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diff --git a/old/12861.txt b/old/12861.txt new file mode 100644 index 0000000..da80f0c --- /dev/null +++ b/old/12861.txt @@ -0,0 +1,11981 @@ +The Project Gutenberg eBook, Theory of the Earth, Volume 1 (of 4), by +James Hutton + + +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: Theory of the Earth, Volume 1 (of 4) + +Author: James Hutton + +Release Date: July 9, 2004 [eBook #12861] + +Language: English + +Character set encoding: ISO-646-US (US-ASCII) + + +***START OF THE PROJECT GUTENBERG EBOOK THEORY OF THE EARTH, VOLUME 1 (OF +4)*** + + +E-text prepared by Robert Shimmin, Renald Levesque, and the Project +Gutenberg Online Distributed Proofreading Team + + + +THEORY OF THE EARTH, VOLUME I + +With Proofs and Illustrations, in Four Parts + +By + +JAMES HUTTON, M.D. & F.R.S.E. + +1795. + + + + + + + +CONTENTS. + + +PART I. + +THEORY OF THE EARTH; with the Examination of different Opinions on +that Subject. + + +CHAP. I. + +THEORY OF THE EARTH; or an Investigation of the Laws observable in the +Composition, Dissolution, and Restoration of Land upon the Globe. + +SECT. I.--Prospect of the Subject to be treated of. + +SECT. II.--An Investigation of the Natural Operations employed in +consolidating the Strata of the Globe. + +SECT. III.--Investigation of the Natural Operations employed in the +Production of Land above the Surface of the Sea. + +SECT. IV.--System of Decay and Renovation observed in the Earth. + + +CHAP. II. + +An Examination of Mr KIRWAN's Objections to the Igneous Origin of Stony +Substances. + + +CHAP. III. + +Of Physical Systems, and Geological Theories, in general. + + +CHAP. IV. + +The Supposition of Primitive Mountains refuted. + + +CHAP. V. + +Concerning that which may be termed the Primary Part of the Present +Earth. + + +CHAP. VI. + +The Theory of interchanging Sea and Land, illustrated by an +Investigation of the Primary and Secondary Strata 421. + +SECT. I.--A distinct view of the Primary and Secondary Strata. + +SECT. II.--The Theory confirmed from Observations made on purpose to +elucidate the Subject. + + +CHAP. VII. + +Opinions examined with regard to Petrifaction, or Mineral Concretion. + + +CHAP. VIII. + +The Nature of Mineral Coal, and the Formation of Bituminous Strata, +investigated. + +SECT. I.--Purpose of this Inquiry. + +SECT. II.--Natural History of Coal Strata, and Theory of this +Geological Operation. + +SECT. III.--The Mineralogical Operations of the Earth illustrated from +the Theory of Fossil Coal. + + + + +PART I. + +THEORY OF THE EARTH; + +WITH THE + +EXAMINATION + +OF + +DIFFERENT OPINIONS ON THAT SUBJECT. + + + + +IN EIGHT CHAPTERS. + + + +CHAPTER I. + +THEORY of the EARTH; or an Investigation of the Laws observable in the +Composition, Dissolution, and Restoration, of Land upon the Globe. + + +SECTION I. + +Prospect of the Subject to be treated of. + +When we trace the parts of which this terrestrial system is composed, +and when we view the general connection of those several parts, the +whole presents a machine of a peculiar construction by which it is +adapted to a certain end. We perceive a fabric, erected in wisdom, to +obtain a purpose worthy of the power that is apparent in the production +of it. + +We know little of the earth's internal parts, or of the materials which +compose it at any considerable depth below the surface. But upon the +surface of this globe, the more inert matter is replenished with plants, +and with animal and intellectual beings. + +Where so many living creatures are to ply their respective powers, in +pursuing the end for which they were intended, we are not to look for +nature in a quiescent state; matter itself must be in motion, and the +scenes of life a continued or repeated series of agitations and events. + +This globe of the earth is a habitable world; and on its fitness for +this purpose, our sense of wisdom in its formation must depend. To judge +of this point, we must keep in view, not only the end, but the means +also by which that end is obtained. These are, the form of the whole, +the materials of which it is composed, and the several powers which +concur, counteract, or balance one another, in procuring the general +result. + +The form and constitution of the mass are not more evidently calculated +for the purpose of this earth as a habitable world, than are the various +substances of which that complicated body is composed. Soft and hard +parts variously combine to form a medium consistence, adapted to the use +of plants and animals; wet and dry are properly mixed for nutrition, +or the support of those growing bodies; and hot and cold produce a +temperature or climate no less required than a soil: Insomuch, that +there is not any particular, respecting either the qualities of the +materials, or the construction of the machine, more obvious to +our perception, than are the presence and efficacy of design and +intelligence in the power that conducts the work. + +In taking this view of things, where ends and means are made the object +of attention, we may hope to find a principle upon which the comparative +importance of parts in the system of nature may be estimated, and also +a rule for selecting the object of our inquiries. Under this direction, +science may find a fit subject of investigation in every particular, +whether of _form_, _quality_, or _active power_, that presents itself in +this system of motion and of life; and which, without a proper +attention to this character of the system, might appear anomalous and +incomprehensible. + +It is not only by seeing those general operations of the globe which +depend upon its peculiar construction as a machine, but also by +perceiving how far the particulars, in the construction of that machine, +depend upon the general operations of the globe, that we are enabled to +understand the constitution of this earth as a thing formed by design. +We shall thus also be led to acknowledge an order, not unworthy of +Divine wisdom, in a subject which, in another view, has appeared as the +work of chance, or as absolute disorder and confusion. + +To acquire a general or comprehensive view of this mechanism of the +globe, by which it is adapted to the purpose of being a habitable world, +it is necessary to distinguish three different bodies which compose the +whole. These are, a solid body of earth, an aqueous body of sea, and an +elastic fluid of air. + +It is the proper shape and disposition of these three bodies that form +this globe into a habitable world; and it is the manner in which these +constituent bodies are adjusted to each other, and the laws of action +by which they are maintained in their proper qualities and respective +departments, that form the Theory of the machine which we are now to +examine. + +Let us begin with some general sketch of the particulars now mentioned. + +_1st_, There is a central body in the globe. This body supports those +parts which come to be more immediately exposed to our view, or which +may be examined by our sense and observation. This first part is +commonly supposed to be solid and inert; but such a conclusion is only +mere conjecture; and we shall afterwards find occasion, perhaps, to form +another judgment in relation to this subject, after we have examined +strictly, upon scientific principles, what appears upon the surface, and +have formed conclusions concerning that which must have been transacted +in some more central part. + +_2dly_, We find a fluid body of water. This, by gravitation, is reduced +to a spherical form, and by the centrifugal force of the earth's +rotation, is become oblate. The purpose of this fluid body is essential +in the constitution of the world; for, besides affording the means of +life and motion to a multifarious race of animals, it is the source of +growth and circulation to the organized bodies of this earth, in being +the receptacle of the rivers, and the fountain of our vapours. + +_3dly_, We have an irregular body of land raised above the level of the +ocean. This, no doubt, is the smallest portion of the globe; but it is +the part to us by far most interesting. It is upon the surface of this +part that plants are made to grow; consequently, it is by virtue of +this land that animal life, as well as vegetation, is sustained in this +world. + +_Lastly_, We have a surrounding body of atmosphere, which completes the +globe. This vital fluid is no less necessary, in the constitution of the +world, than are the other parts; for there is hardly an operation upon +the surface of the earth, that is not conducted or promoted by its +means. It is a necessary condition for the sustenance of fire; it is the +breath of life to animals; it is at least an instrument in vegetation; +and, while it contributes to give fertility and health to things that +grow, it is employed in preventing noxious effects from such as go into +corruption. In short, it is the proper means of circulation for the +matter of this world, by raising up the water of the ocean, and pouring +it forth upon the surface of the earth. + +Such is the mechanism of the globe: Let us now mention some of those +powers by which motion is produced, and activity procured to the mere +machine. + +First, There is the progressive force, or moving power, by which this +planetary body, if solely actuated, would depart continually from the +path which it now pursues, and thus be for ever removed from its end, +whether as a planetary body, or as a globe sustaining plants and +animals, which may be termed a living world. + +But this moving body is also actuated by gravitation, which inclines +it directly to the central body of the sun. Thus it is made to revolve +about that luminary, and to preserve its path. + +It is also upon the same principles, that each particular part upon the +surface of this globe, is alternately exposed to the influence of light +and darkness, in the diurnal rotation of the earth, as well as in its +annual revolution. In this manner are produced the vicissitudes of night +and day, so variable in the different latitudes from the equator to the +pole, and so beautifully calculated to equalise the benefits of light, +so variously distributed in the different regions of the globe. + +Gravitation, and the _vis infita_ of matter, thus form the first two +powers distinguishable