></p>
+
+  <p><i>As for my part, I have obtained my end, if these my small Labours
+  shall be thought fit to take up some place in the large stock, of
+  </i>natural Observations<i>, which so many hands are busie in providing.
+  If I have contributed the </i>meanest foundations<i> whereon others may
+  raise nobler </i>Superstructures<i>, I am abundantly satisfied; and all
+  my ambition is, that I may serve to the great Philosophers of this Age,
+  as the makers and the grinders of my Glasses did to me; that I may
+  prepare and furnish them with some </i>Materials<i>, which they may
+  afterwards </i>order<i> and </i>manage<i> with better skill, and to far
+  greater advantage.</i></p>
+
+  <p><i>The next remedies in this universal cure of the Mind are to be
+  applyed to the </i>Memory<i>, and they are to consist of such Directions
+  as may inform us, what things are best to be </i>stor'd up<i> for our
+  purpose, and which is the best way of so </i>disposing<i> them, that they
+  may not only be </i>kept in safety<i>, but ready and convenient, to be at
+  any time </i>produc'd<i> for use, as occasion shall require. But I will
+  not here prevent my self in what I may say in another Discourse, wherein
+  I shall make an attempt to propose some Considerations of the manner of
+  compiling a Natural and Artificial History, and of so ranging and
+  registring its Particulars into Philosophical Tables, as may make them
+  most useful for the raising of </i>Axioms<i> and </i>Theories<i>.</i></p>
+
+  <p><i>The last indeed is the most </i>hazardous<i> Enterprize, and yet
+  the most </i>necessary<i>; and that is, to take such care that the
+  </i>Judgment<i> and the </i>Reason<i> of Man (which is the third Faculty
+  to be repair'd and improv'd) should receive such assistance, as to avoid
+  the dangers to which it it by nature most subject. The Imperfections,
+  which I have already mention'd, to which it is lyable, do either belong
+  to the </i>extent<i>, or the </i>goodness<i> of its knowledge; and here
+  the difficulty is the greater, least that which may be thought a
+  </i>remedy<i> for the one should prove </i>destructive<i> to the other,
+  least by seeking to inlarge our Knowledge, we should render it weak, and
+  uncertain; and least by being too scrupulous and exact about every
+  Circumstance of it, we should confine and streighten it too much.</i></p>
+
+  <p><i>In both these the middle wayes are to be taken, nothing it to
+  be</i> omitted<i>, and yet every thing to pass a </i>mature
+  deliberation<i>: No </i>Intelligence<i> from Men of all Professions, and
+  quarters of the World, to be </i>slighted<i>, and yet all to be so
+  </i>severely examin'd<i>, that there remain no room for doubt or
+  instability; much </i>rigour<i> in admitting, much </i>strictness<i> in
+  comparing, and above all, much </i>slowness<i> in debating, and
+  </i>shyness<i> in determining, is to be practised. The
+  </i>Understanding<i> is to </i>order<i> all the inferiour services of the
+  lower Faculties; but yet it is to do this only as a </i>lawful Master<i>,
+  and not at a </i>Tyrant.<i> It must not </i>incroach<i> upon their
+  Offices, nor take upon it self the employments which belong to either of
+  them. It must </i>watch<i> the irregularities of the Senses, but it must
+  not go before them, or </i>prevent<i> their information. It must
+  </i>examine<i>, </i>range<i>, and </i>dispose<i> of the bank which it
+  laid up in the Memory: but it must be sure to make </i>distinction<i>
+  between the </i>sober<i> and </i>well collected heap<i>, and the
+  </i>extravagant Ideas<i>, and </i>mistaken Images<i>, which there it may
+  sometimes light upon. So many are the </i>links<i>, upon which the true
+  Philosophy depends, of which, if any one be </i>loose<i>, or </i>weak<i>,
+  the whole </i>chain<i> is in danger of being dissolv'd; it is to
+  </i>begin<i> with the Hands and Eyes, and to </i>proceed<i> on through
+  the Memory, to be </i>continued<i> by the Reason; nor is it to stop
+  there, but to </i>come about<i> to the Hands and Eyes again, and so, by a
+  </i>continual passage round<i> from one Faculty to another, it is to be
+  maintained in life and strength, as much as the body of man it by the
+  </i>circulation<i> of the blood through the several parts of the body,
+  the Arms, the Feet, the Lungs, the Heart, and the Head.</i></p>
+
+  <p><i>If once this method were followed with diligence and attention,
+  there is nothing that lyes within the power of human Wit (or which is far
+  more effectual) of human Industry, which we might not compass; we might
+  not only hope for Inventions to equalize those of </i>Copernicus<i>,
+  </i>Galileo<i>, </i>Gilbert<i>, </i>Harvy<i>, and of others, whose Names
+  are almost lost, that were the Inventors of </i>Gun-powder<i>, the
+  </i>Seamans Compass<i>, </i>Printing<i>, </i>Etching<i>, </i>Graving<i>,
+  </i>Microscopes<i>, </i>&amp;c.<i> but multitudes that may far exceed
+  them: for even those discoveries seem to have been the products of some
+  such method, though but imperfect; What may not be therefore expected
+  from it if thoroughly prosecuted? </i>Talking<i> and </i>contention of
+  Arguments<i> would soon be turn'd into </i>labours<i>; all the fine
+  </i>dreams<i> of Opinions, and </i>universal metaphysical natures<i>,
+  which the luxury of subtil Brains has devis'd, would quickly vanish, and
+  give place to </i>solid Histories<i>, </i>Experiments<i> and
+  </i>Works.<i> And as at first, mankind </i>fell<i> by </i>tasting<i> of
+  the forbidden Tree of Knowledge, so we, their Posterity, may be in part
+  </i>restor'd<i> by the same way, not only by </i>beholding<i> and
+  </i>contemplating<i>, but by </i>tasting<i> too those fruits of Natural
+  knowledge, that were never yet forbidden.</i></p>
+
+  <p><i>From hence the World may be assisted with </i>variety<i> of
+  Inventions, </i>new<i> matter for Sciences may be </i>collected<i>, the
+  </i>old improv'd<i>, and their </i>rust<i> rubb'd away; and as it is by
+  the benefit of Senses that we receive all our Skill in the works of
+  Nature, so they also may be wonderfully benefited by it, and may be
+  guided to an easier and more exact performance of their Offices; 'tis not
+  unlikely, but that we may find out wherein our Senses are deficient, and
+  as easily find wayes of repairing them.</i></p>
+
+  <p><i>The Indeavours of Skilful men have been most conversant about the
+  assistance of the Eye, and many noble Productions have followed upon it;
+  and from hence we may conclude, that there it a way open'd for advancing
+  the operations, not only of all the other Senses, but even of the Eye it
+  self; that which has been already done ought not to content us, but
+  rather to incourage us to proceed further, and to attempt greater things
+  in the same, and different wayes.</i></p>
+
+  <p><i>'Tis not unlikely, but that there may be yet invented several other
+  helps for the eye, at much exceeding those already found, as those do the
+  bare eye, such as by which we may perhaps be able to discover </i>living
+  Creatures<i> in the Moon, or other Planets, the </i>figures<i> of the
+  compounding Particles of matter, and the particular </i>Schematisms<i>
+  and </i>Textures<i> of Bodies.</i></p>
+
+  <p><i>And as </i>Glasses<i> have highly promoted our </i>seeing<i>, so
+  'tis not improbable, but that there may be found many </i>Mechanical
+  Inventions<i> to improve our other Senses, of </i>hearing<i>,
+  </i>smelling<i>, </i>tasting<i>, </i>touching.<i> 'Tis not impossible to
+  hear a </i>whisper<i> a </i>furlongs<i> distance, it having been already
+  done; and perhaps the nature of the thing would not make it more
+  impossible, though that furlong should be ten times multiply'd. And
+  though some famous Authors have affirm'd it impossible to hear through
+  the </i>thinnest plate<i> of </i>Muscovy-glass<i>; yet I know a way, by
+  which 'tis easie enough to hear one speak through a </i>wall a yard
+  thick<i>. It has not been yet thoroughly examin'd, how far
+  </i>Otocousticons<i> may be improv'd, nor what other wayes there may be
+  of </i>quickning<i> our hearing, or </i>conveying<i> sound through
+  </i>other bodies<i> then the </i>Air<i>: for that that it not the only
+  </i>medium<i>, I can assure the Reader, that I have, by the help of a
+  </i>distended wire<i>, propagated the sound to a very considerable
+  distance in an </i>instant<i>, or with as seemingly quick a motion as
+  that of light, at least, incomparably swifter then that, which at the
+  same time was propagated through the Air; and this not only in a straight
+  line, or direct, but in one bended in many angles.</i></p>
+
+  <p><i>Nor are the other three so perfect, but that </i>diligence<i>,
+  </i>attention<i>, and many </i>mechanical contrivances<i>, may also
+  highly improve them. For since the sense of </i>smelling<i> seems to be
+  made by the </i>swift passage<i> of the </i>Air<i> (</i>impregnated<i>
+  with the steams and </i>effluvia<i> of several odorous Bodies) through
+  the grisly </i>meanders<i> of the Nose whose surfaces are </i>cover'd<i>
+  with a very sensible </i>nerve<i>, and </i>moistned<i> by a
+  </i>transudation<i> from the </i>processus mamillares<i> of the Brain,
+  and some adjoyning </i>glandules<i>, and by the moist </i>steam<i> of the
+  </i>Lungs<i>, with a Liquor convenient for the reception of those
+  </i>effluvia<i> and by the adhesion and mixing of those steams with that
+  liquor, and thereby affecting the nerve, or perhaps by insinuating
+  themselves into the juices of the brain, after the same manner, as I have
+  in the following Observations intimated, the parts of Salt to pass
+  through the skins of Effs, and Frogs. Since, I say, smelling seems to be
+  made by some such way, 'tis not improbable, but that some contrivance,
+  for making a great quantity of Air pass quick through the Nose, might at
+  much promote the sense of smelling, as the any wayes hindring that
+  passage does dull and destroy it. Several tryals I have made, both of
+  hindring and promoting this sense, and have succeeded in some according
+  to expectation; and indeed to me it seems capable of being improv'd, for
+  the judging of the constitutions of many Bodies. Perhaps we may thereby
+  also judge (as other Creatures seem to do) what is wholsome, what poyson;
+  and in a word, what are the specifick properties of Bodies.</i></p>
+
+  <p><i>There may be also some other mechanical wayes found out, of
+  sensibly perceiving the </i>effluvia<i> of Bodies; several Instances of
+  which, were it here proper, I could give of Mineral steams and
+  exhalations; and it seems not impossible, but that by some such wayes
+  improved, may be discovered, what Minerals lye buried under the Earth,
+  without the trouble to dig for them; some things to confirm this
+  Conjecture may be found in </i>Agricola<i>, and other Writers of
+  Minerals, speaking of the Vegetables that are apt to thrive, or pine, in
+  those steams.</i></p>
+
+  <p><i>Whether also those steams, which seem to issue out of the Earth,
+  and mix with the Air (and so to precipitate some </i>aqueous<i>
+  Exhalations, wherewith 'tis impregnated) may not be by some way detected
+  before they produce the effect, seems hard to determine; yet something of
+  this kind I am able to discover, by an Instrument I contriv'd to shew all
+  the minute variations in the pressure of the Air; by which I constantly
+  find, that before, and during the time of rainy weather, the pressure of
+  the Air is less, and in </i>dry weather<i>, but especially when an
+  </i>Eastern Wind<i> (which having past over vast tracts of Land is heavy
+  with Earthy Particles) blows, it is much more, though these changes are
+  varied according to very odd Laws</i>.</p>
+
+<blockquote>
+  <p>The Instrument is this. I prepare a pretty capaceous Bolt-head AB,
+  with a small stem about two foot and a half long DC; upon the end of this
+  D I put on a small bended Glass, or brazen <i>syphon</i> DEF (open at D,
+  E and F, but to be closed with cement at F and E, as occasion serves)
+  whose stem F should be about six or eight inches long, but the bore of it
+  not above half an inch diameter, and very even; these I fix very strongly
+  together by the help of very hard Cement, and then fit the whole Glass
+  ABCDEF into a long Board, or Frame, in such manner, that almost half the
+  head AB may lye buried in a concave Hemisphere cut into the Board RS;
+<span class="sidenote">
+<a href="images/scheme-01.png" target="_blank" name="prefref"><i>Schem.</i> 1.</a><br /><i>Fig.</i> 1.
+</span>
+  then I place it so on the Board RS, as is exprest in the first figure of
+  the first Scheme; and fix it very firm and steady in that posture, so as
+  that the weight of the <i>Mercury</i> that is afterwards to be put into
+  it, may not in the least shake or stir it; then drawing a line XY on the
+  Frame RT, so that it may divide the ball into two equal parts, or that it
+  may pass, as 'twere, through the center of the ball. I begin from that,
+  and divide all the rest of the Board towards UT into inches, and the
+  inches between the 25 and the end E (which need not be above two or three
+  and thirty inches distant from the line XY) I subdivide into Decimals;
+  then stopping the end F with soft Cement, or soft Wax, I invert the
+  Frame, placing the head downwards, and the Orifice E upwards; and by it,
+  with a small Funnel, I fill the whole Glass with Quicksilver; then by
+  stopping the small Orifice E with my finger, I oftentimes erect and
+  invert the whole Glass and Frame, and thereby free the Quicksilver and
+  Glass from all the bubbles or parcels of lurking Air; then inverting it
+  as before, I fill it top full with clear and well strain'd Quicksilver,
+  and having made ready a small ball of pretty hard Cement, by heat made
+  very soft, I press it into the hole E, and thereby stop it very fast; and
+  to secure this Cement from flying out afterward, I bind over it a piece
+  of Leather, that is spread over in the inside with Cement, and wound
+  about it while the Cement is hot: Having thus softned it, I gently erect
+  again the Glass after this manner: I first let the Frame down edge-wayes,
+  till the edge RV touch the Floor, or ly horizontal; and then in that
+  edging posture raise the end RS; this I do, that if there chance to be
+  any Air hidden in the small Pipe E, it may ascend into the Pipe F, and
+  not into the Pipe DC: Having thus erected it, and hung it by the hole Q,
+  or fixt it perpendicularly by any other means, I open the end F, and by a
+  small <i>Syphon</i> I draw out the <i>Mercury</i> so long, till I find
+  the surface of it AB in the head to touch exactly the line XY; at which
+  time I immediately take away the <i>Syphon</i>, and if by chance it be
+  run somewhat below the line XY, by pouring in gently a little
+  <i>Mercury</i> at F, I raise it again to its desired height, by this
+  contrivance I make all the sensible rising and falling of the
+  <i>Mercury</i> to be visible in the surface of the <i>Mercury</i> in the
+  Pipe F, and scarce any in the head AB. But because there really is some
+  small change of the upper surface also, I find by several Observations
+  how much it rises in the Ball, and falls in the Pipe F, to make the
+  distance between the two surfaces an inch greater then it was before; and
+  the measure that it falls in the Pipe is the length of the inch by which
+  I am to mark the parts of the Tube F, or the Board on which it lyes, into
+  inches and Decimals: Having thus justned and divided it, I have a large
+  Wheel MNOP, whose outmost limb is divided into two hundred equal parts;
+  this by certain small Pillars is fixt on the Frame RT, in the manner
+  exprest in the Figure. In the middle of this, on the back side, in a
+  convenient frame, is placed a small Cylinder, whose circumference is
+  equal to twice the length of one of those divisions, which I find answer
+  to an inch of ascent, or descent, of <i>Mercury</i>: This Cylinder I, is
+  movable on a very small Needle, on the end of which is fixt a very light
+  Index KL, all which are so pois'd on the Axis, or Needle, that no part is
+  heavier then another: Then about this Cylinder is wound a small Clew of
+  Silk, with two small steel Bullets at each end of it GH; one of these,
+  which is somewhat the heavier, ought to be so big, as freely to move to
+  and fro in the Pipe F; by means of which contrivance, every the least
+  variation of the height of the <i>Mercury</i> will be made exceeding
+  visible by the motion to and fro of the small Index KL.</p>
+
+</blockquote>
+
+  <p><i>But this is but one way of discovering the </i>effluvia<i> of the
+  Earth mixt with the Air; there may be, perhaps many others, witness the
+  </i>Hygroscope<i>, an Instrument whereby the watery steams volatile in
+  the Air are discerned, which the Nose it self is not able to find. This I
+  have describ'd in the following Tract in the Description of the Beard of
+  a wild Oat. Others there, are, may be discovered both by the Nose, and by
+  other wayes also. Thus the </i>smoak<i> of burning </i>Wood<i> is
+  </i>smelt<i>, </i>seen<i>, and sufficiently </i>felt<i> by the eyes: The
+  </i>fumes<i> of burning </i>Brimstone<i> are </i>smelt<i> and discovered
+  also by the destroying the Colours of Bodies, as by the </i>whitening of
+  a red Rose<i>: And who knows, but that the Industry of man, following
+  this method, may find out wayes of improving this sense to as great a
+  degree of perfection at it is in any Animal, and perhaps yet
+  higher.</i></p>
+
+  <p><i>'Tis not improbable also, but that our </i>taste<i> may be very
+  much improv'd either by </i>preparing<i> our taste for the Body, as,
+  after eating </i>bitter<i> things, </i>Wine<i>, or other </i>Vinous
+  liquors<i>, are more sensibly tasted; or else by </i>preparing<i> Bodies
+  for our tast; as the dissolving of Metals with acid Liquors, make them
+  tastable, which were before altogether insipid; thus </i>Lead<i> becomes
+  </i>sweeter<i> then Sugar, and </i>Silver<i> more </i>bitter<i> then
+  Gall, </i>Copper<i> and </i>Iron<i> of most </i>loathsome<i> tasts. And
+  indeed the business of this sense being to discover the presence of
+  dissolved Bodies in Liquors put on the Tongue, or in general to discover
+  that a fluid body has some solid body dissolv'd in it, and what they are;
+  whatever contrivance makes this discovery improves this sense. In this
+  kind the mixtures of Chymical Liquors afford many Instances; as the sweet
+  Vinegar that is impregnated with Lead may be discovered to be so by the
+  affusion of a little of an </i>Alcalizate solution<i>: The bitter liquor
+  of </i>Aqua fortis<i> and </i>Silver<i> may be discover'd to be charg'd
+  with that Metal, by laying in it some plates of Copper: 'Tis not
+  improbable also, but there may be multitudes of other wayes of
+  discovering the parts dissolv'd, or dissoluble in liquors; and what is
+  this discovery but a kind of </i>secundary tasting<i>.</i></p>
+
+  <p><i>'Tis not improbable also, but that the sense of </i>feeling<i> may
+  be highly improv'd, for that being a sense that judges of the more
+  </i>gross<i> and </i>robust motions<i> of the </i>Particles<i> of
+  </i>Bodies<i>, seems capable of being improv'd and assisted very many
+  wayes. Thus for the distinguishing of </i>Heat<i> and </i>Cold<i>, the
+  </i>Weather-glass<i> and </i>Thermometer<i>, which I have describ'd in
+  this following Treatise, do exceedingly perfect it; by each of which the
+  least variations of heat or cold, which the most Acute sense is not able
+  to distinguish, are manifested. This is oftentimes further promoted also
+  by the help of </i>Burning-glasses<i>, and the like, which collect and
+  unite the radiating heat. Thus the </i>roughness<i> and </i>smoothness<i>
+  of a Body is made much more sensible by the help of a </i>Microscope<i>,
+  then by the most </i>tender<i> and </i>delicate Hand<i>. Perhaps, a
+  Physitian might, by several other </i>tangible<i> proprieties, discover
+  the constitution of a Body as well as by the </i>Pulse<i>. I do but
+  instance in these, to shew what possibility there may be of many others,
+  and what probability and hopes there were of finding them, if this method
+  were followed; for the Offices of the five Senses being to detect either
+  the </i>subtil<i> and </i>curious Motions<i> propagated through all
+  </i>pellucid<i> or perfectly </i>homogeneous<i> Bodies; Or the more
+  </i>gross<i> and </i>vibrative Pulse<i> communicated through the
+  </i>Air<i> and all other convenient </i>mediums<i>, whether fluid or
+  solid: Or the </i>effluvia<i> of Bodies </i>dissolv'd<i> in the
+  </i>Air<i>; Or the </i>particles<i> of bodies </i>dissolv'd<i> or
+  </i>dissoluble<i> in </i>Liquors<i>, or the more </i>quick<i> and
+  </i>violent shaking motion<i> of </i>heat<i> in all or any of these:
+  whatsoever does any wayes promote any of these kinds of </i>criteria<i>,
+  does afford a way of improving some one sense. And what a multitude of
+  these would a diligent Man meet with in his inquiries? And this for the
+  helping and promoting the </i>sensitive faculty<i> only.</i></p>
+
+  <p><i>Next, as for the </i>Memory<i>, or </i>retentive faculty<i>, we may
+  be sufficiently instructed from the </i>written Histories<i> of </i>civil
+  actions<i>, what great assistance may be afforded the Memory, in the
+  committing to writing things observable in </i>natural operations<i>. If
+  a Physitian be therefore accounted the more able in his Faculty, because
+  he has had long experience and practice, the remembrance of which, though
+  perhaps very imperfect, does regulate all his after actions: What ought
+  to be thought of that man, that has not only a perfect </i>register<i> of
+  his own experience, but it grown </i>old<i> with the experience of many
+  hundreds of years, and many thousands of men.</i></p>
+
+  <p><i>And though of late, men, beginning to be sensible of this
+  convenience, have here and there registred and printed some few
+  </i>Centuries<i>, yet for the most part they are set down very lamely and
+  imperfectly, and, I fear, many times not so truly, they seeming, several
+  of them, to be design'd more for </i>Ostentation<i> then </i>publique
+  use<i>: For, not to instance, that they do, for the most part, omit those
+  Experiences they have made, wherein their Patients have miscarried, it is
+  very easie to be perceiv'd, that they do all along </i>hyperbolically
+  extol<i> their own Prescriptions, and vilifie those of others.
+  Notwithstanding all which, these kinds of Histories are generally
+  esteem'd useful, even to the ablest Physitian.</i></p>
+
+  <p><i>What may not be expected from the </i>rational<i> or </i>deductive
+  Faculty<i> that is furnisht with such </i>Materials<i>, and those so
+  readily </i>adapted<i>, and rang'd for use, that in a moment, at 'twere,
+  thousands of Instances, serving for the </i>illustration<i>,
+  </i>determination<i>, or </i>invention<i>, of almost any inquiry, may be
+  </i>represented<i> even to the sight? How neer the nature of
+  </i>Axioms<i> must all those </i>Propositions<i> be which are examin'd
+  before so many </i>Witnesses<i>? And how difficult will it be for any,
+  though never so subtil an error in Philosophy, to </i>scape<i> from being
+  discover'd, after it has indur'd the </i>touch<i>, and so many other
+  </i>tryals<i>?</i></p>
+
+  <p><i>What kind of mechanical way, and physical invention also is there
+  requir'd that might not this may be found out? The </i>Invention<i> of a
+  way to find the </i>Longitude<i> of places is easily perform'd, and that
+  to as great </i>perfection<i> as is desir'd, or to at great an
+  </i>accurateness<i> as the </i>Latitude<i> of places can be found at Sea;
+  and perhaps yet also to a greater certainty then that has been hitherto
+  found, as I shall very speedily freely manifest to the world. The way of
+  </i>flying<i> in the Air seems principally unpracticable, by reason of
+  the </i>want of strength<i> in </i>humane muscles<i>; if therefore that
+  could be suppli'd, it were, I think, easie to make twenty contrivances to
+  perform the office of </i>Wings<i>: What Attempts also I have made for
+  the supplying that Defect, and my successes therein, which, I think, are
+  wholly new, and not inconsiderable, I shall in another place
+  relate.</i></p>
+
+  <p><i>'Tis not unlikely also, but that </i>Chymists<i>, if they followed
+  this method, might find out their so much sought for </i>Alkahest<i>.
+  What an </i>universal Menstruum<i>, which dissolves all sorts of
+  </i>Sulphureous Bodies<i>, I have discover'd (which hat not been before
+  taken notice of as such) I have shewn in the sixteenth
+  Observation.</i></p>
+
+  <p><i>What a prodigious variety of Inventions in </i>Anatomy<i> has this
+  latter Age afforded, even in our own Bodies in the very </i>Heart<i>, by
+  which we live, and the Brain, which is the seat of our knowledge of other
+  things? witness all the excellent Works of </i>Pecquet<i>,
+  </i>Bartholinus<i>, </i>Billius<i>, and many others; and at home, of
+  Doctor </i>Harvy<i>, Doctor </i>Ent<i>, Doctor </i>Willis<i>, Doctor
+  </i>Glisson<i>. In </i>Celestial Observations<i> we have far exceeded all
+  the Antients, even the </i>Chaldeans<i> and </i>Egyptians<i> themselves,
+  whose </i>vast Plains<i>, </i>high Towers<i>, and </i>clear Air<i>, did
+  not give them so great advantages over us, as have over them by our
+  </i>Glasses<i>. By the help of which, they have been very much outdone by
+  the famous </i>Galileo<i>, </i>Hevelius<i>, </i>Zulichem<i>; and our own
+  Countrymen, Mr. </i>Rook<i>, Doctor </i>Wren<i>, and the great Ornament
+  of our Church and Nation, the </i>Lord Bishop of Exeter<i>. And to say no
+  more in </i>Aerial Discoveries<i>, there has been a wonderful progress
+  made by the </i>Noble Engine<i> of </i>the most Illustrious Mr. Boyle<i>,
+  whom it becomes me to mention with all honour, not only as my particular
+  Patron, but as the </i>Patron<i> of </i>Philosophy<i> it self; which he
+  every day </i>increases<i> by his </i>Labours<i>, and </i>adorns<i> by
+  his </i>Example<i>.</i></p>
+
+  <p><i>The good success of all these </i>great Men<i>, and many others,
+  and the now seemingly great </i>obviousness<i> of most of their and
+  divers other Inventions, which from the beginning of the world have been,
+  as 'twere, trod on, and yet not minded till these last </i>inquisitive<i>
+  Ages (an Argument that there may be yet behind multitudes of the like)
+  puts me in mind to recommend such Studies, and the prosecution of them by
+  such methods, to the </i>Gentlemen<i> of our Nation, whose </i>leisure<i>
+  makes them fit to </i>undertake<i>, and the </i>plenty<i> of their
+  fortunes </i>to accomplish<i>, extraordinary things in this way. And I do
+  not only propose this kind of </i>Experimental Philosophy<i> as matter of
+  high </i>rapture<i> and </i>delight<i> of the mind, but even as a
+  </i>material<i> and </i>sensible Pleasure<i>. So vast it the </i>variety
+  of Objects<i> which will come under their Inflections, so many
+  </i>different wayes<i> there are </i>of handling<i> them, so great is the
+  </i>satisfaction<i> of </i>finding<i> out </i>new things<i>, that I dare
+  compare the </i>contentment<i> which they will injoy, not only to that of
+  </i>contemplation<i>, but even to that which most men prefer of </i>the
+  very Senses themselves<i>.</i></p>
+
+  <p><i>And if they will please to take any incouragement from so mean and
+  so imperfect endeavours as mine, upon my own experience, I can assure
+  them, without arrogance, That there has not been any inquiry or Problem
+  in </i>Mechanicks<i>, that I have hitherto propounded to my self, but by
+  a certain method (which I may on some other opportunity explain) I have
+  been able presently to examine the possibility of it; and if so, as
+  easily to excogitate divers wayes of performing it: And indeed it is
+  possible to do as much by </i>this method<i> in </i>Mechanicks<i>, as by
+  </i>Algebra<i> can be perform'd in </i>Geometry<i>. Nor can I at all
+  doubt, but that the same method is as applicable to </i>Physical
+  Enquiries<i>, and as likely to find and reap thence at plentiful a crop
+  of Inventions; and indeed there seems to be no subject so barren, but may
+  with this good husbandry be highly improv'd.</i></p>
+
+  <p><i>Toward the prosecution of this method in </i>Physical Inquiries<i>,
+  I have here and there </i>gleaned<i> up an </i>handful<i> of
+  Observations, in the collection of most of which I made use of
+  </i>Microscopes<i>, and some other </i>Glasses<i> and </i>Instruments<i>
+  that improve the sense; which way I have herein taken, not that there are
+  not multitudes of useful and pleasant Observables, yet uncollected,
+  obvious enough without the helps of Art, but only to promote the use of
+  Mechanical helps for the Senses, both in the surveying the already
+  visible World, and for the discovery of many others hitherto unknown, and
+  to make us, with the great Conqueror, to be affected that we have not yet
+  overcome one World when there are so many others to be discovered, every
+  considerable improvement of </i>Telescopes<i> or </i>Microscopes<i>
+  producing new Worlds and </i>Terra-Incognita's<i> to our view.</i></p>
+
+  <p><i>The Glasses I used were of our English make, but though very good
+  of the kind, yet far short of what might be expected, could we once find
+  a way of making Glasses Elliptical, or of some more true shape; for
+  though both </i>Microscopes<i>, and </i>Telescopes<i>, as they now are,
+  will magnifie an Object about a thousand thousand times bigger then it
+  appears to the naked eye; yet the Apertures of the Object-glasses are so
+  very small, that very few Rays are admitted, and even of those few there
+  are so many false, that the Object appears </i>dark<i> and
+  </i>indistinct<i>: And indeed these inconveniences are such, as seem
+  inseparable from Spherical Glasses, even when most exactly made; but the
+  way we have hitherto made use of for that purpose is so imperfect, that
+  there may be perhaps ten wrought before one be made tolerably good, and
+  most of those ten perhaps every one differing in goodness one from
+  another, which is an Argument, that the way hitherto used is, at least,
+  very uncertain. So that these Glasses have a double defect; the one, that
+  very few of them are exactly true wrought; the other, that even of those
+  that are best among them, none will admit a sufficient number of Rayes to
+  magnifie the Object beyond a determinate bigness. Against which
+  Inconveniences the only Remedies I have hitherto met with are
+  these.</i></p>
+
+<blockquote>
+  <p>First, for <i>Microscopes</i> (where the Object we view is near and
+  within our power) the best way of making it appear bright in the Glass,
+  is to cast a great quantity of light on it by means of <i>convex
+  glasses</i>, for thereby, though the aperture be very small, yet there
+  will throng in through it such multitudes, that an Object will by this
+  means indure to be magnifi'd as much again as it would be without it. The
+  way for doing which is this. I make choice of some Room that has only one
+  window open to the South, and at about three or four foot distance from
+  this Window, on a Table, I place my <i>Microscope</i>, and then so place
+  either a round Globe of Water, or a very deep clear<i> plano convex</i>
+  Glass (whose convex side is turn'd towards the Window) that there is a
+  great quantity of Rayes collected and thrown upon the Object: Or if the
+  Sun shine, I place a small piece of oyly Paper very near the Object,
+  between that and the light; then with a good large Burning-Glass I so
+  collect and throw the Rayes on the Paper, that there may be a very great
+  quantity of light pass through it to the Object; yet I so proportion that
+  light, that it may not singe or burn the Paper. Instead of which Paper
+  there may be made use of a small piece of Looking-glass plate, one of
+  whose sides is made rough by being rubb'd on a flat Tool with very find
+  sand, this will, if the heat be leisurely cast on it, indure a much
+  greater degree of heat, and consequently very much augment a convenient
+  light. By all which means the light of the Sun, or of a Window, may be so
+  cast on an Object, as to make it twice as light as it would otherwise be
+  without it, and that without any inconvenience of glaring, which the
+  immediate light of the Sun is very apt to create in most Objects; for by
+  this means the light is so equally diffused, that all parts are alike
+  inlightned; but when the immediate light of the Sun falls on it, the
+  reflexions from some few parts are so vivid, that they drown the
+  appearance of all the other, and are themselves also, by reason of the
+  inequality of light, indistinct, and appear only radiant spots.</p>
+
+  <p>But because the light of the Sun, and also that of a Window, is in a
+  continual variation, and so many Objects cannot be view'd long enough by
+  them to be throughly examin'd; besides that, oftentimes the Weather is so
+  dark and cloudy, that for many dayes together nothing can be view'd: And
+  because also there are many Objects to be met with in the night, which
+  cannot so conveniently be kept perhaps till the day, therefore to procure
+  and cast a sufficient quantity of light on an Object in the night, I
+  thought of, and often used this, Expedient.</p>
+
+<span class="sidenote">
+<a href="images/scheme-01.png" target="_blank"><i>Schem.</i> 1.</a><br /><i>Fig.</i> 5.
+</span>
+  <p>I procur'd me a small Pedestal, such as is describ'd in the fifth
+  Figure of the first <i>Scheme</i> on the small Pillar AB, of which were
+  two movable Armes CD, which by means of the Screws EF, I could fix in any
+  part of the Pillar; on the undermost of these I plac'd a pretty large
+  Globe of Glass G, fill'd with exceeding clear Brine, stopt, inverted, and
+  fixt in the manner visible in the Figure; out of the side of which Arm
+  proceeded another Arm H, with many joynts; to the end of which was
+  fastned a deep plain <i>Convex glass</i> I, which by means of this Arm
+  could be moved too and fro, and fixt in any posture. On the upper Arm was
+  placed a small Lamp K, which could be to mov'd upon the end of the Arm,
+  as to be set in a fit posture to give light through the Ball: By means of
+  this Instrument duly plac'd, as is exprest in the Figure, with the small
+  flame of a Lamp may be cast as great and convenient a light on the Object
+  as it will well indure; and being always constant, and to be had at any
+  time, I found most proper for drawing the representations of those small
+  Objects I had occasion to observe.</p>
+
+  <p>None of all which ways (though much beyond any other hitherto made use
+  of by any I know) do afford a sufficient help, but after a certain degree
+  of magnifying, they leave us again in the lurch. Hence it were very
+  desirable, that some way were thought of for making the Object-glass of
+  such a Figure as would conveniently bear a large Aperture.</p>
+
+</blockquote>
+
+  <p><i>As for </i>Telescopes<i>, the only improvement they seem capable
+  of, is the increasing of their length; for the Object being remote, there
+  is no thought of giving it a greater light then it has; and therefore to
+  augment the. Aperture, the Glass must be ground of a very large sphere;
+  for, by that means, the longer the Glass be, the bigger aperture will it
+  bear, if the Glasses be of an equal goodness in their kind. Therefore a
+  six will indure a much larger Aperture then a three foot Glass, and a
+  sixty foot Glass will proportionably bear a greater Aperture then a
+  thirty, and will as much excel it also as a six foot does a three foot,
+  as I have experimentally observ'd in one of that length made by Mr.
+  </i>Richard Reives<i> here at </i>London<i>, which will bear an Aperture
+  above three inches over, and yet make the Object proportionably big and
+  distinct; whereas there are very few thirty foot Glasses that will indure
+  an Aperture of more then two inches over. So that for </i>Telescopes<i>,
+  supposing we had a very ready way of making their Object Glasses of
+  exactly spherical Surfaces, we might, by increasing the length of the
+  Glass, magnifie the Object to any assignable bigness. And for performing
+  both these, I cannot imagine any way more easie, and more exact, then by
+  this following Engine, by means of which, any Glasses, of what length
+  soever, may be speedily made. It seems the most easie, because with one
+  and the same Tool may be with care ground an Object Glass, of any length
+  or breadth requisite, and that with very little or no trouble in fitting
+  the Engine, and without much skill in the Grinder. It seems to be the
+  most exact, for to the very last stroke the Glass does regulate and
+  rectifie the Tool to its exact Figure; and the longer or more the Tool
+  and Glass are wrought together, the more exact will both of them be of
+  the desir'd Figure. Further, the motions of the Glass and Tool do so
+  cross each other, that there is not one point of eithers Surface, but has
+  thousands of cross motions thwarting it, so that there can be no kind of
+  Rings or Gutters made either in the Tool or Glass.</i></p>
+
+<blockquote>
+  <p>The contrivance of the Engine is, only to make the ends of two large
+  <i>Mandrils</i> so to move, that the Centers of them may be at any
+  convenient distance asunder, and that the <i>Axis</i> of the
+  <i>Mandrils</i> lying both in the same plain produc'd, may meet each
+  other in any assignable Angle; both which requisites may be very well
+<span class="sidenote">
+<a href="images/scheme-01.png" target="_blank"><i>Schem.</i> 1.</a><br /><i>Fig.</i> 3.
+</span>
+  perform'd by the Engine describ'd in the third Figure of the first
+  <i>Scheme</i>: where AB signifies the Beam of a Lath fixt perpendicularly
+  or Horizontally, CD the two Poppet heads, fixt at about two foot
+  distance, EF an Iron <i>Mandril</i>, whose tapering neck F runs in an
+  adapted tapering brass Collar; the other end E runs on the point of a
+  Screw G; in a convenient place of this is fastned H a pully Wheel, and
+  into the end of it, that comes through the Poppet head C, is screwed a
+  Ring of a hollow <i>Cylinder</i> K, or some other conveniently shap'd
+  Tool, of what wideness shall be thought most proper for the cize of
+  Glasses, about which it is to be imploy'd: As, for Object glasses,
+  between twelve foot and an hundred foot long, the Ring may be about six
+  inches over, or indeed somewhat more for those longer Glasses. It would
+  be convenient also and not very chargeable, to have four or five several
+  Tools; as one for all Glasses between an inch and a foot, one for all
+  Glasses between a foot and ten foot long, another for all between ten and
+  an hundred, a fourth for all between a hundred and a thousand foot long;
+  and if Curiosity shall ever proceed so far, one for all lengths between a
+  thousand and ten thousand foot long; for indeed the principle is such,
+  that supposing the <i>Mandrils</i> well made, and of a good length, and
+  supposing great care be used in working and polishing them, I see no
+  reason, but that a Glass of a thousand, nay of ten thousand foot long,
+  may be as well made as one of ten; for the reason is the same, supposing
+  the <i>Mandrils</i> and Tools be made sufficiently strong, so that they
+  cannot bend; and supposing the Glass, out of which they are wrought, be
+  capable of so great a regularity in its parts as to refraction: this
+  hollow <i>Cylinder</i> K is to contain the Sand, and by being drove round
+  very quick to and fro by means of a small Wheel, which may be mov'd with
+  ones foot, serves to grind the Glass: The other <i>Mandril</i> is shap'd
+  like this, but it has an even neck instead of a taper one, and runs in a
+  Collar, that by the help of a Screw and a joynt made like M in the
+  Figure, it can be still adjustned to the wearing or wasting neck: into
+  the end of this <i>Mandril</i> is screwed a Chock N on which with Cement
+  or Glew is fastned the piece of Glass Q that is to be form'd; the middle
+  of which Glass is to be plac'd just on the edge of the Ring and the Lath
+  OP is to be set and fixt (by means of certain pieces and screws the
+  manner whereof will be sufficiently evidenc'd by the Figure) in such an
+  Angle as is requisite to the forming of such a Sphere as the Glass is
+  design'd to be of; the geometrical ground of which being sufficiently
+  plain, though not heeded before, I shall, for brevities sake, pass over.
+  This last <i>Mandril</i> to be made (by means of the former, or some
+  other Wheel) to run round very swift also, by which two cross motions the
+  Glass cannot chuse (if care be us'd) but be wrought into a most exactly
+  spherical Surface.</p>
+
+</blockquote>
+
+  <p><i>But because we are certain, from the </i>Laws of refraction<i>
+  (which I I have experimentally found to be so, by an Instrument I shall
+  presently describe) that </i>the lines of the angles of Incidence are
+  proportionate to the lines of the angles of Refraction<i>, therefore if
+  Glasses could be made of those kind of Figures, or some other, such as
+  the most incomparable </i>Des Cartes<i> has invented, and demonstrated in
+  his Philosophical and Mathematical Works, we might hope for a much
+  greater perfection of Opticks then can be rationally expected from
+  spherical ones; for though, </i>cæteris paribus<i>, we find, that the
+  larger the </i>Telescope<i> Object Glasses are, and the shorter those of
+  the </i>Microscope<i>, the better they magnify, yet both of them, beside
+  such determinate dimensions, are by certain inconveniences rendred
+  unuseful; for it will be exceeding </i>difficult<i> to make and
+  </i>manage<i> a Tube above an </i>hundred foot long<i>, and it will be as
+  difficult to </i>inlighten<i> an Object less then an hundred part of an
+  inch distant from the Object Glass.</i></p>
+
+  <p><i>I have not as yet made any attempts of that kind, though I know two
+  or three wayes, which, as far as I have yet considered, seem very
+  probable, and may invite me to make a tryal as soon as I have an
+  opportunity, of which I may hereafter perhaps acquaint the world. In the
+  Interim, I shall describe the Instrument I even now mention'd, by which
+  the </i>refraction<i> of all kinds of Liquors may be most exactly
+  measur'd, thereby to give the curious an opportunity of making what
+  further tryals of that kind they shall think requisite to any of their
+  intended tryals; and to let them see that the laws of Refraction are not
+  only notional.</i></p>
+
+<blockquote>
+<span class="sidenote">
+<a href="images/scheme-01.png" target="_blank"><i>Schem.</i> 1.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>The Instrument consisted of five Rulers, or long pieces placed
+  together, after the manner exprest in the second Figure of the first
+  <i>Scheme</i>, where AB denotes a straight piece of wood about six foot
+  and two inches long, about three inches over, and an inch and half thick,
+  on the back side of which was hung a small plummet by a line stretcht
+  from top to bottom, by which this piece was set exactly upright, and so
+  very firmly fixt; in the middle of this was made a hole or center, into
+  which one end of a hollow cylindrical brass Box CC, fashion'd as I shall
+  by and by describe, was plac'd, and could very easily and truly be mov'd
+  to and fro; the other end of this Box being put into, and moving in, a
+  hole made in a small arm DD; into this box was fastned the long Ruler EF,
+  about three foot and three or four inches long, and at three foot from
+  the above mention'd Centers PP was a hole E, cut through, and cross'd
+  with two small threads, and at the end of it was fixt a small sight G,
+  and on the back side of it was fixt a small Arm H, with a Screw to fix it
+  in any place on the Ruler LM; this Ruler LM was mov'd on the Center B
+  (which was exactly three foot distance from the middle Center P) and a
+  line drawn through the middle of it LM, was divided by a Line of cords
+  into some sixty degrees, and each degree was subdivided into minutes, so
+  that putting the cross of the threads in E upon any part of this divided
+  line, I presently knew what Angle the two Rules AB and EF made with each
+  other, and by turning the Screw in H, I could fix them in any position.
+  The other Ruler also RS was made much after the same manner, only it was
+  not fixt to the hollow cylindrical Box, but, by means of two small brass
+  Armes or Ears, it mov'd on the Centers of it; this also, by means of the
+  cross threads in the hole S, and by a Screw in K, could be fastned on any
+  division of another line of cords of the same radius drawn on NO. And so
+  by that means, the Angle made by the two Rulers, AB and RS, was also
+  known. The Brass box CC in the middle was shap'd very much like the
+  Figure X, that is, it was a cylindrical Box stopp'd close at either end,
+  off of which a part both of the sides and bottomes was cut out, so that
+  the Box, when the Pipe and that was joyned to it, would contain the Water
+  when fill'd half full, and would likewise, without running over, indure
+  to be inclin'd to an Angle, equal to that of the greatest refraction of
+  Water, and no more, without running over. The Ruler EF was fixt very fast
+  to the Pipe V, so that the Pipe V directed the length of the Ruler EF,
+  and the Box and Ruler were mov'd on the Pin TT, so as to make any
+  desirable Angle with the Ruler AB. The bottom of this Pipe V was stop'd
+  with a small piece of exactly plain Glass, which was plac'd exactly
+  perpendicular to the Line of direction, or <i>Axis</i> of the Ruler EF.
+  The Pins also TT were drill'd with small holes through the <i>Axis</i>,
+  and through those holes was stretcht and fastned a small Wire. There was
+  likewise a small Pipe of Tin loosly put on upon the end of V, and
+  reaching down to the sight G; the use of which was only to keep any false
+  Rayes of light from passing through the bottom of V, and only admitting
+  such to pass as pierced through the sight G: All things being placed
+  together in the manner describ'd in the Figure; that is, the Ruler AB
+  being fixt perpendicular, I fill'd the Box CC with Water, or any other
+  Liquor, whose refraction I intended to try, till the Wire passing through
+  the middle of it were just covered: then I moved and fixt the Ruler FE at
+  any assignable Angle, and placed the flame of a Candle just against the
+  sight G; and looking through the sight I, I moved the Ruler RS to and
+  fro, till I perceived the light passing through G to be covered, as
+  'twere, or divided by the dark Wire passing through PP: then turning the
+  Screw in K, I fixt it in that posture: And through the hole S, I observed
+  what degree and part of it was cut by the cross threads in S. And this
+  gave me the Angle of Inclination, APS answering to the Angle of
+  Refraction BPE: for the surface of the Liquor in the Box will be alwayes
+  horizontal, and consequently AB will be a perpendicular to it; the Angle
+  therefore APS will measure, or be the Angle of Inclination in the Liquor;
+  next EPB must be the Angle of Refraction, for the Ray that passes through
+  the sight G, passes also perpendicularly through the Glass
+  <i>Diaphragme</i> at F, and consequently also perpendicularly through the
+  lower surface of the Liquor contiguous to the Glass, and therefore
+  suffers no refraction till it meet with the horizontal surface of the
+  Liquor in CC, which is determined by the two Angles.</p>
+
+</blockquote>
+
+  <p><i>By means of this Instrument I can with </i>little trouble<i>, and a
+  very small quantity of any </i>Liquor<i>, examine, most accurately, the
+  </i>refraction<i> of it not only for one inclination, but for all; and
+  thereby am inabled to make very accurate Tables; several of which I have
+  also experimentally made, and find, that </i>Oyl of Turpentine<i> has a
+  much greater Refraction then </i>Spirit of Wine<i>, though it be
+  </i>lighter<i>; and that </i>Spirit of Wine<i> has a greater Refraction
+  then </i>Water<i>, though it be lighter also; but that </i>salt Water<i>
+  also has a greater Refraction then </i>fresh<i>, though it be
+  </i>heavier<i>: but </i>Allum water<i> has a less refraction then common
+  </i>Water<i>, though heavier also. So that it seems, as to the
+  </i>refraction<i> made in a Liquor, the </i>specifick gravity<i> is of no
+  efficacy. By this I have also found that look what </i>proportion <i>the
+  </i>Sine<i> of the Angle of </i>one Inclination<i> has to the </i>Sine<i>
+  of the Angle of </i>Refraction<i>, correspondent to it, the same
+  </i>proportion<i> have all the </i>Sines<i> of other Inclinations to the
+  </i>Sines<i> of their appropriate Refractions.</i></p>
+
+<blockquote>
+  <p>My way for measuring how much a Glass magnifies an Object, plac'd at a
+  convenient distance from my eye, is this. Having rectifi'd the
+  <i>Microscope</i>, to see the desir'd Object through it very distinctly,
+  at the same time that I look upon the Object through the Glass with one
+  eye, I look upon other Objects at the same distance with my other bare
+  eye; by which means I am able, by the help of a <i>Ruler</i> divided into
+  inches and small parts, and laid on the <i>Pedestal</i> of the
+  <i>Microscope</i>, to cast, as it were, the magnifi'd appearance of the
+  Object upon the Ruler, and thereby exactly to measure the Diameter it
+  appears of through the Glass, which being compar'd with the Diameter it
+  appears of to the naked eye, will easily afford the quantity of its
+  magnifying.</p>
+
+<span class="sidenote">
+<a href="images/scheme-01.png" target="_blank"><i>Schem.</i> 1.</a><br /><i>Fig.</i> 3.
+</span>
+  <p>The <i>Microscope</i>, which for the most part I made use of, was
+  shap'd much like that in the sixth Figure of the first <i>Scheme</i>, the
+  Tube being for the most part not above six or seven inches long, though,
+  by reason it had four Drawers, it could very much be lengthened, as
+  occasion required; this was contriv'd with three Glasses; a small Object
+  Glass at A, a thinner Eye Glass about B, and a very deep one about C:
+  this I made use of only when I had occasion to see much of an Object at
+  once; the middle Glass conveying a very great company of radiating
+  Pencils, which would go another way, and throwing them upon the deep Eye
+  Glass. But when ever I had occasion to examine the small parts of a Body
+  more accurately, I took out the middle Glass, and only made use of one
+  Eye Glass with the Object Glass, for always the fewer the Refractions
+  are, the more bright and clear the Object appears. And therefore 'tis not
+  to be doubted, but could we make a<i> Microscope </i>to have one only
+  refraction, it would, <i>cæteris paribus</i>, far excel any other that
+  had a greater number. And hence it is, that if you take a very clear
+  piece of a broken <i>Venice</i> Glass, and in a Lamp draw it out into
+  very small hairs or threads, then holding the ends of these threads in
+  the flame, till they melt and run into a small round Globul, or drop,
+  which will hang at the end of the thread; and if further you stick
+  several of these upon the end of a stick with a little sealing Wax, so as
+  that the threads stand upwards, and then on a Whetstone first grind off a
+  good part of them, and afterward on a smooth Metal plate, with a little
+  Tripoly, rub them till they come to be very smooth; if one of these be
+  fixt with a little soft Wax against a small needle hole, prick'd through
+  a thin Plate of Brass, Lead, Pewter, or any other Metal, and an Object,
+  plac'd very near, be look'd at through it, it will both magnifie and make
+  some Objects more distinct then any of the great <i>Microscopes</i>. But
+  because these, though exceeding easily made, are yet very troublesome to
+  be us'd, because of their smallness, and the nearness of the Object;
+  therefore to prevent both these, and yet have only two Refractions, I
+<span class="sidenote">
+<a href="images/scheme-01.png" target="_blank"><i>Schem.</i> 1.</a><br /><i>Fig.</i> 4.
+</span>
+  provided me a Tube of Brass, shap'd much like that in the fourth Figure
+  of the first <i>Scheme</i>; into the smaller end of this I fixt with Wax
+  a good <i>plano convex</i> Object Glass, with the convex side towards the
+  Object, and into the bigger end I fixt also with wax a pretty large plano
+  <i>Convex</i> Glass, with the <i>convex</i> side towards my eye, then by
+  means of the small hole by the side, I fill'd the intermediate space
+  between these two Glasses with very clear Water, and with a Screw stopp'd
+  it in; then putting on a Cell for the Eye, I could perceive an Object
+  more bright then I could when the intermediate space was only fill'd with
+  Air, but this, for other inconveniences, I made but little use of.</p>
+
+<span class="sidenote">
+<a href="images/scheme-01.png" target="_blank"><i>Schem.</i> 1.</a><br /><i>Fig.</i> 3.
+</span>
+  <p>My way for fixing both the Glass and Object to the Pedestal most
+  conveniently was thus: Upon one side of a round Pedestal AB, in the sixth
+  Figure of the first <i>Scheme</i>, was fixt a small Pillar CC, on this
+  was fitted a small Iron Arm D, which could be mov'd up and down, and fixt
+  in any part of the Pillar, by means of a small Screw E; on the end of
+  this Arm was a small Ball fitted into a kind of socket F, made in the
+  side of the Brass Ring G, through which the small end of the Tube was
+  screw'd; by means of which contrivance I could place and fix the Tube in
+  what posture I desir'd (which for many Observations was exceeding
+  necessary) and adjusten it most exactly to any Object.</p>
+
+  <p>For placing the Object, I made this contrivance; upon the end of a
+  small brass Link or Staple HH, I so fastned a round Plate II, that it
+  might be turn'd round upon its Center K, and going pretty stiff, would
+  stand fixt in any posture it was set; on the side of this was fixt a
+  small Pillar P, about three quarters of an inch high, and through the top
+  of this was thrust a small Iron pin M, whose top just stood over the
+  Center of the Plate; on this top I fixt a small Object, and by means of
+  these contrivances I was able to turn it into all kind of positions, both
+  to my Eye and the Light; for by moving round the small Plate on its
+  center, could move it one way, and by turning the Pin M, I could move it
+  another way, and this without stirring the Glass at all, or at least but
+  very little; the Plate likewise I could move to and fro to any part of
+  the Pedestal (which in many cases was very convenient) and fix it also in
+  any Position, by means of a Nut N, which was screw'd on upon the lower
+  part of the Pillar CC. All the other Contrivances are obvious enough from
+  the draught, and will need no description.</p>
+
+</blockquote>
+
+  <p><i>Now though this were the Instrument I made most use of, yet I have
+  made several other Tryals with other kinds of Microscopes, which both for
+  </i>matter<i> and </i>form<i> were very different from common spherical
+  Glasses. I have made a </i>Microscope<i> with one piece of Glass, both
+  whose surfaces were </i>plains<i>. I have made another only with a
+  </i>plano concave<i>, without any kind of reflection, divers also by
+  means of </i>reflection<i>. I have made others of </i>Waters<i>,
+  </i>Gums<i>, </i>Resins<i>, </i>Salts<i>, </i>Arsenick<i>, </i>Oyls<i>,
+  and with divers other </i>mixtures of watery<i> and </i>oyly Liquors<i>.
+  And indeed the subject is capable of a great variety; but I find
+  generally none more useful then that which is made with </i>two
+  Glasses<i>, such as I have already describ'd.</i></p>
+
+  <p><i>What the things are I observ'd, the following descriptions will
+  manifest; in brief, they were either </i>exceeding small Bodies<i>, or
+  </i>exceeding small Pores<i>, or </i>exceeding small Motions<i>, some of
+  each of which the Reader will find in the following Notes, and such, as I
+  presume, (many of them at least) will be </i>new<i>, and perhaps not less
+  </i>strange<i>: Some </i>specimen<i> of each of which Heads the Reader
+  will find in the subsequent delineations, and indeed of some more then I
+  was willing there should be; which was occasioned by my first Intentions
+  to print a much greater number then I have since found time to compleat.
+  Of such therefore as I had, I selected only some few of every Head, which
+  for some particulars seem'd most observable, rejecting the rest as
+  superfluous to the present Design.</i></p>
+
+  <p><i>What each of the delineated Subjects are, the following
+  descriptions annext to each will inform, of which I shall here, only once
+  for all, add, That in divers of them the Gravers have pretty well
+  follow'd my directions and draughts; and that in making of them, I
+  indeavoured (as far as I was able) first to discover the true appearance,
+  and next to make a plain representation of it. This I mention the rather,
+  because of these kind of Objects there is much more difficulty to
+  discover the true shape, then of those visible to the naked eye, the same
+  Object seeming quite differing, in one position to the Light, from what
+  it really is, and may be discover'd in another. And therefore I never
+  began to make any draught before by many examinations in several lights,
+  and in several positions to those lights, I had discover'd the true form.
+  For it is exceeding difficult in some Objects, to distinguish between a
+  </i>prominency<i> and a </i>depression<i>, between a </i>shadow<i> and a
+  </i>black stain<i>, or a </i>reflection<i> and a </i>whiteness in the
+  colour<i>. Besides, the transparency of most Objects renders them yet
+  much more difficult then if they were </i>opacous<i>. The Eyes of a Fly
+  in one kind of light appear almost like a Lattice, drill'd through with
+  abundance of small holes; which probably may be the Reason, why the
+  Ingenious </i>Dr. Power<i> seems to suppose them such. In the Sunshine
+  they look like a Surface cover'd with golden Nails; in another posture,
+  like a Surface cover'd with Pyramids; in another with Cones; and in other
+  postures of quite other shapes; but that which exhibits the best, is the
+  Light collected on the Object, by those means I have already
+  describ'd.</i></p>
+
+  <p><i>And this was undertaken in prosecution of the Design which the
+  </i>ROYAL SOCIETY<i> has propos'd to it self. For the Members of the
+  Assembly having before their eys so many </i>fatal<i> Instances of the
+  errors and falshoods, in which the greatest part of mankind has so long
+  wandred, because they rely'd upon the strength of humane Reason alone,
+  have begun anew to correct all </i>Hypotheses<i> by sense, as Seamen do
+  their </i>dead Reckonings<i> by </i>C&#339;lestial Observations<i>; and
+  to this purpose it has been their principal indeavour to </i>enlarge
+  &amp; strengthen<i> the </i>Senses<i> by </i>Medicine<i>, and by such
+  </i>outward Instruments<i> as are proper for their particular works. By
+  this means they find some reason to suspect, that those effects of
+  Bodies, which have been commonly attributed to </i>Qualities<i>, and
+  those confess'd to be </i>occult<i>, are perform'd by the small
+  </i>Machines<i> of Nature, which are not to be discern'd without these
+  helps, seeming the meer products of </i>Motion<i>, </i>Figure<i>, and
+  </i>Magnitude<i>; and that the </i>Natural Textures<i>, which some call
+  the </i>Plastick faculty<i>, may be made in </i>Looms<i>, which a greater
+  perfection of Opticks may make discernable by these Glasses; so as now
+  they are no more puzzled about them, then the vulgar are to conceive, how
+  </i>Tapestry<i> or </i>flowred Stuffs<i> are woven. And the ends of all
+  these Inquiries they intend to be the </i>Pleasure<i> of Contemplative
+  minds, but above all, the </i>ease and dispatch<i> of the labours of mens
+  hands. They do indeed neglect no opportunity to bring all the </i>rare<i>
+  things of Remote Countries within the compass of their knowledge and
+  practice. But they still acknowledg their </i>most useful<i> Informations
+  to arise from </i>common<i> things, and from </i>diversifying<i> their
+  most </i>ordinary<i> operations upon them. They do not wholly reject
+  Experiments of meer </i>light<i> and </i>theory<i>; but they principally
+  aim at such, whose Applications will </i>improve and facilitate<i> the
+  present way of </i>Manual Arts<i>. And though some men, who are perhaps
+  taken up about less honourable Employments, are pleas'd to censure their
+  proceedings, yet they can shew more </i>fruits<i> of their first three
+  years, wherein they have assembled, then any other </i>Society<i> in
+  </i>Europe<i> can for a much larger space of time. 'Tis true, such
+  undertakings as theirs do commonly meet with small incouragement, because
+  men are generally rather taken with the </i>plausible<i> and
+  </i>discursive<i>, then the </i>real<i> and the solid part of Philosophy;
+  yet by the good fortune of their institution, in an Age of all others the
+  most </i>inquisitive<i>, they have been assisted by the
+  </i>contribution<i> and </i>presence<i> of very many of the chief
+  </i>Nobility<i> and </i>Gentry<i>, and others who are some of the
+  </i>most considerable<i> in their several Professions. But that that yet
+  farther convinces me of the </i>Real esteem<i> that the more
+  </i>serious<i> part of men have of this </i>Society<i>, is, that several
+  </i>Merchants<i>, men who act in earnest (whose Object is </i>meum &amp;
+  tuum<i>, that great </i>Rudder<i> of humane affairs) have adventur'd
+  considerable sums of </i>Money<i>, to put in practice what some of our
+  Members have contrived, and have continued </i>stedfast<i> in their good
+  opinions of such Indeavours, when not one of a hundred of the vulgar have
+  believed their undertakings feasable. And it it also fit to be added,
+  that they have one advantage peculiar to themselves, that very many of
+  their number are </i>men of Converse and Traffick<i>; which is a good
+  Omen, that their attempts will bring Philosophy from </i>words<i> to
+  </i>action<i>, seeing the men of Business have had so great a share in
+  their first foundation.</i></p>
+
+  <p><i>And of this kind I ought not to conceal one particular
+  </i>Generosity<i>, which more nearly concerns my self. It is the
+  </i>munificence<i> of </i>Sir John Cutler<i>, in endowing a Lecture for
+  the promotion of </i>Mechanick Arts<i>, to be governed and directed by
+  This </i>Society.<i>This </i>Bounty<i> I mention for the
+  </i>Honourableness<i> of the thing it self, and for the expectation which
+  I have of the </i>efficacy<i> of the </i>Example<i>; for it cannot now be
+  objected to them, that their Designs will be esteemed </i>frivolous<i>
+  and </i>vain<i>, when they have such a </i>real Testimony<i> of the
+  </i>Approbation<i> of a </i>Man<i> that is such an </i>eminent
+  Ornament<i> of this renowned City, and one, who, by the </i>Variety<i>,
+  and the </i>happy Success<i>, of his negotiations, has given evident
+  proofs, that he is not easie to be deceiv'd. This Gentleman has well
+  observ'd, that the </i>Arts<i> of life have been too long
+  </i>imprison'd<i> in the dark shops of Mechanicks themselves, &amp; there
+  </i>hindred from growth<i>, either by ignorance, or self-interest: and he
+  has bravely </i>freed<i> them from these </i>inconveniences<i>: He hath
+  not only obliged </i>Tradesmen<i>, but </i>Trade<i> it self: He has done
+  a work that is worthy of </i>London<i>, and has taught the chief City of
+  Commerce in the world the right way how Commerce is to be improv'd. We
+  have already seen many other great signs of Liberality and a large mind,
+  from the same hand: For by his </i>diligence<i> about the </i>Corporation
+  for the Poor<i>; by his honorable </i>Subscriptions<i> for the rebuilding
+  of St. Paul's; by his chearful </i>Disbursment<i> for the replanting of
+  </i>Ireland<i>, and by many other such </i>publick works<i>, he has shewn
+  by what means he indeavours to </i>establish<i> his Memory; and now by
+  this last gift he has done that, which became one of the </i>wisest
+  Citizens<i> of our Nation to accomplish, seeing one of the </i>wisest of
+  our Statesmen, the Lord Verulam<i>, first propounded it.</i></p>
+
+  <p><i>But to return to my Subject, from a digression, which, I hope, my
+  Reader will pardon me, seeing the Example is so rare that I can make no
+  more such digressions. If these my first Labours shall be any wayes
+  useful to inquiring men, I must attribute the incouragement and promotion
+  of them to a very </i>Reverend<i> and </i>Learned Person<i>, of whom this
+  ought in justice to be said, </i>That there is scarce any one Invention,
+  which this Nation has produc'd in our Age, but it has some way or other
+  been set forward by his assistance<i>. My Reader, I believe, will quickly
+  ghess, that it is </i>Dr. Wilkins<i> that I mean. He is indeed a man born
+  for the </i>good<i> of </i>mankind<i>, and for the </i>honour<i> of his
+  </i>Country<i>. In the </i>sweetness<i> of whose </i>behaviour<i>, in the
+  </i>calmness<i> of his </i>mind<i>, in the </i>unbounded goodness<i> of
+  his </i>heart<i>, we have an evident Instance, what the true and the
+  </i>primitive unpassionate Religion<i> was, before it was </i>sowred<i>
+  by particular </i>Factions.<i> In a word, his </i>Zeal<i> has been so
+  </i>constant<i> and </i>effectual<i> in advancing all good and profitable
+  </i>Arts, that<i> as one of the Antient </i>Romans<i> said of
+  </i>Scipio<i>, </i>That he thanked God that he was a <i>Roman</i>;
+  because whereever <i>Scipio</i> had been born, there had been the seat of
+  the Empire of the world<i>: So may I thank God, that </i>Dr. Wilkins<i>
+  was an </i>Englishman<i>, for whereever he had lived, there had been the
+  chief Seat of </i>generous Knowledge<i> and </i>true Philosophy<i>. To
+  the truth of this, there are so many worthy men living that will
+  subscribe, that I am confident, what I have here said, will not be looked
+  upon, by any ingenious Reader, as a </i>Panegyrick<i>, but only as a
+  </i>real testimony<i>.</i></p>
+
+  <p><i>By the Advice of this </i>Excellent man<i> I first set upon this
+  Enterprise, yet still came to it with much </i>Reluctancy<i>, because I
+  was to follow the footsteps of so eminent a Person as </i>Dr. Wren<i>,
+  who was the first that attempted any thing of this nature; whose original
+  draughts do now make one of the Ornaments of that great Collection of
+  Rarities in the </i>Kings Closet<i>. This </i>Honor<i>, which his first
+  beginnings of this kind have receiv'd, to be admitted into the most
+  famous place of the world, did not so much </i>incourage<i>, as the
+  </i>hazard<i> of coming after </i>Dr. Wren<i> did </i>affright<i> me; for
+  of him I must, affirm, that, since the time of </i>Archimedes<i>, there
+  scarce ever met in one man, in so great a perfection, such a
+  </i>Mechanical Hand<i>, and so </i>Philosophical<i> a
+  </i>Mind<i>.</i></p>
+
+  <p><i>But at last, being assured both by </i>Dr. Wilkins<i>, and </i>Dr.
+  Wren<i> himself, that he had given over his intentions of prosecuting it,
+  and not finding that there was any else design'd the pursuing of it, I
+  set upon this undertaking, and was not a little incourag'd to proceed in
+  it, by the Honour the </i>Royal Society<i> was pleas'd to favour me with,
+  in approving of those draughts (which from time to time as I had an
+  opportunity of describing) I presented to them. And particularly by the
+  Incitements of divers of those Noble and excellent Persons of it, which
+  were my more especial Friends, who were not less urgent with me for the
+  publishing, then for the prosecution of them.</i></p>
+
+  <p><i>After I had almost compleated these Pictures and Observations
+  (having had divers of them ingraven, and was ready to send them to the
+  Press) I was inform'd, that the Ingenious Physitian </i>Dr. Henry
+  Power<i> had made several </i>Microscopical<i> Observations, which had I
+  not afterwards, upon our interchangably viewing each others Papers, found
+  that they were for the most part differing from mine, either in the
+  Subject it self, or in the particulars taken notice of; and that his
+  design was only to print Observations without Pictures, I had even then
+  </i>suppressed<i> what I had so far proceeded in. But being further
+  </i>excited<i> by several of my Friends, in complyance with their
+  opinions, that it would not be unacceptable to several inquisitive Men,
+  and hoping also, that I should thereby discover something New to the
+  World, I have at length cast in my Mite, into the vast Treasury of </i>A
+  Philosophical History<i>. And it is my </i>hope<i>, as well as
+  </i>belief<i>, that these my </i>Labours<i> will be no more comparable to
+  the </i>Productions<i> of many other </i>Natural Philosophers<i>, who are
+  now every where busie about </i>greater<i> things; then my </i>little
+  Objects<i> are to be compar'd to the greater and more beautiful </i>Works
+  of Nature<i>, A Flea, a Mite, a Gnat, to an Horse, an Elephant, or a
+  Lyon.</i></p>
+
+  <div class="figcenter" style="width:60%;">
+      <a href="images/rule-05.png"><img width="100%" src="images/rule-05.png"
+      alt="Decorative rule" /></a>
+  </div>
+  <br clear="all" />
+
+<h2>MICROGRAPHIA,</h2>
+
+<p class="center">OR SOME</p>
+
+<h3>Physiological Descriptions</h3>
+
+<p class="center">OF</p>
+
+<h2>MINUTE BODIES,</h2>
+
+<p class="center">MADE BY</p>
+
+<h3>MAGNIFYING GLASSES;</h3>
+
+<p class="center">WITH</p>
+
+<h3>OBSERVATIONS and INQUIRIES thereupon.</h3>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsI" id="obsI">I</a>. <i>Of the Point of a sharp small Needle.</i></h3>
+
+  <p>
+  <span title="Word with illuminated initial: As">
+  <img align="left" src="images/illumined-A2.png" alt="Illuminated A in As" />s
+  </span>
+  in <i>Geometry</i>, the most natural way of beginning is from a
+  Mathematical <i>point</i>; so is the same method in Observations and
+  <i>Natural history</i> the most genuine, simple, and instructive. We must
+  first endevour to make <i>letters</i>, and draw <i>single</i> strokes
+  true, before we venture to write whole <i>Sentences</i>, or to draw large
+  <i>Pictures</i>. And in <i>Physical</i> Enquiries, we must endevour to
+  follow Nature in the more <i>plain</i> and <i>easie</i> ways she treads
+  in the most <i>simple</i> and <i>uncompounded bodies</i>, to trace her
+  steps, and be acquainted with her manner of walking there, before we
+  venture our selves into the multitude of <i>meanders</i> she has in
+  <i>bodies of a more complicated</i> nature; lest, being unable to
+  distinguish and judge of our way, we quickly lose both <i>Nature</i> our
+  Guide, and <i>our selves</i> too, and are left to wander in the
+  <i>labyrinth</i> of groundless opinions; wanting both <i>judgment</i>,
+  that <i>light</i>, and <i>experience</i>, that <i>clew</i>, which should
+  direct our proceedings.</p>
+
+  <p>We will begin these our Inquiries therefore with the Observations of
+  Bodies of the most <i>simple nature</i> first, and so gradually proceed
+  to those of a more <i>compounded</i> one. In prosecution of which method,
+  we shall begin with a <i>Physical point</i>; of which kind the <i>Point
+  of a Needle</i> is commonly reckon'd for one; and is indeed, for the most
+  part, made so sharp, that the naked eye cannot distinguish any parts of
+  it: It very easily pierces, and makes its way through all kind of bodies
+  softer then it self: But if view'd with a very good <i>Microscope</i>, we
+  may find that the <i>top</i> of a Needle (though as to the sense
+  very <i>sharp</i>) appears a <i>broad</i>, <i>blunt,</i> and very
+  <i>irregular</i> end; not resembling a Cone, as is imagin'd, but onely a
+  piece of a tapering body, with a great part of the top remov'd, or
+  deficient. The Points of Pins are yet more blunt, and the Points of the
+  most curious Mathematical Instruments do very seldome arrive at so great
+  a sharpness; how much therefore can be built upon demonstrations made
+  onely by the productions of the Ruler and Compasses, he will be better
+  able to consider that shall but view those <i>points</i> and <i>lines</i>
+  with a <i>Microscope</i>.</p>
+
+  <p>Now though this point be commonly accounted the sharpest (whence when
+  we would express the sharpness of a point the most <i>superlatively</i>,
+  we say, As sharp as a Needle) yet the <i>Microscope</i> can afford us
+  hundreds of Instances of Points many thousand times sharper: such as
+  those of the <i>hairs</i>, and <i>bristles</i>, and <i>claws</i> of
+  multitudes of <i>Insects</i>; the <i>thorns</i>, or <i>crooks</i>, or
+  <i>hairs</i> of <i>leaves</i>, and other small vegetables; nay, the ends
+  of the <i>stiriæ</i> or small <i>parallelipipeds</i> of <i>Amianthus</i>,
+  and <i>alumen plumosum</i>; of many of which, though the Points are so
+  sharp as not to be visible, though view'd with a <i>Microscope</i> (which
+  magnifies the Object, in bulk, above a million of times) yet I doubt not,
+  but were we able <i>practically</i> to make <i>Microscopes</i> according
+  to the <i>theory</i> of them, we might find hills, and dales, and pores,
+  and a sufficient bredth, or expansion, to give all those parts
+  elbow-room, even in the blunt top of the very Point of any of these so
+  very sharp bodies. For certainly the <i>quantity</i> or extension of any
+  body may be <i>Divisible in infinitum</i>, though perhaps not the
+  <i>matter</i>.</p>
+
+<span class="sidenote">
+<a href="images/scheme-02.png" target="_blank"><i>Schem.</i> 2.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>But to proceed: The Image we have here exhibited in the first Figure, was the top of a
+  small and very sharp Needle, whose point <i>aa</i> nevertheless appear'd
+  through the <i>Microscope</i> above a quarter of an inch broad, not round
+  nor flat, but <i>irregular</i> and <i>uneven</i>; so that it seem'd to
+  have been big enough to have afforded a hundred armed Mites room enough
+  to be rang'd by each other without endangering the breaking one anothers
+  necks, by being thrust off on either side. The surface of which, though
+  appearing to the naked eye very smooth, could not nevertheless hide a
+  multitude of holes and scratches and ruggednesses from being discover'd
+  by the <i>Microscope</i> to invest it, several of which inequalities (as
+  A, B, C, seem'd <i>holes</i> made by some small specks of <i>Rust</i>;
+  and D some <i>adventitious body</i>, that stuck very close to it) were
+  <i>casual</i>. All the rest that roughen the surface, were onely so many
+  marks of the rudeness and bungling of <i>Art</i>. So unaccurate is it, in
+  all its productions, even in those which seem most neat, that if examin'd
+  with an organ more acute then that by which they were made, the more we
+  see of their <i>shape</i>, the less appearance will there be of their
+  <i>beauty</i>: whereas in the works of <i>Nature</i>, the deepest
+  Discoveries shew us the greatest Excellencies. An evident Argument, that
+  he that was the Author of all these things, was no other then
+  <i>Omnipotent</i>; being able to include as great a variety of parts and
+  contrivances in the yet smallest Discernable Point, as in those vaster
+  bodies (which comparatively are called also Points) such as the
+  <i>Earth</i>, <i>Sun</i>, or <i>Planets</i>. Nor need it seem strange
+  that the Earth it self may be by <i>Analogie</i> call'd a Physical Point:
+  For as its body, though now so near us as to fill our eys and
+  fancies with a sense of the vastness of it, may by a little Distance, and
+  some convenient <i>Diminishing</i> Glasses, be made vanish into a scarce
+  visible Speck, or Point (as I have often try'd on the <i>Moon</i>, and
+  (when not too bright) on the <i>Sun</i> it self.) So, could a Mechanical
+  contrivance succesfully answer our <i>Theory</i>, we might see the least
+  spot as big as the Earth it self; and Discover, as <i>Des Cartes</i>
+  also conjectures (<i>Diop.</i> ch. 10. § 9.),
+  as great a variety of bodies in the <i>Moon</i>, or <i>Planets</i>, as in
+  the <i>Earth</i>.</p>
+
+  <p>But leaving these Discoveries to future Industries, we shall proceed
+  to add one Observation more of a <i>point</i> commonly so call'd, that
+  is, the mark of a <i>full stop</i>, or <i>period</i>. And for this
+  purpose I observed many both <i>printed</i> ones and <i>written</i>; and
+  among multitudes I found <i>few</i> of them more <i>round</i> or
+<span class="sidenote">
+<a href="images/scheme-02.png" target="_blank"><i>Schem.</i> 2.</a><br /><i>Fig.</i> 3.
+</span>
+  <i>regular</i> then this which I have delineated in the third figure of
+  the second Scheme, but <i>very many</i> abundantly <i>more
+  disfigur'd</i>; and for the most part if they seem'd equally round to the
+  eye, I found those points that had been made by a <i>Copper-plate,</i>
+  and Roll-press, to be as misshapen as those which had been made with
+  <i>Types</i>, the most curious and smothly <i>engraven strokes</i> and
+  <i>points</i>, looking but as so many <i>furrows</i> and <i>holes</i>,
+  and their <i>printed impressions</i>, but like <i>smutty daubings</i> on
+  a matt or uneven floor with a blunt extinguisht brand or stick's end. And
+  as for <i>points</i> made with a <i>pen</i> they were much <i>more
+  ragged</i> and <i>deformed</i>. Nay, having view'd certain pieces of
+  exceeding curious writing of the kind (one of which in the bredth of a
+  <i>two-pence</i> compris'd <i>the Lords prayer, the Apostles Creed, the
+  ten Commandments, and about half a dozen verses besides of the Bible</i>,
+  whose <i>lines</i> were <i>so small</i> and <i>near together</i>, that I
+  was unable to <i>number</i> them with my <i>naked eye</i>,) a very
+  ordinary <i>Microscope</i>, I had then about me, inabled me to see that
+  what the Writer of it had asserted was <i>true</i>, but withall
+  discover'd of what pitifull <i>bungling scribbles</i> and <i>scrawls</i>
+  it was compos'd, <i>Arabian</i> and <i>China characters</i> being almost
+  as well shap'd, yet thus much I must say for the Man, that it was for the
+  most part <i>legible</i> enough, though in some places there wanted a
+  good <i>fantsy</i> well <i>preposest</i> to help one through. If this
+  manner <i>of small writing</i> were made <i>easie</i> and
+  <i>practicable</i> (and I think I know such a one, but have never yet
+  made tryal of it, whereby one might be inabled to write <i>a great
+  deale</i> with <i>much ease</i>, and <i>accurately</i> enough in a very
+  <i>little roome</i>) it might be of very good use to convey <i>secret
+  Intelligence</i> without any danger of <i>Discovery</i> or
+  <i>mistrusting</i>. But to come again to the point. The
+  <i>Irregularities</i> of it are caused by three or four
+  <i>coadjutors</i>, one of which is, the <i>uneven surface</i> of the
+  <i>paper</i>, which at best appears no smother then a very course piece
+  of <i>shag'd cloth</i>, next the <i>irregularity of the Type</i> or
+  <i>Ingraving</i>, and a third is the <i>rough Daubing</i> of the
+  <i>Printing-Ink</i> that lies upon the instrument that makes the
+  impression, to all which, add the <i>variation</i> made by the Different
+  <i>lights</i> and <i>shadows</i>, and you may have sufficient reason to
+  guess that a <i>point</i> may appear much more <i>ugly</i> then
+  <i>this</i>, which I have here presented, which though it appear'd
+  through the <i>Microscope</i> <i>gray</i>, like a great splatch of
+  <i>London</i> dirt, about three inches over; yet to the <i>naked eye</i>
+  it was <i>black</i> and no bigger then that in the midst of the Circle A.
+  And could I have found Room in this Plate to have inserted an O
+  you should have seen that the <i>letters</i> were not more distinct then
+  the <i>points</i> of Distinction, nor a <i>drawn circle</i> more exactly
+  <i>so</i>, then we have now shown a <i>point</i> to be a
+  <i>point</i>.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsII" id="obsII">II</a>. <i>Of the Edge of a Razor.</i></h3>
+
+  <p>The sharpest <i>Edge</i> hath the same kind of affinity to the
+  sharpest <i>Point</i> in Physicks, as a <i>line</i> hath to a
+  <i>point</i> in Mathematicks; and therefore the Treaty concerning this,
+  may very properly be annexed to the former. A Razor doth appear to be a
+  Body of a very neat and curious aspect, till more closely viewed by the
+  <i>Microscope</i>, and there we may observe its very Edge to be of all
+  kind of shapes, except what it should be. For examining that of a very
+  sharp one, I could not find that any part of it had any thing of
+  sharpness in it; but it appeared a rough surface of a very considerable
+  bredth from side to side, the narrowest part not seeming thinner then the
+  back of a pretty thick Knife. Nor is't likely that it should appear any
+  otherwise, since as we just now shew'd that a <i>point</i> appear'd a
+  <i>circle</i>, 'tis rational a <i>line</i> should be a
+  <i>parallelogram</i>.</p>
+
+<span class="sidenote">
+<a href="images/scheme-02.png" target="_blank"><i>Schem.</i> 2.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>Now for the drawing this second Figure
+  (which represents a part of the Edge
+  about half a quarter of an inch long of a Razor well set) I so plac'd it
+  between the Object-glass &amp; the light, that there appear'd a
+  reflection from the very Edge, represented by the white line
+  <i>abcdef</i>. In which you may perceive it to be somewhat sharper then
+  elsewhere about <i>d</i>, to be indented or pitted about <i>b</i>, to be
+  broader and thicker about <i>c</i>, and unequal and rugged about
+  <i>e</i>, and pretty even between <i>ab</i> and <i>ef</i>. Nor was that
+  part of the Edge <i>ghik</i> so smooth as one would imagine so smooth
+  bodies as a Hone and Oyl should leave it; for besides those multitudes of
+  scratches, which appear to have raz'd the surface <i>ghik</i>, and to
+  cross each other every way which are not half of them exprest in the
+  Figure, there were several great and deep scratches, or furrows, such as
+  <i>gh</i> and <i>ik</i>, which made the surface yet more rugged, caus'd
+  perhaps by some small Dust casually falling on the Hone, or some harder
+  or more flinty part of the Hone it self. The other part of the Razor
+  <i>ll</i>, which is polish'd on a grinding-stone, appear'd much rougher
+  then the other, looking almost like a plow'd field, with many parallels,
+  ridges, and furrows, and a cloddy, as 'twere, or an uneven surface: nor
+  shall we wonder at the roughnesses of those surfaces, since even in the
+  most curious wrought Glasses for <i>Microscopes</i>, and other Optical
+  uses, I have, when the Sun has shone well on them, discover'd their
+  surface to be variously raz'd or scratched, and to consist of an infinite
+  of small broken surfaces, which reflect the light of very various and
+  differing colours. And indeed it seems impossible by Art to cut the
+  surface of any hard and brittle body smooth, since <i>Putte</i>, or even
+  the most curious <i>Powder</i> that can be made use of, to polish such a
+  body, must consist of little hard rough particles, and each of them must
+  cut its way, and consequently leave some kind of gutter or furrow
+  behind it. And though Nature does seem to do it very readily in all kinds
+  of fluid bodies, yet perhaps future observators may discover even these
+  also rugged; it being very probable, as I elsewhere shew, that fluid
+  bodies are made up of small solid particles variously and strongly mov'd,
+  and may find reason to think there is scarce a surface <i>in rerum
+  naturâ</i> perfectly smooth. The black spot <i>mn</i>, I ghess to be some
+  small speck of rust, for that I have oft observ'd to be the manner of the
+  working of Corrosive Juyces. To conclude, this Edge and piece of a Razor,
+  if it had been really such as it appear'd through the <i>Microscope</i>,
+  would scarcely have serv'd to cleave wood, much less to have cut off the
+  hair of beards, unless it were after the manner that <i>Lucian</i>
+  merrily relates <i>Charon</i> to have made use of, when with a Carpenters
+  Axe he chop'd off the beard of a sage Philosopher, whose gravity he very
+  cautiously fear'd would indanger the oversetting of his Wherry.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsIII" id="obsIII">III</a>. <i>Of fine Lawn, or Linnen Cloth.</i></h3>
+
+  <p>This is another product of Art, A piece of the finest Lawn I was able
+  to get, so curious that the threads were scarce discernable by the naked
+  eye, and yet through an ordinary <i>Microscope</i> you may perceive what a goodly
+  piece of <i>coarse Matting</i> it is; what proportionable cords each of
+  its threads are, being not unlike, both in shape and size, the bigger and
+  coarser kind of <i>single Rope-yarn</i>, wherewith they usually make
+  <i>Cables</i>. That which makes the Lawn so transparent, is by the
+  <i>Microscope</i>, nay by the naked eye, if attentively viewed, plainly
+  enough evidenced to be the multitude of square holes which are left
+  between the threads, appearing to have much more hole in respect of the
+  intercurrent parts then is for the most part left in a
+  <i>lattice-window</i>, which it does a little resemble, onely the
+  crossing parts are round and not flat.</p>
+
+  <p>These threads that compose this fine contexture, though they are as
+  small as those that constitute the finer sorts of Silks, have
+  notwithstanding nothing of their glossie, pleasant, and lively
+  reflection. Nay, I have been informed both by the Inventor himself, and
+  several other eye-witnesses, that though the flax, out of which it is
+  made, has been (by a singular art, of that excellent Person, and Noble
+  Vertuoso, M. <i>Charls Howard</i>, brother to the <i>Duke of Norfolk</i>)
+  so curiously dress'd and prepar'd, as to appear both to the eye and the
+  touch, full as <i>fine</i> and as <i>glossie</i>, and to receive all
+  kinds of colours, as well as Sleave-Silk; yet when this Silken Flax is
+  twisted into threads, it quite loseth its former luster, and becomes as
+  plain and base a thread to look on, as one of the same bigness, made of
+  common Flax.</p>
+
+  <p>The reason of which odd <i>Phenomenon</i> seems no other then this;
+  that though the curiously drest Flax has its parts so exceedingly small,
+  as to equallize, if not to be much smaller then the clew of the
+  Silk-worm, especially in thinness, yet the differences between the
+  figures of the constituting filaments are so great, and their substances
+  so various, that whereas those of the <i>Silk</i> are
+  <i>small</i>, <i>round</i>, <i>hard</i>, <i>transparent,</i> and to their
+  bigness proportionably <i>stiff</i>, so as each filament preserves its
+  proper <i>Figure</i>, and consequently its vivid <i>reflection</i>
+  intire, though twisted into a thread, if not too hard; those of Flax are
+  <i>flat</i>, <i>limber</i>, <i>softer,</i> and <i>less transparent</i>,
+  and in twisting into a thread they joyn, and lie so close together, as to
+  lose their own, and destroy each others particular reflections. There
+  seems therefore three Particulars very requisite to make the so drest
+  Flax appear Silk also when spun into threads. First, that the substance
+  of it should be made more <i>clear</i> and <i>transparent</i>, Flax
+  retaining in it a kind of opacating brown, or yellow; and the parts of
+  the whitest kind I have yet observ'd with the <i>Microscope</i> appearing
+  white, like flaw'd Horn or Glass, rather then clear, like clear Horn or
+  Glass. Next that, the filaments should each of them be <i>rounded</i>, if
+  that could be done, which yet is not so very necessary, if the first be
+  perform'd, and this third, which is, that each of the small filaments be
+  <i>stifned</i>; for though they be square, or flat, provided they be
+  <i>transparent</i> and stiff, much the same appearances must necessarily
+  follow. Now, though I have not yet made trial, yet I doubt not, but that
+  both these proprieties may be also induc'd upon the Flax, and perhaps too
+  by one and the same Expedient, which some trials may quickly inform any
+  ingenious attempter of, who from the use and profit of such an Invention,
+  may find sufficient argument to be prompted to such Inquiries. As for the
+  <i>tenacity</i> of the substance of Flax, out of which the thread is
+  made, it seems much inferiour to that of Silk, the one being a
+  <i>vegetable</i>, the other an <i>animal</i> substance. And whether it
+  proceed from the better concoction, or the more homogeneous constitution
+  of <i>animal</i> substances above those of <i>vegetables</i>, I do not
+  here determine; yet since I generally find, that <i>vegetable</i>
+  substances do not equalize the <i>tenacity</i> of <i>animal</i>, nor
+  these the <i>tenacity</i> of some purified <i>mineral</i> substances; I
+  am very apt to think, that the <i>tenacity</i> of bodies does not proceed
+  from the <i>hamous</i>, or <i>hooked</i> particles, as the
+  <i>Epicureans</i> and some modern <i>Philosophers</i> have imagin'd; but
+  from the more exact <i>congruity</i> of the constituent parts, which are
+  contiguous to each other, and so bulky, as not to be easily separated, or
+  shatter'd, by any small pulls or concussion of heat.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsIV" id="obsIV">IV</a>. <i>Of fine waled Silk, or Taffety.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-03.png" target="_blank"><i>Schem.</i> 3.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>This is the
+  appearance of a piece of very fine Taffety-riband in the bigger
+  magnifying Glass, which you see exhibits it like a very convenient
+  substance to make Bed-matts, or Door-matts of, or to serve for Beehives,
+  Corn-scuttles, Chairs, or Corn-tubs, it being not unlike that kind of
+  work, wherewith in many parts in <i>England</i>, they make such Utensils
+  of Straw, a little wreathed, and bound together with thongs of Brambles.
+  For in this Contexture, each little filament, fiber, or clew of the
+  Silk-worm, seem'd about the bigness of an ordinary Straw, as appears by
+  the little irregular pieces, <i>ab</i>, <i>cd</i>, and <i>ef</i>;
+  The <i>Warp</i>, or the thread that ran crossing the Riband, appear'd
+  like a single Rope of an Inch Diameter; but the <i>Woof</i>, or the
+  thread that ran the length of the Riband, appear'd not half so big. Each
+  Inch of six-peny-broad Riband appearing no less then a piece of Matting
+  Inch and half thick, and twelve foot square, a few yards of this, would
+  be enough to floor the long Gallery of the <i>Loure</i> at <i>Paris</i>.
+  But to return to our piece of Riband: It affords us a not unpleasant
+  object, appearing like a bundle, or wreath, of very clear and transparent
+  <i>Cylinders</i>, if the Silk be white, and curiously ting'd; if it be
+  colour'd, each of those small horney <i>Cylinders</i> affording in some
+  place or other of them, as vivid a reflection, as if it had been sent
+  from a <i>Cylinder</i> of Glass or Horn. In-so-much, that the reflexions
+  of Red, appear'd as if coming from so many <i>Granates</i>, or
+  <i>Rubies</i>. The loveliness of the colours of Silks above those of
+  hairy Stuffs, or Linnen, consisting, as I else-where intimate, chiefly in
+  the transparency, and vivid reflections from the <i>Concave</i>, or inner
+  surface of the <i>transparent Cylinder</i>, as are also the colours of
+  Precious Stones; for most of the reflections from each of these
+  <i>Cylinders</i>, come from the <i>Concave</i> surface of the air, which
+  is as 'twere the foil that incompasses the <i>Cylinder</i>. The colours
+  with which each of these <i>Cylinders</i> are ting'd, seem partly to be
+  superficial, and sticking to the out-sides of them; and partly, to be
+  imbib'd, or sunck into the substance of them: for Silk, seeming to be
+  little else then a dried thread of Glew, may be suppos'd to be very
+  easily relaxt, and softened, by being steeped in warm, nay in cold, if
+  penetrant, juyces or liquors. And thereby those tinctures, though they
+  tinge perhaps but a small part of the substance, yet being so highly
+  impregnated with the colour, as to be almost black with it, may leave an
+  impression strong enough to exhibite the desir'd colour. A pretty kinde
+  of artificial Stuff I have seen, looking almost like transparent
+  Parchment, Horn, or Ising-glass, and perhaps some such thing it may be
+  made of, which being transparent, and of a glutinous nature, and easily
+  mollified by keeping in water, as I found upon trial, had imbib'd, and
+  did remain ting'd with a great variety of very vivid colours, and to the
+  naked eye, it look'd very like the substance of the Silk. And I have
+  often thought, that probably there might be a way found out, to make an
+  artificial glutinous composition, much resembling, if not full as good,
+  nay better, then that Excrement, or whatever other substance it be out of
+  which, the Silk-worm wire-draws his clew. If such a composition were
+  found, it were certainly an easie matter to find very quick ways of
+  drawing it out into small wires for use. I need not mention the use of
+  such an Invention, nor the benefit that is likely to accrue to the
+  finder, they being sufficiently obvious. This hint therefore, may, I
+  hope, give some Ingenious inquisitive Person an occasion of making some
+  trials, which if successfull, I have my aim, and I suppose he will have
+  no occasion to be displeas'd.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsV" id="obsV">V</a>. <i>Of watered Silks, or Stuffs.</i></h3>
+
+  <p>There are but few <i>Artificial</i> things that are worth observing
+  with a <i>Microscope</i>, and therefore I shall speak but briefly
+  concerning them. For the Productions of art are such rude mis-shapen
+  things, that when view'd with a <i>Microscope</i>, is little else
+  observable, but their deformity. The most curious Carvings appearing no
+  better then those rude <i>Russian</i> Images we find mention'd in
+  <i>Purchas</i>, where three notches at the end of a Stick, stood for a
+  face. And the most smooth and burnish'd surfaces appear most rough and
+  unpolisht: So that my first Reason why I shall add but a few observations
+  of them, is, their mis-shapen form; and the next, is their uselessness.
+  For why should we trouble our selves in the examination of that form or
+  shape (which is all we are able to reach with a <i>Microscope</i>) which
+  we know was design'd for no higher a use, then what we were able to view
+  with our naked eye? Why should we endeavour to discover mysteries in that
+  which has no such thing in it? And like <i>Rabbins</i> find out
+  <i>Caballisms</i>, and <i>ænigmâs</i> in the Figure, and placing of
+  Letters, where no such thing lies hid: whereas in <i>natural</i> forms
+  there are some so small, and so curious, and their design'd business so
+  far remov'd beyond the reach of our sight, that the more we magnify the
+  object, the more excellencies and mysteries do appear; And the more we
+  discover the imperfections of our senses; and the Omnipotency and
+  Infinite perfections of the great Creatour. I shall therefore onely add
+  one or two Observations more <i>artificial</i> things, and then come to
+  the Treaty concerning such matters as are the Productions of a more
+  curious Workman. One of these, shall be that of a piece of water'd Silk,
+<span class="sidenote">
+<a href="images/scheme-03.png" target="_blank"><i>Schem.</i> 3.</a><br /><i>Fig.</i> 2.
+</span>
+  represented in the second Figure of the third <i>Scheme</i>,
+  as it appear'd through the
+  least magnifying Glass. <i>AB</i> signifying the long way of the Stuff,
+  and <i>CD</i> the broad way. This Stuff, if the right side of it be
+  looked upon, appears to the naked eye, all over so waved, undulated, or
+  grain'd, with a curious, though irregular variety of brighter and darker
+  parts, that it adds no small gracefulness to the Gloss of it. It is so
+  known a propriety, that it needs but little explication, but it is
+  observable, which perhaps everyone has not considered, that those parts
+  which appear the darker part of the wave, in one position to the light,
+  in another appears the lighter, and the contrary; and by this means the
+  undulations become transient, and in a continual change, according as the
+  position of the parts in respect of the incident beams of light is
+  varied. The reason of which odd <i>phænomena</i>, to one that has but
+  diligently examin'd it even with his naked eye, will be obvious enough.
+  But he that observes it with a <i>Microscope</i>, may more easily
+  perceive what this <i>Proteus</i> is, and how it comes to change its
+  shape. He may very easily perceive, that it proceeds onely from the
+  variety of the <i>Reflections</i> of light, which is caus'd by the
+  various <i>shape of the Particles</i>, or little protuberant parts of the
+  thread that compose the surface; and that those parts of the waves that
+  appear the brighter, throw towards the eye a
+  multitude of small reflections of light, whereas the darker scarce afford
+  any. The reason of which reflection, the <i>Microscope</i> plainly
+  discovers, as appears by the Figure. In which you may perceive, that the
+  brighter parts of the surface consist of an abundance of large and strong
+  reflections, denoted by <i>a</i>, <i>a</i>, <i>a</i>, <i>a</i>, <i>a</i>,
+  &amp;c. for the surfaces of those threads that run the <i>long way</i>,
+  are by the Mechanical process of watering, <i>creas'd</i> or
+  <i>angled</i> in another kind of posture then they were by the weaving:
+  for by the weaving they are onely <i>bent round</i> the warping threads;
+  but by the watering, they are <i>bent with an angle, or elbow</i>, that
+  is in stead of lying, or being bent <i>round</i> the threads, as in the
+  third Figure, <i>a</i>, <i>a</i>, <i>a</i>, <i>a</i>, <i>a</i>, are about
+  <i>b</i>, <i>b</i>, <i>b</i> (<i>b</i>, <i>b</i>, <i>b</i> representing
+  the ends, as 'twere, of the cross threads, they are bent about) they are
+  creas'd on the top of those threads, with an <i>angle</i>, as in the
+  fourth Figure, and that with all imaginable variety; so that, whereas
+  before they reflected the light onely from one point of the round
+  surface, as about <i>c</i>, <i>c</i>, <i>c</i>, they now when water'd,
+  reflect the beams from more then half the whole surface, as <i>de</i>,
+  <i>de</i>, <i>de</i>, and in other postures they return no reflections at
+  all from those surfaces. Hence in one posture they compose the brighter
+  parts of the waves, in another the darker. And these reflections are also
+  varied, according as the particular parts are variously bent. The reason
+  of which creasing we shall next examine; and here we must fetch our
+  information from the Mechanism or manner of proceeding in this operation;
+  which, as I have been inform'd, is no other then this.</p>
+
+  <p>They double all the Stuff that is to be water'd, that is, they crease
+  it just through the middle of it, the whole length of the piece, leaving
+  the right side of the Stuff inward, and placing the two edges, or
+  silvages just upon one another, and, as near as they can, place the wale
+  so in the doubling of it, that the wale of the one side may lie very near
+  parallel, or even with the wale of the other; for the nearer that posture
+  they lie, the greater will the watering appear; and the more obliquely,
+  or across to each other they lie, the smaller are the waves. Their way
+  for folding it for a great wale is thus: they take a Pin, and begin at
+  one side of the piece in any wale, and so moving it towards the other
+  side, thereby direct their hands to the opposite ends of the wale, and
+  then, as near as they can, place the two opposite ends of the same wale
+  together, and so double, or fold the whole piece, repeating this enquiry
+  with a Pin at every yard or two's distance through the whole length; then
+  they sprinkle it with water, and fold it the longways, placing between
+  every fold a piece of Pastboard, by which means all the wrong side of the
+  water'd Stuff becomes flat, and with little wales, and the wales on the
+  other side become the more protuberant; whence the creasings or angular
+  bendings of the wales become the more perspicuous. Having folded it in
+  this manner, they place it with an interjacent Pastboard into an hot
+  Press, where it is kept very violently prest, till it be dry and stiff;
+  by which means, the wales of either contiguous sides leave their own
+  impressions upon each other, as is very manifest by the second Figure,
+  where 'tis obvious enough, that the wale of the piece <i>ABCD</i> runs
+  parallel between the pricked lines <i>ef</i>, <i>ef</i>, <i>ef</i>, and
+  as manifest to discern the impressions upon
+  these wales, left by those that were prest upon them, which lying not
+  exactly parallel with them, but a little athwart them, as is denoted by
+  the lines of, <i>oooo</i>, <i>gh</i>, <i>gh</i>, <i>gh</i>, between which
+  the other wales did lie parallel; they are so variously, and irregularly
+  creas'd that being put into that shape when wet, and kept so till they be
+  drie, they so let each others threads, that the Moldings remain almost as
+  long as the Stuff lasts.</p>
+
+  <p>Hence it may appear to any one that attentively considers the Figure,
+  why the parts of the wale <i>a</i>, <i>a</i>, <i>a</i>, <i>a</i>,
+  <i>a</i>, <i>a</i>, should appear bright; and why the parts <i>b</i>,
+  <i>b</i>, <i>b</i>, <i>b</i>, <i>b</i>, <i>b</i>, <i>b</i>, should appear
+  shadowed, or dark; why some, as <i>d</i>, <i>d</i>, <i>d</i>, <i>d</i>,
+  <i>d</i>, <i>d</i>, should appear partly light, and partly dark: the
+  varieties of which reflections and shadows are the only cause of the
+  appearance of watering in Silks, or any other kind of Stuffs.</p>
+
+  <p>From the variety of reflection, may also be deduc'd the cause why a
+  small breez or gale of wind ruffling the surface of a smooth water, makes
+  it appear black; as also, on the other side, why the smoothing or
+  burnishing the surface of whitened Silver makes it look black; and
+  multitudes of other phænomena might hereby be solv'd, which are too many
+  to be here insisted on.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsVI" id="obsVI">VI</a>. <i>Of Small Glass Canes.</i></h3>
+
+  <p>That I might be satisfied, whether it were not possible to make an
+  <i>Artificial</i> pore as <i>small</i> as any <i>Natural</i> I had yet
+  found, I made several attemps with small <i>glass pipes</i>, melted in
+  the flame of a Lamp, and then very <i>suddenly</i> drawn out into a great
+  length. And, by <i>that means</i>, without much difficulty, I was able to
+  draw some almost as small as a <i>Cobweb</i>, which yet, with the
+<span class="sidenote">
+<a href="images/scheme-04.png" target="_blank"><i>Schem.</i> 4.</a>
+</span>
+  <i>Microscope</i>, I could plainly perceive
+  to be <i>perforated</i>, both by looking
+  on the <i>ends</i> of it, and by looking on it <i>against the light</i>
+  which was much the <i>easier way</i> to determine whether it were solid
+  or perforated; for, taking a small pipe of glass, and closing one end of
+  it, then filling it <i>half full</i> of water, and holding it <i>against
+  the light</i>, I could, by this means, very easily find what was the
+  <i>differing aspect</i> of a <i>solid</i> and a <i>perforated</i> piece
+  of glass; and so easily distingish, without seeing either end, whether
+  any <i>Cylinder</i> of glass I look'd on, were a <i>solid stick</i>, or a
+  <i>hollow cane</i>. And by this means, I could also presently judge of
+  any small <i>filament</i> of glass, whether it were <i>hollow</i> or
+  <i>not</i>, which would have been exceeding tedious to examine by looking
+  on the end. And many such like ways I was fain to make use of, in the
+  examining of divers other particulars related in this Book, which would
+  have been no easie task to have determined meerly by the more common way
+  of looking on, or viewing the Object. For, if we consider first, the very
+  <i>faint light</i> wherewith the object is enlightened, whence many
+  particles appear <i>opacous</i>, which when more enlightned, appear very
+  <i>transparent</i>, so that I was fain to <i>determine</i> its
+  <i>transparency</i> by one glass, and its <i>texture</i> by another.
+  Next, the <i>unmanageableness</i> of most <i>Objects</i>, by reason
+  of their <i>smalness</i>, 3. The
+  <i>difficulty of finding</i> the desired point, and of <i>placing</i> it
+  so, as to reflect the <i>light conveniently</i> for the Inquiry. Lastly,
+  ones being able to view it but with <i>one eye</i> at once, they will
+  appear no small <i>obstructions</i>, nor are they easily <i>remov'd</i>
+  without many <i>contrivances</i>. But to proceed, I could not find that
+  water, or some <i>deeply ting'd</i> liquors would in small ones rise so
+  high as one would expect; and the <i>highest</i> I have found it yet rise
+  in any of the pipes I have try'd, was to 21 <i>inches</i> above the level
+  of the water in the vessel: for though I found that in the small pipes it
+  would <i>nimbly enter</i> at first, and run about 6 or 7 <i>inches</i>
+  upwards; yet I found it then to move upwards <i>so slow</i>, that I have
+  not yet had the <i>patience</i> to observe it above that height of 21
+  <i>inches</i> (and that was in a pretty <i>large Pipe</i>, in comparison
+  of those I formerly mentioned; for I could observe the <i>progress</i> of
+  a <i>very deep ting'd liquor</i> in it with my <i>naked eye</i>, without
+  much trouble; whereas many of the <i>other pipes</i> were so <i>very
+  small</i>, that unless in a <i>convenient posture</i> to the light, I
+  could not perceive <i>them</i>:) But 'tis very probable, that a greater
+  <i>patience</i> and <i>assiduity</i> may discover the liquors to
+  <i>rise</i>, at least to remain <i>suspended</i>, at heights that I
+  should be loath now even to <i>ghess</i> at, if at least there be any
+  <i>proportion</i> kept between the height of the ascending liquor, and
+  the <i>bigness of the holes</i> of the pipes.</p>
+
+<p class="center"><b><i>An Attempt for the Explication of this Experiment.</i></b></p>
+
+  <p>My Conjecture, <i>That the unequal height of the surfaces of the
+  water, proceeded from the greater pressure made upon the water by the Air
+<span class="sidenote">
+<a href="images/scheme-04.png" target="_blank"><i>Schem.</i> 4.</a><br /><i>Fig.</i> 1.
+</span>
+  without the Pipes</i> ABC, <i>then by that within them</i>
+  I shall endeavour to
+  confirm from the truth of the two following <i>Propositions</i>:</p>
+
+  <p>The first of which is, <i>That an unequal pressure of the incumbent
+  Air, will cause an unequal height in the water's Surfaces</i>.</p>
+
+  <p>And the second is, <i>That in this experiment there is such an unequal
+  pressure</i>.</p>
+
+  <p>That the first is true, the following <i>Experiment</i> will evince.
+  For if you take any Vessel so contrived, as that you can at pleasure
+  either <i>increase</i> or <i>diminish</i> the <i>pressure</i> of the Air
+  upon this or that part of the <i>Superficies</i> of the <i>water</i>, the
+  <i>equality</i> of the height of those parts will presently be
+  <i>lost</i>; and that part of the <i>Superficies</i> that sustains the
+  <i>greater pressure</i>, will be <i>inferior</i> to that which undergoes
+  the <i>less</i>. A fit Vessel for this purpose, will be an inverted Glass
+  <i>Syphon</i>, such an one as is described in the <i>Sixth Figure</i>.
+  For if into it you put Water enough to fill it as high as <i>AB</i>, and
+  gently blow in at <i>D</i>, you shall <i>depress</i> the Superficies
+  <i>B</i>, and thereby <i>raise</i> the opposite Superficies <i>A</i> to a
+  <i>considerable height</i>, and by gently <i>sucking</i> you may produce
+  clean <i>contrary</i> effects.</p>
+
+  <p>Next, That there is such an <i>unequal pressure</i>, I shall prove
+  from this, <i>That there is a much greater incongruity of Air to Glass,
+  and some other Bodies, then there is of Water to the same</i>.</p>
+
+  <p>By <i>Congruity, I mean a property of a fluid Body, whereby any part
+  of it is readily united with any other part, either of itself, or of any
+  other Similar, fluid, or solid body: And by Incongruity a property of a
+  fluid, by which it is hindred from uniting with any dissimilar, fluid, or
+  solid Body.</i></p>
+
+  <p>This last property, any one that hath been observingly conversant
+  about fluid Bodies, cannot be ignorant of. For (not now to mention
+  several <i>Chymical Spirits</i> and <i>Oyls</i>, which will <i>very
+  hardly</i>, if at <i>all</i>, be brought to <i>mix</i> with one another;
+  insomuch that there may be found some 8 or 9, or more, several distinct
+  Liquors, which <i>swimming</i> one upon another, will not presently
+  <i>mix</i>) we need seek no further for Examples of this kind in
+  <i>fluids</i>, then to observe the <i>drops of rain</i> falling through
+  the <i>air</i> and the <i>bubbles of air</i> which are by any means
+  conveyed under the surface of the <i>water</i>; or a drop of common
+  <i>Sallet Oyl</i> swimming upon water. In all which, and many more
+  examples of this kind that might be enumerated, the <i>incongruity</i> of
+  two <i>fluids</i> is easily discernable. And as for the <i>Congruity</i>
+  or <i>Incongruity</i> of Liquids, with several kinds of <i>firm</i>
+  Bodies, they have long since been taken notice of, and called by the
+  Names of <i>Driness</i> and <i>Moisture</i> (though these two names are
+  not comprehensive enough, being commonly used to signifie only the
+  adhering or not adhering of <i>water</i> to some other <i>solid
+  Bodies</i>) of this kind we may observe that <i>water</i> will more
+  readily <i>wet some woods</i> then <i>others</i>; and that <i>water</i>,
+  let fall upon a <i>Feather</i>, the whiter side of a <i>Colwort</i>, and
+  some other leaves, or upon almost any <i>dusty</i>, <i>unctuous</i>, or
+  <i>resinous</i> superficies, will not <i>at all adhere</i> to them, but
+  easily <i>tumble off</i> from them, like a solid <i>Bowl</i>; whereas, if
+  dropt upon <i>Linnen</i>, <i>Paper</i>, <i>Clay</i>, <i>green Wood</i>,
+  &amp;c. it will not be taken off, without leaving some part of it behind
+  <i>adhering</i> to them. So <i>Quick-silver</i>, which will very
+  <i>hardly</i> be brought to <i>stick</i> to any <i>vegetable body</i>,
+  will <i>readily adhere</i> to, and <i>mingle</i> with, several clean
+  <i>metalline bodies</i>.</p>
+
+  <p>And that we may the better finde what the <i>cause</i> of
+  <i>Congruity</i> and <i>Incongruity</i> in bodies is, it will be
+  requisite to consider, First, what is the <i>cause</i> of
+  <i>fluidness</i>; And this, <i>I conceive</i>, to be nothing else but a
+  certain <i>pulse</i> or <i>shake</i> of <i>heat</i>; for Heat being
+  nothing else but a very <i>brisk</i> and <i>vehement agitation</i> of the
+  parts of a body (as I have elswhere made <i>probable</i>) the parts of a
+  body are thereby made so <i>loose</i> from one another, that they easily
+  <i>move any way</i>, and become <i>fluid</i>. That I may explain this a
+  little by a gross Similitude, let us suppose a dish of sand set upon some
+  body that is very much <i>agitated</i>, and shaken with some <i>quick</i>
+  and <i>strong vibrating motion</i>, as on a <i>Milstone</i> turn'd round
+  upon the under stone very violently whilst it is empty; or on a very
+  stiff <i>Drum</i>-head, which is vehemently or very nimbly beaten with
+  the Drumsticks. By this means, the sand in the dish, which before lay
+  like a <i>dull</i> and unactive body, becomes a perfect <i>fluid</i>; and
+  ye can no sooner make a <i>hole</i> in it with your finger, but it is
+  immediately <i>filled up again</i>, and the upper surface of it
+  <i>levell'd</i>. Nor can you <i>bury</i> a <i>light body</i>, as a piece
+  of Cork under it, but it presently <i>emerges</i> or <i>swims</i> as
+  'twere on the top; nor can you lay a <i>heavier</i> on the top of it, as
+  a piece of Lead, but it is immediately <i>buried</i> in
+  Sand, and (as 'twere) sinks to the bottom. Nor can you make a <i>hole</i>
+  in the side of the Dish, but the sand shall <i>run out</i> of it to a
+  <i>level</i>, not an <i>obvious property</i> of a fluid body, as such,
+  but this dos <i>imitate</i>; and all this meerly caused by the vehement
+  <i>agitation</i> of the conteining vessel; for by this means, <i>each</i>
+  sand becomes to have a <i>vibrative</i> or <i>dancing</i> motion, so as
+  no other heavier body can <i>rest</i> on it, unless <i>sustein'd</i> by
+  some other on either side: Nor will it suffer any Body to be
+  <i>beneath</i> it, unless it be a <i>heavier</i> then it self. Another
+  Instance of the strange <i>loosening</i> nature of a violent jarring
+  Motion, or a strong and nimble vibrative one, we may have from a piece of
+  <i>iron</i> grated on very strongly with a <i>file</i>: for if into that
+  a pin <i>screw'd</i> so firm and hard, that though it has a convenient
+  head to it, yet it can by no means be <i>unscrew'd</i> by the fingers;
+  if, I say, you attempt to unscrew this whilst <i>grated on by the
+  file</i>, it will be found to undoe and turn very <i>easily</i>. The
+  first of these Examples manifests, how a body actually <i>divided</i>
+  into small parts, becomes a <i>fluid</i>. And the latter manifests by
+  what means the agitation of heat so easily <i>loosens</i> and
+  <i>unties</i> the parts of <i>solid</i> and <i>firm</i> bodies. Nor need
+  we suppose heat to be any thing else, besides such a motion; for
+  supposing we could <i>Mechanically</i> produce such a one <i>quick</i>
+  and <i>strong</i> enough, we need not spend <i>fuel</i> to <i>melt</i> a
+  body. Now, that I do not speak this altogether groundless, I must refer
+  the Reader to the Observations I have made upon the shining sparks of
+  Steel, for there he shall find that <i>the same</i> effects are produced
+  upon small chips or parcels of Steel by the <i>flame</i>, and by <i>a
+  quick and violent motion</i>; and if the body of <i>steel</i> may be thus
+  melted (as I there shew it may) I think we have little reason to doubt
+  that almost <i>any other</i> may not also. Every Smith can inform one how
+  quickly both his <i>File</i> and the <i>Iron</i> grows <i>hot</i> with
+  <i>filing</i>, and if you <i>rub</i> almost any two <i>hard</i> bodies
+  together, they will do the same: And we know, that a sufficient degree of
+  heat causes <i>fluidity</i>, in some bodies much sooner, and in others
+  later; that is, the parts of the body of some are so <i>loose</i> from
+  one another, and so <i>unapt to cohere</i>, and so <i>minute</i> and
+  <i>little</i>, that a very <i>small</i> degree of agitation keeps them
+  always in the <i>state of fluidity</i>. Of this kind, I suppose, the
+  <i>Æther</i>, that is the <i>medium</i> or <i>fluid</i> body, in which
+  all other bodies do as it were swim and move; and particularly, the
+  <i>Air</i>, which seems nothing else but a kind of <i>tincture</i> or
+  <i>solution</i> of terrestrial and aqueous particles <i>dissolv'd</i>
+  into it, and agitated by it, just as the <i>tincture</i> of
+  <i>Cocheneel</i> is nothing but some finer <i>dissoluble</i> parts of
+  that Concrete lick'd up or <i>dissolv'd</i> by the <i>fluid</i> water.