in the operations of our system, and wisely +adapted to the purpose for which they are employed. + +We next observe the influence of light and heat, of cold and +condensation. It is by means of these two powers that the various +operations of this living world are more immediately transacted; +although the other powers are no less required, in order to produce or +modify these great agents in the economy of life, and system of our +changing things. + +We do not now inquire into the nature of those powers, or investigate +the laws of light and heat, of cold and condemnation, by which the +various purposes of this world are accomplished; we are only to mention +those effects which are made sensible to the common understanding of +mankind, and which necessarily imply a power that is employed. Thus, +it is by the operation of those powers that the varieties of season +in spring and autumn are obtained, that we are blessed with the +vicissitudes of summer's heat and winter's cold, and that we possess the +benefit of artificial light and culinary fire. + +We are thus bountifully provided with the necessaries of life; we are +supplied with things conducive to the growth and preservation of our +animal nature, and with fit subjects to employ and to nourish our +intellectual powers. + +There are other actuating powers employed in the operations of this +globe, which we are little more than able to enumerate; such are those +of electricity, magnetism, and subterraneous heat or mineral fire. + +Powers of such magnitude or force, are not to be supposed useless in a +machine contrived surely not without wisdom; but they are mentioned here +chiefly on account of their general effect; and it is sufficient to have +named powers, of which the actual existence is well known, but of which +the proper use in the constitution of the world is still obscure. +The laws of electricity and magnetism have been well examined by +philosophers; but the purposes of those powers in the economy of the +globe have not been discovered. Subterraneous fire, again, although the +most conspicuous in the operations of this world, and often examined by +philosophers, is a power which has been still less understood, whether +with regard to its efficient or final cause. It has hitherto appeared +more like the accident of natural things, than the inherent property of +the mineral region. It is in this last light, however, that I wish to +exhibit it, as a great power acting a material part in the operations of +the globe, and as an essential part in the constitution of this world. + +We have thus surveyed the machine in general, with those moving powers, +by which its operations, diversified almost _ad infinitum_, are +performed. Let us now confine our view, more particularly, to that part +of the machine on which we dwell, that so we may consider the natural +consequences of those operations which, being within our view, we are +better qualified to examine. + +This subject is important to the human race, to the possessor of this +world, to the intelligent being Man, who foresees events to come, and +who, in contemplating his future interest, is led to inquire concerning +causes, in order that he may judge of events which otherwise he could +not know. + +If, in pursuing this object, we employ our skill in research, not in +forming vain conjectures; and if _data_ are to be found, on which +Science may form just conclusions, we should not long remain in +ignorance with respect to the natural history of this earth, a subject +on which hitherto opinion only, and not evidence, has decided: For in no +subject, perhaps, is there naturally less defect of evidence, although +philosophers, led by prejudice, or misguided by false theory, may have +neglected to employ that light by which they should have seen the system +of this world. + +But to proceed in pursuing a little farther our general or preparatory +ideas. A solid body of land could not have answered the purpose of a +habitable world; for, a soil is necessary to the growth of plants; and a +soil is nothing but the materials collected from the destruction of the +solid land. Therefore, the surface of this land, inhabited by man, +and covered with plants and animals, is made by nature to decay, in +dissolving from that hard and, compact state in which it is found below +the soil; and this soil is necessarily washed away, by the continual +circulation of the water, running from the summits of the mountains +towards the general receptacle of that fluid. The heights of our land +are thus levelled with the shores; our fertile plains are formed from the +ruins of the mountains; and those travelling materials are still pursued +by the moving water, and propelled along the inclined surface of the +earth[1] These moveable materials, delivered into the sea, cannot, for +a long continuance, rest upon the shore; for, by the agitation of the +winds, the tides and currents, every moveable thing is carried +farther and farther along the shelving bottom of the sea, towards the +unfathomable regions of the ocean. + +[Note 1: M. de Luc, in his second letter to me, published in the Monthly +Review for 1790, says, "You ought to have proved that both gravel and +sand are carried from our continents to the sea; which, on the contrary, +I shall prove not to be the case." He then endeavours to prove his +assertion, by observing, that, in certain places where there is not +either sufficient declivity in the surface, or force in the running +water, gravel and sand are made to rest, and do not travel to the sea. +This surely is a fact to which I most readily assent; but, on the other +hand, I hope he will acknowledge, that, where there is sufficient +declivity in the surface, or force in the running water, sand, gravel, +and stones, are travelled upon the land, and are thus carried into the +sea--at last. This is all that my theory requires, and this is what I +believe will be admitted, without any farther proof on my part.] + +If the vegetable soil is thus constantly removed from the surface of the +land, and if its place is thus to be supplied from the dissolution of +the solid earth, as here represented, we may perceive an end to this +beautiful machine; an end, arising from no error in its constitution as +a world, but from that destructibility of its land which is so necessary +in the system of the globe, in the economy of life and vegetation. + +The immense time necessarily required for this total destruction of +the land, must not be opposed to that view of future events, which is +indicated by the surest facts, and most approved principles. Time, which +measures every thing in our idea, and is often deficient to our schemes, +is to nature endless and as nothing; it cannot limit that by which alone +it had existence; and, as the natural course of time, which to us seems +infinite, cannot be bounded by any operation that may have an end, the +progress of things upon this globe, that is, the course of nature, +cannot be limited by time, which must proceed in a continual succession. +We are, therefore, to consider as inevitable the deduction of our land, +so far as effected by those operations which are necessary in the +purpose of the globe, considered as a habitable world; and, so far as +we have not examined any other part of the economy of nature, in which +other operations and a different intention might appear. + +We have now considered the globe of this earth as a machine, constructed +upon chemical as well as mechanical principles, by which its different +parts are all adapted, in form, in quality, and in quantity, to a +certain end; an end attained with certainty or success; and an end from +which we may perceive wisdom, in contemplating the means employed. + +But is this world to be considered thus merely as a machine, to last no +longer than its parts retain their present position, their proper forms +and qualities? Or may it not be also considered as an organized body? +such as has a constitution in which the necessary decay of the machine +is naturally repaired, in the exertion of those productive powers by +which it had been formed. + +This is the view in which we are now to examine the globe; to see if +there be, in the constitution of this world, a reproductive operation, +by which a ruined constitution may be again repaired, and a duration or +stability thus procured to the machine, considered as a world sustaining +plants and animals. + +If no such reproductive power, or reforming operation, after due +inquiry, is to be found in the constitution of this world, we should +have reason to conclude, that the system of this earth has either been +intentionally made imperfect, or has not been the work of infinite power +and wisdom. + +Here is an important question, therefore, with regard to the +constitution of this globe; a question which, perhaps, it is in +the power of man's sagacity to resolve; and a question which, if +satisfactorily resolved, might add some lustre to science and the human +intellect. + +Animated with this great, this interesting view, let us strictly examine +our principles, in order to avoid fallacy in our reasoning; and let us +endeavour to support our attention, in developing a subject that is +vast in its extent, as well as intricate in the relation of parts to be +stated. + +The globe of this earth is evidently made for man. He alone, of all the +beings which have life upon this body, enjoys the whole and every part; +he alone is capable of knowing the nature of this world, which he thus +possesses in virtue of his proper right; and he alone can make the +knowledge of this system a source of pleasure, and the means of +happiness. + +Man alone, of all the animated beings which enjoy the benefits of this +earth, employs the knowledge which he there receives, in leading him to +judge of the intention of things, as well as of the means by which they +are brought about; and he alone is thus made to enjoy, in contemplation +as well as sensual pleasure, all the good that may be observed in the +constitution of this world; he, therefore, should be made the first +subject of inquiry. + +Now, if we are to take the written history of man for the rule by which +we should judge of the time when the species first began, that period +would be but little removed from the present state of