+  And from this Notion of it, we may easily give a more Intelligible reason
+  how the Air becomes so capable of <i>Rarefaction</i> and
+  <i>Condensation</i>. For, as in <i>tinctures</i>, one grain of some
+  <i>strongly tinging</i> substance may <i>sensibly</i> colour some
+  <i>hundred thousand</i> grains of <i>appropriated</i> Liquors, so as
+  every <i>drop</i> of it has its proportionate share, and be sensibly
+  ting'd, as I have try'd both with <i>Logwood</i> and <i>Cocheneel</i>:
+  And as some few grains of <i>Salt</i> is able to infect as great a
+  quantity, as may be found by <i>præcipitations</i>, though not so easily
+  by the <i>sight</i> or <i>taste</i>; so the <i>Air</i>, which seems to be
+  but as 'twere a <i>tincture</i> or <i>saline substance, dissolv'd and
+  agitated by the fluid and agil Æther</i>, may disperse and
+  <i>expand</i> it self into a <i>vast space</i>, if it have room enough,
+  and infect, as it were, every part of that space. But, as on the other
+  side, if there be but some <i>few grains</i> of the liquor, it may
+  <i>extract all</i> the colour of the tinging substance, and may
+  <i>dissolve</i> all the Salt, and thereby become <i>much more
+  impregnated</i> with those substances, so may <i>all</i> the air that
+  sufficed in a <i>rarfy'd state</i> to fill some <i>hundred thousand</i>
+  spaces of Æther, be compris'd in only <i>one</i>, but in a position
+  proportionable <i>dense</i>. And though we have not yet found out such
+  <i>strainers</i> for Tinctures and Salts as we have for the Air, being
+  yet unable to <i>separate</i> them from their dissolving liquors by any
+  kind of <i>filtre</i>, without <i>præcipitation</i>, as we are able to
+  <i>separate</i> the Air from the Æther by <i>Glass</i>, and several other
+  bodies. And though we are yet unable and ignorant of the ways of
+  <i>præcipitating</i> Air out of the Æther as we can Tinctures, and Salts
+  out of several <i>dissolvents</i>; yet neither of these seeming
+  <i>impossible</i> from the nature of the things, nor so <i>improbable</i>
+  but that some happy future industry may find out ways to effect them;
+  nay, further, since we find that Nature <i>does really perform</i>
+  (though by what means we are not certain) both these actions, namely, by
+  <i>præcipitating</i> the Air in Rain and Dews, and by supplying the
+  Streams and Rivers of the World with fresh water, <i>strain'd</i> through
+  secret subterraneous Caverns: And since, that in very many other
+  <i>proprieties</i> they do so exactly <i>seem</i> of the <i>same
+  nature</i>; till further observations or tryals do inform us of the
+  <i>contrary</i>, we may <i>safely enough conclude</i> them of the <i>same
+  kind</i>. For it seldom happens that any two natures have so many
+  properties <i>coincident</i> or the <i>same</i>, as I have observ'd
+  Solutions and Air to have, and to be <i>different</i> in the rest. And
+  therefore I think it neither <i>impossible</i>, <i>irrational</i>, nay
+  nor <i>difficult</i> to be able to <i>predict</i> what is <i>likely</i>
+  to happen in other particulars also, besides those which
+  <i>Observation</i> or <i>Experiment</i> have declared thus or thus;
+  especially, if the <i>circumstances</i> that do often very much conduce
+  to the variation of the effects be duly <i>weigh'd</i> and
+  <i>consider'd</i>. And indeed, were there not a <i>probability</i> of
+  this, our <i>inquiries</i> would be <i>endless</i>, our <i>tryals
+  vain</i>, and our greatest <i>inventions</i> would be nothing but the
+  meer <i>products</i> of <i>chance</i>, and not of <i>Reason</i>; and,
+  like <i>Mariners</i> in an Ocean, destitute both of a <i>Compass</i> and
+  the sight of the <i>Celestial guids</i>, we might indeed, <i>by
+  chance</i>, Steer <i>directly</i> towards our desired Port, but 'tis <i>a
+  thousand to one</i> but we <i>miss</i> our aim. But to proceed, we may
+  hence also give a plain reason, how the Air comes to be <i>darkned</i> by
+  <i>clouds</i>, &amp;c. which are nothing but a kind of
+  <i>precipitation</i>, and how those <i>precipitations</i> fall down in
+  <i>Showrs</i>. Hence also could I very easily, and I think truly, deduce
+  the cause of the curious <i>sixangular figures</i> of Snow, and the
+  appearances of <i>Haloes, &amp;c.</i> and the sudden <i>thickning</i> of
+  the Sky with Clouds, and the <i>vanishing</i> and <i>disappearing</i> of
+  those Clouds again; for all these things may be very easily
+  <i>imitated</i> in a <i>glass of liquor</i>, with some slight <i>Chymical
+  preparations</i> as I have often try'd, and may somewhere else more
+  largely relate, but have not now time to set them down. But to proceed,
+  there are other bodies that consist of particles more <i>Gross</i>, and
+  of a more <i>apt</i> figure for <i>cohesion</i>, and this requires
+  <i>somewhat greater</i> agitation; such, I suppose <img
+  src="images/mercury.png" alt="Mercury"  />,
+  <i>fermented vinous</i> <i>Spirits</i>, several
+  <i>Chymical Oils</i>, which are much of kin to those Spirits, &amp;c.
+  Others yet require a <i>greater</i>, as <i>water</i>, and so others
+  <i>much greater</i>, for almost infinite degrees: For, I suppose there
+  are very <i>few</i> bodies in the world that may not be made
+  <i>aliquatenus</i> fluid, by <i>some</i> or <i>other</i> degree of
+  agitation or heat.</p>
+
+  <p>Having therefore in short set down my Notion of a Fluid body, I come
+  in the next place to consider what <i>Congruity</i> is; and this, as I
+  said before, being a <i>Relative property</i> of a fluid, whereby it may
+  be said to be <i>like</i> or <i>unlike</i> to this or that other body,
+  whereby it <i>does</i> or <i>does not mix</i> with this or that body. We
+  will again have recourse to our former Experiment, though but a rude one;
+  and here if we mix in the dish <i>several kinds</i> of sands, some of
+  <i>bigger</i>, others of <i>less</i> and finer bulks, we shall find that
+  by the agitation <i>the fine sand</i> will <i>eject</i> and <i>throw
+  out</i> of it self all those <i>bigger</i> bulks of small <i>stones</i>
+  and the like, and those will <i>be gathered</i> together all into
+  <i>one</i> place; and if there be <i>other</i> bodies in it of other
+  natures, those also will be <i>separated</i> into a place by themselves,
+  and <i>united</i> or <i>tumbled</i> up together. And though this do not
+  come up to the <i>highest property</i> of <i>Congruity</i>, which is a
+  <i>Cohæsion</i> of the parts of the fluid together, or a kind of
+  <i>attraction</i> and <i>tenacity</i>, yet this does as 'twere
+  <i>shadow</i> it out, and somewhat resemble it; for just after the same
+  manner, I suppose the <i>pulse</i> of heat to <i>agitate</i> the small
+  parcels of matter, and those that are of a <i>like bigness</i>, and
+  <i>figure</i>, and <i>matter</i>, will <i>hold</i>, or <i>dance</i>
+  together, and those which are of a <i>differing</i> kind will be
+  <i>thrust</i> or <i>shov'd</i> out from between them; for particles that
+  are <i>similar</i>, will, like so many <i>equal musical strings equally
+  stretcht</i>, vibrate together in a kind of <i>Harmony</i> or
+  <i>unison</i>; whereas others that are <i>dissimilar</i>, upon what
+  account soever, unless the disproportion be otherwise counter-ballanc'd,
+  will, like so many <i>strings out of tune</i> to those unisons, though
+  they have the same agitating <i>pulse</i>, yet make quite
+  <i>differing</i> kinds of <i>vibrations</i> and <i>repercussions</i>, so
+  that though they may be both mov'd, yet are their <i>vibrations</i> so
+  <i>different</i>, and so <i>untun'd</i>, as 'twere to each other, that
+  they <i>cross</i> and <i>jar</i> against each other, and consequently,
+  <i>cannot agree</i> together, but <i>fly back</i> from each other to
+  their similar particles. Now, to give you an instance how the
+  <i>disproportion</i> of some bodies in one respect, may be
+  <i>counter-ballanc'd</i> by a <i>contrary disproportion</i> of the same
+  body in another respect, whence we find that the subtil <i>vinous
+  spirit</i> is <i>congruous</i>, or does readily <i>mix</i> with
+  <i>water</i>, which in many properties is of a very <i>differing
+  nature</i>, we may consider that a <i>unison</i> may be made either by
+  two <i>strings</i> of the same <i>bigness</i>, <i>length</i>, and
+  <i>tension</i>, or by two strings of the same <i>bigness</i>, but of
+  <i>differing length</i>, and a <i>contrary differing tension</i>, or
+  <i>3ly.</i> by two strings of <i>unequal length</i> and <i>bigness</i>,
+  and of a <i>differing tension</i>, or of <i>equal length</i>, and
+  <i>differing bigness</i> and <i>tension</i>, and several other such
+  varieties. To which <i>three properties</i> in <i>strings</i>, will
+  correspond <i>three proprieties</i> also in <i>sand</i>, or the
+  <i>particles</i> of bodies, their <i>Matter</i> or <i>Substance</i>,
+  their <i>Figure</i> or <i>Shape</i>, and their <i>Body</i> or
+  <i>Bulk</i>. And from the <i>varieties</i> of these <i>three</i>, may
+  arise <i>infinite varieties</i> in fluid bodies, though all agitated by
+  the <i>same pulse</i> or <i>vibrative</i> motion. And there may be as
+  many ways of making Harmonies and Discords with these, as
+  there may be with <i>musical strings</i>. Having therefore seen what is
+  the cause of Congruity or Incongruity, those relative properties of
+  fluids, we may, from what has been said, very easily collect, what is the
+  <i>reason</i> of those Relative proprieties also between <i>fluid
+  bodies</i> and <i>solid</i>; for since all bodies consist of
+  <i>particles</i> of such a <i>Substance</i>, <i>Figure</i>, and
+  <i>Bulk</i>; but in some they are <i>united</i> together more
+  <i>firmly</i> then to be <i>loosened</i> from each other by every
+  <i>vibrative</i> motion (though I imagine that there is no body in the
+  world, but that some degree of agitation may, as I hinted before, agitate
+  and loosen the particles so as to make them fluid) those <i>cohering</i>
+  particles may <i>vibrate</i> in the same manner almost as those that are
+  <i>loose</i> and become <i>unisons</i> or <i>discords</i>, as I may so
+  speak, to them. Now that the <i>parts</i> of all <i>bodies</i>, though
+  never so <i>solid</i>, do yet <i>vibrate</i>, I think we need go no
+  further for proof, then that <i>all</i> bodies have some <i>degrees</i>
+  of <i>heat</i> in them, and that there has not been yet found any thing
+  <i>perfectly cold</i>: Nor can I believe indeed that there is any such
+  thing in Nature, as a body whose particles are at <i>rest</i>, or
+  <i>lazy</i> and <i>unactive</i> in the great <i>Theatre</i> of the
+  <i>World</i>, it being quite <i>contrary</i> to the grand <i>Oeconomy</i>
+  of the Universe. We see therefore what is the reason of the
+  <i>sympathy</i> or uniting of some bodies together, and of the
+  <i>antipathy</i> or flight of others from each other: For
+  <i>Congruity</i> seems nothing else but a <i>Sympathy</i>, and
+  <i>Incongruity</i> an <i>Antipathy</i> of bodies, hence <i>similar</i>
+  bodies once <i>united</i> will not <i>easily part</i>, and
+  <i>dissimilar</i> bodies once <i>disjoyn'd</i> will not <i>easily
+  unite</i> again; from hence may be very easily deduc'd the reason of the
+  <i>suspension</i> of <i>water</i> and <i>Quick-silver</i> above their
+  usual <i>station</i>, as I shall more at large anon shew.</p>
+
+  <p>These properties therefore (alwayes the concomitants of fluid bodies)
+  produce these following visible <i>Effects</i>:</p>
+
+  <p>First, They <i>unite</i> the parts of a fluid to its <i>similar</i>
+  Solid, or keep them <i>separate</i> from its <i>dissimilar</i>. Hence
+  <i>Quick-silver</i> will (as we noted before) <i>stick</i> to
+  <i>Gold</i>, <i>Silver</i>, <i>Tin</i>, <i>Lead</i>, &amp;c. and
+  <i>unite</i> with them: but <i>roul</i> off from <i>Wood</i>,
+  <i>Stone</i>, <i>Glass</i>, &amp;c. if never so little scituated out of
+  its <i>horizontal level</i>; and <i>water</i> that will <i>wet salt</i>
+  and <i>dissolve</i> it, will <i>slip</i> off from <i>Tallow</i>, or the
+  like, without at all <i>adhering</i>; as it may likewise be observed to
+  do upon a <i>dusty</i> superficies. And next they cause the parts of
+  <i>homogeneal fluid</i> bodies readily to <i>adhere</i> together and
+  <i>mix</i>, and of <i>heterogeneal</i>, to be exceeding <i>averse</i>
+  thereunto. Hence we find, that <i>two</i> small <i>drops</i> of
+  <i>water</i>, on any superficies they can roul on, will, if they chance
+  to touch each other, <i>readily unite</i> and <i>mix</i> into one
+  3<sup>d</sup> <i>drop</i>: The like may be observed with two small
+  <i>Bowls</i> of <i>Quick-silver</i> upon a Table or Glass, provided their
+  surfaces be not <i>dusty</i>; and with two drops of <i>Oyl</i> upon fair
+  water, <i>&amp;c</i>. And further, <i>water</i> put unto <i>wine</i>,
+  <i>salt water</i>, <i>vinegar</i>, <i>spirit</i> of <i>wine</i>, or the
+  like, does immediately (especially if they be shaken together)
+  <i>disperse</i> it self all over them. Hence, on the contrary, we also
+  find, that <i>Oyl of Tartar</i> poured upon <i>Quick-silver,</i> and
+  <i>Spirit of Wine</i> on that <i>Oyl</i>, and <i>Oyl of Turpentine</i> on
+  that <i>Spirit</i>, and <i>Air</i> upon that <i>Oyl</i>, though they be
+  stopt closely up into a Bottle, and <i>shaken</i> never so much, they
+  will by no means long suffer any of their bigger parts to be
+  <i>united</i> or included within any of the other Liquors
+  (by which recited Liquors, may be plainly enough represented the four
+  <i>Peripatetical Elements</i>, and the more subtil <i>Æther</i> above
+  all.) From this property 'tis, that a drop of <i>water</i> does not
+  mingle with, or vanish into <i>Air</i>, but is <i>driven</i> (by that
+  Fluid equally protruding it on every side) and forc't into as little a
+  space as it can possibly be contained in, namely, into a <i>Round
+  Globule</i>. So likewise a little <i>Air</i> blown under the
+  <i>water</i>, is <i>united</i> or thrust into a <i>Bubble</i> by the
+  ambient water. And a parcel of <i>Quick-silver</i> enclosed with
+  <i>Air</i>, <i>Water</i>, or almost any other <i>Liquor</i>, is
+  <i>formed</i> into a <i>round Ball</i>.</p>
+
+  <p>Now the cause why all these included Fluids, newly mentioned, or as
+  many others as are wholly included within a heterogeneous fluid, are not
+  <i>exactly</i> of a <i>Spherical Figure</i> (seeing that if caused by
+  these Principles only, it could be of no other) must proceed from some
+  other kind of <i>pressure</i> against the two opposite flatted sides.
+  This <i>adventitious</i> or <i>accidental pressure</i> may proceed from
+  <i>divers causes</i>, and accordingly must <i>diversifie</i> the Figure
+  of the included heterogeneous fluid: For seeing that a body may be
+  included either with a fluid only, or only with a solid, or partly with a
+  fluid, and partly with a solid, or partly with one fluid, and partly with
+  another; there will be found a very great variety of the terminating
+  <i>surfaces</i>, much differing from a <i>Spherical</i>, according to the
+  various resistance or pressure that belongs to each of these encompassing
+  bodies.</p>
+
+  <p>Which Properties may in general be deduced from two heads, <i>viz.</i>
+  <i>Motion</i>, and <i>Rest</i>. For, either this Globular Figure is
+  altered by a <i>natural Motion</i>, such as is <i>Gravity</i>, or a
+  <i>violent</i>, such as is any <i>accidental motion</i> of the fluids, as
+  we see in the <i>wind</i> ruffling up the water, and the <i>purlings</i>
+  of <i>Streams</i>, and <i>foaming</i> of <i>Catarracts</i>, and the like.
+  Or thirdly, By the <i>Rest</i>, <i>Firmness</i> and <i>Stability</i> of
+  the ambient <i>Solid</i>. For if the including <i>Solid</i> be of an
+  <i>angular</i> or any other <i>irregular</i> Form, the included
+  <i>fluid</i> will be near of the <i>like</i>, as a Pint-<i>Pot</i> full
+  of <i>water</i>, or a <i>Bladder</i> full of <i>Air</i>. And next, if the
+  including or included fluid have a greater <i>gravity</i> one than
+  another, then will the <i>globular</i> Form be deprest into an
+  <i>Elliptico-spherical</i>: As if, for example, we suppose the Circle
+  <i>ABCD</i>, in the <i>fourth Figure</i>, to represent a <i>drop of
+  water</i>, <i>Quick-silver</i>, or the like, included with the <i>Air</i>
+  or the like, which supposing there were no <i>gravity</i> at all in
+  either of the <i>fluids</i>, or that the <i>contained</i> and
+  <i>containing</i> were of the <i>same weight,</i> would be <i>equally
+  comprest</i> into an exactly <i>spherical</i> body (the ambient fluid
+  <i>forcing equally</i> against every side of it.) But supposing either a
+  greater <i>gravity</i> in the included, by reason whereof the parts of it
+  being <i>prest</i> from <i>A</i> towards <i>B</i>, and thereby the whole
+  put into <i>motion</i>, and that <i>motion</i> being <i>hindred</i> by
+  the <i>resistance</i> of the <i>subjacent</i> parts of the ambient, the
+  <i>globular</i> Figure <i>ADBC</i> will be <i>deprest</i> into the
+  <i>Elliptico-spherical</i>, <i>EGFH</i>. For the side <i>A</i> is
+  <i>detruded</i> to <i>E</i> by the <i>Gravity</i>, and <i>B</i> to
+  <i>F</i> by the <i>resistance</i> of the subjacent medium: and therefore
+  <i>C</i> must necessarily be thrust to <i>G</i>; and <i>D</i> to
+  <i>H</i>. Or else, supposing a greater <i>gravity</i> in the
+  <i>ambient</i>, by whose more then ordinary <i>pressure</i> against the
+  under side of the included globule; <i>B</i> will be forced to <i>F</i>,
+  and by its <i>resistance</i> of the motion <i>upwards</i>, the
+  side <i>A</i> will be <i>deprest</i> to <i>E</i>, and therefore <i>C</i>
+  being thrust to <i>G</i> and <i>D</i> to <i>H</i>; the <i>globular</i>
+  Figure by this means also will be made an <i>Elliptico-spherical</i>.
+  Next if a fluid be included <i>partly</i> with one, and <i>partly</i>
+  with another fluid, it will be found to be shaped <i>diversly</i>,
+  according to the proportion of the <i>gravity</i> and <i>incongruity</i>
+  of the 3 <i>fluids</i> one to another: As in the <i>second Figure</i>,
+  let the upper <i>MMM</i> be <i>Air</i>, the middle <i>LMNO</i> be common
+  <i>Oyl</i>, the lower <i>OOO</i> be <i>Water</i>, the <i>Oyl</i> will be
+  form'd, not into a <i>spherical</i> Figure, such as is represented by the
+  <i>pricked Line</i>, but into such a Figure as LMNO, whose side LMN will
+  be of a flatter <i>Elliptical</i> Figure, by reason of the great
+  disproportion between the <i>Gravity</i> of <i>Oyl</i> and <i>Air</i>,
+  and the side LOM of a rounder, because of the smaller difference between
+  the weight of <i>Oyl</i> and <i>Water</i>. Lastly, The <i>globular</i>
+  Figure will be changed, if the <i>ambient</i> be partly <i>fluid</i> and
+  partly <i>solid</i>. And here the termination of the incompassed
+  <i>fluid</i> towards the incompassing is shap'd according to the
+  proportion of the congruity or incongruity of the <i>fluids</i> to the
+  <i>solids</i>, and of the gravity and incongruity of the <i>fluids</i>
+  one to another. As suppose the subjacent <i>medium</i> that hinders an
+  included fluids descent, be a <i>solid</i>, as let KI, in the <i>fourth
+  Figure</i>, represent the smooth superficies of a <i>Table</i>; EGFH, a
+  parcel of <i>running Mercury</i>; the side GFH will be more flatted,
+  according to the proportion of the incongruity of the <i>Mercury</i> and
+  <i>Air</i> to the <i>Wood</i>, and of the <i>gravity</i> of
+  <i>Mercury</i> and <i>Air</i> one to another; The side GEH will likewise
+  be a little more deprest by reason the subjacent parts are now at rest,
+  which were before in motion.</p>
+
+  <p>Or further in the <i>third figure</i>, let AILD represent an including
+  <i>solid</i> medium of a cylindrical shape (as suppose a small <i>Glass
+  Jar</i>) Let FGEMM represent a contain'd <i>fluid</i>, as water; this
+  towards the bottom and sides, is figured according to the concavity of
+  the <i>Glass</i>: But its upper <i>Surface</i>, (which by reason of its
+  gravity, (not considering at all the Air above it, and so neither the
+  congruity or incongruity of either of them to the Glass) should be
+  terminated by part of a <i>Sphere</i> whose diameter should be the same
+  with that of the earth, which to our sense would appear a straight
+  <i>Line</i>, as FGE, Or which by reason of its having a greater congruity
+  to Glass than Air has, (not considering its Gravity) would be thrust into
+  a <i>concave Sphere</i>, as CHB, whose diameter would be the same with
+  that of the concavity of the Vessel:) Its upper Surface, I say, by reason
+  of its having a greater gravity then the Air, and having likewise a
+  greater congruity to Glass then the Air has, is terminated, by a
+  <i>concave Elliptico-spherical Figure</i>, as CKB. For by its congruity
+  it easily conforms it self, and adheres to the Glass, and constitutes as
+  it were one containing body with it, and therefore should thrust the
+  contained Air on that side it touches it, into a <i>spherical</i> Figure,
+  as BHC, but the motion of Gravity depressing a little the Corners B and
+  C, reduces it into the aforesaid Figure CKB. Now that it is the greater
+  congruity of one of the two <i>contiguous fluids</i>, then of the other,
+  to the containing <i>solid</i>, that causes the separating surfaces to be
+  thus or thus figured: And that it is not because this or that figurated
+  surface is more proper, natural, or peculiar to one of these
+  fluid bodies, then to the other, will appear from this; that the same
+  <i>fluids</i> will by being put into differing <i>solids</i>, change
+  their <i>surfaces</i>. For the same water, which in a Glass or wooden
+  Vessel will have a concave surface upwards, and will rise higher in a
+  smaller then a greater Pipe, the same water, I say, in the same Pipes
+  greased over or oyled, will produce quite contrary effects; for it will
+  have a <i>protuberant</i> and <i>convex</i> surface upwards, and will not
+  rise so high in small, as in bigger Pipes: Nay, in the very same solid
+  Vessel, you may make the very same two contiguous <i>Liquids</i> to alter
+  their Surfaces; for taking a small Wine-glass, or such like Vessel, and
+  pouring water gently into it, you shall perceive the <i>surface</i> of
+  the water all the way <i>concave</i>, till it rise even with the top,
+  when you shall find it (if you gently and carefully pour in more) to grow
+  very <i>protuberant</i> and <i>convex</i>; the reason of which is plain,
+  for that the <i>solid</i> sides of the containing body are no longer
+  extended, to which the water does more readily adhere then the air; but
+  it is henceforth to be included with air, which would reduce it into a
+  <i>hemisphere</i>, but by reason of its <i>gravity</i>, it is flatted
+  into an <i>Oval</i>. <i>Quicksilver</i> also which to <i>Glass</i> is
+  more incongruous then <i>Air</i> (and thereby being put into a
+  <i>Glass-pipe</i>, will not adhere to it, but by the more <i>congruous
+  air</i> will be forced to have a very <i>protuberant</i> surface, and to
+  rise higher in a greater then a lesser Pipe) this <i>Quicksilver</i> to
+  clean <i>Metal</i>, especially to <i>Gold</i>, <i>Silver</i>, <i>Tin</i>,
+  <i>Lead</i>, &amp;c. <i>Iron</i> excepted, is more <i>congruous</i> then
+  <i>Air</i>, and will not only stick to it, but have a <i>concave</i>
+  Surface like <i>water</i>, and rise higher in a less, then in a greater
+  Pipe.</p>
+
+  <p>In all these Examples it is evident, that there is an
+  <i>extraordinary</i> and <i>adventitious force</i>, by which the
+  <i>globular</i> Figure of the contained <i>heterogeneous</i> fluid is
+  altered; neither can it be imagined, how it should otherwise be of any
+  other Figure then <i>Globular</i>: For being by the <i>heterogeneous</i>
+  fluid equally <i>protruded</i> every way, whatsoever part is
+  <i>protuberant</i>, will be thereby <i>deprest</i>. From this cause it
+  is, that in its effects it does very much resemble a <i>round Spring</i>
+  (such as a <i>Hoop</i>.) For as in a <i>round Spring</i> there is
+  required an additional <i>pressure</i> against two opposite sides, to
+  reduce it into an <i>Oval</i> Form, or to force it in between the sides
+  of a <i>Hole,</i> whose <i>Diameter</i> is less then that of the
+  <i>Spring</i>, there must be a considerable force or <i>protusion</i>
+  against <i>the concave</i> or inner side of the <i>Spring</i>; So to
+  alter this <i>spherical</i> constitution of an included fluid body, there
+  is required more pressure against opposite sides to reduce it into an
+  <i>Oval</i>; and, to press it into an <i>Hole</i> less in <i>Diameter</i>
+  then it self, it requires a greater <i>protrusion</i> against all the
+  other sides, What degrees of force are requisite to reduce them into
+  longer and longer <i>Ovals</i>, or to press them into less and less
+  <i>holes</i>, I have not yet experimentally calculated; but thus much by
+  experiment I find in general, that there is alwayes required a greater
+  pressure to close them into longer <i>Ovals</i>, or protude them into
+  smaller <i>holes</i>. The necessity and reason of this, were it
+  requisite, I could easily explain: but being not so necessary, and
+  requiring more room and time then I have for it at present, I shall here
+  omit it; and proceed to shew, that this may be presently found true, if
+  Experiment be made with a <i>round Spring</i> (the way of
+  making which trials is <i>obvious</i> enough.) And with the fluid bodies
+  of <i>Mercury</i>, <i>Air</i>, <i>&amp;c</i>, the way of trying which,
+  will be somewhat more difficult; and therefore I shall in brief describe
+  it. He therefore that would try with <i>Air</i>, must first be provided
+  of a <i>Glass-pipe</i>, made of the shape of that in the <i>fifth
+  Figure</i>, whereof the side AB, represents a straight <i>Tube</i> of
+  about three foot long, C, represents another part of it, which consists
+  of a <i>round Bubble</i>; so ordered, that there is left a <i>passage</i>
+  or <i>hole</i> at the top, into which may be fastened with <i>cement</i>
+  several <i>small Pipes</i> of determinate <i>cylindrical</i> cavities: as
+  let <i>hollow</i> of</p>
+
+<pre>
+  F.       1/4
+  G.       1/6
+  H.       1/8
+  I.  be   1/12   of an inch.
+  K.       1/16
+  L.       1/24
+  M.       1/32
+  &amp;c----
+</pre>
+  <p>There may be added as many more, as the Experimenter shall think fit,
+  with holes continually decreasing by known quantities, so far as his
+  senses are able to help him; I say, so far, because there may be made
+  <i>Pipes</i> so small that it will be impossible to perceive the
+  <i>perforation</i> with ones naked eye, though by the help of a
+  <i>Microscope</i>, it may easily enough be perceived: Nay, I have made a
+  <i>Pipe</i> perforated from end to end, so small, that with my naked eye
+  I could very hardly see the body of it, insomuch that I have been able to
+  knit it up into a knot without breaking: And more accurately examining
+  one with my <i>Microscope</i>, I found it not so big as a sixteenth part
+  of one of the smaller hairs of my head which was of the smaller and finer
+  sort of hair, so that sixteen of these <i>Pipes</i> bound faggot-wise
+  together, would but have equalized one single hair; how small therefore
+  must its <i>perforation</i> be? It appearing to me through the
+  <i>Microscope</i> to be a proportionably <i>thick-sided Pipe</i>.</p>
+
+  <p>To proceed then, for the trial of the Experiment, the Experimenter
+  must place the <i>Tube</i> AB, perpendicular, and fill the <i>Pipe</i> F
+  (cemented into the hole E) with water, but leave the <i>bubble</i> C full
+  of <i>Air</i>, and then gently pouring in water into the Pipe AB, he must
+  observe diligently how high the water will rise in it before it protrude
+  the <i>bubble</i> of Air C, through the narrow passage of F, and denote
+  exactly the height of the <i>Cylinder</i> of water, then cementing in a
+  second Pipe as G, and filling it with water; he may proceed as with the
+  former, denoting likewise the height of the <i>Cylinder</i> of water,
+  able to protrude the <i>bubble</i> C through the passage of G, the like
+  may he do with the next <i>Pipe</i>, and the next, <i>&amp;c.</i> as far
+  as he is able: then comparing the several heights of the
+  <i>Cylinders</i>, with the several <i>holes</i> through which each
+  <i>Cylinder</i> did force the <i>air</i> (having due regard to the
+  <i>Cylinders</i> of water in the small <i>Tubes</i>) it will be very
+  easie to determine, what force is requisite to press the <i>Air</i> into
+  such and such <i>a hole</i>, or (to apply it to our present experiment)
+  how much of the pressure of the <i>Air</i> is
+  taken off by its ingress into smaller and smaller <i>holes</i>. From the
+  application of which to the entring of the <i>Air</i> into the bigger
+  <i>hole</i> of the <i>Vessel</i>, and into the smaller <i>hole</i> of the
+  <i>Pipe</i>, we shall clearly find, that there is a greater pressure of
+  the air upon the water in the <i>Vessel</i> or greater <i>pipe</i>, then
+  there is upon that in the lesser <i>pipe</i>: For since the pressure of
+  the <i>air</i> every way is found to be equal, that is, as much as is
+  able to press up and sustain a <i>Cylinder</i> of <i>Quicksilver</i> of
+  two foot and a half high, or thereabouts; And since of this pressure so
+  many more degrees are required to force the <i>Air</i> into a smaller
+  then into a greater <i>hole</i> that is full of a more congruous fluid.
+  And lastly, since those degrees that are requisite to press it in, are
+  thereby taken off from the <i>Air</i> within, and the <i>Air</i> within
+  left with so many degrees of pressure less then the <i>Air</i> without;
+  it will follow, that the <i>Air</i> in the less <i>Tube</i> or
+  <i>pipe</i>, will have less pressure against the superficies of the
+  <i>water</i> therein, then the <i>Air</i> in the bigger: which was the
+  minor Proposition to be proved.</p>
+
+  <p>The Conclusion therefore will necessarily follow, <i>viz.</i> That
+  <i>this unequal pressure of the Air caused by its ingress into unequal
+  holes, is a cause sufficient to produce this effect, without the help of
+  any other concurrent</i>; therefore is probably the principal (if not the
+  only) cause of these <i>Phænomena</i>.</p>
+
+  <p>This therefore being thus explained, there will be divers
+  <i>Phænomena</i> explicable thereby, as, the rising of <i>Liquors</i> in
+  a <i>Filtre</i>, the rising of <i>Spirit of Wine</i>, <i>Oyl</i>,
+  <i>melted Tallow</i>, <i>&amp;c.</i> in the <i>Week</i> of a <i>Lamp</i>,
+  (though made of small <i>Wire</i>, <i>Threeds</i> of <i>Asbestus</i>,
+  <i>Strings</i> of <i>Glass</i>, or the like) the rising of <i>Liquors</i>
+  in a <i>Spunge</i>, piece of <i>Bread</i>, <i>Sand</i>, <i>&amp;c.</i>
+  perhaps also the ascending of the <i>Sap</i> in <i>Trees</i> and
+  <i>Plants</i>, through their small, and some of them <i>imperceptible
+  pores</i>, (of which I have said more, on another occasion) at least the
+  passing of it out of the earth into their roots. And indeed upon the
+  consideration of this Principle, multitudes of other uses of it occurr'd
+  to me, which I have not yet so well examined and digested as to propound
+  for <i>Axioms</i>, but only as <i>Queries</i> and <i>Conjectures</i>
+  which may serve as <i>hints</i> toward some further
+  <i>discoveries</i>.</p>
+
+  <p>As first, Upon the consideration of the <i>congruity</i> and
+  <i>incongruity</i> of Bodies, as to <i>touch</i>, I found also the like
+  <i>congruity</i> and <i>incongruity</i> (if I may so speak) as to the
+  <i>Transmitting</i> of the <i>Rates</i> of Light: For as in this regard,
+  <i>water</i> (not now to mention other Liquors) seems nearer of affinity
+  to <i>Glass</i> then <i>Air</i>, and <i>Air</i> then <i>Quicksilver</i>:
+  whence an <i>oblique Ray</i> out of <i>Glass</i>, will pass into
+  <i>water</i> with very little <i>refraction</i> from the
+  <i>perpendicular</i>, but none out of <i>Glass</i> into <i>Air</i>,
+  excepting a <i>direct</i>, will pass without a very great refraction from
+  the perpendicular, nay any oblique Ray under thirty degrees, will not be
+  admitted into the Air at all. And <i>Quicksilver</i> will neither admit
+  oblique or direct, but reflects all; seeming, as to the transmitting of
+  the Raies of Light, to be of a quite differing constitution, from that of
+  <i>Air</i>, <i>Water</i>, <i>Glass</i>, <i>&amp;c.</i> and to resemble
+  most those opacous and strong reflecting bodies of Metals: So also as to
+  the property of cohesion or congruity, Water seems to keep the same
+  order, being more congruous to Glass then Air, and Air
+  then Quicksilver.</p>
+
+  <p>A Second thing (which was hinted to me, by the consideration of the
+  included fluids globular form, caused by the protrusion of the ambient
+  heterogeneous fluid) was, whether the <i>Phænomena</i> of gravity might
+  not by this means be explained, by supposing the <i>Globe</i> of Earth,
+  Water, and Air to be included with a <i>fluid</i>, heterogeneous to all
+  and each of them, so subtil, as not only to be every where
+  <i>interspersed</i> through the <i>Air</i>, (or rather the <i>air</i>
+  through it) but to <i>pervade</i> the bodies of <i>Glass</i>, and even
+  the <i>closest Metals</i>, by which means it may endeavour to
+  <i>detrude</i> all earthly bodies as far from it as it can; and partly
+  thereby, and partly by other of its properties may move them towards the
+  Center of the Earth. Now that there is some such fluid, I could produce
+  many Experiments and Reasons, that do seem to prove it: But because it
+  would ask some time and room to set them down and explain them, and to
+  consider and answer all the Objections (many whereof I foresee) that may
+  be alledged against it; I shall at present proceed to other
+  <i>Queries</i>, contenting my self to have here only given a hint of what
+  I may say more elswhere.</p>
+
+  <p>A Third <i>Query</i> then was, Whether the <i>heterogeneity</i> of the
+  <i>ambient fluid</i> may not be accounted a <i>secondary cause</i> of the
+  <i>roundness</i> or <i>globular form</i> of the <i>greater bodies</i> of
+  the world, such as are those of the <i>Sun</i>, <i>Stars</i>, and
+  <i>Planets</i>, the <i>substance</i> of each of which seems altogether
+  <i>heterogeneous</i> to the <i>circum-ambient fluid æther</i>? And of
+  this I shall say more in the Observation of the Moon.</p>
+
+  <p>A Fourth was, Whether the <i>globular form</i> of the <i>smaller
+  parcels</i> of matter here upon the <i>Earth</i>, as that of
+  <i>Fruits</i>, <i>Pebbles</i>, or <i>Flints</i>, <i>&amp;c.</i> (which
+  seem to have been a <i>Liquor</i> at first) may not be caused by the
+  <i>heterogeneous ambient fluid</i>. For thus we see that melted
+  <i>Glass</i> will be naturally formed into a <i>round Figure</i>; so
+  likewise any small Parcel of any <i>fusible body</i>, if it be perfectly
+  enclosed by the <i>Air</i>, will be driven into a <i>globular</i> Form;
+  and, when cold, will be found a <i>solid Ball</i>. This is plainly enough
+  manifested to us by their way of making <i>shot</i> with the <i>drops of
+  Lead</i>; which being a very pretty curiosity, and known but to a very
+  few, and having the liberty of publishing it granted me, by that
+  <i>Eminent Virtuoso</i> Sir <i>Robert Moray</i>, who brought in this
+  Account of it to the <i>Royal Society</i>, I have here transcribed and
+  inserted.</p>
+
+<h3>To make small shot of different sizes; Communicated by his
+Highness <i>P.R.</i></h3>
+
+  <p><i>Take Lead out of the Pig what quantity you please, melt it down,
+  stir and clear it with an iron Ladle, gathering together the blackish
+  parts that swim at top like scum, and when you see the colour of the
+  clear Lead to be greenish, but no sooner, strew upon it
+  </i>Auripigmentum<i> powdered according to the
+  quantity of Lead, about as much as will lye upon a half Crown piece will
+  serve for eighteen or twenty pound weight of some sorts of Lead; others
+  will require more, or less. After the </i>Auripigmentum<i> is put in,
+  stir the Lead well, and the </i>Auripigmentum<i> will flame: when the
+  flame is over, take out some of the Lead in a Ladle having a lip or notch
+  in the brim for convenient pouring out of the Lead, and being well warmed
+  amongst the melted Lead, and with a stick make some single drops of Lead
+  trickle out of the Ladle into water in a Glass, which if they fall to be
+  round and without tails, there is </i>Auripigmentum<i> enough put in, and
+  the temper of the heat is right, otherwise put in more. Then lay two bars
+  of Iron (or some more proper Iron-tool made on purpose) upon a Pail of
+  water, and place upon them a round Plate of Copper, of the size and
+  figure of an ordinary large Pewter or Silver Trencher, the hollow whereof
+  is to be about three inches over, the bottom lower then the brims about
+  half an inch, pierced with thirty, forty, or more small holes; the
+  smaller the holes are, the smaller the shot will be; and the brim is to
+  be thicker then the bottom, to conserve the heat the better.</i></p>
+
+  <p><i>The bottom of the Trencher being some four inches distant from the
+  water in the Pail, lay upon it some burning Coles, to keep the Lead
+  melted upon it. Then with the hot Ladle take Lead off the Pot where it
+  stands melted, and pour it softly upon the burning Coles over the bottom
+  of the Trencher, and it will immediately run through the holes into the
+  water in small round drops. Thus pour on new Lead still as fast as it
+  runs through the Trencher till all be done; blowing now and then the
+  Coles with hand-Bellows, when the Lead in the Trencher cools so as to
+  stop from running.</i></p>
+
+  <p><i>While one pours on the Lead, another must, with another Ladle,
+  thrusted four or five inches under water in the Pail, catch from time to
+  time some of the shot, as it drops down, to see the size of it, and
+  whether there be any faults in it. The greatest care is to keep the Lead
+  upon the Trencher in the right degree of heat; if it be too cool, it will
+  not run through the Trencher, though it stand melted upon it; and this is
+  to be helped by blowing the Coals a little, or
+  pouring on new Lead that is hotter: but the cooler the Lead, the larger
+  the Shot; and the hotter, the smaller; when it it too hot, the drops will
+  crack and fly; then you must stop pouring on new Lead, and let it cool;
+  and so long as you observe the right temper of the heat, the Lead will
+  constantly drop into very round Shot, without so much as one with a tail
+  in many pounds.</i></p>
+
+  <p><i>When all is done, take your Shot out of the Pail of water, and put
+  it in a Frying-pan over the fire to dry them, which must be done warily,
+  still shaking them that they melt not; and when they are dry you may
+  separate the small from the great, in Pearl Sives made of Copper or
+  Lattin let into one another, into as many sizes at you please. But if you
+  would have your Shot larger then the Trencher makes them, you may do it
+  with a Stick, making them trickle out of the Ladle, as hath been
+  said.</i></p>
+
+  <p><i>If the Trencher be but toucht a very little when the Lead stops
+  from going through it, and be not too cool, it will drop again, but it it
+  better not to touch it at all. At the melting of the Lead take care that
+  there be no kind of Oyl, Grease, or the like, upon the Pots, or Ladles,
+  or Trencher.</i></p>
+
+  <p><i>The Chief cause of this Globular Figure of the Shot, seems to be
+  the </i>Auripigmentum<i>; for, as soon as it is put in among the melted
+  Lead, it loses its shining brightness, contracting instantly a grayish
+  film or skin upon it, when you scum it to make it clean with the Ladle.
+  So that when the Air comes at the falling drop of the melted Lead, that
+  skin constricts them every where equally: but upon what account, and
+  whether this be the true cause, is left to further disquisition.</i></p>
+
+  <p>Much after this same manner, when the Air is exceeding cold through
+  which it passes; do we find the drops of Rain, falling from the Clouds,
+  congealed into round Hail-stones by the freezing Ambient.</p>
+
+  <p>To which may be added this other known Experiment, That if you gently
+  let fall a drop of <i>water</i> upon small <i>sand</i> or <i>dust</i>,
+  you shall find, as it were, an artificial <i>round stone</i> quickly
+  generated. I cannot upon this occasion omit the mentioning of the strange
+  kind of <i>Grain</i>, which I have observed in a <i>stone</i> brought
+  from <i>Kettering</i> in <i>Northamptonshire</i>, and therefore called by
+  Masons <i>Kettering-Stone</i>, of which see the Description.
+  Which brings into my mind what I long since observed in the fiery Sparks
+  that are struck out of a Steel. For having a great desire to see what was
+  left behind, after the Spark was gone out, I purposely struck fire over a
+  very white piece of Paper, and observing diligently where some
+  conspicuous sparks went out, I found a very little black spot no bigger
+  then the point of a Pin, which through a <i>Microscope</i> appeared to be
+  a perfectly round Ball, looking much like a polisht ball of Steel,
+  insomuch that I was able to see the Image of the window reflected from
+  it. I cannot here stay (having done it more fully in another place) to
+  examine the particular Reasons of it, but shall only hint, that I imagine
+  it to be some small parcel of the Steel, which by the violence of the
+  motion of the stroke (most of which seems to be imprest upon those small
+  parcels) is made so glowing hot, that it is melted into a <i>Vitrum</i>,
+  which by the ambient Air is thrust into the form of a Ball.</p>
+
+  <p>A Fifth thing which I thought worth Examination was, Whether the
+  motion of all kind of Springs, might not be reduced to the Principle
+  whereby the included <i>heterogeneous fluid</i> seems to be moved; or to
+  that whereby two Solids, as Marbles, or the like, are thrust and kept
+  together by the <i>ambient fluid</i>.</p>
+
+  <p>A Sixth thing was, Whether the Rising and Ebullition of the Water out
+  of Springs and Fountains (which lie much higher from the Center of the
+  Earth then the Superficies of the Sea, from whence it seems to be
+  derived) may not be explicated by the rising of Water in a smaller Pipe:
+  For the Sea-water being strained through the Pores or Crannies of the
+  Earth, is, as it were, included in little Pipes, where the pressure of
+  the Air has not so great a power to resist its rising: But examining this
+  way, and finding in it several difficulties almost irremovable, I thought
+  upon a way that would much more naturally and conceivably explain it,
+  which was by this following Experiment: I took a Glass-Tube, of the form
+  of that described in the sixth Figure, and chusing two <i>heterogeneous
+  fluids</i>, such as Water and Oyl, I poured in as much Water as filled up
+  the Pipes as high as AB, then putting in some Oyl into the Tube AC, I
+  deprest the superficies A of the Water to F, and B I raised to G, which
+  was not so high perpendicularly as the superficies of the Oyl F, by the
+  space FI, wherefore the proportion of the gravity of these two Liquors
+  was as GH to FE.</p>
+
+  <p>This Experiment I tried with several other Liquors, and particularly
+  with fresh Water and Salt (which I made by dissolving Salt in warm Water)
+  which two though they are nothing heterogeneous, yet before they would
+  perfectly mix one with another, I made trial of the Experiment: Nay,
+  letting the Tube wherein I tried the Experiment remain for many dayes, I
+  observed them not to mix; but the superficies of the fresh was rather
+  more then less elevated above that of the Salt. Now the proportion of the
+  gravity of Sea-water, to that of River-water, according to
+  <i>Stevinus</i> and <i>Varenius</i>, and as I have since found pretty
+  true by making trial my self, is as 46. to 45. that is, 46. Ounces of the
+  salt Water will take up no more room then 45. of the
+  fresh. Or reciprocally 45 pints of salt-water weigh as much as 46 of
+  fresh.</p>
+
+  <p>But I found the proportion of Brine to fresh Water to be near 13 to
+  12: Supposing therefore GHM to represent the Sea, and FI the height of
+  the Mountain above the Superficies of the Sea, FM a Cavern in the Earth,
+  beginning at the bottom of the Sea, and terminated at the top of the
+  Mountain, LM the Sand at the bottom, through which the Water is as it
+  were strained, so as that the fresher parts are only permitted to
+  transude, and the saline kept back; if therefore the proportion of G M to
+  FM be as 45 to 46, then may the Cylinder of Salt-water GM make the
+  Cylinder of Fresh-water to rise as high as E, and to run over at N. I
+  cannot here stand to examine or confute their Opinion, who make the depth
+  of the Sea, below its Superficies, to be no more perpendicularly measured
+  then the height of the Mountains above it: 'Tis enough for me to say,
+  there is no one of those that have asserted it, have experimentally known
+  the perpendicular of either; nor shall I here determine, whether there
+  may not be many other causes of the separation of the fresh water from
+  the salt, as perhaps some parts of the Earth through which it is to pass,
+  may contain a Salt, that mixing and uniting with the Sea-salt, may
+  precipitate it; much after the same manner as the <i>Alkalizate</i> and
+  <i>Acid Salts</i> mix and precipitate each other in the preparation of
+  <i>Tartarum Vitriolatum.</i> I know not also whether the exceeding cold
+  (that must necessarily be) at the bottom of the Water, may not help
+  towards this separation, for we find, that warm Water is able to dissolve
+  and contain more Salt, then the same cold; insomuch that Brines strongly
+  impregnated by heat, if let cool, do suffer much of their Salt to subside
+  and crystallize about the bottom and sides. I know not also whether the
+  exceeding pressure of the parts of the Water one against another, may not
+  keep the Salt from descending to the very bottom, as finding little or no
+  room to insert it self between those parts, protruded so violently
+  together, or else squeeze it upwads into the superiour parts of the Sea,
+  where it may more easily obtain room for it self, amongst the parts of
+  the Water, by reason that there is more heat and less pressure. To this
+  Opinion I was somewhat the more induced by the relations I have met with
+  in <i>Geographical Writers</i>, of drawing fresh Water from the bottom of
+  the Sea, which is salt above. I cannot now stand to examine, whether this
+  natural perpetual motion may not artificially be imitated: Nor can I
+  stand to answer the Objections which may be made against this my
+  Supposition: As, First, How it comes to pass, that there are sometimes
+  salt Springs much higher then the Superficies of the Water? And,
+  Secondly, Why Springs do not run faster and slower, according to the
+  varying height made of the Cylinder of Sea-water, by the ebbing and
+  flowing of the Sea?</p>
+
+  <p>As to the First, In short, I say, the fresh Water may receive again a
+  saline Tincture near the Superficies of the Earth, by passing through
+  some salt <i>Mines</i>, or else many of the saline parts of the Sea may
+  be kept back, though not all.</p>
+
+  <p>And as to the Second, The same <i>Spring</i> may be fed and supplyed
+  by divers <i>Caverns</i>, coming from very far distant parts of the
+  <i>Sea</i>, so as that it may in one place be <i>high</i>, in another
+  <i>low water</i>; and so by that means the <i>Spring</i> may be equally
+  supply'd at all times. Or else the <i>Cavern</i> may be so straight and
+  narrow, that the water not having so ready and free passage through it,
+  cannot upon so short and quick mutations of pressure, be able to produce
+  any sensible effect at such a distance. Besides that, to confirm this
+  <i>hypothesis</i>, there are many <i>Examples</i> found in <i>Natural
+  Historians</i>, of <i>Springs</i> that do ebb and flow like the Sea: As
+  particularly, those recorded by the Learned <i>Camden</i>, and after him
+  by <i>Speed,</i> to be found in this <i>Island</i>: One of which, they
+  relate to be on the Top of a Mountain, by the small Village <i>Kilken</i>
+  in <i>Flintshire</i>, <i>Maris æmulus qui statis temporibus suos evomit
+  &amp; resorbet Aquas</i>; Which at certain times riseth and falleth after
+  the manner of the Sea. A Second in <i>Caermardenshire,</i> near
+  <i>Caermarden</i>, at a place called <i>Cantred Bichan</i>; <i>Qui (ut
+  scribit Giraldus) naturali die bis undis deficiens, &amp; toties
+  exuberans, marinas imitatur instabilitates</i>; That twice in four and
+  twenty hours ebbing and flowing; resembleth the unstable motions of the
+  Sea. The <i>Phænomena</i> of which two may be easily made out, by
+  supposing the <i>Cavern</i>, by which they are fed, to arise from the
+  bottom of the next Sea. A Third, is a Well upon the River <i>Ogmore</i>
+  in <i>Glamorganshire</i>, and near unto <i>Newton</i>, of which
+  <i>Camden</i> relates himself to be certified, by a Letter from a Learned
+  Friend of his that observed it, <i>Fons abest hinc, &amp;c.</i> The
+  Letter is a little too long to be inserted, but the substance is this;
+  That this Well ebbs and flows quite contrary to the flowing and ebbing of
+  the Sea in those parts: for 'tis almost empty at Full Sea, but full at
+  Low water. This may happen from the Channel by which it is supplied,
+  which may come from the bottom of a Sea very remote from those parts, and
+  where the Tides are much differing from those of the approximate shores.
+  A Fourth, lies in <i>Westmorland</i>, near the River <i>Leder</i>; <i>Qui
+  instar Euripi sæpius in die reciprocantibus undis fluit &amp;
+  refluit</i>, which ebbs and flows many times a day. This may proceed from
+  its being supplyed from many Channels, coming from several parts of the
+  Sea, lying sufficiently distant asunder to have the times of High-water
+  differing enough one from the other; so as that whensoever it shall be
+  High water over any of those places, where these Channels begin, it shall
+  likewise be so in the Well; but this is but a supposition.</p>
+
+  <p>A Seventh <i>Query</i> was, Whether the <i>dissolution</i> or mixing
+  of several bodies, whether fluid or solid, with saline or other Liquors,
+  might not partly be attributed to this Principle of the congruity of
+  those bodies and their dissolvents? As of Salt in Water, Metals in
+  several <i>Menstruums</i>, Unctuous Gums in Oyls, the mixing of Wine and
+  Water, <i>&amp;c.</i> And whether <i>precipitation</i> be not partly made
+  from the same Principle of Incongruity? I say <i>partly</i>, because
+  there are in some Dissolutions, some other Causes concurrent.</p>
+
+  <p>I shall lastly make a much more seemingly strange and unlikely
+  <i>Query</i>; and that is, Whether this Principle, well examined and
+  explained, may not be found a <i>co-efficient</i> in the
+  most considerable Operations of Nature? As in those of <i>Heat</i>, and
+  <i>Light</i> consequently of <i>Rarefaction</i> and <i>Condensation</i>,
+  <i>Hardness</i>, and <i>Fluidness</i>, <i>Perspicuity</i> and
+  <i>Opacousness</i>, <i>Refractions</i> and <i>Colours. &amp;c.</i> Nay, I
+  know not whether there may be many things done in Nature, in which this
+  may not (be said to) have a Finger? This I have in some other passages of
+  this Treatise further enquired into and shewn, that as well <i>Light</i>
+  as <i>Heat</i> may be caused by <i>corrosion</i>, which is applicable to
+  <i>congruity</i>, and consequently all the rest will be but
+  <i>subsequents</i>: In the mean time I would not willingly be guilty of
+  that <i>Error</i>, which the thrice Noble and Learned <i>Verulam</i>
+  justly takes notice of, as such, and calls <i>Philosophiæ Genus
+  Empiricum, quod in paucorum Experimentorum Angustiis &amp; Obscuritate
+  fundatum est</i>. For I neither conclude from one single Experiment, nor
+  are the Experiments I make use of all made upon one Subject: Nor wrest I
+  any Experiment to make it <i>quadrare</i> with any preconceiv'd Notion.
+  But on the contrary, I endeavour to be conversant in divers kinds of
+  Experiments, and all and every one of those Trials, I make the Standards
+  or Touchstones, by which I try all my former Notions, whether they hold
+  out in weight, and measure, and touch, <i>&amp;c.</i> For as that Body is
+  no other then a Counterfeit Gold, which wants any one of the Proprieties
+  of Gold, (such as are the Malleableness, Weight, Colour, Fixtness in the
+  Fire, Indissolubleness in <i>Aqua fortis</i>, and the like) though it has
+  all the other; so will all those Notions be found to be false and
+  deceitful, that will not undergo all the Trials and Tests made of them by
+  Experiments. And therefore such as will not come up to the desired
+  <i>Apex</i> of Perfection, I rather wholly reject and take new, then by
+  piecing and patching, endeavour to retain the old, as knowing such things
+  at best to be but lame and imperfect. And this course I learned from
+  Nature; whom we find neglectful of the old Body, and suffering its
+  Decaies and Infirmities to remain without repair, and altogether
+  sollicitous and careful of perpetuating the <i>Species</i> by new
+  <i>Individuals</i>. And it is certainly the most likely way to erect a
+  glorious Structure and Temple to <i>Nature</i>, such as she will be found
+  (by any <i>zealous Votary</i>) to reside in; to begin to build a new upon
+  a sure Foundation of Experiments.</p>
+
+  <p>But to digress no further from the consideration of the
+  <i>Phænomena,</i> more immediately explicable by this Experiment, we
+  shall proceed to shew, That, as to the rising of Water in a
+  <i>Filtre</i>, the reason of it will be manifest to him, that does take
+  notice, that a <i>Filtre</i> is constituted of a great number of small
+  long solid bodies, which lie so close together, that the Air in its
+  getting in between them, doth lose of its pressure that it has against
+  the <i>Fluid</i> without them, by which means the Water or Liquor not
+  finding so strong a resistance between them as is able to
+  counter-ballance the pressure on its superficies without, is raised
+  upward, till it meet with a pressure of the Air which is able to hinder
+  it. And as to the Rising of Oyl, melted Tallow, Spirit of Wine,
+  <i>&amp;c.</i> in the Week of a Candle or Lamp, it is evident, that it
+  differs in nothing from the former, save only in this, that in a
+  <i>Filtre</i> the Liquor descends and runs away by another part; and in
+  the Week the Liquor is dispersed and carried away by the
+  Flame; something there is ascribable to the Heat, for that it may rarifie
+  the more volatil and spirituous parts of those combustible Liquors, and
+  so being made lighter then the Air, it maybe protruded upwards by that
+  more ponderous fluid body in the Form of Vapours; but this can be
+  ascribed to the ascension of but a very little, and most likely of that
+  only which ascends without the Week. As for the Rising of it in a Spunge,
+  Bread, Cotton, <i>&amp;c.</i> above the superficies of the subjacent
+  Liquor, what has been said about the <i>Filtre</i> (if considered) will
+  easily suggest a reason, considering that all these bodies abound with
+  small holes or pores.</p>
+
+  <p>From this same Principle also (<i>viz. the unequal pressure of the Air
+  against the unequal superficies of the water</i>) proceeds the cause of
+  the accession or incursion of any floating body against the sides of the
+  containing Vessel; or the <i>appropinquation</i> of two floating bodies,
+  as <i>Bubbles</i>, <i>Corks</i>, <i>Sticks</i>, <i>Straws</i>,
+  <i>&amp;c.</i> one towards another. As for instance, Take a Glass-jar,
+  such as AB in the seventh <i>Figure</i>, and filling it pretty near the
+  top with water, throw into it a small round piece of Cork, as C, and
+  plunge it all over in water, that it be wet, so as that the water may
+  rise up by the sides of it, then placing it any where upon the
+  superficies, about an inch, or one inch and a quarter from any side, and
+  you shall perceive it by degrees to make <i>perpendicularly</i> toward
+  the nearest part of the side, and the nearer it approaches, the faster to
+  be moved, the reason of which <i>Phænomenon</i> will be found no other
+  then this, that the Air has a greater pressure against the middle of the
+  <i>superficies</i>, then it has against those parts that approach nearer,
+  and are <i>contiguous</i> to the sides. Now that the pressure is greater,
+  may (as I shewed before in the explication of the third <i>Figure</i>) be
+  evinced from the flatting of the water in the middle, which arises from
+  the gravity of the under <i>fluid</i>: for since, as I shewed before, if
+  there were no gravity in the under <i>fluid</i>, or that it were equal to
+  that of the upper, the terminating Surface would be <i>Spherical</i>, and
+  since it is the additional pressure of the gravity of water that makes it
+  so flat, it follows, that the pressure upon the middle must be greater
+  then towards the sides. Hence the Ball having a stronger pressure against
+  that side of it which respects the middle of the <i>superficies</i>, then
+  against that which respects the <i>approximate</i> side, must necessarily
+  move towards that part, from whence it finds least resistance, and so be
+  <i>accelerated</i>, as the resistance decrease. Hence the more the water
+  is raised under that part of its way it is passing above the middle, the
+  faster it is moved: And therefore you will find it to move faster in E
+  then in D, and in D then in C. Neither could I find the floating
+  substance to be moved at all, until it were placed upon some part of the
+  <i>Superficies</i> that was sensibly elevated above the height of the
+  middle part. Now that this may be the true cause, you may try with a
+  blown Bladder, and an exactly round Ball upon a very smooth side of some
+  pliable body, as <i>Horn</i> or <i>Quicksilver.</i> For if the Ball be
+  placed under a part of the Bladder which is upon one side of the middle
+  of its pressure, and you press strongly against the Bladder, you shall
+  find the Ball moved from the middle towards the sides.</p>
+
+  <p>Having therefore shewn the reason of the motion of any float towards
+  the sides, the reason of the incursion of any two floating bodies will
+  easily appear: For the rising of the water against the sides of either of
+  them, is an Argument sufficient, to shew the pressure of the Air to be
+  there less, then it is further from it, where it is not so much elevated;
+  and therefore the reason of the motion of the other toward it, will be
+  the same as towards the side of the Glass, only here from the same
+  reason, they are mutually moved toward each other, whereas the side of
+  the Glass in the former remains fixt. If also you gently fill the Jar so
+  full with water, that the water is <i>protuberant</i> above the sides,
+  the same piece of Cork that before did hasten towards the sides, does now
+  fly from it as fast towards the middle of the Superficies; the reason of
+  which will be found no other then this, that the pressure of the Air is
+  stronger against the sides of the Superficies G and H, then against the
+  middle I; for since, as I shewed before, the Principle of congruity would
+  make the terminating Surface Spherical, and that the flatting of the
+  Surface in the middle is from the abatement of the waters pressure
+  outwards, by the contrary indeavour of its gravity; it follows that the
+  pressure in the middle must be less then on the sides; and therefore the
+  consecution will be the same as in the former. It is very odd to one that
+  considers not the reason of it, to see two floating bodies of wood to
+  approach each other, as though they were indued with some magnetical
+  vigour; which brings into my mind what I formerly tried with a piece of
+  Cork or such like body, which I so ordered, that by putting a little
+  stick into the same water, one part of the said Cork would approach and
+  make toward the stick, whereas another would discede and fly away, nay it
+  would have a kind of verticity, so as that if the <i>Æquator</i> (as I
+  may so speak) of the Cork were placed towards the stick, if let alone, it
+  would instantly turn its appropriate Pole toward it, and then run a-tilt
+  at it: and this was done only by taking a dry Cork, and wetting one side
+  of it with one small stroak; for by this means gently putting it upon the
+  water, it would depress the superficies on every side of it that was dry,
+  and therefore the greatest pressure of the Air, being near those sides,
+  caused it either to chase away, or else to fly off from any other
+  floating body, whereas that side only, against which the water ascended,
+  was thereby able to attract.</p>
+
+  <p>It remains only, that I should determine how high the Water or other
+  Liquor may by this means be raised in a smaller Pipe above the
+  Superficies of that without it, and at what height it may be sustained:
+  But to determine this, will be exceeding difficult, unless I could
+  certainly know how much of the Airs pressure is taken off by the smalness
+  of such and such a Pipe, and whether it may be wholly taken off, that is,
+  whether there can be a hole or pore so small, into which Air could not at
+  all enter, though water might with its whole force, for were there such,
+  'tis manifest, that the water might rise in it to some five or six and
+  thirty English Foot high. I know not whether the capillary Pipes in the
+  bodies of small Trees, which we call their <i>Microscopical pores</i>,
+  may not be such; and whether the congruity of the sides of the Pore may
+  not yet draw the juyce even higher then the Air was
+  able by its bare pressure to raise it: For, Congruity is a principle that
+  not only unites and holds a body joyned to it, but, which is more,
+  attracts and draws a body that is very near it, and holds it above its
+  usual height.</p>
+
+  <p>And this is obvious even in a drop of water suspended under any
+  Similar or Congruous body: For, besides the ambient pressure that helps
+  to keep it sustein'd, there is the Congruity of the bodies that are
+  contiguous. This is yet more evident in Tenacious and Glutinous bodies;
+  such as Gummous Liquors, Syrups, Pitch, and Rosin melted, <i>&amp;c.</i>
+  Tar, Turpentine, Balsom, Bird-lime, <i>&amp;c.</i> for there it is
+  evident, that the Parts of the tenacious body, as I may so call it, do
+  stick and adhere so closely together, that though drawn out into long and
+  very slender Cylinders, yet they will not easily relinquish one another;
+  and this, though the bodies be <i>aliquatenus</i> fluid, and in motion by
+  one another, which, to such as consider a fluid body only as its parts
+  are in a confused irregular motion, without taking in also the congruity
+  of the parts one among another, and incongruity to some other bodies,
+  does appear not a little strange. So that besides the incongruity of the
+  ambient fluid to it, we are to consider also the congruity of the parts
+  of the contein'd fluid one with another.</p>
+
+  <p>And this Congruity (that I may here a little further explain it) is
+  both a Tenaceous and an Attractive power; for the Congruity, in the
+  Vibrative motions, may be the cause of all kind of attraction, not only
+  Electrical, but Magnetical also, and therefore it may be also of Tenacity
+  and Glutinousness. For, from a perfect congruity of the motions of two
+  distant bodies, the intermediate fluid particles are separated and droven
+  away from between them, and thereby those congruous bodies are, by the
+  incompassing mediums, compell'd and forced neerer together; wherefore
+  that attractiveness must needs be stronger, when, by an immediate
+  contact, they are forc'd to be exactly the same: As I shew more at large
+  in my <i>Theory</i> of the <i>Magnet</i>. And this hints to me the reason
+  of the suspension of the <i>Mercury</i> many inches, nay many feet, above
+  the usual station of 30 inches. For the parts of <i>Quick-Silver,</i>
+  being so very similar and congruous to each other, if once united, will
+  not easily suffer a divulsion: And the parts of water, that were any
+  wayes <i>heterogeneous</i>, being by <i>exantlation</i> or rarefaction
+  exhausted, the remaining parts being also very similar, will not easily
+  part neither. And the parts of the Glass being solid, are more
+  difficultly disjoyn'd; and the water, being somewhat similar to both, is,
+  as it were, a medium to unite both the <i>Glass</i> and the
+  <i>Mercury</i> together. So that all three being united, and not very
+  dissimilar, by means of this contact, if care be taken that the Tube in
+  erecting be not shogged, the <i>Quicksilver</i> will remain suspended,
+  notwithstanding its contrary indeavour of Gravity, a great height above
+  its ordinary Station; but if this immediate Contact be removed, either by
+  a meer separation of them one from another by the force of a shog,
+  whereby the other becomes imbodied between them, and licks up from the
+  surface some agil parts, and so hurling them makes them air, or else
+  by some small heterogeneous agil part of the
+  Water, or Air, or Quicksilver, which appears like a bubble, and by its
+  jumbling to and fro there is made way for the <i>heterogeneous Æther</i>
+  to obtrude it self between the Glass and either of the other Fluids, the
+  Gravity of <i>Mercury precipitates</i> it downward with very great
+  violence; and if the Vessel that holds the restagnating <i>Mercury</i> be
+  convenient, the <i>Mercury</i> will for a time <i>vibrate</i> to and fro
+  with very large <i>reciprocations</i>, and at last will remain kept up by
+  the pressure of the external Air at the height of neer thirty inches. And
+  whereas it may be objected, that it cannot be, that the meer imbodying of
+  the <i>Æther</i> between these bodies can be the cause, since the
+  <i>Æther</i> having a free passage alwayes, both through the Pores of the
+  Glass, and through those of the Fluids, there is no reason why it should
+  not make a separation at all times whilst it remains suspended, as when
+  it is violently dis-joyned by a shog. To this I answer, That though the
+  <i>Æther</i> passes between the Particles, that is, through the Pores of
+  bodies, so as that any chasme or separation being made, it has infinite
+  passages to admit its entry into it, yet such is the tenacity or
+  attractive virtue of Congruity, that till it be overcome by the meer
+  strength of Gravity, or by a shog assisting that Conatus of Gravity, or
+  by an agil Particle, that is like a leaver agitated by the <i>Æther</i>;
+  and thereby the parts of the congruous substances are separated so far
+  asunder, that the strength of congruity is so far weakened, as not to be
+  able to reunite them, the parts to be taken hold of being removed out of
+  the attractive Sphere, as I may so speak, of the congruity; such, I say,
+  is the tenacity of congruity, that it retains and holds the almost
+  contiguous Particles of the Fluid, and suffers them not to be separated,
+  till by meer force that attractive or retentive faculty be overcome: But
+  the separation being once made beyond the Sphere of the attractive
+  activity of congruity, that virtue becomes of no effect at all, but the
+  <i>Mercury</i> freely falls downwards till it meet with a resistance from
+  the pressure of the <i>ambient</i> Air, able to resist its gravity, and
+  keep it forced up in the Pipe to the height of about thirty inches.</p>
+
+  <p>Thus have I gently raised a Steel <i>pendulum</i> by a Loadstone to a
+  great Angle, till by the shaking of my hand I have chanced to make a
+  separation between them, which is no sooner made, but as if the Loadstone
+  had retained no attractive virtue, the <i>Pendulum</i> moves freely from
+  it towards the other side. So vast a difference is there between the
+  attractive virtue of the <i>Magnet</i> when it acts upon a contiguous and
+  upon a disjoyned body: and much more must there be between the attractive
+  virtues of congruity upon a contiguous and disjoyned body; and in truth
+  the attractive virtue is so little upon a body disjoyned, that though I
+  have with a <i>Microscope</i> observed very diligently, whether there
+  were any extraordinary <i>protuberance</i> on the side of a drop of water
+  that was exceeding neer to the end of a green stick, but did not touch
+  it, I could not perceive the least; though I found, that as soon as ever
+  it toucht it the whole drop would presently unite it self with it; so
+  that it seems an absolute contact is requisite to the exercising of the
+  tenacious faculty of congruity.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsVII" id="obsVII">VII</a>. <i>Of some </i>Phænomena<i> of Glass drops.</i></h3>
+
+  <p>These <i>Glass Drops</i> are small parcels of coarse green Glass taken
+  out of the Pots that contain the <i>Metal</i> (as they call it) in
+  fusion, upon the end of an Iron Pipe; and being exceeding hot, and
+  thereby of a kind of sluggish fluid Confidence, are suffered to drop from
+  thence into a Bucket of cold Water, and in it to lye till they be grown
+  sensibly cold.</p>
+
+  <p>Some of these I broke in the open air, by snapping off a little of the
+  small stem with my fingers, others by crushing it with a small pair of
+  Plyers; which I had no sooner done, then the whole bulk of the drop flew
+  violently, with a very brisk noise, into multitudes of small pieces, some
+  of which were as small as dust, though in some there were remaining
+  pieces pretty large, without any flaw at all, and others very much
+  flaw'd, which by rubbing between ones fingers was easily reduced to dust;
+  these dispersed every way so violently, that some of them pierced my
+  skin. I could not find either with my naked Eye, or a <i>Microscope</i>,
+  that any of the broken pieces were of a regular figure, nor any one like
+  another, but for the most part those that flaw'd off in large pieces were
+  prettily branched.</p>
+
+  <p>The ends of others of these drops I nipt off whilst all the bodies and
+  ends of them lay buried under the water, which, like the former, flew all
+  to pieces with as brisk a noise, and as strong a motion.</p>
+
+  <p>Others of these I tried to break, by grinding away the blunt end, and
+  though I took a seemingly good one, and had ground away neer two thirds
+  of the Ball, yet would it not fly to pieces, but now and then some small
+  rings of it would snap and fly off, not without a brisk noise and quick
+  motion, leaving the Surface of the drop whence it flew very prettily
+  branched or creased, which was easily discoverable by the
+  <i>Microscope</i>. This drop, after I had thus ground it, without at all
+  impairing the remnant that was not ground away, I caused to fly
+  immediately all into sand upon the nipping off the very tip of its
+  slender end.</p>
+
+  <p>Another of these drops I began to grind away at the smaller end, but
+  had not worn away on the stone above a quarter of an inch before the
+  whole drop flew with a brisk crack into sand or small dust; nor would it
+  have held so long, had there not been a little flaw in the piece that I
+  ground away, as I afterwards found.</p>
+
+  <p>Several others of these drops I covered over with a thin but very tuff
+  skin of <i>Icthyocolla</i>, which being very tough and very transparent,
+  was the most convenient substance for these tryals that I could imagine,
+  having dipt, I say, several of these drops in this transparent Glue
+  whilst hot, and suffering them to hang by a string tied about the end of
+  them till they were cold, and the skin pretty tough; then wrapping all
+  the body of the drop (leaving out only the very tip) in fine
+  supple Kids-leather very closely, I nipped off the small top, and found,
+  as I expected, that notwithstanding this skin of Glue, and the close
+  wrapping up in Leather, upon the breaking of the top, the drop gave a
+  crack like the rest, and gave my hand a pretty brisk impulse: but yet the
+  skin and leather was so strong as to keep the parts from flying out of
+  their former posture; and, the skin being transparent, I found that the
+  drop retained exactly its former figure and polish, but was grown
+  perfectly opacous and all over flaw'd, all those flaws lying in the
+  manner of rings, from the bottom or blunt end, to the very top or small
+  point. And by several examinations with a <i>Microscope</i>, of several
+  thus broken, I found the flaws, both within the body of the drop, and on
+  the outward surface, to lye much in this order.</p>
+
+<span class="sidenote">
+<a href="images/scheme-04.png" target="_blank"><i>Schem.</i> 4.</a><br /><i>Fig.</i> X.
+</span>
+  <p>Let AB in the Figure X of the fourth Scheme represent the drop cased
+  over with <i>Icthyocolla</i> or <i>Isinglass</i>, (by being ordered as is
+  before prescribed) crazed or flawed into pieces, but by the skin or case
+  kept in its former figure, and each of its flawed parts preserved exactly
+  in its due posture; the outward appearance of it somewhat plainly to the
+  naked eye, but much more conspicuous if viewed with a small lens appeared
+  much after this shape. That is, the blunt end B for a pretty breadth,
+  namely, as far as the Ring CCC seemed irregularly flawed with divers
+  clefts, which all seemed to tend towards the Center of it, being, as I
+  afterwards found, and shall anon shew in the description of the figure Y,
+  the Basis, as it were, of a Cone, which was terminated a little above the
+  middle of the drop, all the rest of the Surface from CCC to A was flawed
+  with an infinite number of small and parallel Rings, which as they were
+  for the most part very round, so were they very thick and close together,
+  but were not so exactly flaw'd as to make a perfect Ring, but each
+  circular part was by irregular cracks flawed likewise into multitudes of
+  irregular flakes or tiles; and this order was observed likewise the whole
+  length of the neck.</p>
+
+  <p>Now though I could not so exactly cut this <i>conical Body</i> through
+  the <i>Axis</i>, as is represented by the figure Y; yet by
+  <i>anatomizing</i>, as it were, of several, and taking notice of divers
+  particular circumstances, I was informed, that could I have artificially
+  divided a flaw'd drop through the <i>Axis</i> or <i>Center</i>, I should
+  with a <i>Microscope</i> have found it to appear much of this form, where
+  A signifies the <i>Apex</i>, and B the blunt end, CC the Cone of the
+  Basis, which is terminated at T the top or end of it, which seems to be
+  the very middle of the blunt end in which, not only the conical body of
+  the Basis CC is terminated, but as many of the parts of the drop as reach
+  as high as DD.</p>
+
+  <p>And it seemed to be the head or beginning of a Pith, as it were, or a
+  part of the body which seemed more spungy then the rest, and much more
+  irregularly flawed, which from T ascended by EE, though less visible,
+  into the small neck towards A. The Grain, as it were, of all the flaws,
+  that proceeds from all the outward Surface ADCCDA, was much the same, as
+  is represented by the black strokes that meet in the middle DT, DT, DE,
+  DE, <i>&amp;c.</i></p>
+
+  <p>Nor is this kind of Grain, as I may call it, peculiar to Glass drops
+  thus quenched; for (not to mention <i>Coperas-stones</i>, and divers
+  other <i>Marchasites</i> and <i>Minerals</i>, which I have often taken
+  notice of to be in the very same manner flaked or grained, with a kind of
+  Pith in the middle) I have observed the same in all manner of cast Iron,
+  especially the coarser sort, such as Stoves, and Furnaces, and Backs, and
+  Pots are made of: For upon the breaking of any of those Substances it is
+  obvious to observe, how from the out-sides towards the middle, there is a
+  kind of Radiation or Grain much resembling this of the Glass-drop; but
+  this Grain is most conspicuous in Iron-bullets, if they be broken: the
+  same <i>Phænomena</i> may be produced by casting <i>regulus</i> of
+  <i>Antimony</i> into a Bullet-mold, as also with <i>Glass of
+  Antimony</i>, or with almost any such kind of <i>Vitrified substance</i>,
+  either cast into a cold Mold or poured into Water.</p>
+
+  <p>Others of these Drops I heat red hot in the fire, and then suffered
+  them to cool by degrees. And these I found to have quite lost all their
+  <i>fulminating</i> or flying quality, as also their hard, brittle and
+  springy texture; and to emerge of a much softer temper, and much easier
+  to be broken or snapt with ones finger; but its strong and brittle
+  quality was quite destroyed, and it seemed much of the same consistence
+  with other green Glass well nealed in the Oven.</p>
+
+  <p>The Figure and bigness of these for the most part was the same with
+  that of the Figure Z; that is, all the surface of them was very smooth
+  and polisht, and for the most part round, but very rugged or knobbed
+  about D, and all the length of the stem was here and there pitted or
+  flatted. About D, which is at the upper part of the drop under that side
+  of the stem which is concave, there usually was made some one or more
+  little Hillocks or Prominences. The drop it self, before it be broken,
+  appears very transparent, and towards the middle of it, to be very full
+  of small Bubbles, of some kind of aerial substance, which by the
+  refraction of the outward surface appear much bigger then really they
+  are, and this may be in good part removed, by putting the drop under the
+  surface of clear Water, for by that means most part of the refraction of
+  the convex Surface of the drop is destroyed, and the bubbles will appear
+  much smaller. And this, by the by, minds me of the appearing magnitude of
+  the <i>aperture</i> of the <i>iris</i>, or <i>pupil</i> of the eye, which
+  though it appear, and be therefore judged very large, is yet not above a
+  quarter of the bigness it appears of, by the <i>lenticular</i> refraction
+  of the <i>Cornea</i>.</p>
+
+  <p>The cause of all which <i>Phænomena</i> I imagine to be no other then
+  this, That the Parts of the Glass being by the excessive heat of the fire
+  kept off and separated one from another, and thereby put into a kind of
+  sluggish fluid consistence, are suffered to drop off with that heat or
+  agitation remaining in them, into cold Water; by which means the outsides
+  of the drop are presently cool'd and <i>crusted</i>, and are thereby made
+  of a loose texture, because the parts of it have not time to settle
+  themselves leisurely together, and so to lie very close together: And the
+  innermost parts of the drop, retaining still much of their former heat
+  and agitations, remain of a loose texture also, and,
+  according as the cold strikes inwards from the bottom and sides, are
+  quenched, as it were, and made rigid in that very posture wherein the
+  cold finds them. For the parts of the <i>crust</i> being already
+  hardened, will not suffer the parts to shrink any more from the outward
+  Surface inward; and though it shrink a little by reason of the small
+  parcels of some Aerial substances dispersed through the matter of the
+  Glass, yet that is not neer so much as it appears (as I just now hinted;)
+  nor if it were, would it be sufficient for to consolidate and condense
+  the body of Glass into a <i>tuff</i> and close <i>texture</i>, after it
+  had been so excessively rarified by the heat of the glass-Furnace.</p>
+
+  <p>But that there may be such an expansion of the aerial substance
+  contained in those little <i>blebbs</i> or bubbles in the body of the
+  drop, this following Experiment will make more evident.</p>
+
+  <br clear="all" />
+<hr />
+
+  <p>Take a small Glass-Cane about a foot long, seal up one end of it
+  <i>hermetically</i>, then put in a very small bubble of Glass, almost of
+  the shape of an Essence-viol with the open mouth towards the sealed end,
+  then draw out the other end of the Pipe very small, and fill the whole
+  Cylinder with water, then set this Tube by the Fire till the Water begin
+  to boyl, and the Air in the bubble be in good part rarified and driven
+  out, then by sucking at the smalling Pipe, more of the Air or vapours in
+  the bubble may be suck'd out, so that it may sink to the bottom; when it
+  is sunk to the bottom, in the flame of a Candle, or Lamp, nip up the
+  slender Pipe and let it cool: whereupon it is obvious to observe, first,
+  that the Water by degrees will subside and shrink into much less room:
+  Next, that the Air or vapours in the Glass will expand themselves so, as
+  to buoy up the little Glass: Thirdly, that all about the inside of the
+  Glass-pipe there will appear an infinite number of small bubbles, which
+  as the Water grows colder and colder will swell bigger and bigger, and
+  many of them buoy themselves up and break at the top.</p>
+
+  <p>From this <i>Disceding</i> of the heat in Glass drops, that is, by the
+  quenching or cooling Irradiations propagated from the Surface upwards and
+  inwards, by the lines CT, CT, DT, DE, <i>&amp;c.</i> the bubbles in the
+  drop have room to expand themselves a little, and the parts of the Glass
+  contract themselves; but this operation being too quick for the sluggish
+  parts of the Glass, the contraction is performed very unequally and
+  irregularly, and thereby the Particles of the Glass are bent, some one
+  way, and some another, yet so as that most of them draw towards the Pith
+  or middle TEEE, or rather from that outward: so that they cannot
+  <i>extricate</i> or unbend themselves, till some part of TEEE be broken
+  and loosened, for all the parts about that are placed in the manner of an
+  Arch, and so till their hold at TEEE be loosened they cannot fly asunder,
+  but uphold, and shelter, and fix each other much like the stones in a
+  Vault, where each stone does concurre to the stability of the whole
+  Fabrick, and no one stone can be taken away but the whole Arch falls. And
+  wheresoever any of those radiating wedges DTD, &amp;c. are removed, which
+  are the component parts of this Arch, the whole Fabrick presently falls
+  to pieces; for all the Springs of the several
+  parts are set at liberty, which immediately extricate themselves and fly
+  asunder every way; each part by its spring contributing to the darting of
+  it self and some other contiguous part. But if this drop be heat so hot
+  as that the parts by degrees can unbend themselves, and be settled and
+  annealed in that posture, and be then suffered gently to subside and
+  cool; The parts by this nealing losing their springiness, constitute a
+  drop of a more soft but less brittle texture, and the parts being not at
+  all under a flexure, though any part of the middle or Pith TEEE be
+  broken, yet will not the drop at all fly to pieces as before.</p>
+
+  <p>This Conjecture of mine I shall indeavour to make out by explaining
+  each particular Assertion with <i>analogous</i> Experiments: The
+  Assertions are there.</p>
+
+<blockquote>
+  <p>First, That the parts of the Glass, whilst in a fluid Consistence and
+  hot, are more rarified, or take up more room, then when hard and
+  cold.</p>
+
+  <p>Secondly, That the parts of the drop do suffer a twofold
+  contraction.</p>
+
+  <p>Thirdly, That the dropping or quenching the glowing metal in the Water
+  makes it of a hard, springing, and rarified texture.</p>
+
+  <p>Fourthly, That there is a flexion or force remaining upon the parts of
+  the Glass thus quenched, from which they indeavour to extricate
+  themselves.</p>
+
+  <p>Fifthly, That the Fabrick of the drop, that is able to hinder the
+  parts from extricating themselves, is <i>analogus</i> to that of an
+  Arch.</p>
+
+  <p>Sixthly, That the sudden flying asunder of the parts proceeds from
+  their springiness.</p>
+
+  <p>Seventhly, That a gradual heating and cooling does anneal or reduce
+  the parts of Glass to a texture that is more loose, and easilier to be
+  broken, but not so brittle.</p>
+
+</blockquote>
+
+  <p>That the first of these is true may be gathered from this, That
+  <i>Heat is a property of a body arising from the motion or agitation of
+  its parts</i>; and therefore whatever body is thereby toucht must
+  necessarily receive some part of that motion, whereby its parts will be
+  shaken and agitated, and so by degrees free and extricate themselves from
+  one another, and each part so moved does by that motion <i>exert</i> a
+  <i>conatus</i> of <i>protruding</i> and displacing all the adjacent
+  Particles. Thus Air included in a vessel, by being heated will burst it
+  to pieces. Thus have I broke a Bladder held over the fire in my hand,
+  with such a violence and noise, that it almost made me deaf for the
+  present, and much surpassed the noise of a Musket: The like have I done
+  by throwing into the fire small glass Bubbles hermetically sealed, with a
+  little drop of Water included in them. Thus Water also, or any other
+  Liquor, included in a convenient vessel, by being warmed, manifestly
+  expands it self with a very great violence, so as to break the strongest
+  vessel, if when heated it be narrowly imprisoned in it.
+  This is very manifest by the <i>Sealed Thermometers</i>, which I have, by
+  several tryals, at last brought to a great certainty and tenderness: for
+  I have made some with stems above four foot long, in which the expanding
+  Liquor would so far vary, as to be very neer the very top in the heat of
+  Summer, and prety neer the bottom at the coldest time of the Winter. The
+  Stems I use for them are very thick, straight, and even Pipes of Glass,
+  with a very small <i>perforation</i>, and both the head and body I have
+  made on purpose at the Glass-house, of the same metal whereof the Pipes
+  are drawn: these I can easily in the flame of a Lamp, urged with the
+  blast of a pair of Bellows, seal and close together, so as to remain very
+  firm, close and even; by this means I joyn on the body first, and then
+  fill both it and a part of the stem, proportionate to the length of the
+  stem and the warmth of the season I fill it in with the best rectified
+  <i>Spirit of Wine</i> highly <i>ting'd</i> with the lovely colour of
+  <i>Cocheneel</i>, which I deepen the more by pouring some drops of common
+  <i>Spirit of Urine</i>, which must not be too well rectified, because it
+  will be apt to make the Liquor to curdle and stick in the small
+  perforation of the stem. This Liquor I have upon tryal found the most
+  tender of any spirituous Liquor, and those are much more sensibly
+  affected with the variations of heat and cold then other more flegmatick
+  and ponderous Liquors, and as capable of receiving a deep tincture, and
+  keeping it, as any Liquor whatsoever; and (which makes it yet more
+  acceptable) is not subject to be frozen by any cold yet known. When I
+  have thus filled it, I can very easily in the forementioned flame of a
+  Lamp seal and joyn on the head of it.</p>
+
+  <p>Then, for graduating the stem, I fix that for the beginning of my
+  division where the surface of the liquor in the stem remains when the
+  ball is placed in common distilled water, that is so cold that it just
+  begins to freeze and shoot into flakes; and that mark I fix at a
+  convenient place of the stem, to make it capable of exhibiting very many
+  degrees of cold, below that which is requisite to freeze water: the rest
+  of my divisions, both above and below this (which I mark with a [0] or
+  nought) I place according to the Degrees of <i>Expansion</i>, or
+  <i>Contraction</i> of the Liquor in proportion to the bulk it had when it
+  indur'd the newly mention'd freezing cold. And this may be very easily
+  and accurately enough done by this following way; Prepare a Cylindrical
+  vessel of very thin plate Brass or Silver, ABCD of the figure Z; the
+  Diameter AB of whose cavity let be about two inches, and the depth BC the
+  same; let each end be cover'd with a flat and smooth plate of the same
+  substance, closely soder'd on, and in the midst of the upper cover make a
+  pretty large hole EF, about the bigness of a fifth part of the Diameter
+  of the other; into this fasten very well with cement a straight and even
+  Cylindrical pipe of Glass, EFGH, the Diameter of whose cavity let be
+  exactly one tenth of the Diameter of the greater Cylinder. Let this pipe
+  be mark'd at GH with a Diamant, so that G from E may be distant just two
+  inches, or the same height with that of the cavity of the greater
+  Cylinder, then divide the length EG exactly into 10 parts, so the
+  capacity of the hollow of each of these divisions will be 1/1000 part of
+  the capacity of the greater Cylinder. This vessel
+  being thus prepared, the way of marking and graduating the
+  <i>Thermometers</i> may be very easily thus performed:</p>
+
+  <p>Fill this Cylindrical vessel with the same liquor wherewith the
+  <i>Thermometers</i> are fill'd, then place both it and the
+  <i>Thermometer</i> you are to <i>graduate</i>, in water that is ready to
+  be frozen, and bring the surface of the liquor in the <i>Thermometer</i>
+  to the first marke or [0]; then so proportion the liquor in the
+  Cylindrical vessel, that the surface of it may just be at the lower end
+  of the small glass-Cylinder; then very gently and gradually warm the
+  water in which both the <i>Thermometer</i> and this Cylindrical vessel
+  stand, and as you perceive the ting'd liquor to rise in both stems, with
+  the point of a Diamond give several marks on the stem of the
+  <i>Thermometer</i> at those places, which by comparing the expansion in
+  both Stems, are found to correspond to the divisions of the cylindrical
+  vessel, and having by this means marked some few of these divisions on
+  the Stem, it will be very easie by these to mark all the rest of the
+  Stem, and accordingly to assign to every division a proper character.</p>
+
+  <p>A <i>Thermometer</i>, thus marked and prepared, will be the fittest
+  Instrument to make a Standard of heat and cold that can be imagined. For
+  being sealed up, it is not at all subject to variation or wasting, nor is
+  it liable to be changed by the varying pressure of the Air, which all
+  other kind of <i>Thermometers</i> that are open to the Air are liable to.
+  But to proceed.</p>
+
+  <p>This property of Expansion with Heat, and Contraction with Cold, is
+  not peculiar to Liquors only, but to all kind of solid Bodies also,
+  especially Metals, which will more manifestly appear by this
+  Experiment.</p>
+
+  <p>Take the Barrel of a Stopcock of Brass, and let the Key, which is well
+  fitted to it, be riveted into it, so that it may slip, and be easily
+  turned round, then heat this Cock in the fire, and you will find the Key
+  so swollen, that you will not be able to turn it round in the Barrel; but
+  if it be suffered to cool again, as soon as it is cold it will be as
+  movable, and as easie to be turned as before.</p>
+
+  <p>This Quality is also very observable in <i>Lead</i>, <i>Tin</i>,
+  <i>Silver</i>, <i>Antimony</i>, <i>Pitch</i>, <i>Rosin</i>,
+  <i>Bees-wax</i>, <i>Butter</i>, and the like; all which, if after they be
+  melted you suffer gently to cool, you shall find the parts of the upper
+  Surface to subside and fall inwards, losing that plumpness and smoothness
+  it had whilst in fusion. The like I have also observed in the cooling of
+  <i>Glass of Antimony</i>, which does very neer approach the nature of
+  Glass,</p>
+
+  <p>But because these are all Examples taken from other materials then
+  Glass, and argue only, that possibly there may be the like property also
+  in Glass, not that really there is; we shall by three or four Experiments
+  indeavour to manifest that also.</p>
+
+  <p>And the First is an Observation that is very obvious even in these
+  very drops, to wit, that they are all of them terminated with an unequal
+  or irregular Surface, especially about the smaller part of the drop, and
+  the whole length of the stem; as about D, and from thence to A, the whole
+  Surface, which would have been round if the drop had cool'd leisurely,
+  is, by being quenched hastily, very irregularly flatted and pitted; which
+  I suppose proceeds partly from the Waters
+  unequally cooling and pressing the parts of the drop, and partly from the
+  self-contracting or subsiding quality of the substance of the Glass: For
+  the vehemency of the heat of the drop causes such hidden motions and
+  bubbles in the cold Water, that some parts of the Water bear more
+  forcibly against one part then against another, and consequently do more
+  suddenly cool those parts to which they are contiguous.</p>
+
+  <p>A Second Argument may be drawn from the Experiment of cutting Glasses
+  with a hot Iron. For in that Experiment the top of the Iron heats, and
+  thereby rarifies the parts of the Glass that lie just before the crack,
+  whence each of those agitated parts indeavouring to expand its self and
+  get elbow-room, thrusts off all the rest of the contiguous parts, and
+  consequently promotes the crack that was before begun.</p>
+
+  <p>A Third Argument may be drawn from the way of producing a crack in a
+  sound piece or plate of Glass, which is done two wayes, either First, by
+  suddenly heating a piece of Glass in one place more then in another. And
+  by this means <i>chymists</i> usually cut off the necks of Glass-bodies,
+  by two kinds of Instruments, either by a glowing hot round Iron-Ring,
+  which just incompasses the place that is to be cut, or else by a
+  <i>Sulphur'd</i> Threed, which is often wound about the place where the
+  separation is to be made, and then fired. Or Secondly, A Glass may be
+  cracked by cooling it suddenly in any place with Water, or the like,
+  after it has been all leisurely and gradually heated very hot. Both which
+  <i>Phænomena</i> seem manifestly to proceed from the <i>expansion</i> and
+  contraction of the parts of the Glass, which is also made more probable
+  by this circumstance which I have observed, that a piece of common
+  window-glass being heated in the middle very suddenly with a live Coal or
+  hot Iron, does usually at the first crack fall into pieces, whereas if
+  the Plate has been gradually heated very hot, and a drop of cold Water
+  and the like be put on the middle of it, it only flaws it, but does not
+  break it asunder immediately.</p>
+
+  <p>A Fourth Argument may be drawn from this Experiment; Take a
+  Glass-pipe, and fit into a solid stick of Glass, so as it will but just
+  be moved in it. Then by degrees heat them whilst they are one within
+  another, and they will grow stiffer, but when they are again cold, they
+  will be as easie to be turned as before. This Expansion of Glass is more
+  manifest in this Experiment.</p>
+
+  <p>Take a stick of Glass of a considerable length, and fit it so between
+  the two ends or screws of a Lath, that it may but just easily turn, and
+  that the very ends of it may be just toucht and susteined thereby; then
+  applying the flame of the Candle to the middle of it, and heating it hot,
+  you will presently find the Glass to stick very fast on those points, and
+  not without much difficulty to be convertible on them, before that by
+  removing the flame for a while from it, it be suffered to cool, and when
+  you will find it as easie to be turned round as at the first.</p>
+
+  <p>From all which Experiments it is very evident, that all those Bodies,
+  and particularly Glass, suffers an Expansion by Heat, and that a very
+  considerable one, whilst they are in a state of Fusion.
+  For <i>Fluidity</i>, as I elsewhere mention, <i>being nothing but an
+  effect of very strong and quick shaking motion, whereby the parts are, as
+  it were, loosened from each other, and consequently leave an interjacent
+  space or vacuity</i>; it follows, that all those shaken Particles must
+  necessarily take up much more room then when they were at rest, and lay
+  quietly upon each other. And this is further confirmed by a Pot of
+  <i>boyling Alabaster</i>, which will manifestly rise a sixth or eighth
+  part higher in the Pot, whilst it is boyling, then it will remain at,
+  both before and after it be boyled. The reason of which odd
+  <i>Phænomenon</i> (to hint it here only by the way) is this, that there
+  is in the curious powder of Alabaster, and other calcining Stones, a
+  certain watery substance, which is so fixt and included with the solid
+  Particles, that till the heat be very considerable they will not fly
+  away; but after the heat is increased to such a degree, they break out
+  every way in vapours, and thereby so shake and loosen the small corpusles
+  of the Powder from each other, that they become perfectly of the nature
+  of a fluid body, and one may move a stick to and fro through it, and stir
+  it as easily as water, and the vapours burst and break out in bubbles
+  just as in boyling water, and the like; whereas, both before those watery
+  parts are flying away, and after they are quite gone; that is, before and
+  after it have done boyling, all those effects cease, and a stick is as
+  difficultly moved to and fro in it as in sand, or the like. Which
+  Explication I could easily prove, had I time; but this is not a fit place
+  for it.</p>
+
+  <p>To proceed therefore, I say, that the dropping of this expanded Body
+  into cold Water, does make the parts of the Glass suffer a double
+  contraction: The first is, of those parts which are neer the Surface of
+  the Drop. For Cold, as I said before, contracting Bodies, that is, <i>by
+  the abatement of the agitating faculty the parts falling neerer
+  together</i>; the parts next adjoyning to the Water must needs lose much
+  of their motion, and impart it to the Ambient-water (which the Ebullition
+  and commotion of it manifests) and thereby become a solid and hard crust,
+  whilst the innermost parts remain yet fluid and expanded; whence, as they
+  grow cold also by degrees, their parts must necessarily be left at
+  liberty to be condensed, but because of the hardness of the outward
+  crust, the contraction cannot be admitted that way; but there being many
+  very small, and before inconspicuous, bubbles in the substance of the
+  Glass, upon the subsiding of the parts of the Glass, the agil substance
+  contained in them has liberty of expanding it self a little, and thereby
+  those bubbles grow much bigger, which is the second Contraction. And both
+  these are confirmed from the appearance of the Drop it self: for as for
+  the outward parts, we see, first, that it is irregular and shrunk, as it
+  were, which is caused by the yielding a little of the hardened Skin to a
+  Contraction, after the very outmost Surface is settled; and as for the
+  internal parts, one may with ones naked Eye perceive abundance of very
+  conspicuous bubbles, and with the <i>Microscope</i> many more.</p>
+
+  <p>The Consideration of which Particulars will easily make the Third
+  Position probable, that is, that the parts of the drop will be of a very
+  hard, though of a rarified Texture; for if the outward parts of the Drop,
+  by reason of its hard crust, will indure very little Contraction, and the
+  agil Particles, included in those bubbles, by the losing
+  of their agitation, by the decrease of the Heat, lose also most part of
+  their Spring and Expansive power; it follows (the withdrawing of the heat
+  being very sudden) that the parts must be left in a very loose Texture,
+  and by reason of the implication of the parts one about another, which
+  from their sluggishnes and glutinousness I suppose to be much after the
+  manner of the sticks in a Thorn-bush, or a Lock of Wool; it will follow,
+  I say, that the parts will hold each other very strongly together, and
+  indeavour to draw each other neerer together, and consequently their
+  Texture must be very hard and stiff, but very much rarified.</p>
+
+  <p>And this will make probable my next Position, That <i>the parts of the
+  Glass are under a kind of tension or flexure, out of which they indeavour
+  to extricate and free themselves</i>, and thereby all the parts draw
+  towards the Center or middle, and would, if the outward parts would give
+  way, as they do when the outward parts cool leisurely (as in baking of
+  Glasses) contract the bulk of the drop into a much less compass. For
+  since, as I proved before, the Internal parts of the drop, when fluid,
+  were of a very rarified Texture, and, as it were, tos'd open like a Lock
+  of Wool, and if they were suffered leisurely to cool, would be again
+  prest, as it were, close together: And since that the heat, which kept
+  them bended and open, is removed, and yet the parts not suffered to get
+  as neer together as they naturally would; It follows, that the Particles
+  remain under a kind of <i>tension</i> and <i>flexure</i>, and
+  consequently have an indeavour to free themselves from that
+  <i>bending</i> and <i>distension</i>, which they do, as soon as either
+  the tip be broken, or as soon as by a leisurely heating and cooling, the
+  parts are nealed into another posture.</p>
+
+  <p>And this will make my next Position probable, that <i>the parts of the
+  Glass drops are contignated together in the form of an Arch</i>, cannot
+  any where yield or be drawn inwards, till by the removing of some one
+  part of it (as it happens in the removing one of the stones of an Arch)
+  the whole Fabrick is shatter'd, and falls to pieces, and each of the
+  Springs is left at liberty, suddenly to extricate it self: for since I
+  have made it probable, that the internal parts of the Glass have a
+  contractive power inwards, and the external parts are incapable of such a
+  Contraction, and the figure of it being spherical; it follows, that the
+  superficial parts must bear against each other, and keep one another from
+  being condens'd into a less room, in the same manner as the stones of an
+  Arch conduce to the upholding each other in that Figure. And this is made
+  more probable by another Experiment which was communicated to me by an
+  excellent Person, whose extraordinary Abilities in all kind of Knowledg,
+  especially in that of Natural things, and his generous Disposition in
+  communicating, incouraged me to have recourse to him on many occasions.
+  The Experiment was this: Small Glass-balls (about the bigness of that
+  represented in the <i>Figure &amp;.</i>) would, upon rubbing or
+  scratching the inward Surface, fly all insunder, with a pretty brisk
+  noise; whereas neither before nor after the inner Surface had been thus
+  scratcht, did there appear any flaw or crack. And putting the pieces of
+  one of those broken ones together again, the flaws appeared much after
+  the manner of the black lines on the Figure, <i>&amp;.</i> These Balls
+  were small, but exceeding thick bubbles of Glass, which being crack'd off
+  from the <i>Puntilion</i> whilst very hot, and so suffered to cool
+  without nealing them in the Oven over the Furnace, do
+  thereby (being made of white Glass, which cools much quicker then green
+  Glass, and is thereby made much brittler) acquire a very <i>porous</i>
+  and very brittle <i>texture</i>: so that if with the point of a Needle or
+  Bodkin, the inside of any of them be rubbed prety hard, and then laid on
+  a Table, it will, within a very little while, break into many pieces with
+  a brisk noise, and throw the parts above a span asunder on the Table: Now
+  though the pieces are not so small as those of a <i>fulminating</i> drop,
+  yet they as plainly shew, that the outward parts of the Glass have a
+  great <i>Conatus</i> to fly asunder, were they not held together by the
+  <i>tenacity</i> of the parts of the inward Surface: for we see as soon as
+  those parts are crazed by hard rubbing, and thereby their tenacity
+  spoiled, the springiness of the more outward parts quickly makes a
+  divulsion, and the broken pieces will, if the concave Surface of them be
+  further scratcht with a Diamond, fly again into smaller pieces.</p>
+
+  <p>From which preceding considerations it will follow Sixthly, That the
+  sudden flying asunder of the parts as soon as this Arch is any where
+  disordered or broken, proceeds from the springing of the parts; which,
+  indeavouring to <i>extricate</i> themselves as soon as they get the
+  liberty, they perform it with such a quickness, that they throw one
+  another away with very great violence: for the Particles that compose the
+  Crust have a <i>Conatus</i> to lye further from one another, and
+  therefore as soon as the external parts are loosened they dart themselves
+  outward with great violence, just as so many Springs would do, if they
+  were detained and fastened to the body, as soon as they should be
+  suddenly loosened; and the internal parts drawing inward, they contract
+  so violently; that they rebound back again and fly into multitude of
+  small shivers or sands. Now though they appear not, either to the naked
+  Eye, or the <i>Microscope</i>, yet I am very apt to think there may be
+  abundance of small flaws or cracks, which, by reason the strong
+  reflecting Air is not got between the <i>contiguous</i> parts, appear
+  not. And that this may be so, I argue from this, that I have very often
+  been able to make a crack or flaw, in some convenient pieces of Glass, to
+  appear and disappear at pleasure, according as by pressing together, or
+  pulling asunder the contiguous parts, I excluded or admitted the strong
+  reflecting Air between the parts: And it is very probable, that there may
+  be some Body, that is either very rarified Air, or something
+  <i>analogous</i> to it, which fills the bubbles of these drops; which I
+  argue, first, from the roundness of them, and next, from the vivid
+  reflection of Light which they exhibite: Now though I doubt not, but that
+  the Air in them is very much rarified, yet that there is some in them, to
+  such as well consider this Experiment of the disappearing of a crack upon
+  the <i>extruding</i> of the Air, I suppose it will seem more then
+  probable.</p>
+
+  <p>The Seventh and last therefore that I shall prove, is, <i>That the
+  gradual heating and cooling of these so extended bodies does reduce the
+  parts of the Glass to a looser and softer temper</i>. And this I found by
+  heating them, and keeping them for a prety while very red hot in a fire;
+  for thereby I found them to grow a little lighter, and the small Stems to
+  be very easily broken and snapt any where, without at all making the drop
+  fly; whereas before they were so exceeding hard, that they
+  could not be broken without much difficulty; and upon their breaking the
+  whole drop would fly in pieces with very great violence. The Reason of
+  which last seems to be, that the leisurely heating and cooling of the
+  parts does not only wast some part of the Glass it self, but ranges all
+  the parts into a better order, and gives each Particle an opportunity of
+  <i>relaxing</i> its self, and consequently neither will the parts hold so
+  strongly together as before, nor be so difficult to be broken: The parts
+  now more easily yielding, nor will the other parts fly in pieces, because
+  the parts have no bended Springs. The <i>relaxation</i> also in the
+  temper of hardned Steel, and hammered Metals, by nealing them in the
+  fire, seems to proceed from much the same cause. For both by quenching
+  suddenly such Metals as have <i>vitrifed</i> parts interspers'd, as Steel
+  has, and by hammering of other kinds that do not so much abound with
+  them, as Silver Brass, <i>&amp;c.</i> the parts are put into and detained
+  in a bended posture, which by the agitation of Heat are shaken, and
+  loosened, and suffered to unbend themselves.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsVIII" id="obsVIII">VIII</a>. <i>Of the fiery Sparks struck from a Flint or Steel.</i></h3>
+
+  <p>It is a very common Experiment, by striking with a Flint against a
+  Steel, to make certain fiery and shining Sparks to fly out from between
+  those two compressing Bodies. About eight years since, upon casually
+  reading the Explication of this odd <i>Phænomenon</i>, by the most
+  Ingenious <i>Des Cartes</i>, I had a great desire to be satisfied, what
+  that Substance was that gave such a shining and bright Light: And to that
+  end I spread a sheet of white Paper, and on it, observing the place where
+  several of these Sparks seemed to vanish, I found certain very small,
+  black, but glittering Spots of a movable Substance, each of which
+<span class="sidenote">
+<a href="images/scheme-05.png" target="_blank"><i>Schem.</i> 5.</a><br /><i>Fig.</i> 1.
+</span>
+  examining with my <i>Microscope</i>, I found to be a small round
+  <i>Globule</i>; some of which, as they looked prety small, so did they
+  from their Surface yield a very bright and strong reflection on that side
+  which was next the Light; and each look'd almost like a prety bright
+  Iron-Ball, whose Surface was prety regular, such as is represented by the
+  Figure A. In this I could perceive the Image of the Window prety well, or
+  of a Stick, which I moved up and down between the Light and it. Others I
+  found, which were, as to the bulk of the Ball, prety regularly round, but
+  the Surface of them, as it was not very smooth, but rough, and more
+  irregular, so was the reflection from it more faint and confused. Such
+  were the Surfaces of B. C. D. and E. Some of these I found cleft or
+  cracked, as C, others quite broken in two and hollow, as D. which seemed
+  to be half the hollow shell of a Granado, broken irregularly in pieces.
+  Several others I found of other shapes; but that which is represented by
+  E, I observed to be a very big Spark of fire, which went out upon one
+  side of the Flint that I struck fire withall, to which it
+  stuck by the root F, at the end of which small Stem was fastened-on a
+  <i>Hemisphere</i>, or half a hollow Ball, with the mouth of it open from
+  the stemwards, so that it looked much like a Funnel, or an old fashioned
+  Bowl without a foot. This night, making many tryals and observations of
+  this Experiment, I met, among a multitude of the Globular ones which I
+  had observed, a couple of Instances, which are very remarkable to the
+  confirmation of my <i>Hypothesis</i>.</p>
+
+  <p>And the First was of a pretty big Ball fastened on to the end of a
+  small sliver of Iron, which <i>Compositum</i> seemed to be nothing else
+  but a long thin chip of Iron, one of whose ends was melted into a small
+  round Globul; the other end remaining unmelted and irregular, and
+  perfectly Iron.</p>
+
+  <p>The Second Instance was not less remarkable then the First; for I
+  found, when a Spark went out, nothing but a very small thin long sliver
+  of Iron or Steel, unmelted at either end. So that it seems, that some of
+  these Sparks are the slivers or chips of the Iron <i>vitrified</i>,
+  Others are only the slivers melted into Balls without vitrification, And
+  the third kind are only small slivers of the Iron, made red-hot with the
+  violence of the stroke given on the Steel by the Flint.</p>
+
+  <p>He that shall diligently examine the <i>Phænomena</i> of this
+  Experiment, will, I doubt not, find cause to believe, that the reason I
+  have heretofore given of it, is the true and genuine cause of it, namely,
+  That <i>the Spark, appearing so bright in the falling, is nothing else
+  but a small piece of the Steel or Flint, but most commonly of the Steel,
+  which by the violence of the stroke is at the same time sever'd and heat
+  red-hot, and that sometimes to such a degree, as to make it melt together
+  into a small Globule of Steel; and sometimes also is that heat so very
+  intense, as further to melt it and vitrifie it; but many times the heat
+  is so gentle, as to be able to make the sliver only red hot, which
+  notwithstanding falling upon the tinder</i> (that is only a very curious
+  small Coal made of the small threads of Linnen burnt to coals and char'd)
+  <i>it easily sets it on fire</i>. Nor will any part of this
+  <i>Hypothesis</i> seem strange to him that considers, First, that either
+  hammering, or filing or otherwise violently rubbing of Steel, will
+  presently make it so hot as to be able to burn ones fingers. Next, that
+  the whole force of the stroke is exerted upon that small part where the
+  Flint and Steel first touch: For the Bodies being each of them so very
+  hard, the puls cannot be far communicated, that is, the parts of each can
+  yield but very little, and therefore the violence of the concussion will
+  be <i>exerted</i> on that piece of Steel which is cut off by the Flint.
+  Thirdly, that the filings or small parts of Steel are very apt, as it
+  were, to take fire, and are presently red hot, that is, there seems to be
+  a very <i>combustible sulphureous</i> Body in Iron or Steel, which the
+  Air very readily preys upon, as soon as the body is a little violently
+  heated.</p>
+
+  <p>And this is obvious in the filings of Steel or Iron cast through the
+  flame of a Candle; for even by that sudden <i>transitus</i> of the small
+  chips of Iron, they are heat red hot, and that <i>combustible
+  sulphureous</i> Body is presently prey'd upon and devoured by the
+  <i>aereal</i> incompassing <i>Menstruum</i>, whose office in this
+  Particular I have shewn in the Explication of Charcole.</p>
+
+  <p>And in prosecution of this Experiment, having taken the filings of
+  Iron and Steel, and with the point of a Knife cast them through the flame
+  of a Candle, I observed where some conspicuous shining Particles fell,
+  and looking on them with my <i>Microscope</i>, I found them to be nothing
+  else but such round Globules, as I formerly found the Sparks struck from
+  the Steel by a stroke to be, only a little bigger; and shaking together
+  all the filings that had fallen upon the sheet of Paper underneath and
+  observing them with the <i>Microscope</i>, I found a great number of
+  small Globules, such as the former, though there were also many of the
+  parts that had remained untoucht and rough filings or chips of Iron. So
+  that, it seems, Iron does contain a very <i>combustible sulphureous</i>
+  Body, which is, in all likelihood, one of the causes of this
+  <i>Phænomenon</i>, and which may be perhaps very much concerned in the
+  business of its hardening and tempering: of which somewhat it said in the
+  Description of <i>Muscovy-glass</i>.</p>
+
+  <p>So that, these things considered, we need not trouble our selves to
+  find out what kind of Pores they are, both in the Flint and Steel, that
+  contain the <i>Atoms of fire</i>, nor how those <i>Atoms</i> come to be
+  hindred from running all out, when a dore or passage in their Pores is
+  made by the concussion: nor need we trouble our selves to examine by what
+  <i>Prometheus</i> the Element of Fire comes to be fetcht down from above
+  the Regions of the Air, in what Cells or Boxes it is kept, and what
+  <i>Epimetheus</i> lets it go: Nor to consider what it is that causes so
+  great a conflux of the atomical Particles of Fire, which are said to fly
+  to a flaming Body, like Vultures or Eagles to a putrifying Carcass, and
+  there to make a very great pudder. Since we have nothing more difficult
+  in this <i>Hypothesis</i> to conceive, first, as to the kindling of
+  Tinder, then how a large Iron-bullet, let fall red or glowing hot upon a
+  heap of Small-coal, should set fire to those that are next to it first:
+  Nor secondly, is this last more difficult to be explicated, then that a
+  Body, as Silver for Instance, put into a weak <i>Menstruum</i>, as
+  unrectified <i>Aqua fortis</i> should, when it is put in a great heat, be
+  there dissolved by it, and not before; which <i>Hypothesis</i> is more
+  largely explicated in the Description of Charcoal. To conclude, we see by
+  this Instance, how much Experiments may conduce to the regulating of
+  <i>Philosophical notions</i>. For if the most Acute <i>Des Cartes</i> had
+  applied himself experimentally to have examined what substance it was
+  that caused that shining of the falling Sparks struck from a Flint and a
+  Steel, he would certainly have a little altered his <i>Hypothesis</i>,
+  and we should have found, that his Ingenious Principles would have
+  admitted a very plausible Explication of this <i>Phænomenon</i>; whereas
+  by not examining so far as he might, he has set down an Explication which
+  Experiment do's contradict.</p>
+
+  <p>But before I leave this Description, I must not forget to take notice
+  of the Globular form into which each of these is most curiously formed.