things. The Mosaic +history places this beginning of man at no great distance; and there +has not been found, in natural history, any document by which a high +antiquity might be attributed to the human race. But this is not the +case with regard to the inferior species of animals, particularly those +which inhabit the ocean and its shores. We find, in natural history, +monuments which prove that those animals had long existed; and we thus +procure a measure for the computation of a period of time extremely +remote, though far from being precisely ascertained. + +In examining things present, we have data from which to reason with +regard to what has been; and, from what has actually been, we have +data for concluding with regard to that which is to happen hereafter. +Therefore, upon the supposition that the operations of nature are +equable and steady, we find, in natural appearances, means for +concluding a certain portion of time to have necessarily elapsed, in the +production of those events of which we see the effects. + +It is thus that, in finding the relics of sea-animals of every kind +in the solid body of our earth, a natural history of those animals +is formed, which includes a certain portion of time; and, for the +ascertaining this portion of time, we must again have recourse to the +regular operations of this world. We shall thus arrive at facts which +indicate a period to which no other species of chronology is able to +remount. + +In what follows, therefore, we are to examine the construction of the +present earth, in order to understand the natural operations of time +past; to acquire principles, by which we may conclude with regard to the +future course of things, or judge of those operations, by which a world, +so wisely ordered, goes into decay; and to learn, by what means such a +decayed world may be renovated, or the waste of habitable land upon the +globe repaired. + +This, therefore, is the object which we are to have in view during this +physical investigation; this is the end to which are to be directed all +the steps in our cosmological pursuit. + +The solid parts of the globe are, in general, composed of sand, of +gravel, of argillaceous and calcareous strata, or of the various +compositions of these with some other substances, which it is not +necessary now to mention. Sand is separated and sized by streams and +currents; gravel is formed by the mutual attrition of stones agitated +in water; and marly, or argillaceous strata, have been collected, by +subsiding in water with which those earthy substances had been floated. +Thus, so far as the earth is formed of these materials, that solid body +would appear to have been the production of water, winds, and tides. + +But that which renders the original of our land clear and evident, +is the immense quantities of calcareous bodies which had belonged +to animals, and the intimate connection of these masses of animal +production with the other strata of the land. For it is to be proved, +that all these calcareous bodies, from the collection of which the +strata were formed, have belonged to the sea, and were produced in it. + +We find the marks of marine animals in the most solid parts of the +earth; consequently, those solid parts have been formed after the ocean +was inhabited by those animals which are proper to that fluid medium. +If, therefore, we knew the natural history of those solid parts, and +could trace the operations of the globe, by which they had been formed, +we would have some means for computing the time through which those +species of animals have continued to live. But how shall we describe a +process which nobody has seen performed, and of which no written +history gives any account? This is only to be investigated, _first_, in +examining the nature of those solid bodies, the history of which we want +to know; and, 2_dly_, In examining the natural operations of the globe, +in order to see if there now actually exist such operations, as, from +the nature of the solid bodies, appear to have been necessary to their +formation. + +But, before entering more particularly into those points of discussion, +by which the question is to be resolved, let us take a general view of +the subject, in order to see what it is which science and observation +must decide. + +In all the regions of the globe, immense masses are found, which, though +at present in the most solid state, appear to have been formed by the +collection of the calcareous _exuviae_ of marine animals. The question +at present is not, in what manner those collections of calcareous relics +have become a perfect solid body, and have been changed from an animal +to a mineral substance; for this is a subject that will be afterwards +considered; we are now only inquiring, if such is truly the origin of +those mineral masses. + +That all the masses of marble or limestone are composed of the +calcareous matter of marine bodies, may be concluded from the following +facts: + +1_st_, There are few beds of marble or limestone, in which may not be +found some of those objects which indicate the marine origin of the +mass. If, for example, in a mass of marble, taken from a quarry upon the +top of the Alps or Andes[2], there shall be found one cockle-shell, or +piece of coral, it must be concluded, that this bed of stone had been +originally formed at the bottom of the sea, as much as another bed which +is evidently composed almost altogether of cockle-shells and coral. If +one bed of limestone is thus found to have been of a marine origin, +every concomitant bed of the same kind must be also concluded to have +been formed in the same Manner. + +[Note 2: "Cette sommite elevee de 984 toises au dessus de notre lac, et +par consequent de 1172 au dessus de la mer, est remarquable en ce que +l'on y voit des fragmens d'huitres petrifies.--Cette montagne est +dominee par un rocher escarpe, qui s'il n'est pas inaccessible, est du +moins d'un bien difficile acces; il paroit presqu'entierement compose +de coquillages petrifies, renfermes dans un roc calcaire, ou marbre +grossier noiratre. Les fragmens qui s'en detachent, et que l'on +rencontre en montant a la Croix de fer, sont remplis de _turbinites_ de +differentes especes." M. DE SAUSSURE, _Voyage dans les Alpes_, p. 394.] + +We thus shall find the greatest part of the calcareous masses upon this +globe to have originated from marine calcareous bodies; for whether +we examine marbles, limestones, or such solid masses as are perfectly +changed from the state of earth, and are become compact and hard, or +whether we examine the soft, earthy, chalky or marly strata, of which so +much of this earth is composed, we still find evident proofs, that those +beds had their origin from materials deposited at the bottom of the sea; +and that they have the calcareous substance which they contain, from the +same source as the marbles or the limestones. + +2_dly_, In those calcareous strata, which are evidently of marine +origin, there are many parts that are of a sparry structure, that is +to say, the original texture of those beds, in such places, has been +dissolved, and a new structure has been assumed, which is peculiar to +a certain state of the calcareous earth. This change is produced by +crystallisation, in consequence of a previous state of fluidity, which +has so disposed the concreting parts, as to allow them to assume a +regular shape and structure proper to that substance. A body, whose +external form has been modified by this process, is called a _crystal_; +one whose internal arrangement of parts is determined by it, is said to +be of a _sparry structure_; and this is known from its fracture. + +3_dly_, There are, in all the regions of the earth, huge masses of +calcareous matter, in that crystalline form of sparry state, in +which perhaps no vestige can be found of any organised body, nor any +indication that such calcareous matter had belonged to animals; but +as, in other masses, this sparry structure, or crystalline state, is +evidently assumed by the marine calcareous substances, in operations +which are natural to the globe, and which are necessary to the +consolidation of the strata, it does not appear, that the sparry masses, +in which no figured body is formed, have been originally different from +other masses, which, being only crystallised in part, and in part still +retaining their original form, leave ample evidence of their marine +origin[3]. + +[Note 3: M. de Saussure, describing the marble of Aigle, says, "Les +tables polies de ce marbre presentent frequemment des coquillages, dont +la plupart sont des peignes stries, et de tres-beaux madrepores. Tous +ces corps marins on pris entierement la nature et le grain meme +du marbre, on n'y voit presque jamais la coquille sous sa forme +originaire."] + +We are led, in this manner, to conclude, that all the strata of the +earth, not only those consisting of such calcareous masses, but others +superincumbent upon these, have had their origin at the bottom of the +sea, by the collection of sand and gravel, of shells, of coralline +and crustaceous bodies, and of earths and clays, variously mixed, +or separated and accumulated. Here is a general conclusion, well +authenticated in the appearances of nature, and highly important in the +natural history of the earth. + +The general amount of our reasoning is this, that nine-tenths, perhaps, +or ninety-nine hundredths of this earth, so far as we see, have +been formed by natural operations of the globe, in collecting loose +materials, and depositing them at the bottom of the sea; consolidating +those collections in various degrees, and either elevating those +consolidated masses above the level on which they were formed, or +lowering the level of that sea. + +There is a part of the solid earth which we may at present neglect, not +as being persuaded that this part may not also be found to come under +the general rule of formation with the rest, but as considering this +part to be of no consequence in forming a general rule, which shall +comprehend almost the whole, without doing it absolutely. This excluded +part consists of certain mountains and masses of granite. These are +thought to be still older in their formation, and are said never to +be found superincumbent on strata which must be acknowledged as the +productions of the