+  And this <i>Phænomenon</i>, as I have elsewhere more largely shewn,
+  proceeds from a propriety which belongs to all kinds of fluid Bodies more
+  or less, and is caused by the Incongruity of the Ambient and included
+  Fluid, which so acts and modulates each other, that they acquire, as neer
+  as is possible, a <i>spherical</i> or
+  <i>globular</i> form, which propriety and several of the <i>Phænomena</i>
+  that proceed from it, I have more fully explicated in the sixth
+  Observation.</p>
+
+  <p>One Experiment, which does very much illustrate my present
+  Explication, and is in it self exceeding pretty, I must not pass by: And
+  that is a way of making small <i>Globules</i> or <i>Balls</i> of Lead, or
+  Tin, as small almost as these of Iron or Steel, and that exceeding easily
+  and quickly, by turning the filings or chips of those Metals also into
+  perfectly round <i>Globules</i>. The way, in short, as I received it from
+  the <i>Learned Physitian Doctor</i> I.G. is this;</p>
+
+  <p>Reduce the Metal you would thus shape, into exceeding fine filings,
+  the finer the filings are, the finer will the Balls be: <i>Stratifie</i>
+  these filings with the fine and well dryed powder of quick Lime in a
+  <i>Crucible</i> proportioned to the quantity you intend to make: When you
+  have thus filled your <i>Crucible</i>, by continual
+  <i>stratifications</i> of the filings and powder, so that, as neer as may
+  be, no one of the filings may touch another, place the <i>Crucible</i> in
+  a <i>gradual fire</i>, and by degrees let it be brought to a heat big
+  enough to make all the filings, that are mixt with the quick Lime, to
+  melt, and no more; for if the fire be too hot, many of these filings will
+  joyn and run together; whereas if the heat be proportioned, upon washing
+  the Lime-dust in fair Water, all those small filings of the Metal will
+  subside to the bottom in a most curious powder, consisting all of exactly
+  round <i>Globules</i>, which, if it be very fine, is very excellent to
+  make Hour-glasses of.</p>
+
+  <p>Now though quick Lime be the powder that this direction makes choice
+  of, yet I doubt not, but that there may be much more convenient ones
+  found out, one of which I have made tryal of, and found very effectual;
+  and were it not for discovering, by the mentioning of it, another Secret,
+  which I am not free to impart, I should have here inserted it.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsIX" id="obsIX">IX</a>. <i>Of the Colours observable in Muscovy Glass, and
+other thin Bodies</i>.</h3>
+
+  <p>Moscovy-glass, or <i>Lapis specularis</i>, is a Body that seems to
+  have as many Curiosities in its Fabrick as any common Mineral I have met
+  with: for first, It is transparent to a great thickness: Next, it is
+  compounded of an infinite number of thin flakes joyned or generated one
+  upon another so close &amp; smooth, as with many hundreds of them to make
+  one smooth and thin Plate of a transparent flexible substance, which with
+  care and diligence may be flit into pieces so exceedingly thin as to be
+  hardly perceivable by the eye, and yet even those, which I have thought
+  the thinnest, I have with a good <i>Microscope</i> found to be made up of
+  many other Plates, yet thinner; and it is probable, that, were our
+  <i>Microscopes</i> much better, we might much further discover
+  its divisibility. Nor are these flakes only regular as to the smoothness
+  of their Surfaces, but thirdly, In many Plates they may be perceived to
+  be terminated naturally with edges of the figure of a <i>Rhomboeid</i>.
+  This Figure is much more conspicuous in our English talk, much whereof is
+  found in the Lead Mines, and is commonly called <i>Spar</i>, and
+  <i>Kauck</i>, which is of the same kind of substance with the
+  <i>Selenitis</i>, but is seldom found in so large flakes as that is, nor
+  is it altogether so tuff, but is much more clear and transparent, and
+  much more curiously shaped, and yet may be cleft and flak'd like the
+  other <i>Selenitis</i>. But fourthly, this stone has a property, which in
+  respect of the <i>Microscope</i>, is more notable, and that is, that it
+  exhibits several appearances of Colours, both to the naked Eye, but much
+  more conspicuously to the <i>Microscope</i>; for the exhibiting of which,
+  I took a piece of <i>Muscovy-glass</i>, and splitting or cleaving it into
+  thin Plates, I found that up and down in several parts of them I could
+  plainly perceive several white specks or flaws, and others diversly
+  coloured with all the Colours of the <i>Rainbow</i>; and with the
+  <i>Microscope</i> I could perceive, that these Colours were ranged in
+  rings that incompassed the white speck or flaw, and were round or
+  irregular, according to the shape of the spot which they terminated; and
+  the position of Colours, in respect of one another, was the very same as
+  in the <i>Rainbow</i>. The consecution of those Colours from the middle
+  of the spot outward being Blew, Purple, Scarlet, Yellow, Green; Blew,
+  Purple, Scarlet, and so onwards, sometimes half a score times repeated,
+  that is, there appeared six, seven, eight, nine or ten several coloured
+  rings or lines, each incircling the other, in the same manner as I have
+  often seen a very <i>vivid Rainbow</i> to have four or five several Rings
+  of Colours, that is, accounting all the Gradations between Red and Blew
+  for one: But the order of the Colours in these Rings was quite contrary
+  to the primary or innermost <i>Rainbow</i>, and the same with those of
+  the secondary or outermost Rainbow; these coloured Lines or
+  <i>Irises</i>, as I may so call them, were some of them much brighter
+  then others, and some of them also very much broader, they being some of
+  them ten, twenty, nay, I believe, neer a hundred times broader then
+  others; and those usually were broadest which were neerest the center or
+  middle of the flaw. And oftentimes I found, that these Colours reacht to
+  the very middle of the flaw, and then there appeared in the middle a very
+  large spot, for the most part, all of one colour, which was very vivid,
+  and all the other Colours incompassing it, gradually ascending, and
+  growing narrower towards the edges, keeping the same order, as in the
+  <i>secundary Rainbow</i>, that is, if the middle were Blew, the next
+  incompassing it would be a Purple, the third a Red, the fourth a Yellow,
+  <i>&amp;c.</i> as above; if the middle were a Red, the next without it
+  would be a Yellow, the third a Green, the fourth a Blew, and so onward.
+  And this order it alwayes kept whatsoever were the middle Colour.</p>
+
+  <p>There was further observable in several other parts of this Body, many
+  Lines or Threads, each of them of some one peculiar Colour, and those so
+  exceedingly bright and vivid, that it afforded a very pleasant object
+  through the <i>Microscope</i>. Some of these
+  <i>threads</i> I have observed also to be pieced or made up of several
+  short lengths of differently coloured <i>ends</i> (as I may so call them)
+  as a line appearing about two inches long through the <i>Microscope</i>,
+  has been compounded of about half an inch of a Peach colour, 1/8 of a
+  lovely Grass-green, 3/4 of an inch more of a bright Scarlet, and the rest
+  of the line of a Watchet blew. Others of them were much otherwise
+  coloured; the variety being almost infinite. Another thing which is very
+  observable, is, that if you find any place where the colours are very
+  broad and conspicuous to the naked eye, you may, by pressing that place
+  with your finger, make the colours change places, and go from one part to
+  another.</p>
+
+  <p>There is one <i>Phænomenon</i> more, which may, if care be used,
+  exhibit to the beholder, as it has divers times to me, an exceeding
+  pleasant, and not less instructive Spectacle; And that is, if curiosity
+  and diligence be used, you may so split this admirable Substance, that
+  you may have pretty large Plates (in companion of those smaller ones
+  which you may observe in the Rings) that are perhaps an 1/8 or a 1/6 part
+  of an inch over, each of them appearing through the <i>Microscope</i>
+  most curiously, intirely, and uniformly adorned with some one vivid
+  colour: this, if examined with the <i>Microscope</i>, may be plainly
+  perceived to be in all parts of it equally thick. Two, three, or more of
+  these lying one upon another, exhibit oftentimes curious compounded
+  colours, which produce such a <i>Compositum</i>, as one would scarce
+  imagine should be the result of such <i>ingredients</i>: As perhaps a
+  <i>faint yellow</i> and a <i>blew</i> may produce a very <i>deep
+  purple</i>. But when anon we come to the more strict examination of these
+  <i>Phænomena</i>, and to inquire into the causes and reasons of these
+  productions, we shall, I hope, make it more conceivable how they are
+  produced, and shew them to be no other then the natural and necessary
+  effects arising from the peculiar union of concurrent causes.</p>
+
+  <p>These <i>Phænomena</i>, being so various, and so truly admirable, it
+  will certainly be very well worth our inquiry, to examine the causes and
+  reasons of them, and to consider, whether from these causes
+  demonstratively evidenced, may not be deduced the true causes of the
+  production of all kind of Colours. And I the rather now do it, instead of
+  an Appendix or Digression to this History, then upon the occasion of
+  examining the Colours in Peacocks, or other Feathers, because this
+  Subject, as it does afford more variety of particular Colours, so does it
+  afford much better wayes of examining each circumstance. And this will be
+  made manifest to him that considers, first, that this laminated body is
+  more simple and regular then the parts of Peacocks feathers, this
+  consisting only of an indefinite number of plain and smooth Plates,
+  heaped up, or <i>incumbent</i> on each other. Next, that the parts of
+  this body are much more manageable, to be divided or joyned, then the
+  parts of a Peacocks feather, or any other substance that I know. And
+  thirdly, because that in this we are able from a colourless body to
+  produce several coloured bodies, affording all the variety of Colours
+  imaginable: And several others, which the subsequent Inquiry will make
+  manifest.</p>
+
+  <p>To begin therefore, it is manifest from several circumstances, that
+  the material cause of the <i>apparition</i> of these several Colours, is
+  some <i>Lamina</i> or Plate of a transparent or pellucid body of a
+  thickness very determinate and proportioned according to the greater or
+  less refractive power of the <i>pellucid</i> body. And that this is so,
+  abundance of Instances and particular Circumstances will make
+  manifest.</p>
+
+  <p>As <i>first</i>, if you take any small piece of the
+  <i>Muscovy-glass</i>, and with a Needle, or some other convenient
+  Instrument, cleave it oftentimes into thinner and thinner <i>Laminæ</i>,
+  you shall find, that till you come to a determinate thinness of them,
+  they shall all appear transparent and colourless, but if you continue to
+  split and divide them further, you shall find at last, that each Plate,
+  after it comes to such a determinate thickness, shall appear most lovely
+  ting'd or imbued with a determinate colour. If <i>further</i>, by any
+  means you so flaw a pretty thick piece, that one part does begin to
+  cleave a little from the other, and between those two there be by any
+  means gotten some pellucid <i>medium</i>, those <i>laminated</i> pellucid
+  bodies that fill that space, shall exhibit several Rainbows or coloured
+  Lines, the colours of which will be disposed and ranged according to the
+  various thicknesses of the several parts of that Plate. That this is so,
+  is yet <i>further</i> confirmed by this Experiment.</p>
+
+  <p>Take two small pieces of ground and polisht Looking-glass-plate, each
+  about the bigness of a shilling, take these two dry, and with your
+  fore-fingers and thumbs press them very hard and close together, and you
+  shall find, that when they approach each other very near, there will
+  appear several <i>Irises</i> or coloured Lines, in the same manner almost
+  as in the <i>Muscovy-glass</i>; and you may very easily change any of the
+  Colours of any part of the interposed body, by pressing the Plates closer
+  and harder together, or leaving them more lax; that is, a part which
+  appeared coloured with a red, may be presently ting'd with a yellow,
+  blew, green, purple, or the like, by altering the appropinquation of the
+  terminating Plates. Now that air is not necessary to be the interposed
+  body, but that any other transparent fluid will do much the same, may be
+  tryed by wetting those approximated Surfaces with Water, or any other
+  transparent Liquor, and proceeding with it in the same manner as you did
+  with the Air; and you will find much the like effect, only with this
+  difference, that those comprest bodies, which differ most, in their
+  refractive quality, from the compressing bodies, exhibit the most strong
+  and vivid tinctures. Nor is it necessary, that this <i>laminated</i> and
+  <i>ting'd</i> body should be of a fluid substance, any other substance,
+  provided it be thin enough and transparent, doing the same thing: this
+  the <i>Laminæ</i> of our <i>Muscovy-glass</i> hint; but it may be
+  confirm'd by multitudes of other Instances.</p>
+
+  <p>And first, we shall find, that even Glass it self may, by the help of
+  a Lamp, be blown thin enough to produce these <i>Phænomena</i> of
+  Colours: which <i>Phænomena</i> accidentally happening, as I have been
+  attempting to frame small Glasses with a Lamp, did not a little surprize
+  me at first, having never heard or seen any thing of it before; though
+  afterwards comparing it with the <i>Phænomena</i>, I had often
+  observed in those Bubbles which Children use to make with Soap-water, I
+  did the less wonder; especially when upon Experiment I found, I was able
+  to produce the same <i>Phænomena</i> in thin Bubbles made with any other
+  transparent Substance. Thus have I produced them with Bubbles of
+  <i>Pitch</i>, <i>Rosin</i>, <i>Colophony</i>, <i>Turpentine</i>,
+  <i>Solutions</i> of several <i>Gums</i>, as <i>Gum-Arabick</i> in water;
+  any <i>glutinous</i> Liquor, as <i>Wort</i>, <i>Wine</i>, <i>Spirit of
+  Wine</i>, <i>Oyl of Turpentine</i>, <i>Glare of Snails,</i> &amp;c.</p>
+
+  <p>It would be needless to enumerate the several Instances, these being
+  enough to shew the generality or universality of this propriety. Only I
+  must not omit, that we have instances also of this kind even in metalline
+  Bodies and animal; for those several Colours which are observed to follow
+  each other upon the polisht surface of hardned Steel, when it is by a
+  sufficient degree of heat gradually tempered or softened, are produced,
+  from nothing else but a certain thin <i>Lamina</i> of a <i>vitrum</i> or
+  <i>vitrified</i> part of the Metal, which by that degree of heat, and the
+  concurring action of the ambient Air, is driven out and fixed on the
+  surface of the Steel.</p>
+
+  <p>And this hints to me a very probable (at least, if not the true) cause
+  of the hardning and tempering of Steel, which has not, I think, been yet
+  given, nor, that I know of been so much as thought of by any. And that is
+  this, that the hardness of it arises from a greater proportion of a
+  vitrified Substance interspersed through the pores of the Steel. And that
+  the tempering or softning of it arises from the proportionate or smaller
+  parcels of it left within those pores. This will seem the more probable,
+  if we consider these Particulars.</p>
+
+  <p>First, That the pure parts of Metals are of themselves very
+  <i>flexible</i> and <i>tuff</i>; that is, will indure bending and
+  hammering, and yet retain their continuity.</p>
+
+  <p>Next, That the Parts of all vitrified Substances, as all kinds of
+  Glass, the <i>Scoria</i> of Metals, <i>&amp;c.</i> are very hard, and
+  also very brittle, being neither <i>flexible</i> nor <i>malleable</i>,
+  but may by hammering or beating be broken into small parts or
+  powders.</p>
+
+  <p>Thirdly, That all Metals (excepting Gold and Silver, which do not so
+  much with the bare fire, unless assisted by other saline Bodies) do more
+  or less <i>vitrifie</i> by the strength of fire, that is, are corroded by
+  a saline Substance, which I elsewhere shew to be the true cause of fire;
+  and are thereby, as by several other <i>Menstruums</i> converted into
+  <i>Scoria</i>; And this is called, <i>calcining</i> of them, by Chimists.
+  Thus Iron and Copper by heating and quenching do turn all of them by
+  degrees into <i>Scoria</i>, which are evidently <i>vitrified</i>
+  Substances, and unite with Glass, and are easily <i>fusible</i>; and when
+  cold, very hard, and very brittle.</p>
+
+  <p>Fourthly, That most kind of <i>Vitrifications</i> or
+  <i>Calcinations</i> are made by Salts, uniting and incorporating with the
+  metalline Particles. Nor do I know any one <i>calcination</i> wherein a
+  <i>Saline</i> body may not, with very great probability, be said to be an
+  agent or coadjutor.</p>
+
+  <p>Fifthly, That Iron is converted into Steel by means of the
+  incorporation of certain salts, with which it is kept a certain time in
+  the fire.</p>
+
+  <p>Sixthly, That any Iron may, in a very little time, be <i>case
+  hardned</i>, as the Trades-men call it, by casing the iron to be hardned
+  with clay, and putting between the clay and iron a good quantity of a
+  mixture of <i>Urine</i>, <i>Soot</i>, <i>Sea-salt</i>, and <i>Horses
+  hoofs</i> (all which contein great quantities of Saline bodies) and then
+  putting the case into a good strong fire, and keeping it in a
+  considerable degree of heat for a good while, and afterwards heating, and
+  quenching or cooling it suddenly in cold water.</p>
+
+  <p>Seventhly, That all kind of vitrify'd substances, by being suddenly
+  cool'd, become very hard and brittle. And thence arises the pretty
+  <i>Phænomena</i> of the Glass Drops, which I have already further
+  explained in its own place.</p>
+
+  <p>Eighthly, That those metals which are not so apt to vitrifie, do not
+  acquire any hardness by quenching in water, as Silver, Gold, &amp;c.</p>
+
+  <p>These considerations premis'd, will, I suppose, make way for the more
+  easie reception of this following Explication of the <i>Phænomena</i> of
+  hardned and temper'd Steel. That Steel is a substance made out of Iron,
+  by means of a certain proportionate <i>Vitrification</i> of several
+  parts, which are so curiously and proportionately mixt with the more
+  tough and unalter'd parts of the Iron, that when by the great heat of the
+  fire this vitrify'd substance is melted, and consequently rarify'd, and
+  thereby the pores of the Iron are more open, if then by means of dipping
+  it in cold water it be suddenly cold, and the parts hardned, that is,
+  stay'd in that same degree of <i>Expansion</i> they were in when hot, the
+  parts become very hard and brittle, and that upon the same account almost
+  as small parcels of glass quenched in water grow brittle, which we have
+  already explicated. If after this the piece of Steel be held in some
+  convenient heat, till by degrees certain colours appear upon the surface
+  of the brightned metal, the very hard and brittle tone of the metal, by
+  degrees relaxes and becomes much more tough and soft; namely, the action
+  of the heat does by degrees loosen the parts of the Steel that were
+  before streached or set <i>atilt</i> as it were, and stayed open by each
+  other, whereby they become relaxed and set at liberty, whence some of the
+  more brittle interjacent parts are thrust out and melted into a thin skin
+  on the surface of the Steel, which from no colour increases to a deep
+  Purple, and so onward by these <i>gradations</i> or consecutions,
+  <i>White, Yellow, Orange, Minium, Scarlet, Purple, Blew, Watchet,</i>
+  &amp;c. and the parts within are more conveniently, and proportionately
+  mixt; and so they gradually subside into a texture which is much better
+  proportion'd and closer joyn'd, whence that rigidnesse of parts ceases,
+  and the parts begin to acquire their former <i>ductilness</i>.</p>
+
+  <p>Now, that 'tis nothing but the vitrify'd metal that sticks upon the
+  surface of the colour'd body, is evident from this, that if by any means
+  it be scraped and rubb'd off, the metal underneath it is white and clear;
+  and if it be kept longer in the fire, so as to increase to a considerable
+  thickness, it may, by blows, be beaten off in flakes. This is further
+  confirm'd by this observable, that that Iron or Steel will keep longer
+  from rusting which is covered with this vitrify'd case: Thus also Lead
+  will, by degrees, be all turn'd into a litharge; for
+  that colour which covers the top being scum'd or shov'd aside, appears to
+  be nothing else but a litharge or vitrify'd Lead.</p>
+
+  <p>This is observable also in some sort, on Brass, Copper, Silver, Gold,
+  Tin, but is most conspicuous in Lead: all those Colours that cover the
+  surface of the Metal being nothing else, but a very thin vitrifi'd part
+  of the heated Metal.</p>
+
+  <p>The other Instance we have, is in Animal bodies, as in Pearls, Mother
+  of Pearl-shels, Oyster-shels, and almost all other kinds of stony shels
+  whatsoever. This have I also sometimes with pleasure observ'd even in
+  Muscles and Tendons. Further, if you take any glutinous substance and run
+  it exceedingly thin upon the surface of a smooth glass or a polisht
+  metaline body, you shall find the like effects produced: and in general,
+  wheresoever you meet with a transparent body thin enough, that is
+  terminated by reflecting bodies of differing refractions from it, there
+  will be a production of these pleasing and lovely colours.</p>
+
+  <p>Nor is it necessary, that the two <i>terminating</i> Bodies should be
+  both of the same kind, as may appear by the <i>vitrified Laminæ</i> on
+  <i>Steel</i>, <i>Lead</i>, and other Metals, one surface of which
+  <i>Laminæ</i> is contiguous to the surface of the Metal, the other to
+  that of the Air.</p>
+
+  <p>Nor is it necessary, that these colour'd <i>Laminæ</i> should be of an
+  even thickness, that is, should have their edges and middles of equal
+  thickness, as in a Looking-glass-plate, which circumstance is only
+  requisite to make the Plate appear all of the same colour; but they may
+  resemble a <i>Lens</i>, that is, have their middles thicker then their
+  edges; or else a <i>double concave</i>, that is, be thinner in the middle
+  then at the edges; in both which cases there will be various coloured
+  rings or lines, with differing consecutions or orders of Colours; the
+  order of the first from the middle outwards being Red, Yellow, Green,
+  Blew, <i>&amp;c.</i> And the latter quite contrary.</p>
+
+  <p>But further, it is altogether necessary, that the Plate, in the places
+  where the Colours appear, should be of a determinate thickness: First, It
+  must not be more then such a thickness, for when the Plate is increased
+  to such a thickness, the Colours cease; and besides, I have seen in a
+  thin piece of <i>Muscovy-glass</i>, where the two ends of two Plates,
+  which appearing both single, exhibited two distinct and differing
+  Colours; but in that place where they were united, and constituted one
+  double Plate (as I may call it) they appeared transparent and colourless.
+  Nor, Secondly, may the Plates be <i>thinner</i> then such a determinate
+  <i>cize</i>; for we alwayes find, that the very outmost Rim of these
+  flaws is terminated in a white and colourless Ring.</p>
+
+  <p>Further, in this Production of Colours there is no need of a
+  determinate Light of such a bigness and no more, nor of a determinate
+  position of that Light, that it should be on this side, and not on that
+  side; nor of a terminating shadow, as in the Prisme, and Rainbow, or
+  Water-ball: for we find, that the Light in the open Air, either in or out
+  of the Sun-beams, and within a Room, either from one or many Windows,
+  produces much the same effect: only where the Light is
+  brightest, there the Colours are most <i>vivid</i>. So does the light of
+  a Candle, collected by a Glass-ball. And further, it is all one whatever
+  side of the coloured Rings be towards the light; for the whole Ring keeps
+  its proper Colours from the middle outwards in the same order as I before
+  related, without varying at all, upon changing the position of the
+  light.</p>
+
+  <p>But above all it is most observable, that here are all kind of Colours
+  generated in a <i>pellucid</i> body, where there is properly no such
+  refraction as <i>Des Cartes</i> supposes his <i>Globules</i> to acquire a
+  <i>vertuity</i> by: For in the plain and even Plates it is manifest, that
+  the second refraction (according to <i>Des Cartes</i> his Principles in
+  the <i>fifth section of the eighth Chapter of his Meteors</i>) does
+  regulate and restore the supposed <i>turbinated Globules</i> unto their
+  former uniform motion. This Experiment therefore will prove such a one as
+  our <i>thrice excellent Verulam</i> calls <i>Experimentum Crucis</i>,
+  serving as a Guide or Land-mark, by which to direct our course in the
+  search after the true cause of Colours. Affording us this particular
+  negative Information, that for the production of Colours there is not
+  necessary either a great refraction, as in the Prisme; nor Secondly, a
+  determination of Light and shadow, such as is both in the Prisme and
+  Glass-ball. Now that we may see likewise what affirmative and positive
+  Instruction it yields, it will be necessary, to examine it a little more
+  particularly and strictly; which that we may the better do, it will be
+  requisite to premise somewhat in general concerning the nature of Light
+  and Refraction.</p>
+
+  <p>And first for Light it seems very manifest, that there is no luminous
+  Body but has the parts of it in motion more or less.</p>
+
+  <p>First, That all kind of <i>fiery burning Bodies</i> have their parts
+  in motion, I think, will be very easily granted me. That the <i>spark</i>
+  struck from a Flint and Steel is in a rapid agitation, I have elsewhere
+  made probable. And that the Parts of <i>rotten Wood</i>, <i>rotten
+  Fish</i> and the like, are also in motion, I think, will as easily be
+  conceded by those, who consider, that those parts never begin to shine
+  till the Bodies be in a state of putrefaction; and that is now generally
+  granted by all, to be caused by the motion of the parts of putrifying
+  bodies. That the <i>Bononian stone</i> shines no longer then it is either
+  warmed by the Sun-beams, or by the flame of a Fire or of a Candle, is the
+  general report of those that write of it, and of others that have seen
+  it. And that heat argues a motion of the internal parts is (as I said
+  before) generally granted.</p>
+
+  <p>But there is one Instance more, which was first shewn to the <i>Royal
+  Society</i> by Mr. <i>Clayton</i> a worthy Member thereof, which does
+  make this Assertion more evident then all the rest: And that is, That a
+  <i>Diamond</i> being <i>rub'd</i>, <i>struck</i> or <i>heated</i> in the
+  dark, shines for a pretty while after, so long as that motion, which is
+  imparted by any of those Agents, remains (in the same manner as a Glass,
+  rubb'd, struck, or (by a means which I shall elsewhere mention) heated,
+  yields a sound which lasts as long as the vibrating motion of that
+  <i>sonorous</i> body) several Experiments made on which Stone, are since
+  published in a Discourse of Colours, by the truly honourable
+  Mr. <i>Boyle</i>. What may be said of those <i>Ignes fatui</i> that
+  appear in the night, I cannot so well affirm, having never had the
+  opportunity to examine them my self, nor to be inform'd by any others
+  that had observ'd them: And the relations of them in Authors are so
+  imperfect, that nothing can be built on them. But I hope I shall be able
+  in another place to make it at least very probable, that there is even in
+  those also a Motion which causes this effect. That the shining of
+  <i>Sea-water</i> proceeds from the same cause, may be argued from this,
+  That it shines not till either it be beaten against a Rock, or be some
+  other wayes broken or agitated by Storms, or Oars, or other
+  <i>percussing</i> bodies. And that the Animal <i>Energyes</i> or
+  Spirituous <i>agil</i> parts are very active in <i>Cats eyes</i> when
+  they shine, seems evident enough, because their eyes never shine but when
+  they look very intensly either to find their prey, or being hunted in a
+  dark room, when they seek after their adversary, or to find a way to
+  escape. And the like may be said of the shining <i>Bellies of
+  Gloworms</i>; since 'tis evident they can at pleasure either increase or
+  extinguish that Radiation.</p>
+
+  <p>It would be somewhat too long a work for this place <i>Zetetically</i>
+  to examine, and positively to prove, what particular kind of motion it is
+  that must be the efficient of Light; for though it be a motion, yet 'tis
+  not every motion that produces it, since we find there are many bodies
+  very violently mov'd, which yet afford not such an effect; and there are
+  other bodies, which to our other senses, seem not mov'd so much, which
+  yet shine. Thus Water and quick-silver, and most other liquors heated,
+  shine not; and several hard bodies, as Iron, Silver, Brass, Copper, Wood,
+  &amp;c. though very often struck with a hammer, shine not presently,
+  though they will all of them grow exceeding hot; whereas rotten Wood,
+  rotten Fish, Sea water, Gloworms, <i>&amp;c.</i> have nothing of tangible
+  heat in them, and yet (where there is no stronger light to affect the
+  Sensory) they shine some of them so Vividly, that one may make a shift to
+  read by them.</p>
+
+  <p>It would be too long, I say, here to insert the discursive progress by
+  which I inquir'd after the proprieties of the motion of Light, and
+  therefore I shall only add the result.</p>
+
+  <p>And, First, I found it ought to be exceeding <i>quick</i>, such as
+  those motions of <i>fermentation</i> and <i>putrefaction</i>, whereby,
+  certainly, the parts are exceeding nimbly and violently mov'd; and that,
+  because we find those motions are able more minutely to shatter and
+  divide the body, then the most violent heats <i>menstruums</i> we yet
+  know. And that fire is nothing else but such a <i>dissolution</i> of the
+  Burning body, made by the most <i>universal menstruum</i> of all
+  <i>sulphureous bodies</i>, namely, the Air, we shall in an other place of
+  this Tractate endeavour to make probable. And that, in all extreamly hot
+  shining bodies, there is a very quick motion that causes Light, as well
+  as a more robust that causes Heat, may be argued from the celerity
+  wherewith the bodyes are dissolv'd.</p>
+
+  <p>Next, it must be a <i>Vibrative motion</i>. And for this the newly
+  mention'd <i>Diamond</i> affords us a good argument; since if the motion
+  of the parts did not return, the Diamond must after many
+  rubbings decay and be wasted: but we have no reason to suspect the
+  latter, especially if we consider the exceeding difficulty that is found
+  in cutting or wearing away a Diamond. And a Circular motion of the parts
+  is much more improbable, since, if that were granted, and they be
+  suppos'd irregular and Angular parts, I see not how the parts of the
+  Diamond should hold so firmly together, or remain in the same sensible
+  dimensions, which yet they do. Next, if they be <i>Globular</i>, and
+  mov'd only with a <i>turbinated</i> motion, I know not any cause that can
+  impress that motion upon the <i>pellucid medium</i>, which yet is done.
+  Thirdly, any other <i>irregular</i> motion of the parts one amongst
+  another, must necessarily make the body of a fluid consistence, from
+  which it is far enough. It must therefore be a <i>Vibrating</i>
+  motion.</p>
+
+  <p>And Thirdly, That it is a very <i>short-vibrating motion</i>, I think
+  the instances drawn from the shining of Diamonds will also make probable.
+  For a Diamond being the hardest body we yet know in the World, and
+  consequently the least apt to yield or bend, must consequently also have
+  its <i>vibrations</i> exceeding short.</p>
+
+  <p>And these, I think, are the three principal proprieties of a motion,
+  requisite to produce the effect call'd Light in the Object.</p>
+
+  <p>The next thing we are to consider, is the way or manner of the
+  <i>trajection</i> of this motion through the interpos'd pellucid body to
+  the eye: And here it will be easily granted,</p>
+
+  <p>First, That it must be a body <i>susceptible</i> and <i>impartible</i>
+  of this motion that will deserve the name of a Transparent. And next,
+  that the parts of such a body must be <i>Homogeneous</i>, or of the same
+  kind. Thirdly, that the constitution and motion of the parts must be
+  such, that the appulse of the luminous body may be communicated or
+  propagated through it to the greatest imaginable distance in the least
+  imaginable time, though I see no reason to affirm, that it must be in an
+  instant: For I know not any one Experiment or observation that does prove
+  it. And, whereas it may be objected, That we see the Sun risen at the
+  very instant when it is above the sensible Horizon, and that we see a
+  Star hidden by the body of the Moon at the same instant, when the Star,
+  the Moon, and our Eye are all in the same line; and the like
+  Observations, or rather suppositions, may be urg'd. I have this to
+  answer, That I can as easily deny as they affirm; for I would fain know
+  by what means any one can be assured any more of the Affirmative, then I
+  of the Negative. If indeed the propagation were very slow, 'tis possible
+  something might be discovered by Eclypses of the Moon; but though we
+  should grant the progress of the light from the Earth to the Moon, and
+  from the Moon back to the Earth again to be full two Minutes in
+  performing, I know not any possible means to discover it; nay, there may
+  be some instances perhaps of Horizontal Eclypses that may seem very much
+  to favour this supposition of the slower progression of Light then most
+  imagine. And the like may be said of the Eclypses of the Sun, &amp;c. But
+  of this only by the by. Fourthly, That the motion is propagated every way
+  through an <i>Homogeneous medium</i> by <i>direct</i> or
+  <i>straight</i> lines extended every way like Rays from the center of a
+  Sphere. Fifthly, in an <i>Homogeneous medium</i> this motion is
+  propagated every way with <i>equal velocity</i>, whence necessarily every
+  <i>pulse</i> or <i>vitration</i> of the luminous body will generate a
+  Sphere, which will continually increase, and grow bigger, just after the
+  same manner (though indefinitely swifter) as the waves or rings on the
+  surface of the water do swell into bigger and bigger circles about a
+  point of it, where, by the sinking of a Stone the motion was begun,
+  whence it necessarily follows, that all the parts of these Spheres
+  undulated through an <i>Homogeneous medium</i> cut the Rays at right
+  angles.</p>
+
+  <p>But because all transparent <i>mediums</i> are not <i>Homogeneous</i>
+  to one another, therefore we will next examine how this pulse or motion
+  will be propagated through differingly transparent <i>mediums</i>. And
+  here, according to the most acute and excellent Philosopher <i>Des
+  Cartes</i>, I suppose the sign of the angle of inclination in the first
+  <i>medium</i> to be to the sign of refraction in the second, As the
+  density of the first, to the density of the second. By density, I mean
+  not the density in respect of gravity (with which the refractions or
+  transparency of <i>mediums</i> hold no proportion) but in respect onely
+  to the <i>trajection</i> of the Rays of light, in which respect they only
+  differ in this; that the one propagates the pulse more easily and weakly,
+  the other more slowly, but more strongly. But as for the pulses
+  themselves, they will by the refraction acquire another propriety, which
+  we shall now endeavour to explicate.</p>
+
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>We will suppose therefore in the first Figure ACFD to be a physical
+  Ray, or ABC and DEF to be two Mathematical Rays, <i>trajected</i> from a
+  very remote point of a luminous body through an <i>Homogeneous</i>
+  transparent <i>medium</i> LLL, and DA, EB, FC, to be small portions of
+  the orbicular impulses which must therefore cut the Rays at right angles;
+  these Rays meeting with the plain surface NO of a <i>medium</i> that
+  yields an easier <i>transitus</i> to the propagation of light, and
+  falling <i>obliquely</i> on it, they will in the <i>medium</i> MMM be
+  refracted towards the perpendicular of the surface. And because this
+  <i>medium</i> is more easily <i>trajected</i> then the former by a third,
+  therefore the point C of the orbicular pulse FC will be mov'd to H four
+  spaces in the same time that F the other end of it is mov'd to G three
+  spaces, therefore the whole refracted pulse GH shall be <i>oblique</i> to
+  the refracted Rays CHK and GI; and the angle GHC shall be an acute, and
+  so much the more acute by how much the greater the refraction be, then
+  which nothing is more evident, for the sign of the inclination is to the
+  sign of refraction as GF to TC the distance between the point C and the
+  perpendicular from G on CK, which being as four to three, HC being longer
+  then GF is longer also then TC, therefore the angle GHC is less than GTC.
+  So that henceforth the parts of the pulses GH and IK are mov'd ascew, or
+  cut the Rays at <i>oblique</i> angles.</p>
+
+  <p>It is not my business in this place to set down the reasons why this
+  or that body should impede the Rays more, others less: as why Water
+  should transmit the Rays more easily, though more weakly than air. Onely
+  thus much in general I shall hint, that I suppose
+  the <i>medium</i> MMM to have less of the transparent undulating subtile
+  matter, and that matter to be less implicated by it, whereas LLL I
+  suppose to contain a greater quantity of the fluid undulating substance,
+  and this to be more implicated with the particles of that
+  <i>medium</i>.</p>
+
+  <p>But to proceed, the same kind of <i>obliquity</i> of the Pulses and
+  Rays will happen also when the refraction is made out of a more easie
+  into a more difficult <i>medi&#363;</i>; as by the calculations of GQ
+  &amp; CSR which are refracted from the perpendicular. In both which
+  calculations 'tis <i>obvious</i> to observe, that always that part of the
+  Ray towards which the refraction is made has the end of the <i>orbicular
+  pulse</i> precedent to that of the other side. And always, the oftner the
+  refraction is made the same way, Or the greater the single refraction is,
+  the more is this unequal progress. So that having found this odd
+  propriety to be an inseparable concomitant of a refracted Ray, not
+  streightned by a contrary refraction, we will next examine the
+  refractions of the Sun-beams, as they are suffer'd onely to pass through
+  a small passage, <i>obliquely</i> out of a more difficult, into a more
+  easie <i>medium</i>.</p>
+
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>Let us suppose therefore ABC in the second Figure to represent a large
+  <i>Chimical Glass-body</i> about two foot long, filled with very fair
+  Water as high as AB, and inclin'd in a convenient posture with B towards
+  the Sun: Let us further suppose the top of it to be cover'd with an
+  <i>opacous</i> body, all but the hole <i>ab</i>, through which the
+  Sun-beams are suffer'd to pass into the Water, and are thereby refracted
+  to <i>cdef</i>, against which part, if a Paper be expanded on the
+  outside, there will appear all the colours of the Rain-bow, that is,
+  there will be generated the two principal colours, <i>Scarlet</i> and
+  <i>Blue</i>, and all the <i>intermediate</i> ones which arise from the
+  composition and dilutings of these two, that is, <i>cd</i> shall exhibit
+  a <i>Scarlet</i>, which toward <i>d</i> is diluted into a <i>Yellow</i>;
+  this is the refraction of the Ray, <i>ik</i>, which comes from the
+  underside of the Sun; and the Ray <i>ef</i> shall appear of a deep
+  <i>Blue</i>, which is gradually towards <i>e</i> diluted into a pale
+  <i>Watchet-blue</i>. Between <i>d</i> and <i>e</i> the two <i>diluted</i>
+  colours. <i>Blue</i> and <i>Yellow</i> are mixt and compounded into a
+  <i>Green</i>; and this I imagine to be the reason why <i>Green</i> is so
+  acceptable a colour to the eye, and that either of the two extremes are,
+  if intense, rather a little offensive, namely, the being plac'd in the
+  middle between the two extremes, and compounded out of both those,
+  <i>diluted</i> also, or somewhat qualifi'd, for the <i>composition</i>,
+  arising from the mixture of the two extremes <i>undiluted</i>, makes a
+  <i>Purple</i>, which though it be a lovely colour, and pretty acceptable
+  to the eye, yet is it nothing comparable to the ravishing pleasure with
+  which a curious and well tempered <i>Green</i> affects the eye. If
+  removing the Paper, the eye be plac'd against <i>cd</i>, it will perceive
+  the lower side of the Sun (or a Candle at night which is much better,
+  because it offends not the eye, and is more easily manageable) to be of a
+  deep <i>Red</i>, and if against <i>ef</i> it will perceive the upper part
+  of the luminous body to be of a deep <i>Blue</i>; and these colours will
+  appear deeper and deeper, according as the Rays from the luminous body
+  fall more <i>obliquely</i> on the surface of the Water, and thereby
+  suffer a greater refraction, and the more
+  distinct, the further <i>cdef</i> is removed from the trajecting
+  hole.</p>
+
+  <p>So that upon the whole, we shall find that the reason of the
+  <i>Phænomena</i> seems to depend upon the <i>obliquity</i> of the
+  <i>orbicular pulse</i>, to the Lines of Radiation, and in particular,
+  that the Ray <i>cd</i> which constitutes the <i>Scarlet</i> has its inner
+  parts, namely those which are next to the middle of the luminous body,
+  precedent to the outermost which are contiguous to the dark and
+  <i>unradiating</i> skie. And that the Ray <i>ef</i> which gives a
+  <i>Blue</i>, has its outward part, namely, that which is contiguous to
+  the dark side precedent to the pulse from the innermost, which borders on
+  the bright <i>area</i> of the luminous body.</p>
+
+  <p>We may observe further, that the cause of the <i>diluting</i> of the
+  colours towards the middle, proceeds partly from the wideness of the hole
+  through which the Rays pass, whereby the Rays from several parts of the
+  luminous body, fall upon many of the same parts between <i>c</i> and
+  <i>f</i> as is more manifest by the Figure: And partly also from the
+  nature of the refraction it self, for the vividness or strength of the
+  two terminating colours, arising chiefly as we have seen, from the very
+  great difference that is betwixt the outsides of those <i>oblique
+  undulations</i> &amp; the dark Rays circumambient, and that disparity
+  betwixt the <i>approximate</i> Rays, decaying gradually: the further
+  inward toward the middle of the luminous body they are remov'd, the more
+  must the colour approach to a white or an undisturbed light.</p>
+
+  <p>Upon the calculation of the refraction and reflection from a Ball of
+  Water or Glass, we have much the same <i>Phænomena</i>, namely, an
+  <i>obliquity</i> of the undulation in the same manner as we have found it
+  here. Which, because it is very much to our present purpose, and affords
+  such an <i>Instancia crucis</i>, as no one that I know has hitherto taken
+  notice of, I shall further examine. For it does very plainly and
+  positively distinguish, and shew, which of the two <i>Hypotheses</i>,
+  either the <i>Cartesian</i> or this is to be followed, by affording a
+  generation of all the colors in the Rainbow, where according to the
+  <i>Cartesian Principles</i> there should be none at all generated. And
+  secondly, by affording an instance that does more closely confine the
+  cause of these <i>Phænomena</i> of colours to this present
+  <i>Hypothesis</i>.</p>
+
+  <p>And first, for the <i>Cartesian</i>, we have this to object against
+  it, That whereas he says (<i>Meteorum Cap. 8. Sect. 5.</i>) <i>Sed
+  judicabam unicam (refractione scilicet) ad minim&#363; requiri, &amp;
+  quidem talem ut ejus effectus aliâ contrariâ (refractione) non
+  destruatur: Nam experientia docet si superficies </i>NM<i> &amp;
+  </i>NP<i> (nempe refringentes) Parallelæ forent, radios tantundem per
+  alteram iterum erectos quantum per unam frangerentur, nullos colores
+  depicturos</i>; This Principle of his holds true indeed in a prisme where
+  the refracting surfaces are plain, but is contradicted by the Ball or
+  Cylinder, whether of Water Or Glass, where the refracting surfaces are
+  Orbicular or Cylindrical. For if we examine the passage of any
+  <i>Globule</i> or Ray of the primary <i>Iris</i>, we shall find it to
+  pass out of the Ball or Cylinder again, with the same inclination and
+  refraction that it enter'd in withall, and that that last refraction by
+  means of the <i>intermediate</i> reflection shall be the same as if
+  without any reflection at all the Ray had been twice refracted by two
+  Parallel surfaces.</p>
+
+  <p>And that this is true, not onely in one, but in every Ray that goes to
+  the constitution of the Primary Iris; nay, in every Ray, that suffers
+  only two refractions, and one reflection, by the surface of the round
+  body, we shall presently see most evident, if we repeat the <i>Cartesian
+  Scheme</i>, mentioned in the tenth <i>Section</i> of the eighth
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 3.
+</span>
+  <i>Chapter</i> of his <i>Meteors</i>, where EFKNP in the third Figure
+  is one of the
+  Rays of the Primary Iris, twice refracted at F and N, and once reflected
+  at K by the surface of the Water-ball. For, first it is evident, that KF
+  and KN are equal, because KN being the reflected part of KF they have
+  both the same inclination on the surface K that is the angles FKT, and
+  NKV made by the two Rays and the Tangent of K are equal, which is evident
+  by the Laws of reflection; whence it will follow also, that KN has the
+  same inclination on the surface N, or the Tangent of it XN that the Ray
+  KF has to the surface F, or the Tangent of it FY, whence it must
+  necessarily follow, that the refractions at F and N are equal, that is,
+  KFE and KNP are equal. Now, that the surface N is by the reflection at K
+  made parallel to the surface at F, is evident from the principles of
+  reflection; for reflection being nothing but an inverting of the Rays, if
+  we re-invert the Ray KNP, and make the same inclinations below the line
+  TKV that it has above, it will be most evident, that KH the inverse of KN
+  will be the continuation of the line FK, and that LHI the inverse of OX
+  is parallel to FY. And HM the inverse of NP is Parallel to EF for the
+  angle KHI is equal to KNO which is equal to KFY, and the angle KHM is
+  equal to KNP which is equal to KFE which was to be prov'd.</p>
+
+  <p>So that according to the above mentioned <i>Cartesian</i> principles
+  there should be generated no colour at all in a Ball of Water or Glass by
+  two refractions and one reflection, which does hold most true indeed, if
+  the surfaces be plain, as may be experimented with any kind of prisme
+  where the two refracting surfaces are equally inclin'd to the reflecting;
+  but in this the <i>Phænomena</i> are quite otherwise.</p>
+
+  <p>The cause therefore of the generation of colour must not be what
+  <i>Des Cartes</i> assigns, namely, a certain <i>rotation</i> of the
+  <i>Globuli ætherei</i>, which are the particles which he supposes to
+  constitute the <i>Pellucid medium</i>, But somewhat else, perhaps what we
+  have lately supposed, and shall by and by further prosecute and
+  explain.</p>
+
+  <p>But, First I shall crave leave to propound some other difficulties of
+  his, notwithstanding exceedingly ingenious <i>Hypothesis</i>, which I
+  plainly confess to me seem such; and those are,</p>
+
+  <p>First, if that light be (as is affirmed, <i>Diopt.</i> cap. 1. §. 8.)
+  not so properly a motion, as an action or propension to motion, I cannot
+  conceive how the eye can come to be sensible of the <i>verticity</i> of a
+  <i>Globule</i>, which is generated in a drop of Rain, perhaps a mile off
+  from it. For that <i>Globule</i> is not carry'd to the eye according to
+  his formerly recited Principle; and if not so, I cannot conceive how it
+  can communicate its <i>rotation</i>, or circular motion to the line of
+  the <i>Globules</i> between the drop and the eye. It cannot be by means
+  of every ones turning the next before him; for if so, then onely all the
+  <i>Globules</i> that are in the odd places must be turned the same
+  way with the first, namely, the 3. 5. 7. 9.
+  11, <i>&amp;c.</i> but all the <i>Globules</i> interposited between them
+  in the even places; namely, the 2. 4. 6. 8. 10. <i>&amp;c.</i> must be
+  the quite contrary, whence, according to the <i>Cartesian Hypothesis</i>,
+  there must be no distinct colour generated, but a confusion. Next, since
+  the <i>Cartesian Globuli</i> are suppos'd (<i>Principiorum Philosoph.</i>
+  Part. 3. §. 86.) to be each of them continually in motion about their
+  centers, I cannot conceive how the eye is able to distinguish this new
+  generated motion from their former inherent one, if I may so call that
+  other wherewith they are mov'd or <i>turbinated</i>, from some other
+  cause than refraction. And thirdly, I cannot conceive how these motions
+  should not happen sometimes to oppose each other, and then, in stead of a
+  <i>rotation</i>, there would be nothing but a direct motion generated,
+  and consequently no colour. And fourthly, I cannot conceive, how by the
+  <i>Cartesian Hypothesis</i> it is possible to give any plausible reason
+  of the nature of the Colours generated in the thin <i>laminæ</i> of these
+  our <i>Microscopical Observations</i>; for in many of these, the
+  refracting and reflecting surfaces are parallel to each other, and
+  consequently no <i>rotation</i> can be generated, nor is there any
+  necessity of a shadow or termination of the bright Rays, such as is
+  suppos'd (<i>Chap.</i> 8. §. 5. <i>Et præterea observavi umbram quoque,
+  aut limitationem luminis requiri:</i> and <i>Chap.</i> 8. §. 9.) to be
+  necessary to the generation of any distinct colours; Besides that, here
+  is oftentimes one colour generated without any of the other appendant
+  ones, which cannot be by the <i>Cartesian Hypothesis</i>.</p>
+
+  <p>There must be therefore some other propriety of refraction that causes
+  colour. And upon the examination of the thing, I cannot conceive any one
+  more general, inseparable, and sufficient, than that which I have before
+  assign'd. That we may therefore see how exactly our <i>Hypothesis</i>
+  agrees also with the <i>Phænomena</i> of the refracting round body,
+  whether <i>Globe</i> or <i>Cylinder</i>, we shall next subjoyn our
+  <i>Calculation</i> or <i>Examen</i> of it.</p>
+
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 3.
+</span>
+  <p>And to this end, we will calculate any two Rays: as for instance;
+  let EF be a
+  Ray cutting the <i>Radius</i> CD (divided into 20. parts) in G 16. parts
+  distant from C, and <i>ef</i> another Ray, which cuts the same
+  <i>Radius</i> in <i>g</i> 17. parts distant, these will be refracted to K
+  and <i>k</i>, and from thence reflected to N and <i>n</i>, and from
+  thence refracted toward P and <i>p</i>; therefore the Arch F<i>f</i> will
+  be 5.<sup>d</sup> 5'. The Arch FK 106.<sup>d</sup> 30'. the Arch
+  <i>fk</i> 101.<sup>d</sup> 2'. The line FG 6000. and <i>fg</i> 5267.
+  therefore <i>hf</i>. 733. therefore F<i>c</i> 980, almost. The line FK
+  16024. and <i>fk</i> 15436. therefore N<i>d</i> 196. and <i>no</i> 147
+  almost, the line Nn 1019 the Arch N<i>n</i> 5.<sup>d</sup> 51'. therefore
+  the Angle N<i>no</i> is 34.<sup>d</sup> 43'. therefore the Angle
+  N<i>on</i> is 139.<sup>d</sup> 56'. which is almost 50.<sup>d</sup> more
+  than a right Angle.</p>
+
+  <p>It is evident therefore by this <i>Hypothesis</i>, that at the same
+  time that <i>ef</i> touches <i>f</i>. EF is arrived at <i>c</i>. And by
+  that time <i>efkn</i> is got to <i>n</i>, EFKN is got to <i>d</i> and
+  when it touches N, the pulse of the other Ray is got to <i>o</i>. and no
+  farther, which is very short of the place it should have arriv'd to, to
+  make the Ray <i>np</i> to cut the <i>orbicular pulse</i> N<i>o</i> at
+  right Angles: therefore the Angle N<i>op</i> is an acute Angle, but the
+  quite contrary of this will happen, if 17. and 18. be
+  calculated in stead of 16. and 17. both which does most exactly agree
+  with the <i>Phænomena</i>: For if the Sun, or a Candle (which is better)
+  be placed about E<i>e</i>, and the eye about P<i>p</i>, the Rays
+  EF<i>ef</i> at 16. and 17. will paint the side of the luminous object
+  toward <i>np</i> <i>Blue</i>, and towards NP <i>Red</i>. But the quite
+  contrary will happen when EF is 17. and <i>ef</i> 18. for then towards NP
+  shall be a <i>Blue</i>, and towards <i>np</i> a <i>Red</i>, exactly
+  according to the calculation. And there appears the <i>Blue</i> of the
+  Rainbow, where the two <i>Blue</i> sides of the two Images unite, and
+  there the <i>Red</i> where the two <i>Red</i> sides unite, that is, where
+  the two Images are just disappearing; which is, when the Rays EF and NP
+  produc'd till they meet, make an Angle of about 41. and an half; the like
+  union is there of the two Images in the Production of the <i>Secundary
+  Iris</i>, and the same causes, as upon calculation may appear; onely with
+  this difference, that it is somewhat more faint, by reason of the
+  duplicate reflection, which does always weaken the impulse the oftner it
+  is repeated.</p>
+
+  <p>Now, though the second refraction made at N<i>n</i> be convenient,
+  that is, do make the Rays glance the more, yet is it not altogether
+  requisite; for it is plain from the calculation, that the pulse <i>dn</i>
+  is sufficiently <i>oblique</i> to the Rays KN and <i>kn</i>, as wel as
+  the pulse <i>fc</i> is <i>oblique</i> to the Rays FK &amp; <i>fk</i>. And
+  therefore if a piece of very fine Paper be held close against N<i>n</i>
+  and the eye look on it either through the Ball as from D, or from the
+  other side, as from B. there shall appear a Rainbow, or colour'd line
+  painted on it with the part toward X appearing <i>Red</i>, towards O,
+  <i>Blue</i>; the same also shall happen, if the Paper be placed about
+  K<i>k</i>, for towards T shall appear a <i>Red</i>, and towards V a
+  <i>Blue</i>, which does exactly agree with this my <i>Hypothesis</i>, as
+  upon the calculation of the progress of the pulse will most easily
+  appear.</p>
+
+  <p>Nor do these two observations of the colours appearing to the eye
+  about <i>p</i> differing from what they appear on the Paper at N
+  contradict each other; but rather confirm and exactly agree with one
+  another, as will be evident to him that examines the reasons set down by
+  the ingenious. <i>Des Cartes</i> in the 12. <i>Sect.</i> of the 8.
+  <i>Chapter of his Meteors</i>, where he gives the true reason why the
+  colours appear of a quite contrary order to the eye, to what they
+  appear'd on the Paper if the eye be plac'd in steed of the Paper: And as
+  in the Prisme, so also in the Water-drop, or Globe the <i>Phænomena</i>,
+  and reason are much the same.</p>
+
+  <p>Having therefore shewn that there is such a propriety in the
+  <i>prisme</i> and water <i>Globule</i> whereby the pulse is made
+  <i>oblique</i> to the progressive, and that so much the more, by how much
+  greater the refraction is, I shall in the next place consider, how this
+  conduces to the production of colours, and what kind of impression it
+  makes upon the bottom of the eye; and to this end it will be requisite to
+  examine this <i>Hypothesis</i> a little more particularly.</p>
+
+  <p>First therefore, if we consider the manner of the progress of the
+  pulse, it will seem rational to conclude, that that part or end of the
+  pulse which precedes the other, must necessarily be somwhat more
+  <i>obtunded</i>, or <i>impeded</i> by the
+  resistance of the transparent <i>medium</i>, than the other part or end
+  of it which is subsequent, whose way is, as it were, prepared by the
+  other; especially if the adjacent <i>medium</i> be not in the same manner
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 4.
+</span>
+  enlightned or agitated. And therefore (in the fourth <i>Figure</i> of the
+  sixth <i>Iconism</i>) the Ray AAAHB will have its side HH more deadned by
+  the resistance of the dark or quiet <i>medium</i> PPP, Whence there will
+  be a kind of deadness superinduc'd on the side HHH, which will
+  continually increase from B, and strike deeper and deeper into the Ray by
+  the line BR; Whence all the parts of the triangle, RBHO will be of a dead
+  <i>Blue</i> colour, and so much the deeper, by how much the nearer they
+  lie to the line BHH, which is most deaded or impeded, and so much the
+  more <i>dilute</i>, by how much the nearer it approaches the line BR.
+  Next on the other side of the Ray AAN, the end A of the pulse AH will be
+  promoted, or made stronger, having its passage already prepar'd as 'twere
+  by the other parts preceding, and so its impression wil be stronger; And
+  because of its <i>obliquity</i> to the Ray, there will be propagated a
+  kind of faint motion into QQ the adjacent dark or quiet <i>medium</i>,
+  which faint motion will spread further and further into QQ as the Ray is
+  propagated further and further from A, namely, as far as the line MA,
+  whence all the triangle MAN will be ting'd with a <i>Red</i>, and that
+  <i>Red</i> will be the deeper the nearer it approaches the line MA, and
+  the <i>paler</i> or <i>yellower</i> the nearer it is the line NA. And if
+  the Ray be continued, so that the lines AN and BR (which are the bounds
+  of the <i>Red</i> and <i>Blue diluted</i>) do meet and cross each other,
+  there will be beyond that intersection generated all kinds of
+  <i>Greens</i>.</p>
+
+  <p>Now, these being the proprieties of every single refracted Ray of
+  light, it will be easie enough to consider what must be the result of
+  very many such Rays collateral: As if we suppose infinite such Rays
+  <i>interjacent</i> between AKSB and ANOB, which arc the terminating: For
+  in this case the Ray AKSB will have its <i>Red</i> triangle intire, as
+  lying next to the dark or quiet <i>medium</i>, but the other side of it
+  BS will have no <i>Blue</i>, because the <i>medium adjacent</i> to it
+  SBO, is mov'd or enlightned, and consequently that light does destroy the
+  colour. So likewise will the Ray ANOB lose its <i>Red</i>, because the
+  <i>adjacent medium</i> is mov'd or enlightned, but the other side of the
+  Ray that is <i>adjacent</i> to the dark, namely, AHO will preserve its
+  <i>Blue</i> entire, and these Rays must be so far produc'd as till AN and
+  BR cut each other, before there will be any <i>Green</i> produc'd. From
+  these Proprieties well consider'd, may be deduc'd the reasons of all the
+  <i>Phænomena</i> of the <i>prisme</i>, and of the <i>Globules</i> or
+  drops of Water which conduce to the production of the Rainbow.</p>
+
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 5.
+</span>
+  <p>Next for the impression they make on the <i>Retina</i>, we will
+  further examine this <i>Hypothesis</i>: Suppose therefore ABCDEF, in the
+  fifth <i>Figure</i>, to represent the Ball of the eye: on the
+  <i>Cornea</i> of which ABC two Rays GACH and KCAI (which are the
+  terminating Rays of a luminous body) falling, are by the refraction
+  thereof collected or <i>converg'd</i> into two points at the bottom of
+  the eye. Now, because these terminating Rays, and all the
+  <i>intermediate</i> ones which come from any part of the luminous body,
+  are suppos'd by some sufficient refraction before they
+  enter the eye, to have their pulses made <i>oblique</i> to their
+  progression, and consequently each Ray to have potentially
+  <i>superinduc'd</i> two proprieties, or colours, viz., a <i>Red</i> on
+  the one side, and a <i>Blue</i> on the other, which notwithstanding are
+  never actually manifest, but when this or that Ray has the one or the
+  other side of it bordering on a dark or unmov'd <i>medium</i>, therefore
+  as soon as these Rays are entred into the eye and so have one side of
+  each of them bordering on a dark part of the humours of the eye, they
+  will each of them actually exhibit some colour; therefore ADC the
+  production of GACH will exhibit a <i>Blue</i>, because the side CD is
+  <i>adjacent</i> to the dark <i>medium</i> CQDC, but nothing of a
+  <i>Red</i>, because its side AD is <i>adjacent</i> to the enlightned
+  <i>medium</i> ADFA: And all the Rays that from the points of the luminous
+  body are collected on the parts of the <i>Retina</i> between D and F
+  shall have their <i>Blue</i> so much the more <i>diluted</i> by how much
+  the farther these points of collection are distant from D towards F; and
+  the Ray AFC the production of KCAI, will exhibit a <i>Red</i>, because
+  the side AF is adjacent to the dark or quiet <i>medium</i> of the eye
+  APFA, but nothing of a <i>Blue</i>, because its side CF is
+  <i>adjacent</i> to the enlightned <i>medium</i> CFDC, and all the Rays
+  from the intermediate parts of the luminous body that are collected
+  between F and D shall have their <i>Red</i> so much the more diluted, by
+  how much the farther they are distant from F towards D.</p>
+
+  <p>Now, because by the refraction in the <i>Cornea</i>, and some other
+  parts of the eye, the sides of each Ray, which before were almost
+  parallel, are made to <i>converge</i> and meet in a point at the bottom
+  of the eye, therefore that side of the <i>pulse</i> which preceded before
+  these refractions, shall first touch the <i>Retina</i>, and the other
+  side last. And therefore according as this or that side, or end of the
+  pulse shall be impeded, accordingly will the <i>impressions</i> on the
+  <i>Retina</i> be varied; therefore by the Ray GACH refracted by the
+  <i>Cornea</i> to D there shall be on that point a stroke or impression
+  confus'd, whose weakest end, namely, that by the line CD shall precede,
+  and the stronger, namely, that by the line AD shall follow. And by the
+  Ray KCAI refracted to F, there shall be on that part a confus'd stroke or
+  impression, whose strongest part, namely, that by the line CF shal
+  precede, and whose weakest or impeded, namely, that by the line AF shall
+  follow, and all the intermediate points between F and D will receive
+  impressions from the <i>converg'd</i> Rays so much the more like the
+  impressions on F and D by how much the nearer they approach that or
+  this.</p>
+
+  <p>From the consideration of the proprieties of which impressions, we may
+  collect these short definitions of Colours: That <i>Blue is an impression
+  on the Retina of an oblique and confus'd pulse of light, whose weakest
+  part precedes, and whose strongest follows.</i> And, that <i>Red is an
+  impression on the Retina of an oblique and confus'd pulse of light, whose
+  strongest part precedes, and whose weakest follows.</i></p>
+
+  <p>Which proprieties, as they have been already manifested, in the Prisme
+  and falling drops of Rain, to be the causes of the colours there
+  generated, may be easily found to be the efficients also of the colours
+  appearing in thin <i>laminated</i> transparent bodies; for the
+  explication of which, all this has been premised.</p>
+
+  <p>And that this is so, a little closer examination of the
+  <i>Phænomena</i> and the <i>Figure</i> of the body, by this
+  <i>Hypothesis</i> will make evident.</p>
+
+  <p>For first (as we have already observed) the <i>laminated</i> body must
+  be of a determinate thickness, that is, it must not be thinner then such
+  a determinate quantity; for I have always observ'd, that neer the edges
+  of those which are exceeding thin, the colours disappear, and the part
+  grows white; nor must it be thicker then another determinate quantity;
+  for I have likewise observ'd, that beyond such a thickness, no colours
+  appear'd, but the Plate looked white, between which two determinate
+  thicknesses were all the colour'd Rings; of which in some substances I
+  have found ten or twelve, in others not half so many, which I suppose
+  depends much upon the transparency of the <i>laminated</i> body. Thus
+  though the consecutions are the same in the scumm or the skin on the top
+  of metals; yet in those consecutions in the same colour is not so often
+  repeated as in the consecutions in thin Glass, or in Sope-water, or any
+  other more transparent and glutinous liquor; for in these I have
+  observ'd, <i>Red, Yellow, Green, Blue, Purple; Red, Yellow, Green, Blue,
+  Purple; Red, Yellow, Green, Blue, Purple; Red, Yellow, &amp;c.</i> to
+  succeed each other, ten or twelve times, but in the other more
+  <i>opacous</i> bodies the consecutions will not be half so many.</p>
+
+  <p>And therefore secondly, the <i>laminated</i> body must be transparent,
+  and this I argue from this, that I have not been able to produce any
+  colour at all with an <i>opacous</i> body, though never so thin. And this
+  I have often try'd, by pressing small <i>Globule</i> of <i>Mercury</i>
+  between two smooth Plates of Glass, whereby I have reduc'd that body to a
+  much greater thinness then was requisite to exhibit the colours with a
+  transparent body.</p>
+
+  <p>Thirdly, there must be a considerable reflecting body adjacent to the
+  under or further side of the <i>lamina</i> or <i>plate</i>: for this I
+  always found, that the greater that reflection was, the more vivid were
+  the appearing colours.</p>
+
+  <p>From which Observations, is most evident, that the reflection from the
+  under or further side of the body is the principal cause of the
+  production of these colours; which, that it is so, and how it conduces to
+  that effect, I shall further explain in the following Figure, which is
+  here described of a very great thickness, as if it had been view'd
+  through the <i>Microscope</i>; and 'tis indeed much thicker than any
+  <i>Microscope</i> (I have yet us'd) has been able to shew me those
+  colour'd plates of Glass, or <i>Muscovie-glass</i>, which I have not
+  without much trouble view'd with it, for though I have endeavoured to
+  magnifie them as much as the Glasses were capable of, yet are they so
+  exceeding thin, that I have not hitherto been able positively to
+  determine their thickness. This Figure therefore I here represent, is
+  wholy <i>Hypothetical</i>.</p>
+
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 6.
+</span>
+  <p>Let ABCDHFE in the sixth Figure be a <i>frustum</i> of
+  <i>Muscovy-glass</i>, thinner toward the end AE, and thicker towards DF.
+  Let us first suppose the Ray <i>aghb</i> coming from the Sun, of some
+  remote luminous object to fall <i>obliquely</i> on the thinner plate BAE,
+  part therefore is reflected back by <i>cghd</i>, the first
+  <i>Superficies</i>; whereby the perpendicular pulse
+  <i>ab</i> is after reflexion propagated by <i>cd</i>, <i>cd</i>, equally
+  remote from each other with <i>ab</i>, <i>ab</i>, so that <i>ag</i> +
+  <i>gc</i>, or <i>bh</i> + <i>hd</i> are either of them equal to
+  <i>aa</i>, as is also <i>cc</i>, but the body BAE being transparent, a
+  part of the light of this Ray is refracted in the surface AB, and
+  propagated by <i>gikh</i> to the surface EF, whence it is reflected and
+  refracted again by the surface AB. So that after two refractions and one
+  reflection, there is propagated a kind of fainter Ray <i>emnf</i>, whose
+  pulse is not only weaker by reason of the two refractions in the surface
+  AB, but by reason of the time spent in passing and repassing between the
+  two surfaces AB and EF, <i>ef</i> which is this fainter or weaker pulse
+  comes behind the pulse <i>cd</i>; so that hereby (the surfaces AB, and EF
+  being so neer together, that the eye cannot <i>discriminate</i> them from
+  one) this confus'd or <i>duplicated</i> pulse, whose strongest part
+  precedes, and whose weakest follows, does produce on the <i>Retina</i>,
+  (or the <i>optick nerve</i> that covers the bottom of the eye) the
+  sensation of a <i>Yellow</i>.</p>
+
+  <p>And secondly, this <i>Yellow</i> will appear so much the deeper, by
+  how much the further back towards the middle between <i>cd</i> and
+  <i>cd</i> the spurious pulse <i>ef</i> is remov'd, as in 2 where the
+  surface BC being further remov'd from EF, the weaker pulse <i>ef</i> will
+  be nearer to the middle, and will make an impression on the eye of a
+  <i>Red</i>.</p>
+
+  <p>But thirdly, if the two reflecting surfaces be yet further remov'd
+  asunder (as in 3 CD and EF are) then will the weaker pulse be so farr
+  behind, that it will be more then half the distance between <i>cd</i> and
+  <i>cd</i>. And in this case it will rather seem to precede the following
+  stronger pulse, then to follow the preceding one, and consequently a
+  <i>Blue</i> will be generated. And when the weaker pulse is just in the
+  middle between two strong ones, then is a deep and lovely <i>Purple</i>
+  generated; but when the weaker pulse <i>ef</i> is very neer to <i>cd</i>,
+  then is there generated a <i>Green</i>, which will be <i>bluer</i>, or
+  <i>yellower</i>, according as the <i>approximate</i> weak pulse does
+  precede or follow the stronger.</p>
+
+  <p>Now fourthly, if the thicker Plate chance to be cleft into two thinner
+  Plates, as CDFE is divided into two Plates by the surface GH then from
+  the composition arising from the three reflections in the surfaces CD,
+  GH, and EF, there will be generated several compounded or mixt colours,
+  which will be very differing, according as the proportion between the
+  thicknesses of those two divided Plates CDHG, and GHFE are varied.</p>
+
+  <p>And <i>fifthly</i>, if these surfaces CD and FE are further remov'd
+  asunder, the weaker pulse will yet lagg behind much further, and not
+  onely be <i>coincident</i> with the second, <i>cd</i>, but lagg behind
+  that also, and that so much the more, by how much the thicker the Plate
+  be; so that by degrees it will be <i>coincident</i> with the third
+  <i>cd</i> backward also, and by degrees, as the Plate grows thicker with
+  a fourth, and so onward to a fifth, sixth, seventh, or eighth; so that if
+  there be a thin transparent body, that from the greatest thinness
+  requisite to produce colours, does, in the manner of a Wedge, by degrees
+  grow to the greatest thickness that a Plate can be of, to exhibit a
+  colour by the reflection of Light from such a body, there
+  shall be generated several consecutions of colours, whose order from the
+  thin end towards the thick, shall be <i>Yellow, Red, Purple, Blue, Green;
+  Yellow, Red, Purple, Blue, Green; Yellow, Red, Purple, Blue, Green;
+  Yellow</i>, &amp;c. and these so often repeated, as the weaker pulse does
+  lose paces with its <i>Primary</i>, or first pulse, and is
+  <i>coincident</i> with a second, third, fourth, fifth, sixth,
+  <i>&amp;c.</i> pulse behind the first. And this, as it is
+  <i>coincident</i>, or follows from the first <i>Hypothesis</i> I took of
+  colours, so upon experiment have I found it in multitudes of instances
+  that seem to prove it. One thing which seems of the greatest concern in
+  this <i>Hypothesis</i>, is to determine the greatest or least thickness
+  requisite for these effects, which, though I have not been wanting in
+  attempting, yet so exceeding thin are these coloured Plates, and so
+  imperfect our <i>Microscope</i>, that I have not been hitherto
+  successfull, though if my endeavours shall answer my expectations, I
+  shall hope to gratifie the curious Reader with some things more remov'd
+  beyond our reach hitherto.</p>
+
+  <p>Thus have I, with as much brevity as I was able, endeavoured to
+  explicate (<i>Hypothetically</i> at least) the causes of the
+  <i>Phænomena</i> I formerly recited, on the consideration of which I have
+  been the more particular.</p>
+
+  <p>First, because I think these I have newly given are capable of
+  explicating all the <i>Phænomena</i> of colours, not onely of those
+  appearing in the <i>Prisme</i>, Water-drop, or Rainbow, and in
+  <i>laminated</i> or plated bodies, but of all that are in the world,
+  whether they be fluid or solid bodies, whether in thick or thin, whether
+  transparent, or seemingly opacous, as I shall in the next Observation
+  further endeavour to shew. And secondly, because this being one of the
+  two ornaments of all bodies discoverable by the sight, whether looked on
+  with, or without a <i>Microscope</i>, it seem'd to deserve (somewhere in
+  this Tract, which contains a description of the Figure and Colour of some
+  minute bodies) to be somewhat the more intimately enquir'd into.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsX" id="obsX">X</a>. <i>Of </i>Metalline<i>, and other real Colours.</i></h3>
+
+  <p>Having in the former Discourse, from the Fundamental cause of Colour,
+  made it probable, that there are but two Colours, and shewn, that the
+  <i>Phantasm</i> of Colour is caus'd by the sensation of the
+  <i>oblique</i> or uneven pulse of Light which is capable of no more
+  varieties than two that arise from the two sides of the <i>oblique</i>
+  pulse, though each of those be capable of infinite gradations or degrees
+  (each of them beginning from <i>White</i>, and ending the one in the
+  deepest <i>Scarlet</i> or <i>Yellow</i>, the other in the deepest
+  <i>Blue</i>) I shall in this <i>Section</i> set down some Observations
+  which I have made of other colours, such as <i>Metalline</i> powders
+  tinging or colour'd bodies and several kinds of tinctures or ting'd
+  liquors, all which, together with those I treated of in the former
+  Observation will, I suppose, comprise the several subjects in which
+  colour is observ'd to be inherent, and the several manners by which it
+  <i>inheres</i>, or is apparent in them. And here I shall
+  endeavour to shew by what composition all kind of compound colours are
+  made, and how there is no colour in the world but may be made from the
+  various degrees of these two colours, together with the intermixtures of
+  <i>Black</i> and <i>White</i>.</p>
+
+  <p>And this being so, as I shall anon shew, it seems an evident argument
+  to me, that all colours whatsoever, whether in fluid or solid, whether in
+  very transparent or seemingly <i>opacous</i>, have the same efficient
+  cause, to wit, some kind of <i>refraction</i> whereby the Rays that
+  proceed from such bodies, have their pulse <i>obliquated</i> or confus'd
+  in the manner I explicated in the former <i>Section</i>; that is, a
+  <i>Red</i> is caus'd by a duplicated or confus'd pulse, whose strongest
+  pulse precedes, and a weaker follows: and a <i>Blue</i> is caus'd by a
+  confus'd pulse, where the weaker pulse precedes, and the stronger
+  follows. And according as these are, more or less, or variously mixt and
+  compounded, so are the <i>sensations</i>, and consequently the
+  <i>phantasms</i> of colours <i>diversified</i>.</p>
+
+  <p>To proceed therefore; I suppose, that all transparent colour'd bodies,
+  whether fluid or solid, do consist at least of two parts, or two kinds of
+  substances, the one of a substance of a somewhat differing
+  <i>refraction</i> from the other. That one of these substances which may
+  be call'd the <i>tinging</i> substance, does consist of distinct parts,
+  or particles of a determinate bigness which are <i>disseminated</i>, or
+  dispers'd all over the other: That these particles, if the body be
+  equally and uniformly colour'd, are evenly rang'd and dispers'd over the
+  other contiguous body; That where the body is deepest ting'd, there these
+  particles are rang'd thickest, and where 'tis but faintly ting'd, they
+  are rang'd much thinner, but uniformly. That by the mixture of another
+  body that unites with either of these, which has a differing refraction
+  from either of the other, quite differing effects will be produc'd, that
+  is, the <i>consecutions</i> of the confus'd pulses will be much of
+  another kind, and consequently produce other <i>sensations</i> and
+  <i>phantasms</i> of colours, and from a <i>Red</i> may turn to a
+  <i>Blue</i>, or from a <i>Blue</i> to a <i>Red</i>, &amp;c.</p>
+
+  <p>Now, that this may be the better understood, I shall endeavour to
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 7.
+</span>
+  explain my meaning a little more sensible by a <i>Scheme</i>: Suppose we
+  therefore in the seventh <i>Figure</i> of the sixth <i>Scheme</i>, that
+  ABCD represents a Vessel holding a ting'd liquor, let IIIII, &amp;c. be
+  the clear liquor, and let the tinging body that is mixt with it be EE,
+  <i>&amp;c.</i> FF, <i>&amp;c.</i> GG, <i>&amp;c.</i> HH, <i>&amp;c.</i>
+  whose particles (whether round, or some other determinate Figure is
+  little to our purpose) are first of a determinate and equal bulk. Next,
+  they are rang'd into the form of <i>Quincunx</i>, or
+  <i>Equilaterotriangular</i> order, which that probably they are so, and
+  why they are so, I shall elsewhere endeavour to shew. Thirdly, they are
+  of such a nature, as does either more easily or more difficultly transmit
+  the Rays of light then the liquor; if more easily, a <i>Blue</i> is
+  generated, and if more difficultly, a <i>Red</i> or <i>Scarlet</i>.</p>
+
+  <p>And first, let us suppose the tinging particles to be of a substance
+  that does more <i>impede</i> the Rays of light, we shall find that the
+  pulse or wave of light mov'd from AD to BC, will proceed on, through the
+  containing <i>medium</i> by the pulses or waves KK, LL, MM, NN, OO; but
+  because several of these Rays that go to the
+  constitution of these pulses will be slugged or stopped by the tinging
+  particles E, F, G, H; therefore there shall be <i>secundary</i> and weak
+  pulse that shall follow the Ray, namely PP which will be the weaker:
+  first, because it has suffer'd many refractions in the impeding body;
+  next, for that the Rays will be a little dispers'd or confus'd by reason
+  of the refraction in each of the particles, whether <i>round</i> or
+  <i>angular</i>; and this will be more evident, if we a little more
+  closely examine any one particular tinging <i>Globule</i>.</p>
+
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 8.
+</span>
+  <p>Suppose we therefore AB in the eighth <i>Figure</i> of the sixth
+  <i>Scheme</i>, to represent a tinging <i>Globule</i> or particle which
+  has a greater refraction than the liquor in which it is contain'd: Let CD
+  be a part of the pulse of light which is <i>propagated</i> through the
+  containing <i>medium</i>; this pulse will be a little stopt or impeded by
+  the <i>Globule</i>, and so by that time the pulse is past to EF that part
+  of it which has been impeded by passing through the <i>Globule</i>, will
+  get but to LM, and so that pulse which has been <i>propagated</i> through
+  the <i>Globule</i>, to wit, LM, NO, PQ, will always come behind the
+  pulses EF, GH, IK, <i>&amp;c.</i></p>
+
+  <p>Next, by reason of the greater impediment in AB, and its
+  <i>Globular</i> Figure, the Rays that pass through it will be dispers'd,
+  and very much scatter'd. Whence CA and DB which before went <i>direct</i>
+  and <i>parallel</i>, will after the refraction in AB, <i>diverge</i> and
+  spread by AP, and BQ; so that as the Rays do meet with more and more of
+  these tinging particles in their way, by so much the more will the pulse
+  of light further lagg behind the clearer pulse, or that which has fewer
+  refractions, and thence the deeper will the colour be, and the fainter
+  the light that is trajected through it; for not onely many Rays are
+  reflected from the surfaces of AB, but those Rays that get through it are
+  very much disordered.</p>
+
+  <p>By this <i>Hypothesis</i> there is no one experiment of colour that I
+  have yet met with, but may be, I conceive, very rationably solv'd, and
+  perhaps, had I time to examine several particulars requisite to the
+  demonstration of it, I might prove it more than probable, for all the
+  experiments about the changes and mixings of colours related in the
+  Treatise of Colours, published by the <i>Incomparable</i> Mr.
+  <i>Boyle</i>, and multitudes of others which I have observ'd, do so
+  easily and naturally flow from those principles, that I am very apt to
+  think it probable, that they own their production to no other
+  <i>secundary</i> cause: As to instance in two or three experiments. In
+  the twentieth Experiment, this <i>Noble Authour</i> has shewn that the
+  deep <i>bluish purple-colour</i> of <i>Violets</i>, may be turn'd into a
+  <i>Green</i>, by <i>Alcalizate Salts</i>, and to a <i>Red</i> by acid;
+  that is, a <i>Purple</i> consists of two colours, a deep <i>Red</i>, and
+  a deep <i>Blue</i>; when the <i>Blue</i> is diluted, or altered, or
+  destroy'd by <i>acid Salts</i>, the <i>Red</i> becomes predominant, but
+  when the <i>Red</i> is diluted by <i>Alcalizate</i>, and the <i>Blue</i>
+  heightned, there is generated a <i>Green</i>; for of a <i>Red</i>
+  diluted, is made a <i>Yellow</i>, and <i>Yellow</i> and <i>Blue</i> make
+  a <i>Green</i>.</p>
+
+  <p>Now, because the <i>spurious</i> pulses which cause a <i>Red</i> and a
+  <i>Blue</i>, do the one follow the clear pulse, and the other precede it,
+  it usually follows, that those <i>Saline</i> refracting bodies which do
+  <i>dilute</i> the colour of the one, do deepen that of the other. And
+  this will be made manifest by almost all kinds of
+  <i>Purples</i>, and many sorts of <i>Greens</i>, both these colours
+  consisting of mixt colours; for if we suppose A and A in the ninth
+  Figure, to represent two pulses of clear light, which follow each other
+  at a convenient distance, AA, each of which has a <i>spurious</i> pulse
+  preceding it, as BB, which makes a <i>Blue</i>, and another following it,
+  as CC, which makes a <i>Red</i>, the one caus'd by tinging particles that
+  have a greater refraction, the other by others that have a less
+  refracting quality then the liquor or <i>Menstruum</i> in which these are
+  dissolv'd, whatsoever liquor does so alter the refraction of the one,
+  without altering that of the other part of the ting'd liquor, must needs
+  very much alter the colour of the liquor; for if the refraction of the
+  <i>dissolvent</i> be increas'd, and the refraction of the tinging
+  particles not altered, then will the preceding <i>spurious</i> pulse be
+  shortned or stopt, and not out-run the clear pulse so much; so that BB
+  will become EE, and the <i>Blue</i> be <i>diluted</i>, whereas the other
+  <i>spurious</i> pulse which follows will be made to lagg much more, and
+  be further behind AA than before, and CC will become <i>ff</i>, and so
+  the <i>Yellow</i> or <i>Red</i> will be heightned.</p>
+
+  <p>A <i>Saline</i> liquor therefore, mixt with another ting'd liquor, may
+  alter the colour of it several ways, either by altering the refraction of
+  the liquor in which the colour swims: or secondly by varying the
+  refraction of the coloured particles, by uniting more intimately either
+  with some particular <i>corpuscles</i> of the tinging body, or with all
+  of them, according as it has a <i>congruity</i> to some more especially,
+  or to all alike: or thirdly, by uniting and interweaving it self with
+  some other body that is already joyn'd with the tinging particles, with
+  which substance it may have a <i>congruity</i>, though it have very
+  little with the particles themselves: or fourthly, it may alter the
+  colour of a ting'd liquor by dis-joyning certain particles which were
+  before united with the tinging particles, which though they were somewhat
+  <i>congruous</i> to these particles, have yet a greater <i>congruity</i>
+  with the newly <i>infus'd Saline menstruum</i>. It may likewise alter the
+  colour by further dissolving the tinging substance into smaller and
+  smaller <i>particles</i>, and so <i>diluting</i> the colour; or by
+  uniting several <i>particles</i> together as in precipitations, and so
+  deepning it, and some such other ways, which many experiments and
+  comparisons of differing trials together, might easily inform one of.</p>
+
+  <p>From these Principles applied, may be made out all the varieties of
+  colours observable, either in liquors, or any other ting'd bodies, with
+  great ease, and I hope intelligible enough, there being nothing in the
+  <i>notion</i> of colour, or in the suppos'd production, but is very
+  conceivable, and may be possible.</p>
+
+  <p>The greatest difficulty that I find against this <i>Hypothesis</i>,
+  is, that there seem to be more distinct colours then two, that is, then
+  Yellow and Blue. This Objection is grounded on this reason, that there
+  are several Reds, which <i>diluted</i>, make not a Saffron or pale
+  Yellow, and therefore Red, or Scarlet seems to be a third colour distinct
+  from a deep degree of Yellow.</p>
+
+  <p>To which I answer, that Saffron affords us a deep Scarlet tincture,
+  which may be <i>diluted</i> into as pale a Yellow as any, either by
+  making a weak solution of the Saffron, by infusing a
+  small parcel of it into a great quantity of liquor, as in spirit of Wine,
+  or else by looking through a very thin quantity of the tincture, and
+  which may be heightn'd into the loveliest Scarlet, by looking through a
+  very thick body of this tincture, or through a thinner parcel of it,
+  which is highly <i>impregnated</i> with the tinging body, by having had a
+  greater quantity of the Saffron dissolv'd in a smaller parcel of the
+  liquor.</p>
+
+  <p>Now, though there may be some particles of other tinging bodies that
+  give a lovely Scarlet also, which though <i>diluted</i> never so much
+  with liquor, or looked on through never so thin a parcel of ting'd
+  liquor, will not yet afford a pale Yellow, but onely a kind of faint Red;
+  yet this is no argument but that those ting'd particles may have in them
+  the faintest degree of Yellow, though we may be unable to make them
+  exhibit it; For that power of being <i>diluted</i> depending upon the
+  divisibility of the ting'd body, if I am unable to make the tinging
+  particles so thin as to exhibit that colour, it does not therefore
+  follow, that the thing is impossible to be done; now, the tinging
+  particles of some bodies are of such a nature, that unless there be found
+  some way of comminuting them into less bulks then the liquor does
+  dissolve them into, all the Rays that pass through them must necessarily
+  receive a tincture so deep, as their appropriate refractions and bulks
+  compar'd with the proprieties of the dissolving liquor must necessarily
+  dispose them to empress, which may perhaps be a pretty deep Yellow, or
+  pale Red.</p>
+
+  <p>And that this is not <i>gratis dictum</i>, I shall add one instance of
+  this kind, wherein the thing is most manifest.</p>
+
+  <p>If you take Blue <i>Smalt</i>, you shall find, that to afford the
+  deepest Blue, which <i>cæteris paribus</i> has the greatest particles or
+  sands; and if you further divide, or grind those particles on a
+  Grindstone, or <i>porphyry</i> stone, you may by <i>comminuting</i> the
+  sands of it, <i>dilute</i> the Blue into as pale a one as you please,
+  which you cannot do by laying the colour thin; for wheresoever any single
+  particle is, it exhibits as deep a Blue as the whole mass. Now, there are
+  other Blues, which though never so much ground, will not be
+  <i>diluted</i> by grinding, because consisting of very small particles,
+  very deeply ting'd, they cannot by grinding be actually separated into
+  smaller particles then the operation of the fire, or some other
+  dissolving <i>menstruum</i>, reduc'd them to already.</p>
+
+  <p>Thus all kind of <i>Metalline</i> colours, whether
+  <i>precipitated</i>, <i>sublim'd</i>, <i>calcin'd</i>, or otherwise
+  prepar'd, are hardly chang'd by grinding, as <i>ultra marine</i> is not
+  more <i>diluted</i>; nor is <i>Vermilion</i> or <i>Red-lead</i> made of a
+  more faint colour by grinding; for the smallest particles of these which
+  I have view'd with my greatest Magnifying-Glass, if they be well
+  enlightned, appear very deeply ting'd with their peculiar colours; nor,
+  though I have magnified and enlightned the particles exceedingly, could I
+  in many of them, perceive them to be transparent, or to be whole
+  particles, but the smallest specks that I could find among well ground
+  <i>Vermilion</i> and <i>Red-lead</i>, seem'd to be a Red mass, compounded
+  of a multitude of less and less motes, which sticking together, compos'd
+  a bulk, not one thousand thousandth part of the smallest visible sand or
+  mote.</p>
+
+  <p>And this I find generally in most <i>Metalline</i> colours, that
+  though they consist of parts so exceedingly small, yet are they very
+  deeply ting'd, they being so ponderous, and having such a multitude of
+  terrestrial particles throng'd into a little room; so that 'tis difficult
+  to find any particle transparent or resembling a pretious stone, though
+  not impossible; for I have observ'd divers such shining and resplendent
+  colours intermixt with the particles of <i>Cinnaber</i>, both natural and
+  artificial, before it hath been ground and broken or flaw'd into
+  <i>Vermilion</i>: As I have also in <i>Orpiment</i>, <i>Red-lead</i>, and
+  <i>Bise</i>, which makes me suppose, that those <i>metalline</i> colours
+  are by grinding, not onely broken and separated actually into smaller
+  pieces, but that they are also flaw'd and brused, whence they, for the
+  most part, become <i>opacous</i>, like flaw'd Crystal or Glass,
+  <i>&amp;c.</i> But for <i>Smalts</i> and <i>verditures</i>, I have been
+  able with a <i>Microscope</i> to perceive their particles very many of
+  them transparent.</p>
+
+  <p>Now, that the others also may be transparent, though they do not
+  appear so to the <i>Microscope</i>, may be made probable by this
+  Experiment: that if you take <i>ammel</i> that is almost <i>opacous</i>,
+  and grind it very well on a <i>Porphyry</i>, or <i>Serpentine</i>, the
+  small particles will by reason of their flaws, appear perfectly
+  <i>opacous</i>; and that 'tis the flaws that produce this
+  <i>opacousness</i>, may be argued from this, that particles of the same
+  <i>Ammel</i> much thicker if unflaw'd will appear somewhat transparent
+  even to the eye; and from this also, that the most transparent and clear
+  Crystal, if heated in the fire, and then suddenly quenched, so that it be
+  all over flaw'd, will appear <i>opacous</i> and white.</p>
+
+  <p>And that the particles of <i>Metalline</i> colours are transparent,
+  may be argued yet further from this, that the Crystals, or
+  <i>Vitriols</i> of all Metals, are transparent, which since they consist
+  of <i>metalline</i> as well as <i>saline</i> particles, those
+  <i>metalline</i> ones must be transparent, which is yet further confirm'd
+  from this, that they have for the most part, <i>appropriate</i> colours;
+  so the <i>vitriol</i> of Gold is Yellow; of Copper, Blue, and sometimes
+  Green; of Iron, green; of Tinn and Lead, a pale White; of Silver, a pale
+  Blue, <i>&amp;.</i></p>
+
+  <p>And next, the <i>Solution</i> of all Metals into <i>menstruums</i> are
+  much the same with the <i>Vitriols</i>, or Crystals. It seems therefore
+  very probable, that those colours which are made by the
+  <i>precipitation</i> of those particles out of the <i>menstruums</i> by
+  transparent <i>precipitating</i> liquors should be transparent also. Thus
+  Gold <i>precipitates</i> with <i>oyl of Tartar</i>, or <i>spirit of
+  Urine</i> into a brown Yellow, Copper with spirit of <i>Urine</i> into a
+  Mucous blue, which retains its transparency. A solution of sublimate (as
+  the same Illustrious Authour I lately mention'd shews in his 40.
+  Experiment) <i>precipitates</i> with oyl of <i>Tartar</i> <i>per
+  deliquium</i>, into an Orange colour'd <i>precipitate</i>; nor is it less
+  probable, that the <i>calcination</i> of those <i>Vitriols</i> by the
+  fire, should have their particles transparent: Thus <i>Saccarum
+  Saturni</i>, or the <i>Vitriol of Lead</i> by <i>calcination</i> becomes
+  a deep Orange-colour'd <i>minium</i>, which is a kind of
+  <i>precipitation</i> by some Salt which proceeds from the fire; common
+  <i>Vitriol</i> <i>calcin'd</i>, yields a deep Brown Red, etc.</p>
+
+  <p>A third Argument, that the particles of Metals are transparent, is,
+  that being <i>calcin'd</i>, and melted with Glass, they tinge the Glass
+  with transparent colours. Thus the <i>Calx</i> of Silver
+  tinges the Glass on which it is anneal'd with a lovely Yellow, or Gold
+  colour, <i>&amp;c.</i></p>
+
+  <p>And that the parts of Metals are transparent, may be farther argued
+  from the transparency of Leaf-gold, which held against the light, both to
+  the naked eye, and the <i>Microscope,</i> exhibits a deep Green. And
+  though I have never seen the other Metals <i>laminated</i> so thin, that
+  I was able to perceive them transparent, yet, for Copper and Brass, if we
+  had the same conveniency for <i>laminating</i> them, as we have for Gold,
+  we might, perhaps, through such plates or leaves, find very differing
+  degrees of Blue, or Green; for it seems very probable, that those Rays
+  that rebound from them ting'd, with a deep Yellow, or pale Red, as from
+  Copper, or with a pale Yellow, as from Brass, have past through them; for
+  I cannot conceive how by reflection alone those Rays can receive a
+  tincture, taking any <i>Hypothesis</i> extant.</p>
+
+  <p>So that we see there may a sufficient reason be drawn from these
+  instances, why those colours which we are unable to <i>dilute</i> to the
+  palest Yellow, or Blue, or Green, are not therefore to be concluded not
+  to be a deeper degree of them; for supposing we had a great company of
+  small <i>Globular</i> essence Bottles, or round Glass bubbles, about the
+  bigness of a Walnut, fill'd each of them with a very deep mixture of
+  Saffron, and that every one of them did appear of a deep Scarlet colour,
+  and all of them together did <i>exhibit</i> at a distance, a deep dy'd
+  Scarlet body. It does not follow, because after we have come nearer to
+  this <i>congeries</i>, or mass, and divided it into its parts, and
+  examining each of its parts severally or apart, we find them to have much
+  the same colour with the whole mats; it does not, I say, therefore
+  follow, that if we could break those <i>Globules</i> smaller, or any
+  other ways come to see a smaller or thinner parcel of the ting'd liquor
+  that fill'd those bubbles, that that ting'd liquor must always appear
+  Red, or of a Scarlet hue, since if Experiment be made, the quite contrary
+  will ensue; for it is capable of being <i>diluted</i> into the palest
+  Yellow.</p>
+
+  <p>Now, that I might avoid all the Objections of this kind, by exhibiting
+  an Experiment that might by ocular proof convince those whom other
+  reasons would not prevail with, I provided me a <i>Prismatical Glass</i>,
+<span class="sidenote">
+<a href="images/scheme-06.png" target="_blank"><i>Schem.</i> 6.</a><br /><i>Fig.</i> 10.
+</span>
+  made hollow, just in the form of a Wedge, such as is represented in the
+  tenth <i>Figure</i> of the sixth <i>Scheme</i>. The two
+  <i>parallelogram</i> sides ABCD, ABEF, which met at a point, were made of
+  the clearest Looking-glass plates well ground and polish'd that I could
+  get; these were joyn'd with hard cement to the <i>triangular</i> sides,
+  BCE, ADF, which were of Wood; the <i>Parallelogram</i> base BCEF,
+  likewise was of Wood joyn'd on to the rest with hard cement, and the
+  whole <i>Prismatical</i> Box was exactly stopt every where, but onely a
+  little hole near the base was left, whereby the Vessel could be fill'd
+  with any liquor, or emptied again at pleasure.</p>
+
+  <p>One of these Boxes (for I had two of them) I fill'd with a pretty deep
+  tincture of <i>Aloes</i>, drawn onely with fair Water, and then stopt the
+  hole with a piece of Wax, then, by holding this Wedge against the Light,
+  and looking through it, it was obvious enough to see the tincture of the
+  liquor near the edge of the Wedge where it was but very thin, to be a
+  pale but well colour'd Yellow, and further and further
+  from the edge, as the liquor grew thicker and thicker, this tincture
+  appear'd deeper and deeper, so that near the blunt end, which was seven
+  Inches from the edge and three Inches and an half thick; it was of a deep
+  and well colour'd Red. Now, the clearer and purer this tincture be, the
+  more lovely will the deep Scarlet be, and the fouler the tincture be, the
+  more dirty will the Red appear; so that some dirty tinctures have
+  afforded their deepest Red much of the colour of burnt Oker or
+  <i>Spanish</i> brown; others as lovely a colour as <i>Vermilion</i>, and
+  some much brighter; but several others, according as the tinctures were
+  worse or more foul, exhibited various kinds of Reds, of very differing
+  degrees.</p>
+
+  <p>The other of these Wedges, I fill'd with a most lovely tincture of
+  Copper, drawn from the filings of it, with spirit of <i>Urine</i>, and
+  this Wedge held as the former against the Light, afforded all manner of
+  Blues, from the faintest to the deepest, so that I was in good hope by
+  these two, to have produc'd all the varieties of colours imaginable; for
+  I thought by this means to have been able by placing the two
+  <i>Parallelogram</i> sides together, and the edges contrary ways, to have
+  so mov'd them to and fro one by another, as by looking through them in
+  several places, and through several thicknesses, I should have
+  compounded, and consequently have seen all those colours, which by other
+  like compositions of colours would have ensued.</p>
+
+  <p>But insteed of meeting with what I look'd for, I met with somewhat
+  more admirable; and that was, that I found my self utterly unable to see
+  through them when placed both together, though they were transparent
+  enough when asunder; and though I could see through twice the thickness,
+  when both of them were fill'd with the same colour'd liquors, whether
+  both with the Yellow, or both with the Blue, yet when one was fill'd with
+  the Yellow, the other with the Blue, and both looked through, they both
+  appear'd dark, onely when the parts near the tops were look'd through,
+  they exhibited Greens, and those of very great variety, as I expected,
+  but the Purples and other colours, I could not by any means make, whether
+  I endeavour'd to look through them both against the Sun, or whether I
+  plac'd them against the hole of a darkned room.</p>
+
+  <p>But notwithstanding this mis-ghessing, I proceeded on with my trial in
+  a dark room, and having two holes near one another, I was able, by
+  placing my Wedges against them, to mix the ting'd Rays that past through
+  them, and fell on a sheet of white Paper held at a convenient distance
+  from them as I pleas'd; so that I could make the Paper appear of what
+  colour I would, by varying the thicknesses of the Wedges, and
+  consequently the tincture of the Rays that past through the two holes,
+  and sometimes also by varying the Paper, that is, insteed of a white
+  Paper, holding a gray, or a black piece of Paper.</p>
+
+  <p>Whence I experimentally found what I had before imagin'd, that all the
+  varieties of colours imaginable are produc'd from several degrees of
+  these two colours, namely, Yellow and Blue, or the mixture of them with
+  light and darkness, that is, white and black. And all those almost
+  infinite varieties which Limners and Painters are able to make by
+  compounding those several colours they lay on their Shels
+  or <i>Palads</i>, are nothing else, but some <i>compositum</i>, made up
+  of some one or more, or all of these four.</p>
+
+  <p>Now, whereas it may here again be objected, that neither can the Reds
+  be made out of the Yellows, added together, or laid on in greater or less
+  quantity, nor can the Yellows be made out of the Reds though laid never
+  so thin; and as for the addition of White or Black, they do nothing but
+  either whiten or darken the colours to which they are added, and not at
+  all make them of any other kind of colour: as for instance,
+  <i>Vermilion</i>, by being temper'd with White Lead, does not at all grow
+  more Yellow, but onely there is made a whiter kind of Red. Nor does
+  Yellow <i>Oker</i>, though laid never so thick, produce the colour of
+  <i>Vermilion</i>, nor though it be temper'd with Black, does it at all
+  make a Red; nay, though it be temper'd with White, it will not afford a
+  fainter kind of Yellow, such as <i>masticut</i>, but onely a whiten'd
+  Yellow; nor will the Blues be <i>diluted</i> or deepned after the manner
+  I speak of, as <i>Indico</i> will never afford so fine a Blue as
+  <i>Ultramarine</i> or <i>Bise</i>; nor will it, temper'd with
+  <i>Vermilion</i>, ever afford a Green, though each of them be never so
+  much temper'd with white.</p>
+
+  <p>To which I answer, that there is a great difference between
+  <i>diluting</i> a colour and whitening of it; for <i>diluting</i> a
+  colour, is to make the colour'd parts more thin, so that the ting'd
+  light, which is made by trajecting those ting'd bodies, does not receive
+  so deep a tincture; but whitening a colour is onely an intermixing of
+  many clear reflections of light among the same ting'd parts; deepning
+  also, and darkning or blacking a colour, are very different; for deepning
+  a colour, is to make the light pass through a greater quantity of the
+  same tinging body; and darkning or blacking a colour, is onely
+  interposing a multitude of dark or black spots among the same ting'd
+  parts, or placing the colour in a more faint light.</p>
+
+  <p>First therefore, as to the former of these operations, that is,
+  diluting and deepning, most of the colours us'd by the Limners and
+  Painters are incapable of, to wit, <i>Vermilion</i> and <i>Red-lead</i>,
+  and <i>Oker</i>, because the ting'd parts are so exceeding small, that
+  the most curious Grindstones we have, are not able to separate them into
+  parts actually divided so small as the ting'd particles are; for looking
+  on the most curiously ground <i>Vermilion</i>, and <i>Oker</i>, and
+  <i>Red-lead</i>, I could perceive that even those small <i>corpuscles</i>
+  of the bodies they left were compounded of many pieces, that is, they
+  seem'd to be small pieces compounded of a multitude of lesser ting'd
+  parts: each piece seeming almost like a piece of Red Glass, or ting'd
+  Crystal all flaw'd; so that unless the Grindstone could actually divide
+  them into smaller pieces then those flaw'd particles were, which
+  compounded that ting'd mote I could see with my <i>Microscope</i>, it
+  would be impossible to <i>dilute</i> the colour by grinding, which,
+  because the finest we have will not reach to do in <i>Vermilion</i> or
+  <i>Oker</i>, therefore they cannot at all, or very hardly be
+  <i>diluted</i>.</p>
+
+  <p>Other colours indeed, whose ting'd particles are such as may be made
+  smaller, by grinding their colour, may be <i>diluted</i>. Thus several of
+  the Blues may be <i>diluted</i>, as <i>Smalt</i>
+  and <i>Bise</i>; and <i>Masticut</i>, which is Yellow, may be made more
+  faint: And even <i>Vermilion</i> it self may, by too much grinding, be
+  brought to the colour of <i>Red-lead</i>, which is but an Orange colour,
+  which is confest by all to be very much upon the Yellow. Now, though
+  perhaps somewhat of this <i>diluting</i> of <i>Vermilion</i> by overmuch
+  grinding may be attributed to the Grindstone, or muller, for that some of
+  their parts may be worn off and mixt with the colour, yet there seems not
+  very much, for I have done it on a Serpentine-stone with a muller made of
+  a Pebble, and yet observ'd the same effect follow.</p>
+
+  <p>And secondly, as to the other of these operations on colours, that is,
+  the deepning of them, Limners and Painters colours are for the most part
+  also uncapable. For they being for the most part <i>opacous</i>; and that
+  <i>opacousness</i>, as I said before, proceeding from the particles,
+  being very much flaw'd, unless we were able to joyn and re-unite those
+  flaw'd particles again into one piece, we shall not be able to deepen the
+  colour, which since we are unable to do with most of the colours which
+  are by Painters accounted <i>opacous</i>, we are therefore unable to
+  deepen them by adding more of the same kind.</p>
+
+  <p>But because all those <i>opacous</i> colours have two kinds of beams
+  or Rays reflected from them, that is, Rays unting'd, which are onely
+  reflected from the outward surface, without at all penetrating of the
+  body, and ting'd Rays which are reflected from the inward surfaces or
+  flaws after they have suffer'd a two-fold refraction; and because that
+  transparent liquors mixt with such <i>corpuscles</i>, do, for the most
+  part, take off the former kind of reflection; therefore these colours
+  mixt with Water or Oyl, appear much deeper than when dry, for most part
+  of that white reflection from the outward surface is remov'd. Nay, some
+  of these colours are very much deepned by the mixture with some
+  transparent liquor, and that because they may perhaps get between those
+  two flaws, and so consequently joyn two or more of those flaw'd pieces
+  together; but this happens but in a very few.</p>
+
+  <p>Now, to shew that all this is not <i>gratis dictum</i>, I shall set
+  down some Experiments which do manifest these things to be probable and
+  likely, which I have here deliver'd.</p>
+
+  <p>For, first, if you take any ting'd liquor whatsoever, especially if it
+  be pretty deeply ting'd, and by any means work it into a froth, the
+  <i>congeries</i> of that froth shall seem an <i>opacous</i> body, and
+  appear of the same colour, but much whiter than that of the liquor out of
+  which it is made. For the abundance of reflections of the Rays against
+  those surfaces of the bubbles of which the froth consists, does so often
+  rebound the Rays backwards, that little or no light can pass through, and
+  consequently the froth appears <i>opacous</i>.</p>
+
+  <p>Again, if to any of these ting'd liquors that will endure the boiling
+  there be added a small quantity of fine flower (the parts of which
+  through the <i>Microscope</i> are plainly enough to be perceiv'd to
+  consist of transparent <i>corpuscles</i>) and suffer'd to boyl till it
+  thicken the liquor, the mass of the liquor will appear <i>opacous</i>,
+  and ting'd with the same colour, but very much whiten'd.</p>
+
+  <p>Thus, if you take a piece of transparent Glass that is well colour'd,
+  and by heating it, and then quenching it in Water, you flaw it all over,
+  it will become <i>opacous</i>, and will exhibit the same colour with
+  which the piece is ting'd, but fainter and whiter.</p>
+
+  <p>Or, if you take a Pipe of this transparent Glass, and in the flame of
+  a Lamp melt it, and then blow it into very thin bubbles, then break those
+  bubbles, and collect a good parcel of those <i>laminæ</i> together in a
+  Paper, you shall find that a small thickness of those Plates will
+  constitute an <i>opacous</i> body, and that you may see through the mass
+  of Glass before it be thus <i>laminated</i>, above four times the
+  thickness: And besides, they will now afford a colour by reflection as
+  other <i>opacous</i> (as they are call'd) colours will, but much fainter
+  and whiter than that of the Lump or Pipe out of which they were made.</p>
+
+  <p>Thus also, if you take <i>Putty</i>, and melt it with any transparent
+  colour'd Glass, it will make it become an <i>opacous</i> colour'd lump,
+  and to yield a paler and whiter colour than the lump by reflection.</p>
+
+  <p>The same thing may be done by a preparation of <i>Antimony</i>, as has
+  been shewn by the Learned <i>Physician</i>, D<sup>r.</sup> <i>C.M.</i> in
+  his Excellent Observations and Notes on <i>Nery's Art of Glass</i>; and
+  by this means all transparent colours become <i>opacous</i>, or
+  <i>ammels</i>. And though by being ground they lose very much of their
+  colour, growing much whiter by reason of the multitude of single
+  reflections from their outward surface, as I shew'd afore, yet the fire
+  that in the nealing or melting re-unites them, and so renews those
+  <i>spurious</i> reflections, removes also those whitenings of the colour
+  that proceed from them.</p>
+
+  <p>As for the other colours which Painters use, which are transparent,
+  and us'd to varnish over all other paintings, 'tis well enough known that
+  the laying on of them thinner or thicker, does very much <i>dilute</i> or
+  deepen their colour.</p>
+
+  <p>Painters Colours therefore consisting most of them of solid particles,
+  so small that they cannot be either re-united into thicker particles by
+  any Art yet known, and consequently cannot be deepned; or divided into
+  particles so small as the flaw'd particles that exhibit that colour, much
+  less into smaller, and consequently cannot be <i>diluted</i>; It is
+  necessary that they which are to imitate all kinds of colours, should
+  have as many degrees of each colour as can be procur'd.</p>
+
+  <p>And to this purpose, both Limners and Painters have a very great
+  variety both of Yellows and Blues, besides several other colour'd bodies
+  that exhibit very compounded colours, such as Greens and Purples; and
+  others that are compounded of several degrees of Yellow, or several
+  degrees of Blue, sometimes unmixt, and sometimes compounded with several
+  other colour'd bodies.</p>
+
+  <p>The Yellows, from the palest to the deepest Red or Scarlet, which has
+  no intermixture of Blue, are <i>pale and deep Masticut, Orpament, English
+  Oker, brown Oker, Red Lead, and Vermilion, burnt English Oker, and burnt
+  brown Oker,</i> which last have a mixture of dark or dirty parts with
+  them, <i>&amp;c.</i></p>
+
+  <p>Their Blues are several kinds of <i>Smalts</i>, and <i>Verditures</i>,
+  and <i>Bise</i>, and <i>Ultramarine</i>, and <i>Indico</i>, which last
+  has many dirty or dark parts intermixt with it.</p>
+
+  <p>Their compounded colour'd bodies, as <i>Pink</i>, and
+  <i>Verdigrese</i>, which are Greens, the one a <i>Popingay</i>, the other
+  a <i>Sea-green</i>; then <i>Lac</i>, which is a very lovely
+  <i>Purple</i>.</p>
+
+  <p>To which may be added their Black and White, which they also usually
+  call Colours, of each of which they have several kinds, such as <i>Bone
+  Black</i>, made of <i>Ivory</i> burnt in a close Vessel, and <i>Blue
+  Black</i>, made of the small coal of <i>Willow</i>, or some other Wood;
+  and <i>Cullens earth</i>, which is a kind of brown Black, &amp;c. Their
+  usual Whites are either artificial or natural <i>White Lead</i>, the last
+  of which is the best they yet have, and with the mixing and tempering
+  these colours together, are they able to make an imitation of any colour
+  whatsoever: Their Reds or deep Yellows, they can <i>dilute</i> by mixing
+  pale Yellows with them, and deepen their pale by mixing deeper with them;
+  for it is not with <i>Opacous</i> colours as it is with transparent,
+  where by adding more Yellow to yellow, it is deepned, but in
+  <i>opacous</i> <i>diluted</i>. They can whiten any colour by mixing White
+  with it, and darken any colour by mixing Black, or some dark and dirty
+  colour. And in a word, most of the colours, or colour'd bodies they use
+  in Limning and Painting, are such, as though mixt with any other of their
+  colours, they preserve their own hue, and by being in such very smal
+  parts dispers'd through the other colour'd bodies, they both, or
+  altogether represent to the eye a <i>compositum</i> of all; the eye being
+  unable, by reason of their smalness, to distinguish the peculiarly
+  colour'd particles, but receives them as one intire <i>compositum</i>:
+  whereas in many of these, the <i>Microscope</i> very easily distinguishes
+  each of the compounding colours distinct, and exhibiting its own
+  colour.</p>
+
+  <p>Thus have I by gently mixing <i>Vermilion</i> and <i>Bise</i> dry,
+  produc'd a very fine Purple, or mixt colour, but looking on it with the
+  <i>Microscope</i>, I could easily distinguish both the Red and the Blue
+  particles, which did not at all produce the <i>Phantasm</i> of
+  Purple.</p>
+
+  <p>To summ up all therefore in a word, I have not yet found any solid
+  colour'd body, that I have yet examin'd, perfectly <i>opacous</i>; but
+  those that are least transparent are <i>Metalline</i> and <i>Mineral</i>
+  bodies, whose particles generally, seeming either to be very small, or
+  very much flaw'd, appear for the most part <i>opacous</i>, though there
+  are very few of them that I have look'd on with a <i>Microscope</i>, that
+  have not very plainly or circumstantially manifested themselves
+  transparent.</p>
+
+  <p>And indeed, there seem to be so few bodies in the world that are <i>in
+  minimis</i> opacous, that I think one may make it a rational
+  <i>Query</i>, Whether there be any body absolutely thus <i>opacous</i>?
+  For I doubt not at all (and I have taken notice of very many
+  circumstances that make me of this mind) that could we very much improve
+  the <i>Microscope</i>, we might be able to see all those bodies very
+  plainly transparent, which we now are fain onely to ghess at by
+  circumstances. Nay, the Object Glasses we yet make use of are such, that
+  they make many transparent bodies to the eye, seem
+  <i>opacous</i> through them, which if we widen the Aperture a little, and
+  cast more light on the objects, and not charge the Glasses so deep, will
+  again disclose their transparency.</p>
+
+  <p>Now, as for all kinds of colours that are dissolvable in Water, or
+  other liquors, there is nothing so manifest, as that all those ting'd
+  liquors are transparent; and many of them are capable of being
+  <i>diluted</i> and compounded or mixt with other colours, and divers of
+  them are capable of being very much chang'd and heightned, and fixt with
+  several kinds of <i>Saline menstruums</i>. Others of them upon
+  compounding, destroy or vitiate each others colours, and
+  <i>precipitate</i>, or otherwise very much alter each others tincture. In
+  the true ordering and <i>diluting</i>, and deepning, and mixing, and
+  fixing of each of which, consists one of the greatest mysteries of the
+  Dyers; of which particulars, because our <i>Microscope</i> affords us
+  very little information, I shall add nothing more at present; but onely
+  that with a very few tinctures order'd and mixt after certain ways, too
+  long to be here set down, I have been able to make an appearance of all
+  the various colours imaginable, without at all using the help of
+  <i>Salts</i>, or <i>Saline menstruums</i> to vary them.</p>
+
+  <p>As for the mutation of Colours by <i>Saline menstruums</i>, they have
+  already been so fully and excellently handled by the lately mention'd
+  Incomparable <i>Authour</i>, that I can add nothing, but that of a
+  multitude of trials that I made, I have found them exactly to agree with
+  his Rules and Theories; and though there may be infinite instances, yet
+  may they be reduc'd under a few Heads, and compris'd within a very few
+  Rules. And generally I find, that <i>Saline menstruums</i> are most
+  operative upon those colours that are Purple, or have some degree of
+  Purple in them, and upon the other colours much less. The <i>spurious</i>
+  pulses that compose which, being (as I formerly noted) so very neer the
+  middle between the true ones, that a small variation throws them both to
+  one side, or both to the other, and so consequently must make a vast
+  mutation in the formerly appearing Colour.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXI" id="obsXI">XI</a>. <i>Of </i>Figures<i> observ'd in small Sand.</i></h3>
+
+  <p>Sand generally seems to be nothing else but exceeding small Pebbles,
+  or at least some very small parcels of a bigger stone; the whiter kind
+  seems through the <i>Microscope</i> to consist of small transparent
+  pieces of some <i>pellucid</i> body, each of them looking much like a
+  piece of <i>Alum</i>, or <i>Salt Gem</i>; and this kind of Sand is angled
+  for the most part irregularly, without any certain shape, and the
+  <i>granules</i> of it are for the most part flaw'd, through amongst many
+  of them it is not difficult to find some that are perfectly
+  <i>pellucid</i>, like a piece of clear Crystal, and divers likewise most
+  curiously shap'd, much after the manner of the bigger <i>Stiriæ</i> of
+  Crystal, or like the small Diamants I observ'd in certain Flints, of
+  which I shall by and by relate; which last particular seems to argue,
+  that this kind of Sand is not made by the comminution of
+  greater transparent Crystaline bodies, but by the <i>concretion</i> or
+  <i>coagulation</i> of Water, or some other fluid body.</p>
+
+  <p>There are other kinds of courser Sands, which are browner, and have
+  their particles much bigger; these, view'd with a <i>Microscope</i>, seem
+  much courser and more <i>opacous</i> substances, and most of them are of
+  some irregularly rounded Figures; and though they seem not so
+  <i>opacous</i> as to the naked eye, yet they seem very foul and cloudy,
+  but neither do these want curiously transparent, no more than they do
+  regularly figur'd and well colour'd particles, as I have often found.</p>
+
+  <p>There are multitudes of other kinds of Sands, which in many
+  particulars, plainly enough discoverable by the <i>Microscope</i>, differ
+  both from these last mention'd kinds of Sands, and from one another:
+  there seeming to be as great variety of Sands, as there is of Stones. And
+  as amongst Stones some are call'd precious from their excellency, so also
+  are there Sands which deserve the same Epithite for their beauty; for
+  viewing a small parcel of <i>East-India</i> Sand (which was given me by
+  my highly honoured friend, Mr. <i>Daniel Colwall</i>) and, since that,
+  another parcel, much of the same kind, I found several of them, both very
+  transparent like precious Stones, and regularly figur'd like Crystal,
+  <i>Cornish</i> Diamants, some Rubies, <i>&amp;c.</i> and also ting'd with
+  very lively and deep colours, like <i>Rubys</i>, <i>Saphyrs</i>,
+  <i>Emeralds</i>, <i>&amp;c.</i> These kinds of granuls I have often found
+  also in <i>English</i> Sand. And 'tis easie to make such a counterfeit
+  Sand with deeply ting'd Glass, Enamels and Painters colours.</p>
+
+  <p>It were endless to describe the multitudes of Figures I have met with
+  in these kind of minute bodies, such as <i>Spherical</i>, <i>Oval</i>,
+  <i>Pyramidal</i>, <i>Conical</i>, <i>Prismatical</i>, of each of which
+  kinds I have taken notice.</p>
+
+  <p>But amongst many others, I met with none more observable than this
+<span class="sidenote">
+<a href="images/scheme-05.png" target="_blank"><i>Schem.</i> 5.</a><br /><i>Fig.</i> X.
+</span>
+  pretty Shell (described in the <i>Figure</i> X. of the fifth
+  <i>Scheme</i>) which, though as it was light on by chance, deserv'd to
+  have been omitted (I being unable to direct any one to find the like) yet
+  for its rarity was it not inconsiderable, especially upon the account of
+  the information it may afford us. For by it we have a very good instance
+  of the curiosity of Nature in another kind of Animals which are remov'd,
+  by reason of their minuteness, beyond the reach of our eyes, so that as
+  there are several sorts of Insects, as Mites, and others, so small as not
+  yet to have had any names; (some of which I shall afterwards describe)
+  and small Fishes, as Leeches in Vineger; and smal vegetables, as Moss,
+  and Rose-Leave-plants; and small Mushroms, as mould: so are there, it
+  seems, small Shel-fish likewise, Nature shewing her curiosity in every
+  Tribe of <i>Animals</i>, <i>Vegetables</i>, and <i>Minerals</i>.</p>
+
+  <p>I was trying several small and single Magnifying Glasses, and casually
+  viewing a parcel of white Sand, when I perceiv'd one of the grains
+  exactly shap'd and wreath'd like a Shell, but endeavouring to distinguish
+  it with my naked eye, it was so very small, that I was fain again to make
+  use of the Glass to find it; then, whilest I thus look'd on it, with a
+  Pin I separated all the rest of the granules of Sand, and found it
+  afterwards to appear to the naked eye an exceeding small white spot, no
+  bigger than the point of a Pin. Afterwards I view'd it
+  every way with a better <i>Microscope</i> and found it on both sides, and
+  edge-ways, to resemble the Shell of a small Water-Snail with a flat
+  spiral Shell: it had twelve wreathings, <i>a</i>, <i>b</i>, <i>c</i>,
+  <i>d</i>, <i>e</i>, &amp;c. all very proportionably growing one less than
+  another toward the middle or center of the Shell, where there was a very
+  small round white spot. I could not certainly discover whether the Shell
+  were hollow or not, but it seem'd fill'd with somewhat, and 'tis probable
+  that it might be <i>petrify'd</i> as other larger Shels often are, such
+  as are mention'd in the seventeenth <i>Observation</i>.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXII" id="obsXII">XII</a>. <i>Of </i>Gravel<i> in Urine.</i></h3>
+
+  <p>I Have often observ'd the Sand or Gravel of Urine, which seems to be a
+  <i>tartareous</i> substance, generated out of a <i>saline</i> and a
+  <i>terrestrial</i> substance <i>crystalliz'd</i> together, in the form of
+  <i>Tartar</i>, sometimes sticking to the sides of the <i>Urinal</i>, but
+  for the most part sinking to the bottom, and there lying in the form of
+  coorse common Sand; these, through the <i>Microscope</i>, appear to be a
+  company of small bodies, partly transparent and partly <i>opacous</i>,
+  some White, some Yellow, some Red, others of more brown and duskie
+  colours.</p>
+
+  <p>The Figure of them is for the most part flat, in the manner of Slats
+  or such like plated Stones, that is, each of them seem to be made up of
+  several other thinner Plates, much like <i>Muscovie Glass</i>, or
+  <i>Englsh Sparr</i> to the last of which, the white plated Gravel seems
+  most likely; for they seem not onely plated like that, but their sides
+  shap'd also into <i>Rhombs</i>, <i>Rhomboeids</i>, and sometimes into
+  <i>Rectangles</i> and <i>Squares</i>. Their bigness and Figure may be
+<span class="sidenote">
+<a href="images/scheme-07.png" target="_blank"><i>Schem.</i> 7.</a><br /><i>Fig.</i> 2.
+</span>
+  seen in the second <i>Figure</i> of the seventh <i>Plate</i>, which
+  represents about a dozen of them lying upon a plate ABCD, some of which,
+  as <i>a</i>, <i>b</i>, <i>c</i>, <i>d</i> seem'd more regular than the
+  rest, and <i>e</i>, which was a small one, sticking on the top of
+  another, was a perfet <i>Rhomboeid</i> on the top, and had four
+  <i>Rectangular</i> sides.</p>
+
+  <p>The line E which was the the measure of the <i>Microscope</i>, is 1/32
+  part of an <i>English</i> Inch, so that the greatest bredth of any of
+  them, exceeded not 1/128 part of an Inch.</p>
+
+  <p>Putting these into several liquors, I found <i>oyl of Vitriol</i>,
+  <i>Spirit of Urine</i>, and several other <i>Saline menstruums</i> to
+  dissolve them; and the first of these in less than a minute without
+  <i>Ebullition</i>, Water, and several other liquors, had no sudden
+  operation upon them. This I mention, because those liquors that dissolve
+  them, first make them very white, not <i>vitiating</i>, but rather
+  rectifying their Figure, and thereby make them afford a very pretty
+  object for the <i>Microscope</i>.</p>
+
+  <p>How great an advantage it would be to such as are troubled with the
+  Stone, to find some <i>menstruum</i> might dissolve them without hurting
+  the Bladder, is easily imagin'd, since some <i>injections</i> made of
+  such bodies might likewise dissolve the stone, which seems much of the
+  same nature.</p>
+
+  <p>It may therefore, perhaps, be worthy some Physicians enquiry, whether
+  there may not be something mixt with the Urine in which the Gravel or
+  Stone lies, which may again make it dissolve it, the first of which seems
+  by it's regular Figures to have been sometimes <i>Crystalliz'd</i> out of
+  it. For whether this <i>Crystallization</i> be made in the manner as
+  <i>Alum</i>, <i>Peter</i>, &amp;c. are <i>crystallized</i> out of a
+  cooling liquor, in which, by boyling they have been dissolv'd; or whether
+  it be made in the manner of <i>Tartarum Vitriolatum</i>, that is, by the
+  <i>Coalition</i> of an <i>acid</i> and a <i>Sulphureous</i> substance, it
+  seems not impossible, but that the liquor it lies in, may be again made a
+  <i>dissolvent</i> of it. But leaving these inquiries to Physicians or
+  Chymists, to whom it does more properly belong, I shall proceed.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXIII" id="obsXIII">XIII</a>. <i>Of the small </i>Diamants<i>, or </i>Sparks<i> in </i>Flints<i>.</i></h3>
+
+  <p>Chancing to break a Flint stone in pieces, I found within it a certain
+  cavity all crusted over with a very pretty candied substance, some of the
+  parts of which, upon changing the posture of the Stone, in respect of the
+  <i>Incident</i> light, exhibited a number of small, but very vivid
+  reflections; and having made use of my <i>Microscope</i>, I could
+  perceive the whole surface of that cavity to be all beset with a
+  multitude of little <i>Crystaline</i> or <i>Adamantine</i> bodies, so
+  curiously shap'd, that it afforded a not unpleasing object.</p>
+
+  <p>Having considered those vivid <i>repercussions</i> of light, I found
+  them to be made partly from the plain external surface of these regularly
+  figured bodies (which afforded the vivid reflexions) and partly to be
+  made from within the somewhat <i>pellucid</i> body, that is, from some
+  surface of the body, opposite to that superficies of it which was next
+  the eye.</p>
+
+  <p>And because these bodies were so small, that I could not well come to
+  make Experiments and Examinations of them, I provided me several small
+  <i>stiriæ</i> of Crystals or Diamants, found in great quantities in
+  <i>Cornwall</i> and are therefore commonly called <i>Cornish
+  Diamants</i>: these being very <i>pellucid</i>, and growing in a hollow
+  cavity of a Rock (as I have been several times informed by those that
+  have observ'd them) much after the same manner as these do in the Flint,
+  and having besides their outward surface very regularly shap'd, retaining
+  very near the same Figures with some of those I observ'd in the other,
+  became a convenient help to me for the Examination of the proprieties of
+  those kinds of bodies.</p>
+
+  <p>And first for the Reflections, in these I found it very observable,
+  That the brightest reflections of light proceeded from within the
+  <i>pellucid</i> body; that is, that the Rays admitted through the
+  <i>pellucid</i> substance in their getting out on the opposite side, were
+  by the contiguous and strong reflecting surface of the Air very vividly
+  reflected, so that more Rays were reflected to the eye by this surface,
+  though the Ray in entring and getting out of the Crystal had suffer'd a
+  double refraction, than there were from the outward surface of the Glass
+  where the Ray had suffer'd no reflection at all.</p>
+
+  <p>And that this was the surface of the Air that gave so vivid a
+  <i>re-percussion</i> I try'd by this means I sunk half of a <i>stiria</i>
+  in Water, so that only Water was contiguous to the under surface, and
+  then the internal reflection was so exceedingly faint, that it was scarce
+  discernable. Again, I try'd to alter this vivid reflection by keeping off
+  the Air, with a body not fluid, and that was by rubbing and holding my
+  finger very hard against the under surface, so as in many places the pulp
+  of my finger did touch the Glass, without any <i>interjacent</i> air
+  between, then observing the reflection, I found, that wheresoever my
+  finger or skin toucht the surface, from that part there was no
+  reflection, but in the little furrows or creases of my skin, where there
+  remain'd little small lines of air, from them was return'd a very vivid
+  reflection as before. I try'd further, by making the surface of very pure
+  Quicksilver to be contiguous to the under surface of this <i>pellucid</i>
+  body, and then the reflection from that was so exceedingly more vivid
+  than from the air, as the reflection from air was than the reflection
+  from the Water; from all which trials I plainly saw, that the strong
+  reflecting air was the cause of this <i>Phænomenon</i>.</p>
+
+  <p>And this agrees very well with the <i>Hypothesis</i> of light and
+  <i>Pellucid</i> bodies which I have mention'd in the description of
+  <i>Muscovy-glass</i>; for we there suppose Glass to be a <i>medium</i>,
+  which does less resist the pulse of light, and consequently, that most of
+  the Rays incident on it enter into it, and are refracted towards the
+  <i>perpendicular</i>; whereas the air I suppose to be a body that does
+  more resist it, and consequently more are <i>re-percuss'd</i> then do
+  enter it: the same kind of trials have I made, with <i>Crystalline
+  Glass</i>, with drops of fluid bodies, and several other ways, which do
+  all seem to agree very exactly with this <i>Theory</i>. So that from this
+  Principle well establish'd, we may deduce severall Corollaries not
+  unworthy observation.</p>
+
+  <p>And the first is; that it plainly appears by this, that the production
+  of the Rainbow is as much to be ascribed to the reflection of the concave
+  surface of the air, as to the refraction of the <i>Globular</i> drops:
+  this will be evidently manifest by these Experiments, if you
+  <i>foliate</i> that part of a Glass-ball that is to reflect an
+  <i>Iris</i>, as in the <i>Cartesian</i> Experiment, above mention'd, the
+  reflections will be abundantly more strong, and the colours more vivid:
+  and if that part of the surface be touch'd with Water, scarce affords any
+  sensible colour at all.</p>
+
+  <p>Next we learn, that the great reason why <i>pellucid</i> bodies beaten
+  small are white, is from the multitude of reflections, not from the
+  particles of the body, but from the <i>contiguous</i> surface of the air.
+  And this is evidently manifested, by filling the <i>Interstitia</i> of
+  those powder'd bodies with Water, whereby their whiteness presently
+  disappears. From the same reason proceeds the whiteness of many kinds of
+  Sands, which in the <i>Microscope</i> appear to be made up of a multitude
+  of little <i>pellucid</i> bodies, whose brightest reflections may by the
+  <i>Microscope</i> be plainly perceiv'd to come from their internal
+  surfaces; and much of the whiteness of it may be destroy'd by the
+  affusion of fair Water to be contiguous to those surfaces.</p>
+
+  <p>The whiteness also of froth, is for the most part to be ascribed to
+  the reflection of the light from the surface of
+  the air within the Bubbles, and very little to the reflection from the
+  surface of the Water it self: for this last reflection does not return a
+  quarter so many Rays, as that which is made from the surface of the air,
+  as I have certainly found by a multitude of Observations and
+  Experiments.</p>
+
+  <p>The whiteness of <i>Linnen</i>, <i>Paper</i>, <i>Silk</i>, &amp;c.
+  proceeds much from the same reason, as the <i>Microscope</i> will easily
+  discover; for the Paper is made up of an abundance of <i>pellucid</i>
+  bodies, which afford a very plentifull reflection from within, that is,
+  from the concave surface of the air contiguous to its component
+  particles; wherefore by the affusion of Water, Oyl, Tallow, Turpentine,
+  <i>&amp;c.</i> all those reflections are made more faint, and the beams
+  of light are suffer'd to traject &amp; run through the Paper more
+  freely.</p>
+
+  <p>Hence further we may learn the reason of the whiteness of many bodies,
+  and by what means they maybe in part made <i>pellucid</i>: As white
+  Marble for instance, for this body is composed of a <i>pellucid</i> body
+  exceedingly flaw'd, that is, there are abundance of thin, and very fine
+  cracks or chinks amongst the multitude of particles of the body, that
+  contain in them small parcels of air, which do so <i>re-percuss</i> and
+  drive back the penetrating beams, that they cannot enter very deep within
+  that body; which the <i>Microscope</i> does plainly inform us to be made
+  up of a <i>Congeries</i> of <i>pellucid</i> particles. And I further
+  found it somewhat more evidently by some attempts I made towards the
+  making transparent Marble, for by heating the Stone a little, and baking
+  it in Oyl, Turpentine, Oyl of Turpentine, <i>&amp;c.</i>, I found that I
+  was able to see much deeper into the body of Marble then before; and one
+  trial, which was not with an unctuous substance, succeeded better than
+  the rest, of which, when I have a better opportunity, I shall make
+  further trial.</p>
+
+  <p>This also gives us a probable reason of the so much admired
+  <i>Phænomena</i>, of the <i>Oculus Mundi</i>, an <i>Oval</i> stone, which
+  commonly looks like white Alabaster, but being laid a certain time in
+  Water, it grows <i>pellucid</i>, and transparent, and being suffer'd to
+  lie again dry, it by degrees loses that transparency, and becomes white
+  as before. For the Stone being of a hollow spongie nature, has in the
+  first and last of these appearances, all those pores fill'd with the
+  obtunding and reflecting air; whereas in the second, all those pores are
+  fill'd with a <i>medium</i> that has much the same refraction with the
+  particles of the Stone, and therefore those two being <i>contiguous</i>,
+  make, as 'twere, one <i>continued medium</i>, of which more is said in
+  the 15. <i>Observation</i>.</p>
+
+  <p>There are a multitude of other <i>Phænomena</i>, that are produc'd
+  from this same Principle, which as it has not been taken notice of by any
+  yet that I know, so I think, upon more diligent observation, will it not
+  be found the least considerable. But I have here onely time to hint
+  <i>Hypotheses</i>, and not to prosecute them so fully as I could wish;
+  many of them having a vast extent in the production of a multitude of
+  <i>Phænomena</i>, which have been by others, either not attempted to be
+  explain'd, or else attributed to some other cause than what I have
+  assign'd, and perhaps than the right; and therefore I shall leave this to
+  the prosecution of such as have more leisure: onely before
+  I leave it, I must not pretermit to hint, that by this Principle,
+  multitudes of the <i>Phænomena</i> of the air, as about <i>Mists</i>,
+  <i>Clouds</i>, <i>Meteors</i>, <i>Haloes</i>, &amp;c. are most plainly
+  and (perhaps) truly explicable; multitudes also of the <i>Phænomena</i>
+  in colour'd bodies, as liquors, <i>&amp;c.</i> are deducible from it.</p>
+
+  <p>And from this I shall proceed to a second considerable
+  <i>Phænomenon</i> which these Diamants exhibit, and that is the
+  regularity of their <i>Figure</i>, which is a propriety not less general
+  than the former, It comprising within its extent, all kinds of
+  <i>Metals</i>, all kinds of <i>Minerals</i>, most <i>Precious stones</i>,
+  all kinds of <i>Salts</i>, multitudes of <i>Earths</i>, and almost all
+  kinds of <i>fluid bodies</i>. And this is another propiety, which, though
+  a little superficially taken notice of by some, has not, that I know,
+  been so much as attempted to be explicated by any.</p>
+
+  <p>This propriety of bodies, as I think it the most worthy, and next in
+  order to be consider'd after the contemplation of the <i>Globular
+  Figure</i>, so have I long had a desire as wel as a determination to have
+  prosecuted it if I had had an opportunity, having long since propos'd to
+  my self the method of my enquiry therein, it containing all the
+  allurements that I think any enquiry is capable of: For, first I take it
+  to proceed from the most simple principle that any kind of form can come
+  from, next the <i>Globular</i>, which was therefore the first I set upon,
+  and what I have therein perform'd, I leave the Judicious Reader to
+  determine. For as that form proceeded from a propiety of fluid bodies,
+  which I have call'd <i>Congruity</i>, or <i>Incongruity</i>; so I think,
+  had I time and opportunity, I could make probable, that all these regular
+  Figures that are so conspicuously <i>various</i> and <i>curious</i>, and
+  do so adorn and beautifie such multitudes of bodies, as I have above
+  hinted, arise onely from three or four several positions or postures of
+  <i>Globular</i> particles, and those the most plain, obvious, and
+  necessary conjunctions of such figur'd particles that are possible, so
+  that supposing such and such plain and obvious causes concurring the
+  <i>coagulating particles</i> must necessarily compose a body of such a
+  determinate regular Figure, and no other, and this with as much necessity
+  and obviousness as a fluid body encompast with a <i>Heterogeneous</i>
+  fluid must be protruded into a <i>Spherule</i> or <i>Globe</i>. And this
+  I have <i>ad oculum</i> demonstrated with a company of bullets, and some
+  few other very simple bodies; so that there was not any regular Figure,
+  which I have hitherto met withall, of any of those bodies that I have
+  above named, that I could not with the composition of bullets or
+  globules, and one or two other bodies, imitate, even almost by shaking
+  them together. And thus for instance may we find that the <i>Globular</i>
+  bullets will of themselves, if put on an inclining plain, so that they
+  may run together, naturally run into a <i>triangular</i> order, composing
+  all the variety of figures that can be imagin'd to be made out of
+  <i>æquilateral triangles</i>; and such will you find, upon trial, all the
+  Surfaces of <i>Alum</i> to be compos'd of: For three bullets lying on a
+  plain, as close to one another as they can compose an
+<span class="sidenote">
+<a href="images/scheme-07.png" target="_blank"><i>Schem.</i> 7.</a><br /><i>Fig.</i> A. <i>&amp;c.</i>
+</span>
+  <i>æquilatero-triangular</i> form, as in A in the 7. <i>Scheme</i>. If a
+  fourth be joyn'd to them on either side as closely as it can, they four
+  compose the most regular Rhombus consisting of two <i>æquilateral
+  triangles</i>, as B. If a fifth be joyn'd to them on either
+  side in as close a position as it can, which is the propriety of the
+  <i>Texture</i>, it makes a <i>Trapezium</i>, or four-sided Figure, two of
+  whole angles are 120. and two 60. degrees, as C. If a sixth be added, as
+  before, either it makes an <i>æquilateral triangle</i>, as D, or a
+  Rhomboeid, as E, or an <i>Hex-angular Figure</i>, as F, which is compos'd
+  of two <i>primary Rhombes</i>. If a seventh be added, it makes either an
+  <i>æquilatero-hexagonal</i> Figure, as G, or some kind of six-sided
+  <i>Figure</i>, as H, or I. And though there be never so many placed
+  together, they may be rang'd into some of these lately mentioned Figures,
+  all the angles of which will be either <i>60</i>. degrees, or 120. as the
+  figure K. which is an <i>æquiangular hexagonal</i> Figure is compounded
+  of 12. <i>Globules</i>, or may be of 25, or 27, or 36, or 42,
+  <i>&amp;c.</i> and by these kinds of texture, or position of globular
+  bodies, may you find out all the variety of regular shapes, into which
+  the smooth surfaces of <i>Alum</i> are form'd, as upon examination any
+  one may easily find; nor does it hold only in superficies, but in
+  solidity also, for it's obvious that a fourth <i>Globule</i> laid upon
+  the third in this texture, composes a regular <i>Tetrahedron</i>, which
+  is a very usual Figure of the <i>Crystals</i> of <i>Alum</i>. And (to
+  hasten) there is no one Figure into which <i>Alum</i> is observ'd to be
+  crystallized, but may by this texture of <i>Globules</i> be imitated, and
+  by no other.</p>
+
+  <p>I could instance also in the Figure of <i>Sea-salt</i>, and
+  <i>Sal-gem</i>, that it is compos'd of a texture of <i>Globules</i>,
+  placed in a <i>cubical</i> form, as L, and that all the Figures of those
+  Salts may be imitated by this texture of <i>Globules</i> and by no other
+  whatsoever. And that the forms of <i>Vitriol</i> and of
+  <i>Salt-Peter</i>, as also of <i>Crystal</i>, <i>Hore-frost</i>, &amp;c.
+  are compounded of these two textures, but modulated by certain
+  proprieties: But I have not here time to insist upon, as I have not
+  neither to shew by what means <i>Globules</i> come to be thus context,
+  and what those <i>Globules</i> are, and many other particulars requisite
+  to a full and intelligible explication of this propriety of bodies. Nor
+  have I hitherto found indeed an opportunity of prosecuting the inquiry so
+  farr as I design'd; nor do I know when I may, it requiring abundance of
+  time, and a great deal of assistance to go through with what I design'd;
+  the model of which was this:</p>
+
+  <p>First, to get as exact and full a collection as I could, of all the
+  differing kinds of Geometrical figur'd bodies, some three or four several
+  bodies of each kind.</p>
+
+  <p>Secondly, with them to get as exact a History as possibly I could
+  learn of their places of Generation or finding, and to enquire after as
+  many circumstances that tended to the Illustrating of this Enquiry, as
+  possibly I could observe.</p>
+
+  <p>Thirdly, to make as many trials as upon experience I could find
+  requisite, in Dissolutions and Coagulations of several crystallizing
+  Salts; for the needfull instruction and information in this Enquiry.</p>
+
+  <p>Fourthly, to make several trials on divers other bodies, as Metals,
+  Minerals, and Stones, by dissolving them in several <i>Menstruums</i>,
+  and crystalizing them, to see what Figures would arise from those several
+  <i>Compositums</i>.</p>
+
+  <p>Fifthly, to make Compositions and Coagulations of several Salts
+  together into the same mass, to observe of what Figure the product of
+  them would be; and in all, to note as many circumstances as I should
+  judge conducive to my Enquiry.</p>
+
+  <p>Sixthly, to enquire the closeness or rarity of the texture of these
+  bodies, by examining their gravity, and their refraction,
+  <i>&amp;c.</i></p>
+
+  <p>Seventhly, to enquire particularly what operations the fire has upon
+  several kinds of Salts, what changes it causes in their Figures,
+  Textures, or Energies.</p>
+
+  <p>Eighthly, to examine their manner of dissolution, or acting upon those
+  bodies dissoluble in them; The texture of those bodies before and after
+  the process. And this for the History.</p>
+
+  <p>Next for the Solution, To have examin'd by what, and how many means,
+  such and such Figures, actions and effects could be produc'd
+  possibly.</p>
+
+  <p>And lastly, from all circumstances well weigh'd, I should have
+  endeavoured to have shewn which of them was most likely, and (if the
+  informations by these Enquiries would have born it) to have demonstrated
+  which of them it must be, and was.</p>
+
+  <p>But to proceed, As I believe it next to the Globular the most simple;
+  so do I, in the second place, judge it not less pleasant; for that which
+  makes an Enquiry pleasant, are, first a noble <i>Inventum</i> that
+  promises to crown the successfull endeavour; and such must certainly the
+  knowledge of the efficient and concurrent causes of all these curious
+  Geometrical Figures be, which has made the Philosophers hitherto to
+  conclude nature in these things to play the Geometrician, according to
+  that saying of <i>Plato</i>, <span lang="el" title="Ho Theos geometrei"
+  >&#x201B;&#x39F; &#x398;&#x3B5;&#x3BF;&#x3C2;
+  &#x3B3;&#x3B5;&#x3BF;&#x3BC;&#x3B5;&#x3C4;&#x3C1;&#x3B5;&#x3B9;</span>.
+  Or next, a great variety of matter in the Enquiry; and here we meet with
+  nothing less than the <i>Mathematicks</i> of nature, having every day a
+  new Figure to contemplate, or a variation of the same in another
+  body,</p>
+
+  <p>Which do afford us a third thing, which will yet more sweeten the
+  Enquiry, and that is, a multitude of information; we are not so much to
+  grope in the dark, as in most other Enquiries, where the <i>Inventum</i>
+  is great; for having such a multitude of instances to compare, and such
+  easie ways of generating, or compounding and of destroying the form, as
+  in the <i>Solution</i> and <i>Crystallization</i> of Salts, we cannot but
+  learn plentifull information to proceed by. And this will further appear
+  from the universality of the Principle which Nature has made use of
+  almost in all inanimate bodies. And therefore, as the contemplation of
+  them all conduces to the knowledg of any one; so from a Scientifical
+  knowledge of any one does follow the fame of all, and every one.</p>
+
+  <p>And fourthly, for the usefulness of this knowledge, when acquir'd;
+  certainly none can doubt, that considers that it caries us a step forward
+  into the Labirinth of Nature, in the right way towards the end we propose
+  our selves in all Philosophical Enquiries. So that knowing what is the
+  form of Inanimate or Mineral bodies, we shall be the better able to
+  proceed in our next Enquiry after the forms of Vegetative   bodies; and last of all, of Animate ones, that seeming to be the highest
+  step of natural knowledge that the mind of man is capable of.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXIV" id="obsXIV">XIV</a>. <i>Of several kindes of frozen </i>Figures<i>.</i></h3>
+
+  <p>I have very often in a Morning, when there has been a great
+  <i>hoar-frost</i>, with an indifferently magnifying <i>Microscope</i>,
+  observ'd the small <i>Stiriæ</i>, or Crystalline beard, which then
+  usually covers the face of most bodies that lie open to the cold air, and
+  found them to be generally <i>Hexangular prismatical</i> bodies, much
+  like the long Crystals of <i>Salt-peter</i>, save onely that the ends of
+  them were differing: for whereas those of <i>Nitre</i> are for the most
+  part <i>pyramidal</i>, being terminated either in a point or edge; these
+  of Frost were hollow, and the cavity in some seem'd pretty deep, and this
+  cavity was the more plainly to be seen, because usually one or other of
+  the six <i>parallelogram</i> sides was wanting, or at least much shorter
+  then the rest.</p>
+
+  <p>But this was onely the Figure of the <i>Bearded hoar-frost</i>; and as
+  for the particles of other kinds of <i>hoar-frosts</i>, they seem'd for
+  the most part irregular, or of no certain Figure. Nay, the parts of those
+  curious branchings, or <i>vortices</i>, that usually in cold weather
+  tarnish the surface of Glass, appear through the <i>Microscope</i> very
+  rude and unshapen, as do most other kinds of frozen <i>Figures</i>, which
+  to the naked eye seem exceeding neat and curious, such as the Figures of
+  <i>Snow</i>, frozen <i>Urine</i>, <i>Hail</i>, several <i>Figures</i>
+  frozen in common Water, <i>&amp;c.</i> Some Observations of each of which
+  I shall hereunto annex, because if well consider'd and examin'd, they
+  may, perhaps, prove very instructive for the finding out of what I have
+  endeavoured in the preceding Observation to shew, to be (next the
+  <i>Globular Figure</i> which is caus'd by <i>congruity</i>, as I hope I
+  have made probable in the sixth <i>Observation</i>) the most simple and
+  plain operation of Nature, of which, notwithstanding we are yet
+  ignorant.</p>
+
+<h3>I.</h3>
+
+<h3><i>Several Observables in the </i>six-branched<i> Figures form'd on the
+surface of Urine by freezing.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-08.png" target="_blank"><i>Schem.</i> 8.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>1 The
+  Figures were all frozen almost even with the surface of the <i>Urine</i>
+  in the Vessel; but the bigger stems were a little <i>prominent</i> above
+  that surface, and the parts of those stems which were nearest the center
+  (<i>a</i>) were biggest above the surface.</p>
+
+  <p>2 I have observ'd several kinds of these Figures, some smaller, no
+  bigger then a Two-pence, others so bigg, that I have by measure found one
+  of its stems or branches above four foot long; and of these, some were
+  pretty round, having all their branches pretty neer alike; other of them
+  were more extended towards one side, as usually those very large ones
+  were, which I have observ'd in Ditches which
+  have been full of foul water.</p>
+
+  <p>3 None of all these Figures I have yet taken notice of, had any
+  regular position in respect of one another, or of the sides of the
+  Vessel; nor did I find any of them equally to exactness extended every
+  way from the center <i>a</i>.</p>
+
+  <p>4 Where ever there was a center, the branchings from it, <i>ab</i>,
+  <i>ac</i>, <i>ad</i>, <i>ae</i>, <i>af</i>, <i>ag</i>, were never fewer,
+  or more then six, which usually concurr'd, or met one another very neer
+  in the same point or center, <i>a</i>; though oftentimes not exactly; and
+  were enclin'd to each other by an angle, of very near sixty degrees, I
+  say, very neer, because, though having endeavoured to measure them the
+  most acurately I was able, with the largest Compasses I had, I could not
+  find any sensible variation from that measure, yet the whole six-branched
+  Figure seeming to compose a solid angle, they must necessarily be
+  somewhat less.</p>
+
+  <p>5 The middle lines or stems of these branches, <i>ab</i>, <i>ac</i>,
+  <i>ad</i>, <i>ae</i>, <i>af</i>, <i>ag,</i> seem'd somewhat whiter, and a
+  little higher then any of the <i>intermediate</i> branchings of these
+  Figures; and the center <i>a</i>, was the most <i>prominent</i> part of
+  the whole Figure, seeming the <i>apex</i> of a solid angle or
+  <i>pyramid</i>, each of the six plains being a little enclin'd below the
+  surface of the <i>Urin</i>.</p>
+
+  <p>6 The lateral branchings issuing out of the great ones, such as
+  <i>op</i>, <i>mq</i>, &amp;c. were each of them inclin'd to the great
+  ones, by the same angle of about sixty degrees, as the great ones were
+  one to another, and always the bigger branchings were <i>prominent</i>
+  above the less, and the less above the least, by proportionate
+  <i>gradations</i>.</p>
+
+  <p>7 The <i>lateral</i> branches shooting out of the great ones, went all
+  of them from the center, and each of them was parallel to that great
+  branch, next to which it lay; so that as all the branches on one side
+  were parallel to one another, so were they all of them to the
+  <i>approximate</i> great branch, as <i>po</i>, <i>qr</i>, as they were
+  parallel to each other, and shot from the center, so were they parallel
+  also to the great branch <i>ab</i>.</p>
+
+  <p>8 Some of the stems of the six branches proceeded straight, and of a
+  thickness that gradually grew sharper towards the end, as <i>ag</i>.</p>
+
+  <p>9 Others of the stems of those branches grew bigger and knotty towards
+  the middle, and the branches also as well as stems, from Cylinders grew
+  into Plates, in a most admirable and curious order, so exceeding regular
+  and delicate, as nothing could be more, as is visible in <i>ab</i>,
+  <i>ac</i>, <i>ad</i>, <i>ae</i>, <i>af</i>, but towards the end of some
+  of these stems, they began again to grow smaller and to recover their
+  former branchings, as about <i>k</i> and <i>n</i>.</p>
+
+  <p>10 Many of the <i>lateral</i> branches had <i>collateral</i> branches
+  (if I may so call them) as <i>qm</i> had many such as <i>st</i>, and most
+  of those again <i>subcollateral</i>, as <i>vw</i>, and these again had
+  others less, which one may call <i>laterosubcollateral</i>, and these
+  again others, and they others, <i>&amp;c.</i> in greater Figures.</p>
+
+  <p>11 The branchings of the main Stems joyn'd not together by any regular
+  line, nor did one side of the one lie over the other side of the other,
+  but the small <i>collateral</i> and <i>subcollateral</i> branches did lie
+  at top of one another according to a certain order or
+  method, which I always observ'd to be this.</p>
+
+  <p>12 That side of a <i>collateral</i> or <i>subcollateral</i>, &amp;c.
+  branch, lay over the side of the <i>approximate</i> (as the feathers in
+  the wing of a Bird) whose branchings proceeded parallel to the last
+  biggest stem from which it sprung, and not to the biggest stem of all,
+  unless that were a second stem backwards.</p>
+
+  <p>13 This rule that held in the branchings of the <i>Sexangular
+  Figure</i> held also in the branchings of any other great or small stem,
+  though it did not proceed from a center.</p>
+
+  <p>14 The exactness and curiosity of the figuration of these branches,
+  was in every particular so transcendent, that I judge it almost
+  impossible for humane art to imitate.</p>
+
+  <p>15 Tasting several cleer pieces of this <i>Ice</i>, I could not find
+  any <i>Urinous</i> taste in them, but those few I tasted, seem'd as
+  <i>insipid</i> as water.</p>
+
+  <p>16 A figuration somewhat like this, though indeed in some particulars
+  much more curious, I have several times observ'd in <i>regulus martis
+  stellatus</i>, but with this difference, that all the stems and
+  branchings are bended in a most excellent and regular order, whereas in
+  <i>Ice</i> the stems and branchings are streight, but in all other
+  particulars it agrees with this, and seems indeed nothing but one of
+  these stars, or branched Figures frozen on <i>Urine</i>, distorted, or
+  wreathed a little, with a certain proportion: <i>Lead</i> also that has
+  <i>Arsenick</i> and some other things mixt with it, I have found to have
+  its surface, when suffer'd to cool, figured somewhat like the branchings
+  of <i>Urine</i>, but much smaller.</p>
+
+  <p>17 But there is a <i>Vegetable</i> which does exceedingly imitate
+  these branches, and that is, <i>Fearn</i>, where the main stem may be
+  observ'd to shoot out branches, and the stems of each of these
+  <i>lateral</i> branches, to send forth <i>collateral</i>, and those
+  <i>subcollateral</i> and those <i>laterosubcollateral,</i> &amp;c. and
+  all those much after the same order with the branchings, divisions, and
+  subdivisions in the branchings of these Figures in frozen <i>Urine</i>;
+  so that if the Figures of both be well consider'd, one would ghess that
+  there were not much greater need of a <i>seminal principle</i> for the
+  production of <i>Fearn</i>, then for the production of the branches of
+  <i>Urine</i>, or the <i>Stella martis</i>, there seeming to be as much
+  form and beauty in the one as in the other.</p>
+
+  <p>And indeed, this Plant of <i>Fearn</i>, if all particulars be well
+  consider'd, will seem of as simple, and uncompounded a form as any
+  <i>Vegetable</i>, next to <i>Mould</i> or <i>Mushromes</i>, and would
+  next after the invention of the forms of those, deserve to be enquir'd
+  into; for notwithstanding several have affirm'd it to have seed, and to
+  be propagated thereby; yet, though I have made very diligent enquiry
+  after that particular, I cannot find that there is any part of it that
+  can be imagin'd to be more seminal then another: But this onely here by
+  the by:</p>
+
+  <p>For the freezing Figures in <i>Urine</i>, I found it requisite,</p>
+
+  <p>First, that the Superficies be not disturbed with any wind, or other
+  commotion of the air, or the like.</p>
+
+  <p>Secondly, that it be not too long exposed, so as that the whole bulk
+  be frozen, for oftentimes, in such cases, by reason of the swelling the
+  of <i>Ice</i>, or from some other cause, the curious branched Figures
+  disappear.</p>
+
+  <p>Thirdly, an artificial freezing with <i>Snow</i> and <i>Salt</i>,
+  apply'd to the outside of the containing Vessel, succeeds not well,
+  unless there be a very little quantity in the Vessel.</p>
+
+  <p>Fourthly, If you take any cleer and smooth Glass, and wetting all the
+  inside of it with <i>Urine</i>, you expose it to a very sharp freezing,
+  you will find it cover'd with a very regular and curious Figure.</p>
+
+<h3>II</h3>.
+
+<h3><i>Observables in figur'd </i>Snow<i>.</i></h3>
+
+  <p>Exposing a piece of black Cloth, or a black Hatt to the falling
+  <i>Snow</i>, I have often with great pleasure, observ'd such an infinite
+  variety of curiously figur'd <i>Snow</i>, that it would be as impossible
+  to draw the Figure and shape of every one of them, as to imitate exactly
+  the curious and Geometrical <i>Mechanisme</i> of Nature in any one. Some
+  coorse draughts, such as the coldness of the weather, and the ill
+  provisions, I had by me for such a purpose, would permit me to make, I
+<span class="sidenote">
+<a href="images/scheme-08.png" target="_blank"><i>Schem.</i> 8.</a><br /><i>Fig.</i> 2.
+</span>
+  have here added in the Second <i>Figure</i> of the Eighth
+  <i>Scheme</i>.</p>
+
+  <p>In all which I observ'd, that if they were of any regular Figures,
+  they were always branched out with six principal branches, all of equal
+  length, shape and make, from the center, being each of them inclin'd to
+  either of the next branches on either side of it, by an angle of sixty
+  degrees.</p>
+
+  <p>Now, as all these stems were for the most part in one flake exactly of
+  the same make, so were they in differing Figures of very differing ones;
+  so that in a very little time I have observ'd above an hundred several
+  cizes and shapes of these starry flakes.</p>
+
+  <p>The branches also out of each stem of any one of these flakes, were
+  exactly alike in the same flake; so that of whatever Figure one of the
+  branches were, the other five were sure to be of the same, very exactly,
+  that is, if the branchings of the one were small <i>Perallelipipeds</i>
+  or Plates, the branchings of the other five were of the same; and
+  generally, the branchings were very conformable to the rules and method
+  observ'd before, in the Figures on <i>Urine</i>, that is, the branchings
+  from each side of the stems were parallel to the next stem on that side,
+  and if the stems were plated, the branches also were the same; if the
+  stems were very long, the branches also were so, <i>&amp;c.</i></p>
+
+  <p>Observing some of these figur'd flakes with a <i>Microscope</i>, I
+  found them not to appear so curious and exactly figur'd as one would have
+  imagin'd, but like Artificial Figures, the bigger they were magnify'd,
+  the more irregularites appear'd in them; but this irregularity seem'd
+  ascribable to the thawing and breaking of the flake by the fall, and not
+  at all to the defect of the <i>plastick</i> virtue of Nature, whose
+  curiosity in the formation of most of these kind of regular Figures, such
+  as those of <i>Salt</i>, <i>Minerals</i>, &amp;c. appears by
+  the help of the <i>Microscope</i>, to be very many degrees smaller then
+  the most acute eye is able to perceive without it. And though one of
+  these six-branched Stars appear'd here below much of the shape described
+<span class="sidenote">
+<a href="images/scheme-08.png" target="_blank"><i>Schem.</i> 8.</a><br /><i>Fig.</i> 3.
+</span>
+  in the Third <i>Figure</i> of the Eighth <i>Scheme</i>; yet I am very apt
+  to think, that could we have a sight of one of them through a
+  <i>Microscope</i> as they are generated in the Clouds before their
+  Figures are vitiated by external accidents, they would exhibit abundance
+  of curiosity and neatness there also, though never so much magnify'd: For
+  since I have observ'd the Figures of <i>Salts</i> and <i>Minerals</i> to
+  be some of them so exceeding small, that I have scarcely been able to
+  perceive them with the <i>Microscope</i>, and yet have they been regular,
+  and since (as far as I have yet examin'd it) there seems to be but one
+  and the same cause that produces both these effects, I think it not
+  irrational to suppose that these pretty figur'd Stars of <i>Snow</i>,
+  when at first generated might be also very regular and exact.</p>
+
+<h3>III.</h3>
+
+<h3><i>Several kinds of Figures in </i>Water<i> frozen.</i></h3>
+
+  <p>Putting fair Water into a large capacious Vessel of <i>Glass</i>, and
+  exposing it to the cold, I observ'd after a little time, several broad,
+  flat, and thin <i>laminæ</i>, or plates of <i>Ice</i>, crossing the bulk
+  of the water and one another very irregularly, onely most of them seem'd
+  to turn one of their edges towards that side of the Glass which was next
+  it, and seem'd to grow, as 'twere from the inside of the Vessel inwards
+  towards the middle, almost like so many blades of <i>Fern</i>. Having
+  taken several of these plates out of water on the blade of a Knife, I
+  observ'd them figur'd much after the manner of <i>Herring bones</i>, or
+  <i>Fern blades</i>, that is, there was one bigger stem in the middle like
+  the back-bone, and out of it, on either side, were a multitude of small
+  <i>stiriæ</i>, or <i>icicles</i>, like the smaller bones, or the smaller
+  branches in <i>Fern</i>, each of these branches on the one side, were
+  parallel to all the rest on the same side, and all of them seem'd to make
+  an angle with the stem, towards the top, of sixty degrees, and towards
+  the bottom or root of this stem, of 120. See the fourth <i>Figure</i> of
+  the 8. <i>Plate</i>.</p>
+
+  <p>I observ'd likewise several very pretty Varieties of Figures in Water,
+  frozen on the top of a broad flat Marble-stone, expos'd to the cold with
+  a little Water on it, some like feathers, some of other shapes, many of
+<span class="sidenote">
+<a href="images/scheme-08.png" target="_blank"><i>Schem.</i> 8.</a><br /><i>Fig.</i> 5.
+</span>
+  them were very much of the shape exprest in the fifth Figure of the 8.
+  <i>Scheme</i>, which is extremely differing from any of the other
+  Figures.</p>
+
+  <p>I observ'd likewise, that the shootings of <i>Ice</i> on the top of
+  Water, beginning to freez, were in streight <i>prismatical</i> bodies
+  much like those of <i>roch-peter</i>, that they crost each other usually
+  without any kind of order or rule, that they were always a little higher
+  then the surface of the Water that lay between them; that by degrees
+  those <i>interjacent</i> spaces would be fill'd with <i>Ice</i> also,
+  which usually would be as high as the surface of the rest.</p>
+
+  <p>In flakes of <i>Ice</i> that had been frozen on the top of Water to
+  any considerable thickness, I observ'd that both the upper and
+  the under sides of it were curiously quill'd, furrow'd, or grain'd, as it
+  were, which when the Sun shone on the Plate, was exceeding easily to be
+<span class="sidenote">
+<a href="images/scheme-08.png" target="_blank"><i>Schem.</i> 8.</a><br /><i>Fig.</i> 6.
+</span>
+  perceiv'd to be much after the shape of the lines in the 6. <i>Figure</i>
+  of the 8. <i>Scheme</i>, that is, they consisted of several streight ends
+  of parallel Plates, which were of divers lengths and angles to one
+  another without any certain order.</p>
+
+  <p>The cause of all which regular Figures (and of hundreds of others,
+  namely of <i>Salts</i>, <i>Minerals</i>, <i>Metals,</i> &amp;c. which I
+  could have here inserted, would it not have been too long) seems to be
+  deducible from the same Principles, which I have (in the 13.
+  <i>Observation</i>) hinted only, having not yet had time to compleat a
+  <i>Theory</i> of them. But indeed (which I there also hinted) I judge it
+  the second step by which the <i>Pyramid</i> of natural knowledge (which
+  is the knowledge of the form of bodies) is to be ascended: And whosoever
+  will climb it, must be well furnish'd with that which the Noble
+  <i>Verulam</i> calls <i>Scalam Intellectus</i>; he must have scaling
+  Ladders, otherwise the steps are so large and high, there will be no
+  getting up them, and consequently little hopes of attaining any higher
+  station, such as to the knowledge of the most simple principle of
+  Vegetation manifested in Mould and Mushromes, which, as I elsewhere
+  endeavoured to shew, seems to be the third step; for it seems to me, that
+  the Intellect of man is like his body, destitute of wings, and cannot
+  move from a lower to a higher and more sublime station of knowledg,
+  otherwise then step by step, nay even there where the way is prepar'd and
+  already made passible; as in the <i>Elements of Geometry</i>, or the
+  like, where it is fain to climb a whole <i>series</i> of Propositions by
+  degrees, before it attains the knowledge of one <i>Probleme</i>. But if
+  the ascent be high, difficult and above its reach, it must have recourse
+  to a <i>novum organum</i>, some new engine and contrivance, some new kind
+  of <i>Algebra</i>, or <i>Analytick Art</i> before it can surmount it.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXV" id="obsXV">XV</a>. <i>Of </i>Kettering-stone<i>, and of the pores of </i>Inanimate<i>
+bodies.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-09.png" target="_blank"><i>Schem.</i> 9.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>This Stone which is brought from <i>Kettering</i> in <i>Northampton-Shire</i>,
+  and digg'd out of a Quarry, as I am inform'd, has a grain altogether
+  admirable, nor have I ever seen or heard of any other stone that has the
+  like. It is made up of an innumerable company of small bodies, not all of
+  the same cize or shape, but for the most part, not much differing from a
+  Globular form, nor exceed they one another in Diameter above three or
+  four times; they appear to the eye, like the Cobb or Ovary of a
+  <i>Herring</i>, or some smaller fishes, but for the most part, the
+  particles seem somewhat less, and not so uniform; but their variation
+  from a perfect globular ball, seems to be only by the pressure of the
+  <i>contiguous</i> bals which have a little deprest and protruded those
+  toucht sides inward, and forc'd the other sides as much
+  outwards beyond the limits of a Globe; just as it would happen, if a heap
+  of exactly round Balls of soft Clay were heaped upon one another; or, as
+  I have often seen a heap of small Globules of <i>Quicksilver</i>, reduc'd
+  to that form by rubbing it much in a glaz'd Vessel, with some slimy or
+  sluggish liquor, such as Spittle, when though the top of the upper
+  Globules be very neer spherical, yet those that are prest upon by others,
+  exactly imitate the forms of these lately mention'd grains.</p>
+
+  <p>Where these grains touch each other, they are so firmly united or
+  settled together, that they seldom part without breaking a hole in one or
+  th'other of them, such as <i>a</i>, <i>a</i>, <i>a</i>, <i>b</i>,
+  <i>c</i>, <i>c</i>, &amp;c. Some of which fractions, as <i>a</i>,
+  <i>a</i>, <i>a</i>, <i>a</i>, where the touch has been but light, break
+  no more then the outward crust, or first shell of the stone, which is of
+  a white colour, a little dash'd with a brownish Yellow, and is very thin,
+  like the shell of an Egg: and I have seen some of those grains perfectly
+  resemble some kind of Eggs, both in colour and shape: But where the union
+  of the <i>contiguous granules</i> has been more firm, there the divulsion
+  has made a greater Chasm, as at <i>b</i>, <i>b</i>, <i>b</i>, in so much
+  that I have observ'd some of them quite broken in two, as at <i>c</i>,
+  <i>c</i>, <i>c</i>, which has discovered to me a further resemblance they
+  have to Eggs, they having an appearance of a white and yelk, by two
+  differing substances that envelope and encompass each other.</p>
+
+  <p>That which we may call the white was pretty whitish neer the yelk, but
+  more duskie towards the shell; some of them I could plainly perceive to
+  be shot or radiated like a <i>Pyrites</i> or <i>fire-stone</i>; the yelk
+  in some I saw hollow, in others fill'd with a duskie brown and porous
+  substance like a kind of pith.</p>
+
+  <p>The small pores, or <i>interstitia</i> <i>eeee</i> betwixt the
+  Globules, I plainly saw, and found by other trials to be every way
+  pervious to air and water, for I could blow through a piece of this stone
+  of a considerable thickness, as easily as I have blown through a Cane,
+  which minded me of the pores which <i>Des Cartes</i> allow his <i>materia
+  subtilis</i> between the <i>æthereal</i> globules.</p>
+
+  <p>The object, through the <i>Microscope</i>, appears like a
+  <i>Congeries</i> or heap of Pibbles, such as I have often seen cast up on
+  the shore, by the working of the Sea after a great storm, or like (in
+  shape, though not colour) a company of small Globules of Quicksilver,
+  look'd on with a <i>Microscope</i>, when reduc'd into that form by the
+  way lately mentioned. And perhaps, this last may give some hint at the
+  manner of the formation of the former: For supposing some
+  <i>Lapidescent</i> substance to be generated, or some way brought (either
+  by some commixture of bodies in the Sea it self, or protruded in,
+  perhaps, out of some <i>subterraneous</i> caverns) to the bottom of the
+  Sea, and there remaining in the form of a liquor like Quicksilver,
+  <i>heterogeneous</i> to the ambient <i>Saline</i> fluid, it may by the
+  working and tumblings of the Sea to and fro be jumbled and comminuted
+  into such Globules as may afterwards be hardned into Flints, the lying of
+  which one upon another, when in the Sea, being not very hard, by reason
+  of the weight of the incompassing fluid, may cause the undermost to be a
+  little, though not much, varied from a globular Figure. But this only by
+  the by.</p>
+
+  <p>After what manner this <i>Kettering-stone</i> should be generated I
+  cannot learn, having never been there to view the place, and observe the
+  circumstances; but it seems to me from the structure of it to be
+  generated from some substance once more fluid, and afterwards by degrees
+  growing harder, almost after the same manner as I supposed the generation
+  of Flints to be made.</p>
+
+  <p>But whatever were the cause of its curious texture, we may learn this
+  information from it; that even in those things which we account vile,
+  rude, and coorse, Nature has not been wanting to shew abundance of
+  curiosity and excellent Mechanisme.</p>
+
+  <p>We may here find a Stone by help of a <i>Microscope</i>, to be made up
+  of abundance of small Balls, which do but just touch each other, and yet
+  there being so many contacts, they make a firm hard mass, or a Stone much
+  harder then Free-stone.</p>
+
+  <p>Next, though we can by a <i>Microscope</i> discern so curious a shape
+  in the particles, yet to the naked eye there scarce appears any such
+  thing; which may afford us a good argument to think, that even in those
+  bodies also, whose <i>texture</i> we are not able to discern, though
+  help'd with <i>Microscopes</i>, there may be yet <i>latent</i> so curious
+  a <i>Schematisme</i>, that it may abundantly satisfie the curious
+  searcher, who shall be so happy as to find some way to discover it.</p>
+
+  <p>Next, we here find a Stone, though to the naked eye a very close one,
+  yet every way perforated with innumerable pores, which are nothing else
+  but the <i>interstitia</i>, between those multitudes of minute globular
+  particles, that compose the bulk it self, and these pores are not only
+  discover'd by the <i>Microscope</i>, but by this contrivance.</p>
+
+  <p>I took a pretty large piece of this stone, and covering it all over
+  with cement, save only at two opposite parts, I found my self able, by
+  blowing in at one end that was left open, to blow my spittle, with which
+  I had wet the other end, into abundance of bubbles, which argued these
+  pores to be open and pervious through the whole stone, which affords us a
+  very pretty instance of the porousness of some seemingly close bodies, of
+  which kind I shall anon have occasion to subjoyn many more, tending to
+  prove the same thing.</p>
+
+  <p>I must not here omit to take notice, that in this body there is not a
+  <i>vegetative</i> faculty that should so contrive this structure for any
+  peculiar use of <i>vegetation</i> or growth, whereas in the other
+  instances of vegetable porous bodies, there is an <i>anima</i> or
+  <i>forma informans</i>, that does contrive all the Structures and
+  <i>Mechanismes</i> of the constituting body, to make them subservient and
+  usefull to the great Work or Function they are to perform. And so I ghess
+  the pores in Wood, and other vegetables, in bones, and other Animal
+  substances, to be as so many channels, provided by the Great and Alwise
+  Creator, for the conveyance of appropriated juyces to particular parts.
+  And therefore, that this may tend, or be pervious all towards one part,
+  and may have impediments, as valves or the like, to any other; but in
+  this body we have very little reason so suspect there should be any such
+  design, for it is equally pervious every way, not onely forward,
+  but backwards, and side-ways, and seems
+  indeed much rather to be <i>Homogeneous</i> or similar to those pores,
+  which we may with great probability believe to be the channels of
+  <i>pellucid</i> bodies, not directed, or more open any one way, then any
+  other, being equally pervious every way. And, according as these pores
+  are more or greater in respect of the <i>interstitial</i> bodies, the
+  more transparent are the so constituted concretes; and the smaller those
+  pores are, the weaker is the <i>Impulse</i> of light communicated through
+  them, though the more quick be the progress.</p>
+
+  <p>Upon this Occasion, I hope it will not be altogether unseasonable, if
+  I propound my conjectures and <i>Hypothesis</i> about the <i>medium</i>
+  and conveyance of light.</p>
+
+  <p>I suppose then, that the greatest part of the <i>Interstitia</i> of
+  the world, that lies between the bodies of the Sun and Starrs, and the
+  Planets, and the Earth, to be an exceeding fluid body, very apt and ready
+  to be mov'd, and to communicate the motion of any one part to any other
+  part, though never so far distant: Nor do I much concern my self, to
+  determine what the Figure of the particles of this exceedingly subtile
+  fluid <i>medium</i> must be, nor whether it have any interstitiated pores
+  or vacuities, it being sufficient to solve all the <i>Phænomena</i> to
+  suppose it an exceedingly fluid, or the most fluid body in the world, and
+  as yet impossible to determine the other difficulties.</p>
+
+  <p>That being so exceeding fluid a body, it easily gives passage to all
+  other bodies to move to and fro in it.</p>
+
+  <p>That it neither receives from any of its parts, or from other bodies;
+  nor communicates to any of its parts, or to any other body, any impulse,
+  or motion in a direct line, that is not of a determinate quickness. And
+  that when the motion is of such determinate swiftness, it both receives,
+  and communicates, or propagates an impulse or motion to any imaginable
+  distance in streight lines, with an unimaginable celerity and vigour.</p>
+
+  <p>That all kind of solid bodies consist of pretty massie particles in
+  respect of the particles of this fluid <i>medium</i>, which in many
+  places do so touch each other, that none of this fluid <i>medium</i>
+  interposes much after the same mannner (to use a gross similitude) as a
+  heap of great stones compose one great <i>congeries</i> or mass in the
+  midst of the water.</p>
+
+  <p>That all fluid bodies which we may call <i>tangible</i>, are nothing
+  but some more subtile parts of those particles, that serve to constitute
+  all <i>tangible</i> bodies.</p>
+
+  <p>That the water, and such other fluid bodies, are nothing but a
+  <i>congeries</i> of particles agitated or made fluid by it in the same
+  manner as the particles of <i>Salt</i> are agitated or made fluid by a
+  parcel of water, in which they are dissolv'd, and subsiding to the bottom
+  of it, constitute a fluid body, much more massie and dense, and less
+  fluid then the pure water it self.</p>
+
+  <p>That the air on the other side is a certain company of particles of
+  quite another kind, that is, such as are very much smaller, and more
+  easiely moveable by the motion of this fluid <i>medium</i>; much like
+  those very subtile parts of <i>Cochenel</i>, other very deep tinging
+  bodies, where by a very small parcel of matter is able
+  to tinge and diffuse it self over a very great quantity of the fluid
+  dissolvent; or somewhat after that manner, as smoak, and such like minute
+  bodies, or steams, are observ'd to tinge a very great quantity of air;
+  onely this last similitude is deficient in one propriety, and that is a
+  perpetuity or continuance in that state of commixture with the air, but
+  the former does more neerly approach to the nature and manner of the
+  air's being dissolv'd by this fluid or <i>Æther</i>. And this Similitude
+  will further hold in these proprieties; that as those tinctures may be
+  increased by certain bodies, so may they be precipitated by others, as I
+  shall afterwards shew it to be very probable, that the like accidents
+  happen even to the Air it self.</p>
+
+  <p>Further, as these solutions and tinctures do alter the nature of these
+  fluid bodies, as to their aptness to propagate a motion or impulse
+  through them, even so does the particles of the Air, Water, and other
+  fluid bodies, and of Glass, Crystal, <i>&amp;c.</i> which are commixt
+  with this bulk of the <i>Æther</i> alter the motion of the propagated
+  pulse of light; that is, where these more bulkie particles are more
+  plentifull, and consequently a lesser quantity of the <i>Æther</i>
+  between them to be mov'd, there the motion must necessarily be the
+  swifter, though not so robust, which will produce those effects, which I
+  have (I hope) with some probability, ascribed to it in the digression
+  about Colours, at the end of the <i>Observations</i> on
+  <i>Muscovy-glass.</i></p>
+
+  <p>Now, that other Stones, and those which have the closest and hardest
+  textures, and seem (as far as we are able to discover with our eyes,
+  though help'd with the best <i>Microscopes</i>) freest from pores, are
+  yet notwithstanding replenish'd with them, an Instance or two will, I
+  suppose, make more probable.</p>
+
+  <p>A very solid and unflaw'd piece of cleer white <i>Marble</i>, if it be
+  well polish'd and glaz'd, has so curiously smooth a surface, that the
+  best and most polish'd surface of any wrought-glass, seems not to the
+  naked eye, nor through a <i>Microscope</i>, to be more smooth, and less
+  porous. And yet, that this hard close body is replenish'd with abundance
+  of pores, I think these following Experiments will sufficiently
+  prove.</p>
+
+  <p>The first is, That if you take such a piece, and for a pretty while
+  boyl it in Turpentine and Oyl of Turpentine, you shall find that the
+  stone will be all imbu'd with it; and whereas before it look'd more
+  white, but more opacous, now it will look more greasie, but be much more
+  transparent, and if you let it lie but a little while, and then break off
+  a part of it, you shall find the unctuous body to have penetrated it to
+  such a determinate depth every way within the surface. This may be yet
+  easier try'd with a piece of the same <i>Marble</i>, a little warm'd in
+  the fire, and then a little Pitch or Tarr melted on the top of it; for
+  these black bodies, by their insinuating themselves into the invisible
+  pores of the stone, ting it with so black a hue, that there can be no
+  further doubt of the truth of this assertion, that it abounds with small
+  imperceptible pores.</p>
+
+  <p>Now, that other bodies will also sink into the pores of <i>Marble</i>,
+  besides unctuous, I have try'd, and found, that a very Blue tincture made
+  in <i>spirit of Urine</i> would very readily and
+  easily sink into it, as would also several tinctures drawn with <i>spirit
+  of Wine</i>.</p>
+
+  <p>Nor is <i>Marble</i> the only seemingly close stone, which by other
+  kinds of Experiments may be found porous; for I have by this kind of
+  Experiment on divers other stones found much the same effect, and in
+  some, indeed much more notable. Other stones I have found so porous, that
+  with the <i>Microscope</i> I could perceive several small winding holes,
+  much like Worm-holes, as I have noted in some kind of
+  <i>Purbeck-stone</i>, by looking on the surface of a piece newly flaw'd
+  off, for if otherwise, the surface has been long expos'd to the Air, or
+  has been scraped with any tool, those small caverns are fill'd with dust,
+  and disappear.</p>
+
+  <p>And to confirm this <i>Conjecture</i>, yet further, I shall here
+  insert an excellent account, given into the <i>Royal Society</i> by that
+  Eminently Learned Physician, Doctor <i>Goddard</i>, of an Experiment, not
+  less instructive then curious and accurate, made by himself on a very
+  hard and seemingly close stone call'd <i>Oculus Mundi</i>, as I find it
+  preserv'd in the Records of that Honourable Society.</p>
+
+<blockquote>
+  <p>A small stone of the kind, call'd by some Authours, <i>Oculus
+  Mundi</i>, being dry and cloudy, weigh'd 5-209/256 <i>Grains</i>.</p>
+
+  <p>The same put under water for a night, and somewhat more, became
+  transparent, and the superficies being wiped dry, weighed 6-3/256
+  <i>Grains</i>.</p>
+
+  <p>The difference between these two weights, 0-50/256 of a
+  <i>Grain</i>.</p>
+
+  <p>The same Stone kept out of water one Day and becoming cloudy again
+  weighed, 5-225/256 <i>Graines</i>.</p>
+
+  <p>Which was more then the first weight, 0-16/256 of a <i>Grain</i>.</p>
+
+  <p>The same being kept two Days longer weighed, 5-202/256
+  <i>Graines</i>.</p>
+
+  <p>Which was less then at first, 0-7/256 a <i>Grain</i>.</p>
+
+  <p>Being kept dry something longer it did not grow sensibly lighter.</p>
+
+  <p>Being put under water for a night and becoming again transparent and
+  wiped dry, the weight was, <i>6-3/256 Grains</i>, the same with the first
+  after putting in water, and more then the last weight after keeping of it
+  dry, 0-57/256 of a <i>Grain</i>.</p>
+
+  <p>Another Stone of the same kind being variegated with milky
+  <i>white</i> and <i>gray</i> like some sorts of <i>Agates</i>, while it
+  lay under water, was alwaies invironed with little Bubbles, such as
+  appear in water a little before boyling, next the sides
+  of the Vessel.</p>
+
+  <p>There were also some the like Bubbles on the Surface of the water just
+  over it, as if either some exhalations came out of it, or that it did
+  excite some fermentation in the parts of the water contiguous to it.</p>
+
+  <p>There was little sensible difference in the transparency of this
+  Stone, before the putting under water, and after: To be sure the
+  milky-<i>white</i> parts continued as before, but more difference in
+  weight then in the former. For whereas before the putting into the water
+  the weight was 18-97/128 <i>Graines</i>. After it had lyen in about four
+  and twenty hours the weight was 20-27/128 <i>Graines</i>, so the
+  difference was, 1-58/128 <i>Graines</i>.</p>
+
+  <p>The same Stone was infused in the water scalding hot, and so continued
+  for a while after it was cold, but got no more weight then upon infusing
+  in the cold, neither was there any sensible Difference in the weight both
+  times.</p>
+
+</blockquote>
+
+  <p>In which Experiment, there are three Observables that seem very
+  manifestly to prove the porousness of these seemingly close bodies: the
+  first is their acquiring a transparency, and losing their whiteness after
+  steeping in water, which will seem the more strongly to argue it, if what
+  I have already said about the making transparent, or clarifying of some
+  bodies, as the white powder of beaten Glass, and the froth of some
+  glutinous transparent liquor be well consider'd; for thereby it will seem
+  rational to think that this transparency arises from the insinuation of
+  the water (which has much the same refraction with such stony particles,
+  as may be discover'd by Sand view'd with a <i>Microscope</i>) into those
+  pores which were formerly repleat with air (that has a very differing
+  refraction, and consequently is very reflective) which seems to be
+  confirm'd by the second Observable, namely, the increase of weight after
+  keeping, and decrease upon drying. And thirdly, seem'd yet more sensibly
+  confirm'd by the multitude of bubbles in the last Experiment.</p>
+
+  <p>We find also most Acid Salts very readily to dissolve and separate the
+  parts of this body one from another; which is yet a further Argument to
+  confirm the porousness of bodies, and will serve as such, to shew that
+  even Glass also has an abundance of pores in it, since there are several
+  liquors, that with long staying in a Glass, will so <i>Corrode</i> and
+  eat into it, as at last, to make it pervious to the liquor it contain'd,
+  of which I have seen very many Instances.</p>
+
+  <p>Since therefore we find by other proofs, that many of those bodies
+  which we think the most solid ones, and
+  appear so to our sight, have notwithstanding abundance of those grosser
+  kind of pores, which will admit several kinds of liquors into them, why
+  should we not believe that Glass, and all other transparent bodies abound
+  with them, since we have many other arguments, besides the propagation of
+  light, which seem to argue for it?</p>
+
+  <p>And whereas it may be objected, that the propagation of light is no
+  argument that there are those atomical pores in glass, since there are
+  <i>Hypotheses</i> plausible enough to solve those <i>Phænomena</i>, by
+  supposing the pulse onely to be communicated through the transparent
+  body.</p>
+
+  <p>To this I answer, that that <i>Hypothesis</i> which the industrious
+  <i>Mersennus</i> has publish'd about the slower motion of the end of a
+  Ray in a denser <i>medium</i>, then in a more rare and thin, seems
+  altogether unsufficient to solve abundance of <i>Phænomena</i>, of which
+  this is not the least considerable, that it is impossible from that
+  supposition, that any colours should be generated from the refraction of
+  the Rays; for since by that <i>Hypothesis</i> the <i>undulating pulse</i>
+  is always carried perpendicular, or at right angles with the Ray or Line
+  of direction, it follows, that the stroke of the pulse of light, after it
+  has been once or twice refracted (through a Prisme, for example) must
+  affect the eye with the same kind of stroke as if it had not been
+  refracted at all. Nor will it be enough for a Defendant of that
+  <i>Hypothesis</i>, to say, that perhaps it is because the refractions
+  have made the Rays more weak, for if so, then two refractions in the two
+  parallel sides of a <i>Quadrangular Prisme</i> would produce colours, but
+  we have no such <i>Phænomena</i> produc'd.</p>
+
+  <p>There are several Arguments that I could bring to evince that there
+  are in all transparent bodies such atomical pores. And that there is such
+  a fluid body as I am arguing for, which is the <i>medium</i>, or
+  Instrument, by which the pulse of Light is convey'd from the <i>lucid
+  body</i> to the enlightn'd. But that it being a digression from the
+  Observations I was recording, about the Pores of <i>Kettering Stone</i>,
+  it would be too much such, if I should protract it too long; and
+  therefore I shall proceed to the next <i>Observation</i>.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXVI" id="obsXVI">XVI</a>. <i>Of </i>Charcoal<i>, or burnt </i>Vegetables<i>.</i></h3>
+
+  <p>Charcoal, or a Vegetable burnt black, affords an object no less
+  pleasant than instructive, for if you take a small round Charcoal, and
+  break it short with your fingers, you may perceive it to break with a
+  very smooth and sleek surface, almost like the surface of black sealing
+  Wax; this surface, if it be look'd on with an ordinary <i>Microscope</i>,
+  does manifest abundance of those pores which are also visible to the eye
+  in many kinds of <i>Wood</i>, rang'd round the pith, both a in kind of
+  circular order, and a radiant one. Of these there are a multitude in the
+  substance of the Coal, every where almost perforating and drilling it
+  from end to end; by means of which, be the Coal
+  never so long, you may easily blow through it; and this you may presently
+  find, by wetting one end of it with Spittle, and blowing at the
+  other.</p>
+
+  <p>But this is not all, for besides those many great and conspicuous
+  irregular spots or pores, if a better <i>Microscope</i> be made use of,
+  there will appear an infinite company of exceedingly small, and very
+  regular pores, so thick and so orderly set, and so close to one another,
+  that they leave very little room or space between them to be fill'd with
+  a solid body, for the apparent <i>interstitia</i> or separating sides of
+  these pores seem so thin in some places, that the texture of a Honey-comb
+  cannot be more porous. Though this be not every where so, the
+  intercurrent partitions in some places being very much thicker in
+  proportion to the holes.</p>
+
+  <p>Most of these small pores seem'd to be pretty round, and were rang'd
+  in rows that radiated from the pith to the bark; they all of them seem'd
+  to be continued open pores, running the whole length of the Stick; and
+  that they were all perforated, I try'd by breaking off a very thin sliver
+  of the Coal cross-ways, and then with my <i>Microscope</i>, diligently
+  surveying them against the light, for by that means I was able to see
+  quite through them.</p>
+
+  <p>These pores were so exceeding small and thick, that in a line of them,
+  1/18 part of an Inch long, I found by numbring them no less then 150.
+  small pores; and therefore in a line of them an Inch long, must be no
+  less then 2700. pores, and in a circular <i>area</i> of an Inch diameter,
+  must be about 5725350. of the like pores; so that a Stick of an Inch
+  Diameter, may containe no less then seven hundred and twenty five
+  thousand, besides 5 Millions of pores, which would, I doubt not, seem
+  even incredible, were not every one left to believe his own eyes. Nay,
+  having since examin'd <i>Cocus, black and green Ebony, Lignum Vitæ</i>,
+  &amp;c. I found, that all these Woods have their pores, abundantly
+  smaller then those of soft light Wood; in so much, that those of
+  <i>Guajacum</i> seem'd not above an eighth part of the bigness of the
+  pores of Beech, but then the <i>Interstitia</i> were thicker; so
+  prodigiously curious are the contrivances, pipes, or sluces by which the
+  <i>Succus nutritius</i>, or Juyce of a Vegetable is convey'd from place
+  to place.</p>
+
+  <p>This <i>Observation</i> seems to afford us the true reason of several
+  <i>Phænomena</i> of Coals; as</p>
+
+  <p>First, why they look black; and for this we need go no further then
+  the <i>Scheme</i>, for certainly, a body that has so many pores in it as
+  this is discover'd to have, from each of which no light is reflected,
+  must necessarily look black, especially, when the pores are somewhat
+  bigger in proportion to the intervals then they are cut in the
+  <i>Scheme</i>, black being nothing else but a privation of Light, or a
+  want of reflection; and wheresover this reflecting quality is deficient,
+  there does that part look black, whether it be from a porousness of the
+  body, as in this Instance, or in a deadning and dulling quality, such as
+  I have observ'd in the <i>Scoria</i> of Lead, Tin, Silver, Copper,
+  <i>&amp;c.</i></p>
+
+  <p>Next, we may also as plainly see the reason of its shining quality,
+  and that is from the even breaking off of the
+  stick, the solid <i>interstitia</i> having a regular termination or
+  surface, and having a pretty strong reflecting quality, the many small
+  reflections become united to the naked eye, and make a very pretty
+  shining surface.</p>
+
+  <p>Thirdly, the reason of its hardness and brittleness seems evident, for
+  since all the watery or liquid substance that moistn'd and toughn'd those
+  <i>Interstitia</i> of the more solid parts, are evaporated and remov'd,
+  that which is left behind becomes of the nature almost of a stone, which
+  will not at all, or very little, bend without a <i>divulsion</i> or
+  <i>solution</i> of its <i>continuity</i>.</p>
+
+  <p>It is not my design at present, to examine the use and
+  <i>Mechanisme</i> of these parts of Wood, that being more proper to
+  another Enquiry; but rather to hint, that from this Experiment we may
+  learn,</p>
+
+  <p>First, what is the cause of the blackness of many burnt bodies, which
+  we may find to be nothing else but this; that the heat of the fire
+  agitating and rarifying the waterish, transparent, and volatile water
+  that is contain'd in them, by the continuation of that action, does so
+  totally expel and drive away all that which before fill'd the pores, and
+  was dispers'd also through the solid mass of it, and thereby caus'd an
+  universal kind of transparency, that it not onely leaves all the pores
+  empty, but all the <i>Interstitia</i> also so dry and <i>opacous</i>, and
+  perhaps also yet further perforated, that that light onely is reflected
+  back which falls upon the very outward edges of the pores, all they that
+  enter into the pores of the body, never returning, but being lost in
+  it.</p>
+
+  <p>Now, that the Charring or coaling of a body is nothing else, may be
+  easily believ'd by one that shall consider the means of its production,
+  which may be done after this, or any such manner. The body to be charr'd
+  or coal'd, may be put into a <i>Crucible</i>, Pot, or any other Vessel
+  that will endure to be made red-hot in the fire without breaking, and
+  then cover'd over with Sand, so as no part of it be suffer'd to be open
+  to the Air, then set into a good fire, and there kept till the Sand has
+  continu'd red hot for a quarter, half, an hour or two, or more, according
+  to the nature and bigness of the body to be coal'd or charr'd, then
+  taking it out of the fire, and letting it stand till it be quite cold,
+  the body may be taken out of the Sand well charr'd and cleans'd of its
+  waterish parts; but in the taking of it out, care must be had that the
+  Sand be very neer cold, for else, when it comes into the free air, it
+  will take fire, and readily burn away.</p>
+
+  <p>This maybe done also in any close Vessel of Glass, as a <i>Retort</i>,
+  or the like, and the several fluid substances that come over may be
+  receiv'd in a fit <i>Recipient</i>, which will yet further countenance
+  this <i>Hypothesis</i>: And their manner of charring Wood in great
+  quantity comes much to the same thing, namely, an application of a great
+  heat to the body, and preserving it from the free access of the devouring
+  air; this may be easily learn'd from the History of Charring of Coal,
+  most excellently describ'd and publish'd by that most accomplish'd
+  Gentleman, Mr. <i>John Evelin</i>, in the 100, 101, 103, pages of his
+  <i>Sylva</i>, to which I shall therefore refer the curious Reader that
+  desires a full information of it.</p>
+
+  <p>Next, we may learn what part of the Wood it is that is the
+  <i>combustible</i> matter, for since we shall find that none, or very
+  little of those fluid substances that are driven over into the Receiver
+  are <i>combustible</i>, and that most of that which is left behind is so,
+  it follows, that the solid <i>interstitia</i> of the Wood are the
+  <i>combustible</i> matter. Further, the reason why uncharr'd Wood burns
+  with a greater flame then that which is charr'd, is as evident, because
+  those waterish or volatil parts issuing out of the fired Wood, every way,
+  not onely shatter and open the body, the better for the fire to enter,
+  but issuing out in vapours or wind, they become like so many little
+  <i>æolipiles</i>, or Bellows, whereby they blow and agitate the fir'd
+  part, and conduce to the more speedy and violent consumption or
+  dissolution of the body.</p>
+
+  <p>Thirdly, from the Experiment of charring of Coals (whereby we see that
+  notwithstanding the great heat, and the duration of it, the solid parts
+  of the Wood remain, whilest they are preserv'd from the free access of
+  the air undissipated) we may learn, that which has not, that I know of,
+  been publish'd or hinted, nay, not so much as thought of, by any; and
+  that in short is this.</p>
+
+  <p>First, <i>that the Air</i> in which we live, move, and breath, and
+  which encompasses very many, and cherishes most bodies it encompasses,
+  that this Air is the <i>menstruum</i>, or universal dissolvent of all
+  <i>Sulphureous</i> bodies.</p>
+
+  <p>Secondly, <i>that this action</i> it performs not, till the body be
+  first sufficiently heated, as we find requisite also to the dissolution
+  of many other bodies by several other <i>menstruums</i>.</p>
+
+  <p>Thirdly, <i>that this action</i> of dissolution, produces or generates
+  a very great heat, and that which we call Fire; and this is common also
+  to many dissolutions of other bodies, made by <i>menstruums</i>, of which
+  I could give multitudes of Instances.</p>
+
+  <p>Fourthly, <i>that this action</i> is perform'd with so great a
+  violence, and does so minutely act, and rapidly agitate the smallest
+  parts of the <i>combustible</i> matter, that it produces in the
+  <i>diaphanous medium</i> of the Air, the action or pulse of light, which
+  what it is, I have else-where already shewn.</p>
+
+  <p>Fifthly, <i>that the dissolution</i> of sulphureous bodies is made by
+  a substance inherent, and mixt with the Air, that is like, if not the
+  very same, with that which is fixt in <i>Salt-peter</i>, which by
+  multitudes of Experiments that may be made with <i>Saltpeter</i>, will, I
+  think, most evidently be demonstrated.</p>
+
+  <p>Sixthly, <i>that in this dissolution</i> of bodies by the Air, a
+  certain part is united and mixt, or dissolv'd and turn'd into the Air,
+  and made to fly up and down with it in the same manner as a
+  <i>metalline</i> or other body dissolved into any <i>menstruums</i>, does
+  follow the motions and progresses of that <i>menstruum</i> till it be
+  precipitated.</p>
+
+  <p>Seventhly, That as there is one part that is dissoluble by the Air, so
+  are there other parts with which the parts of the Air mixing and uniting,
+  do make a <i>Coagulum</i>, or <i>precipitation</i>, as one may call it,
+  which causes it to be separated from the Air, but this <i>precipitate</i>
+  is so light, and in so small and rarify'd or porous clusters, that it is
+  very volatil, and is easily carry'd up by the motion of the Air, though
+  afterwards, when the heat and agitation that kept it
+  rarify'd ceases, it easily condenses, and commixt with other indissoluble
+  parts, it sticks and adheres to the next bodies it meets withall; and
+  this is a certain <i>Salt</i> that may be extracted out of
+  <i>Soot</i>.</p>
+
+  <p>Eighthly, that many indissoluble parts being very apt and prompt to be
+  rarify'd, and so, whilest they continue in that heat and agitation, are
+  lighter then the Ambient Air, are thereby thrust and carry'd upwards with
+  great violence, and by that means carry along with them, not onely that
+  <i>Saline concrete</i> I mention'd before, but many terrestrial, or
+  indissoluble and irrarefiable parts, nay, many parts also which are
+  dissoluble, but are not suffer'd to stay long enough in a sufficient heat
+  to make them prompt and apt for that action. And therefore we find in
+  <i>Soot</i>, not onely a part, that being continued longer in a competent
+  heat, will be dissolv'd by the Air, or take fire and burn; but a part
+  also which is fixt, terrestrial, and irrarefiable.</p>
+
+  <p>Ninthly, that as there are these several parts that will rarifie and
+  fly, or be driven up by the heat, so are there many others, that as they
+  are indissoluble by the <i>aerial menstruum</i>, so are they of such
+  sluggish and gross parts, that they are not easily rarify'd by heat, and
+  therefore cannot be rais'd by it; the volatility or fixtness of a body
+  seeming to consist only in this, that the one is of a texture, or has
+  component parts that will be easily rarify'd into the form of Air, and
+  the other, that it has such as will not, without much ado, be brought to
+  such a constitution; and this is that part which remains behind in a
+  white body call'd Ashes, which contains a substance, or <i>Salt</i>,
+  which Chymists call <i>Alkali</i>: what the particular natures of each of
+  these bodies are, I shall not here examine, intending it in another
+  place, but shall rather add that this <i>Hypothesis</i> does so exactly
+  agree with all <i>Phænomena</i>, of Fire, and so genuinely explicate each
+  particular circumstance that I have hitherto observ'd, that it is more
+  then probable, that this cause which I have assign'd is the true
+  adequate, real, and onely cause of those <i>Phænomena</i>; And therefore
+  I shall proceed a little further, to shew the nature and use of the
+  Air.</p>
+
+  <p>Tenthly, therefore the dissolving parts of the Air are but few, that
+  is, it seems of the nature of those <i>Saline menstruums</i>, or spirits,
+  that have very much flegme mixt with the spirits, and therefore a small
+  parcel of it is quickly glutted, and will dissolve no more; and therefore
+  unless some fresh part of this <i>menstruum</i> be apply'd to the body to
+  be dissolv'd, the action ceases, and the body leaves to be dissolv'd and
+  to shine, which is the Indication of it, though plac'd or kept in the
+  greatest heat; whereas <i>Salt-peter</i> is a <i>menstruum</i>, when
+  melted and red-hot, that abounds more with those Dissolvent particles,
+  and therefore as a small quantity of it will dissolve a great sulphureous
+  body, so will the dissolution be very quick and violent.</p>
+
+  <p>Therefore in the <i>Eleventh</i> place, it is observable, that, as in
+  other solutions, if a copious and quick supply of fresh <i>menstruum</i>,
+  though but weak, be poured on, or applied to the dissoluble body, it
+  quickly consumes it: So this <i>menstruum</i> of the Air, if by Bellows,
+  or any other such contrivance, it be copiously apply'd to the shining
+  body, is found to dissolve it as soon, and as
+  violently as the more strong <i>menstruum</i> of melted <i>Nitre</i>.</p>
+
+  <p>Therefore twelfthly, it seems reasonable to think that there is no
+  such thing as an Element of Fire that should attract or draw up the
+  flame, or towards which the flame should endeavour to ascend out of a
+  desire or appetite of uniting with that as its <i>Homogeneal</i>
+  primitive and generating Element; but that that shining transient body
+  which we call <i>Flame</i>, is nothing else but a mixture of Air, and
+  volatil sulphureous parts of dissoluble or combustible bodies, which are
+  acting upon each other whilst they ascend, that is, flame seems to be a
+  mixture of Air, and the combustible volatil parts of any body, which
+  parts the encompassing Air does dissolve or work upon, which action, as
+  it does intend the heat of the <i>aerial</i> parts of the dissolvent, so
+  does it thereby further rarifie those parts that are acting, or that are
+  very neer them, whereby they growing much lighter then the heavie parts
+  of that <i>menstruum</i> that are more remote, are thereby protruded and
+  driven upward; and this may be easily observ'd also in dissolution made
+  by any other <i>menstruum</i>, especially such as either create heat or
+  bubbles. Now, this action of the <i>menstruum</i>, or <i>Air</i>, on the
+  dissoluble parts, is made with such violence, or is such, that it imparts
+  such a motion or pulse to the <i>diaphanous</i> parts of the Air, as I
+  have elsewhere shewn is requisite to produce light.</p>
+
+  <p>This <i>Hypothesis</i> I have endeavoured to raise from an Infinite of
+  Observations and Experiments, the process of which would be much too long
+  to be here inserted, and will perhaps another time afford matter copious
+  enough for a much larger Discourse, the Air being a Subject which (though
+  all the world has hitherto liv'd and breath'd in, and been unconversant
+  about) has yet been so little truly examin'd or explain'd, that a
+  diligent enquirer will be able to find but very little information from
+  what has been (till of late) written of it: But being once well
+  understood, it will, I doubt not, inable a man to render an intelligible,
+  nay probable, if not the true reason of all the <i>Phænomena</i> of Fire,
+  which, as it has been found by Writers and Philosophers of all Ages a
+  matter of no small difficulty, as may be sufficiently understood by their
+  strange <i>Hypotheses</i>, and unintelligible Solutions of some few
+  <i>Phænomena</i> of it; so will it prove a matter of no small concern and
+  use in humane affairs, as I shall elsewhere endeavour to manifest when I
+  come to shew the use of the Air in respiration, and for the preservation
+  of the life, nay, for the conservation and restauration of the health and
+  natural constitution of mankind as well as all other aereal
+  <i>animals</i>, as also the uses of this principle or propriety of the
+  Air in chymical, mechanical, and other operations. In this place I have
+  onely time to hint an <i>Hypothesis</i>, which, if God permit me life and
+  opportunity, I may elsewhere prosecute, improve and publish. In the mean
+  time, before I finish this Discourse, I must not forget to acquaint the
+  Reader, that having had the liberty granted me of making some trials on a
+  piece of <i>Lignum fossile</i> shewn to the Royal Society, by the
+  eminently Ingenious and Learned Physician, Doctor <i>Ent</i>, who
+  receiv'd it for a Present from the famous <i>Ingenioso Cavalliero de
+  Pozzi</i>, it being one of the fairest and best
+  pieces of <i>Lignum fossile</i> he had seen; Having (I say) taken a small
+  piece of this Wood, and examin'd it, I found it to burn in the open Air
+  almost like other Wood, and insteed of a resinous smoak or fume, it
+  yielded a very bituminous one, smelling much of that kind of sent: But
+  that which I chiefly took notice of, was, that cutting off a small piece
+  of it, about the bigness of my Thumb, and charring it in a
+  <i>Crucible</i> with Sand, after the manner I above prescrib'd, I found
+  it infinitely to abound with the smaller sort of pores, so extreamly
+  thick, and so regularly perforating the substance of it long-ways, that
+  breaking it off a-cross, I found it to look very like an Honey-comb; but
+  as for any of the second, or bigger kind of pores, I could not find that
+  it had any; so that it seems, whatever were the cause of its production,
+  it was not without those small kind of pores which we have onely hitherto
+  found in Vegetable bodies: and comparing them with the pores which I have
+  found in the Charcoals that I by this means made of several other kinds
+  of Wood, I find it resemble none so much as those of Fire, to which it is
+  not much unlike in grain also, and several other proprieties.</p>
+
+  <p>And therefore, what ever is by some, who have written of it, and
+  particularly by <i>Francisco Stelluto</i>, wrote a Treatise in
+  <i>Italian</i> of that Subject, which was Printed at <i>Rome</i>, 1637,
+  affirm'd that it is a certain kind of Clay or Earth, which in tract of
+  time is turn'd into Wood; I rather suspect the quite contrary, that it
+  was at first certain great Trees of Fir or Pine, which by some
+  Earthquake, or other casualty, came to be buried under the Earth, and was
+  there, after a long time's residence (according to the several natures of
+  the encompassing adjacent parts) either rotted and turn'd into a kind of
+  Clay, or <i>petrify'd</i> and turn'd into a kind of Stone, or else had
+  its pores fill'd with certain Mineral juices, which being stay'd in them,
+  and in tract of time coagulated, appear'd, upon cleaving out, like small
+  Metaline Wires, or else from some flames or scorching forms that are the
+  occasion oftentimes, and usually accompany Earthquakes, might be blasted
+  and turn'd into Coal, or else from certain <i>subterraneous</i> fires
+  which are affirm'd by that Authour to abound much about those parts
+  (namely, in a Province of <i>Italy</i>, call'd <i>Umbria</i>, now the
+  <i>Dutchie</i> of <i>Spoletto</i>, in the Territory of <i>Todi</i>,
+  anciently call'd <i>Tudor</i>; and between the two Villages of
+  <i>Collesecco</i> and <i>Rosaro</i> not far distant from the high-way
+  leading to <i>Rome</i>, where it is found in greater quantity then
+  elsewhere) are by reason of their being encompassed with Earth, and so
+  kept close from the dissolving Air, charr'd and converted into Coal. It
+  would be too long a work to describe the several kinds of pores which I
+  met withall, and by this means discovered in several other Vegetable
+  bodies; nor is it my present design to expatiate upon Instances of the
+  same kind, but rather to give a Specimen of as many kinds as I have had
+  opportunity as yet of observing, reserving the prosecution and enlarging
+  on particulars till a more fit opportunity; and in prosecution of this
+  design, I shall here add:</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXVII" id="obsXVII">XVII</a>. <i>Of </i>Petrify'd wood<i>, and other </i>Petrify'd bodies<i>.</i></h3>
+
+  <p>Of this sort of substance, I observ'd several pieces of very differing
+  kinds, both for their outward shape, colour, grain, <i>texture</i>,
+  hardness, <i>&amp;c.</i> some being brown and redish; others gray, like a
+  Hone; others black, and Flint-like: some soft, like a Slate or Whetstone,
+  others as hard as a Flint, and as brittle. That which I more particular
+  examin'd, was a piece about the bigness of a mans hand, which seem'd to
+  have been a part of some large tree, that by rottenness had been broken
+  off from it before it began to be <i>petrify'd</i>.</p>
+
+  <p>And indeed, all that I have yet seen, seem to have been rotten Wood
+  before the petrifaction was begun; and not long since, examining and
+  viewing a huge great <i>Oak</i>, that seem'd with meer age to be rotten
+  as it stood, I was very much confirm'd in this opinion; for I found, that
+  the grain, colour, and shape of the Wood, was exactly like this
+  <i>petrify'd</i> substance; and with a <i>Microscope</i>, I found, that
+  all those <i>Microscopical</i> pores, which in sappy or firm and sound
+  Wood are fill'd with the natural or innate juices of those Vegetables, in
+  this they were all empty, like those of <i>Vegetables charr'd</i>; but
+  with this difference, that they seem'd much larger then I have seen any
+  in <i>Char-coals</i>; nay, even then those of Coals made of great blocks
+  of Timber, which are commonly call'd <i>Old-coals</i>.</p>
+
+  <p>The reason of which difference may probably be, that the charring of
+  Vegetables, being an operation quickly perform'd, and whilest the Wood is
+  sappy, the more solid parts may more easily shrink together, and contract
+  the pores or <i>interstitia</i> between them, then in the rotten Wood,
+  where that natural juice seems onely to be wash'd away by
+  <i>adventitious</i> or unnatural moisture; and so though the natural
+  juice be wasted from between the firm parts, yet those parts are kept
+  asunder by the <i>adventitious</i> moystures, and so by degrees settled
+  in those postures.</p>
+
+  <p>And this I likewise found in the <i>petrify'd</i> Wood, that the pores
+  were somewat bigger then those of <i>Charcoal</i>, each pore being neer
+  upon half as bigg again, but they did not bear that disproportion which
+<span class="sidenote">
+<a href="images/scheme-10.png" target="_blank"><i>Schem.</i> 10.</a><br /><i>Fig.</i> 1, 2.
+</span>
+  is exprest in the tenth <i>Scheme</i>, between the small specks or pores
+  in the first Figure (which representeth the pores of Coal or Wood
+  charr'd) and the black spots of the second Figure (which represent the
+  like <i>Microscopical pores</i> in the <i>petrify'd</i> Wood) for these
+  last were drawn by a <i>Microscope</i> that magnify'd the object above
+  six times more in Diameter then the <i>Microscope</i> by which those
+  pores of Coal were observ'd.</p>
+
+  <p>Now, though they were a little bigger, yet did they keep the exact
+  figure and order of the pores of Coals and of rotten Wood, which last
+  also were much of the same cize.</p>
+
+  <p>The other Observations on this <i>petrify'd</i> substance, that a
+  while since, by the appointment of the <i>Royal Society</i>, I made, and
+  presented to them an account of, were these that follow, which had the
+  honour done them by the most accomplish'd Mr. <i>Evelin</i>,
+  my highly honoured friend, to be inserted and published among those
+  excellent Observations wherewith his <i>Sylva</i> is replenish'd, and
+  would therefore have been here omitted, had not the Figure of them, as
+  they appear'd through the <i>Microscope</i> been before that
+  engraven.</p>
+
+  <p>This <i>Petrify'd</i> substance resembled Wood, in that</p>
+
+  <p>First, all the parts of it seem'd not at all <i>dislocated</i>, or
+  alter'd from their natural Position, whil'st they were Wood, but the
+  whole piece retain'd the exact shape of Wood, having many of the
+  conspicuous pores of wood still remaining pores, and shewing a manifest
+  difference visible enough between the grain of the Wood and that of the
+  bark, especially when any side of it was cut smooth and polite; for then
+  it appear'd to have a very lovely grain, like that of some curious close
+  Wood.</p>
+
+  <p>Next (it resembled Wood) in that all the smaller and (if I may so call
+  those which are onely visible with a good magnifying Glass)
+  <i>Microscopical</i> pores of it appear (both when the substance is cut
+  and polish'd <i>transversly</i> and <i>parallel</i> to the pores of it)
+  perfectly like the <i>Microscopical</i> pores of several kinds of Wood,
+  especially like and equal to those of several sorts of rotten Wood which
+  I have since observ'd, retaining both the shape, position and magnitude
+  of such pores. It was differing from Wood:</p>
+
+  <p>First; in <i>weight</i>, being to common water as 3Πto 1. whereas
+  there are few of our <i>English</i> Woods, that when very dry are found
+  to be full as heavie as water.</p>
+
+  <p>Secondly, in <i>hardness</i>, being very neer as hard as a Flint; and
+  in some places of it also resembling the grain of a Flint: and, like it,
+  it would very readily cut Glass, and would not without difficulty,
+  especially in some parts of it, be scratch'd by a black hard Flint: It
+  would also as readily strike fire against a Steel, or against a Flint, as
+  any common Flint.</p>
+
+  <p>Thirdly, in the <i>closeness</i> of it, for though all the
+  <i>Microscopical</i> pores of this <i>petrify'd</i> substance were very
+  conspicuous in one position, yet by altering that position of the
+  polish'd surface to the light, it was also manifest, that those pores
+  appear'd darker then the rest of the body, onely because they were fill'd
+  up with a more duskie substance, and not because they were hollow.</p>
+
+  <p>Fourthly, in its <i>incombustibleness</i>, in that it would not burn
+  in the fire; nay, though I kept it a good while red-hot in the flame of a
+  Lamp, made very <i>intense</i> by the blast of a small Pipe, and a large
+  Charcoal, yet it seem'd not at all to have diminish'd its extension; but
+  only I found it to have chang'd its colour, and to appear of a more dark
+  and duskie brown colour; nor could I perceive that those parts which
+  seem'd to have been Wood at first, were any thing wasted, but the parts
+  appear'd as solid and close as before. It was further observable also,
+  that as it did not consume like Wood, so neither did it crack and flie
+  like a Flint, or such like hard Stone, nor was it long before it appear'd
+  red-hot.</p>
+
+  <p>Fifthly, in its <i>dissolubleness</i>; for putting some drops of
+  distill'd <i>Vinegar</i> upon the Stone, I found it presently to yield
+  very many Bubbles, just like those which may be observ'd in spirit of
+  <i>Vinegar</i> when it corrodes <i>corals</i>, though
+  perhaps many of those small Bubbles might proceed from some small parcels
+  of Air which were driven out of the pores of this <i>petrify'd</i>
+  substance by the insinuating liquid <i>menstruum</i>.</p>
+
+  <p>Sixthly, in its <i>rigidness</i>, and <i>friability</i>, being not at
+  all flexible but brittle like a Flint, insomuch that I could with one
+  knock of a Hammer break off a piece of it, and with a few more, reduce
+  that into a pretty fine powder.</p>
+
+  <p>Seventhly, it seem'd also very differing from Wood to the
+  <i>touch</i>, <i>feeling</i> more cold then Wood usually does, and much
+  like other close stones and Minerals.</p>
+
+  <p>The Reasons of all which <i>Phænomena</i> seem to be,</p>
+
+  <p>That <i>petrify'd</i> Wood having lain in some place where it was well
+  soak'd with <i>petrifying</i> water (that is, such a water as is well
+  <i>impregnated</i> with stony and earthy particles) did by degrees
+  separate, either by straining and <i>filtration</i>, or perhaps, by
+  <i>precipitation</i>, <i>cohesion</i> or <i>coagulation</i>, abundance of
+  stony particles from the permeating water, which stony particles, being
+  by means of the fluid <i>vehicle</i> convey'd, not onely into the
+  <i>Microscopical</i> pores, and so perfectly stoping them up, but also
+  into the pores or <i>interstitia</i>, which may, perhaps, be even in the
+  texture or <i>Schematisme</i> of that part of the Wood, which, through
+  the <i>Microscope</i>, appears most solid, do thereby so augment the
+  weight of the Wood, as to make it above three times heavier then water,
+  and perhaps, six times as heavie as it was when Wood.</p>
+
+  <p>Next, they thereby so lock up and fetter the parts of the Wood, that
+  the fire cannot easily make them flie away, but the action of the fire
+  upon them is onely able to <i>Char</i> those parts, as it were, like a
+  piece of Wood, if it be clos'd very fast up in Clay, and kept a good
+  while red-hot in the fire, will by the heat of the fire be charr'd and
+  not consum'd, which may, perhaps, also be somewhat of the cause, why the
+  <i>petrify'd</i> substance appear'd of a dark brown colour after it had
+  been burnt.</p>
+
+  <p>By this <i>intrusion</i> of the <i>petrifying</i> particles, this
+  substance also becomes hard and <i>friable</i>; for the smaller pores of
+  the Wood being perfectly wedg'd, and stuft up with those stony particles,
+  the small parts of the Wood have no places or pores into which they may
+  slide upon bending, and consequently little or no flexion or yielding at
+  all can be caus'd in such a substance.</p>
+
+  <p>The remaining particles likewise of the Wood among the stony
+  particles, may keep them from cracking and flying when put into the fire,
+  as they are very apt to do in a Flint.</p>
+
+  <p>Nor is Wood the onely substance that may by this kind of
+  <i>transmutation</i> be chang'd into stone; for I my self have seen and
+  examin'd very many kinds of substances, and among very credible Authours,
+  we may meet with Histories of such <i>Metamorphoses</i> wrought almost on
+  all kind of substances, both <i>Vegetable</i> and <i>Animal</i>, which
+  Histories, it is not my business at present, either to relate, or
+  <i>epitomise</i>, but only to set down some Observation I lately made on
+  several kind of <i>petrify'd</i> Shels, found about <i>Keinsham</i>,
+  which lies within four or five miles of <i>Bristol</i>, which are
+  commonly call'd <i>Serpentine-stones.</i></p>
+
+  <p>Examining several of these very curiously figur'd bodies (which are
+  commonly thought to be Stones form'd by some extraordinary <i>Plastick
+  virtue</i> <i>latent</i> in the Earth itself) I took notice of these
+  particulars:</p>
+
+  <p>First, that these figured bodies, or stones, were of very differing
+  substances, as to hardness: some of Clay, some Marle, some soft Stone,
+  almost of the hardness of those soft stones which Masons call Fire-stone,
+  others as hard as Portland stone, others as hard as Marble, and some as
+  hard as a Flint or Crystal.</p>
+
+  <p>Next, they were of very differing substances as to transparency and
+  colour; some white, some almost black, some brown, some Metalline, or
+  like Marchasites; some transparent like white Marble, others like flaw'd
+  Crystal, some gray, some of divers colours; some radiated like those long
+  <i>petrify'd drops</i>, which are commonly found at the <i>Peak</i>, and
+  in other <i>subterraneous caverns</i>, which have a kind of pith in the
+  middle.</p>
+
+  <p>Thirdly, that they were very different as to the manner of their
+  outward figuration; for some of them seem'd to have been the substance
+  that had fill'd the Shell of some kind of Shel-fish; others, to have been
+  the substance that had contain'd or enwrapp'd one of those Shels, on both
+  which, the perfect impression either of the inside or outside of such
+  Shells seem'd to be left, but for the most part, those impressions seem'd
+  to be made by an imperfect or broken Shell, the great end or mouth of the
+  Shell being always wanting, and often times the little end, and sometimes
+  half, and in some there were impressions, just as if there had been holes
+  broken in the figurating, imprinting or moulding Shell; some of them
+  seem'd to be made by such a Shell very much brused or flaw'd, insomuch
+  that one would verily have thought that very figur'd stone had been
+  broken or brused whilst a gelly, as 'twere, and so hardned, but within in
+  the grain of the stone, there appear'd not the least sign of any such
+  bruse or breaking, but onely on the very uttermost superficies.</p>
+
+  <p>Fourthly, they were very different, as to their outward covering, some
+  having the perfect Shell, both in figure, colour, and substance, sticking
+  on upon its surface, and adhering to it, but might very easily be
+  separated from it, and like other common <i>Cockle</i> or
+  <i>Scolop-shels</i>, which some of them most accurately resembled, were
+  very dissoluble in common <i>Vinegar</i>, others of them, especially
+  those <i>Serpentine</i>, or <i>Helical stones</i> were cover'd or
+  retained the shining or Pearl-colour'd substance of the inside of a Shel,
+  which substance, on some parts of them, was exceeding thin, and might
+  very easily be rubbed off; on other parts it was pretty thick, and
+  retained a white coat, or flaky substance on the top, just like the
+  outsides of such Shells; some of them had very large pieces of the Shell
+  very plainly sticking on to them, which were easily to be broken or
+  flaked off by degrees: they likewise, some of them retain'd all along the
+  surface of them very pretty kind of <i>sutures</i>, such as are observ'd
+  in the skulls of several kinds of living creatures, which <i>sutures</i>
+  were most curiously shap'd in the manner of leaves, and every one of them
+  in the same Shell, exactly one like another, which I was able to discover
+  plainly enough with my naked eye, but more perfectly and distinctly with
+  my <i>Microscope</i>; all these sutures, by breaking
+  some of these stones, I found to be the <i>termini</i>, or boundings of
+  certain <i>diaphragms</i>, or partitions, which seem'd to divide the
+  cavity of the Shell into a multitude of very proportionate and regular
+  <i>cells</i> or <i>caverns</i>, these <i>Diaphragms</i>, in many of them,
+  I found very perfect and compleat, of a very distinct substance from that
+  which fill'd the cavities, and exactly of the same kind with that which
+  covered the outside, being for the most part whitish, or
+  <i>mother-of-pearl</i> colour'd.</p>
+
+  <p>As for the cavities between those <i>Diaphragms</i>, I found some of
+  them fill'd with Marle, and others with several kinds of stones, others,
+  for the most part hollow, onely the whole cavity was usually covered over
+  with a kind of <i>tartareous petrify'd</i> substance, which stuck about
+  the sides, and was there shot into very curious regular Figures, just as
+  <i>Tartar</i>, or other dissolv'd Salts are observ'd to stick and
+  <i>crystallize</i> about the sides of the containing Vessels; or like
+  those little <i>Diamants</i> which I before observed to have covered the
+  vaulted cavity of a Flint; others had these cavities all lin'd with a
+  kind of <i>metalline</i> or <i>marchasite-like</i> substance, which with
+  a <i>Microscope</i> I could as plainly see most curiously and regularly
+  figured, as I had done those in a Flint.</p>
+
+  <p>From all which, and several other particulars which I observ'd, I
+  cannot but think, that all these, and most other kinds of stony bodies
+  which are found thus strangely figured, do owe their formation and
+  figuration, not to any kind of <i>Plastick virtue</i> inherent in the
+  earth, but to the Shells of certain Shel-fishes, which, either by some
+  Deluge, Inundation, Earthquake, or some such other means, came to be
+  thrown to that place, and there to be fill'd with some kind of Mudd or
+  Clay, or <i>petrifying</i> Water, or some other substance, which in tract
+  of time has been settled together and hardned in those shelly moulds into
+  those shaped substances we now find them; that the great and thin end of
+  these Shells by that Earthquake, or what ever other extraordinary cause
+  it was that brought them thither, was broken off; and that many others
+  were otherwise broken, bruised and disfigured; that these Shells which
+  are thus <i>spirallied</i> and separated with <i>Diaphragmes</i>, were
+  some kind of <i>Nautili</i> or <i>Porcelane shells</i>; and that others
+  were shells of <i>Cockles</i>, <i>Muscles</i>, <i>Periwincles</i>,
+  <i>Scolops</i>, &amp;c. of various sorts; that these Shells in many, from
+  the particular nature of the containing or enclos'd Earth, or some other
+  cause, have in tract of time rotted and mouldred away, and onely left
+  their impressions, both on the containing and contained substances; and
+  so left them pretty loose one within another, so that they may be easily
+  separated by a knock or two of a Hammer. That others of these Shells,
+  according to the nature of the substances adjacent to them, have, by a
+  long continuance in that posture, been <i>petrify'd</i> and turn'd into
+  the nature of stone, just as I even now observ'd several sorts of Wood to
+  be. That oftentimes the Shell may be found with one kind of substance
+  within, and quite another without; having, perhaps, been fill'd in one
+  place, and afterwards translated to another, which I have very frequently
+  observ'd in <i>Cockle</i>, <i>Muscle</i>, <i>Periwincle</i>, and other
+  shells, which I have found by the Sea side. Nay, further, that some parts
+  of the same Shell may be fill'd in one place, and some
+  other caverns in another, and others in a third, or a fourth, or a fifth
+  place, for so many differing substances have I found in one of these
+  <i>petrify'd</i> Shells, and perhaps all these differing from the
+  encompassing earth or stone; the means how all which varieties may be
+  caus'd, I think, will not be difficult to conceive, to any one that has
+  taken notice of those Shells, which are commonly found on the Sea shore:
+  And he that shall throughly examine several kinds of such curiously
+  form'd stones, will (I am very apt to think) find reason to suppose their
+  generation or formation to be ascribable to some such accidents as I have
+  mention'd, and not to any <i>Plastick virtue</i>: For it seems to me
+  quite contrary to the infinite prudence of Nature, which is observable in
+  all its works and productions, to design every thing to a determinate
+  end, and for the attaining of that end, makes use of such ways as are (as
+  farr as the knowledge of man has yet been able to reach) altogether
+  consonant, and most agreeable to man's reason, and of no way or means
+  that does contradict, or is contrary to humane Ratiocination; whence it
+  has a long time been a general observation and <i>maxime</i>, that
+  <i>Nature does nothing in vain</i>; It seems, I say, contrary to that
+  great Wisdom of Nature, that these prettily shap'd bodies should have all
+  those curious Figures and contrivances (which many of them are adorn'd
+  and contriv'd with) generated or wrought by a <i>Plastick virtue</i>, for
+  no higher end, then onely to exhibite such a form; which he that shall
+  throughly consider all the circumstances of such kind of Figur'd bodies,
+  will, I think, have great reason to believe, though, I confess, one
+  cannot presently be able to find out what Nature's designs are. It were
+  therefore very desirable, that a good collection of such kind of figur'd
+  stones were collected; and as many particulars, circumstances, and
+  informations collected with them as could be obtained, that from such a
+  History of Observations well rang'd, examin'd and digested, the true
+  original or production of all those kinds of stones might be perfectly
+  and surely known; such as are <i>Thunder-stones</i>, <i>Lapides
+  Stellares</i>, <i>Lapides Judaici</i>, and multitudes of other, whereof
+  mention is made in <i>Aldonandus</i>, <i>Wormius</i>, and other Writers
+  of Minerals.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXVIII" id="obsXVIII">XVIII</a>. <i>Of the </i>Schematisme<i> or </i>Texture<i> of </i>Cork<i>, and
+of the Cells and Pores of some other such frothy Bodies.</i></h3>
+
+  <p>I took a good clear piece of Cork, and with a Pen-knife sharpen'd as
+  keen as a Razor, I cut a piece of it off, and thereby left the surface of
+  it exceeding smooth, then examining it very diligently with a
+  <i>Microscope</i>, me thought I could perceive it to appear a little
+  porous; but I could not so plainly distinguish them, as to be sure that
+  they were pores, much less what Figure they were of: But judging from the
+  lightness and yielding quality of the Cork, that certainly the texture
+  could not be so curious, but that possibly, if I could use
+  some further diligence, I might find it to be discernable with a
+  <i>Microscope</i>, I with the same sharp Penknife, cut off from the
+  former smooth surface an exceeding thin piece of it, and placing it on a
+  black object Plate, because it was it self a white body, and casting the
+  light on it with a deep <i>plano-convex Glass</i>, I could exceeding
+  plainly perceive it to be all perforated and porous, much like a
+  Honey-comb, but that the pores of it were not regular; yet it was not
+  unlike a Honey-comb in these particulars.</p>
+
+  <p>First, in that it had a very little solid substance, in comparison of
+  the empty cavity that was contain'd between, as does more manifestly
+<span class="sidenote">
+<a href="images/scheme-11.png" target="_blank"><i>Schem.</i> 11.</a><br /><i>Fig.</i> 1.