sea. + +Having thus found the greater part, if not the whole, of the solid land +to have been originally composed at the bottom of the sea, we may now, +in order to form a proper idea of these operations, suppose the whole of +this seaborn land to be again dispersed along the bottom of the ocean, +the surface of which would rise proportionally over the globe. We would +thus have a spheroid of water, with granite rocks and islands scattered +here and there. But this would not be the world which we inhabit; +therefore, the question now is, how such continents, as we actually have +upon the globe, could be erected above the level of the sea. + +It must be evident, that no motion of the sea, caused by this earth +revolving in the solar system, could bring about that end; for let us +suppose the axis of the earth to be changed from the present poles, and +placed in the equinoctial line, the consequence of this might, indeed, +be the formation of a continent of land about each new pole, from whence +the sea would run towards the new equator; but all the rest of the globe +would remain an ocean. Some new points might be discovered, and others, +which before appeared above the surface of the sea, would be sunk by +the rising of the water; but, on the whole, land could only be gained +substantially at the poles. Such a supposition, as this, if applied to +the present state of things, would be destitute of every support, as +being incapable of explaining what appears. + +But even allowing that, by the changed axis of the earth, or any other +operation of the globe, as a planetary body revolving in the solar +system, great continents of land could have been erected from the place +of their formation, the bottom of the sea, and placed in a higher +elevation, compared with the surface of that water, yet such a continent +as this could not have continued stationary for many thousand years; nor +could a continent of this kind have presented to us, every where within +its body, masses of consolidated marble, and other mineral substances, +in a state as different as possible from that in which they were, when +originally collected together in the sea. + +Consequently, besides an operation, by which the earth at the bottom of +the sea should be converted into an elevated land, or placed high above +the level of the ocean, there is required, in the operations of the +globe, a consolidating power, by which the loose materials that had +subsided from water, should be formed into masses of the most perfect +solidity, having neither water nor vacuity between their various +constituent parts, nor in the pores of those constituent parts +themselves. + +Here is an operation of the globe, whether chemical or mechanical, which +is necessarily connected with the formation of our present continents: +Therefore, had we a proper understanding of this secret operation, we +might thereby be enabled to form an opinion, with regard to the nature +of that unknown power, by which the continents have been placed above +the surface of that water wherein they had their birth. + +If this consolidating operation be performed at the bottom of the +ocean, or under great depths of the earth, of which our continents are +composed, we cannot be witnesses to this mineral process, or acquire the +knowledge of natural causes, by immediately observing the changes which +they produce; but though we have not this immediate observation of those +changes of bodies, we have, in science, the means of reasoning from +distant events; consequently, of discovering, in the general powers of +nature, causes for those events of which we see the effects. + +That the consolidating operation, in general, lies out of the reach of +our immediate observation, will appear from the following truth: All the +consolidated masses, of which we now inquire into the cause, are, upon +the surface of the earth, in a state of general decay, although the +various natures of those bodies admit of that dissolution in very +different degrees[4] + +From every view of the subject, therefore, we are directed to look into +those consolidated masses themselves, in order to find principles from +whence to judge of those operations by which they had attained their +hardness or consolidated state. + +It must be evident, that nothing but the most general acquaintance with +the laws of acting substances, and with those of bodies changing by the +powers of nature, can enable us to set about this undertaking with any +reasonable prospect of success; and here the science of Chemistry must +be brought particularly to our aid; for this science, having for its +object the changes produced upon the sensible qualities, as they are +called, of bodies, by its means we may be enabled to judge of that which +is possible according to the laws of nature, and of that which, in like +manner, we must consider as impossible. + +[Note 4: Stalactical and certain ferruginous concretions may seem +to form an exception to the generality of this proposition. But an +objection of this kind could only arise from a partial view of things; +for the concretion here is only temporary; it is in consequence of a +solution, and it is to be followed by a dissolution, which will be +treated of in its proper place.] + +Whatever conclusions, therefore, by means of this science, shall be +attained, in just reasoning from natural appearances, this must be held +as evidence, where more immediate proof cannot be obtained; and, in +a physical subject, where things actual are concerned, and not the +imaginations of the human mind, this proof will be considered as +amounting to a demonstration. + + +SECTION II. + +An Investigation of the Natural Operations employed in consolidating +the Strata of the Globe. + +We are now about to investigate those mineral operations of the globe by +which the qualities of hardness and solidity, consequently of strength +and durability, are procured to great bodies of this earth. + +That those qualities are not original to such bodies, but actually +superinduced in the natural operations of the earth, will appear from +the examination of some of the hardest and most solid of those mineral +bodies. In such masses, (for example of flint and agate,) we find +included shells and coralline bodies. Consequently, there must be a +natural operation in the globe for consolidating and hardening its soft +and loose materials. It is concerning the nature of this consolidating +operation that we are now to inquire. + +There are just two ways in which porous or spongy bodies can be +consolidated, and by which substances may be formed into masses of +a natural shape and regular structure; the one of these is simple +_congelation_ from a fluid state, by means of cold; the other is +_accretion_; and this includes a separatory operation, as well as that +by which the solid body is to be produced. But in whichever of these +ways solidity shall be procured, it must be brought about by first +inducing fluidity, either immediately by the action of heat, or +mediately with the assistance of a solvent, that is, by the operation +of solution. Therefore, fire and water may be considered as the general +agents in this operation, which we would explore. + +Heat has been already mentioned as a general power, and as acting in all +the different parts of the globe; I would now wish more particularly to +call the attention of the reader to subterraneous fire, or heat, as +a powerful agent in the mineral regions, and as a cause necessarily +belonging to the internal constitution of this earth. + +It is not our purpose at present to inquire into the particular nature +of this power of subterraneous heat, or to trace the proper connection +and analogy of the internal fire with that which is so necessary to our +life, and which acts so great a part upon the surface of the earth, this +being reserved for the last part. Our intention in here mentioning it, +is only to dispose the mind to look for active powers or efficient +causes, in that part of the earth which has been commonly considered as +passive and inert, but which will be found extremely active, and the +source of mighty revolutions in the fate of land. + +There may, indeed, be some difficulty in conceiving all the +modifications of this mineral power; but as, on the one hand, we are not +arbitrarily to assume an agent, for the purpose of explaining events, or +certain appearances which are not understood; so, on the other, we must +not refuse to admit the action of a known power, when this is properly +suggested in the appearances of things; and, though we may not +understand all the modifications, or the whole capacity and regulation +of this power in bodies, we are not to neglect the appropriating to it, +as a cause, those effects which are natural to it, and which, so far as +we know, cannot belong to any other. On all occasions, we are to judge +from what we know; and, we are only to avoid concluding from our +suppositions, in cases where evidence or real information is necessarily +required. The subject now considered, subterraneous fire, will afford an +example of that truth; and, a general view of this great natural power +will here find a proper place, before the application of it for the +explanation of natural appearances. + +No event is more the object of our notice, or more interesting as a +subject for our study, than is the burning of a fire: But, the more that +philosophers have studied this subject, the more they seem to differ +as to the manner in which that conspicuous event is to be explained. +Therefore, being so ignorant with regard to that fire of which we see +the origin as well as the more immediate effects, how cautious should +we be in judging the nature of subterraneous fire from the burning of +bodies, a subject which we so little understand. + +But, though the cause of fire in general, or the operations of that +power in its extreme degrees, be for us a subject involved in much +obscurity, this is not the case with regard to the more common effects +of heat; and, tho' the actual existence of subterraneous fire, as the +cause of light and heat, might be a thing altogether problematical in +our opinion; yet, as to other effects, there are some of these from +which the action of that liquefying power may be certainly concluded as +having taken place