+</span>
+  appear by the Figure A and B of the XI. <i>Scheme</i>, for the
+  <i>Interstitia</i>, or walls (as I may so call them) or partitions of
+  those pores were neer as thin in proportion to their pores, as those thin
+  films of Wax in a Honey-comb (which enclose and constitute the
+  <i>sexangular celts</i>) are to theirs.</p>
+
+  <p>Next, in that these pores, or cells, were not very deep, but consisted
+  of a great many little Boxes, separated out of one continued long pore,
+  by certain <i>Diaphragms</i>, as is visible by the Figure B, which
+  represents a sight of those pores split the long-ways.</p>
+
+  <p>I no sooner discern'd these (which were indeed the first
+  <i>microscopical</i> pores I ever saw, and perhaps, that were ever seen,
+  for I had not met with any Writer or Person, that had made any mention of
+  them before this) but me thought I had with the discovery of them,
+  presently hinted to me the true and intelligible reason of all the
+  <i>Phænomena</i> of Cork; As,</p>
+
+  <p>First, if I enquir'd why it was so exceeding light a body? my
+  <i>Microscope</i> could presently inform me that here was the same reason
+  evident that there is found for the lightness of froth, an empty
+  Honey-comb, Wool, a Spunge, a Pumice-stone, or the like; namely, a very
+  small quantity of a solid body, extended into exceeding large
+  dimensions.</p>
+
+  <p>Next, it seem'd nothing more difficult to give an intelligible reason,
+  why Cork is a body so very unapt to suck and drink in Water, and
+  consequently preserves it self, floating on the top of Water, though left
+  on it never so long: and why it is able to stop and hold air in a Bottle,
+  though it be there very much condens'd and consequently presses very
+  strongly to get a passage out, without suffering the least bubble to pass
+  through its substance. For, as to the first, since our <i>Microscope</i>
+  informs us that the substance of Cork is altogether fill'd with Air, and
+  that that Air is perfectly enclosed in little Boxes or Cells distinct
+  from one another. It seems very plain, why neither the Water, nor any
+  other Air can easily insinuate it self into them, since there is already
+  within them an <i>intus existens</i>, and consequently, why the pieces of
+  Cork become so good floats for Nets, and stopples for Viols, or other
+  close Vessels.</p>
+
+  <p>And thirdly, if we enquire why Cork has such a springiness and
+  swelling nature when compress'd? and how it comes to suffer so great a
+  compression, or seeming penetration of dimensions, so as to be made a
+  substance as heavie again and more, bulk for bulk, as it was before
+  compression, and yet suffer'd to return, is found to extend it self again
+  into the same space? Our <i>Microscope</i> will easily inform us, that
+  the whole mass consists of an infinite company of small
+  Boxes or Bladders of Air, which is a substance of a springy nature, and
+  that will suffer a considerable condensation (as I have several times
+  found by divers trials, by which I have most evidently condens'd it into
+  less then a twentieth part of its usual dimensions neer the Earth, and
+  that with no other strength then that of my hands without any kind of
+  forcing Engine, such as Racks, Leavers, Wheels, Pullies, or the like, but
+  this onely by and by) and besides, it seems very probable that those very
+  films or sides of the pores, have in them a springing quality, as almost
+  all other kind of Vegetable substances have, so as to help to restore
+  themselves to their former position.</p>
+
+  <p>And could we so easily and certainly discover the <i>Schematisme</i>
+  and <i>Texture</i> even of these films, and of several other bodies, as
+  we can these of Cork; there seems no probable reason to the contrary, but
+  that we might as readily render the true reason of all their
+  <i>Phænomena</i>; as namely, what were the cause of the springingess, and
+  toughness of some, both as to their flexibility and restitution. What, of
+  the friability or brittleness of some others, and the like; but till such
+  time as our <i>Microscope</i>, or some other means, enable us to discover
+  the true <i>Schematism</i> and <i>Texture</i> of all kinds of bodies, we
+  must grope, as it were, in the dark, and onely ghess at the true reasons
+  of things by similitudes and comparisons.</p>
+
+  <p>But, to return to our Observation. I told several lines of these
+  pores, and found that there were usually about threescore of these small
+  Cells placed end-ways in the eighteenth part of an Inch in length, whence
+  I concluded there must be neer eleven hundred of them, or somewhat more
+  then a thousand in the length of an Inch, and therefore in a square Inch
+  above a Million, or 1166400. and in a Cubick Inch, above twelve hundred
+  Millions, or 1259712000. a thing almost incredible, did not our
+  <i>Microscope</i> assure us of it by ocular demonstration; nay, did it
+  not discover to us the pores of a body, which were they
+  <i>diaphragm'd</i>, like those of Cork, would afford us in one Cubick
+  Inch, more then ten times as many little Cells, as is evident in several
+  charr'd Vegetables; so prodigiously curious are the works of Nature, that
+  even these conspicuous pores of bodies, which seem to be the channels or
+  pipes through which the <i>Succus nutritius</i>, or natural juices of
+  Vegetables are convey'd, and seem to correspond to the veins, arteries
+  and other Vessels in sensible creatures, that these pores I say, which
+  seem to be the Vessels of nutrition to the vastest body in the World, are
+  yet so exceeding small, that the <i>Atoms</i> which <i>Epicurus</i>
+  fancy'd would go neer to prove too bigg to enter them, much more to
+  constitute a fluid body in them. And how infinitely smaller then must be
+  the Vessels of a Mite, or the pores of one of those little Vegetables I
+  have discovered to grow on the back-side of a Rose-leaf, and shall anon
+  more fully describe, whose bulk is many millions of times less then the
+  bulk of the small shrub it grows on; and even that shrub, many millions
+  of times less in bulk then several trees (that have heretofore grown in
+  <i>England</i>, and are this day flourishing in other hotter Climates, as
+  we are very credibly inform'd) if at least the pores of this small
+  Vegetable should keep any such proportion to the body of it, as we have
+  found these pores of other Vegetables to do to
+  their bulk. But of these pores I have said more elsewhere.</p>
+
+  <p>To proceed then, Cork seems to be by the transverse constitution of
+  the pores, a kind of <i>Fungus</i> or Mushrome, for the pores lie like so
+  many Rays tending from the center, or pith of the tree, outwards; so that
+  if you cut off a piece from a board of Cork transversly, to the flat of
+  it, you will, as it were, split the pores, and they will appear just as
+  they are express'd in the Figure B of the XI. <i>Scheme</i>. But if you
+  shave off a very thin piece from this board, parallel to the plain of it,
+  you will cut all the pores transversly, and they will appear almost as
+  they are express'd in the Figure A, save onely the solid
+  <i>Interstitia</i> will not appear so thick as they are there
+  represented.</p>
+
+  <p>So that Cork seems to suck its nourishment from the subjacent bark of
+  the Tree immediately, and to be a kind of excrescence, or a substance
+  distinct from the substances of the entire Tree, something
+  <i>analogus</i> to the Mushrome, or Moss on other Trees, or to the hairs
+  on Animals. And having enquir'd into the History of Cork, I find it
+  reckoned as an excrescency of the bark of a certain Tree, which is
+  distinct from the two barks that lie within it, which are common also to
+  other trees; That 'tis some time before the Cork that covers the young
+  and tender sprouts comes to be discernable; That it cracks, flaws, and
+  cleaves into many great chaps, the bark underneath remaining entire; That
+  it may be separated and remov'd from the Tree, and yet the two
+  under-barks (such as are also common to that with other Trees) not at all
+  injur'd, but rather helped and freed from an external injury. Thus
+  <i>Jonstonus</i> in <i>Dendrologia</i>, speaking <i>de Subere</i>, says,
+  <i>Arbor est procera, Lignum est robustum, dempto cortice in aquis non
+  fluitat, Cortice in orbem detracto juvatur, crascescens enim præstringit
+  &amp; strangulat, intra triennium iterum repletur: Caudex ubi adolescit
+  crassus, cortex superior densus carnosus, duos digitos crassus, scaber,
+  rimosus, &amp; qui nisi detrahatur dehiscit, alioque subnascente
+  expellitur, interior qui subest novellus ita rubet ut arbor minio picta
+  videatur</i>. Which Histories, if well consider'd, and the tree,
+  substance, and manner of growing, if well examin'd, would, I am very apt
+  to believe, much confirm this my conjecture about the origination of
+  Cork.</p>
+
+  <p>Nor is this kind of Texture peculiar to Cork onely; for upon
+  examination with my <i>Microscope</i>, I have found that the pith of an
+  Elder, or almost any other Tree, the inner pulp or pith of the Cany
+  hollow stalks of several other Vegetables: as of Fennel, Carrets, Daucus,
+  Bur-docks, Teasels, Fearn, some kinds of Reeds, <i>&amp;c.</i> have much
+  such a kind of <i>Schematisme</i>, as I have lately shewn that of Cork,
+  save onely that here the pores are rang'd the long-ways, or the same ways
+  with the length of the Cane, whereas in Cork they are transverse.</p>
+
+  <p>The pith also that fills that part of the stalk of a Feather that is
+  above the Quil, has much such a kind of texture, save onely that which
+  way soever I set this light substance, the pores seem'd to be cut
+  transversly; so that I ghess this pith which fills the Feather, not to
+  consist of abundance of long pores separated with Diaphragms, as Cork
+  does, but to be a kind of solid or hardned froth,
+  or a <i>congeries</i> of very small bubbles consolidated in that form,
+  into a pretty stiff as well as tough concrete, and that each Cavern,
+  Bubble, or Cell, is distinctly separate from any of the rest, without any
+  kind of hole in the encompassing films, so that I could no more blow
+  through a piece of this kinde of substance, then I could through a piece
+  of Cork, or the sound pith of an Elder.</p>
+
+  <p>But though I could not with my <i>Microscope</i>, nor with my breath,
+  nor any other way I have yet try'd, discover a passage out of one of
+  those cavities into another, yet I cannot thence conclude, that therefore
+  there are none such, by which the <i>Succus nutritius</i>, or appropriate
+  juices of Vegetables, may pass through them; for, in several of those
+  Vegetables, whil'st green, I have with my <i>Microscope</i>, plainly
+  enough discover'd these Cells or Poles fill'd with juices, and by degrees
+  sweating them out; as I have also observed in green Wood all those long
+  <i>Microscopical</i> pores which appear in Charcoal perfectly empty of
+  any thing but Air.</p>
+
+  <p>Now, though I have with great diligence endeavoured to find whether
+  there be any such thing in those <i>Microscopical</i> pores of Wood or
+  Piths, as the <i>Valves</i> in the heart, veins, and other passages of
+  Animals, that open and give passage to the contain'd fluid juices one
+  way, and shut themselves, and impede the passage of such liquors back
+  again, yet have I not hitherto been able to say any thing positive in it;
+  though, me thinks, it seems very probable, that Nature has in these
+  passages, as well as in those of Animal bodies, very many appropriated
+  Instruments and contrivances, whereby to bring her designs and end to
+  pass, which 'tis not improbable, but that some diligent Observer, if
+  help'd with better <i>Microscopes</i>, may in time detect.</p>
+
+  <p>And that this may be so, seems with great probability to be argued
+  from the strange <i>Phænomena</i> of sensitive Plants, wherein Nature
+  seems to perform several Animal actions with the same <i>Schematism</i>
+  or <i>Orginization</i> that is common to all Vegetables, as may appear by
+  some no less instructive then curious Observations that were made by
+  divers Eminent Members of the <i>Royal Society</i> on some of these kind
+  of Plants, whereof an account was delivered in to them by the most
+  Ingenious and Excellent <i>Physician</i>, Doctor <i>Clark</i>, which,
+  having that liberty granted me by that most Illustrious Society, I have
+  hereunto adjoyn'd.</p>
+
+<h3><i>Observations on the </i>Humble<i> and </i>Sensible Plants<i> in </i>M Chiffin's<i>
+Garden in Saint </i>James<i>'s Park, made </i>August<i> the </i>9<sup>th,</sup> 1661<i>.</i>
+<i>Present, the</i> Lord <i>Brouncker</i>, Sr. <i>Robert Moray</i>, Dr. <i>Wilkins</i>,
+Mr. <i>Evelin</i>, Dr. <i>Henshaw</i>, <i>and</i> Dr. <i>Clark</i>.</h3>
+
+<blockquote>
+  <p>There are four Plants, two of which are little shrub Plants, with a
+  little short stock, about an Inch above the ground, from whence are
+  spread several sticky branches, round, streight, and   smooth in the distances between the Sprouts, but just under the Sprouts
+  there are two sharp thorny prickles, broad in the letting on, as in the
+  Bramble, one just under the Sprout, the other on the opposite side of the
+  branch.</p>
+
+<span class="sidenote">
+<a href="images/scheme-11.png" target="_blank"><i>Schem.</i> 11.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>The distances betwixt the Sprouts are usually something more then an Inch,
+  and many upon a Branch, according to its length, and they grew so, that
+  if the lower Sprout be on the left side of the Branch, the next above is
+  on the right, and so to the end, not sprouting by pairs.</p>
+
+  <p>At the end of each Sprout are generally four sprigs, two at the
+  Extremity, and one on each side, just under it. At the first sprouting of
+  these from the Branch to the Sprig where the leaves grow, they are full
+  of little short white hairs, which wear off as the leaves grow, and then
+  they are smooth as the Branch.</p>
+
+  <p>Upon each of these sprigs, are, for the most part, eleven pair of
+  leaves, neatly set into the uppermost part of the little sprig, exactly
+  one against another, as it were in little <i>articulations</i>, such as
+  Anatomists call <i>Enarthrosis</i>, where the round head of a Bone is
+  received into another fitted for its motion; and standing very fitly to
+  shut themselves and touch, the pairs just above them closing somewhat
+  upon them, as in the shut sprig; so is the little round <i>Pedunculus</i>
+  of this leaf fitted into a little cavity of the sprig, visible to the eye
+  in a sprig new pluck'd, or in a sprig withered on the Branch, from which
+  the leaves easily fall by touching.</p>
+
+  <p>The leaf being almost an oblong square, and set into the
+  <i>Pedunculus</i>, at one of the lower corners, receiveth from that not
+  onely a <i>Spine</i>, as I may call it, which, passing through the leaf,
+  divides it so length-ways that the outer-side is broader then the inner
+  next the sprig, but little <i>fibres</i> passing obliquely towards the
+  opposite broader side, seem to make it here a little muscular, and fitted
+  to move the whole leaf, which, together with the whole sprig, are set
+  full with little short whitish hairs.</p>
+
+  <p>One of these Plants, whose branch seem'd to be older and more grown
+  then the other, onely the tender Sprouts of it, after the leaves are
+  shut, fall and hang down; of the other, the whole branches fall to the
+  ground, if the Sun shine very warm, upon the first taking off the Glass,
+  which I therefore call the <i>humble Plant</i>.</p>
+
+  <p>The other two, which do never fall, nor do any of their branches flagg
+  and hang down, shut not their leaves, but upon somewhat a hard stroke;
+  the stalks seem to grow up from a root, and appear more
+  <i>herbaceous</i>, they are round and smooth, without any prickle, the
+  Sprouts from them have several pairs of sprigs, with much less leaves
+  then the other on them, and have on each sprig generally seventeen
+  pair.</p>
+
+  <p>Upon touching any of the sprigs with leaves on, all the leaves on that
+  sprig contracting themselves by pairs, joyned their upper superficies
+  close together.</p>
+
+  <p>Upon the dropping a drop of <i>Aqua fortis</i> on the sprig betwixt
+  the leaves, <i>ff</i> all the leaves above shut presently, those below by
+  pairs successively after, and by the lower leaves of the other branches,
+  <i>ll</i>, <i>kk</i>, &amp;c. and so every pair successively, with some
+  little distance of time betwixt, to the top of each sprig, and so they
+  continu'd shut all the time we were there. But I returning the next day,
+  and several days since, found all the leaves dilated again on two of the
+  sprigs; but from <i>ff</i>, where the <i>Aqua fortis</i> had dropped
+  upwards, dead and withered; but those below on the same sprig, green, and
+  closing upon the touch, and are so to this day, <i>August</i> 14.</p>
+
+  <p>With a pair of Scissers, as suddenly as it could be done, one of the
+  leaves <i>bb</i> was clipped off in the middle, upon which that pair, and
+  the pair above, closed presently, after a little interval, <i>dd</i>,
+  then <i>ee</i>, and so the rest of the pairs, to the bottom of the sprig,
+  and then the motion began in the lower pairs, <i>ll</i>, on the other
+  sprigs, and so shut them by pairs upwards, though not with such distinct
+  distances.</p>
+
+  <p>Under a pretty large branch with its sprigs on, there lying a large
+  Shell betwixt two and three Inches below it, there was rubbed on a strong
+  sented oyl, after a little time all the leaves on that sprig were shut,
+  and so they continued all the time of our stay there, but at my returne
+  the next day, I found the position of the Shell alter'd, and the leaves
+  expanded as before, and closing upon the touch.</p>
+
+  <p>Upon the application of the Sun-beams by a Burning-glass, the more
+  <i>humble Plant</i> fell, the other shut their leaves.</p>
+
+  <p>We could not so apply the smoak of <i>Sulpher</i>, as to have any
+  visible effect from that, at two or three times trial; but on another
+  trial, the smoak touching the leaves, it succeeded.</p>
+
+  <p>The <i>humble Plant</i> fell upon taking off the Glass wherewith it
+  was covered.</p>
+
+  <p>Cutting off one of the little Sprouts, two or three drops of liquor
+  were thrust out of the part from whence that was cut, very cleer, and
+  pellucid, of a bright greenish colour, tasting at first a little
+  bitterish, but after leaving a licorish-like taste in my mouth.</p>
+
+  <p>Since, going two or three times when it was cold, I took the Glasses
+  from the more <i>humble Plant</i>, and it did not fall as formerly, but
+  shut its leaves onely. But coming afterwards, when the Sun shone very
+  warm, as soon as it was taken off, it fell as before.</p>
+
+  <p>Since I pluck'd off another sprig, whose leaves were all shut, and had
+  been so some time, thinking to observe the liquor should come from that I
+  had broken off, but finding none, though with pressing, to come, I, as
+  dexterously as I could, pull'd off one whose leaves were expanded, and
+  then had upon the shutting of the leaves, a little of the mention'd
+  liquor, from the end of the sprig I had broken from the Plant. And this
+  twice successively, as often almost as I durst rob the Plant.</p>
+
+  <p>But my curiosity carrying me yet further, I cut off one of the harder
+  branches of the stronger Plant, and there came of the
+  liquor, both from that I had cut, and that I had cut it from, without
+  pressure.</p>
+
+  <p>Which made me think, that the motion of this Plant upon touching,
+  might be from this, that there being a constant <i>intercourse</i>
+  betwixt every part of this Plant and its root, either by a
+  <i>circulation</i> of this liquor, or a constant pressing of the subtiler
+  parts of it to every extremity of the Plant. Upon every pressure, from
+  whatsoever it proceeds, greater then that which keeps it up, the subtile
+  parts of this liquor are thrust downwards, towards its
+  <i>articulations</i> of the leaves, where, not having room presently to
+  get into the sprig, the little round <i>pedunculus</i>, from whence the
+  <i>Spine</i> and those oblique <i>Fibres</i> I mentioned rise, being
+  dilated, the <i>Spine</i> and <i>Fibres</i> (being continued from it)
+  must be contracted and shortned, and so draw the leaf upwards to joyn
+  with its fellow in the same condition with it self, where, being closed,
+  they are held together by the implications of the little whitish hair, as
+  well as by the still retreating liquor, which distending the
+  <i>Fibres</i> that are continued lower to the branch and root, shorten
+  them above; and when the liquor is so much forced from the Sprout, whose
+  <i>Fibres</i> are yet tender, and not able to support themselves, but by
+  that tensness which the liquor filling their <i>interstices</i> gives
+  them, the Sprout hangs and flags.</p>
+
+  <p>But, perhaps, he that had the ability and leisure to give you the
+  exact <i>Anatomy</i> of this pretty Plant, to shew you its <i>Fibres</i>,
+  and visible <i>Canales</i>, through which this fine liquor circulateth,
+  or is moved, and had the faculty of better and more copiously expressing
+  his Observations and conceptions, such a one would easily from the motion
+  of this liquor, solve all the <i>Phænomena</i>, and would not fear to
+  affirm, that it is no obscure sensation this Plant hath. But I have said
+  too much, I humbly submit, and am ready to stand corrected.</p>
+
+</blockquote>
+
+  <p>I have not yet made so full and satisfactory Observations as I desire
+  on this Plant, which seems to be a Subject that will afford abundance of
+  information. But as farr as I have had
+  opportunity to examine it, I have discovered with my <i>Microscope</i>
+  very curious structures and contrivances; but designing much more
+  accurate examinations and trials, both with my <i>Microscope</i>, and
+  otherwise, as soon as the season will permit, I shall not till then add
+  any thing of what I have already taken notice of; but as farr as I have
+  yet observ'd, I judge the motion of it to proceed from causes very
+  differing from those by which Gut-strings, or Lute-strings, the beard of
+  a wilde <i>Oat</i>, or the beard of the Seeds of <i>Geranium</i>,
+  <i>Mosscatum</i>, or <i>Musk-grass</i> and other kinds of
+  <i>Cranes-bill</i>, move themselves. Of which I shall add more in the
+  subsequent Observations on those bodies.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXIX" id="obsXIX">XIX</a>. <i>Of a </i>Plant<i> growing in the blighted or yellow specks
+of </i>Damask-rose-leaves<i>, </i>Bramble-leaves<i>, and some other kind
+of leaves.</i></h3>
+
+  <p>I have for several years together, in the Moneths of <i>June</i>,
+  <i>July</i>, <i>August</i>, and <i>September</i> (when any of the green
+  leaves of <i>Roses</i> begin to dry and grow yellow) observ'd many of
+  them, especially the leaves of the old shrubs of <i>Damask Roses</i>, all
+  bespecked with yellow stains; and the undersides just against them, to
+  have little yellow hillocks of a gummous substance, and several of them
+  to have small black spots in the midst of those yellow ones, which, to
+  the naked eye, appear'd no bigger then the point of a Pin, or the
+  smallest black spot or tittle of Ink one is able to make with a very
+  sharp pointed Pen.</p>
+
+<span class="sidenote">
+<a href="images/scheme-12.png" target="_blank"><i>Schem.</i> 12.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>Examining these with a <i>Microscope,</i> I was able plainly to
+  distinguish, up and down the surface, several small yellow knobs, of a
+  kind of yellowish red gummy substance, out of which I perceiv'd there
+  sprung multitudes of little cases or black bodies like Seed-cods, and
+  those of them that were quite without the hillock of Gumm, disclos'd
+  themselves to grow out of it with a small Straw-colour'd and transparent
+  stem, the which seed and stem appear'd very like those of common Moss
+  (which I elsewhere describe) but that they were abundantly less, many
+  hundreds of them being not able to equalize one single seed Cod of
+  Moss.</p>
+
+  <p>I have often doubted whether they were the seed Cods of some little
+  Plant, or some kind of small Buds, or the Eggs of some very small Insect,
+  they appear'd of a dark brownish red, some almost quite black, and of a
+  Figure much resembling the seed-cod of Moss, but their stalks on which
+  they grew were of a very fine transparent substance, almost like the
+  stalk of mould, but that they seem'd somewhat more yellow.</p>
+
+  <p>That which makes me to suppose them to be Vegetables, is for that I
+  perceiv'd many of those hillocks bare or destitute, as if those bodies
+  lay yet conceal'd, as G. In others of them, they were just springing out
+  of their gummy hillocks, which all seem'd to shoot directly outwards, as
+  at A. In others, as at B, I found them just gotten out, with very little
+  or no stalk, and the Cods of an indifferent cize; but in
+  others, as C, I found them begin to have little short stalks, or stems;
+  in others, as D, those stems were grown bigger, and larger; and in
+  others, as at E, F, H, I, K, L, <i>&amp;c.</i> those stems and Cods were
+  grown a great deal bigger, and the stalks were more bulky about the root,
+  and very much taper'd towards the top, as at F and L is most visible.</p>
+
+  <p>I did not find that any of them had any seed in them, or that any of
+  them were hollow, but as they grew bigger and bigger, I found those heads
+  or Cods begin to turn their tops towards their roots, in the same manner
+  as I had observ'd that of Moss to do; so that in all likelihood, Nature
+  did intend in that posture, what she does in the like seed-cods of
+  greater bulk, that is, that the seed, when ripe, should be shaken out and
+  dispersed at the end of it, as we find in Columbine Cods, and the
+  like.</p>
+
+  <p>The whole Oval OOOO in the second <i>Figure</i> of the 12.
+  <i>Scheme</i> represents a small part of a Rose leaf, about the bigness
+  of the little Oval in the hillock, C, marked with the Figure X. in which
+  I have not particularly observ'd all the other forms of the surface of
+  the Rose-leaf, as being little to my present purpose.</p>
+
+  <p>Now, if these Cods have a seed in them so proportion'd to the Cod, as
+  thole of <i>Pinks</i>, and <i>Carnations</i>, and <i>Columbines</i>, and
+  the like, how unimaginably small must each of those seeds necessarily be,
+  for the whole length of one of the largest of those Cods was not 1/500
+  part of an Inch; some not above 1/1000, and therefore certainly, very
+  many thousand of them would be unable to make a bulk that should be
+  visible to the naked eye; and if each of these contain the Rudiments of a
+  young Plant of the same kind, what must we say of the pores and
+  constituent parts of that?</p>
+
+  <p>The generation of this Plant seems in part, ascribable to a kind of
+  <i>Mildew</i> or <i>Blight</i>, whereby the parts of the leaves grow
+  scabby, or putrify'd, as it were, so as that the moisture breaks out in
+  little scabs or spots, which, as I said before, look like little knobs of
+  a red gummous substance.</p>
+
+  <p>From this putrify'd scabb breaks out this little Vegetable; which may
+  be somewhat like a <i>Mould</i> or <i>Moss</i>; and may have its
+  <i>equivocal</i> generation much after the same manner as I have supposed
+  <i>Moss</i> or <i>Mould</i> to have, and to be a more simple and
+  uncompounded kind of vegetation, which is set a moving by the
+  <i>putrifactive</i> and <i>fermentative</i> heat, joyn'd with that of the
+  ambient aerial, when (by the putrifaction and decay of some other parts
+  of the vegetable, that for a while staid its progress) it is unfetter'd
+  and left at liberty to move in its former course, but by reason of its
+  <i>regulators</i>, moves and acts after quite another manner then it did
+  when a <i>coagent</i> in the more compounded <i>machine</i> of the more
+  perfect Vegetable.</p>
+
+  <p>And from this very same Principle, I imagine the <i>Misleto</i> of
+  Oaks, Thorns, Appletrees, and other Trees, to have its original: It
+  seldom or never growing on any of those Trees, till they begin to wax
+  decrepid, and decay with age, and are pester'd with many other
+  infirmities.</p>
+
+  <p>Hither also may be referr'd those multitudes and varieties of
+  <i>Mushroms</i>, such as that, call'd <i>Jews-ears</i>, all sorts of
+  <i>gray</i> and <i>green</i> Mosses, &amp;c. which infest
+  all kind of Trees, shrubs, and the like, especially when they come to any
+  bigness. And this we see to be very much the method of Nature throughout
+  its operations, <i>putrifactive Vegetables</i> very often producing a
+  Vegetable of a much less compounded nature, and of a much inferiour
+  tribe; and <i>putrefactive</i> animal substances degenerating into some
+  kind of animal production of a much inferiour rank, and of a more simple
+  nature.</p>
+
+  <p>Thus we find the humours and substances of the body, upon
+  <i>putrifaction</i>, to produce strange kinds of moving Vermine: <i>the
+  putrifaction</i> of the slimes and juices of the Stomack and Guts,
+  produce Worms almost like Earth-worms, the Wheals in childrens hands
+  produce a little Worm, call'd a <i>Wheal-worm</i>: The bloud and milk,
+  and other humours, produce other kinds of Worms, at least, if we may
+  believe what is deliver'd to us by very famous Authors; though, I
+  confess, I have not yet been able to discover such my self.</p>
+
+  <p>And whereas it may seem strange that <i>Vinegar</i>, <i>Meal</i>,
+  musty <i>Casks</i>, &amp;c. are observ'd to breed their differing kinds
+  of Insects, or living creatures, whereas they being Vegetable substances,
+  seem to be of an inferiour kind, and so unable to produce a creature more
+  noble, or of a more compounded nature then they themselves are of, and so
+  without some concurrent seminal principle, may be thought utterly unfit
+  for such an operation; I must add, that we cannot presently positively
+  say, there are no animal substances, either mediately, as by the soil or
+  fatning of the Plant from whence they sprung, or more immediately, by the
+  real mixture or composition of such substances, join'd with them; or
+  perchance some kind of Insect, in such places where such kind of
+  <i>putrifying</i> or <i>fermenting</i> bodies are, may, by a certain
+  instinct of nature, eject some sort of seminal principle, which
+  cooperating with various kinds of <i>putrifying</i> substances, may
+  produce various kinds of Insects, or Animate bodies: For we find in most
+  sorts of those lower degrees of Animate bodies, that the
+  <i>putrifying</i> substances on which these Eggs, Seeds, or seminal
+  principles are cast by the Insect, become, as it were, the
+  <i>Matrices</i> or Wombs that conduce very much to their generation, and
+  may perchance also to their variation and alteration, much after the same
+  manner, as, by strange and unnatural copulations, several new kinds of
+  Animals are produc'd, as <i>Mules</i>, and the like, which are usually
+  call'd Monstrous, because a little unusual, though many of them have all
+  their principal parts as perfectly shap'd and adapted for their peculiar
+  uses, as any of the most perfect Animals. If therefore the
+  <i>putrifying</i> body, on which any kind of seminal or vital principle
+  chances to be cast, become somewhat more then meerly a nursing and
+  fostering helper in the generation and production of any kind of Animate
+  body, the more neer it approaches the true nature of a Womb, the more
+  power will it have on the by-blow it incloses. But of this somewhat more
+  in the description of the <i>Water-gnat</i>. Perhaps some more accurate
+  Enquiries and Observations about these matters might bring the Question
+  to some certainty, which would be of no small concern in Natural
+  Philosophy.</p>
+
+  <p>But that <i>putrifying</i> animal substances may produce animals of an
+  inferior kind, I see not any so very great a
+  difficulty, but that one may, without much absurdity, admit: For as there
+  may be multitudes of contrivances that go to the making up of one
+  compleat Animate body; so, That some of those <i>coadjutors</i>, in the
+  perfect existence and life of it, may be vitiated, and the life of the
+  whole destroyed, and yet several of the constituting contrivances remain
+  intire, I cannot think it beyond imagination or possibility; no more then
+  that a like accidental process, as I have elswhere hinted, may also be
+  supposed to explicate the method of Nature in the <i>Metamorphosis</i> of
+  Plants. And though the difference between a Plant and an Animal be very
+  great, yet I have not hitherto met with any so <i>cogent</i> an Argument,
+  as to make me positive in affirming these two to be altogether
+  <i>Heterogeneous</i> and of quite differing kinds of Nature: And besides,
+  as there are many <i>Zoophyts</i>, and sensitive Plants (divers of which
+  I have seen, which are of a middle nature, and seem to be Natures
+  transition from one degree to another, which may be observ'd in all her
+  other passages, wherein she is very seldom observ'd to leap from one step
+  to another) so have we, in some Authors, Instances of Plants turning into
+  Animals, and Animals into Plants, and the like; and some other very
+  strange (because unheeded) proceedings of Nature; something of which kind
+  may be met with, in the description of the <i>Water-Gnat</i>, though it
+  be not altogether so direct to the present purpose.</p>
+
+  <p>But to refer this Discourse of Animals to their proper places, I shall
+  add, that though one should suppose, or it should be prov'd by
+  Observations; that several of these kinds of Plants are accidentally
+  produc'd by a casual <i>purifaction</i>, I see not any great reason to
+  question, but that, notwithstanding its own production was as 'twere
+  casual, yet it may germinate and produce seed, and by it propagate its
+  own, that is, a new Species. For we do not know, but that the Omnipotent
+  and All-wise Creator might as directly design the structure of such a
+  Vegetable, or such an Animal to be produc'd out of such or such a
+  <i>putrifaction</i> or change of this or that body, towards the
+  constitution or structure of which, he knew it necessary, or thought it
+  fit to make it an ingredient; as that the digestion or moderate heating
+  of an Egg, either by the Female, or the Sun, or the heat of the Fire, or
+  the like, should produce this or that Bird; or that <i>Putrifactive</i>
+  and warm steams should, out of the blowings, as they call them, that is,
+  the Eggs of a Flie, produce a living Magot, and that, by degrees, be
+  turn'd into an <i>Aurelia</i>, and that, by a longer and a proportion'd
+  heat, be <i>transmuted</i> into a Fly. Nor need we therefore to suppose
+  it the more imperfect in its kind, then the more compounded Vegetable or
+  Animal of which it is a part; for he might as compleatly furnish it with
+  all kinds of contrivances necessary for its own existence, and the
+  propagation of its own Species, and yet make it a part of a more
+  compounded body: as a Clock-maker might make a Set of Chimes to be a part
+  of a Clock, and yet, when the watch part or striking part are taken away,
+  and the hindrances of its motion remov'd, this chiming part may go as
+  accurately, and strike its tune as exactly, as if it were still a part of
+  the compounded <i>Automaton</i>. So, though the original cause, or
+  seminal principle from which this minute
+  Plant on Rose leaves did spring; were, before the corruption caus'd by
+  the Mill-dew, a component part of the leaf on which it grew, and did
+  serve as a <i>coagent</i> in the production and constitution of it, yet
+  might it be so consummate, as to produce a seed which might have a power
+  of propagating the same species: the works of the Creator seeming of such
+  an excellency, that though they are unable to help to the perfecting of
+  the more compounded existence of the greater Plant or Animal, they may
+  have notwithstanding an ability of acting singly upon their own internal
+  principle, so as to produce a Vegetable body, though of a less compounded
+  nature, and to proceed so farr in the method of other Vegetables, as to
+  bear flowers and seeds, which may be capabale of propagating the like. So
+  that the little cases which appear to grow on the top of the slender
+  stalks, may, for ought I know, though I should suppose them to spring
+  from the perverting of the usual course of the parent Vegetable, contain
+  a seed, which, being scatter'd on other leaves of the same Plant, may
+  produce a Plant of much the same kind.</p>
+
+  <p>Nor are Damask-Rose leaves the onely leaves that produce these kinds
+  of Vegetable sproutings; for I have observ'd them also in several other
+  kinds of Rose leaves, and on the leaves of several sorts of Briers, and
+  on Bramble leaves they are oftentimes to be found in very great clusters;
+  so that I have found in one cluster, three, four, or five hundred of
+  them, making a very conspicuous black spot or scab on the back side of
+  the leaf.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXX" id="obsXX">XX</a>. <i>Of </i>blue Mould<i>, and of the first Principles of Vegetation
+arising from </i>Putrefaction<i>.</i></h3>
+
+  <p>The Blue and White and several kinds of hairy mouldy spots, which are
+  observable upon divers kinds of <i>putrify'd</i> bodies, whether Animal
+  substances, or Vegetable, such as the skin, raw or dress'd, flesh, bloud,
+  humours, milk, green Cheese, <i>&amp;c.</i> or rotten sappy Wood, or
+  Herbs, Leaves, Barks, Roots, <i>&amp;c.</i> of Plants, are all of them
+  nothing else but several kinds of small and variously figur'd Mushroms,
+  which, from convenient materials in those <i>putrifying</i> bodies, are,
+  by the concurrent heat of the Air, excited to a certain kind of
+  vegetation, which will not be unworthy our more serious speculation and
+  examination, as I shall by and by shew. But, first, I must premise a
+  short description of this <i>Specimen</i>, which I have added of this
+<span class="sidenote">
+<a href="images/scheme-12.png" target="_blank"><i>Schem.</i> 12.</a><br /><i>Fig.</i> 1.
+</span>
+  Tribe, in the first Figure of the XII. <i>Scheme</i>, which is nothing
+  else but the appearance of a small white spot of hairy mould, multitudes
+  of which I found to bespeck &amp; whiten over the red covers of a small
+  book, which, it seems, were of Sheeps skin, that being more apt to gather
+  mould, even in a dry and clean room, then other leathers. These spots
+  appear'd, through a good <i>Microscope</i>, to be a very pretty shap'd
+  Vegetative body, which, from almost the same part of the Leather, shot
+  out multitudes of small long cylindrical
+  and transparent stalks, not exactly streight, but a little bended with
+  the weight of a round and white knob that grew on the top of each of
+  them; many of these knobs I observ'd to be very round, and of a smooth
+  surface, such as A, A, <i>&amp;c.</i> others smooth likewise, but a little
+  oblong, as B; several of them a little broken, or cloven with chops at
+  the top, as C; others flitter'd as 'twere, or flown all to pieces, as D, D.
+  The whole substance of these pretty bodies was of a very tender
+  constitution, much like the substance of the softer kind of common white
+  Mushroms, for by touching them with a Pin, I found them to be brused and
+  torn; they seem'd each of them to have a distinct root of their own; for
+  though they grew neer together in a cluster, yet I could perceive each
+  stem to rise out of a distinct part or pore of the Leather; some of these
+  were small and short, as seeming to have been but newly sprung up, of
+  these the balls were for the most part round, others were bigger, and
+  taller, as being perhaps of a longer growth, and of these, for the most
+  part, the heads were broken, and some much wasted, as E; what these heads
+  contain'd I could not perceive; whether they were knobs and flowers, or
+  seed cases, I am not able to say, but they seem'd most likely to be of
+  the same nature with those that grow on Mushroms, which they did, some of
+  them, not a little resemble.</p>
+
+  <p>Both their smell and taste, which are active enough to make a sensible
+  impression upon those organs, are unpleasant and noisome.</p>
+
+  <p>I could not find that they would so quickly be destroy'd by the actual
+  flame of a Candle, as at first sight of them I conceived they would be,
+  but they remain'd intire after I had past that part of the Leather on
+  which they stuck three or four times through the flame of a Candle; so
+  that, it seems they are not very apt to take fire, no more then the
+  common white Mushroms are when they are sappy.</p>
+
+  <p>There are a multitude of other shapes, of which these
+  <i>Microscopical</i> Mushroms are figur'd, which would have been a long
+  Work to have described, and would not have suited so well with my design
+  in this Treatise, onely, amongst the rest, I must not forget to take
+  notice of one that was a little like to, or resembled, a Spunge,
+  consisting of a multitude of little Ramifications almost as that body
+  does, which indeed seems to be a kind of Water-Mushrom, of a very pretty
+  texture, as I else-where manifest. And a second, which I must not omit,
+  because often mingled, and neer adjoining to these I have describ'd, and
+  this appear'd much like a Thicket of bushes, or brambles, very much
+  branch'd, and extended, some of them, to a great length, in proportion to
+  their Diameter, like creeping brambles.</p>
+
+  <p>The manner of the growth and formation of this kind of Vegetable, is
+  the third head of Enquiry, which, had I time, I should follow: the figure
+  and method of Generation in this concrete seeming to me, next after the
+  Enquiry into the formation, figuration; or chrystalization of Salts, to
+  be the most simple, plain, and easie; and it seems to be a <i>medium</i>
+  through which he must necessarily pass, that would with any likelihood
+  investigate the <i>forma informans</i> of Vegetables: for as I think that
+  he shall find it a very difficult task, who undertakes to discover the
+  form of Saline crystallizations, without the consideration
+  and prescience of the nature and reason of a Globular form, and as
+  difficult to explicate this configuration of Mushroms, without the
+  previous consideration of the form of Salts; so will the enquiry into the
+  forms of Vegetables be no less, if not much more difficult, without the
+  fore-knowledge of the forms of Mushroms, these several Enquiries having
+  no less dependance one upon another then any select number of
+  Propositions in Mathematical Elements may be made to have.</p>
+
+  <p>Nor do I imagine that the skips from the one to another will be found
+  very great, if beginning from fluidity, or body without any form, we
+  descend gradually, till we arrive at the highest form of a bruite
+  Animal's Soul, making the steps or foundations of our Enquiry,
+  <i>Fluidity</i>, <i>Orbiculation</i>, <i>Fixation</i>,
+  <i>Angulization</i>, or <i>Crystallization Germination</i> or
+  <i>Ebullition</i>, <i>Vegetation</i>, <i>Plantanimation</i>,
+  <i>Animation</i>, <i>Sensation</i>, <i>Imagination</i>.</p>
+
+  <p>Now, that we may the better proceed in our Enquiry, It will be
+  requisite to consider:</p>
+
+  <p>First, that Mould and Mushroms require no seminal property, but the
+  former may be produc'd at any time from any kind of <i>putrifying</i>
+  Animal, or Vegetable Substance, as Flesh, <i>&amp;c.</i> kept moist and
+  warm, and the latter, if what <i>Mathiolus</i> relates be true, of making
+  them by Art, are as much within our command, of which Matter take the
+  <i>Epitomie</i> which Mr. <i>Parkinson</i> has deliver'd in his
+  <i>Herbal</i>, in his Chapter of <i>Mushroms</i>, because I have not
+  <i>Mathiolus</i> now by me: <i>Unto these Mushroms</i> (saith he) <i>may
+  also be adjoyn'd those which are made of Art (whereof </i>Mathiolus<i>
+  makes mention) that grow naturally among certain stones in </i>Naples<i>,
+  and that the stones being digg'd up, and carried to </i>Rome<i>, and
+  other places, where they set them in their Wine Cellars, covering them
+  with a little Earth, and sprinkling a little warm water thereon, would
+  within four days produce Mushroms fit to be eaten, at what time one will:
+  As also that Mushroms may be made to grow at the foot of a wilde
+  </i>Poplar Tree<i>, within four days after, warm water wherein some
+  leaves have been dissolv'd shall be pour'd into the Root (which must be
+  slit) and the stock above ground.</i></p>
+
+  <p>Next, that as Mushroms may be generated without seed, so does it not
+  appear that they have any such thing as seed in any part of them; for
+  having considered several kinds of them, I could never find any thing in
+  them that I could with any probability ghess to be the seed of it, so
+  that it does not as yet appear (that I know of) that Mushroms may be
+  generated from a seed, but they rather seem to depend merely upon a
+  convenient constitution of the matter out of which they are made, and a
+  concurrence of either natural or artificial heat.</p>
+
+  <p>Thirdly, that by several bodies (as Salts and Metals both in Water and
+  in the air, and by several kinds of sublimations in the Air) actuated and
+  guided with a congruous heat, there may be produc'd several kinds of
+  bodies as curiously, if not of a more compos'd Figure; several kinds of
+  rising or Ebulliating Figures seem to manifest; as witness the shooting
+  in the Rectification of spirits of <i>Urine</i>, <i>Hart-horn</i>,
+  <i>Bloud</i>, &amp;c. witness also the curious branches of evaporated
+  dissolutions, some of them against the sides
+  of the containing Jar: others standing up, or growing an end, out of the
+  bottom, of which I have taken notice of a very great variety. But above
+  all the rest, it is a very pretty kind of Germination which is afforded
+  us in the Silver Tree, the manner of making which with Mercury and
+  Silver, is well known to the Chymists, in which there is an Ebullition or
+  Germination, very much like this of Mushroms, if I have been rightly
+  inform'd of it.</p>
+
+  <p>Fourthly, I have very often taken notice of, and also observ'd with a
+  <i>Microscope</i>, certain excrescencies or Ebullitions in the snuff of a
+  Candle, which, partly from the sticking of the smoaky particles as they
+  are carryed upwards by the current of the rarify'd Air and flame, and
+  partly also from a kind of Germination or Ebullition of some actuated
+  unctuous parts which creep along and filter through some small string of
+  the Week, are formed into pretty round and uniform heads, very much
+  resembling the form of hooded Mushroms, which, being by any means expos'd
+  to the fresh Air, or that air which encompasses the flame, they are
+  presently lick'd up and devour'd by it, and vanish.</p>
+
+  <p>The reason of which <i>Phænomenon</i> seems to me, to be no other then
+  this:</p>
+
+  <p>That when a convenient thread of the Week is so bent out by the sides
+  of the snuff that are about half an Inch or more, remov'd above the
+  bottom, or lowest part of the flame, and that this part be wholly
+  included in the flame; the Oyl (for the reason of filtration, which I
+  have elsewhere rendred) being continualy driven up the snuff is driven
+  likewise into this ragged bended-end, and this being remov'd a good
+  distance, as half an Inch or more, above the bottom of the flame, the
+  parts of the air that passes by it, are already, almost satiated with the
+  dissolution of the boiling unctuous steams that issued out below, and
+  therefore are not onely glutted, that is, can dissolve no more then what
+  they are already acting upon, but they carry up with them abundance of
+  unctuous and sooty particles, which meeting with that rag of the Week,
+  that is plentifully fill'd with Oyl, and onely spends it as fast as it
+  evaporates, and not at all by dissolution or burning, by means of these
+  steamy parts of the filterated Oyl issuing out at the sides of this ragg,
+  and being inclos'd with an air that is already satiated and cannot prey
+  upon them nor burn them, the ascending sooty particles are stay'd about
+  it and fix'd, so as that about the end of that ragg or filament of the
+  snuff, whence the greatest part of the steams issue, there is conglobated
+  or fix'd a round and pretty uniform cap, much resembling the head of a
+  Mushrom, which, if it be of any great bigness, you may observe that its
+  underside will be bigger then that which is above the ragg or stem of it;
+  for the Oyl that is brought into it by filtration, being by the bulk of
+  the cap a little shelter'd from the heat of the flame, does by that means
+  issue as much out beneath from the stalk or downwards, as it does
+  upwards, and by reason of the great access of the adventitious smoak from
+  beneath, it increases most that way. That this may be the true reason of
+  this <i>Phænomenon</i>, I could produce many Arguments and Experiments to
+  make it probable: As,</p>
+
+  <p>First, that the <i>Filtration</i> carries the Oyl to the top of the
+  Week, at least as high as these raggs, is visible to one
+  that will observe the snuff of a burning Candle with a <i>Microscope</i>,
+  where he may see an Ebullition or bubbling of the Oyl, as high as the
+  snuff looks black.</p>
+
+  <p>Next, that it does steam away more then burn; I could tell you of the
+  dim burning of a Candle, the longer the snuff be which arises from the
+  abundance of vapours out of the higher parts of it.</p>
+
+  <p>And, thirdly, that in the middle of the flame of the Candle, neer the
+  top of the snuff, the fire or dissolving principle is nothing neer so
+  strong, as neer the bottom and out edges of the flame, which may be
+  observ'd by the burning asunder of a thread, that will first break in
+  those parts that the edges of the flame touch, and not in the middle.</p>
+
+  <p>And I could add several Observables that I have taken notice of in the
+  flame of a Lamp actuated with Bellows, and very many others that confirm
+  me in my opinion, but that it is not so much to my present purpose, which
+  is onely to consider this concreet in the snuff of a Candle, so farr as
+  it has any resemblance of a Mushrom, to the consideration of which, that
+  I may return, I say, we may also observe:</p>
+
+  <p>In the fifth place, that the droppings or trillings of Lapidescent
+  waters in Vaults under ground, seem to constitute a kind of
+  <i>petrify'd</i> body, form'd almost like some kind of Mushroms inverted,
+  in so much that I have seen some knobb'd a little at the lower end,
+  though for the most part, indeed they are otherwise shap'd, and taper'd
+  towards the end; the generation of which seems to be from no other reason
+  but this, that the water by soaking through the earth and Lime (for I
+  ghess that substance to add much to it <i>petrifying</i> quality) does so
+  impregnate it self with stony particles, that hanging in drops in the
+  roof of the Vault, by reason that the soaking of the water is but slow,
+  it becomes expos'd to the Air, and thereby the outward part of the drop
+  by degrees grows hard, by reason that the water gradually evaporating the
+  stony particles neer the outsides of the drop begin to touch, and by
+  degrees, to dry and grow closer together, and at length constitute a
+  crust or shell about the drop; and this soaking by degrees, being more
+  and more supply'd, the drop grows longer and longer, and the sides harden
+  thicker and thicker into a Quill or Cane, and at length, that hollow or
+  pith becomes almost stop'd up, and solid: afterwards the soaking of the
+  <i>petrifying</i> water, finding no longer a passage through the middle,
+  bursts out, and trickles down the outside, and as the water evaporates,
+  leaves new superinduc'd shells, which more and more swell the bulk of
+  those Iceicles, and because of the great supply from the Vault, of
+  <i>petrifying</i> wafer, those bodies grow bigger and bigger next to the
+  Vault, and taper or sharpen towards the point; for the access from the
+  arch of the Vault being but very slow, and consequently the water being
+  spread very thinly over the surface of the Iceicle, the water begins to
+  settle before it can reach to the bottom, or corner end of it; whence, if
+  you break one of these, you would almost imagine it a stick of Wood
+  <i>petrify'd</i>, it having so pretty a resemblance of pith and grain,
+  and if you look on the outside of a piece, or of one whole, you would
+  think no less, both from its vegetable roundness and
+  tapering form; but whereas all Vegetables are observ'd to shoot and grow
+  perpendicularly upwards, this does shoot or propend directly
+  downwards.</p>
+
+  <p>By which last Observables, we see that there may be a very pretty body
+  shap'd and concreeted by Mechanical principles, without the least shew or
+  probability of any other seminal <i>formatrix</i>.</p>
+
+  <p>And since we find that the great reason of the <i>Phænomena</i> of
+  this pretty <i>petrifaction</i>, are to be reduc'd from the gravity of a
+  fluid and pretty volatil body impregnated with stony particles, why may
+  not the <i>Phænomena</i> of Ebullition or Germination be in part possibly
+  enough deduc'd from the levity of an impregnated liquor, which therefore
+  perpendicularly ascending by degrees, evaporates and leaves the more
+  solid and fix'd parts behind in the form of a Mushrom, which is yet
+  further diversify'd and specificated by the forms of the parts that
+  impregnated the liquor, and compose or help to constitute the
+  Mushrom.</p>
+
+  <p>That the foremention'd Figures of growing Salts, and the Silver Tree,
+  are from this principle, I could very easily manifest, but that I have
+  not now a convenient opportunity of following it, nor have I made a
+  sufficient number of Experiments and Observations to propound, explicate,
+  and prove so usefull a <i>Theory</i> as this of Mushroms: for, though the
+  contrary principle to that of <i>petrify'd</i> Iceicles may be in part a
+  cause, yet I cannot but think, that there is somewhat a more complicated
+  caufe, though yet Mechanical, and possible to be explain'd.</p>
+
+  <p>We therefore have further to enquire of it, what makes it to be such a
+  liquor, and to ascend, whether the heat of the Sun and Air, or whether
+  that <i>firmentiation</i> and <i>putrifaction</i>, or both together; as
+  also whether there be not a third or fourth; whether a Saline principle
+  be not a considerable agent in this business also as well as heat;
+  whether also a fixation, precipitation or settling of certain parts out
+  of the aerial menstruum may not be also a considerable coadjutor in the
+  business. Since we find that many pretty beards <i>stiriæ</i> of the
+  particles of Silver may be precipitated upon a piece of Brass put into a
+  <i>solution</i> of Silver very much diluted with fair water, which look
+  not unlike a kind of mould or hoar upon that piece of metal; and the hoar
+  frost looks like a kind of mould; and whether there may not be several
+  others that do concurr to the production of a Mushrom, having not yet had
+  sufficient time to prosecute according to my desires, I must referr this
+  to a better opportunity of my own, or leave and recommend it to the more
+  diligent enquiry and examination of such as can be masters both of
+  leisure and conveniencies for such an Enquiry.</p>
+
+  <p>And in the mean time, I must conclude, that as far as I have been able
+  to look into the nature of this Primary kind of life and vegetation, I
+  cannot find the least probable argument to perswade me there is any other
+  concurrent cause then such as is purely Mechanical, and that the effects
+  or productions are as necessary upon the concurrence of those causes as
+  that a Ship, when the Sails are hoist up, and the Rudder is set to such a
+  position, should, when the Wind blows, be mov'd in such a way or course
+  to that or t'other place; Or, as that the
+  brused Watch, which I mention in the description of Moss, should, when
+  those parts which hindred its motion were fallen away, begin to move, but
+  after quite another manner then it did before.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXI" id="obsXXI">XXI</a>. <i>Of </i>Moss<i>, and several other small-vegetative Substances.</i></h3>
+
+  <p>Moss is a Plant, that the wisest of Kings thought neither unworthy his
+  speculation, nor his Pen, and though amongst Plants it be in bulk one of
+  the smallest, yet it is not the least considerable: For, as to its shape,
+  it may compare for the beauty of it with any Plant that grows, and bears
+  a much bigger breadth; it has a root almost like a seedy Parsnep,
+  furnish'd with small strings and suckers, which are all of them finely
+  branch'd, like those of the roots of much bigger Vegetables; out of this
+  springs the stem or body of the Plant, which is somewhat
+  <i>Quadrangular</i>, rather then <i>Cylindrical</i>, most curiously
+  <i>fluted</i> or lining with small creases, which run, for the most part,
+  <i>parallel</i> the whole stem; on the sides of this are close and thick
+  set, a multitude of fair, large, well-shap'd leaves, some of them of a
+  rounder, others of a longer shape, according as they are younger or older
+  when pluck'd; as I ghess by this, that those Plants that had the stalks
+  growing from the top of them, had their leaves of a much longer shape,
+  all the surface of each side of which, is curiously cover'd with a
+  multitude of little oblong transparent bodies, in the manner as you see
+<span class="sidenote">
+<a href="images/scheme-13.png" target="_blank"><i>Schem.</i> 13.</a><br /><i>Fig.</i> B.
+</span>
+  it express'd in the leaf B, in the XIII. <i>Scheme</i>.</p>
+
+  <p>This Plant, when young and springing up, does much resemble a
+  Housleek, having thick leaves, almost like that, and seems to be somwhat
+  of kin to it in other particulars; also from the top of the leaves, there
+  shoots out a small white and transparent hair, or thorn: This stem, in
+  time, come to shoot out into a long, round and even stalk, which by
+  cutting transversly, when dry, I manifestly found to be a stiff, hard,
+  and hollow Cane, or Reed, without any kind of knot, or stop, from its
+  bottom, where the leaves encompass'd it, to the top, on which there grows
+  a large seed case, A, cover'd with a thin, and more whitish skin, B,
+  terminated in a long thorny top, which at first covers all the Case, and
+  by degrees, as that swells, the skin cleaves, and at length falls off,
+  with its thorny top and all (which is a part of it) and leaves the seed
+  Case to ripen, and by degrees, to shatter out its seed at a place
+  underneath this cap, B, which before the seed is ripe, appears like a
+  flat barr'd button, without any hole in the middle; but as it ripens, the
+  button grows bigger, and a hole appears in the middle of it, E, out of
+  which, in all probability, the seed falls: For as it ripens by a
+  provision of Nature, that end of this Case turns downward after the same
+  manner as the ears of Wheat and Barley usually do; and opening several of
+  these dry red Cases, F, I found them to be quite
+  hollow, without anything at all in them; whereas when I cut them asunder
+  with a sharp Pen-knife when green, I found in the middle of this great
+  Case, another smaller round Case, between which two, the
+  <i>interstices</i> were fill'd with multitudes of stringie <i>fibres</i>,
+  which seem'd to suspend the lesser Case in the middle of the other, which
+  (as farr as I was able to discern) seem'd full of exceeding small white
+  seeds, much like the seed-bagg in the knop of a Carnation, after the
+  flowers have been two or three days, or a week, fallen off; but this I
+  could not so perfectly discern, and therefore cannot positively affirm
+  it.</p>
+
+  <p>After the seed was fallen away, I found both the Case, Stalk, and
+  Plant, all grow red and wither, and from other parts of the root
+  continually to spring new branches or slips, which by degrees increased,
+  and grew as bigg as the former, seeded, ripen'd, shatter'd, and
+  wither'd.</p>
+
+  <p>I could not find that it observ'd any particular seasons for these
+  several kinds of growth, but rather found it to be springing, mature,
+  ripe, seedy, and wither'd at all times of the year; But I found it most
+  to flourish and increase in warm and moist weather.</p>
+
+  <p>It gathers its nourishments, for the most part, out of some
+  <i>Lapidescent</i>, or other substance corrupted or chang'd from its
+  former texture, or substantial form; for I have found it to grow on the
+  rotten parts of Stone, of Bricks, of Wood, of Bones, of Leather,
+  <i>&amp;c.</i></p>
+
+  <p>It oft grows on the barks of several Trees, spreading it self,
+  sometimes from the ground upwards, and sometimes from some chink or cleft
+  of the bark of the Tree, which has some <i>putrify'd</i> substance in it,
+  but this seems of a distinct kind from that which I observ'd to grow on
+  <i>putrify'd</i> inanimate bodies, and rotten earth.</p>
+
+  <p>There are also great varieties of other kinds of Mosses, which grow on
+  Trees, and several other Plants, of which I shall here make no mention,
+  nor of the Moss growing on the skull of a dead man, which much resembles
+  that of Trees.</p>
+
+  <p>Whether this Plant does sometimes originally spring or rise out of
+  corruption, without any disseminated seed, I have not yet made trials
+  enough to be very much, either positive or negative; for as it seems very
+  hard to conceive how the seed should be generally dispers'd into all
+  parts where there is a corruption begun, unless we may rationally
+  suppose, that this seed being so exceeding small, and consequently
+  exceeding light, is thereby taken up, and carried to and fro in the Air
+  into every place, and by the falling drops of rain is wash'd down out of
+  it, and so dispers'd into all places, and there onely takes root and
+  propagates, where it finds a convenient soil or matrix for it to thrive
+  in; so if we will have it to proceed from corruption, it is not less
+  difficult to conceive,</p>
+
+  <p>First, how the corruption of any Vegetable, much less of any Stone or
+  Brick, should be the Parent of so curiously figur'd, and so perfect a
+  Plant as this is. But here indeed, I cannot but add, that it seems rather
+  to be a product of the Rain in those bodies where it is stay'd, then of
+  the very bodies themselves, since I have found it growing on Marble, and
+  Flint, but always the <i>Microscope</i>, if not the naked eye, would
+  discover some little hole of Dirt in which it was rooted.</p>
+
+  <p>Next, how the corruption of each of those exceedingly differing bodies
+  should all conspire to the production of the same Plant, that is, that
+  Stones, Bricks, Wood, or vegetable substances, and Bones, Leather, Horns,
+  or animate substances, unless we may with some plausibleness say, that
+  Air and Water are the coadjutors, or <i>menstruums</i>, all kinds of
+  <i>putrifactions</i>, and that thereby the bodies (though whil'st they
+  retain'd their substantial forms, were of exceeding differing natures,
+  yet) since they are dissolv'd and mixt into another, they may be very
+  <i>Homogeneous</i>, they being almost resolv'd again into Air, Water, and
+  Earth; retaining, perhaps, one part of their vegetative faculty yet
+  entire, which meeting with congruous assistants, such as the heat of the
+  Air, and the fluidity of the Water, and such like coadjutors and
+  conveniences, acquires a certain vegetation for a time, wholly differing
+  perhaps from that kind of vegetation it had before.</p>
+
+  <p>To explain my meaning a little better by a gross Similitude:</p>
+
+  <p>Suppose a curious piece of Clock-work, that had had several motions
+  and contrivances in it, which, when in order, would all have mov'd in
+  their design'd methods and Periods. We will further suppose, by some
+  means, that this Clock comes to be broken, brused, or otherwise
+  disordered, so that several parts of it being dislocated, are impeded,
+  and so stand still, and not onely hinder its own progressive motion, and
+  produce not the effect which they were design'd for, but because the
+  other parts also have a dependence upon them, put a stop to their motion
+  likewise; and so the whole Instrument becomes unserviceable,, and not fit
+  for any use. This Instrument afterwards, by some shaking and tumbling,
+  and throwing up and down, comes to have several of its parts shaken out,
+  and several of its curious motions, and contrivances, and particles all
+  fallen asunder; here a Pin falls out, and there a Pillar, and here a
+  Wheel, and there a Hammer, and a Spring, and the like, and among the
+  rest, away falls those parts also which were brused and disorder'd, and
+  had all this while impeded the motion of all the rest; hereupon several
+  of those other motions that yet remain, whole springs were not quite run
+  down, being now at liberty, begin each of them to move, thus or thus, but
+  quite after another method then before, there being many regulating parts
+  and the like, fallen away and lost. Upon this, the Owner, who chances to
+  hear and observe some of these effects, being ignorant of the
+  Watch-makers Art, wonders what is betid his Clock, and presently imagines
+  that some Artist has been at work, and has set his Clock in order, and
+  made a new kind of Instrument of it, but upon examining circumstances, he
+  finds there was no such matter, but that the casual slipping out of a Pin
+  had made several parts of his Clock fall to pieces, and that thereby the
+  obstacle that all this while hindred his Clock, together with other
+  usefull parts were fallen out, and so his Clock was set at liberty. And
+  upon winding up those springs again when run down, he finds his Clock to
+  go, but quite after another manner then it was wont heretofore.</p>
+
+  <p>And thus may it be perhaps in the business of Moss, and Mould, and
+  Mushroms, and several other spontaneous kinds of vegetations, which
+  may be caus'd by a vegetative principle,
+  which was a coadjutor to the life and growth of the greater Vegetable,
+  and was by the destroying of the life of it stopt and impeded in
+  performing its office; but afterwards, upon a further corruption of
+  several parts that had all the while impeded it, the heat of the Sun
+  winding up, as it were, the spring, sets it again into a vegetative
+  motion, and this being single, and not at all regulated as it was before
+  (when a part of that greater <i>machine</i> the pristine vegetable) is
+  mov'd after quite a differing manner, and produces effects very differing
+  from those it did before.</p>
+
+  <p>But this I propound onely as a conjecture, not that I am more enclin'd
+  to this <i>Hypothesis</i> then the seminal, which upon good reason I
+  ghess to be Mechanical also, as I may elsewhere more fully shew: But
+  because I may, by this, hint a possible way how this appearance may be
+  solv'd; supposing we should be driven to confess from certain Experiments
+  and Observations made, that such or such Vegetables were produc'd out of
+  the corruption of another, without any concurrent seminal principle (as I
+  have given some reason to suppose, in the description of a
+  <i>Microscopical</i> Mushrome) without derogating at all from the
+  infinite wisdom of the Creator. For this accidental production, as I may
+  call it, does manifest as much, if not very much more, of the excellency
+  of his contrivance as any thing in the more perfect vegetative bodies of
+  the world, even as the accidental motion of the <i>Automaton</i> does
+  make the owner see, that there was much more contrivance in it then at
+  first he imagin'd. But of this I have added more in the description of
+  Mould, and the Vegetables on Rose leaves, <i>&amp;c.</i> those being much
+  more likely to have their original from such a cause then this which I
+<span class="sidenote">
+<a href="images/scheme-13.png" target="_blank"><i>Schem.</i> 13.</a>.
+</span>
+  have here described, in the 13. <i>Scheme</i>, which indeed I cannot
+  conceive otherwise of, then as of a most perfect Vegetable, wanting
+  nothing of the perfections of the most conspicuous and vastest Vegetables
+  of the world, and to be of a rank so high, as that it may very properly
+  be reckon'd with the tall Cedar of <i>Lebanon</i>, as that Kingly
+  Botanist has done.</p>
+
+  <p>We know there may be as much curiosity of contrivance, and excellency
+  of form in a very small Pocket-clock, that takes not up an Inch square of
+  room, as there may be in a Church-clock that fills a whole room; And I
+  know not whether all the contrivances and <i>Mechanisms</i> requisite to
+  a perfect Vegetable, may not be crowded into an exceedingly less room
+  then this of Moss, as I have heard of a striking Watch so small, that it
+  serv'd for a Pendant in a Ladies ear; and I have already given you the
+  description of a Plant growing on Rose leaves, that is abundantly smaller
+  then Moss; insomuch, that neer 1000. of them would hardly make the
+  bigness of one single Plant of Moss. And by comparing the bulk of Moss,
+  with the bulk of the biggest kind of Vegetable we meet with in Story (of
+  which kind we find in some hotter climates, as <i>Guine</i>, and
+  <i>Brasile</i>, the stock or body of some Trees to be twenty foot in
+  Diameter, whereas the body or stem of Moss, for the most part, is not
+  above one sixtieth part of an Inch) we shall find that the bulk of the
+  one will exceed the bulk of the other, no less then 2985984 Millions,
+  or 2985984000000, and supposing the
+  production on a Rose leaf to be a Plant, we shall have of those
+  <i>Indian</i> Plants to exceed a production of the same Vegetable kingdom
+  no less then 1000 times the former number; so prodigiously various are
+  the works of the Creator, and so All-sufficient is he to perform what to
+  man would seem unpossible, they being both alike easie to him, even as
+  one day, and a thousand years are to him as one and the same time.</p>
+
+  <p>I have taken notice of such an infinite variety of those smaller kinds
+  of vegetations, that should I have described every one of them, they
+  would almost have fill'd a Volume, and prov'd bigg enough to have made a
+  new Herbal, such multitudes are there to be found in moist hot weather,
+  especially in the Summer time, on all kind of putrifying substances,
+  which, whether they do more properly belong to the <i>Classis</i> of
+  <i>Mushrooms</i>, or <i>Moulds</i>, or <i>Mosses</i>, I shall not now
+  dispute, there being some that seem more properly of one kind, others of
+  another, their colours and magnitudes being as much differing as their
+  Figures and substances.</p>
+
+  <p>Nay, I have observ'd, that putting fair Water (whether Rain-water or
+  Pump-water, or <i>May-dew</i> or Snow-water, it was almost all one) I
+  have often observ'd, I say, that this Water would, with a little
+  standing, tarnish and cover all about the sides of the Glass that lay
+  under water, with a lovely green; but though I have often endeavour'd to
+  discover with my <i>Microscope</i> whether this green were like Moss, or
+  long striped Sea-weed, or any other peculiar form, yet so ill and
+  imperfect are our <i>Microscopes</i>, that I could not certainly
+  discriminate any.</p>
+
+  <p>Growing Trees also, and any kinds of Woods, Stones, Bones,
+  <i>&amp;c.</i> that have been long expos'd to the Air and Rain, will be
+  all over cover'd with a greenish scurff, which will very much foul and
+  green any kind of cloaths that are rubb'd against it; viewing this, I
+  could not certainly perceive in many parts of it any determinate form,
+  though in many I could perceive a Bed as 'twere of young Moss, but in
+  other parts it look'd almost like green bushes, and very confus'd, but
+  always of what ever irregular Figures the parts appear'd of, they were
+  always green, and seem'd to be either some Vegetable, or to have some
+  vegetating principle.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXII" id="obsXXII">XXII</a>. <i>Of common </i>Sponges<i>, and several other </i>Spongie<i>
+fibrous bodies.</i></h3>
+
+  <p>A Sponge is commonly reckon'd among the <i>Zoophyts</i>, or Plant
+  Animals; and the <i>texture</i> of it, which the <i>Microscope</i>
+  discovers, seems to confirm it; for it is of a form whereof I never
+  observ'd any other Vegetable, and indeed, it seems impossible that any
+  should be of it, for it consists of an infinite number of small short
+  <i>fibres</i>, or nervous parts, much of the same bigness, curiously
+  jointed or contex'd together in the form of a Net, as is more plainly
+  manifest by the little Draught which I have added, in
+  the third <i>Figure</i> of the IX. <i>Scheme</i>, of a piece of it, which
+<span class="sidenote">
+<a href="images/scheme-09.png" target="_blank"><i>Schem.</i> 9.</a><br /><i>Fig.</i> 3.
+</span>
+  you may perceive represents a confus'd heap of the fibrous parts
+  curiously jointed and implicated. The joints are, for the most part,
+  where three <i>fibres</i> onely meet, for I have very seldom met with any
+  that had four.</p>
+
+  <p>At these joints there is no one of the three that seems to be the
+  stock whereon the other grow, but each of the <i>fibres</i> are, for the
+  most part, of an equal bigness, and seem each of them to have an equal
+  share in the joint; the <i>fibres</i> are all of them much about the same
+  bigness, not smaller towards the top of the Sponge, and bigger neerer the
+  bottom or root, as is usuall in Plants, the length of each between the
+  joints, is very irregular and different; the distance between some two
+  joints, being ten or twelve times more then between some others.</p>
+
+  <p>Nor are the joints regular, and of an <i>equitriagonal Figure</i>,
+  but, for the most part, the three <i>fibres</i> so meet, that they
+  compose three angles very differing all of them from one another.</p>
+
+  <p>The meshes likewise, and holes of this reticulated body, are not less
+  various and irregular: some <i>bilateral</i>, others <i>trilateral</i>,
+  and <i>quadrilateral</i> Figures; nay, I have observ'd some meshes to
+  have 5, 6, 7, 8, or 9. sides, and some to have onely one, so exceeding
+  various is the <i>Lusus Naturæ</i> in this body.</p>
+
+  <p>As to the outward appearance of this Vegetative body, they are so
+  usuall everywhere, that I need not describe them, consisting of a soft
+  and porous substance, representing a Lock, sometimes a fleece of Wooll;
+  but it has besides these small <i>microscopical</i> pores which lie
+  between the <i>fibres</i>, a multitude of round pores or holes, which,
+  from the top of it, pierce into the body, and sometimes go quite through
+  to the bottom.</p>
+
+  <p>I have observ'd many of these Sponges, to have included likewise in
+  the midst of their fibrous contextures, pretty large friable stones,
+  which must either have been inclos'd whil'st this Vegetable was in
+  formation, or generated in those places after it was perfectly shap'd.
+  The later of which seems the more improbable, because I did not find that
+  any of these stony substances were perforated with the <i>fibres</i> of
+  the Sponge.</p>
+
+  <p>I have never seen nor been enform'd of the true manner of the growing
+  of Sponges on the Rock; whether they are found to increase from little to
+  great, like Vegetables, that is, part after part, or like Animals, all
+  parts equally growing together; or whether they be <i>matrices</i> or
+  feed-baggs of any kind of Fishes, or some kind of watry Insect; or
+  whether they are at any times more soft and tender, or of another nature
+  and texture, which things, if I knew how, I should much desire to be
+  informed of: but from a cursory view that I at first made with my
+  <i>Microscope</i>, and some other trials, I supposed it to be some Animal
+  substance cast out, and fastned upon the Rocks in the form of a froth, or
+  <i>congeries</i> of bubbles, like that which I have often observ'd on
+  Rosemary, and other Plants (wherein is included a little Insect) that all
+  the little films which divide these bubbles one from another, did
+  presently, almost after the substance began to grow a little harder,
+  break, and leave onely the thread behind, which might be, as 'twere, the
+  angle or thread between the bubbles, that the great
+  holes or pores observable in these Sponges were made by the eruption of
+  the included <i>Heterogeneous</i> substance (whether air, or some other
+  body, for many other fluid bodies will do the same thing) which breaking
+  out of the lesser, were collected into very large bubbles, and so might
+  make their way out of the Sponge, and in their passage might leave a
+  round cavity; and if it were large, might carry up with it the adjacent
+  bubbles, which may be perceiv'd at the outside of the Sponge, if it be
+  first throughly wetted, and sufferr'd to plump itself into its natural
+  form, or be then wrung dry, and suffer'd to expand it self again, which
+  it will freely do whil'st moist: for when it has thus plump'd it self
+  into its natural shape and dimensions, 'tis obvious enough that the
+  mouths of the larger holes have a kind of lip or rising round about them,
+  but the other smaller pores have little or none. It may further be found,
+  that each of these great pores has many other small pores below, that are
+  united unto it, and help to constitute it, almost like so many rivulets
+  or small streams that contribute to the maintenance of a large River. Nor
+  from this <i>Hypothesis</i> would it have been difficult to explicate,
+  how those little branches of <i>Coral</i>, smal <i>Stones</i>,
+  <i>shells</i>, and the like, come to be included by these frothy bodies:
+  But this inded was but a conjecture; and upon a more accurate enquiry
+  into the form of it with the <i>Microscope</i>, it seems not to be the
+  true origine of them; for whereas Sponges have onely three arms which
+  join together at each knot, if they had been generated from bubbles they
+  must have had four.</p>
+
+  <p>But that they are Animal Substances, the <i>Chymical</i> examination
+  of them seems to manifest, they affording a volatil Salt and spirit, like
+  <i>Harts-Horn</i>, as does also their great strength and toughness, and
+  their smell when burn'd in the Fire or a Candle, which has a kind of
+  fleshy sent, not much unlike to hair. And having since examin'd several
+  Authors concerning them, among others; I find this account given by
+  <i>Bellonius</i>, in the XI. <i>Chap.</i> of his 2<sup>d</sup> Book,
+  <i>De Aquatilibus</i>. <i>Spongiæ recentes</i>, says he, <i>à siccis
+  longe diversæ, scopulis aquæ marinæ ad duos vel tres cubitos, nonnunquam
+  quatuor tantum digitos immersis, ut fungi arboribus adhærent, sordido
+  quodam succo aut mucosa potius sanie refertæ, usque adeò f&#339;tida, ut
+  vel eminus nauseam excitet, continetur autem iis cavernis, quas inanes in
+  siccis &amp; lotis Spongiis cernimus: Putris pulmonis modo nigræ
+  conspiciuntur, verùm quæ in sublimi aquæ nascuntur multo magis opaca
+  nigredine suffusæ sunt. Vivere quidem Spongias adhærendo
+  </i>Aristoteles<i> censet: absolute vero minime: sensumque aliquem
+  habere, vel eo argumento (inquit) credantur, quod difficillime
+  abstrahantur, nisi clanculum agatur: Atq; ad avulsoris accessum ita
+  contrahantur, ut eas evellere difficile sit, quod idem etiam faciunt
+  quoties flatus tempestatésque urgent. Puto autem illis succum sordidum
+  quem supra diximus carnis loco à natura attributum fuisse: atque meatibus
+  latioribus tanquam intestinis aut interaneis uti. Cæterum pars ea quæ
+  Spongiæ cautibus adhærent est tanquam folii petiolus, à quo veluti collum
+  quoddam gracile incipit: quod deinde in latitudinem diffusum capitis
+  globum facit. Recentibus nihil est fistulosum, hæsitantque tanquam
+  radicibus. Superne omnes propemodum meatus concreti latent: inferne verò
+  quaterni aut quini patent, per quos eas
+  sugere existimamus</i>. From which Description, they seem to be a kind of
+  Plant-Animal that adheres to a Rock, and these small <i>fibres</i> or
+  threads which we have described, seem to have been the Vessels which
+  ('tis very probable) were very much bigger whil'st the <i>Interstitia</i>
+  were fill'd (as he affirms) with a mucous, pulpy or fleshy substance; but
+  upon the drying were shrunk into the bigness they now appear.</p>
+
+  <p>The texture of it is such, that I have not yet met with any other body
+  in the world that has the like, but onely one of a larger sort of Sponge
+  (which is preserv'd in the <i>Museum Harveanum</i> belonging to the most
+  Illustrious and most learned Society of the <i>Physicians</i> of
+  <i>London</i>) which is of a horney, or rather of a <i>petrify'd</i>
+  substance. And of this indeed, the texture and make is exactly the same
+  with common Sponges, but onely that both the holes and the <i>fibres</i>,
+  or texture of it is exceedingly much bigger, for some of the holes were
+  above an Inch and half over, and the <i>fibres</i> and <i>texture</i> of
+  it was bigg enough to be distinguished easily with ones eye, but
+  conspicuously with an ordinary single <i>Microscope</i>. And these
+  indeed, seem'd to have been the habitation of some Animal; and examining
+  <i>Aristotle</i>, I find a very consonant account hereunto, namely, that
+  he had known a certain little Animal, call'd <i>Pinnothera</i>, like a
+  Spider, to be bred in those caverns of a Sponge, from within which, by
+  opening and closing those holes, he insnares and catches the little
+  Fishes; and in another place he says, That 'tis very confidently
+  reported, that there are certain Moths or Worms that reside in the
+  cavities of a Sponge, and are there nourished: Notwithstanding all which
+  Histories, I think it well worth the enquiring into the History and
+  nature of a Sponge, it seeming to promise some information of the Vessels
+  in Animal substances, which (by reason of the solidity of the interserted
+  flesh that is not easily remov'd, without destroying also those
+  interspers'd Vessels) are hitherto undiscover'd; whereas here in a
+  Sponge, the <i>Parenchyma</i>, it seems, is but a kind of mucous gelly,
+  which is very easily and cleerly wash'd away.</p>
+
+  <p>The reason that makes me imagine, that there may probably be some such
+  texture in Animal substances, is, that examining the texture of the
+  filaments of tann'd Leather, I find it to be much of the same nature and
+  strength of a Sponge; and with my <i>Microscope</i>, I have observ'd many
+  such joints and knobs, as I have described in Sponges, the <i>fibres</i>
+  also in the hollow of several sorts of Bones, after the Marrow has been
+  remov'd, I have found somewhat to resemble this texture, though, I
+  confess, I never yet found any texture exactly the same, nor any for
+  curiosity comparable to it.</p>
+
+  <p>The filaments of it are much smaller then those of Silk, and through
+  the <i>Microscope</i> appear very neer as transparent, nay, some parts of
+  them I have observ'd much more.</p>
+
+  <p>Having examin'd also several kinds of Mushroms, I finde their texture
+  to be somewhat of this kind, that is, to consist of an infinite company
+  of small filaments, every way contex'd and woven together, so as to make
+  a kind of cloth, and more particularly, examining a piece of Touch-wood
+  (which is a kind <i>Jews-ear</i>, or Mushrom, growing here in
+  <i>England</i> also, on several sorts of Trees,
+  such as Elders, Maples, Willows, <i>&amp;c.</i> and is commonly call'd by
+  the name of <i>Spunk</i>; but that we meet with to be sold in Shops, is
+  brought from beyond Seas) I found it to be made of an exceeding delicate
+  texture: For the substance of it feels, and looks to the naked eye, and
+  may be stretch'd any way, exactly like a very fine piece of
+  <i>Chamois</i> Leather, or wash'd Leather, but it is of somewhat a
+  browner hew, and nothing neer so strong; but examining it with my
+  <i>Microscope</i>, I found it of somewhat another make then any kind of
+  Leather; for whereas both <i>Chamois</i>, and all other kinds of Leather
+  I have yet view'd, consist of an infinite company of filaments, somewhat
+  like bushes interwoven one within another, that is, of bigger parts or
+  stems, as it were, and smaller branchings that grow out of them; or like
+  a heap of Ropes ends, where each of the larger Ropes by degrees seem to
+  split or untwist, into many smaller Cords, and each of those Cords into
+  smaller Lines, and those Lines into Threads, <i>&amp;c.</i> and these
+  strangely intangled, or interwoven one within another: The texture of
+  this Touch-wood seems more like that of a Lock or a Fleece of Wool, for
+  it consists of an infinite number of small filaments, all of them, as
+  farr as I could perceive, of the same bigness like those of a Sponge, but
+  that the <i>filaments</i> of this were not a twentieth part of the
+  bigness of those of a Sponge; and I could not so plainly perceive their
+  joints, or their manner of interweaving, though, as farr as I was able to
+  discern with that <i>Microscope</i> I had, I suppose it to have some kind
+  of resemblance, but the joints are nothing neer so thick, nor without
+  much trouble visible.</p>
+
+  <p>The filaments I could plainly enough perceive to be even, round,
+  cylindrical, transparent bodies, and to cross each other every way, that
+  is, there were not more seem'd to lie <i>horizontally</i> then
+  <i>perpendicularly</i> and thwartway, so that it is somewhat difficult
+  to conceive how they should grow in that manner. By tearing off a small
+  piece of it, and looking on the ragged edge, I could among several of
+  those <i>fibres</i> perceive small joints, that is, one of those hairs
+  split into two, each of the same bigness with the other out of which they
+  seem'd to grow, but having not lately had an opportunity of examining
+  their manner of growth, I cannot positively affirm any thing of them.</p>
+
+  <p>But to proceed, The swelling of Sponges upon wetting, and the rising
+  of the Water in it above the surface of the Water that it touches, are
+  both from the same cause, of which an account is already given in the
+  sixth Observation.</p>
+
+  <p>The substance of them indeed, has so many excellent properties, scarce
+  to be met with in any other body in the world, that I have often wondered
+  that so little use is made of it, and those onely vile and sordid;
+  certainly, if it were well consider'd, it would afford much greater
+  conveniencies.</p>
+
+  <p>That use which the Divers are said to make of it, seems, if true, very
+  strange, but having made trial of it my self, by dipping a small piece of
+  it in very good Sallet-oyl, and putting it in my mouth, and then keeping
+  my mouth and nose under water, I could not find any such thing; for I
+  was as soon out of breath as if I had had
+  no Sponge, nor could I fetch my breath without taking in water at my
+  mouth; but I am very apt to think, that were there a contrivance whereby
+  the expir'd air might be forc'd to pass through a wet or oyly Sponge
+  before it were again inspir'd, it might much cleanse, and strain away
+  from the Air divers fuliginous and other noisome steams, and the dipping
+  of it in certain liquors might, perhaps, so renew that property in the
+  Air which it loses in the Lungs, by being breath'd, that one square foot
+  of Air might last a man for respiration much longer, perhaps, then ten
+  will now serve him of common Air.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXIII" id="obsXXIII">XXIII</a>. <i>Of the curious texture of </i>Sea-weeds<i>.</i></h3>
+
+  <p>For curiosity and beauty, I have not among all the Plants or
+  Vegetables I have yet observ'd, seen any one comparable to this Sea-weed
+  I have here describ'd, of which I am able to say very little more then
+<span class="sidenote">
+<a href="images/scheme-09.png" target="_blank"><i>Schem.</i> 9.</a><br /><i>Fig.</i> 2.
+</span>
+  what is represented by the second <i>Figure</i> of the ninth
+  <i>Scheme</i>: Namely, that it is a Plant which grows upon the Rocks
+  under the water, and increases and spreads it self into a great tuft,
+  which is not onely handsomely branch'd into several leaves, but the whole
+  surface of the Plant is cover'd over with a most curious kind of carv'd
+  work, which consists of a texture much resembling a Honey-comb; for the
+  whole surface on both sides is cover'd over with a multitude of very
+  small holes, being no bigger then so many holes made with the point of a
+  small Pinn, and rang'd in the neatest and most delicate order imaginable,
+  they being plac'd in the manner of a <i>Quincunx</i>, or very much like
+  the rows of the eyes of a Fly, the rows or orders being very regular,
+  which way soever they are observ'd: what the texture was, as it appear'd
+  through a pretty bigg Magnifying <i>Microscope</i>, I have here adjoin'd
+<span class="sidenote">
+<a href="images/scheme-14.png" target="_blank"><i>Schem.</i> 14.</a><br /><i>Fig.</i> 1.
+</span>
+  in the first <i>Figure</i> of the 14. <i>Scheme.</i> which round Area
+  ABCD represents a part of the surface about one eighth part of an Inch in
+  Diameter: Those little holes, which to the eye look'd round, like so many
+  little spots, here appear'd very regularly shap'd holes, representing
+  almost the shape of the sole of a round toed shoe, the hinder part of
+  which, is, as it were, trod on or cover'd by the toe of that next below
+  it; these holes seem'd wall'd about with a very thin and transparent
+  substance, looking of a pale straw-colour; from the edge of which,
+  against the middle of each hole, were sprouted out four small transparent
+  straw-colour'd Thorns, which seem'd to protect and cover those cavities,
+  from either side two; neer the root of this Plant, were sprouted out
+  several small branches of a kind of bastard <i>Coralline</i>, curiously
+  branch'd, though small.</p>
+
+  <p>And to confirm this, having lately the opportunity of viewing the
+  large Plant (if I may so call it) of a Sponge <i>petrify'd</i>, of which
+  I made mention in the last Observation, I found, that each of the
+  Branches or Figures of it, did, by the range of its pores, exhibit just
+  such a texture, the rows of pores crossing one another,
+  much after the manner as the rows of eyes do which are describ'd in the
+  26. <i>Scheme</i>: <i>Coralline</i> also, and several sorts of white
+  <i>Coral</i>, I have with a <i>Microscope</i> observ'd very curiously
+  shap'd. And I doubt not, but that he that shall observe these several
+  kinds of Plants that grow upon Rocks, which the Sea sometimes overflows,
+  and those heaps of others which are vomited out of it upon the shore, may
+  find multitudes of little Plants, and other bodies, which like this will
+  afford very beautifull objects for the <i>Microscope</i>; and this
+  <i>Specimen</i> here is adjoin'd onely to excite their curiosities who
+  have opportunity of observing to examine and collect what they find
+  worthy their notice; for the Sea, among terrestrial bodies, is also a
+  <i>prolifick</i> mother, and affords as many Instances of
+  <i>spontaneous</i> generations as either the Air or Earth.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXIV" id="obsXXIV">XXIV</a>. <i>Of the surfaces of </i>Rosemary<i>, and other leaves.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-14.png" target="_blank"><i>Schem.</i> 14.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>This which is delineated within the circle of the second <i>Figure</i>
+  of the 14. <i>Scheme</i>, is a small part of the back or under side of a
+  leaf of Rosemary, which I did not therefore make choice of because it had
+  any thing peculiar which was not observable with a <i>Microscope</i> in
+  several other Plants, but because it exhibits at one view,</p>
+
+  <p>First, a smooth and shining surface, namely, AB, which is a part of
+  the upper side of the leaf, that by a kind of hem or doubling of the leaf
+  appears on this side. There are multitudes of leaves, which surfaces are
+  like this smooth, and as it were quilted, which look like a curious
+  quilted bagg of green Silk, or like a Bladder, or some such pliable
+  transparent substance, full stuffed out with a green juice or liquor; the
+  surface of Rue, or Herbgrass, is polish'd, and all over indented, or
+  pitted, like the Silk-worm's Egg, which I shall anon describe; the smooth
+  surfaces of other Plants are otherwise quilted, Nature in this, as it
+  were, expressing her Needle-work, or imbroidery.</p>
+
+  <p>Next a downy or bushy surface, such as is all the under side almost,
+  appearing through the <i>Microscope</i> much like a thicket of bushes,
+  and with this kind of Down or Hair the leaves and stalks of multitudes of
+  Vegetables are covered; and there seems to be as great a variety in the
+  shape, bulk, and manner of the growing of these secundary Plants, as I
+  may call them (they being, as it were, a Plant growing out of a Plant, or
+  somewhat like the hairs of Animals) as there is to be found amongst small
+  shrubs that compose bushes; but for the most part, they consist of small
+  transparent parts, some of which grow in the shape of small Needles or
+  Bodkins, as on the Thistle, Cowag-ecod and Nettle; others in the form of
+  Cat's claws, as in Cliders, the beards of Barley, the edges of several
+  sorts of Grass and Reeds, <i>&amp;c.</i> in other, as Coltsfoot,
+  Rose-campion, Aps, Poplar, Willow, and almost all other downy Plants,
+  they grow in the form of bushes very much diversify'd in each particular
+  Plant, That which I have before in the 19.
+  Observation noted on Rose-leaves, is of a quite differing kind, and seems
+  indeed a real Vegetable, distinct from the leaf.</p>
+
+  <p>Thirdly, among these small bushes are observable an infinite company
+  of small round Balls, exactly Globular, and very much resembling Pearls,
+  namely, CCCC, of these there maybe multitudes observ'd in Sage, and
+  several other Plants, which I suppose was the reason why <i>Athanasius
+  Kircher</i> supposed them to be all cover'd with Spiders Eggs, or young
+  Spiders, which indeed is nothing else but some kind of gummous
+  exsudation, which is always much of the same bigness. At first sight of
+  these, I confess, I imagin'd that they might have been some kind of
+  <i>matrices</i>, or nourishing receptacles for some small Insect, just as
+  I have found Oak-apples, and multitudes of such other large excrescencies
+  on the leaves and other parts of Trees and shrubs to be for Flyes, and
+  divers other Insects, but observing them to be there all the year, and
+  scarce at all to change their magnitude, that conjecture seem'd not so
+  probable. But what ever be the use of it, it affords a very pleasant
+  object through the <i>Microscope</i>, and may, perhaps, upon further
+  examination, prove very luciferous.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXV" id="obsXXV">XXV</a>. <i>Of the stinging points and juice of </i>Nettles<i>, and
+some other venomous Plants.</i></h3>
+
+  <p>A Nettle is a Plant so well known to every one, as to what the
+  appearance of it is to the naked eye, that it needs no description; and
+  there are very few that have not felt as well as seen it; and therefore
+  it will be no news to tell that a gentle and slight touch of the skin by
+  a Nettle, does oftentime, not onely create very sensible and acute pain,
+  much like that of a burn or scald, but often also very angry and hard
+  swellings and inflamations of the parts, such as will presently rise, and
+  continue swoln divers hours. These observations, I say, are common
+  enough; but how the pain is so suddenly created, and by what means
+  continued, augmented for a time, and afterwards diminish'd, and at length
+  quite exstinguish'd, has not, that I know, been explain'd by any.</p>
+
+  <p>And here we must have recourse to our <i>Microscope</i>, and that
+  will, if almost any part of the Plant be looked on, shew us the whole
+  surface of it very thick set with turn-Pikes, or sharp Needles, of the
+<span class="sidenote">
+<a href="images/scheme-15.png" target="_blank"><i>Schem.</i> 15.</a><br /><i>Fig.</i> 1.
+</span>
+  shape of those represented in the 15. <i>Scheme</i> and first
+  <i>Figure</i> by AB, which are visible also to the naked eye; each of
+  which consists of two parts very distinct for shape, and differing also
+  in quality from one another. For the part A, is shaped very much like a
+  round Bodkin, from B tapering till it end in a very sharp point; it is of
+  substance very hard and stiff, exceedingly transparent and cleer, and, as
+  I by many trials certainly found, is hollow from top to bottom.</p>
+
+  <p>This I found by this Experiment, I had a very convenient
+  <i>Microscope</i> with a single Glass which
+  drew about half an Inch, this I had fastned into a little frame, almost
+  like a pair of Spectacles, which I placed before mine eyes, and so
+  holding the leaf of a Nettle at a convenient distance from my eye, I did
+  first, with the thrusting of several of these bristles into my skin,
+  perceive that presently after I had thrust them in I felt the burning
+  pain begin; next I observ'd in divers of them, that upon thrusting my
+  finger against their tops, the Bodkin (if I may so call it) did not in
+  the least bend, but I could perceive moving up and down within it a
+  certain liquor, which upon thrusting the Bodkin against its basis, or
+  bagg B, I could perceive to rise towards the top, and upon taking away my
+  hand, I could see it again subside, and shrink into the bagg; this I did
+  very often, and saw this <i>Phænomenon</i> as plain as I could ever see a
+  parcel of water ascend and descend in a pipe of Glass. But the basis
+  underneath these Bodkins on which they were fast, were made of a more
+  pliable substance, and looked almost like a little bagg of green Leather,
+  or rather resembled the shape and surface of a wilde Cucumber, or
+  <i>cucumeris asinini</i>, and I could plainly perceive them to be certain
+  little baggs, bladders, or receptacles full of water, or as I ghess, the
+  liquor of the Plant, which was poisonous, and those small Bodkins were
+  but the Syringe-pipes, or Glyster-pipes, which first made way into the
+  skin, and then served to convey that poisonous juice, upon the pressing
+  of those little baggs, into the interior and sensible parts of the skin,
+  which being so discharg'd, does corrode, or, as it were, burn that part
+  of the skin it touches; and this pain will sometimes last very long,
+  according as the impression is made deeper or stronger.</p>
+
+  <p>The other parts of the leaf or surface of the Nettle, have very little
+  considerable, but what is common to most of these kinds of Plants, as the
+  ruggedness or indenting, and hairiness, and other roughnesses of the
+  surface or out-side of the Plant, of which I may say more in another
+  place. As I shall likewise of certain little pretty cleer Balls or Apples
+  which I have observed to stick to the sides of these leaves, both on the
+  upper and under side, very much like the small Apples which I have often
+  observ'd to grow on the leaves of an Oak call'd <i>Oak-apples</i> which
+  are nothing but the <i>Matrices</i> of an Infect, as I elsewhere
+  shew.</p>
+
+  <p>The chief thing therefore is, how this Plant comes, by so slight a
+  touch, to create so great a pain; and the reason of this seems to be
+  nothing else, but the corrosive penetrant liquor contain'd in the small
+  baggs or bladders, upon which grow out those sharp Syringe-pipes, as I
+  before noted; and very consonant to this, is the reason of the pain
+  created by the sting of a Bee, Wasp, <i>&amp;c.</i> as I elsewhere shew:
+  For by the Dart, which is likewise a pipe, is made a deep passage into
+  the skin, and then by the anger of the Fly, is his gally poisonous liquor
+  injected; which being admitted among the sensible parts, and so mix'd
+  with the humours or <i>stagnating</i> juices of that part, does create an
+  Ebullition perhaps, or <i>effervescens</i>, as is usually observ'd in the
+  mingling of two differing <i>Chymical saline</i> liquors, by which means
+  the parts become swell'd, hard, and very painfull; for thereby the
+  nervous and sensible parts are not onely stretch'd and strain'd
+  beyond their natural <i>tone</i>, but are
+  also prick'd, perhaps, or corroded by the pungent and incongruous parts
+  of the intruded liquor.</p>
+
+  <p>And this seems to be the reason, why <i>Aqua fortis</i>, and other
+  <i>saline</i> liquors, if they come to touch the sensitive parts, as in a
+  cut of the skin, or the like, do so violently and intollerably
+  <i>excruciate</i> and torment the Patient. And 'tis not unlikely, but the
+  Inventors of that Diabolical practice of poisoning the points of Arrows
+  and Ponyards, might receive their first hint from some such Instance in
+  natural contrivances, as this of the Nettle: for the ground why such
+  poison'd weapons kill so infallibly as they do, seems no other then this
+  of our Nettle's stinging; for the Ponyard or Dart makes a passage or
+  entrance into the sensitive or vital parts of the body, whereby the
+  contagious substance comes to be dissolv'd by, and mix'd with the fluid
+  parts or humours of the body, and by that means spreads it self by
+  degrees into the whole liquid part of the body, in the same manner, as a
+  few grains of Salt, put into a great quantity of Water, will by degrees
+  diffuse it self over the whole.</p>
+
+  <p>And this I take to be the reason of killing of Toads, Frogs, Effs, and
+  several Fishes, by strewing Salt on their backs (which Experiment was
+  shewn to the <i>Royal Society</i> by a very ingenious Gentleman, and a
+  worthy Member of it) for those creatures having always a continual
+  exsudation, as it were, of slimy and watry parts, sweating out of the
+  pores of their skin, the <i>saline</i> particles, by that means obtain a
+  <i>vehicle</i>, which conveys them into the internal and vital parts of
+  the body.</p>
+
+  <p>This seems also to be the reason why bathing in Mineral waters are
+  such soveraign remedies for multitudes of distempers, especially
+  chronical; for the liquid &amp; warm <i>vehicles</i> of the Mineral
+  particles, which are known to be in very considerable quantities in those
+  healing baths, by the body's long stay in them, do by degrees steep and
+  insinuate themselves into the pores and parts of the skin, and thereby
+  those Mineral particles have their ways and passages open'd to penetrate
+  into the inner parts, and mingle themselves with the <i>stagnant</i>
+  juices of the several parts; besides, many of those offensive parts which
+  were united with those <i>stagnant</i> juices, and which were contrary to
+  the natural constitution of the parts, and so become irksome and painfull
+  to the body, but could not be discharged, because Nature had made no
+  provision for such accidental mischiefs, are, by means of this soaking,
+  and filling the pores of the skin with a liquor, afforded a passage
+  through that liquor that fills the pores into the ambient fluid, and
+  thereby the body comes to be discharged.</p>
+
+  <p>So that 'tis very evident, there may be a good as well as an evil
+  application of this Principle. And the ingenious Invention of that
+  Excellent person, Doctor <i>Wren</i> of injecting liquors into the veins
+  of an Animal, seems to be reducible to this head: I cannot stay, nor is
+  this a fit place, to mention the several Experiments made of this kind by
+  the most incomparable Mr. <i>Boyle</i>, the multitudes made by the lately
+  mention'd <i>Physician</i> Doctor <i>Clark</i>, the History whereof, as
+  he has been pleas'd to communicate to the <i>Royal Society</i>, so he may
+  perhaps be prevail'd with to make publique himself: But I shall rather
+  hint, that certainly, if this Principle were well
+  consider'd, there might, besides the further improving of Bathing and
+  Syringing into the veins, be thought on several ways, whereby several
+  obstinate distempers of a humane body, such as the Gout, Dropsie, Stone,
+  <i>&amp;c.</i> might be master'd, and expell'd; and good men might make
+  as good a use of it, as evil men have made a perverse and Diabolical.</p>
+
+  <p>And that the filling of the pores of the skin with some fluid
+  <i>vehicle</i>, is of no small efficacy towards the preparing a passage
+  for several kinds of penetrant juices, and other dissoluble bodies, to
+  insinuate themselves within the skin, and into the sensitive parts of the
+  body, may be, I think, prov'd by an Instance given us by
+  <i>Bellonius</i>, in the 26. <i>Chapter</i> of the second Book of his
+  <i>Observations</i>, which containing a very remarkable Story I have here
+  transcrib'd: <i>Cum Chamæleonis nigri radices</i> (says he) <i>apud Pagum
+  quendam Livadochorio nuncupatum erui curaremus, plurimi Græci &amp; Turcæ
+  spectatum venerunt quid erueremus, eas vero frustulatim secabamus, &amp;
+  filo trajiciebamus ut facilius exsiccari possent. Turcæ in eo negotio
+  occupatos nos videntes, similiter eas radices tractare &amp; secare
+  voluerunt: at cum summus esset æstus, &amp; omnes sudore maderent,
+  quicunque eam radicem manibus tractaverant sudoremque absterserant, aut
+  faciem digitis scalpserant, tantam pruriginem iis locis quos attigerant
+  postea senserunt, ut aduri viderentur. Chamæleonis enim nigri radix ea
+  virtute pollet, ut cuti applicata ipsam adeo inflammet, ut nec squillæ,
+  nec urticæ ullæ centesima parte ita adurent: At prurigo non adeo
+  celeriter sese prodit. Post unam aut alteram porro horam, singuli variis
+  faciei locis cutem adeo inflammatam habere cæpimus ut tota sanguinea
+  videretur, atque quo magis eam confricabamus, tanto magis excitabatur
+  prurigo. Fonti assidebamus sub platano, atque initio pro ludicro
+  habebamus &amp; ridebamus: at tandem illi plurimum indignati sunt, &amp;
+  nisi asseverassemus nunquam expertos tali virtute eam plantam pollere,
+  haud dubie male nos multassent, Attamen nostra excusatio fuit ab illis
+  facilitus accepta, cum eodem incommodo nos affectos conspicerent. Mirum
+  sane quod in tantillo radice tam ingentem efficaciam nostro malo experti
+  sumus.</i></p>
+
+  <p>By which observation of his, it seems manifest, that their being all
+  cover'd with sweat who gather'd and cut this root of the black
+  <i>Chameleon</i> Thistle, was the great reason why they suffer'd that
+  inconvenience, for it seems the like circumstance had not been before
+  that noted, nor do I find any mention of such a property belonging to
+  this Vegetable in any of the Herbals I have at present by me.</p>
+
+  <p>I could give very many Observations which I have made of this kind,
+  whereby I have found that the best way to get a body to be insinuated
+  into the substance or insensible pores of another, is first, to find a
+  fluid <i>vehicle</i> that has some congruity, both to the body to be
+  insinuated, and to the body into whose pores you would have the other
+  convey'd. And in this Principle lies the great mystery of staining
+  several sorts of bodies, as Marble, Woods, Bones, <i>&amp;c.</i> and of
+  Dying Silks, Cloaths, Wools, Feathers, <i>&amp;c.</i> But these being
+  digressions, I shall proceed to:</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXVI" id="obsXXVI">XXVI</a>. <i>Of </i>Cowage<i>, and the itching operation of some bodies.</i></h3>
+
+  <p>There is a certain Down of a Plant, brought from the
+  <i>East-Indies</i>, call'd commonly, though very improperly,
+  <i>Cow-itch</i>, the reason of which mistake
+  is manifest enough from the description of it, which Mr. <i>Parkinson</i>
+  sets down in his <i>Herbal</i>, Tribe XI. Chap. 2. <i>Phasiolus siliqua
+  hirsuta; The hairy Kidney-bean, called in </i>Zurratte<i> where it grows,
+  Couhage: We have had</i> (says he) <i>another of this kind brought us out
+  of the </i>East-Indies<i>, which being planted was in shew like the
+  former, but came not to perfection, the unkindly season not suffering it
+  to shew the flower; but of the Cods that were brought, some were smaller,
+  shorter, and rounder then the Garden kind; others much longer, and many
+  growing together, as it were in clusters, and cover'd all over with a
+  brown short hairiness, so fine, that if any of it be rubb'd, or fall on
+  the back of ones hand, or other tender parts of the skin, it will cause a
+  kind of itching, but not strong, nor long induring, but passing quickly
+  away, without either danger or harm; the Beans were smaller then
+  ordinary, and of a black shining colour.</i></p>
+
+  <p>Having one of these Cods given me by a Sea-Captain, who had frequented
+  those parts, I found it to be a small Cod, about three Inches long, much
+  like a short Cod of <i>French Beans</i>, which had six Beans in it, the
+  whole surface of it was cover'd over with a very thick and shining brown
+  Down or Hair, which was very fine, and for its bigness stiff; taking some
+  of this Down, and rubbing it on the back of my hand, I found very little
+  or no trouble, only I was sensible that several of these little downy
+  parts with rubbing did penetrate, and were sunk, or stuck pretty deep
+  into my skin. After I had thus rubb'd it for a pretty while, I felt very
+  little or no pain, in so much that I doubted, whether it were the true
+  Couhage; but whil'st I was considering; I found the Down begin to make my
+  hand itch, and in some places to smart again, much like the stinging of a
+  Flea or Gnat, and this continued a pretty while, so that by degrees I
+  found my skin to be swell'd with little red pustules, and to look as if
+  it had been itchie. But suffering it without rubbing or scratching, the
+  itching tickling pain quickly grew languid, and within an hour I felt
+  nothing at all, and the little <i>protuberancies</i> were vanish'd.</p>
+
+  <p>The cause of which odd <i>Phænomenon</i>, I suppose to be much the
+  same with that of the stinging of a Nettle, for by the <i>Microscope</i>,
+  I discover'd this Down to consist of a multitude of small and slender
+  conical bodies, much resembling Needles or Bodkins, such as are
+<span class="sidenote">
+<a href="images/scheme-16.png" target="_blank"><i>Schem.</i> 16.</a><br /><i>Fig.</i> 1.
+</span>
+  represented by AB. CD. EF. of the first Figure of the XVI. <i>Scheme</i>;
+  that their ends AAA, were very sharp, and the substance of them stiff and
+  hard, much like the substance of several kinds of Thorns and crooks
+  growing on Trees. And though they appear'd very cleer and transparent,
+  yet I could not perceive whether they were hollow or not, but to me they
+  appear'd like solid transparent bodies, without any cavity in them;
+  whether, though they might not be a kind of Cane, fill'd with some
+  transparent liquor which was hardned (because the Cod which I had was
+  very dry) I was not able to examine.</p>
+
+  <p>Now, being such stiff, sharp bodies, it is easie to conceive, how with
+  rubbing they might easily be thrust into the tender parts of the skin,
+  and there, by reason of their exceeding fineness and driness, not create
+  any considerable trouble or pain, till by remaining in those places
+  moistned with the humours of the body, some caustick part sticking on
+  them, or residing within them might be dissolv'd and
+  mix'd with the ambient juices of that place, and thereby those
+  <i>fibres</i> and tender parts adjoyning become affected, and as it were
+  corroded by it; whence, while that action lasts, the pains created are
+  pretty sharp and pungent, though small, which is the essential property
+  of an itching one.</p>
+
+  <p>That the pain also caused by the stinging of a Flea, a Gnat, a Flie, a
+  Wasp, and the like, proceeds much from the very same cause, I elsewhere
+  in their proper places endeavour to manifest. The stinging also of shred
+  Hors-hair, which in meriment is often strew'd between the sheets of a
+  Bed, seems to proceed from the same cause.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXVII" id="obsXXVII">XXVII</a>. <i>Of the </i>Beard<i> of a wilde </i>Oat<i>, and the use that
+may be made of it for exhibiting always to the Eye the temperature
+of the Air, as to driness and moisture.</i></h3>
+
+  <p>This Beard of a wild <i>Oat</i>, is a body of a very curious
+  structure, though to the naked Eye it appears very slight, and
+  inconsiderable, it being only a small black or brown Beard or Bristle,
+  which grows out of the side of the inner Husk that covers the Grain of a
+  wild <i>Oat</i>; the whole length of it, when put in Water, so that it
+  may extend it self to its full length, is not above an Inch and a half,
+  and for the most part somewhat shorter, but when the Grain is ripe, and
+  very dry, which is usualy in the Moneths of <i>July</i>, and
+  <i>August</i>, this Beard is bent somewhat below the middle, namely,
+  about 2/5 from the bottom of it, almost to a right Angle, and the under
+  part of it is wreath'd lik a With; the substance of it is very brittle
+  when dry, and it will very easily be broken from the husk on which it
+  grows.</p>
+
+  <p>If you take one of these Grains, and wet the Beard in Water, you will
+  presently see the small bended top to turn and move round, as if it were
+  sensible; and by degrees, if it be continued wet enough, the joint or
+  knee will streighten it self; and if it be suffer'd to dry again, it will
+  by degrees move round another way, and at length bend again into its
+  former posture.</p>
+
+  <p>If it be view'd with an ordinary single <i>Microscope</i>, it will
+  appear like a small wreath'd Sprig, with two clefts; and if wet as
+  before, and then look'd on with this <i>Microscope</i>, it will appear to
+  unwreath it self, and by degrees, to streighten its knee, and the two
+  clefts will become streight, and almost on opposite sides of the small
+  cylindrical body.</p>
+
+  <p>If it be continued to be look'd on a little longer with a
+  <i>Microscope</i>, it will within a little while begin to wreath it self
+  again, and soon after return to its former posture, bending it self again
+  neer the middle, into a kind of knee or angle.</p>
+
+<span class="sidenote">
+<a href="images/scheme-15.png" target="_blank"><i>Schem.</i> 15.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>Several of those bodies I examin'd with larger <i>Microscopes</i>, and
+  there found them much of the make of those two long wreath'd cylinders
+  delineated in the second Figure of the 15. <i>Scheme</i>, which two
+  cylinders represent the wreathed part broken
+  into two pieces, whereof the end AB is to be suppos'd to have join'd to
+  the end CD, so that EACF does represent the whole wreath'd part of the
+  Beard, and EG a small piece of the upper part of the Beard which is
+  beyond the knee, which as I had not room to insert, so was it not very
+  considerable, either for its form, or any known property; but the under
+  or wreathed part is notable for both: As to its form, it appear'd, if it
+  were look'd on side-ways, almost like a Willow, or a small tapering rod
+  of <i>Hazel</i>, the lower or bigger half of which onely, is twisted
+  round several times, in some three, in others more, in others less,
+  according to the bigness and maturity of the Grain on which it grew, and
+  according to the driness and moisture of the ambient Air, as I shall shew
+  more at large by and by.</p>
+
+  <p>The whole outward Superficies of this Cylindrical body is curiously
+  adorned or fluted with little channels, and interjacent ridges, or little
+  <i>protuberances</i> between them, which run the whole length of the
+  Beard, and are streight where the Beard is not twisted, and wreath'd
+  where it is, just after the same manner: each of those sides is beset
+  pretty thick with small Brides or Thorns, somewhat in form resembling
+  that of <i>Porcupines</i> Quills, such as <i>aaaaa</i> in the Figure; all
+  whose points are directed like so many Turn-pikes towards the small end
+  or top of the Beard, which is the reason, why, if you endeavour to draw
+  the Beard between your fingers the contrary way, you will find it to
+  stick, and grate, as it were, against the skin.</p>
+
+  <p>The proportion of these small conical bodies <i>aaaaa</i> to that
+  whereon they grow, the Figure will sufficiently shew, as also their
+  manner of growing, their thickness, and neerness to each other, as, that
+  towards the root or bottom of the Beard, they are more thin, and much
+  shorter, insomuch that there is usually left between the top of the one,
+  and the bottom of that next above it, more then the length of one of
+  them, and that towards the top of the Beard they grow more thick and
+  close (though there be fewer ridges) so that the root, and almost half
+  the upper are hid by the tops of those next below them.</p>
+
+  <p>I could not perceive any <i>transverse</i> pores, unless the whole
+  wreath'd part were separated and cleft, in those little channels, by the
+  wreathing into so many little strings as there were ridges, which was
+  very difficult to determine; but there were in the wreathed part two very
+  conspicuous channels or clefts, which were continued from the bottom F to
+  the elbow bow EH or all along the part which was wreath'd, which seem'd
+  to divide the wreath'd Cylinder into two parts, a bigger and a less; the
+  bigger was that which was at the <i>convex</i> side of the knee, namely,
+  on the side A, and was wreath'd by OOOOO; this, as it seem'd the broader,
+  so did it also the longer, the other PPPPP, which was usually purs'd or
+  wrinckled in the bending of the knee, as about E, seem'd both the shorter
+  and narrower, so that at first I thought the wreathing and unwreathing of
+  the Beard might have been caus'd by the shrinking or swelling of that
+  part; but upon further examination, I found that the clefts, KK, LL, were
+  stuft up with a kind of Spongie substance, which, for the most part, was
+  very conspicuous neer the knee, as in the
+  cleft KK, when the Beard was dry; upon the discovery of which, I began to
+  think, that it was upon the swelling of this porous pith upon the access
+  of moisture or water that the Beard, being made longer in the midst, was
+  streightned, and by the shrinking or subsiding of the parts of that
+  Spongie substance together, when the water or moisture was exhal'd or
+  dried, the pith or middle parts growing shorter, the whole became
+  twisted.</p>
+
+  <p>But this I cannot be positive in, for upon cutting the wreath'd part
+  in many places transversly, I was not so well satisfy'd with the shape
+  and manner of the pores of the pith; for looking on these transverse
+  Sections with a very good <i>Microscope</i>, I found that the ends of
+<span class="sidenote">
+<a href="images/scheme-15.png" target="_blank"><i>Schem.</i> 15.</a><br /><i>Fig.</i> 3.
+</span>
+  those transverse Sections appear'd much of the manner of the third Figure
+  of the 15. <i>scheme</i> ABCFE, and the middle of pith CC, seem'd very
+  full of pores indeed, but all of them seem'd to run the long-ways.</p>
+
+  <p>This Figure plainly enough shews in what manner those clefts, K and L
+  divided the wreath'd Cylinder into two unequal parts, and also of what
+  kind of substance the whole body consists; for by cutting the same Beard
+  in many places, with transverse Sections, I found much the same
+  appearance with this express'd; so that those pores seem to run, as in
+  most other such Cany bodies, the whole length of it.</p>
+
+  <p>The clefts of this body KK, and LL, seem'd (as is also express'd in
+  the Figure) to wind very oddly in the inner part of the wreath, and in
+  some parts of them, they seem'd stuffed, as it were, with that Spongie
+  substance, which I just now described.</p>
+
+  <p>This so oddly constituted Vegetable substance, is first (that I have
+  met with) taken notice of by <i>Baptista Porta</i>, in his <i>Natural
+  Magick</i>, as a thing known to children and Juglers, and it has been
+  call'd by some of those last named persons, the better to cover their
+  cheat, the Legg of an <i>Arabian Spider</i>, or the Legg of an inchanted
+  <i>Egyptian fly</i>, and has been used by them to make a small Index,
+  Cross, or the like, to move round upon the wetting of it with a drop of
+  Water, and muttering certain words.</p>
+
+  <p>But the use that has been made of it, for the discovery of the various
+  constitutions of the Air, as to driness and moistness, is incomparably
+  beyond any other, for this it does to admiration: The manner of
+  contriving it so, as to perform this great effect, is onely thus:</p>
+
+  <p>Provide a good large Box of Ivory, about four Inches over, and of what
+  depth you shall judge convenient (according to your intention of making
+  use of one, two, three, or more of these small Beards, ordered in the
+  manner which I shall by and by describe) let all the sides of this Box be
+  turned of Basket-work (which here in <i>London</i> is easily enough
+  procur'd) full of holes, in the manner almost of a Lettice, the bigger,
+  or more the holes are, the better, that so the Air may have the more free
+  passage to the inclosed Beard, and may the more easily pass through the
+  Instrument; it will be better yet, though not altogether so handsom, if
+  insteed of the Basket-work on the sides of the Box, the bottom and top of
+  the Box be join'd together onely with three or four small Pillars, after
+<span class="sidenote">
+<a href="images/scheme-15.png" target="_blank"><i>Schem.</i> 15.</a><br /><i>Fig.</i> 4.
+</span>
+  the manner represented in the 4. Figure of the 15.
+  <i>Scheme</i>. Or, if you intend to make use of many of these small
+  Beards join'd together, you may have a small long Case of Ivory, whose
+  sides are turn'd of Basket-work, full of holes, which may be screw'd on
+  to the underside of a broad Plate of Ivory, on the other side of which is
+  to be made the divided Ring or Circle, to which divisions the pointing of
+  the Hand or Index, which is moved by the conjoin'd Beard, may shew all
+  the <i>Minute</i> variations of the Air.</p>
+
+  <p>There may be multitudes of other ways for contriving this small
+  Instrument, so as to produce this effect, which any one may, according to
+  his peculiar use, and the exigency of his present occasion, easily enough
+  contrive and take, on which I shall not therefore insist. The whole
+  manner of making any one of them is thus: Having your Box or frame AABB,
+  fitly adapted for the free passage of the Air through it, in the midst of
+  the bottom BBB, you must have a very small hole C, into which the lower
+  end of the Beard is to be fix'd, the upper end of which Beard <i>ab</i>,
+  is to pass through a small hole of a Plate, or top AA, if you make use
+  onely of a single one, and on the top of it <i>e</i>, is to be fix'd a
+  small and very light <i>Index</i> <i>fg</i>, made of a very thin sliver
+  of a Reed or Cane; but if you make use of two or more Beards, they must
+  be fix'd and bound together, either with a very fine piece of Silk, or
+  with a very small touch of hard Wax, or Glew, which is better, and the
+  <i>Index</i> <i>fg</i>, is to be fix'd on the top of the second, third,
+  or fourth in the same manner as on the single one.</p>
+
+  <p>Now, because that in every of these contrivances, the <i>Index</i>
+  <i>fg</i>, will with some temperatures of Air, move two, three, or more
+  times round, which without some other contrivance then this, will be
+  difficult to distinguish, therefore I thought of this Expedient: The
+  <i>Index</i> or <i>Hand</i> <i>fg</i>, being rais'd a pretty way above
+  the surface of the Plate AA, fix in at a little distance from the middle
+  of it a small Pin <i>h</i>, so as almost to touch the surface of the
+  Plate AA, and then in any convenient place of the surface of the Plate,
+  fix a small Pin, on which put on a small piece of Paper, or thin
+  Past-board, Vellom, or Parchment, made of a convenient cize, and shap'd
+  in the manner of that in the Figure express'd by <i>ik</i>, so that
+  having a convenient number of teeth every turn or return of the Pin
+  <i>h</i>, may move this small indented Circle, a tooth forward or
+  backwards, by which means the teeth of the Circle, being mark'd, it will
+  be thereby very easie to know certainly, how much variation any change of
+  weather will make upon the small wreath'd body. In the making of this
+  Secundary Circle of Vellom, or the like, great care is to be had, that it
+  be made exceeding light, and to move very easily, for otherwise a small
+  variation will spoil the whole operation. The Box may be made of Brass,
+  Silver, Iron, or any other substance, if care be taken to make it open
+  enough, to let the Air have a sufficiently free access to the Beard. The
+  <i>Index</i> also may be various ways contrived, so as to shew both the
+  number of the revolutions it makes, and the <i>Minute</i> divisions of
+  each revolution.</p>
+
+  <p>I have made several trials and Instruments for discovering the driness
+  and moisture of the Air with this little wreath'd body, and find it to
+  vary exceeding sensibly with the least change in the constitution of the
+  Air, as to driness and moisture, so that with one
+  breathing upon it, I have made it untwist a whole bout, and the
+  <i>Index</i> or <i>Hand</i> has shew'd or pointed to various divisions on
+  the upper Face or Ring of the Instrument, according as it was carried
+  neerer and neerer to the fire, or as the heat of the Sun increased upon
+  it.</p>
+
+  <p>Other trials I have made with Gut-strings, but find them nothing neer
+  so sensible, though they also may be so contriv'd as to exhibit the
+  changes of the Air, as to driness and moisture, both by their stretching
+  and shrinking in length, and also by their wreathing and unwreathing
+  themselves; but these are nothing neer so exact or so tender, for their
+  varying property will in a little time change very much. But there are
+  several other Vegetable substances that are much more sensible then even
+  this Beard of a wilde <i>Oat</i>; such I have found the Beard of the seed
+  of Musk-grass, or <i>Geranium moschatum</i>, and those of other kinds of
+  <i>Cranes-bil</i> seeds, and the like. But always the smaller the
+  wreathing substance be, the more sensible is it of the mutations of the
+  Air, a conjecture at the reason of which I shall by and by add.</p>
+
+  <p>The lower end of this wreath'd Cylinder being stuck upright in a
+  little soft Wax, so that the bended part or <i>Index</i> of it lay
+  <i>horizontal</i>, I have observ'd it always with moisture to unwreath it
+  self from the East (For instance) by the South to the West, and so by the
+  North to the East again, moving with the Sun (as we commonly say) and
+  with heat and drouth to re-twist; and wreath it self the contrary way,
+  namely, from the East, (for instance) by the North to the West, and so
+  onwards.</p>
+
+  <p>The cause of all which <i>Phænomena</i>, seems to be the differing
+  texture of the parts of these bodies, each of them (especially the Beard
+  of a wilde <i>Oat</i>, and of <i>Mosk-grass</i> seed) seeming to have two
+  kind of substances, one that is very porous, loose, and spongie, into
+  which the watry steams of the Air may be very easily forced, which will
+  be thereby swell'd and extended in its dimensions, just as we may observe
+  all kind of Vegetable substance upon steeping in water to swell and grow
+  bigger and longer. And a second that is more hard and close, into which
+  the water can very little, or not at all penetrate, this therefore
+  retaining always very neer the same dimensions, and the other stretching
+  and shrinking, according as there is more or less moisture or water in
+  its pores, by reason of the make and shape of the parts, the whole body
+  must necessarily unwreath and wreath it self.</p>
+
+  <p>And upon this Principle, it is very easie to make several sorts of
+  contrivances that should thus wreath and unwreath themselves, either by
+  heat and cold, or by driness and moisture, or by any greater or less
+  force, from whatever cause it proceed, whether from gravity or weight, or
+  from wind which is motion of the Air, or from some springing body, or the
+  like.</p>
+
+  <p>This, had I time, I should enlarge much more upon; for it seems to me
+  to be the very first footstep of <i>Sensation</i>, and Animate motion,
+  the most plain, simple, and obvious contrivance that Nature has made use
+  of to produce a motion; next to that of Rarefaction and Condensation by
+  heat and cold. And were this Principle very well
+  examin'd, I am very apt to think, it would afford us a very great help to
+  find out the <i>Mechanism</i> of the Muscles, which indeed, as farr as I
+  have hitherto been able to examine, seems to me not so very perplex as
+  one might imagine, especially upon the examination which I made of the
+  Muscles of <i>Crabs</i>, <i>Lobsters</i>, and several sorts of large
+  Shell-fish, and comparing my Observations on them, with the circumstances
+  I observ'd in the muscles of terrestrial Animals.</p>
+
+  <p>Now, as in this Instance of the Beard of a wilde <i>Oat</i>, we see
+  there is nothing else requisite to make it wreath and unwreath it self,
+  and to streighten and bend its knee, then onely a little breath of moist
+  or dry Air, or a small <i>atome</i> almost of water or liquor, and a
+  little heat to make it again evaporate, for, by holding this Beard,
+  plac'd and fix'd as I before directed, neer a Fire, and dipping the tip
+  of a small shred of Paper in well rectify'd spirit of Wine, and then
+  touching the wreath'd <i>Cylindrical</i> part, you may perceive it to
+  untwist it self; and presently again, upon the <i>avolation</i> of the
+  spirit, by the great heat, it will re-twist it self, and thus will it
+  move forward and backwards as oft as you repeat the touching it with the
+  spirit of Wine; so may, perhaps, the shrinking and relaxing of the
+  muscles be by the influx and evaporation of some kind of liquor or juice.
+  But of this Enquiry I shall add more elsewhere.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXVIII" id="obsXXVIII">XXVIII</a>. <i>Of the Seeds of </i>Venus<i> looking-glass, or </i>Corn<i>
+Violet.</i></h3>
+
+  <p>From the Leaves, and Downs, and Beards of Plants, we come at last to
+  the Seeds; and here indeed seems to be the Cabinet of Nature, wherein are
+  laid up its Jewels. The providence of Nature about Vegetables, is in no
+  part manifested more, then in the various contrivances about the seed,
+  nor indeed is there in any part of the Vegetable so curious carvings, and
+  beautifull adornments, as about the seed; this in the larger sorts of
+  seeds is most evident to the eye; nor is it lest manifest through the
+  <i>Microscope</i>, in those seeds whose shape and structure, by reason of
+  their smalness, the eye is hardly able to distinguish.</p>
+
+  <p>Of these there are multitudes, many of which I have observ'd through a
+  <i>Microscope</i>, and find, that they do, for the most part, every one
+  afford exceeding pleasant and beautifull objects. For besides those that
+  have various kinds of carv'd surfaces, there are other that have smooth
+  and perfectly polish'd surfaces, others a downy hairy surface; some are
+  cover'd onely with a skin, others with a kind of shell, others with both,
+  as is observable also in greater seeds.</p>
+
+  <p>Of these seeds I have onely described four sorts which may serve as a
+  <i>specimen</i> of what the inquisitive observers are likely to find
+<span class="sidenote">
+<a href="images/scheme-17.png" target="_blank"><i>Schem.</i> 17.</a>
+</span>
+  among the rest. The first of these seeds which are described in the 17.
+  <i>Scheme</i>, are those of Corn-Violets, the seed is very small, black,
+  and shining, and, to the naked eye, looks almost like a very small Flea;
+  But through the <i>Microscope</i>, it appears a large body,
+  cover'd with a tough thick and bright reflecting skin very irregularly
+  shrunk and pitted, insomuch that it is almost an impossibility to find
+  two of them wrinkled alike, so great a variety may there be even in this
+  little seed.</p>
+
+  <p>This, though it appear'd one of the most promising seeds for beauty to
+  the naked eye, yet through the <i>Microscope</i> it appear'd but a rude
+  mishapen seed, which I therefore drew, that I might thereby manifest how
+  unable we are by the naked eye to judge of beauteous or less curious
+  <i>microscopical</i> Objects; cutting some of them in sunder, I observ'd
+  them to be fill'd with a greenish yellow pulp, and to have a very thick
+  husk, in proportion to the pulp.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXIX" id="obsXXIX">XXIX</a>. <i>Of the Seeds of </i>Tyme<i>.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-18.png" target="_blank"><i>Schem.</i> 18.</a>
+</span>
+  <p>These pretty fruits here represented, in the 18. <i>Scheme</i>, are
+  nothing else, but nine several seeds of Tyme; they are all of them in
+  differing posture, both as to the eye and the light; nor are they all of
+  them exactly of the same shape, there being a great variety both in the
+  bulk and figure of each seed; but they all agreed in this, that being
+  look'd on with a <i>Microscope</i>, they each of them exactly resembled a
+  Lemmon or Orange dry'd; and this both in shape and colour. Some of them
+  are a little rounder, of the shape of an Orange, as A and B, they have
+  each of them a very conspicuous part by which they were join'd to their
+  little stalk, and one of them had a little piece of stalk remaining on;
+  the opposite side of the seed, you may perceive very plainly by the
+  Figure, is very copped and prominent, as is very usual in Lemmons; which
+  prominencies are express'd in D, E and F.</p>
+
+  <p>They seem'd each of them a little creas'd or wrinckled, but E was very
+  conspicuously furrow'd, as if the inward make of this seed had been
+  somewhat like that of a Lemmon also, but upon dividing several seeds with
+  a very sharp Pen-knife, and examining them afterward, I found their make
+  to be in nothing but bulk differing from that of Peas, that is, to have a
+  pretty thick coat, and all the rest an indifferent white pulp, which
+  seem'd very close; so that it seems Nature does not very much alter her
+  method in the manner of inclosing and preserving the vital Principle in
+  the seed, in these very small grains, from that of Beans, Peas,
+  <i>&amp;c.</i></p>
+
+  <p>The Grain affords a very pretty Object for the <i>Microscope</i>,
+  namely, a Dish of Lemmons plac'd in a very little room; should a Lemmon
+  or Nut be proportionably magnify'd to what this seed of Tyme is, it would
+  make it appear as bigg as a large Hay-reek and it would be no great
+  wonder to see <i>Homers Iliads</i>, and <i>Homer</i> and all, cramm'd
+  into such a Nutshell. We may perceive even in these small Grains, as well
+  as in greater, how curious and carefull Nature is in preserving the
+  seminal principle of Vegetable bodies, in what delicate, strong and most
+  convenient Cabinets she lays them and closes them in
+  a pulp for their safer protection from outward dangers, and for the
+  supply of convenient alimental juice, when the heat of the Sun begins to
+  animate and move these little <i>automatons</i> or Engines; as if she
+  would, from the ornaments wherewith she has deckt these Cabinets, hint to
+  us, that in them she has laid up her Jewels and Master-pieces. And this,
+  if we are but diligent in observing, we shall find her method throughout.
+  There is no curiosity in the Elemental kingdom, if I may so call the
+  bodies of Air, Water, Earth, that are comparable in form to those of
+  Minerals, Air and Water having no form at all, unless a potentiality to
+  be form'd into Globules; and the clods and parcels of Earth are all
+  irregular, whereas in Minerals she does begin to <i>Geometrize</i>, and
+  practise, as 'twere, the first principles of <i>Mechanicks</i>, shaping
+  them of plain regular figures, as triangles, squares, <i>&amp;c.</i> and
+  <i>tetraedrons</i>, cubes, <i>&amp;c.</i> But none of their forms are
+  comparable to the more compounded ones of Vegetables; For here she goes a
+  step further, forming them both of more complicated shapes, and adding
+  also multitudes of curious Mechanick contrivances in their structure; for
+  whereas in Vegetables there was no determinate number of the leaves or
+  branches, nor no exacly certain figure of leaves, or flowers, or seeds,
+  in Animals all those things are exactly defin'd and determin'd; and
+  where-ever there is either an excess or defect of those determinate parts
+  or limbs, there has been some impediment that has spoil'd the principle
+  which was most regular: Here we shall find, not onely most curiously
+  compounded shapes, but most stupendious Mechanisms and contrivances, here
+  the ornaments are in the highest perfection, nothing in all the Vegetable
+  kingdom that is comparable to the deckings of a Peacock; nay, to the
+  curiosity of any feather, as I elsewhere shew; nor to that of the
+  smallest and most despicable Fly. But I must not stay on these
+  speculations, though perhaps it were very well worth while for one that
+  had leisure, to see what Information may be learn'd of the nature, or
+  use, or virtues of bodies, by their several forms and various
+  excellencies and properties. Who knows but <i>Adam</i> might from some
+  such contemplation, give names to all creatures? If at least his names
+  had any significancy in them of the creatures nature on which he impos'd
+  it; as many (upon what grounds I know not) have suppos'd: And who knows,
+  but the Creator may, in those characters, have written and engraven many
+  of his most mysterious designs and counsels, and given man a capacity,
+  which, assisted with diligence and industry, may be able to read and
+  understand them. But not to multiply my digression more then I can the
+  time, I will proceed to the next, which is,</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXX" id="obsXXX">XXX</a>. <i>Of the Seeds of </i>Poppy<i>.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-19.png" target="_blank"><i>Schem.</i> 19.</a>
+</span>
+  <p>The small seeds of Poppy, which are described in the 19.
+  <i>Scheme</i>, both for their smalness, multiplicity and prettiness, as
+  also for their admirable soporifick quality, deserve to be taken notice
+  of among the other <i>microscopical</i> seeds of
+  Vegetables: For first, though they grow in a Case or Hive oftentimes
+  bigger then one of these Pictures of the <i>microscopical</i> appearance,
+  yet are they for the most part so very little, that they exceed not the
+  bulk of a small Nitt, being not above 1/32 part of an Inch in Diameter,
+  whereas the Diameter of the Hive of them oftentimes exceeds two Inches,
+  so that it is capable of containing near two hundred thousand, and so in
+  all likelihood does contain a vast quantity, though perhaps not that
+  number. Next, for their prettiness, they may be compar'd to any
+  <i>microscopical</i> seed I have yet seen; for they are of a dark
+  brownish red colour, curiously Honey-comb'd all over with a very pretty
+  variety of Net-work, or a small kind of imbosment of very orderly rais'd
+  ridges, the surface of them looking not unlike the inside of a Beev's
+  stomack. But that which makes it most considerable of all, is, the
+  medicinal virtues of it, which are such as are not afforded us by any
+  Mineral preparation; and that is for the procuring of sleep, a thing as
+  necessary to the well-being of a creature as his meat, and that which
+  refreshes both the voluntary and rational faculties, which, whil'st this
+  affection has seis'd the body, are for the most part unmov'd, and at
+  rest. And, methinks, Nature does seem to hint some very notable virtue or
+  excellency in this Plant from the curiosity it has bestow'd upon it.
+  First, in its flower, it is of the highest scarlet-Dye, which is indeed
+  the prime and chiefest colour, and has been in all Ages of the world most
+  highly esteem'd: Next, it has as much curiosity shew'd also in the husk
+  or case of the seed, as any one Plant I have yet met withall; and
+  thirdly, the very seeds themselves, the <i>Microscope</i> discovers to be
+  very curiously shap'd bodies; and lastly, Nature has taken such abundant
+  care for the propagation of it, that one single seed grown into a Plant,
+  is capable of bringing some hundred thousands of seeds.</p>
+
+  <p>It were very worthy some able man's enquiry whether the intention of
+  Nature, as to the secundary end of Animal and Vegetable substances might
+  not be found out by some such characters and notable impressions as
+  these, or from divers other circumstances, as the figure, colour, place,
+  time of flourishing, springing and fading, duration, taste, smell,
+  <i>&amp;c.</i> For if such there are (as an able <i>Physician</i> upon
+  good grounds has given me cause to believe) we might then, insteed of
+  studying Herbals (where so little is deliver'd of the virtues of a Plant,
+  and less of truth) have recourse to the Book of Nature it self, and there
+  find the most natural, usefull, and most effectual and specifick
+  Medicines, of which we have amongst Vegetables, two very noble Instances
+  to incourage such a hope, the one of the <i>Jesuite powder</i> for the
+  cure of <i>intermitting Feavers</i>, and the other of the juice of
+  <i>Poppy</i> for the curing the defect of sleeping.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXI" id="obsXXXI">XXXI</a>. <i>Of </i>Purslane-seed<i>.</i></h3>
+
+  <p>The Seeds of <i>Purslane</i> seem of very notable shapes, appearing
+  through the <i>Microscope</i> shap'd somewhat like a <i>nautilus</i> or
+<span class="sidenote">
+<a href="images/scheme-20.png" target="_blank"><i>Schem.</i> 20.</a>
+</span>
+  <i>Porcelane</i> shell, as may be seen in the XX. <i>Scheme</i>, it being
+  a small body, coyl'd round in the manner of a Spiral, at the greater end
+  whereof, which represents the mouth or orifice of the Shell, there is
+  left a little white transparent substance, like a skin, represented by
+  BBBB, which seems to have been the place whereunto the stem was join'd.
+  The whole surface of this <i>Coclea</i> or Shell, is cover'd over with
+  abundance of little <i>prominencies</i> or buttons very orderly rang'd
+  into Spiral rows, the shape of each of which seem'd much to resemble a
+  Wart upon a mans hand. The order, variety, and curiosity in the shape of
+  this little seed, makes it a very pleasant object for the
+  <i>Microscope</i>, one of them being cut asunder with a very sharp
+  Penknife, discover'd this carved Casket to be of a brownish red, and
+  somewhat transparent substance, and manifested the inside to be fill'd
+  with a whitish green substance or pulp, the Bed wherein the seminal
+  principle lies <i>invelop'd</i>.</p>
+
+  <p>There are multitudes of other seeds which in shape represent or
+  imitate the forms of divers other sorts of Shells: as the seed of
+  <i>Scurvy-grass</i> very much resembles the make of a <i>Concha
+  Venerea</i>, a kind of Purcelane Shell; others represent several sorts of
+  larger fruits, sweat Marjerome and Pot-marjerome represent Olives. Carret
+  seeds are like a cleft of a Coco-Nut Husk, others are like Artificial
+  things, as Succory seeds are like a Quiver full of Arrows, the seeds of
+  <i>Amaranthus</i> are of an exceeding lovely shape, somewhat like an Eye:
+  The skin of the black and shrivled seeds of Onyons and Leeks, are all
+  over knobbed like a Seals skin. Sorrel has a pretty black shining
+  three-square seed, which is picked at both ends with three ridges, that
+  are bent the whole length of it. It were almost endless to reckon up the
+  several shapes, they are so many and so various; Leaving them therefore
+  to the curious observer, I shall proceed to the Observations on the parts
+  of Animals.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXII" id="obsXXXII">XXXII</a>. <i>Of the Figure of several sorts of </i>Hair<i>, and of
+the texture of the </i>skin<i>.</i></h3>
+
+  <p>Viewing some of the Hairs of my Head with a very good
+  <i>Microscope</i>, I took notice of these particulars:</p>
+
+  <p>1. That they were, for the most part, <i>Cylindrical</i>, some of them
+  were somewhat <i>Prismatical</i>, but generally they were very neer
+<span class="sidenote">
+<a href="images/scheme-05.png" target="_blank"><i>Schem.</i> 5.</a><br /><i>Fig.</i> 2.
+</span>
+  round, such as are represented in the second Figure of the 5.
+  <i>Scheme</i>, by the <i>Cylinders</i> EEE. nor could I find any that had
+  sharp angules.</p>
+
+  <p>2. That that part which was next the top, was bigger then that which
+  was neerer the root.</p>
+
+  <p>3. That they were all along from end to end transparent, though not
+  very cleer, the end next the root appearing like a black transparent
+  piece of Horn, the end next the top more brown, somewhat like transparent
+  Horn.</p>
+
+  <p>4. That the root of the Hairs were pretty smooth, tapering inwards,
+  almost like a Parsneb; nor could I find that it had any filaments, or any
+  other vessels, such as the <i>fibres</i> of Plants.</p>
+
+  <p>5. That the top when split (which is common in long Hair) appear'd
+  like the end of a stick, beaten till it be all flitter'd, there being not
+  onely two splinters, but sometimes half a score and more.</p>
+
+  <p>6. That they were all, as farr as I was able to find, solid
+  <i>Cylindrical</i> bodies, not pervious, like a Cane or Bulrush; nor
+  could I find that they had any Pith, or distinction of Rind, or the like,
+  such as I had observ'd in Horse-hairs, the Bristles of a Cat, the
+  <i>Indian</i> Deer's Hair, <i>&amp;c.</i></p>
+
+<h3><i>Observations on several other sorts of </i>Hair<i>.</i></h3>
+
+  <p>For the Brisles of a Hogg, I found them to be first a hard transparent
+  horny substance, without the least appearance of pores or holes in it;
+  and this I try'd with the greatest care I was able, cutting many of them
+  with a very sharp Razor, so that they appear'd, even in the Glass, to
+  have a pretty smooth surface, but somewhat waved by the sawing to and fro
+  of the Razor, as is visible in the end of the <i>Prismatical</i> body A
+  of the same Figure; and then making trials with causing the light to be
+  cast on them all the various ways I could think of, that was likely to
+  make the pores appear, if there had been any, I was not able to discover
+  any.</p>
+
+  <p>Next, the Figure of the Brisles was very various, neither perfectly
+  round, nor sharp edg'd, but <i>Prismatical</i>, with divers sides, and
+  round angles, as appears in the Figure A. The bending of them in any part
+  where they before appear'd cleer, would all flaw them, and make them look
+  white.</p>
+
+  <p>The Mustacheos of a Cat (part of one of which is represented by the
+  short <i>Cylinder</i> B of the same Figure) seem'd to have, all of them
+  that I observ'd, a large pith in the middle, like the pith of an Elder,
+  whose texture was so close, that I was not able to discover the least
+  sign of pores; and those parts which seem to be pores, as they appear'd
+  in one position to the light, in another I could find a manifest
+  reflection to be cast from them.</p>
+
+  <p>This I instance in, to hint that it is not safe to conclude any thing
+  to be positively this or that, though it appear never so plain and likely
+  when look'd on with a <i>Microscope</i> in one posture, before the same
+  be examin'd by placing it in several other positions.</p>
+
+  <p>And this I take to be the reason why many have believed and asserted
+  the Hairs of a man's head to be hollow, and like so many small pipes
+  perforated from end to end.</p>
+
+  <p>Now, though I grant that by an <i>Analogie</i> one may suppose them
+  so, and from the <i>Polonian</i> disease one
+  may believe them such, yet I think we have not the least encouragement to
+  either from the <i>Microscope</i>, much less positively to assert them
+  such. And perhaps the very essence of the <i>Plica Polonica</i> may be
+  the hairs growing hollow, and of an unnatural constitution.</p>
+
+  <p>And as for the <i>Analogie</i>, though I am apt enough to think that
+  the hairs of several Animals may be perforated somewhat like a Cane, or
+  at least have a kind of pith in them, first, because they seem as 'twere
+  a kind of Vegetable growing on an Animal, which growing, they say,
+  remains a long while after the Animal is dead, and therefore should like
+  other Vegetables have a pith; and secondly, because Horns and Feathers,
+  and Porcupine's Quils, and Cats Bristles, and the long hairs of Horses,
+  which come very neer the nature of a mans hair, seem all of them to have
+  a kind of pith, and some of them to be porous, yet I think it not (in
+  these cases, where we have such helps for the sense as the
+  <i>Microscope</i> affords) safe concluding or building on more then we
+  sensibly know, since we may, with examining, find that Nature does in the
+  make of the same kind of substance, often vary her method in framing of
+  it: Instances enough to confirm this we may find in the Horns of several
+  creatures: as what a vast difference is there between the Horns of an
+  Oxe, and those of some sorts of Staggs as to their shape? and even in the
+  hairs of several creatures, we find a vast difference, as the hair of a
+  man's head seems, as I said before, long, <i>Cylindrical</i> and sometime
+  a little <i>Prismatical</i>, solid or impervious, and very small; the
+  hair of an <i>Indian</i> Deer (a part of the middle of which is described
+<span class="sidenote">
+<a href="images/scheme-05.png" target="_blank"><i>Schem.</i> 5.</a><br /><i>Fig.</i> 3.
+</span>
+  in the third Figure of the fifth <i>Scheme</i>, marked with F) is bigger
+  in compass through all the middle of it, then the Bristle of an Hogg, but
+  the end of it is smaller then the hair of any kind of Animal (as may be
+  seen by the Figure G) the whole belly of it, which is about two or three
+  Inches long, looks to the eye like a thread of course Canvass, that has
+  been newly unwreath'd, it being all wav'd or bended to and fro, much
+  after that manner, but through the <i>Microscope</i>, it appears all
+  perforated from side to side, and Spongie, like a small kind of spongy
+  Coral, which is often found upon the <i>English</i> shores; but though I
+  cut it transversly, I could not perceive that it had any pores that ran
+  the long-way of the hair: the long hairs of Horses CC and D, seem
+  <i>Cylindrical</i> and somewhat pithy; the Bristles of a Cat B, are
+  conical and pithy: the Quils of Porcupines and Hedghoggs, being cut
+  transversly, have a whitish pith, in the manner of a Starr, or
+  Spur-rowel: Piggs-hair (A) is somewhat <i>triagonal</i>, and seems to
+  have neither pith nor pore: And other kinds of hair have quite a
+  differing structure and form. And therefore I think it no way agreeable
+  to a true natural Historian, to pretend to be so sharp-sighted, as to see
+  what a pre-conceiv'd <i>Hypothesis</i> tells them should be there, where
+  another man, though perhaps as seeing, but not forestall'd, can discover
+  no such matter.</p>
+
+  <p>But to proceed; I observ'd several kind of hairs that had been Dyed,
+  and found them to be a kind of horny <i>Cylinder</i>, being of much about
+  the transparency of a pretty cleer piece of Oxe horn; these appear'd
+  quite throughout ting'd with the colours they
+  exhibited. And 'tis likely, that those hairs being boyl'd or steep'd in
+  those very hot ting'd liquors in the Dye-fat, And the substance of the
+  hair being much like that of an Oxes Horn, the penetrant liquor does so
+  far mollifie and soften the substance, that it sinks into the very center
+  of it, and so the ting'd parts come to be mix'd and united with the very
+  body of the hair, and do not (as some have thought) only stick on upon
+  the outward surface. And this, the boiling of Horn will make more
+  probable; for we shall find by that action, that the water will insinuate
+  it self to a pretty depth within the surface of it, especially if this
+  penetrancy of the water be much helped by the Salts that are usually
+  mix'd with the Dying liquors. Now, whereas Silk may be dyed or ting'd
+  into all kind of colours without boiling or dipping into hot liquors, I
+  ghess the reason to be two-fold: First, because the filaments, or small
+  cylinders of Silk, are abundantly smaller and finer, and so have a much
+  less depth to be penetrated then most kind of hairs; and next, because
+  the substance or matter of Silk, is much more like a Glew then the
+  substance of Hair is. And that I have reason to suppose: First, because
+  when it is spun or drawn out of the Worm, it is a perfect glutinous
+  substance, and very easily sticks and cleaves to any adjacent body, as I
+  have several times observed, both in Silk-worms and Spiders. Next,
+  because that I find that water does easily dissolve and mollifie the
+  substance again, which is evident from their manner of ordering those
+  bottoms or pods of the Silk-worm before they are able to unwind them. It
+  is no great wonder therefore, if those Dyes or ting'd liquors do very
+  quickly mollifie and tinge the surfaces of so small and so glutinous a
+  body. And we need not wonder that the colours appear so lovely in the
+  one, and so dull in the other, if we view but the ting'd cylinders of
+  both kinds with a good <i>Microscope</i>; for whereas the substance of
+  Hair, at best, is but a dirty duskish white somewhat transparent, the
+  filaments of Silk have a most lovely transparency and cleerness, the
+  difference between those two being not much less then that between a
+  piece of Horn, and a piece of Crystal; the one yielding a bright and
+  vivid reflection from the concave side of the cylinder, that is, from the
+  concave surface of the Air that incompasses the back-part of the
+  cylinder; the other yielding a dull and perturb'd reflection from the
+  several <i>Heterogeneous</i> parts that compose it. And this difference
+  will be manifest enough to the eye, if you get a couple of small
+  Cylinders, the smaller of Crystal Glass, the other of Horn, and then
+  varnishing them over very thinly with some transparent colour, which will
+  represent to the naked eye much the same kind of object which is
+  represented to it from the filaments of Silk and Hair by the help of the
+  <i>Microscope</i>. Now, since the threads of Silk and Serge are made up
+  of a great number of these filaments, we may henceforth cease to wonder
+  at the difference. From much the same reason proceeds the vivid and
+  lovely colours of Feathers, wherein they very farr exceed the natural as
+  well as Artificial colours of hair, of which I shall say more in its
+  proper place.</p>
+
+  <p>The Teguments indeed of creatures are all of them adapted to the
+  peculiar use and convenience of that Animal which they inwrap; and very
+  much also for the ornament and beauty of
+  it, as will be most evident to any one that shall attentively consider
+  the various kinds of cloathings wherewith most creatures are by Nature
+  invested and cover'd. Thus I have observed, that the hair or furr of
+  those Northern white Bears that inhabite the colder Regions, is exceeding
+  thick and warm: the like have I observ'd of the hair of a
+  <i>Greenland</i> Deer, which being brought alive to <i>London</i>, I had
+  the opportunity of viewing; its hair was so exceeding thick, long and
+  soft, that I could hardly with my hand, grasp or take hold of his skin,
+  and it seem'd so exceeding warm, as I had never met with any before. And
+  as for the ornamentative use of them, it is most evident in a multitude
+  of creatures, not onely for colour, as the Leopards, Cats, Rhein Deer,
+  <i>&amp;c</i>. but for the shape, as in Horses manes, Cats beards, and
+  several other of the greater sort of terrestrial Animals, but is much
+  more conspicuous, in the Vestments of Fishes, Birds, Insects, of which I
+  shall by and by give some Instances.</p>
+
+  <p>As for the skin, the <i>Microscope</i> discovers as great a difference
+  between the texture of those several kinds of Animals, as it does between
+  their hairs; but all that I have yet taken notice of, when tann'd or
+  dress'd, are of a Spongie nature, and seem to be constituted of an
+  infinite company of small long <i>fibres</i> or hairs, which look not
+  unlike a heap of Tow or Okum; every of which <i>fibres</i> seem to have
+  been some part of a Muscle, and probably, whil'st the Animal was alive,
+  might have its distinct function, and serve for the contraction and
+  relaxation of the skin, and for the stretching and shrinking of it this
+  or that way.</p>
+
+  <p>And indeed, without such a kind of texture as this, which is very like
+  that of <i>Spunk</i> it would seem very strange, how any body so strong
+  as the skin of an Animal usually is, and so close as it seems, whil'st
+  the Animal is living, should be able to suffer so great an extension any
+  ways, without at all hurting or dilacerating any part of it. But, since
+  we are inform'd by the <i>Microscope</i>, that it consists of a great
+  many small filaments, which are implicated, or intangled one within
+  another, almost no otherwise then the hairs in a lock of Wool, or the
+  flakes in a heap of Tow, though not altogether so loose, but the
+  filaments are here and there twisted, as 'twere, or interwoven, and here
+  and there they join and unite with one another, so as indeed the whole
+  skin seems to be but one piece, we need not much wonder: And though these
+  <i>fibres</i> appear not through a <i>Microscope</i> exactly jointed and
+  contex'd, as in Sponge; yet, as I formerly hinted, I am apt to think,
+  that could we find some way of discovering the texture of it, whil'st it
+  invests the living Animal, or had some very easie way of separating the
+  pulp or intercurrent juices, such as in all probability fill those
+  <i>Interstitia</i>, without dilacerating, brusing, or otherwise spoiling
+  the texture of it (as it seems to be very much by the ways of tanning and
+  dressing now us'd) we might discover a much more curious texture then I
+  have hitherto been able to find; perhaps somewhat like that of
+  Sponges.</p>
+
+  <p>That of <i>Chamoise</i> Leather is indeed very much like that of
+  <i>Spunk</i>, save onely that the <i>filaments</i> seem nothing neer so
+  even and round, nor altogether so small, nor has it so curious joints as
+  <i>Spunk</i> has, some of which I have
+  lately discover'd like those of a Sponge, and perhaps all these three
+  bodies may be of the same kind of substance, though two of them indeed
+  are commonly accounted Vegetable (which, whether they be so or no, I
+  shall not now dispute) But this seems common to all three, that they
+  undergo a tanning or dressing, whereby the interspers'd juices are wasted
+  and wash'd away before the texture of them can be discover'd.</p>
+
+  <p>What their way is of dressing, or curing Sponges, I confess, I cannot
+  learn; but the way of dressing <i>Spunk</i>, is, by boiling it a good
+  while in a strong <i>Lixivium</i>, and then beating it very well; and the
+  manner of dressing Leather is sufficiently known.</p>
+
+  <p>It were indeed extremely desirable, if such a way could be found
+  whereby the <i>Parenchyma</i> or flesh of the Muscles, and several other
+  parts of the body, might be wash'd, or wafted clean away, without
+  vitiating the form of the <i>fibrous</i> parts or vessells of it, for
+  hereby the texture of thole parts, by the help of a good
+  <i>Microscope</i>, might be most accurately found.</p>
+
+  <p>But to digress no further, we may, from this discovery of the
+  <i>Microscope</i>, plainly enough understand how the skin, though it
+  looks so close as it does, comes to give a passage to so vast a quantity
+  of <i>excrementitious</i> substances, as the diligent <i>Sanctorius</i>
+  has excellently observed it to do, in his <i>medicina statica</i>; for it
+  seems very probable, from the texture after dressing, that there are an
+  infinit of pores that every way pierce it, and that those pores are onely
+  fill'd with some kind of juice, or some very pulpy soft substance, and
+  thereby the steams may almost as easily find a passage through such a
+  fluid <i>vehicle</i> as the vaporous bubbles which are generated at the
+  bottom of a Kettle of hot water do find a passage through that fluid
+  <i>medium</i> into the ambient Air.</p>
+
+  <p>Nor is the skin of animals only thus pervious, but even those of
+  vegetables also seem to be the same; for otherwise I cannot conceive why,
+  if two sprigs of Rosemary (for Instance) be taken as exactly alike in all
+  particulars as can be, and the one be set with the bottom in a Glass of
+  water, and the other be set just without the Glass, but in the Air onely,
+  though you stop the lower end of that in the Air very carefully with Wax,
+  yet shall it presently almost wither, whereas the other that seems to
+  have a supply from the subjacent water by its small pipes, or
+  <i>microscopical</i> pores, preserves its greenness for many days, and
+  sometimes weeks.</p>
+
+  <p>Now, this to me, seems not likely to proceed from any other cause then
+  the <i>avolation</i> of the juice through the skin; for by the Wax, all
+  those other pores of the stem are very firmly and closely stop'd up. And
+  from the more or less porousness of the skins or rinds of Vegetables may,
+  perhaps, be somewhat of the reason given, why they keep longer green, or
+  sooner wither; for we may observe by the bladdering and craking of the
+  leaves of Bays, Holly, Laurel, <i>&amp;c.</i> that their skins are very
+  close, and do not suffer so free a passage through them of the included
+  juices.</p>
+
+  <p>But of this, and of the Experiment of the Rosemary, I shall elsewhere
+  more fully consider, seeming to me an extreme luciferous Experiment, such
+  as seems indeed very plainly to prove the <i>Schematism</i> or structure
+  of Vegetables altogether <i>mechanical</i>,
+  and as necessary, that (water and warmth being apply'd to the bottom of
+  the sprig of a Plant) some of it should be carried upwards into the stem,
+  and thence distributed into the leaves, as that the water of the
+  <i>Thames</i> covering the bottom of the Mills at the Bridge foot of
+  <i>London</i>, and by the ebbing and flowing of it, passing strongly by
+  them, should have some part of it convey'd to the Cesterns above, and
+  thence into several houses and Cesterns up and down the City.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXIII" id="obsXXXIII">XXXIII</a>. <i>Of the </i>Scales<i> of a </i>Soal<i>, and other Fishes.</i></h3>
+
+  <p>Having hinted somewhat of the skin and covering of terrestrial
+  Animals, I shall next add an Observation I made on the skin and Scales of
+  a <i>Soal</i>, a small Fish, commonly enough known; and here in Fishes,
+  as well as other Animals, Nature follows its usual method, framing all
+  parts so, as that they are both usefull and ornamental in all its
+  composures, mingling <i>utile</i> and <i>dulce</i> together; and both
+  these designs it seems to follow, though our unassisted senses are not
+  able to peceive them: This is not onely manifest in the covering of this
+  Fish, but in multitudes of others, which it would be too long to
+  enumerate, witness particularly that small Sand Shell, which I mention'd
+  in the XI. Observation, and infinite other small Shells and Scales,
+  divers of which I have view'd. This skin I view'd, was flead from a
+  pretty large <i>Soal</i>, and then expanded and dry'd, the inside of it,
+  when dry, to the naked eye, look'd very like a piece of Canvass, but the
+  <i>Microscope</i> discover'd that texture to be nothing else, but the
+<span class="sidenote">
+<a href="images/scheme-21.png" target="_blank"><i>Schem.</i> 21.</a><br /><i>Fig.</i> 2.
+</span>
+  inner ends of those curious Scolop'd Scales I, I, I, in the second
+  <i>Figure</i> of the XXI. <i>Scheme</i>, namely, the part of GGGG (of the
+  larger representation of a single Scale, in the first <i>Figure</i> of
+  the same <i>Scheme</i>) which on the back side, through an ordinary
+  single Magnifying Glass, look'd not unlike the Tyles on an house.</p>
+
+  <p>The outside of it, to the naked eye, exhibited nothing more of
+  ornament, save the usual order of ranging the Scales into a
+  <i>triagonal</i> form, onely the edges seem'd a little to shine, the
+  finger being rubb'd from the tail-wards towards the head, the Scales
+  seem'd to stay and raze it; But through an ordinary Magnifying glass, it
+  exhibited a most curiously carved and adorned surface, such as is visible
+  in the second <i>Figure</i>, each of those (formerly almost
+  imperceptible) Scales appearing much of the shape I, I, I, that is, they
+  were round, and protuberant, and somewhat shap'd like a Scolop, the whole
+  Scale being creas'd with curiously wav'd and indented ridges, with
+  proportionable furrows between; each of which was terminated with a very
+  sharp transparent bony substance, which, like so many small Turnpikes,
+  seem'd to arm the edges.</p>
+
+  <p>The back part KKK was the skin into which each of these Scales were
+  very deeply fix'd, in the curious regular order, visible in the second
+  <i>Figure</i>. The length and shape of the
+  part of the Scale which was buried by the skin, is evidenced by the first
+  <i>Figure</i>; which is the representation of one of them pluck'd out and
+  view'd through a good <i>Microscope</i>, namely, the part LFGGFL, wherein
+  is also more plainly to be seen, the manner of carving of the scolopt
+  part of every particular Scale, how each ridge or barr EEE is alternately
+  hollowed or engraven, and how every gutter between them is terminated
+  with very transparent and hard pointed spikes, and how every other of
+  these, as AAAA, are much longer then the interjacent ones, DDD.</p>
+
+  <p>The texture or form also of the hidden part appears, namely, the
+  middle part, GGG, seems to consist of a great number of small quills or
+  pipes, by which, perhaps, the whole may be nourished; and the side parts
+  FF consist of a more fibrous texture, though indeed the whole Scale
+  seem'd to be of a very tough gristly substance like the larger Scales of
+  other Fishes.</p>
+
+  <p>The Scales of the skin of a Dog-fish (which is us'd by such as work in
+  Wood, for the smoothing of their work, and consists plainly enough to the
+  naked eye, of a great number off small horny points) through the
+  <i>Microscope</i> appear'd each of them curiously ridg'd, and very neatly
+  carved; and indeed, you can hardly look on the scales of any Fish, but
+  you may discover abundance of curiosity and beautifying; and not only in
+  these Fishes, but in the shells and crusts or armour of most sorts of
+  <i>Marine</i> Animals so invested.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXIV" id="obsXXXIV">XXXIV</a>. <i>Of the Sting of a Bee.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-16.png" target="_blank"><i>Schem.</i> 16.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>The Sting of a <i>Bee</i>, delineated in the second Figure of the XVI.
+  <i>Scheme</i>, seems to be a weapon of offence, and is as great an
+  Instance, that Nature did realy intend revenge as any, and that first,
+  because there seems to be no other use of it. Secondly, by reason of its
+  admirable shape, seeming to be purposely shap'd for that very end.
+  Thirdly, from the virulency of the liquor it ejects, and the sad effects
+  and symptoms that follow it.</p>
+
+  <p>But whatever be the use of it, certain it is, that the structure of it
+  is very admirable; what it appears to the naked eye, I need not describe,
+  the thing being known almost to every one, but it appears through the
+  <i>Microscope</i>, to consist of two parts, the one a sheath, without a
+  chape or top, shap'd almost like the Holster of a Pistol, beginning at
+  <i>d</i>, and ending at <i>b</i>, this sheath I could most plainly
+  perceive to be hollow, and to contain in it, both a Sword or Dart, and
+  the poisonous liquor that causes the pain. The sheath or case seem'd to
+  have several joints or settings together, marked by <i>fghiklmno</i>, it
+  was arm'd moreover neer the top, with several crooks or forks
+  (<i>pqrst</i>) on one side, and (<i>pqrstu</i>) on the other, each of
+  which seem'd like so many Thorns growing on a briar, or rather like so
+  many Cat's Claws; for the crooks themselves seem'd to be little sharp
+  transparent points or claws, growing out of little <i>protuberancies</i>
+  on the side of the sheath, which, by observing
+  the Figure diligently, is easie enough to be perceiv'd; and from several
+  particulars, I suppose the Animal has a power of displaying them, and
+  shutting them in again as it pleases, as a Cat does its claws, or as an
+  Adder or Viper can its teeth or fangs.</p>
+
+  <p>The other part of the Sting was the Sword, as I may so call it, which
+  is sheath'd, as it were, in it, the top of which <i>ab</i> appears quite
+  through at the smaller end, just as if the chape of the sheath of a Sword
+  were lost, and the end of it appear'd beyond the Scabbard; the end of
+  this Dart(<i>a</i>) was very sharp, and it was arm'd likewise with the
+  like Tenterhooks or claws with those of the sheath, such as (<i>vxy</i>,
+  <i>xyzz</i>) these crooks, I am very apt to think, can be clos'd up also,
+  or laid flat to the sides of the Sword when it is drawn into the
+  Scabbard, as I have several times observ'd it to be, and can be spred
+  again or extended when ever the Animal pleases.</p>
+
+  <p>The consideration of which very pretty structure, has hinted to me,
+  that certainly the use of these claws seems to be very considerable, as
+  to the main end of this Instrument, for the drawing in, and holding the
+  sting in the flesh; for the point being very sharp, the top of the Sting
+  or Dagger (<i>ab</i>) is very easily thrust into an Animal's body, which
+  being once entred, the Bee, by endeavouring to pull it into the sheath,
+  draws (by reason of the crooks (<i>vxy</i>) and (<i>xyzz</i>) which lay
+  hold of the skin on either side) the top of the sheath (<i>tsrv</i>) into
+  the skin after it, and the crooks <i>t</i>, <i>s</i>, and <i>r</i>,
+  <i>v</i>, being entred, when the Bee endeavours to thrust out the top of
+  the sting out of the sheath again, they lay hold of the skin on either
+  side, and do not onely keep the sheath from sliding back, but helps the
+  top inwards, and thus, by an alternate and successive retracting and
+  emitting of the Sting in and out of the sheath, the little enraged
+  creature by degrees makes his revengfull weapon pierce the toughest and
+  thickest Hides of his enemies, in so much that some few of these stout
+  and resolute soldiers with these little engines, do often put to flight a
+  huge masty Bear, one of their deadly enemies, and thereby shew the world
+  how much more considerable in Warr a few skilfull Engineers and resolute
+  soldiers politickly order'd, that know how to manage such engines, are,
+  then a vast unweildy rude force, that confides in, and acts onely by, its
+  strength. But (to proceed) that he thus gets in his Sting into the skin,
+  I conjecture, because, when I have observ'd this creature living, I have
+  found it to move the Sting thus, to and fro, and thereby also, perhaps,
+  does, as 'twere, pump or force out the poisonous liquor, and make it hang
+  at the end of the sheath about <i>b</i> in a drop. The crooks, I suppose
+  also to be the cause why these angry creatures, hastily removing
+  themselves from their revenge, do often leave these weapons behind them,
+  sheath'd, as 'twere, in the flesh, and, by that means, cause the painfull
+  symptoms to be greater, and more lasting, which are very probably caus'd,
+  partly by the piercing and tearing of the skin by the Sting, but chiefly
+  by the corrosive and poisonous liquor that is by this Syringe-pipe
+  convey'd among the sensitive parts thereof and thereby more easily gnaws
+  and corrodes those tender <i>fibres</i>: As
+  I have shewed in the description of a Nettle and of Cowhage.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXV" id="obsXXXV">XXXV</a>. <i>Of the contexture and shape of the particles of
+</i>Feathers<i>.</i></h3>
+
+  <p>Examining several sorts of <i>Feathers</i>, I took notice of these
+  particulars in all sorts of wing-Feathers, especially in those which
+  serv'd for the beating of the air in the action of flying.</p>
+
+  <p>That the outward surface of the Quill and Stem was of a very hard,
+  stiff, and horny substance, which is obvious enough, and that the part
+  above the Quill was fill'd with a very white and light pith, and, with
+  the <i>Microscope</i>, I found this pith to be nothing else, but a kind
+  of natural <i>congeries</i> of small bubbles, the films of which seem to
+  be of the same substance with that of the Quill, that is, of a stiff
+  transparent horny substance.</p>
+
+  <p>Which particular seems to me, very worthy a more serious
+  consideration; For here we may observe Nature, as 'twere, put to its
+  shifts, to make a substance, which shall be both light enough, and very
+  stiff and strong, without varying from its own establish'd principles,
+  which we may observe to be such, that very strong bodies are for the most
+  part very heavie also, a strength of the parts usually requiring a
+  density, and a density a gravity; and therefore should Nature have made a
+  body so broad and so strong as a Feather, almost, any other way then what
+  it has taken, the gravity of it must necessarily have many times exceeded
+  this; for this pith seems to be like so many stops or cross pieces in a
+  long optical tube, which do very much contribute to the strength of the
+  whole, the pores of which were such, as that they seem'd not to have any
+  communication with one another, as I have elsewhere hinted.</p>
+
+  <p>But the Mechanism of Nature is usually so excellent, that one and the
+  same substance is adapted to serve for many ends. For the chief use of
+  this, indeed, seems to be for the supply of nourishment to the downy or
+  feathery part of the stem; for 'tis obvious enough in all sorts of
+  Feathers, that 'tis plac'd just under the roots of the branches that grow
+  out of either side of the quill or stalk, and is exactly shap'd according
+  to the ranking of those branches, coming no lower into the quill, then
+  just the beginning of the downy branches, and growing onely on the under
+  side of of the quill where those branches do so. Now, in a ripe Feather
+  (as one may call it) it seems difficult to conceive how the <i>Succus
+  nutritius</i> should be convey'd to this pith; for it cannot, I think, be
+  well imagin'd to pass through the substance of the quill, since, having
+  examin'd it with the greatest diligence I was able, I could not find the
+  least appearance of pores; but he that shall well examine an unripe or
+  pinn'd Feather, will plainly enough perceive the Vessel for the
+  conveyance of it to be the thin filmy pith (as 'tis call'd) which passes
+  through the middle of the quill.</p>
+
+  <p>As for the make and contexture of the Down it self, it is indeed very
+  rare and admirable, and such as I can
+  hardly believe, that the like is to be discover'd in any other body in
+  the world; for there is hardly a large Feather in the wing of a Bird, but
+  contains neer a million of distinct parts, and every one of them shap'd
+  in a most regular &amp; admirable form, adapted to a particular Design:
+  For examining a middle ciz'd Goose-quill, I easily enough found with my
+  naked eye, that the main stem of it contain'd about 300. longer and more
+  Downy branchings upon one side, and as many on the other of more stiff
+  but somewhat shorter branchings. Many of these long and downy branchings,
+  examining with an ordinary <i>Microscope</i>, I found divers of them to
+  contain neer 1200. small leaves (as I may call them, such as EF of the
+<span class="sidenote">
+<a href="images/scheme-22.png" target="_blank"><i>Schem.</i> 22.</a><br /><i>Fig.</i> 1.
+</span>
+  first Figure of the 22. <i>Scheme</i>) and as many stalks on the other
+  side, such as IK of the same Figure, each of the leaves or branchings,
+  EF, seem'd to be divided into about sixteen or eighteen small joints, as
+  may be seen plainly enough in the Figure, out of most of which there seem
+  to grow small long <i>fibres</i>, such as are express'd in the Figure,
+  each of them very proportionably shap'd according to its position, or
+  place on the stalk EF; those on the under side of it, namely, 1, 2, 3, 4,
+  5, 6, 7, 8, 9, <i>&amp;c.</i> being much longer then those directly
+  opposite to them on the upper; and divers of them, such as 2, 3, 4, 5, 6,
+  7, 8, 9, <i>&amp;c.</i> were terminated with small crooks, much
+  resembling those small crooks, which are visible enough to the naked eye,
+  in the seed-buttons of Bur-docks. The stalks likewise, IK on the other
+  side, seem'd divided into neer as many small knotted joints, but without
+  any appearance of strings or crooks, each of them about the middle K,
+  seem'd divided into two parts by a kind of fork, one side of which,
+  namely, KL, was extended neer the length of KI, the other, M, was very
+  short.</p>
+
+  <p>The transverse Sections of the stems of these branchings, manifested
+  the shape or figure of it to be much like INOE, which consisted of a
+  horny skin or covering, and a white seemingly frothy pith, much like the
+  make of the main stem of a Feather.</p>
+
+  <p>The use of this strange kind of form, is indeed more admirable then
+  all the rest, and such as deserves to be much more seriously examin'd and
+  consider'd, then I have hitherto found time or ability to do; for
+  certainly, it may very much instruct us in the nature of the Air,
+  especially as to some properties of it.</p>
+
+  <p>The stems of the Downy branches INOE, being rang'd in the order
+  visible enough to the naked eye, at the distance of IF, or somewhat more,
+  the <i>collateral</i> stalks and leaves (if I may so call those bodies I
+  newly described) are so rang'd, that the leaves or hairy stalks of the
+  one side lie at top, or are incumbent on the stalks of the other, and
+<span class="sidenote">
+<a href="images/scheme-22.png" target="_blank"><i>Schem.</i> 22.</a><br /><i>Fig.</i> 2.
+</span>
+  cross each other, much after the manner express'd in the second Figure of
+  the 22. <i>Scheme</i>, by which means every of those little hooked
+  <i>fibres</i> of the leaved stalk get between the naked stalks, and the
+  stalks being full of knots, and a prety way dis-join'd, so as that the
+  <i>fibres</i> can easily get between them, the two parts are so closely
+  and admirably woven together, that it is able to impede, for the greatest
+  part, the transcursion of the Air; and though they are so exceeding
+  small, as that the thickness of one of these
+  stalks amounts not to a 500. part of an Inch, yet do they compose so
+  strong a texture, as, notwithstanding the exceeding quick and violent
+  beating of them against the Air, by the strength of the Birds wing, they
+  firmly hold together. And it argues an admirable providence of Nature in
+  the contrivance and fabrick of them; for their texture is such, that
+  though by any external injury the parts of them are violently dis-joyn'd,
+  so as that the leaves and stalks touch not one another, and consequently
+  several of these rents would impede the Bird's flying; yet, for the most
+  part, of themselves they readily re-join and re-contex themselves, and
+  are easily by the Birds stroking the Feather, or drawing it through its
+  Bill, all of them settled and woven into their former and natural
+  posture; for there are such an infinite company of those small
+  <i>fibres</i> in the under side of the leaves, and most of them have such
+  little crooks at their ends, that they readily catch and hold the stalks
+  they touch.</p>
+
+  <p>From which strange contexture, it seems rational to suppose that there
+  is a certain kind of mesh or hole so small, that the Air will not very
+  easily pass through it, as I hinted also in the sixth Observation about
+  small Glass Canes, for otherwise it seems probable, that Nature would
+  have drawn over some kind of thin film which should have covered all
+  those almost square meshes or holes, there seeming through the
+  <i>Microscope</i> to be more then half of the surface of the Feather
+  which is open and visibly pervious; which conjecture will yet seem more
+  probable from the texture of the brushie wings of the <i>Tinea
+  argentea</i>, or white Feather wing'd moth, which I shall anone describe.
+  But Nature, that knows best its own laws, and the several properties of
+  bodies, knows also best how to adapt and fit them to her designed ends,
+  and whoso would know those properties, must endeavour to trace Nature in
+  its working, and to see what course she observes. And this I suppose will
+  be no inconsiderable advantage which the <i>Schematisms</i> and
+  Structures of Animate bodies will afford the diligent enquirer, namely,
+  most sure and excellent instructions, both as to the practical part of
+  <i>Mechanicks</i> and to the <i>Theory</i> and knowledge of the nature of
+  the bodies and motions.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXVI" id="obsXXXVI">XXXVI</a>. <i>Of </i>Peacoks<i>, </i>Ducks<i>, and other </i>Feathers<i> of
+  changeable colours.</i></h3>
+
+  <p>The parts of the Feathers of this glorious Bird appear, through the
+  <i>Microscope</i>, no less gaudy then do the whole Feathers; for, as to
+  the naked eye 'tis evident that the stem or quill of each Feather in the
+  tail sends out multitudes of <i>Lateral</i> branches, such as AB in the
+<span class="sidenote">
+<a href="images/scheme-22.png" target="_blank"><i>Schem.</i> 22.</a><br /><i>Fig.</i> 3.
+</span>
+  third Figure of the 22. <i>Scheme</i> represents a small part of about
+  1/32 part of an Inch long, and each of the <i>lateral</i> branches emit
+  multitudes of little sprigs, threads or hairs on either side of them,
+  such as CD, CD, CD, so each of those threads in the <i>Microscope</i>
+  appears a large long body, consisting of a multitude
+  of bright reflecting parts, whose Figure 'tis no easie matter to
+  determine, as he that examines it shall find; for every new position of
+  it to the light makes it perfectly seem of another form and shape, and
+  nothing what it appear'd a little before; nay, it appear'd very differing
+  ofttimes from so seemingly inconsiderable a circumstance, that the
+  interposing of ones hand between the light and it, makes a very great
+  change, and the opening or shutting a Casement and the like, very much
+  diversifies the appearance. And though, by examining the form of it very
+  many ways, which would be tedious here to enumerate, I suppose I have
+  discover'd the true Figure of it, yet oftentimes, upon looking on it in
+  another posture, I have almost thought my former observations deficient,
+  though indeed, upon further examination, I have found even those also to
+  confirm them.</p>
+
+  <p>These threads therefore I find to be a <i>congeries</i> of small
+  <i>Laminæ</i> or plates, as <i>eeeee</i>, &amp;c. each of them shap'd
+  much like this of <i>abcd</i>, in the fourth <i>Figure</i>, the part
+  <i>ac</i> being a ridge, prominency, or stem, and <i>b</i> and <i>d</i>
+  the corners of two small thin Plates that grow unto the small stalk in
+  the middle, so that they make a kind of little feather; each of these
+  Plates lie one close to another, almost like a company of sloping ridge
+  or gutter Tyles; they grow on each side of the stalk opposite to one
+  another, by two and two, from top to bottom, in the manner express'd in
+  the fifth Figure, the tops of the lower covering the roots of the next
+  above them; the under side of each of these laminated bodies, is of a
+  very dark and opacous substance, and suffers very few Rays to be
+  trajected, but reflects them all toward that side from whence they come,
+  much like the foil of a Looking-glass; but their upper sides seem to me
+  to consist of a multitude of thin plated bodies, which are exceeding
+  thin, and lie very close together, and thereby, like mother of Pearl
+  shells, do not onely reflect a very brisk light, but tinge that light in
+  a most curious manner; and by means of various positions, in respect of
+  the light, they reflect back now one colour, and then another, and those
+  most vividly.</p>
+
+  <p>Now, that these colours are onely <i>fantastical</i> ones, that is,
+  such as arise immediately from the refractions of the light, I found by
+  this, that water wetting these colour'd parts, destroy'd their colours,
+  which seem'd to proceed from the alteration of the reflection and
+  refraction. Now, though I was not able to see those hairs at all
+  transparent by a common light, yet by looking on them against the Sun, I
+  found them to be ting'd with a darkish red colour, nothing a-kin to the
+  curious and lovely greens and blues they exhibited.</p>
+
+  <p>What the reason of colour seems to be in such thin plated bodies, I
+  have elsewhere shewn. But how water cast upon those threads destroys
+  their colours, I suppose to be perform'd thus; The water falling upon
+  these plated bodies from its having a greater congruity to Feathers then
+  the Air, insinuates it self between those Plates, and so extrudes the
+  strong reflecting Air, whence both these parts grow more transparent, as
+  the <i>Microscope</i> informs, and colourless also, at best retaining a
+  very faint and dull colour. But this wet being wasted away
+  by the continual evaporations and steams that pass through them from the
+  Peacock, whil'st that Bird is yet alive, the colours again appear in
+  their former luster, the <i>interstitia</i> of these Plates being fill'd
+  with the strongly reflecting Air.</p>
+
+  <p>The beauteous and vivid colours of the Feathers of this Bird, being
+  found to proceed from the curious and exceeding smalness and fineness of
+  the reflecting parts, we have here the reason given us of all those
+  gauderies in the apparel of other Birds also, and how they come to exceed
+  the colours of all other kinds of Animals, besides Insects; for since (as
+  we here, and elsewhere also shew) the vividness of a colour, depends upon
+  the fineness and transparency of the reflecting and refracting parts; and
+  since our <i>Microscope</i> discovers to us, that the component parts of
+  feathers are such, and that the hairs of Animals are otherwise; and since
+  we find also by the Experiment of that Noble and most Excellent Person I
+  formerly named; that the difference between Silk and Flax, as to its
+  colour, is nothing else (for Flax reduc'd to a very great fineness of
+  parts, both white and colour'd, appears as white and as vivid as any
+  Silk, but loses that brightness and its Silken aspect as soon as it is
+  twisted into thread, by reason that the component parts, though very
+  small and fine, are yet pliable flakes, and not cylinders, and thence, by
+  twisting, become united into one opacous body, whereas the threads of
+  Silk and Feathers retain their lustre, by preserving their cylindrical
+  form intire without mixing; so that each reflected and refracted beam
+  that composes the gloss of Silk, preserves its own property of modulating
+  the light intire); And since we find the same confirm'd by many other
+  Experiments elsewhere mentioned, I think we may safely conclude this for
+  an Axiome, that wheresoever we meet with transparent bodies, spun out
+  into very fine parts, either cleer, or any ways ting'd, the colours
+  resulting from such a <i>composition</i> must necessarily be very
+  glorious, vivid, and cleer, like those of Silk and Feathers. This may
+  perhaps hint some usefull way of making other bodies, besides Silk, be
+  susceptible of bright tinctures, but of this onely by the by.</p>
+
+  <p>The changeable colour'd Feathers also of Ducks, and several other
+  Birds, I have found by examination with my <i>Microscope</i>, to proceed
+  from much the same causes and textures.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXVII" id="obsXXXVII">XXXVII</a>. <i>Of the Feet of </i>Flies<i>, and several other </i>Insects<i>.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-23.png" target="_blank"><i>Schem.</i> 23.</a><br /><i>Fig.</i> 1, 2.
+</span>
+  <p>The foot of a Fly (delineated in the first <i>Figure</i> of the 23.
+  <i>Scheme</i>, which represents three joints, the two Tallons, and the
+  two Pattens in a flat posture; and in the second <i>Figure</i> of the
+  same <i>Scheme</i>, which represents onely one joint, the Tallons and
+  Pattens in another posture) is of a most admirable and curious
+  contrivance, for by this the Flies are inabled to walk against the sides
+  of Glass, perpendicularly upwards, and to contain
+  themselves in that posture as long as they please; nay, to walk and
+  suspend themselves against the under surface of many bodies, as the
+  ceiling of a room, or the like, and this with as great a seeming facility
+  and firmness, as if they were a kind of <i>Antipodes</i>, and had a
+  <i>tendency</i> upwards, as we are sure they have the contrary, which
+  they also evidently discover, in that they cannot make themselves so
+  light, as to stick or suspend themselves on the under surface of a Glass
+  well polish'd and cleans'd; their suspension therefore is wholly to be
+  ascrib'd to some Mechanical contrivance in their feet; which, what it is,
+  we shall in brief explain, by shewing, that its Mechanism consists
+  principally in two parts, that is, first its two Claws, or Tallons, and
+  secondly, two Palms, Pattens, or Soles.</p>
+
+  <p>The two Tallons are very large, in proportion to the foot, and
+  handsomly shap'd in the manner describ'd in the <i>Figures</i>, by AB,
+  and AC, the bigger part of them from A to <i>dd</i>, is all hairy, or
+  brisled, but toward the top, at C and B smooth, the tops or points, which
+  seem very sharp turning downwards and inwards, are each of them mov'd on
+  a joint at A, by which the Fly is able to open or shut them at pleasure,
+  so that the points B and C being entered in any pores, and the Fly
+  endeavouring to shut them, the Claws not onely draw one against another,
+  and so fasten each other, but they draw the whole foot, GGADD forward, so
+  that on a soft footing, the tenters or points GGGG, (whereof a Fly has
+  about ten in each foot, to wit, two in every joint) run into the pores,
+  if they find any, or at least make their way; and this is sensible to the
+  naked eye, in the feet of a <i>Chafer</i>, which, if he be suffer'd to
+  creep over the hand, or any other part of the skin of ones body, does
+  make his steps as sensible to the touch as the sight.</p>
+
+  <p>But this contrivance, as it often fails the <i>Chafer</i>, when he
+  walks on hard and close bodies, so would it also our Fly, though he be a
+  much lesser, and nimbler creature, and therefore Nature has furnish'd his
+  foot with another <i>additament</i> much more curious and admirable, and
+  that is, with a couple of Palms, Pattens or Soles DD, the structure of
+  which is this:</p>
+
+  <p>From the bottom or under part of the last joint of his foot, K, arise
+  two small thin plated horny substances, each consisting of two flat
+  pieces, DD, which seem to be flexible, like the covers of a Book, about
+  FF, by which means, the plains of the two sides EE, do not always lie in
+  the same plain, but may be sometimes shut closer, and so each of them may
+  take a little hold themselves on a body; but that is not all, for the
+  under sides of these Soles are all beset with small brisles, or tenters,
+  like the Wire teeth of a Card used for working Wool, the points of all
+  which tend forwards, hence the two Tallons drawing the feet forwards, as
+  I before hinted, and these being applied to the surface of the body with
+  all the points looking the contrary way, that is, forwards and outwards,
+  if there be any irregularity or yielding in the surface of the body, the
+  Fly suspends it self very firmly and easily, without the access or need
+  of any such Sponges fill'd with an imaginary <i>gluten</i>, as many have,
+  for want of good Glasses, perhaps, or a troublesome and diligent
+  examination, suppos'd.</p>
+
+  <p>Now, that the Fly is able to walk on Glass, proceeds partly from some
+  ruggedness of the surface: and chiefly from
+  a kind of tarnish, or dirty smoaky substance, which adheres to the
+  surface of that very hard body; and though the pointed parts cannot
+  penetrate the substance of Glass, yet may they find pores enough in the
+  tarnish, or at least make them.</p>
+
+  <p>This Structure I somewhat the more diligently survey'd, because I
+  could not well comprehend, how, if there were such a glutinous matter in
+  those supposed Sponges, as most (that have observ'd that Object in a
+  <i>Microscope</i>) have hitherto believ'd, how, I say, the Fly could so
+  readily unglew and loosen its feet: and, because I have not found any
+  other creature to have a contrivance any ways like it, and chiefly, that
+  we might not be cast upon unintelligible explications of the
+  <i>Phænomena</i> of Nature, at least others then the true ones, where our
+  senses were able to furnish us with an intelligible, rationall and true
+  one.</p>
+
+  <p>Somewhat a like contrivance to this of Flies shall we find in most
+  other Animals, such as all kinds of Flies and case-wing'd creatures; nay,
+  in a Flea, an Animal abundantly smaller then this Fly. Other creatures,
+  as Mites, the Land-Crab, <i>&amp;c.</i> have onely one small very sharp
+  Tallon at the end of each of their legs, which all drawing towards the
+  center or middle of their body, inable these exceeding light bodies to
+  suspend and fasten themselves to almost any surface.</p>
+
+  <p>Which how they are able to do, will not seem strange, if we consider,
+  first, how little body there is in one of these creatures compar'd to
+  their superficies, or outside, their thickness, perhaps, oftentimes, not
+  amounting to the hundredth part of an Inch: Next, the strength and
+  agility of these creatures compar'd to their bulk, being, proportionable
+  to their bulk, perhaps, an hundred times stronger then an Horse or Man.
+  And thirdly, if we consider that Nature does always appropriate the
+  instruments, so as they are the most fit and convenient to perform their
+  offices, and the most simple and plain that possibly can be; this we may
+  see further verify'd also in the foot of a Louse which is very much
+  differing from those I have been describing, but more convenient and
+  necessary for the place of its habitation, each of his leggs being footed
+  with a couple of small claws which he can open or shut at pleasure,
+  shap'd almost like the claws of a Lobster or Crab, but with appropriated
+  contrivances for his peculiar life, which being to move its body to and
+  fro upon the hairs of the creature it inhabits, Nature has furnish'd one
+  of its claws with joints, almost like the joints of a man's fingers, so
+  as thereby it is able to encompass or grasp a hair as firmly as a man can
+  a stick or rope.</p>
+
+  <p>Nor, is there a less admirable and wonderfull <i>Mechanism</i> in the
+  foot of a Spider, whereby he is able to spin, weave, and climb, or run on
+  his curious transparent clew, of which I shall say more in the
+  description of that Animal.</p>
+
+  <p>And to conclude, we shall in all things find, that Nature does not
+  onely work Mechanically, but by such excellent and most compendious, as
+  well as stupendious contrivances, that it were impossible for all the
+  reason in the world to find out any contrivance to do the same thing that
+  should have more convenient properties. And can any be so sottish,
+  as to think all those things the
+  productions of chance? Certainly, either their Ratiocination must be
+  extremely depraved, or they did never attentively consider and
+  contemplate the Works of the Al-mighty.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXVIII" id="obsXXXVIII">XXXVIII</a>. <i>Of the Structure and motion of the Wings
+of </i>Flies<i>.</i></h3>
+
+  <p>The Wings of all kinds of Insects, are, for the most part, very
+  beautifull Objects, and afford no less pleasing an Object to the mind to
+  speculate upon, then to the eye to behold. This of the blue Fly, among
+  the rest, wants not its peculiar ornaments and contrivances; it grows out
+  of the <i>Thorax</i>, or middle part of the body of a Fly, and is seated
+  a little beyond the center of gravity in the body towards the head, but
+  that <i>Excentricly</i> is curiously balanc'd; first, by the expanded
+  <i>Area</i> of the wings which lies all more backwards then the root, by
+  the motion of them, whereby the center of their vibration is much more
+  backwards towards the tail of the Fly then the root of the wing is. What
+  the vibrative motion of the wings is, and after what manner they are
+  moved, I have endeavoured by many trials to find out: And first for the
+  manner of their motion, I endeavoured to observe several of those kind of
+  small Spinning Flies, which will naturally suspend themselves, as it
+  were, pois'd and steady in one place of the air, without rising or
+  falling, or moving forwards or backwards; for by looking down on those, I
+  could by a kind of faint shadow, perceive the utmost extremes of the
+  vibrative motion of their wings, which shadow, whil'st they so
+  endeavoured to suspend themselves, was not very long, but when they
+  endeavour'd to flie forwards, it was somewhat longer; next, I tried it,
+  by fixing the leggs of a Fly upon the top of the stalk of a feather, with
+  Glew, Wax, <i>&amp;c.</i> and then making it endeavour to flie away; for
+  being thereby able to view it in any posture, I collected that the motion
+  of the wing was after this manner. The extreme limits of the vibrations
+  were usually somewhat about the length of the body distant from one
+  another, oftentimes shorter, and sometimes also longer; that the formost
+  limit was usually a little above the back, and the hinder somwhat beneath
+  the belly; between which two limits, if one may ghess by the sound, the
+  wing seem'd to be mov'd forwards and backwards with an equal velocity:
+  And if one may (from the shadow or faint representation the wings
+  afforded, and from the consideration of the nature of the thing) ghess at
+  the posture or manner of the wings moving between them, it seem'd to be
+  this: The wing being suppos'd placed in the upmost limit, seems to be put
+  so that the plain of it lies almost <i>horizontal</i>, but onely the
+  forepart does dip a little, or is somewhat more deprest; in this position
+  is the wing vibrated or mov'd to the lower limit, being almost arrived at
+  the lower limit, the hinder part of the wing moving somewhat faster then
+  the former, the <i>Area</i>, of the wing begins
+  to dip behind, and in that posture seems it to be mov'd to the upper
+  limit back again, and thence back again in the first posture, the former
+  part of the <i>Area</i> dipping again, as it is moved downwards by means
+  of the quicker motion of the main stem which terminates or edges the
+  forepart of the wing. And these vibrations or motions to and fro between
+  the two limits seem so swift, that 'tis very probable (from the sound it
+  affords, if it be compar'd with the vibration of a musical string, tun'd
+  unison to it) it makes many hundreds, if not some thousands of vibrations
+  in a second minute of time. And, if we may be allow'd to ghess by the
+  sound, the wing of a Bee is yet more swift, for the tone is much more
+  acute, and that, in all likelihood, proceeds from the exceeding swift
+  beating of the air by the small wing. And it seems the more likely too,
+  because the wing of a Bee is less in proportion to its body, then the
+  other wing to the body of a Fly; so that for ought I know, it may be one
+  of the quickest vibrating <i>spontaneous</i> motions of any in the world;
+  and though perhaps there may be many Flies in other places that afford a
+  yet more shrill note with their wings, yet 'tis most probable that the
+  quickest vibrating <i>spontaneous</i> motion is to be found in the wing
+  of some creature. Now, if we consider the exceeding quickness of these
+  Animal spirits that must cause these motions, we cannot chuse but admire
+  the exceeding vividness of the governing faculty or <i>Anima</i> of the
+  Insect, which is able to dispose and regulate so the the motive
+  faculties, as to cause every peculiar organ, not onely to move or act so
+  quick, but to do it also so regularly.</p>
+
+  <p>Whil'st I was examining and considering the curious <i>Mechanism</i>
+  of the wings, I observ'd that under the wings of most kind of Flies,
+  Bees, <i>&amp;c.</i> there were plac'd certain <i>pendulums</i> or
+  extended drops (as I may so call them from their resembling motion and
+  figure) for they much resembled a long hanging drop of some transparent
+  viscous liquor; and I observed them constantly to move just before the
+  wings of the Fly began to move, so that at the first sight I could not
+  but ghess, that there was some excellent use, as to the regulation of the
+  motion of the wing, and did phancy, that it might be something like the
+  handle of a Cock, which by vibrating to and fro, might, as 'twere, open
+  and shut the Cock, and thereby give a passage to the determinate
+  influences into the Muscles; afterwards, upon some other trials, I
+  suppos'd that they might be for some use in respiration, which for many
+  reasons I suppose those Animals to use, and, me thought, it was not very
+  improbable, but that they might have convenient passages under the wings
+  for the emitting, at least, of the air, if not admitting, as in the gills
+  of Fishes is most evident; or, perhaps, this <i>Pendulum</i> might be
+  somewhat like the staff to a Pump, whereby these creatures might exercise
+  their <i>Analogous</i> lungs, and not only draw in, but force out, the
+  air they live by: but these were but conjectures, and upon further
+  examination seem'd less probable.</p>
+
+<span class="sidenote">
+<a href="images/scheme-23.png" target="_blank"><i>Schem.</i> 23.</a><br /><i>Fig.</i> 4.<br />
+<a href="images/scheme-26.png" target="_blank"><i>Schem.</i> 26.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>The fabrick of the wing, as it appears through a moderately magnifying
+  <i>Microscope</i>, seems to be a body consisting of two parts, as is
+  visible in the 4. <i>Figure</i> of the 23. <i>Scheme</i>; and by the 2.
+  <i>Figure</i> of the 26. <i>Scheme</i>; the one is a quilly
+  or finny substance, consisting of several long, slender and variously
+  bended quills or wires, something resembling the veins of leaves; these
+  are, as 'twere, the finns or quills which stiffen the whole <i>Area</i>,
+  and keep the other part distended, which is a very thin transparent skin
+  or membrane variously folded, and platted, but not very regularly, and is
+  besides exceeding thickly bestuck with innumerable small bristles, which
+  are onely perceptible by the bigger magnifying <i>Microscope</i>, and not
+  with that neither, but with a very convenient augmentation of sky-light
+  projected on the Object with a burning Glass, as I have elsewhere shew'd,
+  or by looking through it against the light.</p>
+
+  <p>In steed of these small hairs, in several other Flies, there are
+  infinite of small Feathers, which cover both the under and upper sides of
+  this thin film as in almost all the sorts of Butterflies and Moths: and
+  those small parts are not onely shap'd very much like the feathers of
+  Birds, but like those variegated with all the variety of curious bright
+  and vivid colours imaginable; and those feathers are likewise so
+  admirably and delicately rang'd, as to compose very fine flourishings and
+  ornamental paintings, like <i>Turkie</i> and <i>Persian</i> Carpets, but
+  of far more surpassing beauty, as is evident enough to the naked eye, in
+  the painted wings of Butterflies, but much more through an ordinary
+  <i>Microscope</i>.</p>
+
+  <p>Intermingled likewise with these hairs, may be perceived multitudes of
+  little pits, or black spots, in the exended membrane, which seem to be
+  the root of the hairs that grow on the other side; these two bodies seem
+  dispers'd over the whole surface of the wing.</p>
+
+  <p>The hairs are best perceiv'd, by looking through it against the light,
+  or, by laying the wing upon a very white piece of Paper, in a convenient
+  light, for thereby every little hair most manifestly appears; a
+<span class="sidenote">
+<a href="images/scheme-23.png" target="_blank"><i>Schem.</i> 23.</a><br /><i>Fig.</i> 4.
+</span>
+  <i>Specimen</i> of which you may observe drawn in the fourth
+  <i>Figure</i> of the 23. <i>Scheme</i>, AB, CD, EF whereof represent some
+  parts of the bones or quills of the wing, each of which you may perceive
+  to be cover'd over with a multitude of scales, or bristles, the former
+  AB, is the biggest stem of all the wing, and may be properly enough
+  call'd the cut-air, it being that which terminates and stiffens the
+  formost edge of the wing; the fore-edge of this is arm'd with a multitude
+  of little brisles, or Tenter-hooks, in some standing regular and in
+  order, in others not; all the points of which are directed from the body
+  towards the tip of the wing, nor is this edge onely thus fring'd, but
+  even all the whole edge of the wing is covered with a small fringe,
+  consisting of short and more slender brisles.</p>
+
+  <p>This Subject, had I time, would afford excellent matter for the
+  contemplation of the nature of wings and of flying, but, because I may,
+  perhaps, get a more convenient time to prosecute that speculation, and
+  recollect several Observations that I have made of that particular. I
+  shall at present proceed to</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXXXIX" id="obsXXXIX">XXXIX</a>. <i>Of the Eyes and Head of a </i>Grey drone-Fly<i>,
+and of several other creatures.</i></h3>
+
+  <p>I took a large grey <i>Drone-Fly</i>, that had a large head, but a
+  small and slender body in proportion to it, and cutting off its head, I
+  fix'd it with the forepart or face upwards upon my Object Plate (this I
+  made choice of rather then the head of a great blue Fly, because my
+  enquiry being now about the eyes, I found this Fly to have, first the
+  biggest clusters of eyes in proportion to his head, of any small kind of
+  Fly that I have yet seen, it being somewhat inclining towards the make of
+  the large <i>Dragon-Flies</i>. Next, because there is a greater variety
+  in the knobs or balls of each cluster, then is of any small Fly.) Then
+  examining it according to my usual manner, by varying the degrees of
+  light, and altering its position to each kinde of light, I drew that
+<span class="sidenote">
+<a href="images/scheme-24.png" target="_blank"><i>Schem.</i> 24.</a>
+</span>
+  representation of it which is delineated in the 24. <i>Scheme</i>, and
+  found these things to be as plain and evident, as notable and
+  pleasant.</p>
+
+  <p><i>First</i>, that the greatest part of the face, nay, of the head,
+  was nothing else but two large and <i>protuberant</i> bunches, or
+  <i>prominent</i> parts, ABCDEA, the surface of each of which was all
+  cover'd over, or shap'd into a multitude of small <i>Hemispheres</i>,
+  plac'd in a <i>triagonal</i> order, that being the closest and most
+  compacted, and in that order, rang'd over the whole surface of the eye in
+  very lovely rows, between each of which, as is necessary, were left long
+  and regular trenches, the bottoms of every of which, were perfectly
+  intire and not at all perforated or drill'd through, which I most
+  certainly was assured of, by the regularly reflected Image of certain
+  Objects which I mov'd to and fro between the head and the light. And by
+  examining the <i>Cornea</i> or outward skin, after I had stript it off
+  from the several substances that lay within it, and by looking both upon
+  the inside and against the light.</p>
+
+  <p><i>Next</i>, that of those multitudes of <i>Hemispheres</i>, there
+  were observable two degrees of bigness, the half of them that were
+  lowermost, and look'd toward the ground or their own leggs, namely, CDE,
+  CDE being a pretty deal smaller then the other, namely, ABCE, ABCE, that
+  look'd upward, and side-ways, or foreright, and backward, which variety I
+  have not found in any other small Fly.</p>
+
+  <p><i>Thirdly</i>, that every one of these <i>Hemispheres</i>, as they
+  seem'd to be pretty neer the true shape of a <i>Hemisphere</i>, so was
+  the surface exceeding smooth and regular, reflecting as exact, regular,
+  and perfect an Image of any Object from the surface of them, as a small
+  Ball of Quick-silver of that bigness would do, but nothing neer so vivid,
+  the reflection from these being very languid, much like the reflection
+  from the outside of Water, Glass, Crystal, <i>&amp;c.</i> In so much that
+  in each of these <i>Hemispheres</i>, I have been able to discover a
+  Land-scape of those things which lay before my window,
+  one thing of which was a large Tree, whose trunk and top I could plainly
+  discover, as I could also the parts of my window, and my hand and
+  fingers, if I held it between the Window and the Object; a small draught
+  of nineteen of which, as they appear'd in the bigger Magnifying-glass to
+  reflect the Image of the two windows of my Chamber, are delineated in the
+<span class="sidenote">
+<a href="images/scheme-23.png" target="_blank"><i>Schem.</i> 23.</a><br /><i>Fig.</i> 3.
+</span>
+  third <i>Figure</i> of the 23. <i>Scheme</i>.</p>
+
+  <p><i>Fourthly</i>, that these rows were so dispos'd, that there was no
+  quarter visible from his head that there was not some of these
+  <i>Hemispheres</i> directed against, so that a Fly may be truly said to
+  have <i>an eye every way</i>, and to be really <i>circumspect</i>. And it
+  was further observable, that that way where the trunk of his body did
+  hinder his prospect backward, these <i>protuberances</i> were elevated,
+  as it were, above the plain of his shoulders and back, so that he was
+  able to see backwards also over his back.</p>
+
+  <p><i>Fifthly</i>, in living Flies, I have observ'd, that when any small
+  mote or dust, which flies up and down the air, chances to light upon any
+  part of these knobs, as it is sure to stick firmly to it and not fall,
+  though through the <i>Microscope</i> it appears like a large stone or
+  stick (which one would admire, especially since it is no ways probable
+  that there is any wet or glutinous matter upon these <i>Hemispheres</i>,
+  but I hope I shall render the reason in another place) so the Fly
+  presently makes use of his two fore-feet in stead of eye-lids, with
+  which, as with two Brooms or Brushes, they being all bestuck with
+  Brisles, he often sweeps or brushes off what ever hinders the prospect of
+  any of his <i>Hemispheres</i>, and then, to free his leggs from that
+  dirt, he rubs them one against another, the pointed Brisles or Tenters of
+  which looking both one way, the rubbing of them to and fro one against
+  another, does cleanse them in the same manner as I have observ'd those
+  that Card Wool, to cleanse their Cards, by placing their Cards, so as the
+  teeth of both look the same way, and then rubbing them one against
+  another. In the very same manner do they brush and cleanse their bodies
+  and wings, as I shall by and by shew; other creatures have other
+  contrivances for the cleansing and cleering their eyes.</p>
+
+  <p><i>Sixthly</i> that the number of the <i>Pearls</i> or
+  <i>Hemispheres</i> in the clusters of this Fly, was neer 14000. which I
+  judged by numbering certain rows of them several ways, and casting up the
+  whole content, accounting each cluster to contain about seven thousand
+  Pearls, three thousand of which were of a size, and consequently the rows
+  not so thick, and the foure thousand I accounted to be the number of the
+  smaller Pearls next the feet and <i>proboscis</i>. Other Animals I
+  observ'd to have yet a greater number, as the <i>Dragon-Fly</i> or
+  <i>Adderbolt</i>: And others to have a much less company, as an
+  <i>Ant</i>, &amp;c. and several other small Flies and Insects.</p>
+
+  <p><i>Seventhly</i>, that the order of these eies or <i>Hemispheres</i>
+  was altogether curious and admirable, they being plac'd in all kind of
+  Flies, and <i>aerial</i> animals, in a most curious and regular
+  ordination of triangular rows, in which order they are rang'd the neerest
+  together that possibly they can, and consequently leave the least pits or
+  trenches between them. But in <i>Shrimps</i>, <i>Crawfishes</i>,
+  <i>Lobsters</i>, and such kinds of <i>Crustaceous</i> water Animals, I
+  have yet observ'd them rang'd in a quadrangular
+  order, the rows cutting each other at right angles, which as it admits of
+  a less number of Pearls in equal surfaces; so have those creatures a
+  recompence made them, by having their eyes a little movable in their
+  heads, which the other altogether want. So infinitely wise and provident
+  do we find all the Dispensations in Nature, that certainly
+  <i>Epicurus</i>, and his followers, must very little have consider'd
+  them, who ascrib'd those things to the production of chance, that wil, to
+  a more attentive considerer, appear the products of the highest Wisdom
+  and Providence.</p>
+
+  <p>Upon the Anatomy or Dissection of the Head, I observ'd these
+  particulars:</p>
+
+  <p>First, that this outward skin, like the <i>Cornea</i> of the eyes of
+  the greater Animals, was both flexible and transparent, and seem'd,
+  through the <i>Microscope</i> perfectly to resemble the very substance of
+  the <i>Cornea</i> of a man's eye; for having cut out the cluster, and
+  remov'd the dark and <i>mucous</i> stuff that is subjacent to it, I could
+  see it transparent like a thin piece of skin, having as many cavities in
+  the inside of it, and rang'd in the same order as it had
+  <i>protuberances</i> on the outside, and this propriety, I found the same
+  in all the Animals that had it, whether Flies or Shell-Fish.</p>
+
+  <p>Secondly, I found that all Animals that I have observ'd with those
+  kind of eyes; have within this <i>Cornea</i>, a certain cleer liquor or
+  juice, though in a very little quantity, and,</p>
+
+  <p>I observ'd thirdly, that within that cleer liquor, they had a kind of
+  dark <i>mucous</i> lining, which was all spread round within the cavity
+  of the clutter, and seem'd very neer adjoining to it, the colour of
+  which, in some Flies, was grey; in others, black, in others red; in
+  others, of a mix'd colour; in others, spotted; and that the whole
+  clusters, when look'd on whilst the Animal was living, or but newly
+  kill'd, appear'd of the same colour that this coat (as I may so call it)
+  appear'd of, when that outward skin, or <i>Cornea</i>, was remov'd.</p>
+
+  <p>Fourthly, that the rest of the capacity of the clusters was in some,
+  as in Dragon Flies, <i>&amp;c.</i> hollow, or empty; in others fill'd
+  with some kind of substance; in blue Flies, with a reddish musculous
+  substance, with <i>fibres</i> tending from the center or bottom outwards;
+  and divers other, with various and differing kinds of substances.</p>
+
+  <p>That this curious contrivance is the organ of sight to all those
+  various <i>Crustaceous</i> Animals, which are furnish'd with it, I think
+  we need not doubt, if we consider but the several congruities it has with
+  the eyes of greater creatures.</p>
+
+  <p>As first, that it is furnish'd with a <i>Cornea</i>, with a
+  <i>transparent humour</i>, and with a <i>uvea</i> or <i>retina</i>, that
+  the Figure of each of the small <i>Hemispheres</i> are very
+  <i>Spherical</i>, exactly polish'd, and most vivid, lively and plump,
+  when the Animal is living, as in greater Animals, and in like manner
+  dull, flaccid, and irregular, or shrunk, when the Animal is dead.</p>
+
+  <p>Next, that those creatures that are furnish'd with it, have no other
+  organs that have any resemblance to the known eyes of other
+  creatures.</p>
+
+  <p>Thirdly, that those which they call the eyes of Crabs, Lobsters,
+  Shrimps, and the like, and are really so, are <i>Hemispher'd</i>, almost
+  in the same manner as these of Flies are. And that they really are so, I
+  have very often try'd, by cutting off these little movable knobs, and
+  putting the creature again into the water, that it would swim to and fro,
+  and move up and down as well as before, but would often hit it self
+  against the rocks or stones; and though I put my hand just before its
+  head, it would not at all start or fly back till I touch'd it, whereas
+  whil'st those were remaining, it would start back, and avoid my hand or a
+  stick at a good distance before it touch'd it. And if in
+  <i>crustaceous</i> Sea-animals, then it seems very probable also, that
+  these knobs are the eyes in <i>crustaceous</i> Insects, which are also of
+  the same kind, onely in a higher and more active Element; this the
+  conformity or congruity of many other parts common to either of them,
+  will strongly argue, their <i>crustaceous</i> armour, their number of
+  leggs, which are six, beside the two great claws, which answer to the
+  wings in Insects; and in all kind of Spiders, as also in many other
+  Insects that want wings, we shall find the compleat number of them, and
+  not onely the number, but the very shape, figure, joints, and claws of
+  Lobsters and Crabs, as is evident in Scorpions and Spiders, as is visible
+<span class="sidenote">
+<a href="images/scheme-31.png" target="_blank"><i>Schem.</i> 31.</a><br /><i>Fig.</i> 2.<br />
+<a href="images/scheme-33.png" target="_blank"><i>Schem.</i> 33.</a><br /><i>Fig.</i> 2.
+</span>
+  in the second <i>Figure</i> of the 31. <i>Scheme</i>, and in the little
+  Mite-worm, which I call a Land-crab, describ'd in the second Figure of
+  the 33. <i>Scheme</i>, but in their manner of generation being oviparous,
+  <i>&amp;c.</i> And it were very worthy observation, whether there be not
+  some kinds of transformation and metamorphosis in the several states of
+  <i>crustaceous</i> water-animals, as there is in several sorts of
+  Insects; for if such could be met with, the progress of the variations
+  would be much more conspicuous in those larger Animals, then they can be
+  in any kind of Insects our colder Climate affords.</p>
+
+  <p>These being their eyes, it affords us a very pretty Speculation to
+  contemplate their manner of vision, which, as it is very differing from
+  that of <i>biocular</i> Animals, so is it not less admirable.</p>
+
+  <p>That each of these Pearls or <i>Hemispheres</i> is a perfect eye, I
+  think we need not doubt, if we consider onely the outside or figure of
+  any one of them, for they being each of them cover'd with a transparent
+  protuberant <i>Cornea</i>, and containing a liquor within them,
+  resembling the watry or glassie humours of the eye, must necessarily
+  refract all the parallel Rays that fall on them out of the air, into a
+  point not farr distant within them, where (in all probability) the
+  <i>Retina</i> of the eye is placed, and that opacous, dark, and mucous
+  inward coat that (I formerly shew'd) I found to subtend the concave part
+  of the cluster is very likely to be that <i>tunicle</i> or coat, it
+  appearing through the <i>Microscope</i> to be plac'd a little more than a
+  Diameter of those Pearls below or within the <i>tunica cornea</i>. And if
+  so, then is there in all probability, a little Picture or Image of the
+  objects without, painted or made at the bottom of the <i>Retina</i>
+  against every one of those Pearls, so that there are as many impressions
+  on the <i>Retina</i> or opacous skin, as there are Pearls or
+  <i>Hemispheres</i> on the cluster. But because it is impossible for any
+  protuberant surface whatsoever, whether <i>sphærial</i> or other, so to
+  refract the Rays that come from farr remote   <i>lateral</i> points of any Object as to collect them again, and unite
+  them each in a distinct point, and that onely those Rays which come from
+  some point that lies in the <i>Axis</i> of the Figure produc'd, are so
+  accurately refracted to one and the same point again, and that the
+  <i>lateral</i> Rays, the further they are remov'd, the more imperfect is
+  their refracted confluence; It follows therefore, that onely the Picture
+  of those parts of the external objects that lie in, or neer, the
+  <i>Axis</i> of each <i>Hemisphere</i>, are discernably painted or made on
+  the <i>Retina</i> of each <i>Hemisphere</i>, and that therefore each of
+  them can distinctly sensate or see onely those parts which are very neer
+  perpendicularly oppos'd to it, or lie in or neer its optick <i>Axis</i>.
+  Now, though there may be by each of these eye-pearls, a representation to
+  the Animal of a whole <i>Hemisphere</i> in the same manner as in a man's
+  eye there is a picture or sensation in the <i>Retina</i> of all the
+  objects lying almost in an <i>Hemisphere</i>; yet, as in a man's eye
+  also, there are but some very few points which liyng in, or neer, the
+  optick <i>Axis</i> are distinctly discern'd: So there may be multitudes
+  of Pictures made of an Object in the several Pearls, and yet but one, or
+  some very few that are distinct; The representation of any object that is
+  made in any other Pearl, but that which is directly, or very neer
+  directly, oppos'd, being altogether confus'd and unable to produce a
+  distinct vision.</p>
+
+  <p>So that we see, that though it has pleas'd the All-wise Creator, to
+  indue this creature with such multitudes of eyes, yet has he not indued
+  it with the faculty of seeing more then another creature; for whereas
+  this cannot move his head, at least can move it very little, without
+  moving his whole body, <i>biocular</i> creatures can in an instant (or
+  <i>the twinkling of an eye</i>, which, being very quick, is vulgarly used
+  in the same signification) move their eyes so as to direct the optick
+  <i>Axis</i> to any point; nor is it probable, that they are able to see
+  attentively at one time more then one Physical point; for though there be
+  a distinct Image made in every eye, yet 'tis very likely, that the
+  observing faculty is only imploy'd about some one object for which they
+  have most concern.</p>
+
+  <p>Now, as we accurately distinguish the site or position of an Object by
+  the motion of the Muscles of the eye requisite to put the optick Line in
+  a direct position, and confusedly by the position of the imperfect
+  Picture of the object at the bottom of the eye; so are these
+  <i>crustaceous</i> creatures able to judge confusedly of the position of
+  objects by the Picture or impression made at the bottom of the opposite
+  Pearl, and distinctly by the removal of the attentive or observing
+  faculty, from one Pearl to another, but what this faculty is, as it
+  requires another place, so a much deeper speculation. Now, because it
+  were impossible, even with this multitude of eye-balls, to see any object
+  distinct (for as I hinted before, onely those parts that lay in, or very
+  neer, the optick Lines could be so) the Infinitely wise Creator has not
+  left the creature without a power of moving the head a little in
+  <i>Aerial crustaceous</i> animals, and the very eyes also in
+  <i>crustaceous</i> Sea-animals; so that by these means they are inabled
+  to direct some optick line or other against any object, and by that means
+  they have the visive faculty as compleat as any Animal that can move its
+  eyes.</p>
+
+  <p>Distances of Objects also, 'tis very likely they distinguish, partly
+  by the consonant impressions made in some two convenient Pearls, one in
+  each cluster; for, according as those congruous impressions affect, two
+  Pearls neerer approach'd to each other, the neerer is the Object, and the
+  farther they are distant, the more distant is the Object: partly also by
+  the alteration of each Pearl, requisite to make the Sensation or Picture
+  perfect; for 'tis impossible that the Pictures of two Objects, variously
+  distant, can be perfectly painted, or made on the same <i>Retina</i> or
+  bottom of the eye not altered, as will be very evident to any one that
+  shall attentively consider the nature of refraction. Now, whether this
+  alteration may be in the Figure of the <i>Cornea</i>, in the motion of
+  access or recess of the <i>Retina</i> towards the <i>Cornea</i>, or in
+  the alteration of a crustaline humour, if such there be, I pretend not to
+  determine; though I think we need not doubt, but that there may be as
+  much curiosity of contrivance and structure in every one of these Pearls,
+  as in the eye of a Whale or Elephant, and the almighty's <i>Fiat</i>
+  could as easily cause the existence of the one as the other; and as one
+  day and a thousand years are the same with him, so may one eye and ten
+  thousand.</p>
+
+  <p>This we may be sure of, that the filaments or sensative parts of the
+  <i>Retina</i> must be most exceedingly curious and minute, since the
+  whole Picture it self is such; what must needs the component parts be of
+  that <i>Retina</i>, which distinguishes the part of an object's Picture
+  that must be many millions of millions less then that in a man's eye? And
+  how exceeding curious and subtile must the component parts of the
+  <i>medium</i> that conveys light be, when we find the instrument made for
+  its reception or refraction to be so exceedingly small? we may, I think,
+  from this speculation be sufficiently discouraged from hoping to discover
+  by any optick or other instrument the determinate bulk of the parts of
+  the <i>medium</i> that conveys the pulse of light, since we find that
+  there is not less accurateness shewn in the Figure and polish of those
+  exceedingly minute lenticular surfaces, then in those more large and
+  conspicuous surfaces of our own eyes. And yet can I not doubt, but that
+  there is a determinate bulk of those parts, since I find them unable to
+  enter between the parts of Mercury, which being in motion, must
+  necessarily have pores, as I shall elsewhere shew, and here pass by, as
+  being a digression.</p>
+
+  <p>As concerning the horns FF, the feelers or smellers, GG, the
+  <i>Probascis</i> HH, and I, the hairs and brisles, KK, I shall indeavour
+  to describe in the 42. <i>Observation</i>.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXL" id="obsXL">XL</a>. <i>Of the Teeth of a </i>Snail<i>.</i></h3>
+
+  <p>I have little more to add of the Teeth of a Snail, besides the Picture
+<span class="sidenote">
+<a href="images/scheme-25.png" target="_blank"><i>Schem.</i> 25.</a><br /><i>Fig.</i> 1.
+</span>
+  of it, which is represented in the first <i>Figure</i> of the 25.
+  <i>Scheme</i>, save that his bended body, ABCDEF, which seem'd fashioned
+  very much like a row of small teeth, orderly plac'd in the Gums, and
+  looks as if it were divided into several smaller and
+  greater black teeth, was nothing but one small bended hard bone, which
+  was plac'd in the upper jaw of the mouth of a House-Snail, with which I
+  observ'd this very Snail to feed on the leaves of a Rose-tree, and to
+  bite out pretty large and half round bits, not unlike the Figure of a (C)
+  nor very much differing from it in bigness, the upper part ABCD of this
+  bone, I found to be much whiter, and to grow out of the upper chap of the
+  Snail, GGG, and not to be any thing neer so much creas'd as the lower and
+  blacker part of it HIIHKKH which was exactly shap'd like teeth, the bone
+  growing thinner, or tapering to an edge towards KKK. It seem'd to have
+  nine teeth, or prominent parts IK, IK, IF, <i>&amp;c.</i> which were
+  join'd together by the thinner interpos'd parts of the bone. The Animal
+  to which these teeth belong, is a very <i>anomalous</i> creature, and
+  seems of a kind quite distinct from any other terrestrial Animal or
+  Insect, the Anatomy whereof exceedingly differing from what has been
+  hitherto given of it I should have inserted, but that it will be more
+  proper in another place. I have never met with any kind of Animal whose
+  teeth are all join'd in one, save onely that I lately observ'd, that all
+  the teeth of a Rhinocerot, which grow on either side of its mouth, are
+  join'd into one large bone, the weight of one of which I found to be neer
+  eleven pound <i>Haverdupois</i>. So that it seems one of the biggest sort
+  of terrestrial Animals, as well as one of the smallest, has his teeth
+  thus shap'd.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLI" id="obsXLI">XLI</a>. <i>Of the Eggs of </i>Silk-worms<i>, and other Insects.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-25.png" target="_blank"><i>Schem.</i> 25.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>The Eggs of Silk-worms (one of which I have describ'd in the second
+  <i>Figure</i> of 25. <i>Scheme</i>) afford a pretty Object for a
+  <i>Microscope</i> that magnifies very much, especially if it be bright
+  weather, and the light of a window be cast or collected on it by a deep
+  <i>Convex-glass</i>, or Water-ball. For then the whole surface of the
+  Shell may be perceiv'd all cover'd over with exceeding small pits or
+  cavities with interposed edges, almost in the manner of the surface of a
+  Poppy-seed, but that these holes are not an hundredth part scarce of
+  their bigness; the Shell, when the young ones were hatch'd (which I found
+  an easie thing to do, if the Eggs were kept in a warm place) appear'd no
+  thicker in proportion to its bulk, then that of an Hen's or Goos's Egg is
+  to its bulk, and all the Shell appear'd very white (which seem'd to
+  proceed from its transparency) whence all those pittings did almost
+  vanish, so that they could not, without much difficulty, be discern'd,
+  the inside of the Shell seem'd to be lin'd also with a kind of thin film,
+  not unlike (keeping the proportion to its Shell) that with which the
+  shell of an Hen-egg is lin'd; and the shell it self seem'd like common
+  Egg-shells; very brittle, and crack'd. In divers other of these Eggs I
+  could plainly enough, through the shell, perceive the small Insect lie
+  coyled round the edges of the shell. The shape of the Egg it self, the
+  Figure pretty well represents (though by default of the Graver it does
+  not appear so rounded, and lying above the
+  Paper, as it were, as it ought to do) that is, it was for the most part
+  pretty oval end-ways, somewhat like an Egg, but the other way it was a
+  little flatted on two opposite sides. Divers of these Eggs, as is common
+  to most others, I found to be barren, or addle, for they never afforded
+  any young ones. And those I usually found much whiter then the other that
+  were prolifick. The Eggs of other kinds of Oviparous Insects I have found
+  to be perfectly round every way, like so many Globules, of this sort I
+  have observ'd some sorts of Spiders Eggs; and chancing the last Summer to
+  inclose a very large and curiously painted Butterfly in a Box, intending
+  to examine its gaudery with my <i>Microscope</i>, I found within a day or
+  two after I inclos'd her, almost all the inner surface of the Box cover'd
+  over with an infinite of exactly round Eggs, which were stuck very fast
+  to the sides of it, and in so exactly regular and close an order, that
+  made me call to mind my <i>Hypothesis</i>, which I had formerly thought
+  on for the making out of all the regular Figures of Salt, which I have
+  elsewhere hinted; for here I found all of them rang'd into a most exact
+  <i>triagonal</i> order, much after the manner as the <i>Hemispheres</i>
+  are place on the eye of a Fly; all which Eggs I found after a little time
+  to be hatch'd, and out of them to come a multitude of small Worms, very
+  much resembling young Silk-worms, leaving all their thin hollow shells
+  behind them, sticking on the Box in their <i>triagonal</i> posture; these
+  I found with the <i>Microscope</i> to have much such a substance as the
+  Silk-worms Eggs, but could not perceive them pitted. And indeed, there is
+  as great a variety in the shape of the Eggs of Oviparous Insects as among
+  those of Birds.</p>
+
+  <p>Of these Eggs, a large and lusty Fly will at one time lay neer four or
+  five hundred, so that the increase of these kind of Insects must needs be
+  very prodigious, were they not prey'd on by multitudes of Birds, and
+  destroy'd by Frosts and Rains; and hence 'tis those hotter Climates
+  between the <i>Tropicks</i> are infested with such multitudes of Locusts,
+  and such other Vermine.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLII" id="obsXLII">XLII</a>. <i>Of a blue </i>Fly<i>.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-26.png" target="_blank"><i>Schem.</i> 26.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>This kind of Fly, whereof a <i>Microscopical</i> Picture is delineated
+  in the first <i>Figure</i> of the 26. <i>Scheme</i>, is a very beautifull
+  creature, and has many things about it very notable; divers of which I
+  have already partly describ'd, namely, the feet, wings, eyes, and head,
+  in the preceding Observations.</p>
+
+  <p>And though the head before describ'd be that of a grey
+  <i>Drone-Fly</i>, yet for the main it is very agreeable to this. The
+  things wherein they differ most, will be easily enough found by the
+  following particulars:</p>
+
+  <p>First, the clusters of eyes of this Fly, are very much smaller then
+  those of the <i>Dron-Fly</i>, in proportion to the head.</p>
+
+  <p>And next, all the eyes of each cluster seem'd much of the same bigness
+  one with another, not differing as the other, but rang'd in the same
+  <i>triagonal</i> order.</p>
+
+  <p>Thirdly, between these two clusters, there was a scaly prominent
+  <i>front</i> B, which was arm'd and adorn'd with large tapering sharp
+  black brisles, which growing out in rows on either side, were so bent
+  toward each other neer the top, as to make a kind of arched arbour of
+  Brisles, which almost cover'd the former <i>front</i>.</p>
+
+  <p>Fourthly, at the end of this Arch, about the middle of the face, on a
+  prominent part C, grew two small oblong bodies, DD, which through a
+  <i>Microscope</i> look'd not unlike the Pendants in Lillies, these seem'd
+  to be jointed on to two small parts at C, each of which seem'd again
+  jointed into the front.</p>
+
+  <p>Fifthly, out of the upper part and outsides of these horns (as I may
+<span class="sidenote">
+<a href="images/scheme-24.png" target="_blank"><i>Schem.</i> 24.</a>
+</span>
+  call them, from the Figure they are of, in the 24. <i>Scheme</i>, where
+  they are marked with FF) there grows a single feather, or brushy Brisle,
+  EE, somewhat of the same kind with the tufts of a Gnat, which I have
+  before described.</p>
+
+  <p>What the use of these kind of horned and tufted bodies should be, I
+  cannot well imagine, unless they serve for smelling or hearing, though
+  how they are adapted for either, it seems very difficult to describe:
+  they are in almost every several kind of Flies of so various a shape;
+  though certainly they are some very essential part of the head, and have
+  some very notable office assign'd them by Nature, since in all Insects
+  they are to be found in one or other form.</p>
+
+  <p>Sixthly, at the under part of the face FF, were several of the former
+  sort of bended Brisles, and below all, the mouth, out of the middle of
+  which, grew the <i>proboscis</i> GHI, which, by means of several joints,
+  whereof it seem'd to consist, the Fly was able to move to and fro, and
+  thrust it in and out as it pleas'd; the end of this hollow body (which
+  was all over cover'd with small short hairs or brisles) was, as 'twere,
+  bent at H, and the outer or formost side of the bended part HI, slit, as
+  it were, into two chaps, HI, HI, all the outside of which where cover'd
+  with hairs, and pretty large brisles; these he could, like two chaps,
+  very readily open and shut, and when he seem'd to suck any thing from the
+  surface of a body, he would spread abroad those chaps, and apply the
+  hollow part of them very close to it.</p>
+
+  <p>From either side of the <i>Proboscis</i>, within the mouth, grew two
+  other small horns, or fingers, KK, which were hairy, but small in this
+<span class="sidenote">
+<a href="images/scheme-24.png" target="_blank"><i>Schem.</i> 24.</a>
+</span>
+  Figure; but of another shape, and bigger in proportion, in the 24.
+  <i>Scheme</i>, where they are marked with GG, which two indeed seem'd a
+  kind of smellers, but whether so or not, I cannot positively
+  determine.</p>
+
+  <p>The <i>Thorax</i> or middle part of this Fly, was cas'd, both above
+  and beneath, with a very firm crust of armour, the upper part more round,
+  and covered over with long <i>conical</i> brisles, all whose ends pointed
+  backwards; out of the hinder and under part of this grew out in a cluster
+  six leggs, three of which are apparent in the Figure, the other three
+  were hid by the body plac'd in that posture. The leggs were
+  all much of the same make, being all of them cover'd with a strong hairy
+  scale or shel, just like the legs of a Crabb or Lobster, and the
+  contrivance of the joints seem'd much the same, each legg seem'd made up
+  of eight parts, 1, 2, 3, 4, 5, 6, 7, 8, to the eighth or last of which,
+  grew the soles and claws, described before in the 38.
+  <i>Observation</i>.</p>
+
+  <p>Out of the upper part of this trunck grew the two wings, which I
+  mention'd in the 38. <i>Observation</i>, consisting of a film, extended
+  on certain small stiff wires or bones: these in a blue Fly, were much
+  longer then the body, but in other kind of Flies they are of very
+  differing proportions to the body. These films, in many Flies, were so
+  thin, that, like several other plated bodies (mention'd in the ninth
+  <i>Observation</i>) they afforded all varieties of fantastical or
+  transient colours (the reason of which I have here endeavoured to
+  explain) they seem'd to receive their nourishment from the stalks or
+  wires, which seem'd to be hollow, and neer the upper part of the wing LL
+  several of them seem'd jointed, the shape of which will sufficiently
+<span class="sidenote">
+<a href="images/scheme-26.png" target="_blank"><i>Schem.</i> 26.</a>
+</span>
+  appear by the black lines in the second Figure of the 26. <i>Scheme</i>,
+  which is a delineation of one of those wings expanded directly to the
+  eyes.</p>
+
+  <p>All the hinder part of its body is cover'd with a most curious blue
+  shining armour, looking exactly like a polish'd piece of steel brought to
+  that blue colour by annealing, all which armour is very thick bestuck
+  with abundance of tapering brisles, such as grow on its back, as is
+  visible enough by the Figure.</p>
+
+  <p>Nor was the inside of this creature less beautifull then its outside,
+  for cutting off a part of the belly, and then viewing it, to see if I
+  could discover any Vessels, such as are to be found in a greater Animals,
+  and even in Snails exceeding manifestly, I found, much beyond my
+  expectation, that there were abundance of branchings of Milk-white
+  vessels, no less curious then the branchings of veins and arteries in
+  bigger terrestrial Animals, in one of which, I found two notable
+  branches, joining their two main stocks, as it were, into one common
+  <i>ductus</i>; now, to what veins or arteries these Vessells were
+  <i>analogus</i>, whether to the <i>vena porta</i>, or the <i>meseraick
+  vessells</i>, or the like, or indeed, whether they were veins and
+  arteries, or <i>vasa lactea</i>, properly so called, I am not hitherto
+  able to determine, having not yet made sufficient enquiry; but in all
+  particulars, there seems not to be any thing less of curious contrivance
+  in these Insects, then in those larger terrestrial Animals, for I had
+  never seen any more curious branchings of Vessels, then those I observ'd
+  in two or three of these Flies thus opened.</p>
+
+  <p>It is a creature active and nimble, so as there are very few creatures
+  like it, whether bigger or smaller, in so much, that it will scape and
+  avoid a small body, though coming on it exceeding swiftly, and if it sees
+  any thing approaching it, which it fears, it presently squats down, as it
+  were, that it may be the more ready for its rise.</p>
+
+  <p>Nor is it less hardy in the Winter, then active in the Summer,
+  induring all the Frosts, and surviving till the next Summer,
+  notwithstanding the bitter cold of our Climate;
+  nay, this creature will indure to be frozen, and yet not be destroy'd,
+  for I have taken one of them out of the Snow whereon it has been frozen
+  almost white, with the Ice about it, and yet by thawing it gently by the
+  warmth of a fire, it has quickly reviv'd and flown about.</p>
+
+  <p>This kind of Fly seems by the steams or taste of fermenting and
+  putrifying meat (which it often kisses, as 'twere, with its
+  <i>proboscis</i> as it trips over it) to be stimulated or excited to
+  eject its Eggs or Seed on it, perhaps, from the same reason as Dogs,
+  Cats, and many other brute creatures are excited to their particular
+  lusts, by the smell of their females, when by Nature prepared for
+  generation; the males seeming by those kind of smells, or other
+  incitations, to be as much necessitated thereto, as <i>Aqua Regis</i>
+  strongly impregnated with a solution of Gold, is forced to precipitate it
+  by the affusion of spirit of <i>Urine</i>, or a solution of <i>Salt</i>
+  of <i>Tartar</i>.</p>
+
+  <p>One of these put in spirit of <i>Wine</i>, was very quickly seemingly
+  kill'd, and both its eys and mouth began to look very red, but upon the
+  taking of it out, and suffering it to lie three or four hours, and
+  heating it with the Sun beams cast through a Burning-glass, it again
+  reviv'd, seeming, as it were, to have been all the intermediate time, but
+  dead drunk, and after certain hours to grow fresh again and sober.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLIII" id="obsXLIII">XLIII</a>. <i>Of the </i>Water-Insect<i> or </i>Gnat<i>.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-27.png" target="_blank"><i>Schem.</i> 27.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>This little creature, described in the first <i>Figure</i> of the 27.