within the mineral region, although the cause should +be in every other respect a thing to us unknown. In that case, where the +operation or effect is evident, and cannot be disputed, to refuse to +admit the power in question, merely because we had not seen it act, or +because we know not every rule which it may observe in acting, would +be only to found an argument upon our ignorance; it would be to +misunderstand the nature of investigating physical truths, which must +proceed by reasoning from effect to cause. + +Our knowledge is extremely limited with regard to the effects of heat in +bodies, while acting under different conditions, and in various degrees. +But though our knowledge in these respects is limited, our judgment with +regard to the efficacy of this power of heat is in its nature positive, +and contains not any thing that is doubtful or uncertain. All mankind, +who have the opportunity, know that the hard substance of ice is by heat +converted into water, wherein no hardness remains; and the profound +philosophy of Dr Black, in relation to the subject of _latent heat_, as +that of Sir Isaac Newton, in relation to the weight of bodies, is not +necessary to convince the world that in the one case ice will melt, and +in the other, that heavy bodies will move when unsupported. + +But though, in the abstract doctrine of _latent heat_, the ingenuity +of man has discovered a certain measure for the quantity of those +commutable effects which are perceived; and though this be a progress of +science far above the apprehension of the vulgar, yet still, that solid +bodies are changed into fluids, by the power of heat, is the same +unalterable judgment, which the savage forms as well as the philosopher. +Here, therefore, are evident effects, which mankind in general attribute +to the power of heat; and it is from those known effects that we are to +investigate subterraneous fire, or to generalise the power of heat, as +acting in the interior parts, as well as on the surface of this earth. + +If, indeed, there were any other cause for fluidity besides the +operation of fire or the power of heat, in that case the most evident +proof, with regard to the flowing, or former fluidity, of mineral +bodies, would draw to no conclusion in proving the existence of mineral +fire; but when we have not the smallest reason for conjecturing any +other cause, or the least doubt with regard to that which, in the +doctrine of latent heat, has been properly investigated, the proofs +which we shall bring, of fusion in all the minerals of this earth, +must be held as proofs of mineral fire, in like manner as the proof of +subterraneous fire would necessarily imply mineral fusion as its natural +effect. + +Thus we have, in our physical investigation, several points in view. +First, from the present state of things, to infer a former state of +fusion among mineral bodies. Secondly, from that former fusion, to infer +the actual existence of mineral fire in the system of the earth. And, +lastly, from the acknowledged fact of subterraneous fire as a cause, to +reason with regard to the effects of that power in mineral bodies. + +But besides the power or effect of subterraneous heat in bodies which +are unorganised, and without system, in the construction of their +different parts, we have to investigate the proper purpose of this great +agent in the system of this world, which may be considered as a species +of organised body. Here, therefore, final causes are to be brought into +view, as well as those which are efficient. Now, in a subject involved +with so much obscurity, as must be for us the internal regions of the +globe, the consideration of efficient and final causes may contribute +mutually to each others evidence, when separately the investigation of +either might be thought unsatisfactory or insufficient. + +So far it seemed necessary to premise with regard to the great mineral +power which we are to employ as an agent in the system of this earth; +and it may be now observed, that it is in the proper relation of this +power of heat and the fluidity or softness of bodies, as cause and +effect, that we are to find a physical principle or argument for +detecting those false theories of the earth that have been only +imagined, and not properly founded on fact or observation. It is also by +means of this principle, that we shall be enabled to form a true theory +of the mineral region, in generalising particular effects to a common +cause. + +Let us now proceed in endeavouring to decide this important question, +viz. By what active principle is it, that the present state of things, +which we observe in the strata of the earth, a state so very different +from that in which those bodies had been formed originally, has been +brought about? + +Two causes have been now proposed for the consolidating of loose +materials which had been in an incoherent state; these are, on the one +hand, fire; or, on the other, water, as the means of bringing about that +event. We are, therefore, to consider well, what may be the consequences +of consolidation by the one or other of those agents; and what may be +the respective powers of those agents with respect to this operation. + +If we are not informed in this branch of science, we may gaze without +instruction upon the most convincing proofs of what we want to attain. +If our knowledge is imperfect, we may form erroneous principles, and +deceive ourselves in reasoning with regard to those works of nature, +which are wisely calculated for our instruction. + +The strata, formed at the bottom of the sea, are to be considered +as having been consolidated, either by aqueous solution and +crystallization, or by the effect of heat and fusion. If it is in the +first of these two ways that the solid strata of the globe have attained +to their present state, there will be a certain uniformity observable +in the effects; and there will be general laws, by which this operation +must have been conducted. Therefore, knowing those general laws, and +making just observations with regard to the natural appearances of those +consolidated masses, a philosopher, in his closet, should be able to +determine, what may, and what may not have been transacted in the bowels +of the earth, or below the bottom of the ocean. + +Let us now endeavour to ascertain what may have been the power of water, +acting under fixed circumstances, operating upon known substances, and +conducting to a certain end. + +The action of water upon all different substances is an operation +with which we are familiar. We have it in our power to apply water in +different degrees of heat for the solution of bodies, and under various +degrees of compression; consequently, there is no reason to conclude +any thing mysterious in the operations of the globe, which are to be +performed by means of water, unless an immense compressing power should +alter the nature of those operations. But compression alters the +relation of evaporation only with regard to heat, or it changes the +degree of heat which water may be made to sustain; consequently, we are +to look for no occult quality in water acting upon bodies at the bottom +of the deepest ocean, more than what can be observed in experiments +which we have it in our power to try. + +With regard again to the effect of time: Though the continuance of time +may do much in those operations which are extremely slow, where no +change, to our observation, had appeared to take place, yet, where it +is not in the nature of things to produce the change in question, the +unlimited course of time would be no more effectual, than the moment by +which we measure events in our observations. + +Water being the general medium in which bodies collected at the bottom +of the sea are always contained, if those masses of collected matter are +to be consolidated by solution, it must be by the dissolution of +those bodies in that water as a menstruum, and by the concretion or +crystallization of this dissolved matter, that the spaces, first +occupied by water in those masses, are afterwards to be filled with a +hard and solid substance; but without some other power, by which the +water contained in those cavities and endless labyrinths of the strata, +should be separated in proportion as it had performed its task, it is +inconceivable how those masses, however changed from the state of their +first subsidence, should be absolutely consolidated, without any visible +or fluid water in their composition. + +Besides this difficulty of having the water separated from the porous +masses which are to be consolidated, there is another with which, upon +this supposition, we have to struggle. This is, From whence should come +the matter with which the numberless cavities in those masses are to be +filled? + +The water in the cavities and interstices of those bodies composing +strata, must be in a stagnating state; consequently, it can only act +upon the surfaces of those cavities which are to be filled up. But +with what are they to be filled? Not with water; they are full of that +already: Not with the substance of the bodies which contain that water; +this would be only to make one cavity in order to fill up another. +If, therefore, the cavities of the strata are to be filled with solid +matter, by means of water, there must be made to pass through those +porous masses, water impregnated with some other substances in a +dissolved state; and the aqueous menstruum must be made to separate +from the dissolved substance, and to deposit the same in those cavities +through which the solution moves. + +By such a supposition as this, we might perhaps explain a partial +consolidation of those strata; but this is a supposition, of which the +case under consideration does not admit; for in the present case, which +is that of materials accumulated at the bottom of the ocean, there is +not proper means for separating the dissolved matter from the water +included in those enormous masses; nor are there any means by which a +circulation in those masses may be formed. In this case, therefore, +where the means are not naturally in the supposition, a philosopher, who +is to explain the phenomenon by the natural operation of water in this +situation, must not have recourse to another agent, still more powerful, +to assist his supposition which