+  <i>Scheme</i>, was a small scaled or crusted Animal, which I have often
+  observ'd to be generated in Rain-water; I have also observ'd it both in
+  Pond and River-water. It is suppos'd by some, to deduce its first
+  original from the putrifaction of Rain-water, in which, if it have stood
+  any time open to the air, you shall seldom miss, all the Summer long, of
+  store of them frisking too and fro.</p>
+
+  <p>'Tis a creature, wholly differing in shape from any I ever observ'd;
+  nor is its motion less strange: It has a very large head, in proportion
+  to its body, all covered with a shell, like other <i>testaceous</i>
+  Animals, but it differs in this, that it has, up and down several parts
+  of it, several tufts of hairs, or brisles, plac'd in the order express'd
+  in the Figure; It has two horns, which seem'd almost like the horns of an
+  Oxe, inverted, and, as neer as I could guess, were hollow, with tufts of
+  brisles, likewise at the top; these horns they could move easily this or
+  that way, and might, perchance, be their nostrils. It has a pretty large
+  mouth, which seem'd contriv'd much like those of Crabs and Lobsters, by
+  which, I have often observ'd them to feed on water, or some imperceptible
+  nutritive substance in it.</p>
+
+  <p>I could perceive, through the transparent shell, while the Animal
+  surviv'd, several motions in the head, thorax, and belly, very
+  distinctly, of differing kinds which I may, perhaps,
+  elsewhere endeavour more accurately to examine, and to shew of how great
+  benefit the use of a <i>Microscope</i> may be for the discovery of
+  Nature's course in the operations perform'd in Animal bodies, by which we
+  have the opportunity of observing her through these delicate and pellucid
+  teguments of the bodies of Insects acting according to her usual course
+  and way, undisturbed, whereas, when we endeavour to pry into her secrets
+  by breaking open the doors upon her, and dissecting and mangling
+  creatures whil'st there is life yet within them, we find her indeed at
+  work, but put into such disorder by the violence offer'd, as it may
+  easily be imagin'd, how differing a thing we should find, if we could, as
+  we can with a <i>Microscope</i> in these smaller creatures, quietly peep
+  in at the windows, without frighting her out of her usual byas.</p>
+
+  <p>The form of the whole creature, as it appear'd in the
+  <i>Microscope</i>, may, without troubling you with more descriptions, be
+  plainly enough perceiv'd by the <i>Scheme</i>, the hinder part or belly
+  consisting of eight several jointed parts, namely, ABCDEFGH, of the first
+  <i>Figure</i>, from the midst of each of which, on either side issued out
+  three or four small brisles or hairs, I, I, I, I, I, the tail was divided
+  into two parts of very differing make; one of them, namely, K, having
+  many tufts of hair or brisles, which seem'd to serve both for the finns
+  and tail, for the Oars and Ruder of this little creature, wherewith it
+  was able, by frisking and bending its body nimbly to and fro, to move
+  himself any whither, and to skull and steer himself as he pleas'd, the
+  other part, L, seem'd to be, as 'twere, the ninth division of his belly,
+  and had many single brisles on either side. From the end V, of which,
+  through the whole belly, there was a kind of Gut of a darker colour, MMM,
+  wherein, by certain <i>Peristaltick</i> motions there was a kind of black
+  substance mov'd upwards and downwards through it from the orbicular part
+  of it, N, (which seem'd the <i>Ventricle</i>, or stomach) to the tail V,
+  and so back again, which <i>peristaltick</i> motion I have observ'd also
+  in a Louse, a Gnat, and several other kinds of transparent body'd Flies.
+  The <i>Thorax</i> or chest of this creature OOOO, was thick and short,
+  and pretty transparent, for through it I could see the white heart (which
+  is the colour also of the bloud in these, and most other Insects) to
+  beat, and several other kind of motions. It was bestuck and adorn'd up
+  and down with several tufts of brisles, such as are pointed out by P, P,
+  P, P, the head Q was likewise bestuck with several of those tufts, SSS;
+  it was broad and short, had two black eyes, TT, which I could not
+  perceive at all pearl'd, as they afterwards appear'd, and two small
+  horns, RR, such as I formerly describ'd.</p>
+
+  <p>Both its motion and rest is very strange, and pleasant, and differing
+  from those of most other creatures I have observ'd; for, where it ceases
+  from moving its body, the tail of it seeming much lighter then the rest
+  of its body, and a little lighter then the water it swims in, presently
+  boys it up to the top of the water, where it hangs suspended with the
+  head always downward; and like our <i>Antipodes</i>, if they do by a
+  frisk get below that superficies, they presently ascend again unto it, if
+  they cease moving, until they tread, as it were, under
+  that superficies with their tails; the hanging of these in this posture,
+  put me in mind of a certain creature I have seen in <i>London</i>, that
+  was brought out of <i>America</i>, which would very firmly suspend it
+  self by the tail, with the head downwards, and was said to keep in that
+  posture, with her young ones in her false belly, which is a Purse,
+  provided by Nature for the production, nutrition, and preservation of her
+  young ones, which is described by <i>Piso</i> in the 24. Chapter of the
+  fifth Book of his Natural History of <i>Brasil</i>.</p>
+
+  <p>The motion of it was with the tail forwards, drawing its self
+  backwards, by the striking to and fro of that tuft which grew out of one
+  of the stumps of its tail. It had another motion, which was more sutable
+  to that of other creatures, and that is, with the head forward; for by
+  the moving of his chaps (if I may so call the parts of his mouth) it was
+  able to move it self downwards very gently towards the bottom, and did,
+  as 'twere, eat up its way through the water.</p>
+
+  <p>But that which was most observable in this creature, was, its
+  Metamorphosis or change; for having kept several of these Animals in a
+  Glass of Rain-water, in which they were produc'd, I found, after about a
+  fortnight or three weeks keeping, that several of them flew away in
+  Gnats, leaving their husks behind them in the water floating under the
+  surface, the place where these Animals were wont to reside, whil'st they
+  were inhabitants of the water: this made me more diligently to watch
+  them, to see if I could find them at the time of their transformation;
+  and not long after, I observ'd several of them to be changed into an
+  unusual shape, wholly differing from that they were of before, their head
+  and body being grown much bigger and deeper, but not broader, and their
+  belly, or hinder part smaller, and coyl'd, about this great body much of
+<span class="sidenote">
+<a href="images/scheme-27.png" target="_blank"><i>Schem.</i> 27.</a><br /><i>Fig.</i> 2.
+</span>
+  the fashion represented by the prick'd line in the second <i>Figure</i>
+  of the 27. <i>Scheme</i>, the head and horns now swam uppermost, and the
+  whole bulk of the body seem'd to be grown much lighter; for when by my
+  frighting of it, it would by frisking out of its tail (in the manner
+  express'd in the Figure by BC) sink it self below the surface towards the
+  bottom; the body would more swiftly re-ascend, then when it was in its
+  former shape.</p>
+
+  <p>I still marked its progress from time to time, and found its body
+  still to grow bigger and bigger, Nature, as it were, fitting and
+  accoutring it for the lighter Element, of which it was now going to be an
+  inhabitant; for, by observing one of these with my <i>Microscope</i>, I
+  found the eyes of it to be altogether differing from what they seem'd
+  before, appearing now all over pearl'd or knobb'd, like the eyes of
+  Gnats, as is visible in the second <i>Figure</i> by A. At length, I saw
+  part of this creature to swim above, and part beneath the surface of the
+  water, below which though it would quickly plunge it self if I by any
+  means frighted it, and presently re-ascend into its former posture; after
+  a little longer expectation, I found that the head and body of a Gnat,
+  began to appear and stand cleer above the surface, and by degrees it drew
+  out its leggs, first the two formost, then the other, at length its whole
+  body perfect and entire appear'd out of the husk (which it left in the
+  water) standing on its leggs upon the top
+  of the water, and by degrees it began to move, and after flew about the
+  Glass a perfect Gnat.</p>
+
+  <p>I have been the more particular, and large in the relation of the
+  transformation of divers of these little Animals which I observ'd,
+  because I have not found that any Authour has observ'd the like, and
+  because the thing it self is so strange and heterogeneous from the usual
+  progress of other Animals, that I judge it may not onely be pleasant, but
+  very usefull and necessary towards the compleating of Natural
+  History.</p>
+
+  <p>There is indeed in <i>Piso</i>, a very odd History, which this
+  relation may make the more probable; and that is in the 2. Chapter of the
+  4. Book of his Natural History of <i>Brasil</i>, where he says, <i>Porro
+  præter tot documenta fertilitatis circa vegetabilia &amp; sensitiva
+  marina telluris æmula, accidit &amp; illud, quod paucis à Paranambucensi
+  milliaribus, piscatoris uncum citra intentionem contingat infigi vadis
+  petrosis, &amp; loco piscis spongia, coralla, aliasque arbusculas marinas
+  capi. Inter hæc inusitatæ formæ prodit spongiosa arbuscula sesquipedis
+  longitudinis, brevioribus radicibus, lapideis nitens vadis, &amp; rupibus
+  infixa, erigiturque in corpus spongiosum molle oblongum rotundum
+  turbinatum: intus miris cancellis &amp; alveis fabricatum, extus autem
+  tenaci glutine instar Apum propolis undique vestitum, ostio satis patulo
+  &amp; profundo in summitate relicto, sicut ex altera iconum probe depicta
+  videre licet </i>(see
+<span class="sidenote">
+<a href="images/scheme-27.png" target="_blank"><i>Schem.</i> 27.</a><br /><i>Fig.</i> 3. &amp; 4.
+</span>
+  the third and fourth <i>Figures</i> of the 27.
+  <i>Scheme</i>.)<i> Ita ut Apiarium marinum vere dixeris; primo enim
+  intuitu è Mare ad Terram delatum, vermiculis scatebat cæruleis parvis,
+  qui mox à calore solis in Muscas, vel Apes potius, easq; exiguas &amp;
+  nigras transformebantur, circumvolantesque evanescebant, ita ut de eorum
+  mellificatione nihil certi conspici datum fuerit, cum tamen cærosa
+  materia propolis Apumque cellæ manifeste apparerent, atque ipsa mellis
+  qualiscunque substantia proculdubio urinatoribus patebit, ubi curiosius
+  inquisiverint hæc apiaria, eaque in natali solo &amp; salo diversis
+  temporibus penitius lustrarint</i>.</p>
+
+  <p>Which History contains things sufficiently strange to be consider'd,
+  as whether the husk were a Plant, growing at the bottom of the Sea
+  before, of it self, out of whose putrifaction might be generated these
+  strange kind of Magots; or whether the seed of certain Bees, sinking to
+  the bottom, might there naturally form it self that vegetable hive, and
+  take root; or, whether it might not be placed there by some diving Fly;
+  or, whether it might not be some peculiar propriety of that Plant,
+  whereby it might ripen or form its vegetable juice into an Animal
+  substance; or, whether it may not be of the nature of a Sponge, or rather
+  a Sponge of the nature of this, according to some of those relations and
+  conjectures I formerly made of that body, is a matter very difficult to
+  be determined. But indeed, in this description, the Excellent <i>Piso</i>
+  has not been sufficiently particular in the setting down the whole
+  process, as it were to be wish'd: There are indeed very odd progresses in
+  the production of several kinds of Insects, which are not less
+  instructive then pleasant, several of which, the diligent
+  <i>Goedartius</i> has carefully observ'd and recorded, but among all his
+  Observations, he has none like this, though that of the <i>Hemerobius</i>
+  be somewhat of this kind, which is added as an Appendix by <i>Johannes
+  Mey</i>.</p>
+
+  <p>I have, for my own particular, besides several of those mention'd by
+  him, observ'd divers other circumstances, perhaps, not much taken notice
+  of, though very common, which do indeed afford us a very <i>coercive</i>
+  argument to admire the goodness and providence of the infinitely wise
+  Creator in his most excellent contrivances and dispensations. I have
+  observ'd, at several times of the Summer, that many of the leaves of
+  divers Plants have been spotted, or, as it were scabbed, and looking on
+  the undersides of those of them that have been but a litte irregular, I
+  have perceiv'd them to be sprinkled with divers sorts of little Eggs,
+  which letting alone, I have found by degrees to grow bigger, and become
+  little Worms with leggs, but still to keep their former places, and those
+  places of the leaves, of their own accords, to be grown very protuberant
+  upwards, and very hollow, and arched underneath, whereby those young
+  creatures are, as it were, shelter'd and housed from external injury;
+  divers leaves I have observ'd to grow and swell so farr, as at length
+  perfectly to inclose the Animal, which, by other observations I have
+  made, I ghess to contain it, and become, as it were a womb to it, so
+  long, till it be fit and prepar'd to be translated into another state, at
+  what time, like (what they say of) Vipers, they gnaw their way through
+  the womb that bred them; divers of these kinds I have met with upon
+  Goosberry leaves, Rose-tree leaves, Willow leaves, and many other
+  kinds.</p>
+
+  <p>There are often to be found upon Rose-trees and Brier bushes, little
+  red tufts, which are certain knobs or excrescencies, growing out from the
+  Rind, or barks of those kinds of Plants, they are cover'd with strange
+  kinds of threads or red hairs, which feel very soft, and look not
+  unpleasantly. In most of these, if it has no hole in it, you shall find
+  certain little Worms, which I suppose to be the causes of their
+  production; for when that Worm has eat its way through, they, having
+  performed what they were design'd by Nature to do, by degrees die and
+  wither away.</p>
+
+  <p>Now, the manner of their production, I suppose to be thus, that the
+  Alwise Creator has as well implanted in every creature a faculty of
+  knowing what place is convenient for the hatching, nutrition, and
+  preservation of their Eggs and of-springs whereby they are stimulated and
+  directed to convenient places, which becom, as 'twere the wombs that
+  perform those offices: As he has also suited and adapted a property to
+  those places wherby they grow and inclose those seeds, and having
+  inclosed them, provide a convenient nourishment for them, but as soon as
+  they have done the office of a womb, they die and wither.</p>
+
+  <p>The progress of inclosure I have often observ'd in leaves, which in
+  those places where those seeds have been cast, have by degrees swell'd
+  and inclos'd them, so perfectly round, as not to leave any perceptible
+  passage out.</p>
+
+  <p>From this same cause, I suppose that Galls, Oak-apples, and several
+  other productions of that kind, upon the branches and leaves of Trees,
+  have their original, for if you open any of them, when almost ripe, you
+  shall find a little Worm in them. Thus, if you open never so many dry
+  Galls, you shall find either a hole whereby the Worm has eat its passage
+  out, or if you find no passage, you may, by
+  breaking or cutting the Gall, find in the middle of it a small cavity,
+  and in it a small body, which does plainly enough yet retain a shape, to
+  manifest it once to have been a Worm, though it dy'd by a too early
+  reparation from the Oak on which it grew, its navel-string, as 'twere,
+  being broken off from the leaf or branch by which the Globular body that
+  invelop'd it, received its nourishment from the Oak.</p>
+
+  <p>And indeed, if we consider the great care of the Creator in the
+  dispensations of his providences for the propagation and increase of the
+  race, not onely of all kind of Animals, but even of Vegetables, we cannot
+  chuse but admire and adore him for his Excellencies, but we shall leave
+  off to admire the creature, or to wonder at the strange kind of acting in
+  several Animals, which seem to favour so much of reason; it seeming to me
+  most manifest, that those are but actings according to their structures,
+  and such operations as such bodies, so compos'd, must necessarily, when
+  there are such and such circumstances concurring, perform: thus, when we
+  find Flies swarming, about any piece of flesh that does begin a little to
+  ferment; Butterflies about Colworts, and several other leaves, which will
+  serve to hatch and nourish their young; Gnats, and several other Flies
+  about the Waters, and marishy places, or any other creatures, seeking and
+  placing their Seeds in convenient repositories, we may, if we attentively
+  consider and examine it, find that there are circumstances sufficient,
+  upon the supposals of the excellent contrivance of their machine, to
+  excite and force them to act after such or such a manner; those steams
+  that rise from these several places may, perhaps, set several parts of
+  these little Animals at work, even as in the contrivance of killing a Fox
+  or Wolf with a Gun, the moving of a string, is the death of the Animal;
+  for the Beast, by moving the flesh that is laid to entrap him, pulls the
+  string which moves the trigger, and that lets go the Cock which on the
+  steel strikes certain sparks of fire which kindle the powder in the pann,
+  and that presently flies into the barrel, where the powder catching fire
+  rarifies and drives out the bullet which kills the Animal; in all which
+  actions, there is nothing of intention or ratiocination to be ascrib'd
+  either to the Animal or Engine, but all to the ingeniousness of the
+  contriver.</p>
+
+  <p>But to return to the more immediate consideration of our Gnat: We have
+  in it an Instance, not usual or common, of a very strange
+  <i>amphibious</i> creature, that being a creature that inhabits the Air,
+  does yet produce a creature, that for some time lives in the water as a
+  Fish, though afterward (which is as strange) it becomes an inhabitant of
+  the Air, like its Sire, in the form of a Fly. And this, methinks, does
+  prompt me to propose certain conjectures, as Queries, having not yet had
+  sufficient opportunity and leisure to answer them my self from my own
+  Experiments or Observations.</p>
+
+  <p>And the first is, Whether all those things that we suppose to be bred
+  from corruption and putrifaction, may not be rationally suppos'd to have
+  their origination as natural as these Gnats, who, 'tis very probable,
+  were first dropt into this Water, in the form of Eggs. Those Seeds or
+  Eggs must certainly be very small, which so
+  small a creature as a Gnat yields, and therefore, we need not wonder that
+  we find not the Eggs themselves, some of the younger of them, which I
+  have observ'd, having not exceeded a tenth part of the bulk they have
+  afterwards come to; and next, I have observed some of those little ones
+  which must have been generated after the Water was inclosed in the
+  Bottle, and therefore most probably from Eggs, whereas those creatures
+  have been suppos'd to be bred of the corruption of the Water, there being
+  not formerly known any probable way how they should be generated.</p>
+
+  <p>A second is, whether these Eggs are immediately dropt into the Water
+  by the Gnats themselves, or, mediately, are brought down by the falling
+  rain; for it seems not very improbable, but that those small seeds of
+  Gnats may (being, perhaps, of so light a nature, and having so great a
+  proportion of surface to so small a bulk of body) be ejected into the
+  Air, and so, perhaps, carried for a good while too and fro in it, till by
+  the drops of Rain it be wash'd out of it.</p>
+
+  <p>A third is, whether multitudes of those other little creatures that
+  are found to inhabit the Water for some time, do not, at certain times,
+  take wing and fly into the Air, others dive and hide themselves in the
+  Earth, and so contribute to the increase both of the one and the other
+  Element.</p>
+
+  <br clear="all" />
+<hr />
+
+<h3><i>Postscript.</i></h3>
+
+  <p>A good while since the writing of this Description, I was presented by
+  Doctor <i>Peter Ball</i>, an ingenious Member of the <i>Royal
+  Society</i>, with a little Paper of Nuts, which he told me was sent him
+  from a Brother of his out of the Countrey, from <i>Mamhead</i> in
+  <i>Devonshire</i>, some of them were loose, having been, as I suppose,
+  broken off, others were still growing fast on upon the sides of a stick,
+  which seem'd by the bark, pliableness of it, and by certain strings that
+  grew out of it, to be some piece of the root of a Tree; they were all of
+  them dry'd, and a little shrivell'd, others more round, of a brown
+  colour; their shape was much like a Figg, but very much smaller, some
+  being about the bigness of a Bay-berry, others, and the biggest, of a
+  Hazel-Nut. Some of these that had no hole in them, I carefully opened
+  with my Knife, and found in them a good large round white Maggot, almost
+  as bigg as a small Pea, which seem'd shap'd like other Maggots, but
+  shorter. I could not find them to move, though I ghess'd them to be
+  alive, because upon pricking them with a Pinn, there would issue out a
+  great deal of white <i>mucous</i> matter, which seem'd to be from a
+  voluntary contraction of their skin; their husk or matrix consisted of
+  three Coats, like the barks of Trees, the outermost being more rough and
+  spongie, and the thickest, the middlemost more close, hard, white, and
+  thin, the innermost very thin, seeming almost like the skin within an
+  Egg's shell. The two outermost had root in the branch or stick, but the
+  innermost had no stem or process, but was onely a skin that cover'd the
+  cavity of the Nut. All the Nuts that had no holes eaten in them, I found
+  to contain these Maggots, but all that had holes, I found empty, the
+  Maggots, it seems, having eaten their way through,
+  taken wings and flown away, as this following account (which I receiv'd
+  in writing from the same person, as it was sent him by his Brother)
+  manifests. <i>In a moorish black Peaty mould, with some small veins of
+  whitish yellow Sands, upon occasion of digging a hole two or three foot
+  deep, at the head of a Pond or Pool, to set a Tree in, at that depth,
+  were found, about the end of </i>October 1663.<i> in those very veins of
+  Sand, those Buttons or Nuts, sticking to a little loose stick, that is,
+  not belonging to any live Tree, and some of them also free by
+  themselves.</i></p>
+
+  <p><i>Four or five of which being then open'd, some were found to contain
+  live Insects come to perfection, most like to flying </i>Ants<i>, if not
+  the same; in others, Insects, yet imperfect, having but the head and
+  wings form'd, the rest remaining a soft white pulpy substance.</i></p>
+
+  <p>Now, as this furnishes us with one odd History more, very agreeable to
+  what I before hinted, so I doubt not, but were men diligent observers,
+  they might meet with multitudes of the same kind, both in the Earth and
+  in the Water, and in the Air, on Trees, Plants, and other Vegetables, all
+  places and things being, as it were, <i>animarum plena</i>. And I have
+  often, with wonder and pleasure, in the Spring and Summer-time, look'd
+  close to, and diligently on, common Garden mould, and in a very small
+  parcel of it, found such multitudes and diversities of little
+  <i>reptiles</i>, some in husks, others onely creepers, many wing'd, and
+  ready for the Air; divers husks or habitations left behind empty. Now, if
+  the Earth of our cold Climate be so fertile of animate bodies, what may
+  we think of the fat Earth of hotter Climates? Certainly, the Sun may
+  there, by its activity, cause as great a parcel of Earth to fly on wings
+  in the Air, as it does of Water in steams and vapours. And what swarms
+  must we suppose to be sent out of those plentifull inundations of water
+  which are poured down by the sluces of Rain in such vast quantities? So
+  that we need not much wonder at those innumerable clouds of Locusts with
+  which <i>Africa</i>, and other hot countries are so pestred, since in
+  those places are found all the convenient causes of their production,
+  namely, genitors, or Parents, concurrent receptacles or matrixes, and a
+  sufficient degree of natural heat and moisture.</p>
+
+  <p>I was going to annex a little draught of the Figure of those Nuts sent
+  out of <i>Devonshire</i>, but chancing to examine Mr. <i>Parkinson</i>'s
+  Herbal for something else, and particularly about Galls and Oak-apples, I
+  found among no less then 24. several kinds of excrescencies of the Oak,
+  which I doubt not, but upon examination, will be all found to be the
+  <i>matrixes</i> of so many several kinds of Insects; I having observ'd
+  many of them my self to be so, among 24. several kinds, I say, I found
+  one described and Figur'd directly like that which I had by me, the
+  <i>Scheme</i> is there to be seen, the description, because but short, I
+  have here adjoin'd <i>Theatri Botanici trib. 16. Chap. 2. There groweth
+  at the roots of old Oaks in the Spring-time, and semetimes also in the
+  very heat of Summer, a peculiar kind of Mushrom or Excrescence, call'd
+  </i>Uva Quercina<i>, swelling out of the Earth, many growing one close
+  unto another, of the fashion of a Grape, and therefore took the name, the
+  </i>Oak-Grape<i>, and is of a Purplish colour on the outside,
+  and white within like Milk, and in the end
+  of Summer becometh hard and woody.</i> Whether this be the very same
+  kind, I cannot affirm, but both the Picture and Description come very
+  neer to that I have, but that he seems not to take notice of the
+  hollowness or Worm, for which 'tis most observable. And therefore 'tis
+  very likely, if men did but take notice, they might find very many
+  differing Species of these Nuts, <i>Ovaries</i>, or <i>Matrixes</i>, and
+  all of them to have much the same designation and office. And I have very
+  lately found several kinds of Excrescencies on Trees and Shrubs, which
+  having endured the Winter, upon opening them, I found most of them to
+  contain little Worms, but dead, those things that contain'd them being
+  wither'd and dry.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLIV" id="obsXLIV">XLIV</a>. <i>Of the tufted or Brush-horn'd </i>Gnat<i>.</i></h3>
+
+  <p>This little creature was one of those multitudes that fill our
+  <i>English</i> air all the time that warm weather lasts, and is exactly
+  of the shape of that I observ'd to be generated and hatch'd out of those
+  little Insects that wriggle up and down in Rain-water. But, though many
+  were of this form, yet I observ'd others to be of quite other kinds; nor
+  were all of this or the other kind generated out of Water Insects; for
+  whereas I observ'd that those that proceeded from those Insects were at
+  their full growth, I have also found multitudes of the same shape, but
+  much smaller and tenderer seeming to be very young ones, creep up and
+  down upon the leaves of Trees, and flying up and down in small clusters,
+  in places very remote from water; and this Spring, I observ'd one day,
+  when the Wind was very calm, and the afternoon very fair, and pretty
+  warm, though it had for a long time been very cold weather, and the wind
+  continued still in the East, several small swarms of them playing to and
+  fro in little clouds in the Sun, each of which were not a tenth part of
+  the bigness of one of these I here have delineated, though very much of
+  the same shape, which makes me ghess, that each of these swarms might be
+  the of-spring of one onely Gnat, which had been hoorded up in some safe
+  repository all this Winter by some provident Parent, and were now, by the
+  warmth of the Spring-air, hatch'd into little Flies.</p>
+
+  <p>And indeed, so various, and seemingly irregular are the generations or
+  productions of Insects, that he that shall carefully and diligently
+  observe the several methods of Nature therein, will have infinitely cause
+  further to admire the wisdom and providence of the Creator; for not onely
+  the same kind of creature may be produc'd from several kinds of ways, but
+  the very same creature may produce several kinds: For, as divers Watches
+  may be made out of several materials, which may yet have all the same
+  appearance, and move after the same manner, that is, shew the hour
+  equally true, the one as the other, and out of the same kind of matter,
+  like Watches, may be wrought differing ways; and, as one and the same
+  Watch may, by being diversly agitated, or mov'd,
+  by this or that agent, or after this or that manner, produce a quite
+  contrary effect: So may it be with these most curious Engines of Insect's
+  bodies; the All-wise God of Nature, may have so ordered and disposed the
+  little <i>Automatons</i>, that when nourished, acted, or enlivened by
+  this cause, they produce one kind of effect, or animate shape, when by
+  another they act quite another way, and another Animal is produc'd. So
+  may he so order several materials, as to make them, by several kinds of
+  methods, produce similar <i>Automatons</i>.</p>
+
+  <p>But to come to the Description of this Insect, as it appears through a
+<span class="sidenote">
+<a href="images/scheme-28.png" target="_blank"><i>Schem.</i> 28.</a>
+</span>
+  <i>Microscope</i>, of which a representation is made in the 28.
+  <i>Scheme</i>. Its head A, is exceeding small, in proportion to its body,
+  consisting of two clusters of pearl'd eyes BB, on each side of its head,
+  whose pearls or eye-balls are curiously rang'd like those of other Flies;
+  between these, in the forehead of it, there are plac'd upon two small
+  black balls, CC, two long jointed horns, tapering towards the top, much
+  resembling the long horns of Lobsters, each of whose stems or quills, DD,
+  were brisled or brushed with multitudes of small stiff hairs, issuing out
+  every way from the several joints, like the strings or sproutings of the
+  herb <i>Horse-tail</i>, which is oft observ'd to grow among Corn, and for
+  the whole shape, it does very much resemble those <i>brushy
+  Vegetables</i>; besides these, there are two other jointed and brisled
+  horns, or feelers, EE, in the forepart of the head, and a
+  <i>proboscis</i>, F, underneath, which in some Gnats are very long,
+  streight hollow pipes, by which these creatures are able to drill and
+  penetrate the skin, and thence, through those pipes suck so much bloud as
+  to stuff their bellies so full till they be ready to burst.</p>
+
+  <p>This small head, with its appurtenances, is fastned on by a short
+  neck, G, to the middle of the <i>thorax</i>, which is large, and seems
+  cased with a strong black shel, HIK, out of the under part of which,
+  issue six long and slender legs, LLLLLL, shap'd just like the legs of
+  Flies, but spun or drawn out longer and slenderer, which could not be
+  express'd in the Figure, because of their great length; and from the
+  upper part, two oblong, but slender transparent wings, MM, shaped
+  somewhat like those of a Fly, underneath each of which, as I have
+  observ'd also in divers sorts of Flies, and other kinds of Gnats, was
+  placed a small body, N, much resembling a drop of some transparent
+  glutinous substance, hardned or cool'd, as it was almost ready to fall,
+  for it has a round knob at the end, which by degrees grows slenderer into
+  a small stem, and neer the insertion under the wing, this stem again
+  grows bigger; these little <i>Pendulums</i>, I may so call them, the
+  litle creature vibrates to and fro very quick when it moves its wings,
+  and I have sometimes observ'd it to move them also, whil'st the wing lay
+  still, but always their motion seem'd to further the motion of the wing
+  ready to follow; of what use they are, as to the moving of the wing, or
+  otherwise, I have not now time to examine.</p>
+
+  <p>Its belly was large, as it is usually in all Insects, and extended
+  into nine lengths or partitions, each of which was cover'd with round
+  armed rings or shells; six of which, OPQRST were transparent, and divers
+  kinds of <i>Peristaltick</i> motions might be very easily perceiv'd,
+  whil'st the Animal was alive, but especially a
+  small cleer white part V, seemed to beat like the heart of a larger
+  Animal. The last three divisios, WXY, were cover'd with black and opacous
+  shells. To conclude, take this creature altogether, and for beauty and
+  curious contrivances, it may be compared with the largest Animal upon the
+  Earth. Nor doth the Alwise Creator seem to have shewn less care and
+  providence in the fabrick of it, then in those which seem most
+  considerable.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLV" id="obsXLV">XLV</a>. <i>Of the great Belly'd </i>Gnat<i> or female </i>Gnat<i>.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-29.png" target="_blank"><i>Schem.</i> 29.</a>
+</span>
+  <p>The second Gnat, delineated in the twenty ninth <i>Scheme</i>, is of a
+  very differing shape from the former; but yet of this sort also, I found
+  several of the Gnats, that were generated out of the Water Insect: the
+  wings of this, were much larger then those of the other, and the belly
+  much bigger, shorter and of an other shape; and, from several
+  particulars, I ghest it to be the Female Gnat, and the former to be the
+  Male.</p>
+
+  <p>The <i>thorax</i> of this, was much like that of the other, having a
+  very strong and ridged back-piece, which went also on either side of its
+  leggs; about the wings there were several joynted pieces of Armor, which
+  seem'd curiously and conveniently contriv'd, for the promoting and
+  strengthning the motion of the wings: its head was much differing from
+  the other, being much bigger and neater shap'd, and the horns that grew
+  out between his eyes on two little balls, were of a very differing shape
+  from the tufts of the other Gnat, these having but a few knots or joynts,
+  and each of those but a few, and those short and strong, brisles. The
+  formost horns or feelers, were like those of the former Gnat.</p>
+
+  <p>One of these Gnats I have suffer'd to pierce the skin of my hand, with
+  its <i>proboscis</i>, and thence to draw out as much blood as to fill its
+  belly as full as it could hold, making it appear very red and
+  transparent; and this without any further pain, then whilst it was
+  sinking in its <i>proboscis</i>, as it is also in the stinging of Fleas:
+  a good argument, that these creatures do not wound the skin, and suck the
+  blood out of enmity and revenge, but for meer necessity, and to satisfy
+  their hunger. By what means this creature is able to suck, we shall shew
+  in another place.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLVI" id="obsXLVI">XLVI</a>. <i>Of the white featherwing'd </i>Moth<i> or </i>Tinea
+Argentea<i>.</i></h3>
+
+<span class="sidenote">
+<a href="images/scheme-30.png" target="_blank"><i>Schem.</i> 30.</a>
+</span>
+  <p>This white long wing'd Moth, which is delineated in the 30.
+  <i>Scheme</i>; afforded a lovely object both to the naked Eye, and
+  through a <i>Microscope</i>: to the Eye it appear'd a small Milk white
+  Fly with four white Wings, the two formost
+  somewhat longer then the two hindermost, and the two shorter about half
+  an Inch long, each of which four Wings seem'd to consist of two small
+  long Feathers, very curiously tufted, or haired on each side, with purely
+  white, and exceedingly fine and small Haires, proportion'd to the stalks
+  or stems, out of which they grew, much like the tufts of a long
+  wing-feather of some Bird, and their stalks or stems were, like those,
+  bended backwards and downwards, as may be plainly seen by the draughts of
+  them in the Figure.</p>
+
+  <p>Observing one of these in my <i>Microscope</i>, I found, in the first
+  place, that all the Body, Legs, Horns and the Stalks of the Wings, were
+  covered over with various kinds of curious white Feathers, which did,
+  with handling or touching, easily rubb off and fly about, in so much that
+  looking on my Fingers, with which I had handled this Moth, and perceiving
+  on them little white specks, I found by my <i>Microscope</i>, that they
+  were several of the small Feathers of this little creature, that stuck up
+  and down in the <i>rugosities</i> of my Skin.</p>
+
+  <p>Next, I found that underneath these Feathers, the pretty Insect was
+  covered all over with a crusted Shell, like other of those Animals, but
+  with one much thinner and tenderer.</p>
+
+  <p>Thirdly, I found, as in Birds also is notable, it had differing and
+  appropriate kinds of Feathers, that covered several parts of its
+  body.</p>
+
+  <p>Fourthly, surveying the parts of its body, with a more accurate and
+  better Magnifying <i>Microscope</i>, I found that the tufts or haires of
+  its Wings were nothing else but a congeries, or thick set cluster of
+  small <i>vimina</i> or twiggs, resembling a small twigg of Birch, stript
+  or whitned, with which Brushes are usually made, to beat out or brush off
+  the dust from Cloth and Hangings. Every one of the twiggs or branches
+  that composed the Brush of the Feathers, appeared in this bigger
+  Magnifying Glass (of which EF which represents œ4 part of an Inch, is the
+  scale, as G is of the lesser, which is only 1/3) like the figure D. The
+  Feathers also that covered a part of his Body, and were interspersed
+  among the brush of his Wings, I found, in the bigger Magnifying Glass, of
+  the shape A, consisting of a stalk or stem in the middle, and a seeming
+  tuftedness or brushy part on each side. The Feathers that cover'd most
+  part of his Body and the stalk of his wings, were, in the same
+  <i>Microscope</i>, much of the figure B, appearing of the shape of a
+  small Feather, and seemed tufted: those which covered the Horns and small
+  parts of the Leggs, through the same <i>Microscope</i>, appear'd of the
+  shape C. Whether the tufts of any or all of these small Feathers,
+  consisted of such component particles as the Feathers of Birds, I much
+  doubt, because I find that Nature does not alwaies keep, or operate after
+  the same method, in smaller and bigger creatures. And of this, we have
+  particular Instances in the Wings of several creatures. For whereas, in
+  Birds of all kinds, it composes each of the Feathers of which its Wing
+  consists, of such an exceeding curious and most admirable and stupendious
+  texture, as I else where shew, in the Observations on a Feather; we find
+  it to alter its method quite, in the fabrick of the Wings of these minute
+  creatures, composing some of thin extended membranes
+  or skins, such as the Wings of Dragon-flys; in others, those skins are
+  all over-grown, or pretty thick bestuck, with short brisles, as in
+  Flesh-flies; in others, those filmes are covered, both on the upper and
+  under side, with small Feathers, plac'd almost like the tyles on a House,
+  and are curiously rang'd and adorn'd with most lively colours, as is
+  observable in Butter-flies, and several kinds of Moths; In others,
+  instead of their films, Nature has provided nothing, but a matter of half
+  a score stalks (if I well remember the number; for I have not lately met
+  with any of these flys, and did not, when I first observ'd them, take
+  sufficient notice of divers particulars) and each of these stalks, with a
+  few single branchings on each side, resembling much the branched
+  back-bone of a Herring or the like Fish, or a thin hair'd Peacocks
+  feather, the top or the eye being broken off. With a few of these on
+  either side (which it was able to shut up or expand at pleasure, much
+  like a Fann, or rather like the posture of the feathers in a wing,
+  whichly all one under another, when shut, and by the side of each other,
+  when expanded) this pretty little grey Moth (for such was the creature I
+  observ'd, thus wing'd) could very nimbly, and as it seem'd very easily
+  move its <i>corpuscle</i>, through the Air, from place to place. Other
+  Insects have their wings cas'd, or cover'd over, with certain hollow
+  shells, shap'd almost like those hollow Trayes, in which Butchers carry
+  meat, whose hollow sides being turn'd downwards, do not only secure their
+  folded wings from injury of the earth, in which most of those creatures
+  reside, but whilst they fly, serves as a help to sustain and bear them
+  up. And these are observable in <i>Scarabees</i> and a multitude of other
+  terrestrial <i>crustaceous</i> Insects; in which we may yet further
+  observe a particular providence of Nature.</p>
+
+  <p>Now in all these kinds of wings, we observe this particular, as a
+  thing most worthy remark; that where ever a wing consists of discontinued
+  parts, the Pores or <i>interstitia</i> between those parts are very
+  seldom, either much bigger, or much smaller, then these which we here
+  find between the particles of these brushes, so that it should seem to
+  intimate, that the parts of the Air are such, that they will not easily
+  or readily, if at all, pass through these Pores, so that they seem to be
+  strainers fine enough to hinder the particles of the Air (whether
+  hinder'd by their bulk, or by their <i>agitation</i>, <i>circulation</i>,
+  <i>rotation</i> or <i>undulation</i>, I shall not here determine) from
+  getting through them, and, by that means, serve the Animal as well, if
+  not better, then if they were little films. I say, if not better, because
+  I have observ'd that all those creatures, that have film'd wings, move
+  them aboundantly quicker and more strongly, such as all kind of Flies and
+  <i>Scarabees</i> and Batts, then such as have their wings covered with
+  feathers, as Butter-flies and Birds, or twiggs, as Moths, which have each
+  of them a much slower motion of their wings; That little ruggedness
+  perhaps of their wings helping them somewhat, by taking better hold of
+  the parts of the Air, or not suffering them so easily to pass by, any
+  other way then one.</p>
+
+  <p>But what ever be the reason of it, 'tis most evident, that the smooth
+  wing'd Insects, have the strongest Muscles or movent parts of their
+  wings, and the other much weaker; and this very Insect, we are now
+  describing, had a very small <i>thorax</i> or middle
+  part of his body, if compar'd to the length and number of his wings;
+  which therefore, as he mov'd them very slowly, so must he move them very
+  weakly. And this last propriety do we find somewhat observ'd also in
+  bigger kind of Flying creatures, Birds; so that we see that the Wisdom
+  and Providence of the All-wise Creator, is not less shewn in these small
+  despicable creatures, Flies and Moths, which we have branded with a name
+  of ignominy, calling them Vermine, then in those greater and more
+  remakable animate bodies, Birds.</p>
+
+  <p>I cannot here stand to add any thing about the nature of flying,
+  though, perhaps, on another occasion, I may say something on that
+  subject, it being such as may deserve a much more accurate examination
+  and scrutiny then it has hitherto met with; For to me there seems nothing
+  wanting to make a man able to fly, but what may be easily enough supply'd
+  from the Mechanicks hitherto known, save onely the want of strength,
+  which the Muscles of a man seem utterly uncapable of, by reason of their
+  smalness and texture, but how even strength also may be mechanically
+  made, and an artificial Muscle so contriv d, that thereby a man shall be
+  able to exert what strength he pleases, and to regulate it also to his
+  own mind, I may elsewhere endeavour to manifest.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLVII" id="obsXLVII">XLVII</a>. <i>Of the </i>Shepherd Spider<i>, or long legg'd
+</i>Spider<i>.</i></h3>
+
+  <p>The Carter, Shepherd Spider, or long-legg'd Spider, has, for two
+  particularities, very few similar creatures that I have met with, the
+  first, which is discoverable onely by the <i>Microscope</i>, and is in
+<span class="sidenote">
+<a href="images/scheme-31.png" target="_blank"><i>Schem.</i> 31.</a><br /><i>Fig.</i> 1. &amp; 2.
+</span>
+  the first and second <i>Figures</i> of the 31. <i>Scheme</i>, plainly
+  describ'd, is the curious contrivance of his eyes, of which (differing
+  from most other Spiders) he has onely two, and those plac'd upon the top
+  of a small pillar or hillock, rising out of the middle of the top of its
+  back, or rather the crown of its head, for they were fix'd on the very
+  top of this pillar (which is about the heighth of one of the transverse
+  Diameters of the eye, and look'd on in another posture, appear'd much of
+  the shape, BCD.) The two eyes, BB, were placed back to back, with the
+  transparent parts, or the pupils, looking towards either side, but
+  somewhat more forward then backwards. C was the column or neck on which
+  they stood, and D the crown of the head out of which that neck
+  sprung.</p>
+
+  <p>These eyes, to appearance, seem'd to be of the very same structure
+  with that of larger <i>binocular</i> creatures, seeming to have a very
+  smooth and very protuberant <i>Cornea</i>, and in the midst of it to
+  have a very black pupil, incompassed about with a kind of grey
+  <i>Iris</i>, as appears by the <i>Figure</i>; whether it were able to
+  move these eyes to and fro, I have not observ'd, but 'tis not very likely
+  he should, the pillar or neck C, seeming to be cover'd and stiffen'd with
+  a crusty shell; but Nature, in probability, has supply'd
+  that defect, by making the <i>Cornea</i> so very protuberant, and setting
+  it so cleer above the shadowing or obstructing of its prospect by the
+  body, that 'tis likely each eye may perceive, though not see distinctly,
+  almost a <i>Hemisphere</i>, whence having so small and round a body
+  plac'd upon such long leggs, it is quickly able so to wind, and turn it,
+  as to see any thing distinct. This creature, as do all other Spiders I
+  have yet examin'd, does very much differ from most other Insects in the
+  Figure of its eyes; for I cannot, with my best <i>Microscope</i>,
+  discover its eyes to be any ways knobb'd or pearl'd like those of other
+  Insects.</p>
+
+  <p>The second Peculiarity which is obvious to the eye, is also very
+  remarkable, and that is the prodigious length of its leggs, in proportion
+  to its small round body, each legg of this I drew, being above sixteen
+  times the length of its whole body, and there are some which have them
+  yet longer, and others that seem of the same kind, that have them a great
+  deal shorter; the eight leggs are each of them jointed, just like those
+  of a Crab, but every of the parts are spun out prodigiously longer in
+  proportion; each of these leggs are terminated in a small case or shell,
+  shap'd almost like that of a Musle-shell, as is evident in the third
+<span class="sidenote">
+<a href="images/scheme-31.png" target="_blank"><i>Schem.</i> 31.</a><br /><i>Fig.</i> 3.
+</span>
+  <i>Figure</i> of the same <i>Scheme</i> (that represents the appearance
+  ot the under part or belly of the creature) by the shape of the
+  protuberant <i>conical</i> body, IIII, <i>&amp;c.</i> These are as 'twere
+  plac'd or fasten'd on to the protuberant body of the Insect, which is to
+  be suppos'd very high at M, making a kind of blunt cone whereof M is to
+  be suppos'd the <i>Apex</i>, about which greater cone of the body, the
+  smaller cones of the leggs are plac'd, each of them almost reaching to
+  the top in so admirable a manner, as does not a little manifest the
+  wisdom of Nature in the contrivance; for these long Leavers (as I may so
+  call them) of the legs, having not the advantage of a long end on the
+  other side of the <i>hypomochlion</i> or centers on which the parts of
+  the leggs move, must necessarily require a vast strength to move them,
+  and keep the body ballanc'd and suspended, in so much, that if we should
+  suppose a man's body suspended by such a contrivance, an hundred and
+  fifty times the strength of a man would not keep the body from falling on
+  the breast. To supply therefore each of these leggs with its proper
+  strength, Nature has allow'd to each a large Chest or Cell, in which is
+  included a very large and strong Muscle, and thereby this little Animal
+  is not onely able to suspend its body upon less then these eight, but to
+  move it very swiftly over the tops of grass and leaves.</p>
+
+  <p>Nor are these eight leggs so prodigiously long, but the ninth, and
+  tenth, which are the two claws, KK, are as short, and serve in steed of a
+  <i>proboscis</i>, for those seem'd very little longer then his mouth;
+  each of them had three parts, but very short, the joints KK, which
+  represented the third, being longer then both the other. This creature,
+  seems (which I have several times with pleasure observ'd) to throw its
+  body upon the prey, insteed of its hands, not unlike a hunting Spider,
+  which leaps like a Cat at a Mouse. The whole Fabrick was a very pretty
+  one, and could I have dissected it, I doubt not but I should have found
+  as many singularities within it as without, perhaps, for the most part,
+  not unlike the parts of a Crab, which this little
+  creature does in many things, very much resemble; the curiosity of whose
+  contrivance, I have in another place examin'd. I omit the description of
+  the horns, AA, of the mouth, LL, which seem'd like that of a Crab; the
+  speckledness of his shell, which proceeded from a kind of feathers or
+  hairs, and the hairiness of his leggs, his large <i>thorax</i> and little
+  belly, and the like, they being manifested by the Figure; and shall onely
+  take notice that the three parts of the body, namely, the head, breast,
+  and belly, are in this creature strangely confus'd, so that 'tis
+  difficult to determine which is which, as they are also in a Crab; and
+  indeed, this seems to be nothing else, but an Air-crab, being made more
+  light and nimble, proportionable to the <i>medium</i> wherin it resides;
+  and as Air seems to have but one thousandth part of the body of Water, so
+  does this Spider seem not to be a thousandth part of the bulk of a
+  Crab.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLVIII" id="obsXLVIII">XLVIII</a>. <i>Of the hunting </i>Spider<i>, and several other sorts
+of </i>Spiders<i>.</i></h3>
+
+  <p>The hunting Spider is a small grey Spider, prettily bespeck'd with
+  black spots all over its body, which the <i>Microscope</i> discovers to
+  be a kind of feathers like those on Butterflies wings, or the body of the
+  white Moth I lately describ'd. Its gate is very nimble by fits, sometimes
+  running, and sometimes leaping, like a Grashopper almost, then standing
+  still, and setting it self on its hinder leggs, it will very nimbly turn
+  its body, and look round it self every way: It has six very conspicuous
+  eyes, two looking directly forwards, plac'd just before; two other, on
+  either side of those, looking forward and side-ways; and two other about
+  the middle of the top of its back or head, which look backwards and
+  side-wards; these seem'd to be the biggest. The surface of them all was
+  very black, sphærical, purely polish'd, reflecting a very cleer and
+  distinct Image of all the ambient objects, such as a window, a man's
+  hand, a white Paper, or the like. Some other properties of this Spider,
+  observ'd by the most accomplish'd Mr. <i>Evelyn</i>, in his travels in
+  <i>Italy</i>, are most emphatically set forth in the History hereunto
+  annexed, which he was pleas'd upon my desire to send me in writing.</p>
+
+<blockquote>
+  <p>Of all the sorts of Insects, there is none has afforded me more
+  divertisements then the <i>Venatores</i>, which are a sort of
+  <i>Lupi</i>, that have their Denns in the rugged walls, and crevices of
+  our houses; a small brown and delicately spotted kind of Spiders, whose
+  hinder leggs are longer then the rest.</p>
+
+  <p>Such I did frequently observe at <i>Rome</i>, which espying a Fly at
+  three or four yards distance, upon the Balcony (where I stood)
+  would not make directly to her, but craul
+  under the Rail, till being arriv'd to the <i>Antipodes</i>, it would
+  steal up, seldom missing its aim; but if it chanced to want any thing of
+  being perfectly opposite, would at first peep, immediatly slide down
+  again, till taking better notice, it would come the next time exactly
+  upon the Fly's back: But, if this hapn'd not to be within a competent
+  leap, then would this Insect move so softly, as the very shadow of the
+  Gnomon seem'd not to be more imperceptible, unless the Fly mov'd; and
+  then would the Spider move also in the same proportion, keeping that just
+  time with her motion, as if the same Soul had animated both those little
+  bodies; and whether it were forwards, backwards, or to either side,
+  without at all turning her body, like a well mannag'd Horse: But, if the
+  capricious Fly took wing, and pitch'd upon another place behind our
+  Huntress, then would the Spider whirle its body so nimbly about, as
+  nothing could be imagin'd more swift; by which means, she always kept the
+  head towards her prey, though to appearance, as immovable, as if it had
+  been a Nail driven into the Wood, till by that indiscernable progress
+  (being arriv'd within the sphere of her reach) she made a fatal leap
+  (swift as Lightning) upon the Fly, catching him in the pole, where she
+  never quitted hold till her belly was full, and then carried the
+  remainder home. I have beheld them instructing their young ones, how to
+  hunt, which they would sometimes discipline for not well observing; but,
+  when any of the old ones did (as sometimes) miss a leap, they would run
+  out of the field, and hide them in their crannies, as asham'd, and haply
+  not be seen abroad for four or five hours after; for so long have I
+  watched the nature of this strange Insect, the contemplation of whose so
+  wonderfull sagacity and address has amaz'd me; nor do I find in any chase
+  whatsoever, more cunning and Stratagem observ'd: I have found some of
+  these Spiders in my Garden, when the weather (towards the Spring)
+  is very hot, but they are nothing so eager
+  of hunting as they are in <i>Italy</i>.</p>
+
+</blockquote>
+
+  <p>There are multitudes of other sorts of Spiders, whose eyes, and most
+  other parts and properties, are so exceedingly different both from those
+  I have describ'd, and from one another, that it would be almost endless,
+  at least too long for my present Essay, to describe them, as some with
+  six eyes, plac'd in quite another order; others with eight eyes; others
+  with fewer, and some with more. They all seem to be creatures of prey,
+  and to feed on other small Insects, but their ways of catching them seem
+  very differing: the Shepherd Spider by running on his prey; the Hunting
+  Spider by leaping on it, other sorts weave Nets, or Cobwebs, whereby they
+  ensnare them, Nature having both fitted them with materials and tools,
+  and taught them how to work and weave their Nets, and to lie perdue, and
+  to watch diligently to run on any Fly, as soon as ever entangled.</p>
+
+  <p>Their thread or web seems to be spun out of some viscous kind of
+  excrement, lying in their belly, which, though soft when drawn out, is,
+  presently by reason of its smallness, hardned and dried by the ambient
+  Air. Examining several of which with my <i>Microscope</i>, I found them
+  to appear much like white Hors-hair, or some such transparent horny
+  substance, and to be of very differing magnitudes; some appearing as bigg
+  as a Pigg's brisle, others equal to a Horss-hair; other no bigger then a
+  man's hair; others yet smaller and finer. I observ'd further, that the
+  radiating chords of the web were much bigger, and smoother then those
+  that were woven round, which seem'd smaller, and all over knotted or
+  pearl'd, with small transparent Globules, not unlike small Crystal Beads
+  or seed Pearls, thin strung on a Clew of Silk; which, whether they were
+  so spun by the Spider, or by the adventitious moisture of a fogg (which I
+  have observ'd to cover all these filaments with such Crystalline Beads) I
+  will not now dispute.</p>
+
+  <p>These threads were some of them so small, that I could very plainly,
+  with the <i>Microscope</i>, discover the same consecutions of colours as
+  in a <i>Prisme</i>, and they seem'd to proceed from the same cause with
+  those colours which I have already describ'd in thin plated bodies.</p>
+
+  <p>Much resembling a Cobweb, or a confus'd lock of these Cylinders, is a
+  certain white substance which, after a fogg, may be observ'd to fly up
+  and down the Air; catching several of these, and examining them with my
+  <i>Microscope</i>, I found them to be much of the same form, looking most
+  like to a flake of Worsted prepar'd to be spun, though by what means they
+  should be generated, or produc'd, is not easily imagined: they were of
+  the same weight, or very little heavier then the Air; and 'tis not
+  unlikely, but that those great white clouds, that appear all the Summer
+  time, may be of the same substance.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsXLIX" id="obsXLIX">XLIX</a>. <i>Of an </i>Ant<i> or </i>Pismire<i>.</i></h3>
+
+  <p>This was a creature, more troublesom to be drawn, then any of the
+  rest, for I could not, for a good while, think of a way to make it suffer
+  its body to ly quiet in a natural posture; but whil'st it was alive, if
+  its feet were fetter'd in Wax or Glew, it would so twist and wind its
+  body, that I could not any wayes get a good view of it; and if I killed
+  it, its body was so little, that I did often spoile the shape of it,
+  before I could throughly view it: for this is the nature of these minute
+  Bodies, that as soon, almost, as ever their life is destroy'd, their
+  parts immediately shrivel, and lose their beauty; and so is it also with
+  small Plants, as I instanced before, in the description of Moss. And
+  thence also is the reason of the variations in the beards of wild Oats,
+  and in those of Musk-grass seed, that their bodies, being exceeding
+  small, those small variations which are made in the surfaces of all
+  bodies, almost upon every change of Air, especially if the body be
+  porous, do here become sensible, where the whole body is so small, that
+  it is almost nothing but surface; for as in vegetable substances, I see
+  no great reason to think, that the moisture of the Aire (that, sticking
+  to a wreath'd beard, does make it untwist) should evaporate, or exhale
+  away, any faster then the moisture of other bodies, but rather that the
+  avolation from, or access of moisture to, the surfaces of bodies being
+  much the same, those bodies become most sensible of it, which have the
+  least proportion of body to their surface. So is it also with Animal
+  substances; the dead body of an Ant, or such little creature, does almost
+  instantly shrivel and dry, and your object shall be quite another thing,
+  before you can half delineate it, which proceeds not from the
+  extraordinary exhalation, but from the small proportion of body and
+  juices, to the usual drying of bodies in the Air, especially if warm. For
+  which inconvenience, where I could not otherwise remove it, I thought of
+  this expedient.</p>
+
+  <p>I took the creature, I had design'd to delineate, and put it into a
+  drop of very well rectified spirit of Wine, this I found would presently
+  dispatch, as it were, the Animal, and being taken out of it, and lay'd on
+  a paper, the spirit of Wine would immediately fly away, and leave the
+  Animal dry, in its natural posture, or at least, in a constitution, that
+  it might easily with a pin be plac'd, in what posture you desired to draw
+  it, and the limbs would so remain, without either moving, or shriveling.
+  And thus I dealt with this Ant, which I have here delineated, which was
+  one of many, of a very large kind, that inhabited under the Roots of a
+  Tree, from whence they would sally out in great parties, and make most
+  grievous havock of the Flowers and Fruits, in the ambient Garden, and
+  return back again very expertly, by the same wayes and paths they
+  went.</p>
+
+  <p>It was more then half the bigness of an Earwig, of a dark brown, or
+  reddish colour, with long legs, on the hinder of which it would stand
+  up, and raise its head as high as it could
+  above the ground, that it might stare the further about it, just after
+  the same manner as I have also observ'd a hunting Spider to do: and
+  putting my finger towards them, they have at first all run towards it,
+  till almost at it; and then they would stand round about it, at a certain
+  distance, and smell, as it were, and consider whether they should any of
+  them venture any further, till one more bold then the rest venturing to
+  climb it, all the rest, if I would have suffered them, would have
+  immediately followed: many such other seemingly rational actions I have
+  observ'd in this little Vermine with much pleasure, which would be too
+  long to be here related; those that desire more of them may satisfie
+  their curiosity in <i>Ligons</i> History of the <i>Barbadoes</i>.</p>
+
+  <p>Having insnar'd several of these into a small Box, I made choice of
+  the tallest grown among them, and separating it from the rest, I gave it
+  a Gill of Brandy, or Spirit of Wine, which after a while e'en knock'd him
+  down dead drunk, so that he became moveless, though at first putting in
+  he struggled for a pretty while very much, till at last, certain bubbles
+  issuing out of its mouth, it ceased to move; this (because I had before
+  found them quickly to recover again, if they were taken out presently) I
+  suffered to lye above an hour in the Spirit; and after I had taken it
+  out, and put its body and legs into a natural posture, remained moveless
+  about an hour; but then, upon a sudden, as if it had been awaken out of a
+  drunken sleep, it suddenly reviv'd and ran away; being caught, and serv'd
+  as before, he for a while continued struggling and striving, till at last
+  there issued several bubbles out of its mouth, and then, <i>tanquam
+  animam expirasset</i>, he remained moveless for a good while; but at
+  length again recovering, it was again redipt, and suffered to lye some
+  hours in the Spirit; notwithstanding which, after it had layen dry some
+  three or four hours, it again recovered life and motion: Which kind of
+  Experiments, if prosecuted, which they highly deserve, seem to me of no
+  inconsiderable use towards the invention of the <i>Latent Scheme</i>, (as
+  the Noble <i>Verulam</i> calls it) or the hidden, unknown Texture of
+  Bodies.</p>
+
+<span class="sidenote">
+<a href="images/scheme-32.png" target="_blank"><i>Schem.</i> 32.</a>
+</span>
+  <p>Of what Figure this Creature appear'd through the <i>Microscope</i>,
+  the 32. <i>Scheme</i> (though not so carefully graven as it ought) will
+  represent to the eye, namely, That it had a large head AA, at the upper
+  end of which were two protuberant eyes, pearl'd like those of a Fly, but
+  smaller BB; out of the Nose, or foremost part, issued two horns CC, of a
+  shape sufficiently differing from those of a blew Fly, though indeed they
+  seem to be both the same kind of Organ, and to serve for a kind of
+  smelling; beyond these were two indented jaws DD, which he open'd
+  side-wayes, and was able to gape them asunder very wide; and the ends of
+  them being armed with teeth, which meeting went between each other, it
+  was able to grasp and hold a heavy body, three or four times the bulk and
+  weight of its own body: It had only six legs, shap'd like those of a Fly,
+  which, as I shewed before, is an Argument that it is a winged Insect, and
+  though I could not perceive any sign of them in the middle part of its
+  body (which seem'd to consist of three joints or pieces
+  EFG, out of which sprung two legs), yet 'tis known that there are of them
+  that have long wings, and fly up and down in the air.</p>
+
+  <p>The third and last part of its body III was bigger and larger then the
+  other two, unto which it was joyn'd by a very small middle, and had a
+  kind of loose shell, or another distinct part of its body H, which seem'd
+  to be interpos'd, and to keep the <i>thorax</i> and belly from
+  touching.</p>
+
+  <p>The whole body was cas'd over with a very strong armour, and the belly
+  III was covered likewise with multitudes of small white shining brisles;
+  the legs, horns, head, and middle parts of its body were bestuck with
+  hairs also, but smaller and darker.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsL" id="obsL">L</a>. <i>Of the wandring </i>Mite<i>.</i></h3>
+
+  <p>In <i>September</i> and <i>October, 1661.</i> I observ'd in
+  <i>Oxford</i> several of these little pretty Creatures to wander to and
+  fro, and often to travel over the plains of my Window. And in
+  <i>September</i> and <i>October, 1663.</i> I observ'd likewise several of
+  these very same Creatures traversing a window at <i>London</i>, and
+  looking without the window upon the subjacent wall, I found whole flocks
+  of the same kind running to and fro among the small groves and thickets
+  of green moss, and upon the curiously spreading vegetable blew or yellow
+  moss, which is a kind of a Mushrome or Jews-ear.</p>
+
+  <p>These Creatures to the naked eye seemed to be a kind of black Mite,
+  but much nimbler and stronger then the ordinary Cheese-Mites; but
+  examining them in a <i>Microscope</i>, I found them to be a very fine
+<span class="sidenote">
+<a href="images/scheme-33.png" target="_blank"><i>Schem.</i> 33.</a><br /><i>Fig.</i> 1.
+</span>
+  crusted or shell'd Insect, much like that represented in the first Figure
+  of the three and thirtieth <i>Scheme</i>, with a protuberant oval shell
+  A, indented or pitted with an abundance of small pits, all covered over
+  with little white brisles, whose points all directed backwards.</p>
+
+  <p>It had eight legs, each of them provided with a very sharp tallon, or
+  claw at the end, which this little Animal, in its going, fastned into the
+  pores of the body over which it went. Each of these legs were bestuck in
+  every joynt of them with multitudes of small hairs, or (if we respect the
+  proportion they bore to the bigness of the leg) turnpikes, all pointing
+  towards the claws.</p>
+
+  <p>The <i>Thorax</i>, or middle parts of the body of this Creature, was
+  exceeding small, in respect both of the head and belly, it being nothing
+  but that part which was covered by the two shells BB, though it seem'd to
+  grow thicker underneath: And indeed, if we consider the great variety
+  Nature uses in proportioning the three parts of the body, (the
+  <i>Head</i>, <i>Thorax</i>, and <i>Belly</i>) we shall not wonder at the
+  small proportion of this <i>Thorax</i>, nor at the vaster bulk of the
+  belly, for could we exactly anatomise this little Creature, and observe
+  the particular designs of each part, we should doubtless, as we do in all
+  her more manageable and tractable fabricks, find
+  much more reason to admire the excellency of her contrivance and
+  workmanship, then to wonder, it was not made otherwise.</p>
+
+  <p>The head of this little Insect was shap'd somewhat like a Mite's, that
+  is, it had a long snout, in the manner of a Hogs, with a knobbed ridge
+  running along the middle of it, which was bestuck on either side with
+  many small brisles, all pointing forward, and two very large pikes or
+  horns, which rose from the top of the head, just over each eye, and
+  pointed forward also. It had two pretty large black eyes on either side
+  of the head EE, from one of which I could see a very bright reflection of
+  the window, which made me ghess, that the <i>Cornea</i> of it was smooth,
+  like those of bigger Insects. Its motion was pretty quick and strong, it
+  being able very easily to tumble a stone or clod four times as big as its
+  whole body.</p>
+
+  <p>At the same time and place, and divers times since, I have observed
+  with my <i>Microscope</i>, another little Insect, which, though I have
+  not annexed the picture of, may be worth noting, for its exceeding
+  nimbleness as well as smalness; it was as small as a Mite, with a body
+  deep and ridged, almost like a Flea; it had eight blood-red legs, not
+  very long, but slender; and two horns or feelers before. Its motion was
+  so exceeding quick, that I have often lost sight of one I have observed
+  with my naked eye; and though, when it was not frighted, I was able to
+  follow the motions of some with my <i>Microscope</i>; yet if it were
+  never so little startled, it posted away with such speed, and turn'd and
+  winded it self so quick, that I should presently lose sight of it.</p>
+
+  <p>When I first observ'd the former of these Insects, or Mites, I began
+  to conjecture, that certainly I had found out the vagabond Parents of
+  those Mites we find in Cheeses, Meal, Corn, Seeds, musty Barrels, musty
+  Leather, &amp;c. these little Creatures, wandring to and fro every
+  whither, might perhaps, as they were invited hither and thither by the
+  musty steams of several putrifying bodies, make their invasions upon
+  those new and pleasing territories, and there spending the remainder of
+  their life, which might be perhaps a day, or thereabouts, in very
+  plentiful and riotous living, might leave their off-spring behind them,
+  which by the change of the soil and Country they now inhabite, might be
+  quite alter'd from the hew of their <i>primogenitors</i>, and, like
+  <i>Mores</i> translated into Northern <i>European</i> Climates, after a
+  little time, change both their skin and shape. And this seems yet more
+  probable in these Insects, because that the soil or body they inhabit,
+  seems to be almost half their parent, for it not only hatches and brings
+  those little eggs, or seminal principles, to perfection, but seems to
+  augment and nourish them also before they are hatch'd or shaped; for it
+  is obvious enough to be observ'd, that the eggs of many other Insects,
+  and particularly of Mites, are increas'd in bulk after they are laid out
+  of the bodies of the Insects, and plump'd sometimes into many times their
+  former bigness, so that the bodies they are laid in being, as it were,
+  half their mothers, we shall not wonder that it should have such an
+  active power to change their forms. We find by relations
+  how much the <i>Negro</i> Women do besmeer the of-spring of the
+  <i>Spaniard</i>, bringing forth neither white-skinn'd nor black, but
+  tawny hided <i>Mulattos</i>.</p>
+
+  <p>Now, though I propound this as probable, I have not yet been so farr
+  certify'd by Observations as to conclude any thing, either positively or
+  negatively, concerning it. Perhaps, some more lucky diligence may please
+  the curious Inquirer with the discovery of this, to be a truth, which I
+  now conjecture, and may thereby give him a satisfactory account of the
+  cause of those creatures, whose original seems yet to obscure, and may
+  give him cause to believe, that many other animate beings, that seem also
+  to be the mere product of putrifaction, may be innobled with a Pedigree
+  as ancient as the first creation, and farr exceed the greatest beings in
+  their numerous Genealogies. But on the other side, if it should be found
+  that these, or any other animate body, have no immediate similar Parent,
+  I have in another place set down a conjectural <i>Hypothesis</i> whereby
+  those <i>Phænomena</i> may likely enough be solv'd, wherein the infinite
+  wisdom and providence of the Creator is no less rare and wonderfull.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLI" id="obsLI">LI</a>. <i>Of the </i>Crab-like<i> Insect.</i></h3>
+
+  <p>Reading one day in <i>Septemb.</i> I chanced to observe a very smal
+  creature creep over the Book I was reading, very slowly; having a
+  <i>Microscope</i> by me, I observ'd it to be a creature of a very unusual
+<span class="sidenote">
+<a href="images/scheme-33.png" target="_blank"><i>Schem.</i> 33.</a><br /><i>Fig.</i> 2.
+</span>
+  form, and that not less notable; such as is describ'd in the second
+  <i>Figure</i> of the 33. <i>Scheme</i>. It was about the bigness of a
+  large Mite, or somewhat longer, it had ten legs, eight of which, AAAA,
+  were topt with very sharp claws, and were those upon which he walk'd,
+  seeming shap'd much like those of a Crab, which in many other things also
+  this little creature resembled; for the two other claws, BB, which were
+  the formost of all the ten, and seem'd to grow out of his head, like the
+  horns of other Animals, were exactly form'd in the manner of Crabs or
+  Lobsters claws, for they were shap'd and jointed much like those
+  represented in the <i>Scheme</i> and the ends of them were furnish'd with
+  a pair of claws or pincers, CC, which this little animal did open and
+  shut at pleasure: It seem'd to make use of those two horns or claws both
+  for feelers and holders; for in its motion it carried these aloft
+  extended before, moving them to and fro, just as a man blindfolded would
+  do his hands when he is fearfull of running against a wall, and if I put
+  a hair to it, it would readily take hold of it with these claws, and seem
+  to hold it fast. Now, though these horns seem'd to serve him for two
+  uses, namely, for feeling and holding; yet he seem'd neither blind,
+  having two small black spots, DD, which by the make of them, and the
+  bright reflection from them seem'd to be his eyes, nor did it want other
+  hands, having another pair of claws, EE, very neer plac'd to its mouth,
+  and seem'd adjoining to it.</p>
+
+  <p>The whole body was cased over with armour-shells, as is usuall in all
+  those kinds of <i>crustaceous</i>
+  creatures, especially about their bellies, and seem'd of three kinds, the
+  head F seem'd cover'd with a kind of scaly shell, the <i>thorax</i> with
+  two smooth shells, or Rings, GG, and the belly with eight knobb'd ones. I
+  could not certainly find whether it had under these last shells any
+  wings, but I suspect the contrary; for I have not found any wing'd Insect
+  with eight leggs, two of those leggs being always converted into wings,
+  and, for the most part, those that have but six, have wings.</p>
+
+  <p>This creature, though I could never meet with more then one of them,
+  and so could not make so many examinations of it as otherwise I would, I
+  did notwithstanding, by reason of the great curiosity that appear'd to me
+  in its shape, delineate it, to shew that, in all likelihood, Nature had
+  crouded together into this very minute Insect, as many, and as excellent
+  contrivances, as into the body of a very large Crab, which exceeds it in
+  bulk, perhaps, some Millions of times; for as to all the apparent parts,
+  there is a greater rather then a less multiplicity of parts, each legg
+  has as many parts, and as many joints as a Crabs, nay, and as many hairs
+  or brisles; and the like may be in all the other visible parts; and 'tis
+  very likely, that the internal curiosities are not less excellent: It
+  being a general rule in Nature's proceedings, that where she begins to
+  display any excellency, if the subject be further search'd into, it will
+  manifest, that there is not less curiosity in those parts which our
+  single eye cannot reach, then in those which are more obvious.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLII" id="obsLII">LII</a>. <i>Of the small Silver-colour'd </i>Book-worm<i>.</i></h3>
+
+  <p>As among greater Animals there are many that are scaled, both for
+  ornament and defence, so are there not wanting such also among the lesser
+  bodies of Insects, whereof this little creature gives us an Instance. It
+  is a small white Silver-shining Worm or Moth, which I found much
+  conversant among Books and Papers, and is suppos'd to be that which
+  corrodes and eats holes through the leaves and covers; it appears to the
+  naked eye, a small glittering Pearl-colour'd Moth, which upon the
+  removing of Books and Papers in the Summer, is often observ'd very nimbly
+  to scud, and pack away to some lurking cranney, where it may the better
+  protect itself from any appearing dangers. Its head appears bigg and
+  blunt, and its body tapers from it towads the tail, smaller and smaller,
+  being shap'd almost like a Carret.</p>
+
+<span class="sidenote">
+<a href="images/scheme-33.png" target="_blank"><i>Schem.</i> 33.</a><br /><i>Fig.</i> 3.
+</span>
+  <p>This the <i>Microscopical</i> appearance will more plainly manifest,
+  which exhibits, in the third <i>Figure</i> of the 33. <i>Scheme</i>, a
+  conical body, divided into fourteen several partitions, being the
+  appearance of so many several shels, or shields that cover the whole
+  body, every of these shells are again cover'd or tiled over with a
+  multitude of thin transparent scales, which, from the multiplicity of
+  their reflecting surfaces, make the whole Animal appear of a perfect
+  Pearl-colour.</p>
+
+  <p>Which, by the way, may hint us the reason of that so much admired
+  appearance of those so highly esteem'd bodies, as also of the like in
+  mother of Pearl-shells, and in multitudes of other shelly Sea-substances;
+  for they each of them consisting of an infinite number of very thin
+  shells or laminated orbiculations, cause such multitudes of reflections,
+  that the compositions of them together with the reflections of others
+  that are so thin as to afford colours (of which I elsewhere give the
+  reason) gives a very pleasant reflection of light. And that this is the
+  true cause, seems likely, first, because all those so appearing bodies
+  are compounded of multitudes of plated substances. And next that, by
+  ordering any trasparent substance after this manner, the like
+  <i>Phænomena</i> may be produc'd; this will be made very obvious by the
+  blowing of Glass into exceeding thin shells, and then breaking them into
+  scales, which any lamp-worker will presently do; for a good quantity of
+  these scales, laid in a heap together, have much the same resemblance of
+  Pearls. Another way, not less instructive and pleasant, is a way which I
+  have several times done, which is by working and tossing, as 'twere, a
+  parcel of pure crystalline glass whilst it is kept glowing hot in the
+  blown flame of a Lamp, for, by that means, that purely transparent body
+  will be so divided into an infinite number of plates, or small strings,
+  with interpos'd aerial plates and <i>fibres</i>, that from the
+  multiplicity of the reflections from each of those internal surfaces, it
+  may be drawn out into curious Pearl-like or Silver wire, which though
+  small, will yet be opacous; the same thing I have done with a composition
+  of red <i>Colophon</i> and <i>Turpentine</i>, and a little Bee's Wax, and
+  may be done likewise with Birdlime, and such like glutinous and
+  transparent bodies: But to return to our description.</p>
+
+  <p>The small blunt head of this Insect was furnish'd on either side of it
+  with a cluster of eyes, each of which seem'd to contain but a very few,
+  in comparison of what I had observ'd the clusters of other Insects to
+  abound with; each of these clusters were beset with a row of small
+  brisles, much like the <i>cilia</i> or hairs on the eye-lids, and,
+  perhaps, they serv'd for the same purpose. It had two long horns before,
+  which were streight, and tapering towards the top, curiously ring'd or
+  knobb'd, and brisled much like the Marsh Weed, call'd Horse-tail, or
+  Cats-tail, having at each knot a fring'd Girdle, as I may so call it, of
+  smaller hairs, and several bigger and larger brisles, here and there
+  dispers'd among them: besides these, it had two shorter horns, or
+  feelers, which were knotted and fring'd, just as the former, but wanted
+  brisles, and were blunt at the ends; the hinder part of the creature was
+  terminated with three tails, in every particular resembling the two
+  longer horns that grew out of the head: The leggs of it were scal'd and
+  hair'd much like the rest, but are not express'd in this <i>Figure</i>,
+  the Moth being intangled all in Glew, and so the leggs of this appear'd
+  not through the Glass which looked perpendicularly upon the back.</p>
+
+  <p>This Animal probably feeds upon the Paper and covers of Books, and
+  perforates in them several small round holes, finding, perhaps, a
+  convenient nourishment in those hulks of Hemp and Flax, which have pass'd
+  through so many scourings, washings,
+  dressings and dryings, as the parts of old Paper must necessarily have
+  suffer'd; the digestive faculty, it seems, of these little creatures
+  being able yet further to work upon those stubborn parts, and reduce them
+  into another form.</p>
+
+  <p>And indeed, when I consider what a heap of Saw-dust or chips this
+  little creature (which is one of the teeth of Time) conveys into its
+  intrals, I cannot chuse but remember and admire the excellent contrivance
+  of Nature, in placing in Animals such a fire, as is continually nourished
+  and supply'd by the materials convey'd into the stomach, and
+  <i>fomented</i> by the bellows of the lungs; and in so contriving the
+  most admirable fabrick of Animals, as to make the very spending and
+  wasting of that fire, to be instrumental to the procuring and collecting
+  more materials to augment and cherish it self, which indeed seems to be
+  the principal end of all the contrivances observable in bruit
+  Animals.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLIII" id="obsLIII">LIII</a>. <i>Of a </i>Flea<i>.</i></h3>
+
+  <p>The strength and beauty of this small creature, had it no other
+  relation at all to man, would deserve a description.</p>
+
+  <p>For its strength, the <i>Microscope</i> is able to make no greater
+  discoveries of it then the naked eye, but onely the curious contrivance
+  of its leggs and joints, for the exerting that strength, is very plainly
+  manifested, such as no other creature, I have yet observ'd, has any thing
+  like it; for the joints of it are so adapted, that he can, as 'twere,
+  fold them short one within another, and suddenly stretch, or spring them
+<span class="sidenote">
+<a href="images/scheme-34.png" target="_blank"><i>Schem.</i> 34.</a>
+</span>
+  out to their whole length, that is, of the fore-leggs, the part A, of the
+  34. <i>Scheme</i>, lies within B, and B within C, parallel to, or side by
+  side each other; but the parts of the two next, lie quite contrary, that
+  is, D without E, and E without F, but parallel also; but the parts of the
+  hinder leggs, G, H and I, bend one within another, like the parts of a
+  double jointed Ruler, or like the foot, legg and thigh of a man; these
+  six leggs he clitches up altogether, and when he leaps, springs them all
+  out, and thereby exerts his whole strength at once.</p>
+
+  <p>But, as for the beauty of it, the <i>Microscope</i> manifests it to be
+  all over adorn'd with a curiously polish'd suit of <i>sable</i> Armour,
+  neatly jointed, and beset with multitudes of sharp pinns, shap'd almost
+  like Porcupine's Quills, or bright conical Steel-bodkins; the head is on
+  either side beautify'd with a quick and round black eye K, behind each of
+  which also appears a small cavity, L, in which he seems to move to and
+  fro a certain thin film beset with many small transparent hairs, which
+  probably may be his ears; in the forepart of his head, between the two
+  fore-leggs, he has two small long jointed feelers, or rather smellers,
+  MM, which have four joints, and are hairy, like those of several other
+  creatures; between these, it has a small <i>proboscis</i>, or
+  <i>probe</i>, NNO, that seems to consist of a tube NN,
+  and a tongue or sucker O, which I have perceiv'd him to slip in and out.
+  Besides these, it has also two chaps or biters PP, which are somewhat
+  like those of an Ant, but I could not perceive them tooth'd; these were
+  shap'd very like the blades of a pair of round top'd Scizers, and were
+  opened and shut just after the same manner; with these Instruments does
+  this little busie Creature bite and pierce the skin, and suck out the
+  blood of an Animal, leaving the skin inflamed with a small round red
+  spot. These parts are very difficult to be discovered, because, for the
+  most part, they lye covered between the fore-legs. There are many other
+  particulars, which, being more obvious, and affording no great matter of
+  information, I shall pass by, and refer the Reader to the Figure.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLIV" id="obsLIV">LIV</a>. <i>Of a Louse.</i></h3>
+
+  <p>This is a Creature so officious, that 'twill be known to every one at
+  one time or other, so busie, and so impudent, that it will be intruding
+  it self in every ones company, and so proud and aspiring withall, that it
+  fears not to trample on the best, and affects nothing so much as a Crown;
+  feeds and lives very high, and that makes it so saucy, as to pull any one
+  by the ears that comes in its way, and will never be quiet till it has
+  drawn blood: it is troubled at nothing so much as at a man that scratches
+  his head, as knowing that man is plotting and contriving some mischief
+  against it, and that makes it oftentime sculk into some meaner and lower
+  place, and run behind a mans back, though it go very much against the
+  hair; which ill conditions of it having made it better known then
+  trusted, would exempt me from making any further description of it, did
+  not my faithful <i>Mercury</i>, my <i>Microscope</i>, bring me other
+  information of it. For this has discovered to me, by means of a very
+  bright light cast on it, that it is a Creature of a very odd shape; it
+<span class="sidenote">
+<a href="images/scheme-35.png" target="_blank"><i>Schem.</i> 35.</a>
+</span>
+  has a head shap'd like that exprest in 35. <i>Scheme</i> marked with A,
+  which seems almost Conical, but is a little flatted on the upper and
+  under sides, at the biggest part of which, on either side behind the head
+  (as it were, being the place where other Creatures ears stand) are placed
+  its two black shining goggle eyes BB, looking backwards, and fenced round
+  with several small <i>cilia</i>, or hairs that incompass it, so that it
+  seems this Creature has no very good foresight: It does not seem to have
+  any eye-lids, and therefore perhaps its eyes were so placed, that it
+  might the better cleanse them with its fore-legs; and perhaps this may be
+  the reason, why they so much avoid and run from the light behind them,
+  for being made to live in the shady and dark recesses of the hair, and
+  thence probably their eye having a great aperture, the open and clear
+  light, especially that of the Sun, must needs very much offend them; to
+  secure these eyes from receiving any injury from the hairs through which
+  it passes, it has two horns that grow before
+  it, in the place where one would have thought the eyes should be; each of
+  these CC hath four joynts, which are fringed, as 'twere, with small
+  brisles, from which to the tip of its snout D, the head seems very round
+  and tapering, ending in a very sharp nose D, which seems to have a small
+  hole, and to be the passage through which he sucks the blood. Now whereas
+  if it be plac'd on its back, with its belly upwards, as it is in the 35.
+  <i>Scheme</i>, it seems in several Positions to have a resemblance of
+  chaps, or jaws, as is represented in the Figure by EE, yet in other
+  postures those dark strokes disappear; and having kept several of them in
+  a box for two or three dayes, so that for all that time they had nothing
+  to feed on, I found, upon letting one creep on my hand, that it
+  immediately fell to sucking, and did neither seem to thrust its nose very
+  deep into the skin, nor to open any kind of mouth, but I could plainly
+  perceive a small current of blood, which came directly from its snout,
+  and past into its belly; and about A there seem'd a contrivance, somewhat
+  resembling a Pump, pair of Bellows, or Heart, for by a very swift
+  <i>systole</i> and <i>diastole</i> the blood seem'd drawn from the nose,
+  and forced into the body. It did not seem at all, though I viewed it a
+  good while as it was sucking, to thrust more of its nose into the skin
+  then the very snout D, nor did it cause the least discernable pain, and
+  yet the blood seem'd to run through its head very quick and freely, so
+  that it seems there is no part of the skin but the blood is dispers'd
+  into, nay, even into the <i>cuticula</i>; for had it thrust its whole
+  nose in from D to CC, it would not have amounted to the supposed
+  thickness of that <i>tegument</i>, the length of the nose being not more
+  then a three hundredth part of an inch. It has six legs, covered with a
+  very transparent shell, and joynted exactly like a Crab's, or Lobster's;
+  each leg is divided into six parts by these joynts, and those have here
+  and there several small hairs; and at the end of each leg it has two
+  claws, very properly adapted for its peculiar use, being thereby inabled
+  to walk very securely both on the skin and hair; and indeed this
+  contrivance of the feet is very curious, and could not be made more
+  commodiously and compendiously, for performing both these requisite
+  motions, of walking and climbing up the hair of a mans head, then it is:
+  for, by having the lesser claw (a) set so much short of the bigger (b)
+  when it walks on the skin the shorter touches not, and then the feet are
+  the same with those of a Mite, and several other small Insects, but by
+  means of the small joynts of the longer claw it can bend it round, and so
+  with both claws take hold of a hair, in the manner represented in the
+  Figure, the long transparent Cylinder FFF, being a Man's hair held by
+  it.</p>
+
+  <p>The <i>Thorax</i> seem'd cas'd with another kind of substance then the
+  belly, namely, with a thin transparent horny substance, which upon the
+  fasting of the Creature did not grow flaccid; through this I could
+  plainly see the blood, suck'd from my hand, to be variously distributed,
+  and mov'd to and fro; and about G there seem'd a pretty big white
+  substance, which seem'd to be moved within its <i>thorax</i>; besides,
+  there appear'd very many small milk-white vessels, which crost over the
+  breast between the legs, out of which, on either
+  side, were many small branchings, these seem'd to be the veins and
+  arteries, for that which is analogus to blood in all Insects is
+  milk-white.</p>
+
+  <p>The belly is covered with a transparent substance likewise, but more
+  resembling a skin then a shell, for 'tis grain'd all over the belly just
+  like the skin in the palms of a man's hand, and when the belly is empty,
+  grows very flaccid and wrinkled; at the upper end of this is placed the
+  stomach HH, and perhaps also the white spot II may be the liver or
+  <i>pancreas</i>, which, by the <i>peristalick</i> motion of the guts, is
+  a little mov'd to and fro, not with a <i>systole</i> and <i>diastole</i>,
+  but rather with a thronging or justling motion. Viewing one of these
+  Creatures, after it had fasted two dayes, all the hinder part was lank
+  and flaccid, and the white spot II hardly mov'd, most of the white
+  branchings disappear'd, and most also of the redness or sucked blood in
+  the guts, the <i>peristaltick</i> motion of which was scarce discernable;
+  but upon the suffering it to suck, it presently fill'd the skin of the
+  belly, and of the six scolop'd embosments on either side, as full as it
+  could be stuft, the stomach and guts were as full as they could hold; the
+  <i>peristaltick</i> motion of the gut grew quick, and the justling motion
+  of II accordingly; multitudes of milk-white vessels seem'd quickly
+  filled, and turgid, which were perhaps the veins and arteries and the
+  Creature was so greedy, that though it could not contain more, yet it
+  continued sucking as fast as ever, and as fast emptying it self behind:
+  the digestion of this Creature must needs be very quick, for though I
+  perceiv'd the blood thicker and blacker when suck'd, yet, when in the
+  guts, it was of a very lovely ruby colour, and that part of it, which was
+  digested into the veins, seemed white; whence it appears, that a further
+  digestion of blood may make it milk, at least of a resembling colour:
+  What is else observable in the figure of this Creature, may be seen by
+  the 35. <i>Scheme</i>.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLV" id="obsLV">LV</a>. <i>Of </i>Mites<i>.</i></h3>
+
+  <p>The least of <i>Reptiles</i> I have hitherto met with, is a Mite, a
+  Creature whereof there are some so very small, that the sharpest sight,
+  unassisted with Glasses, is not able to discern them, though, being white
+  of themselves, they move on a black and smooth surface; and the Eggs, out
+  of which these Creatures seem to be hatch'd, are yet smaller, those being
+  usually not above a four or five hundredth part of a well grown Mite, and
+  those well grown Mites not much above one hundredth of an inch in
+  thickness; so that according to this reckoning there may be no less then
+  a million of well grown Mites contain'd in a cubick inch, and five
+  hundred times as many Eggs.</p>
+
+  <p>Notwithstanding which minuteness a good <i>Microscope</i> discovers
+  those small movable specks to be very prettily shap'd Insects, each of
+  them furnished with eight well shap'd and proportion'd
+  legs, which are each of them joynted or bendable in eight several places,
+  or joynts, each of which is covered, for the most part, with a very
+  transparent shell, and the lower end of the shell of each joynt is
+  fringed with several small hairs; the contrivance of the joynts seems the
+  very same with that of Crabs and Lobsters legs, and like those also, they
+  are each of them terminated with a very sharp claw or point; four of
+  these legs are so placed, that they seem to draw forwards, the other four
+  are placed in a quite contrary position, thereby to keep the body
+  backwards when there is occasion.</p>
+
+<span class="sidenote">
+<a href="images/scheme-36.png" target="_blank"><i>Schem.</i> 36.</a><br /><i>Fig.</i> 1.
+</span>
+  <p>The body, as in other larger Insects, consists of three regions or parts; the
+  hinder or belly A, seems covered with one intire shell, the middle, or
+  chest, seems divided into two shells BC. which running one within the
+  other, the Mite is able to shrink in and thrust out as it finds occasion,
+  as it can also the snout D. The whole body is pretty transparent, so that
+  being look'd on against the light, divers motions within its body may be
+  perceived; as also all the parts are much more plainly delineable, then
+  in other postures, to the light. The shell, especially that which covers
+  the back, is curiously polisht, so that 'tis easie to see, as in a
+  <i>convex</i> Looking-glass, or <i>foliated</i> Glass-ball, the picture
+  of all the objects round about; up and down, in several parts of its
+  body, it has several small long white hairs growing out of its shell,
+  which are often longer then the whole body, and are represented too short
+  in the first and second Figures; they seem all pretty straight and
+  plyable, save only two upon the fore-part of its body, which seem to be
+  the horns, as may be seen in the Figures; the first whereof is a prospect
+  of a smaller sort of Mites (which are usually more plump) as it was
+  <i>passant</i> to and fro; the second is the prospect of one fixt on its
+  tail (by means of a little mouth-glew rub'd on the object plate)
+  exhibiting the manner of the growing of the legs, together with their
+  several joynts.</p>
+
+  <p>This Creature is very much diversify'd in shape, colour, and divers
+  other properties, according to the nature of the substance out of which
+  it seems to be ingendred and nourished, being in one substance more long,
+  in another more round, in some more hairy, in others more smooth, in this
+  nimble, in that slow, here pale and whiter, there browner, blacker, more
+  transparent, <i>&amp;c.</i> I have observed it to be resident almost on
+  all kinds of substances that are mouldy, or putrifying, and have seen it
+  very nimbly meshing through the thickets of mould, and sometimes to lye
+  <i>dormant</i> underneath them; and 'tis not unlikely, but that it may
+  feed on that vegetating substance, <i>spontaneous Vegetables</i> seeming
+  a food proper enough for <i>spontaneous Animals</i>,</p>
+
+  <p>But whether indeed this Creature, or any other, be such or not, I
+  cannot positively, from any Experiment, or Observation, I have yet made,
+  determine. But, as I formerly hinted, it seems probable, that some kind
+  of wandring Mite may sow, as 'twere, the first seeds, or lay the first
+  eggs, in those places, which Nature has instructed them to know
+  convenient for the hatching and nourishing their young; and though
+  perhaps the prime Parent might be of a shape very
+  differing from what the offspring, after a little while, by reason of the
+  substance they feed on, or the Region (as 'twere) they inhabite; yet
+  perhaps even one of these alter'd progeny, wandering again from its
+  native soil, and lighting on by chance the same place from whence its
+  prime Parent came, and there settling, and planting, may produce a
+  generation of Mites of the same shapes and properties with the first
+  wandring Mite: And from some such accidents as these, I am very apt to
+  think, the most sorts of Animals, generally accounted <i>spontaneous</i>,
+  have their <i>origination</i>, and all those various sorts of Mites, that
+  are to be met with up and down in divers putrifying substances, may
+  perhaps be all of the same kind, and have sprung from one and the same
+  sort of Mites at the first.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLVI" id="obsLVI">LVI</a>. <i>Of a small Creature hatch'd on a Vine.</i></h3>
+
+  <p>There is, almost all the Spring and Summer time, a certain small,
+  round, white Cobweb, as 'twere, about the bigness of a Pea, which sticks
+  very close and fast to the stocks of Vines nayl'd against a warm wall:
+  being attentively viewed, they seem cover'd, upon the upper side of them,
+  with a small husk, not unlike the scale, or shell of a Wood-louse, or
+  Hog-louse, a small Insect usually found about rotten wood, which upon
+  touching presently rouls it self into the form of a peppercorn:
+  Separating several of these from the stock, I found them, with my
+  <i>Microscope</i>, to consist of a shell, which now seemed more likely to
+  be the husk of one of these Insects: And the fur seem'd a kind of cobweb,
+  consisting of abundance of small filaments, or sleaves of cobwebs. In the
+  midst of this, if they were not hatch'd, and run away before, the time of
+  which hatching was usually about the latter end of <i>June</i>, or
+  beginning of <i>July</i>, I have often found abundance of small brown
+<span class="sidenote">
+<a href="images/scheme-36.png" target="_blank"><i>Schem.</i> 36.</a><br /><i>Fig.</i> 2.
+</span>
+  Eggs, such as A and B in the second Figure of the 36. <i>Scheme</i>, much
+  about the bigness of Mites Eggs; and at other times, multitudes of small
+  Insects, shaped exactly like that in the third Figure marked with X. Its
+  head large, almost half the bigness of its body, which is usual in the
+  <i>f&#339;tus</i> of most Creatures. It had two small black eyes
+  <i>aa</i>, and two small long joynted and brisled horns <i>bb</i>. The
+  hinder part of its body seem'd to consist of nine scales, and the last
+  ended in a forked tayl, much like that of a <i>Cutio</i>, or Wood louse,
+  out of which grew two long hairs; they ran to and fro very swiftly, and
+  were much of the bigness of a common Mite, but some of them less: The
+  longest of them seem'd not the hundredth part of an inch, and the Eggs
+  usually not above half as much. They seemed to have six legs, which were
+  not visible in this I have here delineated, by reason they were drawn
+  under its body.</p>
+
+  <p>If these Minute creatures were <i>Wood-lice</i> (as indeed from their
+  own shape and from the frame, the skin, or shell, that grows on them, one
+  may with great probability ghess) it affords us an
+  Instance, whereof perhaps there are not many like in Nature, and that is,
+  of the prodigious increase of these Creatures, after they are hatch'd and
+  run about; for a common Wood-louse, of about half an inch long, is no
+  less then a hundred and twenty five thousand times bigger then one of
+  these, which though indeed it seems very strange, yet I have observed the
+  young ones of some Spiders have almost kept the same proportion to their
+  Dam.</p>
+
+  <p>This, methinks, if it be so, does in the next place hint a Quæry,
+  which may perhaps deserve a little further examination: And that is,
+  Whether there be not many of those minute Creatures, such as Mites, and
+  the like, which, though they are commonly thought of otherwise, are only
+  the <i>pully</i>, or young ones, of much bigger Insects, and not the
+  generating, or parent <i>Insect</i>, that has layd those Eggs; for having
+  many times observ'd those Eggs, which usually are found in great
+  abundance where Mites are found, it seems something strange, that so
+  small an Animal should have an Egg so big in proportion to its body.
+  Though on the other side, I must confess, that having kept divers of
+  those Mites inclosed in a box for a good while, I did not find them very
+  much augmented beyond their usual bigness.</p>
+
+  <p>What the husk and cobweb of this little white substance should be, I
+  cannot imagine, unless it be, that the old one, when impregnated with
+  Eggs, should there stay, and fix it self on the Vine, and dye, and all
+  the body by degrees should rot, save only the husk, and the Eggs in the
+  body: And the heat, or fire, as it were, of the approaching Sun-beams
+  should vivifie those Relicts of the corrupted Parent, and out of the
+  ashes, as 'twere, (as it is fabled of the <i>Ph&#339;nix</i>) should
+  raise a new <i>offspring</i> for the perpetuation of the <i>Species</i>.
+  Nor will the cobweb, as it were, in which these Eggs are inclos'd, make
+  much against this Conjecture; for we may, by those cobwebs that are
+  carried up and down the Air after a Fog (which with my <i>Microscope</i>
+  I have discovered to be made up of an infinite company of small filaments
+  or threads) learn, that such a texture of body may be otherwise made then
+  by the spinning of a Worm.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLVII" id="obsLVII">LVII</a>. <i>Of the </i>Eels<i> in Vinegar.</i></h3>
+
+  <p>Of these small Eels, which are to be found in divers sorts of Vinegar,
+  I have little to add besides their Picture, which you may find drawn in
+<span class="sidenote">
+<a href="images/scheme-25.png" target="_blank"><i>Schem.</i> 25.</a><br /><i>Fig.</i> 3.
+</span>
+  the third Figure of the 25. <i>Scheme</i>: That is, they were shaped much
+  like an Eel, save only that their nose A, (which was a little more
+  opacous then the rest of their body) was a little sharper, and longer, in
+  proportion to their body, and the wrigling motion of their body seem'd to
+  be onely upwards and downwards, whereas that of Eels is onely side wayes:
+  They seem'd to have a more opacous part about B,
+  which might, perhaps, be their Gills; it seeming always the same
+  proportionate distant from their nose, from which, to the tip of their
+  tail, C, their body seem'd to taper.</p>
+
+  <p>Taking several of these out of their Pond of Vinegar, by the net of a
+  small piece of filtring Paper, and laying them on a black smooth Glass
+  plate, I found that they could wriggle and winde their body, as much
+  almost as a Snake, which made me doubt, whether they were a kind of Eal
+  or Leech.</p>
+
+  <p>I shall add no other observations made on this minute Animal, being
+  prevented herein by many excellent ones already publish'd by the
+  ingenious, Doctor <i>Power</i>, among his <i>Microscopical</i>
+  Observations, save onely that a quantity of Vinegar repleat with them
+  being included in a small Viol, and stop'd very close from the ambient
+  air, all the included Worms in a very short time died, as if they had
+  been stifled.</p>
+
+  <p>And that their motion seems (contrary to what we may observe in the
+  motion of all other Infects) exceeding slow. But the reason of it seems
+  plain, for being to move to and fro after that manner which they do, by
+  waving onely, or wrigling their body; the tenacity, or glutinousness, and
+  the density or resistance of the fluid <i>medium</i> becomes so exceeding
+  sensible to their extremely minute bodies, that it is to me indeed a
+  greater wonder that they move them so fast as they do, then that they
+  move them no faster. For what a vastly greater proportion have they of
+  their superficies to their bulk, then Eels or other larger Fishes, and
+  next, the tenacity and density of the liquor being much the same to be
+  moved, both by the one and the other, the resistance or impediment thence
+  arising to the motions made through it, must be almost infinitely greater
+  to the small one then to the great. This we find experimentally verify'd
+  in the Air, which though a <i>medium</i> a thousand times more rarify'd
+  then the water, the resistance of it to motions made through it, is yet
+  so sensible to very minute bodies, that a Down-feather (the least of
+  whose parts seem yet bigger then these Eels, and many of them almost
+  incomparably bigger, such as the quill and stalk) is suspended by it, and
+  carried to and fro as if it had no weight.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLVIII" id="obsLVIII">LVIII</a>. <i>Of a new Property in the </i>Air<i>, and several other
+transparent </i>Mediums<i> nam'd </i>Inflection<i>, whereby very many considerable
+</i>Phænomena<i> are attempted to be solv'd, and divers other
+uses are hinted.</i></h3>
+
+  <p>Since the Invention (and perfecting in some measure) of
+  <i>Telescopes</i>, it has been observ'd by several, that the Sun and Moon
+  neer the Horizon, are disfigur'd (losing that exactly-smooth terminating
+  circular limb, which they are observ'd to have when situated neerer the
+  Zenith) and are bounded with an edge every way (especially upon the right
+  and left sides) ragged and indented like a Saw:
+  which inequality of their limbs, I have further observ'd, not to remain
+  always the same, but to be continually chang'd by a kind of fluctuating
+  motion, not unlike that of the waves of the Sea, so as that part of the
+  limb, which was but even now nick'd or indented in, is now protuberant,
+  and will presently be sinking again; neither is this all but the whole
+  body of the Luminaries, do in the <i>Telescope</i>, seem to be depress'd
+  and slatted, the upper, and more especially the under side appearing
+  neerer to the middle then really they are, and the right and left
+  appearing more remote: whence the whole <i>Area</i> seems to be
+  terminated by a kind of Oval. It is further observ'd, that the body, for
+  the most part, appears red, or of some colour approaching neer unto it,
+  as some kind of yellow; and this I have always mark'd, that the more the
+  limb is slatted or ovalled, the more red does the body appear, though not
+  always the contrary. It is further observable, that both fix'd Stars and
+  Planets, the neerer they appear to the Horizon, the more red and dull
+  they look, and the more they are observ'd to twinkle; in so much, that I
+  have seen the Dog-starr to vibrate so strong and bright a radiation of
+  light, as almost to dazle my eyes, and presently, almost to disappear. It
+  is also observable, that those bright scintillations neer the Horizon,
+  are not by much so quick and sudden in their consecutions of one another,
+  as the nimbler twinklings of Stars neerer the Zenith. This is also
+  notable, that the Starrs neer the Horizon, are twinkled with several
+  colours; so as sometimes to appear red, sometimes more yellow, and
+  sometimes blue, and this when the Starr is a pretty way elevated above
+  the Horizon. I have further, very often seen some of the small Starrs of
+  the fifth or sixth magnitude, at certain times to disappear for a small
+  moment of time, and again appear more conspicuous, and with a greater
+  luster. I have several times, with my naked eye, seen many smaller
+  Starrs, such as may be call'd of the seventh or eighth magnitude to
+  appear for a short space, and then vanish, which, by directing a small
+  <i>Telescope</i> towards that part they appear'd and disappear'd in; I
+  could presently find to be indeed small Starrs so situate, as I had seen
+  them with my naked eye, and to appear twinkling like the ordinary visible
+  Stars; nay, in examining some very notable parts of the Heaven, with a
+  three foot Tube, me thought I now and then, in several parts of the
+  constellation, could perceive little twinklings of Starrs, making a very
+  short kind of apparition, and presently vanishing, but noting diligently
+  the places where they thus seem'd to play at boe-peep, I made use of a
+  very good twelve foot Tube, and with that it was not uneasie to see
+  those, and several other degrees of smaller Starrs, and some smaller yet,
+  that seem'd again to appear and disappear, and these also by giving the
+  same Object-glass a much bigger aperture, I could plainly and constantly
+  see appear in their former places; so that I have observ'd some twelve
+  several magnitudes of Starrs less then those of the six magnitudes
+  commonly recounted in the Globes.</p>
+
+  <p>It has been observ'd and confirm'd by the accuratest Observations of
+  the best of our modern Astronomers, that all the Luminous bodies appear
+  above the Horizon, when they really are below it. So that the
+  Sun and Moon have both been seen above the
+  Horizon, whil'st the Moon has been in an Eclipse. I shall not here
+  instance in the great refractions, that the tops of high mountains, seen
+  at a distance, have been found to have; all which seem to argue the
+  Horizontal refraction, much greater then it is hitherto generally
+  believ'd.</p>
+
+  <p>I have further taken notice, that not onely the Sun, Moon and Starrs,
+  and high tops of mountains have suffer'd these kinds of refraction, but
+  Trees, and several bright Objects on the ground: I have often taken
+  notice of the twinkling of the reflections of the Sun from a Glass-window
+  at a good distance, and of a Candle in the night, but that is not so
+  conspicuous, and in observing the setting Sun, I have often taken notice
+  of the tremulation of the Trees and Bushes, as well as of the edges of
+  the Sun. Divers of these <i>Phænomena</i> have been taken notice of by
+  several, who have given several reasons of them, but I have not yet met
+  with any altogether satisfactory, though some of their conjectures have
+  been partly true, but partly also false. Setting my self therfore upon
+  the inquiry of these <i>Phænomena</i>, I first endeavour'd to be very
+  diligent in taking notice of the several particulars and circumstances
+  observable in them; and next, in making divers particular Experiments,
+  that might cleer some doubts, and serve to determine, confirm, and
+  illustrate the true and adæquate cause of each; and upon the whole, I
+  find much reason to think, that the true cause of all these
+  <i>Phænomena</i> is from the <i>inflection</i>, or <i>multiplicate
+  refraction</i> of those Rays of light within the body of the
+  <i>Atmosphere</i>, and that it does not proceed from a <i>refraction</i>
+  caus'd by any terminating <i>superficies</i> of the Air above, nor from
+  any such exactly defin'd <i>superficies</i> within the body of the
+  <i>Atmosphere</i>.</p>
+
+  <p>This Conclusion is grounded upon these two Propositions:</p>
+
+  <p>First, that a <i>medium</i>, whose parts are unequally <i>dense</i>,
+  and mov'd by various motions and transpositions as to one another, will
+  produce all these visible effects upon the Rays of light, without any
+  other <i>coefficient</i> cause.</p>
+
+  <p>Secondly, that there is in the Air or <i>Atmosphere</i> such a variety
+  in the constituent parts of it, both as to their <i>density</i> and
+  <i>rarity</i>, and as to their divers mutations and positions one to
+  another.</p>
+
+  <p>By <i>Density</i> and <i>Rarity</i>, I understand a property of a
+  transparent body, that does either more or less refract a Ray of light
+  (coming obliquely upon its superficies out of a third <i>medium</i>)
+  toward its perpendicular: As I call Glass a more dense body then Water,
+  and Water a more rare body then Glass, because of the refractions (more
+  or less deflecting towards the perpendicular) that are made in them, of a
+  Ray of light out of the Air that has the same inclination upon either of
+  their superficies.</p>
+
+  <p>So as to the business of Refraction, spirit of Wine is a more
+  <i>dense</i> body then Water, it having been found by an accurate
+  Instrument that measures the angles of Refractions to Minutes that for
+  the same refracted angle of 30°.00'. in both those <i>Mediums</i>, the
+  angle of incidence in Water was but 41°.35'. but the angle of the
+  incidence in the trial with spirit of Wine was 42°.45'. But as to
+  gravity, Water is a more <i>dense</i> body then spirit of
+  Wine, for the proportion of the same Water, to the same very well
+  rectify'd spirit of Wine was, as 21. to 19.</p>
+
+  <p>So as to Refraction, Water is more Dense then Ice; for I have found by
+  a most certain Experiment, which I exhibited before divers illustrious
+  Persons of the <i>Royal Society</i>, that the Refraction of Water was
+  greater then that of Ice, though some considerable Authors have affirm'd
+  the contrary, and though the Ice be a very hard, and the Water a very
+  fluid body.</p>
+
+  <p>That the former of the two preceding Propositions is true, may be
+  manifested by several Experiments; As first, if you take any two liquors
+  differing from one another in density, but yet such as will readily mix:
+  as Salt Water, or Brine, &amp; Fresh; almost any kind of Salt dissolv'd
+  in Water, and filtrated, so that it be cleer, spirit of Wine and Water;
+  nay, spirit of Wine, and spirit of Wine, one more highly rectify'd then
+  the other, and very many other liquors; if (I say) you take any two of
+  these liquors, and mixing them in a Glass Viol, against one side of which
+  you have fix'd or glued a small round piece of Paper, and shaking them
+  well together (so that the parts of them may be somewhat disturb'd and
+  move up and down) you endeavour to see that round piece of Paper through
+  the body of the liquors, you shall plainly perceive the Figure to wave,
+  and to be indented much after the same manner as the limb of the Sun
+  through a <i>Telescope</i> seems to be, save onely that the mutations
+  here, are much quicker. And if, in steed of this bigger Circle, you take
+  a very small spot, and fasten and view it as the former, you will find it
+  to appear much like the twinkling of the Starrs, though much quicker:
+  which two <i>Phænomena</i>, (for I shall take notice of no more at
+  present, though I could instance in multitudes of others) must
+  necessarily be caus'd by an <i>inflection</i> of the Rays within the
+  terminating superficies of the compounded <i>medium</i>, since the
+  surfaces of the transparent body through which the Rays pass to the eye,
+  are not at all altered or chang'd.</p>
+
+  <p>This <i>inflection</i> (if I may so call it) I imagine to be nothing
+  else, but a <i>multiplicate refraction</i>, caused by the unequal
+  <i>density</i> of the constituent parts of the <i>medium</i>, whereby the
+  motion, action or progress of the Ray of light is hindred from proceeding
+  in a streight line, and <i>inflected</i> or <i>deflected</i> by a
+  <i>curve</i>. Now, that it is a <i>curve</i> line is manifest by this
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 1.
+</span>
+  Experiment: I took a Box, such as ADGE, in the first <i>Figure</i> of the
+  37. <i>Scheme</i>, whose sides ABCD, and EFGH, were made of two smooth
+  flat plates of Glass, then filling it half full with a very strong
+  solution of Salt, I filled the other half with very fair fresh water,
+  then exposing the opacous side, DHGC, to the Sun, I observ'd both the
+  <i>refraction</i> and <i>inflection</i> of the Sun beams, ID &amp; KH,
+  and marking as exactly as I could, the points, P, N, O, M, by which the
+  Ray, KH, passed through the compounded <i>medium</i>, I found them to be
+  in a <i>curve</i> line; for the parts of the <i>medium</i> being
+  continually more dense the neerer they were to the bottom, the Ray
+  <i>pf</i> was continually more and more deflected downwards from the
+  streight line.</p>
+
+  <p>This Inflection may be mechanically explained, either by Monsieur
+  <i>Des Cartes</i> principles by conceiving
+  the Globuls of the third Element to find less and less resistance against
+  that side of them which is downwards, or by a way, which I have further
+  explicated in the Inquisition about Colours, to be from an obliquation of
+  the pulse of light, whence the under part is continually promoted, and
+  consequently refracted towards the perpendicular, which cuts the Orbs at
+  right angles. What the particular Figure of the <i>Curve line</i>,
+  describ'd by this way of light, is, I shall not now stand to examine,
+  especially since there may be so many sorts of it as there may be
+  varieties of the Positions of the <i>intermediat</i> degrees of
+  <i>density</i> and <i>rarity</i> between the bottom and the top of the
+  inflecting Medium.</p>
+
+  <p>I could produce many more Examples and Experiments, to illustrate and
+  prove this first Proposition, <i>viz.</i> that there is such a
+  constitution of some bodies as will cause inflection. As not to mention
+  those I have observ'd in <i>Horn</i>, <i>Tortoise-Shell</i>,
+  <i>transparent Gums</i>, and <i>resinous Substances</i>: The <i>veins</i>
+  of Glass, nay, of melted <i>Crystal</i>, found, and much complained of by
+  Glass-grinders, and others, might sufficiently demonstrate the truth of
+  it to any diligent Observator.</p>
+
+  <p>But that, I presume, I have by this Example given proof sufficient
+  (<i>viz. ocular demonstration</i>) to evince, that there is such a
+  modulation, or bending of the rayes of light, as I have call'd
+  <i>inflection</i>, differing both from <i>reflection</i>, and
+  <i>refraction</i> (since they are both made in the superficies, this only
+  in the middle); and likewise, that this is able or sufficient to produce
+  the effects I have ascribed to it.</p>
+
+  <p>It remains therefore to shew, that there is such a property in the
+  Air, and that it is sufficient to produce all the above mentioned
+  <i>Phænomena</i>, and therefore may be the principal, if not the only
+  cause of them.</p>
+
+  <p>First, That there is such a property, may be proved from this, that
+  the parts of the Air are some of them more condens'd, others more
+  rarified, either by the differing heat, or differing pressure it
+  sustains, or by the somewhat heterogeneous vapours interspers'd through
+  it. For as the Air is more or less rarified, so does it more or less
+  refract a ray of light (that comes out of a denser medium) from the
+  perpendicular. This you may find true, if you make tryal of this
+  Experiment.</p>
+
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 2.
+</span>
+  <p>Take a small Glass-bubble, made in the form of that in the second
+  Figure of the 37. <i>Scheme</i>, and by heating the Glass very hot, and
+  thereby very much rarifying the included Air, or, which is better, by
+  rarifying a small quantity of water, included in it, into vapours, which
+  will expel the most part, if not all the Air, and then sealing up the
+  small neck of it, and letting it cool, you may find, if you place it in a
+  convenient Instrument, that there will be a manifest difference, as to
+  the refraction.</p>
+
+  <p>As if in this second Figure you suppose A to represent a small sight
+  or hole, through which the eye looks upon an object, as C, through the
+  Glass-bubble B, and the second sight L; all which remain exactly fixt in
+  their several places, the object C being so cized and placed, that it may
+  just seem to touch the upper and under edge of the hole L: and so all of
+  it be seen through the small Glass-ball of rarified Air; then by
+  breaking off the small seal'd neck of the
+  Bubble (without at all stirring the sights, object, or glass) and
+  admitting the external Air, you will find your self unable to see the
+  utmost ends of the object; but the terminating rayes AE and AD (which
+  were before refracted to G and F by the rarified Air) will proceed almost
+  directly to I and H; which alteration of the rayes (seeing there is no
+  other alteration made in the Organ by which the Experiment is tryed, save
+  only the admission, or exclusion of the condens'd Air) must necessarily
+  be caused by the variation of the <i>medium</i> contain'd in the Glass B;
+  the greatest difficulty in the making of which Experiment, is from the
+  uneven surfaces of the bubble, which will represent an uneven image of
+  the object.</p>
+
+  <p>Now, that there is such a difference of the upper and under parts of
+  the Air is clear enough evinc'd from the late improvement of the
+  <i>Torricellian</i> Experiment, which has been tryed at the tops and feet
+  of Mountains; and may be further illustrated, and inquired into, by a
+  means, which some whiles since I thought of, and us'd, for the finding by
+  what degrees the Air passes from such a degree of Density to such a
+  degree of Rarity. And another, for the finding what pressure was
+  requisite to make it pass from such a degree of Rarefaction to a
+  determinate Density: Which Experiments, because they may be useful to
+  illustrate the present Inquiry, I shall briefly describe.</p>
+
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 3.