cannot be admitted. + +Thus, it will appear, that, to consolidate strata formed at the bottom +of the sea, in the manner now considered, operations are required +unnatural to this place; consequently, not to be supposed, in order to +support a hypothesis. + +But now, instead of inquiring how far water may be supposed instrumental +in the consolidation of strata which were originally of a loose +texture, we are to consider how far there may be appearances in those +consolidated bodies, by which it might be concluded, whether or not the +present state of their consolidation has been actually brought about by +means of that agent. + +If water had been the menstruum by which the consolidating matter was +introduced into the interstices of strata, masses of those bodies could +only be found consolidated with such substances as water is capable of +dissolving; and these substances would be found only in such a state as +the simple separation of the solvent water might produce. + +In this case, the consolidation of strata would be extremely limited; +for we cannot allow more power to water than we find it has in nature; +nor are we to imagine to ourselves unlimited powers in bodies, on +purpose to explain those appearances by which we should be made to know +the powers of nature. Let us, therefore, attend, with every possible +circumspection, to the appearances of those bodies, by means of which we +are to investigate the principles of mineralogy, and know the laws of +nature. + +The question now before us concerns the consolidating substances of +strata. Are these such as will correspond to the dissolving power of +water, and to the state in which these substances might be left by the +separation of their menstruum? No; far, far from this supposition is the +conclusion that necessarily follows from natural appearances. + +We have strata consolidated by calcareous spar, a thing perfectly +distinguishable from the stalactical concretion of calcareous earth, +in consequence of aqueous solution. We have strata made solid by the +formation of fluor, a substance not soluble, so far as we know, by +water. We have strata consolidated with sulphureous and bituminous +substances, which do not correspond to the solution of water. We have +strata consolidated with siliceous matter, in a state different from +that under which it has been observed, on certain occasions, to be +deposited by water. We have strata consolidated by feld-spar, a +substance insoluble in water. We have strata consolidated by almost all +the various metallic substances, with their almost endless mixtures +and sulphureous compositions; that is to say, we find, perhaps, every +different substance introduced into the interstices of strata which had +been formed by subsidence at the bottom of the sea. + +If it is by means of water that those interstices have been filled with +those materials, water must be, like fire, an universal solvent, or +cause of fluidity, and we must change entirely our opinion of water in +relation to its chemical character. But there is no necessity thus to +violate our chemical principles, in order to explain certain natural +appearances; more especially if those appearances may be explained in +another manner, consistently with the known laws of nature. + +If, again, it is by means of heat and fusion that the loose and porous +structure of strata shall be supposed to have been consolidated, then +every difficulty which had occurred in reasoning upon the power or +agency of water is at once removed. The loose and discontinuous body of +a stratum may be closed by means of softness and compression; the porous +structure of the materials may be consolidated, in a similar manner, by +the fusion of their substance; and foreign matter may be introduced into +the open structure of strata, in form of steam or exhalation, as well as +in the fluid state of fusion; consequently, heat is an agent competent +for the consolidation of strata, which water alone is not. If, +therefore, such an agent could be found acting in the natural place of +strata, we must pronounce it proper to bring about that end. + +The examination of nature gives countenance to this supposition, so far +as strata are found consolidated by every species of substance, +and almost every possible mixture of those different substances; +consequently, however difficult it may appear to have this application +of heat, for the purpose of consolidating strata formed at the bottom of +the ocean, we cannot, from natural appearances, suppose any other cause, +as having actually produced the effects which are now examined. + +This question, with regard to the means of consolidating the strata of +the globe, is, to natural history, of the greatest importance; and it is +essential in the theory now proposed to be given of the mineral system. +It would, therefore, require to be discussed with some degree of +precision in examining the particulars; but of these, there is so great +a field, and the subject is so complicated in its nature, that volumes +might be written upon particular branches only, without exhausting what +might be laid upon the subject; because the evidence, though strong in +many particulars, is chiefly to be enforced by a multitude of facts, +conspiring, in a diversity of ways, to point out one truth, and by the +impossibility of reconciling all these facts, except by means of one +supposition. + +But, as it is necessary to give some proof of that which is to be +a principle in our reasoning afterwards, I shall now endeavour to +generalise the subject as much as possible, in order to answer that end, +and, at the same time, to point out the particular method of inquiry. + +There are to be found, among the various strata of the globe, bodies +formed of two different kinds of substances, _siliceous_ bodies, and +those which may be termed _sulphureous_ or _phlogistic_. With one or +other, or both of those we substances, every different consolidated +stratum of the globe will be found so intimately mixed, or closely +connected, that it must be concluded, by whatever cause those bodies +of siliceous and sulphureous matter had been changed from a fluid to a +concreted state, the strata must have been similarly affected by the +same cause. + +These two species of bodies, therefore, the siliceous and the +sulphureous, may now be examined, in relation to the causes of their +concretion, with a view to determine, what has been the general +concreting or consolidating power, which has operated universally in the +globe; and particularly to show, it has not been by means of any fluid +solution, that strata in general have been consolidated, or that those +particular substances have been crystallized and concreted. + +Siliceous matter, physically speaking, is not soluble in water; that is +to say, in no manner of way have we been enabled to learn, that water +has the power of dissolving this matter. + +Many other substances, which are so little soluble in water, that their +solubility could not be otherwise detected of themselves, are made to +appear soluble by means of siliceous matter; such is feld-spar, one of +the component parts of rock-granite. + +Feld-spar is a compound of siliceous, argillaceous, and calcareous +earth, intimately united together. This compound siliceous body +being, for ages, exposed to the weather, the calcareous part of it is +dissolved, and the siliceous part is left in form of a soft white earth. +But whether this dissolution is performed by pure water, or by means +also of an acid, may perhaps be questioned. This, however, is certain, +that we must consider siliceous substances as insoluble in water. + +The water of Glezer in Iceland undoubtedly contains this substance in +solution; but there is no reason to believe, that it is here dissolved +by any other than the natural means; that is, an alkaline substance, by +which siliceous bodies may be rendered soluble in water[5]. + +[Note 5: This conjecture, which I had thus formed, has been fully +confirmed by the accurate analysis of those waters. See vol. 3d. of the +Phil. Trans. of Edin.] + +It may be, therefore, asserted, that no siliceous body having the +hardness of flint, nor any crystallization of that substance, has ever +been formed, except by fusion. If, by any art, this substance shall be +dissolved in simple water, or made to crystallise from any solution, in +that case, the assertion which has been here made may be denied. +But where there is not the vestige of any proof, to authorise the +supposition of flinty matter being dissolved by water, or crystallized +from that solution, such an hypothesis cannot be admitted, in opposition +to general and evident appearances[6]. + +[Note 6: The Chevalier de Dolomieu has imagined an ingenious theory for +the solution of siliceous substances in water [Journal de Physique, Mai +1792.]. This theory has not been taken up merely at a venture, but +is founded upon very accurate and interesting chemical experiments. +Hitherto, however, the nature of the siliceous substance is not +sufficiently known, to enable us to found, upon chemical principles, the +mineral operations of nature. That siliceous substance may be dissolved, +or rendered soluble in water, by means of alkaline salt, and that it may +be also volatilised by means of the fluor acid, is almost all that we +know upon the subject. But this is saying no more in relation to the +mineral operations employed upon the siliceous substance, than it would +be, in relation to those upon gold, to say that this metal is dissolved +by aqua regia. + +It is to be admitted, that every simple substance may have its +menstruum, by means of which it may be retained with water in a +dissolved state; but from this it does not follow, that it is by the +means of aqueous solutions of all those mineral bodies, that nature +operates the consolidation of bodies, which we find actually +accomplished with all those different substances. It is the business of +this work to show, that from all appearances in the mineral regions, as +well as those upon the surface in the atmosphere, the supposition, of +that manner of consolidating bodies by solution, is inconsistent both +with natural appearances, and also with chemical principles. + +Our ingenious author, who has, with, great diligence as well as an +enlightened mind, observed the operations of nature upon the surface +of the earth, here says, "ce n'est pas sans etonnement que je remarque +depuis long-temps que jamais aucune eau qui coule a la surface de la +terre n'attaque le quartz, aucune n'en tient en dissolution, pendant que +celles qui circulent interieurement le corrodent aussi souvent qu'elles +le deposent."--How dangerous it is in science for ingenious men to allow +themselves to form conclusions, which the principles on which they +reason do not strictly warrant, we have a remarkable example in the +present case. + +M. de Dolomieu sees no corrosion of quartz, or solution of that +substance, upon the surface of the earth; from this, then, he concludes, +that siliceous substance is not dissolved in that situation of things. +On the other hand, he finds siliceous bodies variously concreted among +the solid strata of the earth; and, from this he concludes, that +siliceous substance has been both dissolved by water in the strata, and +also there again concreted and crystallised in having been separated +from the water. This is certainly what we all perceive; but we do not +all allow ourselves to draw such inconclusive inferences from our +premises. Notwithstanding the greatest accuracy of our observations, +quartz may be dissolvable in a minute degree by water, upon the surface +of this earth; and, all the appearances of siliceous bodies, in the +mineral regions, where we cannot immediately see the operation, may be +better explained by fusion than by aqueous solution. + +But, from his chemical experiments, our author has conjectured that +there may be a phlogistic substance, by means of which the siliceous +earth is dissolved when in darkness; and that this solvent loses its +power, if exposed to the light of day. I have one observation to oppose +to this ingenious theory. Under deep black mosses, through which no ray +of light can penetrate, every condition for dissolving siliceous bodies +should be found, according to the supposition in question; neither will +sufficient time be found wanting, in those deep mosses, upon the summits +of our mountains; yet, examine the matter of fact? not the smallest +solution is to be perceived in the siliceous parts of the stones which +are found under those mosses, but every particle of iron is dissolved, +so that the surface of every stone is white, and nothing but the +siliceous earth of the feld-spar, and perhaps the argillaceous, is left. + +Here we have in this author an instructive example: No person, in my +opinion, has made such enlightened or scientific experiments, or such +judicious observations with regard to the nature of siliceous substance, +as a compound thing; no person reasons more distinctly in general, or +sees more clearly the importance of his principles; yet, with regard to +mineral concretions, how often has he been drawn thus inadvertently +into improper generalization! I appeal to the analogy which, in this +treatise, he has formed, between the stalactical concretions upon +the surface of the earth, and the mineral concretions of siliceous +substance. As an example of the great lights, and penetrating genius, of +this assiduous studier of nature, I refer to the judicious observations +which he has made upon the subject of aluminous earth, in this +dissertation. + +I am surprised to find this enlightened naturalist seeking, in the +origin of this globe of our earth, a general principle of fluidity or +solution in water, like the alkahest of the alchymists, by means of +which the different substances in the chemical constitution of precious +stones might have been united as well as crystallised. One would +have thought, that a philosopher, so conversant in the operations of +subterraneous fire, would have perceived, that there is but one general +principle of fluidity or dissolution, and that this is heat.] + +Besides this proof for the fusion of siliceous bodies, which is +indirect, arising from the in dissolubility of that substance in water, +there is another, which is more direct, being founded upon appearances +which are plainly inconsistent with any other supposition, except that +of simple fluidity induced by heat. The proof I mean is, the penetration +of many bodies with a flinty substance, which, according to every +collateral circumstance, must have been performed by the flinty matter +in a simply fluid state, and not in a state of dissolution by a solvent. + +These are flinty bodies perfectly insulated in strata both of chalk and +sand. It requires but inspection to be convinced. It is not possible +that flinty matter could be conveyed into the middle of those strata, by +a menstruum in which it was dissolved, and thus deposited in that place, +without the smallest trace of deposition in the surrounding parts. + +But, besides this argument taken from what does not appear, the actual +form in which those flinty masses are found, demonstrates, _first_, +That they have been introduced among those strata in a fluid state, by +injection from some other place. 2_dly_, That they have been dispersed +in a variety of ways among those strata, then deeply immersed at the +bottom of the sea; and, _lastly_, That they have been there congealed +from the state of fusion, and have remained in that situation, while +those strata have been removed from the bottom of the ocean to the +surface of the present land. + +To describe those particular appearances would draw this paper beyond +the bounds of an essay. We must, therefore, refer those who would +inquire more minutely into the subject, to examine the chalk-countries +of France and England, in which the flint is found variously formed; the +land-hills interspersed among those chalk-countries, which have been +also injected by melted flint; and the pudding-stone of England, which +I have not seen in its natural situation. More particularly, I would +recommend an examination of the insulated masses of stone, found in +the sand-hills by the city of Brussels; a stone which is formed by an +injection of flint among sand, similar to that which, in a body of +gravel, had formed the pudding-stone of England[7]. + +[Note 7: Accurate descriptions of those appearances, with drawings, +would be, to natural history, a valuable acquisition.] + +All these examples would require to be examined upon the spot, as a +great part of the proof for the fusion of the flinty substance, arises, +in my opinion, from the form in which those bodies are found, and the +state of the surrounding parts. But there are specimens brought from +many different places, which contain, in themselves, the most evident +marks of this injection of the flinty substance in a fluid state. These +are pieces of fossil wood, penetrated with a siliceous substance, which +are brought from England, Germany, and Lochneagh in Ireland. + +It appears from these specimens, that there has sometimes been a prior +penetration of the body of wood, either with irony matter, or calcareous +substance. Sometimes, again, which is the case with that of Lochneagh, +there does not seem to have been any penetration of those two +substances. The injected flint appears to have penetrated the body +of this wood, immersed at the bottom of the sea, under an immense +compression of water. This appears from the wood being penetrated +partially, some parts not being penetrated at all. + +Now, in the limits between those two parts, we have the most convincing +proofs, that it had been flint in a simple fluid state which had +penetrated the wood, and not in a state of solution. + +_First_, Because, however little of the wood is left unpenetrated, the +division is always distinct between the injected part and that which is +not penetrated by the fluid flint. In this case, the flinty matter has +proceeded a certain length, which is marked, and no farther; and, beyond +this boundary, there is no partial impregnation, nor a gradation of the +flintifying operation, as must have been the case if siliceous matter +had been deposited from a solution. 2_dly_, The termination of the +flinty impregnation has assumed such a form, precisely, as would +naturally happen from a fluid flint penetrating that body. + +In other specimens of this mineralising operation, fossil wood, +penetrated, more or less, with ferruginous and calcareous substances, +has been afterwards penetrated with a flinty substance. In this case, +with whatever different substances the woody body shall be supposed +to have been penetrated in a state of solution by water, the regular +structure of the plant would still have remained, with its vacuities, +variously filled with the petrifying substances, separated from the +aqueous menstruum, and deposited in the vascular structure of the wood. +There cannot be a doubt with regard to the truth of this proposition; +for, as it is, we frequently find parts of the consolidated wood, with +the vascular structure remaining perfectly in its natural shape and +situation; but if it had been by aqueous solution that the wood had been +penetrated and consolidated, all the parts of that body would be found +in the same natural shape and situation. + +This, however, is far from being the case; for while, in some parts, the +vascular structure is preserved entire, it is also evident, that, in +general, the woody structure is variously broken and dissolved by the +fusion and crystallization of the flint. There are so many and such +various convincing examples of this, that, to attempt to describe them, +would be to exceed the bounds prescribed for this dissertation; but such +specimens are in my possession, ready for the inspection of any person +who may desire to study the subject. + +We may now proceed to consider sulphureous substances, with regard to +their solubility in water, and to the part which these bodies have acted +in consolidating the strata of the globe. + +The sulphureous substances here meant to be considered, are substances +not soluble in, water, so far as we know, but fusible by heat, and +inflammable or combustible by means of heat and vital air. These +substances are of two kinds; the one more simple, the other more +compound. + +The most simple kind is composed of two different substances, viz. +phlogiston, with certain specific substances; from which result, on the +one hand, sulphur, and, on the other, proper coal