+</span>
+  <p>I took then a small Glass-pipe AB, about the bigness of a Swans quill, and about
+  four foot long, which was very equally drawn, so that, as far as I could
+  perceive, no one part was bigger then another: This Tube (being open at
+  both ends) I fitted into another small Tube DE, that had a small bore
+  just big enough to contain the small Pipe, and this was seal'd up at one,
+  and open at the other, end; about which open end I fastned a small wooden
+  box C with cement, so that filling the bigger Tube, and part of the box,
+  with Quicksilver, I could thrust the smaller Tube into it, till it were
+  all covered with the Quicksilver: Having thus done, I fastned my bigger
+  Tube against the side of a wall, that it might stand the steadier, and
+  plunging the small Tube cleer under the <i>Mercury</i> in the box, I
+  stopt the upper end of it very fast with cement, then lifting up the
+  small Tube, I drew it up by a small pully, and a string that I had
+  fastned to the top of the Room, and found the height of the <i>Mercurial
+  Cylinder</i> to be about twenty nine inches.</p>
+
+  <p>Then letting down the Tube again, I opened the top, and then thrust
+  down the small Tube, till I perceived the Quicksilver to rise within it
+  to a mark that I had plac'd just an inch from the top; and immediately
+  clapping on a small piece of cement that I had kept warm, I with a hot
+  Iron seal'd up the top very fast, then letting it cool (that both the
+  cement might grow hard, and more especially, that the Air might come to
+  its temper, natural for the Day I try'd the Experiment in) I observ'd
+  diligently, and found the included Air to be exactly an Inch.</p>
+
+  <p>Here you are to take notice, that after the Air is seal'd up, the top
+  of the Tube is not to be elevated above the superficies of the
+  Quicksilver in the box, till the surface of that within
+  the Tube be equal to it, for the Quicksilver (as I have elsewhere prov'd)
+  being more heterogeneous to the Glass then the Air, will not naturally
+  rise up so high within the small Pipe, as the superficies of the
+  <i>Mercury</i> in the box, and therefore you are to observe, how much
+  below the outward superficies of the <i>Mercury</i> in the box, that of
+  the same in the Tube does stand, when the top being open, free ingress is
+  admitted to the outward Air.</p>
+
+  <p>Having thus done, I permitted the <i>Cylinder</i>, or small Pipe, to
+  rise out of the box, till I found the surface of the Quicksilver in the
+  Pipe to be two inches above that in the box, and found the Air to have
+  expanded it self but one sixteenth part of an inch; then drawing up the
+  small pipe, till I found the height of the Quicksilver within to be four
+  inches above that without, I observed the Air to be expanded only 1/7 of
+  an inch more then it was at first, and to take up the room of 1-1/7 inch:
+  then I raised the Tube till the Cylinder was six inches high, and found
+  the Air to take up 1-2/9 inches of room in the Pipe; then to 8, 10, 12.
+  <i>&amp;c.</i> the expansion of the Air that I found to each of which
+  Cylinders are set down in the following Table; where the first row
+  signifies the height of the <i>Mercurial Cylinder</i>; the next, the
+  expansion of the Air; the third, the pressure of the <i>Atmosphere</i>,
+  or the highest <i>Cylinder</i> of <i>Mercury</i>, which was then neer
+  thirty inches: The last signifies the force of the Air so expanded, which
+  is found by substracting the first row of numbers out of the third; for
+  having found, that the outward Air would then keep up the Quicksilver to
+  thirty inches, look whatever of that height is wanting must be attributed
+  to the Elater of the Air depressing. And therefore having the Expansion
+  in the second row, and the height of the subjacent <i>Cylinder</i> of
+  <i>Mercury</i> in the first, and the greatest height of the
+  <i>Cylinder</i> of <i>Mercury</i>, which of it self counterballances the
+  whole pressure of the <i>Atmosphere</i>; by substracting the numbers of
+  the first row out of the numbers of the third, you will have the measure
+  of the <i>Cylinders</i> so deprest, and consequently the force of the
+  Air, in the several Expansions, registred.</p>
+
+<pre>
+  The height of the     The Expansion   The height of   The strength
+  Cylinder of <i>Mercury</i>,  of the Air.     the <i>Mercury</i>     of the Elater
+  that, together with                   that counter-   of the expanded
+  the Elater of the                     ballanc'd the   Air.
+  included Air,                         Atmosphere.
+  ballanced the
+  pressure of the
+  Atmosphere.
+   ----------            ----------      ----------      ----------
+      00                    01               30              30
+      02                    01-1/16          30              28
+      04                    01-1/7           30              26
+      06                    01-2/9           30              24
+      08                    01-1/3           30              22
+      10                    01-1/2           30              20
+      12                    01-2/3           30              18
+      14                    01-5/6           30              16
+      16                    02-2/27          30              14
+      18                    02-4/9           30              12
+      20                    03               30              10
+      22                    03-7/9           30               8
+      24                    05-7/18          30               6
+      25                    06-2/3           30               5
+      26                    08-1/2           30               4
+      26-1/4                09-1/2           30               3-3/4
+      26-1/2                10-3/4           30               3-1/2
+      26-3/4                13               30               3-1/4
+      27                    15-1/2           30               3
+
+</pre>
+
+  <p>I had several other Tables of my Observations, and Calculations, which
+  I then made; but it being above a twelve month since I made them; and by
+  that means having forgot many circumstances and particulars, I was
+  resolved to make them over once again, which I did <i>August</i> the
+  second 1661. with the very same Tube which I used the year before, when I
+  first made the Experiment (for it being a very good one, I had carefully
+  preserv'd it:) And after having tryed it over and over again; and being
+  not well satisfied of some particulars, I, at last, having put all things
+  in very good order, and being as attentive, and observant, as possibly I
+  could, of every circumstance requisite to be taken notice of, did
+  register my several Observations in this following Table. In the making
+  of which, I did not exactly follow the method that I had used at first;
+  but, having lately heard of Mr. <i>Townly</i>'s <i>Hypothesis</i>, I
+  shap'd my course in such sort, as would be most convenient for the
+  examination of that <i>Hypothesis</i>; the event of which you have in the
+  latter part of the last Table.</p>
+
+  <p>The other Experiment was, to find what degrees of force were requisite
+  to compress, or condense, the Air into such or such a bulk.</p>
+
+  <p>The manner of proceeding therein was this: I took a Tube about five
+  foot long, one of whose ends was sealed up, and bended in the form of a
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 4.
+</span>
+  <i>Syphon</i>, much like that represented in the fourth Figure of the 37.
+  <i>Scheme</i>, one side whereof AD, that was open at A, was about fifty
+  inches long, the other side BC, shut at B, was not much above seven
+  inches long, then placing it exactly perpendicular, I pour'd in a little
+  Quicksilver, and found that the Air BC was 6-7/8 inches, or very near to
+  seven; then pouring in Quicksilver at the longer Tube, I continued
+  filling of it till the Air in the shorter part of it was contracted into
+  half the former dimensions, and found the height exactly nine and twenty
+  inches; and by making several other tryals, in several other degrees of
+  condensation of the Air, I found them exactly answer the former
+  <i>Hypothesis</i>.</p>
+
+  <p>But having (by reason it was a good while since I first made)
+  forgotten many particulars, and being much unsatisfied in others, I made
+  the Experiment over again, and, from the several tryals, collected the
+  former part of the following Table: Where in the row next the left hand
+  24. signifies the dimensions of the Air, sustaining only the pressure of
+  the <i>Atmosphere</i>, which at that time was equal to a <i>Cylinder</i>
+  of <i>Mercury</i> of nine and twenty inches: The next Figure above it
+  (20) was the dimensions of the Air induring the first compression, made
+  by a <i>Cylinder</i> of <i>Mercury</i> 5-3/16 high, to which the pressure
+  of the <i>Atmosphere</i> nine and twenty inches being added, the elastick
+  strength of the Air so comprest will be found 34-3/16, &amp;c.</p>
+
+<h3><i>A Table of the Elastick power of the Air,
+both Experimentally and Hypothetically calculated,
+according to its various Dimensions.</i></h3>
+
+<pre>
+
+  The dimensions   The height    The <i>Mercurial</i>  The sum or  What they
+  of the included  of the        <i>Cylinder</i>       difference  ought to
+  Air.             <i>Mercurial</i>     added, or      of these    be according
+                   <i>Cylinder</i>      taken from     two         to the
+                   counter-      the former.    <i>Cylinders</i>.  <i>Hypothesis</i>.
+                   pois'd
+                   by the
+                   Atmosphere.
+   ----------      ----------     ----------     ----------  ----------
+       12             29      +     29         =   58          58
+       13             29      +     24-11/16   =   53-11/16    53-7/13
+       14             29      +     20-3/16    =   49-3/16     49-5/7
+       16             29      +     14         =   43          43-1/2
+       18             29      +      9-1/8     =   38-1/8      38-2/3
+       20             29      +      5-3/16    =   34-3/16     34-4/5
+       24             29             0         =   29          29
+       48             29      -     14-5/8     =   14-3/8      14-1/2
+       96             29      -     22-1/8     =    6-7/8       7-2/8
+      192             29      -     25-5/8     =    3-3/8       3-5/8
+      384             29      -     27-2/8     =    1-6/8       1-7/16
+      576             29      -     27-7/8     =    1-1/8       1-5/24
+      768             29      -     28-1/8     =    0-7/8       0-[7-1/4]/8
+      960             29      -     28-3/8     =    0-5/8       0-[5-4/5]/8
+     1152             29      -     28-7/16    =    0-9/16      0-10/16
+
+</pre>
+
+  <p>From which Experiments, I think, we may safely conclude, that the
+  Elater of the Air is reciprocal to its extension, or at least very neer.
+  So that to apply it to our present purpose (which was indeed the chief
+  cause of inventing these wayes of tryal) we will suppose a
+  <i>Cylinder</i> indefinitely extended upwards, [I say a <i>Cylinder</i>,
+  not a piece of a <i>Cone</i>, because, as I may elsewhere shew in the
+  Explication of Gravity, that <i>triplicate</i> proportion of the shels of
+  a Sphere, to their respective diameters, I suppose to be removed in this
+  case by the decrease of the power of Gravity] and the pressure of the Air
+  at the bottom of this <i>Cylinder</i> to be strong enough to keep up a
+  <i>Cylinder</i> of <i>Mercury</i> of thirty inches: Now because by the
+  most accurate tryals of the most illustrious and incomparable Mr.
+  <i>Boyle</i>, published in his deservedly famous Pneumatick Book, the
+  weight of Quicksilver, to that of the Air here below, is found neer about
+  as fourteen thousand to one: If we suppose the parts of the
+  <i>Cylinder</i> of the <i>Atmosphere</i> to be every where of an equal
+  density, we shall (as he there deduces) find it extended to the height of
+  thirty five thousand feet, or seven miles: But because by these
+  Experiments we have somewhat confirm'd the hypothesis of the reciprocal
+  proportion of the Elaters to the Extensions we shall find, that by
+  supposing this <i>Cylinder</i> of the <i>Atmosphere</i> divided into a
+  thousand parts, each of which being equivalent to thirty five feet, or
+  seven geometrical paces, that is, each of these divisions containing as
+  much Air as is suppos'd in a <i>Cylinder</i> neer the earth of equal
+  diameter, and thirty five foot high, we shall find the lowermost to press
+  against the surface of the Earth with the whole weight of the above
+  mentioned thousand parts; the pressure of the bottom of the second
+  against the top of the first to be 1000 - 1 = 999. of the third against
+  the second to be 1000 - 2 = 998. of the fourth against the third to be
+  1000 - 3 = 997. of the uppermost against the 999. or that next below it,
+  to be 1000 - 999 = 1. so that the extension of the lowermost next the
+  Earth, will be to the extension of the next below the uppermost, as 1. to
+  999. for as the pressure sustained by the 999. is to the pressure
+  sustain'd by the first, so is the extension of the first to the extension
+  of the 999. so that, from this hypothetical calculation, we shall find
+  the Air to be indefinitely extended: For if we suppose the whole
+  thickness of the Air to be divided, as I just now instanced, into a
+  thousand parts, and each of those under differing Dimensions, or
+  Altitudes, to contain an equall quantity of Air, we shall find, that the
+  first <i>Cylinder</i>, whose Base is supposed to lean on the Earth, will
+  be found to be extended 35-35/999 foot; the second equal Division, or
+  <i>Cylinder</i>, whose <i>basis</i> is supposed to lean on the top of the
+  first, shall have its top extended higher by 35-70/998 the third
+  35-105/997 the fourth 35-140/996 and so onward, each equal quantity of
+  Air having its dimensions measured by 35. and some additional number
+  exprest alwayes in the manner of a fraction, whose numerator is alway the
+  number of the place multipli'd by 35. and whose denominator is alwayes
+  the pressure of the <i>Atmosphere</i> sustain'd by that part, so that by
+  this means we may easily calculate the height of 999. divisions of those
+  1000. divisions, I suppos'd; whereas the uppermost may
+  extend it self more then as high again, nay, perhaps indefinitely, or
+  beyond the Moon; for the Elaters and Expansions being in reciprocal
+  proportions, since we cannot yet find the <i>plus ultra</i>, beyond which
+  the Air will not expand it self, we cannot determine the height of the
+  Air: for since, as we have shewn, the proportion will be alway as the
+  pressure sustain'd by any part is to 35. so 1000. to the expansion of
+  that part; the multiplication or product therefore of the pressure, and
+  expansion, that is, of the two extream proportionals, being alwayes equal
+  to the product of the means, or 35000. it follows, since that Rectangle
+  or Product may be made up of the multiplication of infinite diversities
+  of numbers, that the height of the Air is also indefinite; for since (as
+  far as I have yet been able to try) the Air seems capable of an
+  indefinite Expansion, the pressure may be decreased in <i>infinitum</i>,
+  and consequently its expansion upwards indefinite also.</p>
+
+  <p>There being therefore such a difference of density, and no Experiment
+  yet known to prove a <i>Saltus</i>, or skipping from one degree of rarity
+  to another much differing from it, that is, that an upper part of the Air
+  should so much differ from that immediately <i>subjacent</i> to it, as to
+  make a distinct superficies, such as we observe between the Air and
+  Water, <i>&amp;c.</i> But it being more likely, that there is a continual
+  increase of rarity in the parts of the Air, the further they are removed
+  from the surface of the Earth: It will hence necessarily follow, that (as
+  in the Experiment of the salt and fresh Water) the ray of Light passing
+  obliquely through the Air also, which is of very different density, will
+  be continually, and infinitely inflected, or bended, from a streight, or
+  direct motion.</p>
+
+  <p>This granted, the reason of all the above recited <i>Phænomena</i>,
+  concerning the appearance of the Celestial Bodies, will very easily be
+  deduced. As,</p>
+
+  <p>First, The redness of the Sun, Moon, and Stars, will be found to be
+  caused by the inflection of the rays within the <i>Atmosphere</i>. That
+  it is not really in or near the luminous bodies, will, I suppose, be very
+  easily granted, seeing that this redness is observable in several places
+  differing in Longitude, to be at the same time different, the setting and
+  rising Sun of all parts being for the most part red:</p>
+
+  <p>And secondly, That it is not meerly the colour of the Air interpos'd,
+  will, I suppose, without much more difficulty be yielded, seeing that we
+  may observe a very great <i>interstitium</i> of Air betwixt the Object,
+  and the Eye, makes it appear of a dead blew, far enough differing from a
+  red, or yellow.</p>
+
+  <p>But thirdly, That it proceeds from the refraction, or inflection, of
+  the rays by the <i>Atmosphere</i>, this following Experiment will, I
+  suppose, sufficiently manifest.</p>
+
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 5.
+</span>
+  <p>Take a sphærical Crystalline Viol, such as is describ'd in the fifth
+  Figure ABCD, and, having fill'd it with pure clear Water, expose it to
+  the Sun beams; then taking a piece of very fine <i>Venice</i> Paper,
+  apply it against that side of the Globe that is opposite to the Sun, as
+  against the side BC, and you shall perceive a bright
+  red Ring to appear, caus'd by the refraction of the Rays, AAAA, which is
+  made by the Globe; in which Experiment, if the Glass and Water be very
+  cleer, so that there be no Sands nor bubbles in the Glass, nor dirt in
+  the Water, you shall not perceive any appearance of any other colour. To
+  apply which Experiment, we may imagine the <i>Atmosphere</i> to be a
+  great transparent Globe, which being of a substance more dense then the
+  other, or (which comes to the same) that has its parts more dense towards
+  the middle, the Sun beams that are tangents, or next within the tangents
+  of this Globe, will be refracted or inflected from their direct passage
+  towards the center of the Globe, whence, according to the laws of
+  refractions made in a triangular <i>Prism</i>, and the generation of
+  colour set down in the description of Muscovi-glass there must
+  necessarily appear a red colour in the <i>transitus</i> or passage of
+  those tangent Rays. To make this more plain, we will suppose (in the
+  sixth <i>Figure</i>) ABCD, to represent the Globe of the
+  <i>Atmosphere</i>, EFGH to represent the opacous Globe of the Earth,
+  lying in the midst of it, neer to which, the parts of the Air, sustaining
+  a very great pressure, are thereby very much condens'd, from whence those
+  Rays that are by inflection made tangents to the Globe of the Earth, and
+  those without them, that pass through the more condens'd part of the
+  <i>Atmosphere</i>, as suppose between A and E, are by reason of the
+  inequality of the <i>medium</i>, inflected towards the center, whereby
+  there must necessarily be generated a red colour, as is more plainly
+  shewn in the former cited place; hence whatsoever opacous bodies (as
+  vapours, or the like) shall chance to be elevated into those parts, will
+  reflect a red towards the eye; and therefore those evenings and mornings
+  appear reddest, that have the most store of vapours and halituous
+  substances exhaled to a convenient distance from the Earth; for thereby
+  the inflection is made the greater, and thereby the colour also the more
+  intense; and several of those exhalations being opacous, reflect several
+  of those Rays, which, through an <i>Homogeneous</i> transparent
+  <i>medium</i> would pass unseen; and therefore we see, that when there
+  chances to be any clouds situated in those Regions they reflect a strong
+  and vivid red. Now, though one great cause of the redness may be this
+  inflection, yet I cannot wholly exclude the colour of the vapours
+  themselves, which may have something of redness in them, they being
+  partly nitrous; and partly fuliginous; both which steams tinge the Rays
+  that pass through them, as is made evident by looking at bodies through
+  the fumes of <i>Aqua fortis</i> or spirit of <i>Nitre</i> [as the newly
+  mentioned Illustrious Person has demonstrated] and also through the smoak
+  of a Fire or Chimney.</p>
+
+  <p>Having therefore made it probable at least, that the morning and
+  evening redness may partly proceed from this inflection or refraction of
+  the Rays, we shall next shew how the Oval Figure will be likewise easily
+  deduced.</p>
+
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 6.
+</span>
+  <p>Suppose we therefore, EFGH in the sixth <i>Figure</i> of the 37.
+  <i>Scheme</i>, to represent the Earth; ABCD, the <i>Atmosphere</i>; EI,
+  and EL, two Rays coming from the Sun, the one from the upper, the other
+  from the neather Limb, these Rays, being by the
+  <i>Atmosphere</i> inflected, appear to the eye at E, as if they had come
+  from the points, N and O; and because the Ray L has a greater inclination
+  upon the inequality of the <i>Atmosphere</i> then I, therefore must it
+  suffer a greater inflection, and consequently be further elevated above
+  its true place, then the Ray I, which has a less inclination, will be
+  elevated above its true place; whence it will follow, that the lower side
+  appearing neerer the upper then really it is, and the two <i>lateral</i>
+  sides, <i>viz.</i> the right and left side, suffering no sensible
+  alteration from the inflection, at least what it does suffer, does rather
+  increase the visible Diameter then diminish it, as I shall shew by and
+  by, the Figure of the luminous body must necessarily appear somewhat
+  <i>Elliptical</i>.</p>
+
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 7.
+</span>
+  <p>This will be more plain, if in the seventh <i>Figure</i> of the 37.
+  <i>Scheme</i> we suppose AB to represent the sensible Horizon; CDEF, the
+  body of the Sun really below it; GHIK, the same appearing above it,
+  elevated by the inflection of the <i>Atmosphere</i>: For if, according to
+  the best observation, we make the visible Diameter of the Sun to be about
+  three or four and thirty minutes, and the Horizontal refraction according
+  to <i>Ticho</i> be thereabout, or somewhat more, the lower limb of the
+  Sun E, will be elevated to I; but because, by his account, the point C
+  will be elevated but 29. minutes, as having not so great an inclination
+  upon the inequality of the Air, therefore IG, which will be the apparent
+  refracted perpendicular Diameter of the Sun, will be less then CG, which
+  is but 29. minutes, and consequently six or seven minutes shorter then
+  the unrefracted apparent Diameter. The parts, D and F, will be likewise
+  elevated to H and K, whose refraction, by reason of its inclination, will
+  be bigger then that of the point C, though less then that of E; therefore
+  will the semidiameter IL, be shorter then LG, and consequently the under
+  side of the appearing Sun more flat then the upper.</p>
+
+  <p>Now, because the Rays from the right and left sides of the Sun,
+  <i>&amp;c.</i> have been observ'd by <i>Ricciolo</i> and
+  <i>Grimaldus</i>, to appear more distant one from another then really
+  they are, though (by very many Observations that I have made for that
+  purpose, with a very good <i>Telescope</i>, fitted with a divided Ruler)
+  I could never perceive any great alteration, yet there being really some,
+  it will not be amiss, to shew that this also proceeds from the refraction
+  or inflection of the <i>Atmosphere</i>; and this will be manifest, if we
+  consider the <i>Atmosphere</i> as a transparent Globe, or at least a
+  transparent shell, encompassing an opacous Globe, which, being more dense
+  then the <i>medium</i> encompassing it, refracts or inflects all the
+  entring parallel Rays into a point or focus, so that wheresoever the
+  Observator is plac'd within the <i>Atmosphere</i>, between the focus and
+  the luminous body, the <i>lateral</i> Rays must necessarily be more
+  converg'd towards his eye by the refraction or inflection, then they
+  would have been without it; and therefore the Horizontal Diameter of the
+  luminous body must necessarily be augmented.</p>
+
+  <p>This might be more plainly manifest to the eye by the sixth
+  <i>Figure</i>; but because it would be somwhat tedious, and the thing
+  being obvious enough to be imagin'd by any one that
+  attentively considers it, I shall rather omit it, and proceed to shew,
+  that the mass of Air neer the surface of the Earth, consists, or is made
+  up, of parcels, which do very much differ from one another in point of
+  density and rarity; and consequently the Rays of light that pass through
+  them will be variously inflected, here one way, and there another,
+  according as they pass so or so through those differing parts; and those
+  parts being always in motion, either upwards or downwards, or to the
+  right or left, or in some way compounded of these, they do by this their
+  motion inflect the Rays, now this way, and presently that way.</p>
+
+  <p>This irregular, unequal and unconstant inflection of the Rays of
+  light, is the reason why the limb of the <i>Sun</i>, <i>Moon</i>,
+  <i>Jupiter</i>, <i>Saturn</i>, <i>Mars</i>, and <i>Venus</i>, appear to
+  wave or dance; and why the body of the Starrs appear to tremulate or
+  twinkle, their bodies, by this means, being sometimes magnify'd, and
+  sometimes diminished; sometimes elevated, otherwhiles depress'd; now
+  thrown to the right hand, and then to the left.</p>
+
+  <p>And that there is such a property or unequal distribution of parts, is
+  manifest from the various degrees of heat and cold that are found in the
+  Air; from whence will follow a differing density and rarity, both as to
+  quantity and refraction; and likewise from the vapours that are
+  interpos'd, (which, by the way, I imagine, as to refraction or
+  inflection, to do the same thing, as if they were rarify'd Air; and that
+  those vapours that ascend, are both lighter, and less dense, then the
+  ambient Air which boys them up; and that those which descend, are heavier
+  and more dense) The first of these may be found true, if you take a good
+  thick piece of Glass, and heating it pretty hot in the fire, lay it upon
+  such another piece of Glass, or hang it in the open Air by a piece of
+  Wire, then looking upon some far distant Object (such as a Steeple or
+  Tree) so as the Rays from that Object pass directly over the Glass before
+  they enter your eye, you shall find such a tremulation and wavering of
+  the remote Object, as will very much offend your eye: The like tremulous
+  motion you may observe to be caus'd by the ascending steams of Water, and
+  the like. Now, from the first of these it is manifest, that from the
+  rarifaction of the parts of the Air, by heat, there is caus'd a differing
+  refraction, and from the ascension of the more rarify'd parts of the Air,
+  which are thrust up by the colder, and therefore more condens'd and
+  heavie, is caus'd an undulation or wavering of the Object; for I think,
+  that there are very few will grant, that Glass, by as gentle a heat as
+  may be endur'd by ones hand, should send forth any of its parts in steams
+  or vapours, which does not seem to be much wasted by that violent fire of
+  the green Glass-house; but, if yet it be doubted, let Experiment be
+  further made with that body that is accounted, by Chymists and others,
+  the most ponderous and fix'd in the world; for by heating of a piece of
+  Gold, and proceeding in the same manner, you may find the same
+  effects.</p>
+
+  <p>This trembling and shaking of the Rays, is more sensibly caus'd by an
+  actual flame, or quick fire, or anything else heated glowing hot; as by a
+  Candle, live Coal, red-hot Iron, or a piece of Silver, and the like: the
+  same also appears very conspicuous, if you look at an Object betwixt
+  which and your eye, the rising smoak of
+  some Chimney is interpos'd; which brings into my mind what I had once the
+  opportunity to observe, which was, the Sun rising to my eye just over a
+  Chimney that sent forth a copious steam of smoak; and taking a short
+  <i>Telescope</i>, which I had then by me, I observ'd the body of the Sun,
+  though it was but just peep'd above the Horizon, to have its underside,
+  not onely flatted, and press'd inward, as it usually is when neer the
+  Earth; but to appear more protuberant downwards then if it had suffered
+  no refraction at all; and besides all this, the whole body of the Sun
+  appear'd to tremble or dance, and the edges or limb to be very ragged or
+  indented, undulating or waving, much in the manner of a flag in the
+  Wind.</p>
+
+  <p>This I have likewise often observ'd in a hot Sunshiny Summer's day,
+  that looking on an Object over a hot stone, or dry hot earth, I have
+  found the Object to be undulated or shaken, much after the same manner.
+  And if you look upon any remote Object through a <i>Telescope</i> (in a
+  hot Summer's day especially) you shall find it likewise to appear
+  tremulous. And further, if there chance to blow any wind, or that the air
+  between you and the Object be in a motion or current, whereby the parts
+  of it, both rarify'd and condens'd, are swiftly remov'd towards the right
+  or left, if then you observe the Horizontal ridge of a Hill far distant,
+  through a very good <i>Telescope</i>, you shall find it to wave much like
+  the Sea, and those waves will appear to pass the same way with the
+  wind.</p>
+
+  <p>From which, and many other Experiments, 'tis cleer that the lower
+  Region of the Air, especially that part of it which lieth neerest to the
+  Earth, has, for the most part, its constituent parcels variously
+  agitated, either by heat or winds, by the first of which, some of them
+  are made more rare, and so suffer a less refraction; others are
+  interwoven, either with ascending or descending vapours; the former of
+  which being more light, and so more rarify'd, have likewise a less
+  refraction; the latter being more heavie, and consequently more dense,
+  have a greater.</p>
+
+  <p>Now, because that heat and cold are equally diffus'd every way; and
+  that the further it is spread, the weaker it grows; hence it will follow,
+  that the most part of the under Region of the Air will be made up of
+  several kinds of <i>lentes</i>, some whereof will have the properties of
+  <i>Convex</i>, others of <i>Concave</i> <i>glasses</i>, which, that I may
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 8.
+</span>
+  the more intelligibly make out, we will suppose in the eighth
+  <i>Figure</i> of the 37. <i>Scheme</i>, that A represents an ascending
+  vapour, which, by reason of its being somewhat <i>Heterogeneous</i> to
+  the ambient Air, is thereby thrust into a kind of Globular form, not any
+  where terminated, but gradually finished, that is, it is most rarify'd in
+  the middle about A. somewhat more condens'd about BB, more then that
+  about CC; yet further, about DD, almost of the same density with the
+  ambient Air about EE;, and lastly, inclosed with the more dense Air FF,
+  so that from A, to FF, there is a continual increase of density. The
+  reason of which will be manifest, if we consider the rising vapour to be
+  much warmer then the ambient heavie Air; for by the coldness of the
+  ambient Air, the shell EE will be more refrigerated then DD, and that
+  then CC, which will be yet more then BB, and that more then
+  A; so that from F to A, there is a continual increase of heat, and
+  consequently of rarity; from whence it will necessarily follow, that the
+  Rays of light will be inflected or refracted in it, in the same manner as
+  they would be in a <i>Concave-glase</i>; for the Rays <i>GKI</i>,
+  <i>GKI</i> will be inflected by <i>GKH</i>, <i>GKH</i>, which will easily
+  follow from what I before explained concerning the inflection of the
+  <i>Atmosphere</i>.</p>
+
+  <p>On the other side, a descending vapour, or any part of the air
+  included by an ascending vapour, will exhibit the same effects with a
+  <i>Convex lens</i>; for, if we suppose, in the former Figure, the quite
+  contrary constitution to that last describ'd; that is, the ambient Air FF
+  being hotter then any part of that matter within any circle, therefore
+  the coldest part must necessarily be A, as being farthest remov'd from
+  the heat, all the intermediate spaces will be gradually discriminated by
+  the continuall mixture of heat and cold, so that it will be hotter at EE,
+  then DD, in DD then CC, in CC then BB, and in BB then A. From which, a
+  like refraction and condensation will follow, and consequently a lesser
+  or greater refraction, so that every included part will refract more then
+  the including, by which means the Rays, GKI, GKI, coming from a Starr, or
+  some remote Object, are so inflected, that they will again concurr and
+  meet, in the point M. By the interposition therefore of this desending
+  vapour the visible body of the Star, or other Object, is very much
+  augmented, as by the former it was diminished.</p>
+
+  <p>From the quick consecutions of these two, one after another, between
+  the Object and your eye, caused by their motion upwards or downwards,
+  proceeding from their levity or gravity, or to the right or left,
+  proceeding from the wind, a Starr may appear, now bigger, now less, then
+  really it would otherwise without them; and this is that property of a
+  Starr, which is commonly call'd twinkling, or scintillation.</p>
+
+  <p>The reason why a Star will now appear of one colour, now of another,
+  which for the most part happens when 'tis neer the Horizon, may very
+  easily be deduc'd from its appearing now in the middle of the vapour,
+  other whiles neer the edge; for if you look against the body of a Starr
+  with a <i>Telescope</i> that has a pretty deep <i>Convex</i> Eye-glass,
+  and so order it, that the Star may appear sometimes in one place, and
+  sometimes in another of it; you may perceive this or that particular
+  colour to be predominant in the apparent Figure of the Starr, according
+  as it is more or less remote from the middle of the <i>Lens</i>. This I
+  had here further explain'd, but that it does more properly belong to
+  another place.</p>
+
+  <p>I shall therefore onely add some few Queries, which the consideration
+  of these particulars hinted, and so finish this Section.</p>
+
+  <p>And the first I shall propound is, Whether there may not be made an
+  artificial transparent body of an exact Globular Figure that shall so
+  inflect or refract all the Rays, that, coming from one point, fall upon
+  any <i>Hemisphere</i> of it; that every one of them may meet on the
+  opposite side, and cross one another exactly in a point; and that it may
+  do the like also with all the Rays that, coming from a <i>lateral</i>
+  point, fall upon any other <i>Hemisphere</i>; for if so, there were to be
+  hoped a perfection of <i>Dioptricks</i>, and a
+  transmigration into heaven, even whil'st we remain here upon earth in the
+  flesh, and a descending or penetrating into the center and innermost
+  recesses of the earth, and all earthly bodies; nay, it would open not
+  onely a cranney, but a large window (as I may so speak) into the Shop of
+  Nature, whereby we might be enabled to see both the tools and operators,
+  and the very manner of the operation it self of Nature; this, could it be
+  effected, would as farr surpass all other kind of perspectives as the
+  vast extent of Heaven does the small point of the Earth, which distance
+  it would immediately remove, and unite them, as 'twere, into one, at
+  least, that there should appear no more distance between them then the
+  length of the Tube, into the ends of which these Glasses should be
+  inserted: Now, whether this may not be effected with parcels of Glass of
+  several densities, I have sometimes proceeded so farr as to doubt (though
+  in truth, as to the general, I have wholly despair'd of it) for I have
+  often observ'd in Optical Glasses a very great variety of the parts,
+  which are commonly called Veins; nay, some of them round enough (for they
+  are for the most part, drawn out into firings) to constitute a kind of
+  <i>lens</i>.</p>
+
+  <p>This I should further proceed to hope, had any one been so inquisitive
+  as to have found out the way of making any transparent body, either more
+  dense or more rare, for then it might be possible to compose a Globule
+  that should be more dense in the middle of it, then in any other part,
+  and to compose the whole bulk, so as that there should be a continual
+  gradual transition from one degree of density to another; such as should
+  be found requisite for the desired inflection of the
+  <i>transmigrating</i> Rays; but of this enough at present, because I may
+  say more of it when I set down my own Trials concerning the melioration
+  of <i>Dioptricks</i>, where I shall enumerate with how many several
+  substances I have made both <i>Microscopes</i>, and <i>Telescopes</i>,
+  and by what and how many, ways: Let such as have leisure and opportunity
+  farther consider it.</p>
+
+  <p>The next Quæry shall be, whether by the same collection of a more
+  dense body then the other, or at least, of the denser part of the other,
+  there might not be imagin'd a reason of the apparition of some new fix'd
+  Stars, as those in the Swan, <i>Cassiope's Charr</i>,
+  <i>Serpentarius</i>, <i>Piscis</i>, <i>Cetus</i>, &amp;c.</p>
+
+  <p>Thirdly, Whether it be possible to define the height of the
+  <i>Atmosphere</i> from this inflection of the Rays, or from the
+  Quicksilver Experiment of the rarifaction or extension of the Air.</p>
+
+  <p>Fourthly, Whether the disparity between the upper and under Air be not
+  sometimes so great, as to make a reflecting superficies; I have had
+  several Observations which seem to have proceeded from some such cause,
+  but it would be too long to relate and examine them. An Experiment, also
+  somewhat analogous to this, I have made with Salt-water and Fresh, which
+  two liquors, in most Positions, seem'd the same, and not to be separated
+  by any determinate superficies, which separating surface yet in some
+  other Positions did plainly appear.</p>
+
+  <p>And if so, Whether the reason of the equal bounding or <i>terminus</i>
+  of the under parts of the clouds may not proceed from this cause;
+  whether, secondly, the Reason of the apparition of
+  many Suns may not be found out, by considering how the Rays of the Sun
+  may so be reflected, as to describe a pretty true Image of the body, as
+  we find them from any regular Superficies. Whether also this may not be
+  found to cause the apparition of some of those <i>Parelii</i>, of
+  counterfeit Suns, which appear coloured, by refracting the Rays so, as to
+  make the body of the Sun appear in quite another place then really it is.
+  But of this more elsewhere.</p>
+
+  <p>5. Whether the <i>Phænomena</i> of the Clouds may not be made out by
+  this diversity of density in the upper and under parts of the Air, by
+  supposing the Air above them to be much lighter then they themselves are,
+  and they themselves to be yet lighter then that which is subjacent to
+  them, many of them seeming to be the same substance with the Cobwebs that
+  fly in the Air after a Fog.</p>
+
+  <p>Now that such a constitution of the Air and Clouds, if such there be,
+  may be sufficient to perform this effect, may be confirm'd by this
+  Experiment.</p>
+
+  <p>Make as strong a Solution of Salt as you are able, then filling a
+  Glass of some depth half full with it, fill the other half with fresh
+  Water, and poyse a little Glass-bubble, so as that it may sink pretty
+  quick in fresh Water, which take and put into the aforesaid Glass, and
+  you shall find it to sink till it comes towards the middle, where it will
+  remain fixt, without moving either upwards or downwards. And by a second
+  Experiment, of poising such a bubble in water, whose upper part is
+  warmer, and consequently lighter, then the under, which is colder and
+  heavier; the manner of which follows in this next Quæry, which is,</p>
+
+  <p>6. Whether the rarifaction and condensation of Water be not made after
+  the same manner, as those effects are produc'd in the Air by heat; for I
+  once pois'd a seal'd up Glass-bubble so exactly, that never so small an
+  addition would make it sink, and as small a detraction make it swim,
+  which suffering to rest in that Vessel of Water for some time, I alwayes
+  found it about noon to be at the bottom of the Water, and at night, and
+  in the morning, at the top: Imagining this to proceed from the
+  Rarifaction of the Water, caus'd by the heat, I made tryal, and found
+  most true; for I was able at any time, either to depress, or raise it, by
+  heat and cold; for if I let the Pipe stand for some time in cold water, I
+  could easily raise the Bubble from the bottom, whither I had a little
+  afore detruded it, by putting the same Pipe into warm Water. And this way
+  I have been able, for a very considerable time, to keep a Bubble so
+  poys'd in the Water, as that it should remain in the middle, and neither
+  sink, nor swim: For gently heating the upper part of the Pipe with a
+  Candle, Coal, or hot Iron, till I perceived the Bubble begin to descend,
+  then forbearing, I have observed it to descend to such or such a station,
+  and there to remain suspended for some hours, till the heat by degrees
+  were quite vanished, when it would again ascend to its former place. This
+  I have also often observed naturally performed by the heat of the Air,
+  which being able to rarifie the upper parts of the Water sooner then the
+  lower, by reason of its immediate contact, the heat of the Air
+  has sometimes so slowly increased, that I
+  have observed the Bubble to be some hours in passing between the top and
+  bottom.</p>
+
+  <p>7. Whether the appearance of the <i>Pike</i> of <i>Tenerif</i>, and
+  several other high Mountains, at so much greater a distance then seems to
+  agree with their respective heights, be not to be attributed to the
+  <i>Curvature</i> of the visual Ray, that is made by its passing obliquely
+  through so differingly <i>Dense</i> a Medium from the top to the eye very
+  far distant in the Horizon: For since we have already, I hope, made it
+  very probable, that there is such an <i>inflection</i> of the Rays by the
+  differing density of the parts of the Air; and since I have found, by
+  several Experiments made on places comparatively not very high, and have
+  yet found the pressure sustain'd by those parts of the Air at the top and
+  bottom, and also their differing Expansions very considerable: Insomuch
+  that I have found the pressure of the <i>Atmosphere</i> lighter at the
+  top of St. <i>Paul</i>'s Steeple in <i>London</i> (which is about two
+  hundred foot high) then at the bottom by a sixtieth or fiftieth part, and
+  the expansion at the top greater then that at the bottom by neer about so
+  much also; for the <i>Mercurial Cylinder</i> at the bottom was about 39.
+  inches, and at the top half an inch lower; the Air also included in the
+  Weather-glass, that at the bottom fill'd only 155. spaces, at the top
+  fill'd 158. though the heat at the top and bottom was found exactly the
+  same with a scal'd <i>Thermometer</i>: I think it very rational to
+  suppose, that the greatest Curvature of the Rays is made nearest the
+  Earth, and that the inflection of the Rays, above 3. or 4. miles upwards,
+  is very inconsiderable, and therefore that by this means such
+  calculations of the height of Mountains, as are made from the distance
+  they are visible in the Horizon, from the supposal that that Ray is a
+  straight Line (that from the top of the Mountain is, as 'twere, a Tangent
+  to the Horizon whence it is seen) which really is a <i>Curve</i>, is very
+  erroneous. Whence, I suppose, proceeds the reason of the exceedingly
+  differing Opinions and Assertions of several Authors, about the height of
+  several very high Hills.</p>
+
+  <p>8. Whether this Inflection of the Air will not very much alter the
+  supposed distances of the Planets, which seem to have a very great
+  dependence upon the Hypothetical refraction or inflection of the Air, and
+  that refraction upon the hypothetical height and density of the Air: For
+  since (as I hope) I have here shewn the Air to be quite otherwise then
+  has been hitherto suppos'd, by manifesting it to be, both of a vast, at
+  least an uncertain, height, and of an unconstant and irregular density;
+  It must necessarily follow, that its inflection must be varied
+  accordingly: And therefore we may hence learn, upon what sure grounds all
+  the Astronomers hitherto have built, who have calculated the distance of
+  the Planets from their Horizontal <i>Parallax</i>; for since the
+  Refraction and <i>Parallax</i> are so nearly ally'd, that the one cannot
+  be known without the other, especially by any wayes that have been yet
+  attempted, how uncertain must the <i>Parallax</i> be, when the Refraction
+  is unknown? And how easie is it for Astronomers to assign what distance
+  they please to the Planets, and defend them, when they have such a
+  curious <i>subterfuge</i> as that of Refraction, wherein a very little
+  variation will allow them liberty enough to place the Celestial Bodies at
+  what distance they please.</p>
+
+  <p>If therefore we would come to any certainty in this point, we must go
+  other wayes to work; and as I have here examined the height and
+  refractive property of the Air by other wayes then are usual, so must we
+  find the Parallax of the Planets by wayes not yet practiced; and to this
+  end, I cannot imagine any better way, then the Observations of them by
+  two persons at very far distant parts of the Earth, that lye as neer as
+  may be under the same Meridian, or Degree of longitude, but differing as
+  much in latitude, as there can be places conveniently found: These two
+  persons, at certain appointed times, should (as near as could be) both at
+  the same time, observe the way of the <i>Moon</i>, <i>Mars</i>,
+  <i>Venus</i>, <i>Jupiter</i>, and <i>Saturn</i>, amongst the fixt Stars,
+  with a good large <i>Telescope</i>, and making little Iconismes, or
+  pictures, of the small fixed Stars, that appear to each of them to lye in
+  or near the way of the Center of the Planet, and the exact measure of the
+  apparent Diameter; from the comparing of such Observations together, we
+  might certainly know the true distance, or Parallax, of the Planet. And
+  having any one true Parallax of these Planets, we might very easily have
+  the other by their apparent Diameters, which the <i>Telescope</i>
+  likewise affords us very accurately. And thence their motions might be
+  much better known, and their Theories more exactly regulated. And for
+  this purpose I know not any one place more convenient for such an
+  Observation to be made in, then in the Island of St. <i>Helena</i>, upon
+  the Coast of <i>Africk</i>, which lyes about sixteen degrees to the
+  Southwards of the Line, and is very near, according to the latest
+  Geographical Maps, in the same Meridian with <i>London</i>; for though
+  they may not perhaps lye exactly in the same, yet their Observations,
+  being ordered according to what I shall anon shew, it will not be
+  difficult to find the true distance of the Planet. But were they both
+  under the same Meridian, it would be much better.</p>
+
+  <p>And because Observations may be much easier, and more accurately made
+  with good <i>Telescopes</i>, then with any other Instruments, it will
+  not, I suppose, seem impertinent to explain a little what wayes I judge
+  most fit and convenient for that particular. Such therefore as shall be
+  the Observators for this purpose, should be furnished with the best
+  <i>Telescopes</i> that can be had, the longer the better and more exact
+  will their Observations be, though they are somewhat the more difficultly
+  manag'd. These should be fitted with a <i>Rete</i>, or divided Scale,
+  plac'd at such a distance within the Eye-glass, that they may be
+  distinctly seen, which should be the measures of minutes and seconds; by
+  this Instrument each Observator should, at certain prefixt times, observe
+  the Moon, or other Planet, in, or very near, the Meridian; and because it
+  may be very difficult to find two convenient stations that will happen to
+  be just under the same Meridian, they shall, each of them, observe the
+  way of the Planet, both for an hour before, and an hour after, it arrive
+  at the Meridian; and by a line, or stroke, amongst the small fixed Stars,
+  they shall denote out the way that each of them observ'd the Center of
+  the Planet to be mov'd in for those two hours: These Observations each of
+  them shall repeat for many dayes together, that both it may happen, that
+  both of them may sometimes make their Observations
+  together, and that from divers Experiments we may be the better assured
+  of what certainty and exactness such kind of Observations are like to
+  prove. And because many of the Stars which may happen to come within the
+  compass of such an <i>Iconism</i>, or Map, may be such as are only
+  visible through a good <i>Telescope</i>, whose Positions perhaps have not
+  been noted, nor their longitudes, or latitudes, any where remarked;
+  therefore each Observator should indeavour to insert some fixt Star,
+  whose longitude, and latitude, is known; or with his <i>Telescope</i> he
+  shall find the Position of some notable <i>telescopical</i> Star,
+  inserted in his Map, to some known fixt Star, whose place in the
+  <i>Zodiack</i> is well defin'd.</p>
+
+  <p>Having by this means found the true distance of the Moon, and having
+  observed well the <i>apparent Diameter</i> of it at that time with a good
+  <i>Telescope</i>, it is easie enough, by one single Observation of the
+  apparent Diameter of the Moon with a good Glass, to determine her
+  distances in any other part of her <i>Orbit</i>, or <i>Dragon</i>, and
+  consequently, some few Observations will tell us, whether she be mov'd in
+  an <i>Ellipsis</i>, (which, by the way, may also be found, even now,
+  though I think we are yet ignorant of her true distance) and next (which
+  without such Observations, I think, we shall not be sure of) we may know
+  exactly the bigness of that <i>Ellipsis</i>, or Circle, and her true
+  velocity in each part, and thereby be much the better inabled to find out
+  the true cause of all her Motions. And though, even now also, we may, by
+  such Observations in one station, as here at <i>London</i>, observe the
+  <i>apparent Diameter</i> and motion of the Moon in her <i>Dragon</i>, and
+  consequently be inabled to make a better ghess at the <i>Species</i> or
+  kind of Curve, in which she is mov'd, that is, whether it be sphærical,
+  or <i>elliptical</i>, or neither, and with what proportional velocities
+  she is carried in that Curve; yet till her true <i>Parallax</i> be known,
+  we cannot determine either.</p>
+
+  <p>Next, for the true distance of the Sun, the best way will be, by
+  accurate Observations, made in both these forementioned stations, of some
+  convenient Eclipse of the Sun, many of which may so happen, as to be seen
+  by both; for the <i>Penumbra</i> of the Moon may, if she be sixty
+  Semidiameters distant from the Earth, and the Sun above seven thousand,
+  extend to about seventy degrees on the Earth, and consequently be seen by
+  Observators as far distant as <i>London</i>, and St. <i>Helena</i>, which
+  are not full sixty nine degrees distant. And this would much more
+  accurately, then any way that has been yet used, determine the Parallax,
+  and distance, of the Sun; for as for the Horizontal Parallax I have
+  already shewn it sufficiently uncertain; nor is the way of finding it by
+  the Eclipse of the Moon any other then hypothetical; and that by the
+  difference of the true and apparent quadrature of the Moon is not less
+  uncertain, witness their Deductions from it, who have made use of it; for
+  <i>Vendeline</i> puts that difference to be but 4'.30". whence he deduces
+  a vast distance of the Sun, as I have before shewn. <i>Ricciolo</i> makes
+  it full 30'.00. but <i>Reinoldus</i>, and <i>Kircher</i>, no less then
+  three degrees. And no wonder, for if we examine the <i>Theory</i>, we
+  shall find it so complicated with uncertainties.</p>
+
+  <p>First, From the irregular surface of the Moon, and from several
+  Parallaxes, that unless the <i>Dichotomy</i> happen in the
+  <i>Nonagesimus</i> of the <i>Ecliptick</i>, and that in the Meridian,
+  <i>&amp;c.</i> all which happen so very seldom, that it is almost
+  impossible to make them otherwise then uncertainly. Besides, we are not
+  yet certain, but that there may be somewhat about the Moon
+  <i>analogus</i> to the Air about the Earth, which may cause a refraction
+  of the light of the Sun, and consequently make a great difference in the
+  apparent <i>dichotomy</i> of the Moon. Their way indeed is very rational
+  and ingenious; and such as is much to be preferred before the way by the
+  Horizontal Parallax, could all the uncertainties be remov'd, and were the
+  true distance of the Moon known.</p>
+
+  <p>But because we find by the Experiments of <i>Vendiline</i>,
+  <i>Reinoldus</i>, &amp;c. that Observations of this kind are very
+  uncertain also: It were to be wisht, that such kind of Observations, made
+  at two very distant stations, were promoted. And it is so much the more
+  desirable, because, from what I have now shewn of the nature of the Air,
+  it is evident, that the refraction may be very much greater then all the
+  Astronomers hitherto have imagined it: And consequently, that the
+  distance of the Moon, and other Planets, may be much lesse then what they
+  have hitherto made it.</p>
+
+  <p>For first, this Inflection, I have here propounded, will allow the
+  shadow of the Earth to be much shorter then it can be made by the other
+  <i>Hypothesis</i> of refraction, and consequently, the Moon will not
+  suffer an Eclipse, unless it comes very much nearer the Earth then the
+  Astronomers hitherto have supposed it.</p>
+
+  <p>Secondly, There will not in this <i>Hypothesis</i> be any other shadow
+  of the Earth, such as <i>Kepler</i> supposes, and calls the
+  <i>Penumbra</i>, which is the shadow of the refracting <i>Atmosphere</i>;
+  for the bending of the Rays being altogether caus'd by <i>Inflection</i>,
+  as I have already shewn, all that part which is ascribed by
+  <i>Kepler</i>, and others after him, to the <i>Penumbra</i>, or dark
+  part, which is without the <i>umbra terræ</i>, does clear vanish; for in
+  this <i>Hypothesis</i> there is no refracting surface of the Air, and
+<span class="sidenote">
+<a href="images/scheme-37.png" target="_blank"><i>Schem.</i> 37.</a><br /><i>Fig.</i> 9.
+</span>
+  consequently there can be no shadows, such as appear in the ninth Figure
+  of the 37. <i>Scheme</i>, where let ABCD represent the Earth, and EFGH
+  the <i>Atmosphere</i>, which according to <i>Keplers</i> supposition, is
+  like a Sphære of Water terminated with an exact surface EFGH, let the
+  lines MF, LB, ID, KH, represent the Rays of the Sun; 'tis manifest, that
+  all the Rayes between LB, and ID, will be reflected by the surface of the
+  Earth BAD, and consequently, the conical space BOD would be dark and
+  obscure; but, say the followers of <i>Kepler</i>, the Rays between MF,
+  and LB, and between ID, and KH, falling on the <i>Atmosphere</i>, are
+  refracted, both at their ingress and egress out of the <i>Atmosphere</i>,
+  nearer towards the Axis of the sphærical shadow CO, and consequently,
+  inlighten a great part of that former dark Cone, and shorten, and
+  contract, its top to N. And because of this Reflection of these Rays, say
+  they, there is superinduc'd another shell of a dark Cone FPH, whose Apex
+  P is yet further distant from the Earth: By this <i>Penumbra</i>, say
+  they, the Moon is Eclipsed, for it alwayes passes between
+  the lines 12, and 34.</p>
+
+  <p>To which I say, That if the Air be such, as I have newly shewn it to
+  be, and consequently cause such an inflection of the Rays that fall into
+  it, those dark <i>Penumbra's</i> FYZQ, HXVT, and ORPS, will all vanish.
+  For if we suppose the Air indefinitely extended, and to be no where
+  bounded with a determinate refracting surface, as I have shewn it
+  uncapable of having, from the nature of it; it will follow, that the Moon
+  will no where be totally obscured, but when it is below the Apex N, of
+  the dark blunt Cone of the Earth's shadow: Now, from the supposition,
+  that the Sun is distant about seven thousand Diameters, the point N,
+  according to calculation, being not above twenty five terrestrial
+  Semidiameters from the Center of the Earth: It follows, that whensoever
+  the Moon eclipsed is totally darkned, without affording any kind of
+  light, it must be within twenty five Semidiameters of the Earth, and
+  consequently much lower then any Astronomers have hitherto put it.</p>
+
+  <p>This will seem much more consonant to the rest of the secundary
+  Planets; for the highest of <i>Jupiter's</i> Moons is between twenty and
+  thirty <i>Jovial Semidiameters</i> distant from the Center of
+  <i>Jupiter</i>; and the Moons of <i>Saturn</i> much about the same number
+  of <i>Saturnial Semidiameters</i> from the Center of that Planet.</p>
+
+  <p>But these are but conjectures also, and must be determin'd by such
+  kind of Observations as I have newly mention'd.</p>
+
+  <p>Nor will it be difficult, by this <i>Hypothesis</i>, to salve all the
+  appearances of Eclipses of the Moon, for in this <i>Hypothesis</i> also,
+  there will be on each side of the shadow of the Earth, a <i>Penumbra</i>,
+  not caus'd by the Refraction of the Air, as in the <i>Hypothesis</i> of
+  <i>Kepler</i>; but by the faint inlightning of it by the Sun: For if, in
+  the sixth Figure, we suppose ESQ, and GSR, to be the Rays that terminate
+  the shadow from either side of the Earth; ESQ coming from the upper limb
+  of the Sun, and GSR from the under; it will follow, that the shadow of
+  the Earth, within those Rays, that is, the Cone GSE, will be totally
+  dark. But the Sun being not a point, but a large <i>area</i> of light,
+  there will be a secondary dark Cone of shadow EPG, which will be caus'd
+  by the earth's hindring part of the Rays of the Sun from falling on the
+  parts GPR, and EPQ, of which halved shadow, or <i>Penumbra</i>, that part
+  will appear brightest which lyes nearest the terminating Rayes GP, and
+  EP, and those darker that lye nearest to GS, and ES: when therefore the
+  Moon appears quite dark in the middle of the Eclipse, she must be below
+  S, that is, between S and F; when she appears lighter near the middle of
+  the Eclipse, she must pass some where between RQ and S; and when she is
+  alike light through the whole Eclypse, she must pass between RQ, and
+  P.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLIX" id="obsLIX">LIX</a>. <i>Of multitudes of small </i>Stars<i> discoverable by the
+</i>Telescope<i>.</i></h3>
+
+  <p>Having, in the last Observation, premis'd some particulars observable
+  in the <i>medium</i>, through which we must look upon
+  <i>C&#339;lestial</i> Objects, I shall here add one Observation of the
+  Bodies themselves; and for a <i>specimen</i> I have made choice of the
+  <i>Pleiades</i>, or seven Stars, commonly so called (though in our time
+  and Climate there appear no more then six to the naked eye) and this I
+  did the rather, because the deservedly famous <i>Galileo</i>, having
+  publisht a Picture of this <i>Asterisme</i>, was able, it seems, with his
+  Glass to discover no more then thirty six, whereas with a pretty good
+<span class="sidenote">
+<a href="images/scheme-38.png" target="_blank"><i>Schem.</i> 38.</a>
+</span>
+  twelve foot <i>Telescope</i>, by which I drew this 38 <i>Iconism</i>, I
+  could very plainly discover seventy eight, placed in the order they are
+  ranged in the Figure, and of as many differing Magnitudes as the
+  <i>Asterisks</i>, wherewith they are Marked, do specifie; there being no
+  less then fourteen several Magnitudes of those Stars, which are compris'd
+  within the draught, the biggest whereof is not accounted greater then one
+  of the third Magnitude; and indeed that account is much too big, if it be
+  compared with other Stars of the third Magnitude, especially by the help
+  of a <i>Telescope</i>; for then by it may be perceiv'd, that its
+  splendor, to the naked eye, may be somewhat augmented by the three little
+  Stars immediately above it, which are near adjoyning to it. The
+  <i>Telescope</i> also discovers a great variety, even in the bigness of
+  those, commonly reckon'd, of the first, second, third, fourth, fifth, and
+  sixth Magnitude; so that should they be distinguish'd thereby, those six
+  Magnitudes would, at least, afford no less then thrice that number of
+  Magnitudes, plainly enough distinguishable by their Magnitude, and
+  brightness; so that a good twelve foot Glass would afford us no less then
+  twenty five several Magnitudes. Nor are these all, but a longer Glass
+  does yet further, both more nicely distinguish the Magnitudes of those
+  already noted, and also discover several other of smaller Magnitudes, not
+  discernable by the twelve foot Glass: Thus have I been able, with a good
+  thirty six foot Glass, to discover many more Stars in the <i>Pleiades</i>
+  then are here delineated, and those of three or four distinct Magnitudes
+  less then any of those spots of the fourteenth Magnitude. And by the
+  twinkling of divers other places of this <i>Asterisme</i>, when the Sky
+  was very clear, I am apt to think, that with longer Glasses, or such as
+  would bear a bigger <i>aperture</i>, there might be discovered multitudes
+  of other small Stars, yet inconspicuous. And indeed, for the discovery of
+  small Stars, the bigger the <i>aperture</i> be, the better adapted is the
+  Glass; for though perhaps it does make the several specks more radiant,
+  and glaring, yet by that means, uniting more Rays very near to one point,
+  it does make many of those radiant points conspicuous,   which, by putting on a less <i>aperture</i>, may be found to vanish; and
+  therefore, both for the discovery of the fixt Star, and for finding the
+  <i>Satellites</i> of <i>Jupiter</i>, before it be out of the day, or
+  twilight, I alwayes leave the Object-glass as clear without any
+  <i>aperture</i> as I can, and have thereby been able to discover the
+  <i>Satellites</i> a long while before; I was able to discern them, when
+  the smaller <i>apertures</i> were put on; and at other times, to see
+  multitudes of other smaller Stars, which a smaller <i>aperture</i> makes
+  to disappear.</p>
+
+  <p>In that notable <i>Asterism</i> also of the Sword of <i>Orion</i>,
+  where the ingenious Monsieur <i>Hugens van Zulichem</i> has discovered
+  only three little Stars in a cluster, I have with a thirty six foot
+  Glass, without any <i>aperture</i> (the breadth of the Glass being about
+  some three inches and a half) discover'd five, and the twinkling of
+  divers others up and down in divers parts of that small milky Cloud.</p>
+
+  <p>So that 'tis not unlikely, but that the meliorating of
+  <i>Telescopes</i> will afford as great a variety of new Discoveries in
+  the Heavens, as better <i>Microscopes</i> would among small terrestrial
+  Bodies, and both would give us infinite cause, more and more to admire
+  the omnipotence of the Creator.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h3>Observ. <a name="obsLX" id="obsLX">LX</a>. <i>Of the </i>Moon<i>.</i></h3>
+
+  <p>Having a pretty large corner of the Plate for the seven Starrs, void,
+  for the filling it up, I have added one small <i>Specimen</i> of the
+  appearance of the parts of the Moon, by describing a small spot of it,
+  which, though taken notice of, both by the Excellent <i>Hevelius</i>, and
+  called <i>Mons Olympus</i> (though I think somewhat improperly, being
+<span class="sidenote">
+<a href="images/scheme-38.png" target="_blank"><i>Schem.</i> 38.</a><br /><i>Fig.</i> X, <i>&amp;c</i>.
+</span>
+  rather a vale) and represented by the Figure X. of the 38. <i>Scheme</i>,
+  and also by the Learn'd <i>Ricciolus</i>, who calls it <i>Hipparchus</i>,
+  and describes it by the Figure Y, yet how far short both of them come of
+  the truth, may be somewhat perceiv'd by the draught, which I have here
+  added of it, in the Figure Z, (which I drew by a thirty foot Glass, in
+  <i>October</i> 1664. just before the Moon was half inlightned) but much
+  better by the Reader's diligently observing it himself, at a convenient
+  time, with a Glass of that length, and much better yet with one of
+  threescore foot long, for through these it appears a very spacious Vale,
+  incompassed with a ridge of Hills, not very high in comparison of many
+  other in the Moon, nor yet very steep. The Vale it self ABCD, is much of
+  the figure of a Pear, and from several appearances of it, seems to be
+  some very fruitful place, that is, to have its surface all covered over
+  with some kinds of vegetable substances; for in all positions of the
+  light on it, it seems to give a much fainter reflection then the more
+  barren tops of the incompassing Hills, and those a much fainter then
+  divers other cragged, chalky, or rocky Mountains of the Moon. So that I
+  am not unapt to think, that the Vale may have
+  Vegetables <i>analogus</i> to our Grass, Shrubs, and Trees; and most of
+  these incompassing Hills may be covered with so thin a vegetable Coat, as
+  we may observe the Hills with us to be, such as the short Sheep pasture
+  which covers the Hills of <i>Salisbury</i> Plains.</p>
+
+  <p>Up and down in several parts of this place here describ'd (as there
+  are multitudes in other places all over the surface of the Moon) may be
+  perceived several kinds of pits, which are shap'd almost like a dish,
+  some bigger, some less, some shallower, some deeper, that is, they seem
+  to be a hollow <i>Hemisphere</i>, incompassed with a round rising bank,
+  as if the substance in the middle had been digg'd up, and thrown on
+  either side. These seem to me to have been the effects of some motions
+  within the body of the Moon, <i>analogus</i> to our Earthquakes, by the
+  eruption of which, as it has thrown up a brim, or ridge, round about,
+  higher then the Ambient surface of the Moon, so has it left a hole, or
+  depression, in the middle, proportionably lower; divers places resembling
+  some of these, I have observ'd here in <i>England</i>, on the tops of
+  some Hills, which might have been caus'd by some Earthquake in the
+  younger dayes of the world. But that which does most incline me to this
+  belief, is, first, the generality and diversity of the Magnitude of these
+  pits all over the body of the Moon. Next, the two experimental wayes, by
+  which I have made a representation of them.</p>
+
+  <p>The first was with a very soft and well temper'd mixture of
+  Tobacco-pipe clay and Water, into which, if I let fall any heavy body, as
+  a Bullet, it would throw up the mixture round the place, which for a
+  while would make a representation, not unlike these of the Moon; but
+  considering the state and condition of the Moon, there seems not any
+  probability to imagine, that it should proceed from any cause
+  <i>analogus</i> to this; for it would be difficult to imagine whence
+  those bodies should come; and next, how the substance of the Moon should
+  be so soft; but if a Bubble be blown under the surface of it, and
+  suffer'd to rise, and break; or if a Bullet, or other body, sunk in it,
+  be pull'd out from it, these departing bodies leave an impression on the
+  surface of the mixture, exactly like these of the Moon, save that these
+  also quickly subside and vanish. But the second, and most notable,
+  representation was, what I observ'd in a pot of boyling Alabaster, for
+  there that powder being by the eruption of vapours reduc'd to a kind of
+  fluid consistence, if, whil'st it boyls, it be gently remov'd besides the
+  fire, the Alabaster presently ceasing to boyl, the whole surface,
+  especially that where some of the last Bubbles have risen, will appear
+  all over covered with small pits, exactly shap'd like these of the Moon,
+  and by holding a lighted Candle in a large dark Room, in divers positions
+  to this surface, you may exactly represent all the <i>Phænomena</i> of
+  these pits in the Moon, according as they are more or less inlightned by
+  the Sun.</p>
+
+  <p>And that there may have been in the Moon some such motion as this,
+  which may have made these pits, will seem the more probable, if we
+  suppose it like our Earth, for the Earthquakes here with us seem to
+  proceed from some such cause, as the boyling of the pot of Alabaster,
+  there seeming to be generated in the Earth
+  from some subterraneous fires, or heat, great quantities of vapours, that
+  is, of expanded aerial substances, which not presently finding a passage
+  through the ambient parts of the Earth, do, as they are increased by the
+  supplying and generating principles, and thereby (having not sufficient
+  room to expand themselves) extreamly condens'd, at last overpower, with
+  their <i>elastick</i> properties, the resistence of the incompassing
+  Earth, and lifting it up, or cleaving it, and so shattering of the parts
+  of the Earth above it, do at length, where they find the parts of the
+  Earth above them more loose, make their way upwards, and carrying a great
+  part of the Earth before them, not only raise a small brim round about
+  the place, out of which they break, but for the most part considerable
+  high Hills and Mountains, and when they break from under the Sea, divers
+  times, mountainous Islands; this seems confirm'd by the <i>Vulcans</i> in
+  several places of the Earth, the mouths of which, for the most part, are
+  incompassed with a Hill of a considerable height, and the tops of those
+  Hills, or Mountains, are usually shap'd very much like these pits, or
+  dishes, of the Moon: Instances of this we have in the descriptions of
+  <i>Ætna</i> in <i>Sicily</i>, of <i>Hecla</i> in <i>Iceland</i>, of
+  <i>Tenerif</i> in the <i>Canaries</i>, of the several <i>Vulcans</i> in
+  <i>New-Spain</i>, describ'd by <i>Gage</i>, and more especially in the
+  eruption of late years in one of the <i>Canary</i> Islands. In all of
+  which there is not only a considerable high Hill raised about the mouth
+  of the <i>Vulcan</i>, but, like the spots of the Moon, the top of those
+  Hills are like a dish, or bason. And indeed, if one attentively consider
+  the nature of the thing, one may find sufficient reason to judge, that it
+  cannot be otherwise; for these eruptions, whether of fire, or smoak,
+  alwayes raysing great quantities of Earth before them, must necessarily,
+  by the fall of those parts on either side, raise very considerable
+  heaps.</p>
+
+  <p>Now, both from the figures of them, and from several other
+  circumstances; these pits in the Moon seem to have been generated much
+  after the same manner that the holes in Alabaster, and the <i>Vulcans</i>
+  of the Earth are made. For first, it is not improbable, but that the
+  substance of the Moon may be very much like that of our Earth, that is,
+  may consist of an earthy, sandy, or rocky substance, in several of its
+  superficial parts, which parts being agitated, undermin'd, or heav'd up,
+  by eruptions of vapours, may naturally be thrown into the same kind of
+  figured holes, as the small dust, or powder of Alabaster. Next, it is not
+  improbable, but that there may be generated, within the body of the Moon,
+  divers such kind of internal fires and heats, as may produce such
+  Exhalations; for since we can plainly enough discover with a
+  <i>Telescope</i>, that there are multitudes of such kind of eruptions in
+  the body of the Sun it self, which is accounted the most noble Ætherial
+  body, certainly we need not be much scandaliz'd at such kind of
+  alterations, or corruptions, in the body of this lower and less
+  considerable part of the universe, the Moon, which is only secundary, or
+  attendant, on the bigger, and more considerable body of the Earth.
+  Thirdly, 'tis not unlikely, but that supposing such a sandy or mouldring
+  substance to be there found, and supposing also a
+  possibility of the generation of the internal <i>elastical</i> body
+  (whether you will call it air or vapours) 'tis not unlikely, I say, but
+  that there is in the Moon a principle of gravitation, such as in the
+  Earth. And to make this probable, I think, we need no better Argument,
+  then the roundness, or globular Figure of the body of the Moon it self,
+  which we may perceive very plainly by the <i>Telescope</i>, to be (bating
+  the small inequality of the Hills and Vales in it, which are all of them
+  likewise shap'd, or levelled, as it were, to answer to the center of the
+  Moons body) perfectly of a Sphærical figure, that is, all the parts of it
+  are so rang'd (bating the comparitively small ruggedness of the Hills and
+  Dales) that the outmost bounds of them are equally distant from the
+  Center of the Moon, and consequently, it is exceedingly probable also,
+  that they are equidistant from the Center of gravitation; and indeed, the
+  figure of the superficial parts of the Moon are so exactly shap'd,
+  according as they should be, supposing it had a gravitating principle as
+  the Earth has, that even the figure of those parts themselves is of
+  sufficient efficacy to make the gravitation, and the other two
+  suppositions probable: so that the other suppositions may be rather
+  prov'd by this considerable Circumstance, or Observation, then this
+  suppos'd Explication can by them; for he that shall attentively observe
+  with an excellent <i>Telescope</i>, how all the Circumstances, notable in
+  the shape of the superficial parts, are, as it were, exactly adapted to
+  suit with such a principle, will, if he well considers the usual method
+  of Nature in its other proceedings, find abundant argument to believe it
+  to have really there also such a principle; for I could never observe,
+  among all the mountainous or prominent parts of the Moon (whereof there
+  is a huge variety) that any one part of it was plac'd in such a manner,
+  that if there should be a gravitating, or attracting principle in the
+  body of the Moon, it would make that part to fall, or be mov'd out of its
+  visible posture. Next, the shape and position of the parts is such, that
+  they all seem put into those very shapes they are in by a gravitating
+  power: For first, there are but very few clifts, or very steep
+  declivities in the ascent of these Mountains; for besides those
+  Mountains, which are by <i>Hevelius</i> call'd the <i>Apennine</i>
+  Mountains, and some other, which seem to border on the Seas of the Moon,
+  and those only upon one side, as is common also in those Hills that are
+  here on the Earth; there are very few that seem to have very steep
+  ascents, but, for the most part, they are made very round, and much
+  resemble the make of the Hills and Mountains also of the Earth; this may
+  be partly perceived by the Hills incompassing this Vale, which I have
+  here describ'd; and as on the Earth also, the middlemost of these Hills
+  seems the highest, so is it obvious also, through a good
+  <i>Telescope</i>, in those of the Moon; the Vales also in many are much
+  shap'd like those of the Earth, and I am apt to think, that could we look
+  upon the Earth from the Moon, with a good <i>Telescope</i>, we might
+  easily enough perceive its surface to be very much like that of the
+  Moon.</p>
+
+  <p>Now whereas in this small draught, (as there would be multitudes if
+  the whole Moon were drawn after this manner) there are several little
+  Ebullitions, or Dishes, even in the Vales
+  themselves, and in the incompassing Hills also; this will, from this
+  supposition, (which I have, I think, upon very good reason taken) be
+  exceeding easily explicable; for, as I have several times also observ'd,
+  in the surface of Alabaster so ordered, as I before describ'd, so may the
+  later eruptions of vapours be even in the middle, or on the edges of the
+  former; and other succeeding these also in time may be in the middle or
+  edges of these, <i>&amp;c.</i> of which there are Instances enough in
+  divers parts of the body of the Moon, and by a boyling pot of Alabaster
+  will be sufficiently exemplifi'd.</p>
+
+  <p>To conclude therefore, it being very probable, that the Moon has a
+  principle of gravitation, it affords an excellent distinguishing Instance
+  in the search after the cause of gravitation, or attraction, to hint,
+  that it does not depend upon the diurnal or turbinated motion of the
+  Earth, as some have somewhat inconsiderately supposed and affirmed it to
+  do; for if the Moon has an attractive principle, whereby it is not only
+  shap'd round, but does firmly contain and hold all its parts united,
+  though many of them seem as loose as the sand on the Earth, and that the
+  Moon is not mov'd about its Center; then certainly the turbination cannot
+  be the cause of the attraction of the Earth, and therefore some other
+  principle must be thought of, that will agree with all the secundary as
+  well as primary Planets. But this, I confess, is but a probability, and
+  not a demonstration, which (from any Observation yet made) it seems
+  hardly capable of, though how successful future indeavours (promoted by
+  the meliorating of Glasses, and observing particular circumstances) may
+  be in this, or any other, kind, must be with patience expected.</p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h2><i>FINIS.</i></h2>
+
+<hr class="full" />
+
+  <div class="figcenter" style="width:60%;">
+      <a href="images/rule-06.png"><img width="100%" src="images/rule-06.png"
+      alt="Decorative rule" /></a>
+  </div>
+  <br clear="all" />
+
+<h2>THE TABLE.</h2>
+
+  <p>Observat. <a href="#obsI">1</a>. Of the point of a Needle.</p>
+
+  <p><i>A Description of it: what other Bodies have the sharpest points: of
+  the ruggedness of polisht Metal. A description of a printed point. Of
+  very small writing, and the use of it for secret intelligence: the cause
+  of the coursness of printed lines and points.</i></p>
+
+  <p>Observ. <a href="#obsII">2</a>. Of the Edge of a Razor.</p>
+
+  <p><i>A description of it: the causes of its roughness: of the roughness
+  of very well polisht Optick Glasses.</i>.</p>
+
+  <p>Obser. <a href="#obsIII">3</a>. Of fine Lawn.</p>
+
+  <p><i>A description of it: A silken Flax mention'd, an attempt to
+  explicate the </i>Phænomena<i> of it, with a conjecture at the cause of
+  the gloss of Silk.</i></p>
+
+  <p>Observ. <a href="#obsIV">4</a>. Of Tabby.</p>
+
+  <p><i>A short description of it. A conjecture about the reason why Silk
+  is so susceptible of vivid colours: and why Flax and Hair is not. A
+  conjecture, that it way perhaps be possible to spin a kind of artificial
+  Silk, out of some glutinous substance that may equalize natural
+  Silk.</i></p>
+
+  <p>Observ. <a href="#obsV">5</a>. Of water'd Silks.</p>
+
+  <p><i>The great unaccurateness of artificial works. A description of a
+  piece of water'd Silk; an Explication of the cause of the
+  </i>Phænomena<i>: the way by which that operation is perform'd: some
+  other </i>Phænomena<i> mention'd depending on the same cause.</i></p>
+
+  <p>Observ. <a href="#obsVI">6</a>. Of Glass-Canes.</p>
+
+  <p><i>The exceeding smallness of some of these Bodies. By what means the
+  hollowness of these small pipes was discover'd: several </i>Phænomena<i>
+  of it mention'd. An attempt to explicate them from the congruity and
+  incongruity of Bodies: what those proprieties are. A hypothetical
+  explication of fluidity: of the fluidity of the air, and several other
+  </i>Phænomena<i> of it: of congruity &amp; incongruity; illustrated with
+  several Experiments: what effects may be ascrib'd to these properties: an
+  explication of the roundness of the surface of fluid Bodies: how the
+  ingress of fluid bodies into a small hole of an heterogenious body is
+  hindred by incongruity; a multitude of </i>Phænomena<i> explicable
+  hereby. Several Quæries propounded; 1. Concerning the propagation of
+  light through differing mediums. 2. Concerning Gravity. 3. Concerning the
+  roundness of the Sun, Moon, and Planets. 4. Concerning the roundness of
+  Fruits, Stones, and divers artificial Bodies. His Highness Prince
+  </i>Rupert's<i> way of making Shot. Of the roundness of Hail. Of the
+  grain of </i>Kettering<i> Stone, and of the Sparks of fire. 5. Concerning
+  springiness and tenacity. 6. Concerning the original of Fountains;
+  several Histories and Experiments relating thereto. 7. Concerning the
+  dissolution of Bodies in Liquors. 8. Concerning the universality of this
+  Principle: what method was taken in making and applying experiments. The
+  explication of filtration, and several
+  other </i>Phænomena<i>; such as the motion of Bodies on the surface of
+  Liquors; several Experiments mention'd to this purpose. Of the height to
+  which the water may rise in these Pipes; and a conjecture about the
+  juices of Vegetables, &amp; the use of their pores. A further explication
+  of Congruity: And an attempt of solving the </i>Phænomena<i> of the
+  strange Experiment of the suspension of the </i>Mercury<i> at a much
+  greater height then thirty inches. The efficacy of immediate contact, and
+  the reason of it.</i></p>
+
+  <p>Observ. <a href="#obsVII">7</a>. Of Glass drops.</p>
+
+  <p><i>Several Experiments made with these small Bodies. The manner of the
+  breaking and flawing of them, explicated by Figures. What other bodies
+  will be flawed much in the same manner: so other tryals, and a
+  description of the Drops themselves: some conjectures at the cause of the
+  </i>Phænomena<i>, indeavoured to be made probable by several Arguments
+  and Experiments. An Experiment of the expansion of Water by heat, and
+  shrinking by cold: the like Proprieties suppos'd in Glass drops, and what
+  effects proceed from them: the seven Propositions on which the
+  conjectures are grounded. Experiments to shew, that bodies expand by
+  heat. The manner of making </i>Thermometers<i>, and the Instrument for
+  </i>graduating<i> them. The manner of </i>graduating<i> them, and their
+  use: Other Experiments to prove the expansion of bodies by heat. Four
+  experimental Arguments to prove the expansion of Glass by heat: further
+  prov'd by the Experiment of boyling Alabaster; which is explicated. An
+  explication of the contracting of heated Glass upon cooling. An
+  explication how the parts of the Glass become bent by sudden cold, and
+  how kept from extricating themselves by the contignation of the Glass
+  drop; which is further explicated by another Experiment made with a
+  hollow Glass ball: the reason of the flying asunder of the parts further
+  explicated: that 'tis probable these bodies may have many flaws, though
+  not visible, and why: how a gradual heating and cooling does put the
+  parts of Glass, and other hardned bodies, into a looser texture.</i></p>
+
+  <p>Observ. <a href="#obsVIII">8</a>. Of Fiery Sparks.</p>
+
+  <p><i>The occasion and manner of making this Experiment: divers
+  Observations set down in order to the finding out the reasons: some
+  conjectures concerning it, which are endeavoured to be explicated and
+  confirm'd by several Experiments and Reasons: the </i>Hypothesis<i> a
+  little further explicated. Some Observations about the Globular Figure:
+  and an Experiment of reducing the filings of Tin or Lead to exactly round
+  Globules.</i></p>
+
+  <p>Observ. <a href="#obsIX">9</a>. Of Fantastical Colours.</p>
+
+  <p><i>The texture of </i>Muscovy<i> Glass; its Figures: what other Bodies
+  are like it: that it exhibits several colours, and how: several
+  Observations and Experiments about those colours: the reason why on this
+  occasion the nature of colours is inquir'd into. A conjecture at the
+  reason of these colours explicated by several Experiments and Reasons:
+  First, by continual cleaving the Body till it become colour'd. Secondly,
+  by producing all kinds of colours with two flat Plates of Glass. Thirdly,
+  by blowing Glass so thin in the Lamp, till it produce the same effect.
+  Fourthly, by doing the same with Bubbles of divers other transparent
+  Bodies: the reasons of the colours on nealed Steel, where by the way the
+  causes of the hardning and tempering of Steel,
+  endeavour'd to be shewn and explicated by several Reasons and
+  Experiments: the reason of the colours on Lead, Brass, Copper, Silver,
+  </i>&amp;c.<i> other Instances of such colour'd bodies in animal
+  substances: several other distinguishing Observations. </i>Des Cartes
+  Hypothesis<i> of Colours examin'd. An </i>Hypothesis<i> for the
+  explication of light by motion, indeavoured to be explicated and
+  determined by several Reasons and Experiments: three distinguishing
+  Properties of the motion of light. The distinguishing Properties of a
+  trasparent </i>Medium<i> [that there seems to be no Experiment that
+  proves the Instantaneous motion of light] the manner of the propagation
+  of light through them. Of the </i>homogeniety<i> and </i>heterogeniety<i>
+  of transparent </i>Mediums<i>, and what effects they cause on the Rayes
+  of light, explicated by a Figure: an Examination of the refraction of the
+  Rays by a plain Surface, which causes Colours. An Examination of the like
+  effects produced by a spherical Surface: the use that may be made of
+  these Experiments, for the examination of several </i>Hypotheses<i> of
+  Colours. </i>Des Cartes Hypothesis<i> examin'd. Some Difficulties taken
+  notice of in it. What seems most likely to be the cause of colour: that
+  propriety is indeavoured to be shewn in a Glass ball: that the reflection
+  is not necessary to produce Colours nor a double refraction: the
+  </i>Hypothesis<i> further examined, both in the </i>pellucid Medium<i>
+  and in the Eye. The definitions of Colours; and a further explication and
+  examination of the Proprieties of </i>laminated<i> Bodies; by what means
+  they conduce to the production of Colours.</i></p>
+
+  <p>Observ. <a href="#obsX">10</a>. Of Metalline Colours.</p>
+
+  <p><i>That all Colours seem to be caus'd by refraction. An
+  </i>Hypothesis<i> consonant hereunto, explicated by Figures. How several
+  Experiments, of the sudden changing of Colours by Chymical Liquors may be
+  hereby explicated: how many wayes such Chymical Liquors may alter the
+  colours of Bodies. Objections made against this </i>Hypothesis<i> of two
+  colours only, indeavoured to be answer'd, by several Reasons and
+  Experiments. The reason why some Colours are capable of being diluted,
+  others not: what those are: that probably the particles of most metalline
+  Colours are transparent; for this several Arguments and Observations are
+  recited: how Colours become incapable of diluting, explicated by a
+  Similitude. An Instrument, by which one and the same coloured Liquor at
+  once exhibited all the degrees of colours between the palest yellow and
+  deepest red: as likewise another that exhibited all varieties of blues:
+  several Experiments try'd with these Boxes. An Objection drawn from the
+  nature of Painters colours answered: that diluting and whitening a colour
+  are different operations; as are deepening and blackening: why some may
+  be diluted by grinding, and some other by being tempered with Oyl:
+  several Experiments for the explicating of some former Assertions: why
+  Painters are forced to make use of many colours: what those colours are:
+  and how mixt. The conclusion, that most coloured Bodies seem to consist
+  of transparent particles: that all colours dissoluble in Liquors are
+  capable of diluting: some of mixing, what a strange variety may thereby
+  be produc'd.</i></p>
+
+  <p>Observ. <a href="#obsXI">11</a>. Of the Figures of Sand.</p>
+
+  <p><i>Of the substances and shapes of common
+  and other Sands: a description of a very small Shell.</i></p>
+
+  <p>Observ. <a href="#obsXII">12</a>. Of Gravel in Urine.</p>
+
+  <p><i>A description of such Gravel, and some tryals made with it, and
+  conjectures at its cause.</i></p>
+
+  <p>Obser. <a href="#obsXIII">13</a>. Of Diamonds in Flints.</p>
+
+  <p><i>A description and examination of some of them, explicated further
+  by Cornish Diamonds: several Observations about reflection and
+  refraction: and some deductions therefrom; as an explication of
+  whiteness; that the Air has a stronger reflection then Water. How several
+  Bodies may be made transparent: an explication of the </i>Phænomena<i> of
+  </i>Oculus Mundi<i>. Of the regular Geometrical Figures of several
+  Bodies: an hypothetical explication mentioned: the method of prosecuting
+  this inquiry.</i></p>
+
+  <p>Observ. <a href="#obsXIV">14</a>. Of frozen Figure.</p>
+
+  <p><i>The Figures of hoar Frost, and the Vortices on windows: several
+  Observations on the branched Figures of Urine: the Figures of </i>Regulus
+  Martis stellatus<i>, and of Fern. Of the Figures of Snow. Of frozen
+  water.</i></p>
+
+  <p>Observ. <a href="#obsXV">15</a>. Of Kettering Stone.</p>
+
+  <p><i>A description of the Figure of the Particles, and of the Pores, and
+  of the Contexture. Several Observations and Considerations thereupon:
+  some Conjectures about the </i>medium<i> and propagation of light, and
+  the constitution of fluid and transparent Bodies. Several Experiments to
+  prove the porousness of Marble, and some other Stones. An account of some
+  Experiments to this purpose made on an </i>Oculus Mundi<i>: some other
+  Considerations and Experiments about the porousness of Bodies: some other
+  Considerations about the propagation of light and refraction.</i></p>
+
+  <p>Observ. <a href="#obsXVI">16</a>. Of Charcoal.</p>
+
+  <p><i>Of two sort of Pores to be found in all Woods and Vegetables; the
+  shape of them; the number, thickness, manner and use of these Pores. An
+  explication of the </i>Phænomena<i> of Coals. The manner of charring
+  Wood, or any other body. What part of Wood is combustible. An
+  </i>Hypothesis<i> of fire explicated in twelve particulars, wherein the
+  Action of the Air, as a </i>Menstruum<i> in the dissolution of all
+  sulphureous bodies, is very particularly explicated, and some other
+  Considerations about the Air proposed: the examination of a piece of
+  </i>Lignum fossile<i> sent from </i>Rome<i>, and some Conclusions thence
+  deduc'd.</i></p>
+
+  <p>Observ. <a href="#obsXVII">17</a>. Of Wood, and other Bodies,
+  petrified.</p>
+
+  <p><i>Several Observations of divers kinds of these substances. A more
+  particular examination and explication of one very notable piece of
+  petrified Wood; and some Conjectures about the cause of those
+  productions: several Observations made on other petrified Bodies, as
+  shells, </i>&amp;c.<i> And some probable Conclusions thence deduc'd,
+  about the original cause of those Bodies.</i></p>
+
+  <p>Observ. <a href="#obsXVIII">18</a>. Of the Pores of Cork, and other
+  Bodies.</p>
+
+  <p><i>Several Observations and Considerations about the nature of Cork:
+  the number of Pores in a cubical Inch, and
+  several considerations about Pores. Several Experiments and Observations
+  about the nature of Cork: the Texture and Pores of the Pith of an Elder,
+  and several other Trees: of the Stales of Burdocks, Teasels, Daisies,
+  Carret, Fennel, Ferne, Reeds, </i>&amp;c.<i> of the frothy texture of the
+  Pith of a Feather: some Conjectures about the probability of values in
+  these Pores. Argued also from the </i>Phænomena<i> of sensible and humble
+  Plant: some Observations on which are inserted.</i></p>
+
+  <p>Observ. <a href="#obsXIX">19</a>. Of a Vegetable growing on blighted
+  Leaves.</p>
+
+  <p><i>Several Observations and Examinations made of them: several
+  Considerations about spontaneous generation arising from the putrefaction
+  of Bodies.</i></p>
+
+  <p>Observ. <a href="#obsXX">20</a>. Of Blew Mould and Mushromes.</p>
+
+  <p><i>The description of several kinds of Moulds. The method of
+  proceeding in natural Inquiries. Several Considerations about the nature
+  of Mould and Mushromes. 1. That they may be produc'd without seed. 2.
+  That they seem to have none. 3. That Salts, </i>&amp;c.<i> are shap'd
+  into as curious figures without a seed. 4. Of a kind of Mushrome growing
+  in a Candle: A more particular explication of this last sort of
+  Mushromes. 5. Of the figure and manner of the production of petrified
+  Iceicles: several deductions from these Considerations, about the nature
+  of the vegetation of Mould and Mushromes.</i></p>
+
+  <p>Observ. <a href="#obsXXI">21</a>. Of Moss.</p>
+
+  <p><i>The description of several sorts of Mosses; upon this occasion
+  several Conjectures, about the manner of the production of these kinds of
+  Bodies, are hinted, and some of them explicated by a Similitude taken
+  from a piece of Clock-work, The vast difference of the bigness of
+  vegetable Bodies; and the probability that the least may comprehend as
+  curious contrivances as the greatest. Of multitudes of other Moulds,
+  Mosses, and Mushromes, and other vegetating Principles, in Water, Wood,
+  </i>&amp;c.</p>
+
+  <p>Observ. <a href="#obsXXII">22</a>. Of Sponges, and other fibrous
+  Bodies.</p>
+
+  <p><i>Several Observations and Conjectures about the making of these
+  Bodies, and several Histories out of Authors. Scarce any other Body hath
+  such a texture; the fibrous texture of Leather, Spunk, </i>&amp;c.<i>
+  (which are there describ'd) come nearest to it That upon tryal with a
+  piece of Spunge and Oyl the necessity of respiration could not be
+  alter'd.</i></p>
+
+  <p>Observ. <a href="#obsXXIII">23</a>. Of the Form of Seaweed.</p>
+
+  <p><i>From the curiously shap'd Surface of this Sea-weed, and some
+  others, is conjectured the possibility of Multitudes of the like.</i></p>
+
+  <p>Observ. <a href="#obsXXIV">24</a>. Of the Surfaces of some Leaves.</p>
+
+  <p><i>The description, 1. Of the bald Surfaces of Leaves. 2. Of the downy
+  Surfaces of several others. 3. Of the gummous exsudation, or small
+  transparent Pearls, discovered with a </i>Microscope<i> in several
+  others. An Instance of all which is afforded in a Rosemary Leaf.</i></p>
+
+  <p>Observ. <a href="#obsXXV">25</a>. Of the stinging Points of a
+  Nettle.</p>
+
+  <p><i>A description of the Needles and several other contrivances in the
+  leaf of a Nettle: how the stinging pain is created: upon this several
+  considerations about poysoning Darts are set down. An Experiment of
+  killing Effs, and Fishes with Salt. Some conjectures at the efficacy of
+  Baths; the use that may be made of injecting into the Veins. A very
+  remarkable History out of </i>Bellonius<i>; and some Considerations about
+  staining and dying of Bodies.</i></p>
+
+  <p>Observ. <a href="#obsXXVI">26</a>. Of Cowage.</p>
+
+  <p><i>The definition of it out of </i>Parkinson<i>: an Experiment made of
+  it: a description, and some conjectures at the cause of the
+  </i>Phænomena<i>.</i></p>
+
+  <p>Observ. <a href="#obsXXVII">27</a>. Of the Beard of a wild Oat.</p>
+
+  <p><i>The description of its shape and properties: the manner of making a
+  </i>Hygroscope<i> with it; and a Conjecture at the causes of these
+  motions, and of the motions of the Muscles.</i></p>
+
+  <p>Observ. <a href="#obsXXVIII">28</a>. Of the Seeds of <i>Venice</i>
+  Looking-glass.</p>
+
+  <p><i>The description of them.</i></p>
+
+  <p>Obser. <a href="#obsXXIX">29</a>. Of the Seeds of Time.</p>
+
+  <p><i>A description of them. A digression about Natures method.</i></p>
+
+  <p>Observ. <a href="#obsXXX">30</a>. Of Poppy Seeds.</p>
+
+  <p><i>The description and use of them.</i></p>
+
+  <p>Observ. <a href="#obsXXXI">31</a>. Of Purslane Seeds.</p>
+
+  <p><i>A description of these and many other Seeds.</i></p>
+
+  <p>Observ. <a href="#obsXXXII">32</a>. Of Hair.</p>
+
+  <p><i>The description of several sorts of Hair; their Figures and
+  Textures: the reason of their colours, A description of the texture of
+  the skin, and of Spunk and Sponges: by what passages and pores of the
+  skin transpiration seems to be made. Experiments to prove the porousness
+  of the skin of Vegetables.</i></p>
+
+  <p>Observ. <a href="#obsXXXIII">33</a>. Of the Scales of a Soale.</p>
+
+  <p><i>A description of their beauteous form.</i></p>
+
+  <p>Observ. <a href="#obsXXXIV">34</a>. Of the Sting of a Bee.</p>
+
+  <p><i>A description of its shape, mechanisme, and use.</i></p>
+
+  <p>Observ. <a href="#obsXXXV">35</a>. Of Feathers.</p>
+
+  <p><i>A description of the shape and curious contexture of Feathers: and
+  some conjectures thereupon.</i></p>
+
+  <p>Obser. <a href="#obsXXXVI">36</a>. Of Peacocks Feathers.</p>
+
+  <p><i>A description of their curious form and proprieties; with a
+  conjecture at the cause of their variable colours.</i></p>
+
+  <p>Obser. <a href="#obsXXXVII">37</a>. Of the Feet of Flyes, and other
+  Insects.</p>
+
+  <p><i>A description of their figure, parts, and use; and some
+  considerations thereupon.</i></p>
+
+  <p>Obser. <a href="#obsXXXVIII">38</a>. Of the Wings of Flyes.</p>
+
+  <p><i>After what manner and how swiftly the wings of Insects move. A
+  description of the Pendulums under the wings, and their motion; the shape
+  and structure of the parts of the wing.</i></p>
+
+  <p>Obser. <a href="#obsXXXIX">39</a>. Of the Head of a Fly.</p>
+
+  <p><i>1. All the face of a Drone-fly is nothing almost but eyes. 2. Those
+  are of two magnitudes. 3. They are Hemispheres, and very reflective and
+  smooth. 4. Some directed towards every quarter. 5. How the fly cleanses
+  them. 6. Their number. 7. Their order: divers particulars observ'd in the
+  dissecting a head. That these are very probably the eyes of the Creature;
+  argued from several Observations and Experiments, that Crabs, Lobsters,
+  Shrimps, seem to be water Insects, and to be framed much like Air
+  Insects. Several Considerations about their manner of vision.</i></p>
+
+  <p>Obser. <a href="#obsXL">40</a>. Of the Teeth of a Snail.</p>
+
+  <p><i>A brief description of it.</i></p>
+
+  <p>Observ. <a href="#obsXLI">41</a>. Of the Eggs of Silkworms.</p>
+
+  <p><i>Several Observables about the Eggs of Insects.</i></p>
+
+  <p>Observ. <a href="#obsXLII">42</a>. Of a blue Fly.</p>
+
+  <p><i>A description of its outward and inward parts. Its hardiness to
+  indure freezing, and sleeping in Spirit of wine.</i></p>
+
+  <p>Observ. <a href="#obsXLIII">43</a>. Of a water Insect.</p>
+
+  <p><i>A description of its shape, transparency, motion, both internal and
+  progressive, and transformation. A History somewhat </i>Analogus<i> cited
+  out of </i>Piso<i>. Several Observations about the various wayes of the
+  generations of Insects: by what means they act so seemingly wisely and
+  prudently. Several Quæries propounded. Postscript, containing a relation
+  of another very odd way of the generation of Insects. An Observation
+  about the fertility of the Earth of our Climate in producing Insects, and
+  of divers other wayes of their generation.</i></p>
+
+  <p>Observ. <a href="#obsXLIV">44</a>. Of the tufted Gnat.</p>
+
+  <p><i>Several Observables about Insects, and a more particular
+  description the parts of this Gnat.</i></p>
+
+  <p>Ob. <a href="#obsXLV">45</a>. Of the great belly'd Gnat.</p>
+
+  <p><i>A short description of it.</i></p>
+
+  <p>Obser. <a href="#obsXLVI">46</a>. Of a white Moth.</p>
+
+  <p><i>A description of the feathers and wings of this, and several other
+  Insects. Divers Considerations about the wings, and the flying of Insects
+  and Birds.</i></p>
+
+  <p>Obs. <a href="#obsXLVII">47</a>. Of the Shepherd Spider.</p>
+
+  <p><i>A description of its Eyes: and the sockets of its long legs: and a
+  Conjecture of the mechanical reason of its fabrick; together with a
+  supposition, that 'tis not unlikely, but Spiders may have the make of
+  their inward parts exactly like a Crab, which may be call'd a water
+  Spider.</i></p>
+
+  <p>Obser. <a href="#obsXLVIII">48</a>. Of the hunting Spider.</p>
+
+  <p><i>A short description of it; to which is annext an excellent History
+  of it, made by Mr. </i>Evelyn<i>. Some further   Observations on other Spiders, and their Webs, together with an
+  examination of a white Substance flying up and down in the Air after a
+  Fog.</i></p>
+
+  <p>Obser. <a href="#obsXLIX">49</a>. Of an Ant.</p>
+
+  <p><i>That all small Bodies, both Vegetable and Animal, do quickly dry
+  and wither. The best remedy I found to hinder it, and to make the Animal
+  lye still to be observ'd. Several particulars related of the actions of
+  this Creature and a short description of its parts.</i></p>
+
+  <p>Obs. <a href="#obsL">50</a>. Of the wandring Mite.</p>
+
+  <p><i>A description of this Creature, and of another very small one,
+  which usually bore it company. A Conjecture at the original of
+  Mites.</i></p>
+
+  <p>Observ. <a href="#obsLI">51</a>. Of a Crab-like Insect.</p>
+
+  <p><i>A brief description of it.</i></p>
+
+  <p>Observ. <a href="#obsLII">52</a>. Of a Book-worm.</p>
+
+  <p><i>A description of it; where by the way is inserted a digression,
+  experimentally explicating the </i>Phænomena<i> of Pearl. A consideration
+  of its digestive faculty.</i></p>
+
+  <p>Observ. <a href="#obsLIII">53</a>. Of a Flea.</p>
+
+  <p><i>A short description of it.</i></p>
+
+  <p>Observ. <a href="#obsLIV">54</a>. Of a Louse.</p>
+
+  <p><i>A description of its parts, and some notable circumstances.</i></p>
+
+  <p>Observ. <a href="#obsLV">55</a>. Of Mites.</p>
+
+  <p><i>The exceeding smalness of some Mites, and their Eggs. A description
+  of the Mites of Cheese: and an intimation of the variety of forms in
+  other Mites, with a Conjecture at the reason.</i></p>
+
+  <p>Ob. <a href="#obsLVI">56</a>. Of small Vine-Mites.</p>
+
+  <p><i>A description of them; a ghess at their original; their exceeding
+  smalness compar'd with that of a Wood-louse, from which they may be
+  suppos'd to come.</i></p>
+
+  <p>Observ. <a href="#obsLVII">57</a>. Of Vinegar-worms.</p>
+
+  <p><i>A description of them, with some considerations on their
+  motions.</i></p>
+
+  <p>Obs. <a href="#obsLVIII">58</a>. Of the Inflexion of the Rays of Light
+  in the Air.</p>
+
+  <p><i>A short rehearsal of several </i>Phænomena<i>. An attempt to
+  explicate them: the supposition founded on two Propositions, both which
+  are indeavoured to be made out by several Experiments, What density and
+  rarity is in respect of refraction: the refraction of Spirit of Wine
+  compared with that of common Water: the refraction of Ice. An Experiment
+  of making an Undulation of the Rays by the mixing of Liquors of differing
+  density. The explication of </i>inflection<i>, mechanically and
+  hypothetically: what Bodies have such an inflection. Several Experiments
+  to shew that the Air has this propriety; that it proceeds from the
+  differing density of the Air: that the upper and under part of the Air
+  are of differing density: some Experiments to prove this. A Table of the
+  strength of the spring of the Air, answering to each degree of extension;
+  when first made, and when repeated. Another Experiment of compressing the
+  Air. A Table of the strength of the Air, answering to each compression
+  and expansion; from which the height of the
+  Air may be suppos'd indefinite; to what degree the Air is rarifi'd at any
+  distance above the Surface of the Earth: how, from this, Inflection is
+  inferr'd; and several </i>Phænomena<i> explain'd. That the Air near the
+  Earth is compos'd of parts of differing density; made probable by several
+  Experiments and Observations; how this propriety produces the effects of
+  the waving and dancing of Bodies; and of the twinkling of the Stars.
+  Several </i>Phænomena<i> explicated. Some Quæries added.</i></p>
+
+  <p>1. <i>Whether this Principle may not be made use of, for perfecting
+  Optick Glasses? What might be hoped from it if it were to be
+  done?</i></p>
+
+  <p>2. <i>Whether from this Principle the apparition of some new Stars may
+  not be explicated?</i></p>
+
+  <p>3. <i>Whether the height of the Air may be defin'd by it?</i></p>
+
+  <p>4. <i>Whether there may not sometimes be so great a disparity of
+  density between the upper and under parts of the Air, as to make a
+  reflecting Surface?</i></p>
+
+  <p>5. <i>Whether, if so, this will not explicate the </i>Phænomena<i> of
+  the Clouds. An Experiment to this purpose?</i></p>
+
+  <p>7. <i>Whether the Rayes from the top of Mountains are not bended into
+  Curve-lines by inflection? An Argument for it, taken from an Experiment
+  made on St. </i>Paul<i>'s Steeple.</i></p>
+
+  <p>8. <i>Whether the distance of the Planets will not be more difficult
+  to be found? What wayes are most likely to rectifie the distance of the
+  Moon: the way of fitting </i>Telescopes<i> for such Observations. How to
+  make the Observations, and how from them to find the true distance of the
+  Moon at any time. How the distance of the Sun may be found by two
+  Observators. The way by the Dicotomy of the Moon uncertain. That the
+  distance of the Moon may be less then it has been hitherto suppos'd.
+  </i>Kepler<i>'s Supposition not so probable: the explication of the
+  </i>Phænomena<i> by another </i>Hypothesis<i>.</i></p>
+
+  <p>Observ. <a href="#obsLIX">59</a>. Of the fixt Stars.</p>
+
+  <p><i>Of the multitudes of Stars discoverable by the </i>Telescope<i>,
+  and the variety of their magnitudes: 78. Stars distinguisht in the
+  </i>Pleiades<i>: that there are degrees of bigness even in the Stars
+  accounted of the same magnitude: the longer the Glasses are, and the
+  bigger apertures they will indure, the more fit they are for these
+  discoveries: that 'tis probable, longer Glasses would yet make greater
+  discoveries. 5. Stars discover'd in the </i>Galaxie<i> of </i>Orion<i>'s
+  Sword.</i></p>
+
+  <p>Observ. <a href="#obsLX">60</a>. Of the Moon.</p>
+
+  <p><i>A description of a Vale in the Moon; what call'd by </i>Hevelius<i>
+  and </i>Ricciolus<i>, and how describ'd by them: with what substances the
+  hills of the Moon may be cover'd. A description of the pits of the Moon,
+  and a conjecture at their cause: two Experiments that make it probable,
+  that of the surface of boyl'd Alabaster dust seeming the most likely to
+  be resembled by eruptions of vapours out of the body of the Moon: that
+  Earthquakes seem to be generated much the same way, and their effects
+  seem very similar. An Argument that there may be such variations in the
+  Moon, because greater have been observ'd in the Sun: because substance of
+  the Moon and Earth seem much alike: and because 'tis probable the Moon
+  has a gravitating principle: this is argued from several particulars. The
+  reason why several pits are one within another. The use that may be made
+  of this Instance of a gravity in the Moon.</i></p>
+
+  <br clear="all" />
+<hr class="full" />
+
+<h2>The <i>Schemes</i>.</h2>
+<table border="1">
+  <tr>
+    <td class="tc"><a href="images/scheme-01.png" target="_blank">
+      <img class="nobo" src="images/scheme-01t.png" alt="Scheme 1" /></a><br /><i>Schem.</i> 1.<br />
+      <a href="#prefref">Prefix.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-02.png" target="_blank">
+      <img class="nobo" src="images/scheme-02t.png" alt="Scheme 2" /></a><br /><i>Schem.</i> 2.<br />
+      Obs. <a href="#obsI">1.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-03.png" target="_blank">
+      <img class="nobo" src="images/scheme-03t.png" alt="Scheme 3" /></a><br /><i>Schem.</i> 3.<br />
+      Obs. <a href="#obsIV">4,</a> <a href="#obsV">5.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-04.png" target="_blank">
+      <img class="nobo" src="images/scheme-04t.png" alt="Scheme 4" /></a><br /><i>Schem.</i> 4.<br />
+      Obs. <a href="#obsVI">6,</a> <a href="#obsVII">7.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-05.png" target="_blank">
+      <img class="nobo" src="images/scheme-05t.png" alt="Scheme 5" /></a><br /><i>Schem.</i> 5.<br />
+      Obs. <a href="#obsVIII">8,</a> <a href="#obsXI">11,</a> <a href="#obsXXXII">32.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-06.png" target="_blank">
+      <img class="nobo" src="images/scheme-06t.png" alt="Scheme 6" /></a><br /><i>Schem.</i> 6.<br />
+      Obs. <a href="#obsIX">9,</a> <a href="#obsX">10.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-07.png" target="_blank">
+      <img class="nobo" src="images/scheme-07t.png" alt="Scheme 7" /></a><br /><i>Schem.</i> 7.<br />
+      Obs. <a href="#obsXII">12,</a> <a href="#obsXIII">13.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-08.png" target="_blank">
+      <img class="nobo" src="images/scheme-08t.png" alt="Scheme 8" /></a><br /><i>Schem.</i> 8.<br />
+      Obs. <a href="#obsXIV">14.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-09.png" target="_blank">
+      <img class="nobo" src="images/scheme-09t.png" alt="Scheme 9" /></a><br /><i>Schem.</i> 9.<br />
+      Obs. <a href="#obsXV">15,</a> <a href="#obsXXII">22,</a> <a href="#obsXXIII">23.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-10.png" target="_blank">
+      <img class="nobo" src="images/scheme-10t.png" alt="Scheme 10" /></a><br /><i>Schem.</i> 10.<br />
+      Obs. <a href="#obsXVII">17.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-11.png" target="_blank">
+      <img class="nobo" src="images/scheme-11t.png" alt="Scheme 11" /></a><br /><i>Schem.</i> 11.<br />
+      Obs. <a href="#obsXVIII">18.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-12.png" target="_blank">
+      <img class="nobo" src="images/scheme-12t.png" alt="Scheme 12" /></a><br /><i>Schem.</i> 12.<br />
+      Obs. <a href="#obsXIX">19,</a> <a href="#obsXX">20.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-13.png" target="_blank">
+      <img class="nobo" src="images/scheme-13t.png" alt="Scheme 13" /></a><br /><i>Schem.</i> 13.<br />
+      Obs. <a href="#obsXXI">21.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-14.png" target="_blank">
+      <img class="nobo" src="images/scheme-14t.png" alt="Scheme 14" /></a><br /><i>Schem.</i> 14.<br />
+      Obs. <a href="#obsXXIII">23,</a> <a href="#obsXXIV">24.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-15.png" target="_blank">
+      <img class="nobo" src="images/scheme-15t.png" alt="Scheme 15" /></a><br /><i>Schem.</i> 15.<br />
+      Obs. <a href="#obsXXV">25,</a> <a href="#obsXXVII">27.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-16.png" target="_blank">
+      <img class="nobo" src="images/scheme-16t.png" alt="Scheme 16" /></a><br /><i>Schem.</i> 16.<br />
+      Obs. <a href="#obsXXVI">26,</a> <a href="#obsXXXIV">34.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-17.png" target="_blank">
+      <img class="nobo" src="images/scheme-17t.png" alt="Scheme 17" /></a><br /><i>Schem.</i> 17.<br />
+      Obs. <a href="#obsXXVIII">28.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-18.png" target="_blank">
+      <img class="nobo" src="images/scheme-18t.png" alt="Scheme 18" /></a><br /><i>Schem.</i> 18.<br />
+      Obs. <a href="#obsXXIX">29.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-19.png" target="_blank">
+      <img class="nobo" src="images/scheme-19t.png" alt="Scheme 19" /></a><br /><i>Schem.</i> 19.<br />
+      Obs. <a href="#obsXXX">30.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-20.png" target="_blank">
+      <img class="nobo" src="images/scheme-20t.png" alt="Scheme 20" /></a><br /><i>Schem.</i> 20.<br />
+      Obs. <a href="#obsXXXI">31.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-21.png" target="_blank">
+      <img class="nobo" src="images/scheme-21t.png" alt="Scheme 21" /></a><br /><i>Schem.</i> 21.<br />
+      Obs. <a href="#obsXXXIII">33.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-22.png" target="_blank">
+      <img class="nobo" src="images/scheme-22t.png" alt="Scheme 22" /></a><br /><i>Schem.</i> 22.<br />
+      Obs. <a href="#obsXXXV">35,</a> <a href="#obsXXXVI">36.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-23.png" target="_blank">
+      <img class="nobo" src="images/scheme-23t.png" alt="Scheme 23" /></a><br /><i>Schem.</i> 23.<br />
+      Obs. <a href="#obsXXXVII">37,</a> <a href="#obsXXXVIII">38,</a> <a href="#obsXXXIX">39.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-24.png" target="_blank">
+      <img class="nobo" src="images/scheme-24t.png" alt="Scheme 24" /></a><br /><i>Schem.</i> 24.<br />
+      Obs. <a href="#obsXXXIX">39,</a> <a href="#obsXLII">42.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-25.png" target="_blank">
+      <img class="nobo" src="images/scheme-25t.png" alt="Scheme 25" /></a><br /><i>Schem.</i> 25.<br />
+      Obs. <a href="#obsXL">40,</a> <a href="#obsXLI">41,</a> <a href="#obsLVII">57.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-26.png" target="_blank">
+      <img class="nobo" src="images/scheme-26t.png" alt="Scheme 26" /></a><br /><i>Schem.</i> 26.<br />
+      Obs. <a href="#obsXXXVIII">38,</a> <a href="#obsXLII">42.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-27.png" target="_blank">
+      <img class="nobo" src="images/scheme-27t.png" alt="Scheme 27" /></a><br /><i>Schem.</i> 27.<br />
+      Obs. <a href="#obsXLIII">43.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-28.png" target="_blank">
+      <img class="nobo" src="images/scheme-28t.png" alt="Scheme 28" /></a><br /><i>Schem.</i> 28.<br />
+      Obs. <a href="#obsXLIV">44.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-29.png" target="_blank">
+      <img class="nobo" src="images/scheme-29t.png" alt="Scheme 29" /></a><br /><i>Schem.</i> 29.<br />
+      Obs. <a href="#obsXLV">45.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-30.png" target="_blank">
+      <img class="nobo" src="images/scheme-30t.png" alt="Scheme 30" /></a><br /><i>Schem.</i> 30.<br />
+      Obs. <a href="#obsXLVI">46.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-31.png" target="_blank">
+      <img class="nobo" src="images/scheme-31t.png" alt="Scheme 31" /></a><br /><i>Schem.</i> 31.<br />
+      Obs. <a href="#obsXLVII">47.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-32.png" target="_blank">
+      <img class="nobo" src="images/scheme-32t.png" alt="Scheme 32" /></a><br /><i>Schem.</i> 32.<br />
+      Obs. <a href="#obsXLIX">49.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-33.png" target="_blank">
+      <img class="nobo" src="images/scheme-33t.png" alt="Scheme 33" /></a><br /><i>Schem.</i> 33.<br />
+      Obs. <a href="#obsL">50,</a> <a href="#obsLI">51,</a> <a href="#obsLII">52.</a>
+    </td>
+    <td class="tc" colspan="2"><a href="images/scheme-34.png" target="_blank">
+      <img class="nobo" src="images/scheme-34t.png" alt="Scheme 34" /></a><br /><i>Schem.</i> 34.<br />
+      Obs. <a href="#obsLIII">53.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-35.png" target="_blank">
+      <img class="nobo" src="images/scheme-35t.png" alt="Scheme 35" /></a><br /><i>Schem.</i> 35.<br />
+      Obs. <a href="#obsLIV">54.</a>
+    </td>
+  </tr>
+  <tr>
+    <td class="tc"><a href="images/scheme-36.png" target="_blank">
+      <img class="nobo" src="images/scheme-36t.png" alt="Scheme 36" /></a><br /><i>Schem.</i> 36.<br />
+      Obs. <a href="#obsLVI">56.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-37.png" target="_blank">
+      <img class="nobo" src="images/scheme-37t.png" alt="Scheme 37" /></a><br /><i>Schem.</i> 37.<br />
+      Obs. <a href="#obsLVIII">58.</a>
+    </td>
+    <td class="tc"><a href="images/scheme-38.png" target="_blank">
+      <img class="nobo" src="images/scheme-38t.png" alt="Scheme 38" /></a><br /><i>Schem.</i> 38.<br />
+      Obs. <a href="#obsLX">60.</a>
+    </td>
+    <td class="tc">&nbsp;
+    </td>
+  </tr>
+</table>
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