and metals. The more +compound sort, again, is oily matter, produced by vegetables, and +forming bituminous bodies. + +The _first_ of these is found naturally combined with almost all +metallic substances, which are then said to be mineralised with sulphur. +Now, it is well known, that this mineralising operation is performed by +means of heat or fusion; and there is no person skilled in chemistry +that will pretend to say, this may be done by aqueous solution. The +combination of iron and sulphur, for example, may easily be performed by +fusion; but, by aqueous solution, this particular combination is again +resolved, and forms an acido-metallic, that is, a vitriolic substance, +after the phlogiston (by means of which it is insoluble in water) has +been separated from the composition, by the assistance of vital air. + +The variety of these sulphureo-metallic substances, in point of +composition, is almost indefinite; but, unless they were all soluble in +water, this could not have happened by the action of that solvent. If we +shall allow any one of those bodies to have been formed by the fluidity +of heat, they must all have been formed in the same manner; for there is +such a chain of connection among those bodies in the mineral regions, +that they must all have been composed, either, on the one hand, by +aqueous solution, or, on the other, by means of heat and fusion. + +Here, for example, are crystallised together in one mass, 1_st, +Pyrites_, containing sulphur, iron, copper; 2_dly, Blend_, a composition +of iron, sulphur, and calamine; 3_dly, Galena_, consisting of lead +and sulphur; 4_thly, Marmor metallicum_, being the terra ponderosa, +saturated with the vitriolic acid; a substance insoluble in water; +5_thly, Fluor_, a saturation of calcareous earth, with a peculiar acid, +called the _acid of spar_, also insoluble in water; 6_thly, Calcareous +spar_, of different kinds, being calcareous earth saturated with fixed +air, and something besides, which forms a variety in this substance; +_lastly, Siliceous substance_, or _Quartz crystals_. All these bodies, +each possessing its proper shape, are mixed in such a manner as it would +be endless to describe, but which may be expressed in general by saying, +that they are mutually contained in, and contain each other. + +Unless, therefore; every one of these different substances may be +dissolved in water, and crystallised from it, it is in vain to look for +the explanation of these appearances in the operations of nature, by the +means of aqueous solution. + +On the other hand, heat being capable of rendering all these substances +fluid, they may be, with the greatest simplicity, transported from one +place to another; and they may be made to concrete altogether at +the same time, and distinctly separate in any place. Hence, for the +explanation of those natural appearances, which are so general, no +further conditions are required, than the supposition of a sufficient +intensity of subterraneous fire or heat, and a sufficient degree of +compression upon those bodies, which are to be subjected to that violent +heat, without calcination or change. But, so far as this supposition is +not gratuitous, the appearances of nature will be thus explained. + +I shall only mention one specimen, which must appear most decisive +of the question. It is, I believe, from an Hungarian mine. In this +specimen, petro-silex, pyrites, and cinnabar, are so mixed together, and +crystallised upon each other, that it is impossible to conceive any one +of those bodies to have had its fluidity and concretion from a cause +which had not affected the other two. Now, let those who would deny the +fusion of this siliceous body explain how water could dissolve these +three different bodies, and deposit them in their present shape. If, +on the contrary, they have not the least shadow of reason for such a +gratuitous supposition, the present argument must be admitted in its +full force. + +Sulphur and metals are commonly found combined in the mineral regions. +But this rule is not universal; for they are also frequently in a +separate state. There is not, perhaps, a metal, among the great number +which are now discovered, that may not be found native, as they are +called, or in their metallic state. + +Metallic substances are also thus found in some proportion to the +disposition of the particular metals, to resist the mineralising +operations, and to their facility of being metallised by fire and +fusion. Gold, which refuses to be mineralised with sulphur, is found +generally in its native state. Iron, again, which is so easily +mineralised and scorified, is seldom found in its malleable state. The +other metals are all found more or less mineralised, though some of them +but rarely in the native state. + +Besides being found with circumstances thus corresponding to the natural +facility, or to the impediments attending the metallization of those +different calces, the native metals are also found in such a shape, and +with such marks, as can only agree with the fusion of those bodies; +that is to say, those appearances are perfectly irreconcilable with any +manner of solution and precipitation. + +For the truth of this assertion, among a thousand other examples, I +appeal to that famous mass of native iron discovered by Mr Pallas in +Siberia. This mass being so well known to all the mineralists of Europe, +any comment upon its shape and structure will be unnecessary[8]. + +[Note 8: Since this Dissertation was written, M. de la Peyrouse has +discovered a native manganese. The circumstances of this mineral are so +well adapted for illustrating the present doctrine, and so well related +by M. de la Peyrouse, that I should be wanting to the interest of +mineral knowledge, were I not to give here that part of his Memoir. + +"Lorsque je fis inserer dans le journal de physique de l'annee 1780, au +mois de Janvier, une Dissertation contenant la classification des mines +de manganese, je ne connoissois point, a cette epoque, la mine de +manganese native. Elle a la couleur de son regule: Elle salit les doigts +de la meme teinte. Son tissu parait aussi lamelleux, et les lames +semblent affecter une sorte de divergence. Elle a ainsi que lui, l'eclat +metallique; comme lui elle se laisse aplatir sous le marteau, et +s'exfolie si l'on redouble les coups; mais une circonstance qui est trop +frappante pour que je l'omette, c'est la figure de la manganese native, +si prodigieusement conforme a celle du regule, qu'on s'y laisseroit +tromper, si la mine n'etoit encore dans sa gangue: Figure +tres-essentielle a observer ici, parce qu'elle est due a la nature meme +de la manganese. En effet, pour reduire toutes les mines en general, il +faut employer divers flux appropries. Pour la reduction de la manganese, +bien loin d'user de ce moyen, il faut, au contraire, eloigner tout flux, +produire la fusion, par la seule violence et la promptitude du feu. Et +telle est la propension naturelle et prodigieuse de la manganese a la +vitrification, qu'on n'a pu parvenir encore a reduire son regule en un +seul culot; on trouve dans le creuset plusieurs petits boutons, qui +forment autant de culots separes. Dans la mine de manganese native, elle +n'est point en une seule masse; elle est disposee egalement en plusieurs +culots separes, et un peu aplatis, comme ceux que l'art produit; +beaucoup plus gros, a la verite, parce que les agens de la nature +doivent avoir une autre energie, que ceux de nos laboratoires; et cette +ressemblance si exacte, semble devoir vous faire penser que la mine +native a ete produite par le feu, tout comme son regule. La presence +de la chaux argentee de la manganese, me permettroit de croire que la +nature n'a fait que reduire cette chaux. Du reste, cette mine native +est tres-pure, et ne contient aucune partie attirable a l'aimant. Cette +mine, unique jusqu'a ce moment, vient, tout comme les autres manganese +que j'ai decrites, des mines de fer de _Sem_, dans la vallee de +_Viedersos_, en Comte de Foix."--_Journal de Physique, Janvier 1786_.] + +We come now to the _second_ species of inflammable bodies called oily or +bituminous. These substances are also found variously mixed with mineral +bodies, as well as forming strata of themselves; they are, therefore, a +proper subject for a particular examination. + +In the process of vegetation, there are produced oily and resinous +substances; and, from the collection of these substances at the bottom +of the ocean, there are formed strata, which have afterwards undergone +various degrees of beat, and have been variously changed, in consequence +of the effects of that heat, according as the distillation of the more +volatile parts of those bodies has been suffered to proceed. + +In order to understand this, it must be considered, that, while immersed +in water, and under insuperable compression, the vegetable, oily, and +resinous substances, would appear to be unalterable by heat; and it is +only in proportion as certain chemical separations take place, that +these inflammable bodies are changed in their substance by the +application of heat. Now, the most general change of this kind is in +consequence of evaporation, or the distillation of their more volatile +parts, by which oily substances become bituminous, and bituminous +substances become coaly. + +There is here a gradation which may be best understood, by comparing the +extremes. + +On the one hand, we know by experiment, that oily and bituminous +substances can be melted and partly changed into vapour by heat, and +that they become harder and denser, in proportion as the more volatile +parts have evaporated from them. On the other hand, coaly substances are +destitute of fusibility and volatility, in proportion as they have +been exposed to greater degrees of heat, and to other circumstances +favourable to the dissipation of their more volatile and fluid parts. + +If, therefore, in mineral bodies, we find the two extreme states of this +combustible substance, and also the intermediate states, we must either +conclude, that this particular operation of heat has been thus actually +employed in nature, or we must explain those appearances by some other +means, in as satisfactory a manner, and so as shall be consistent with +other appearances. + +In this case, it will avail nothing to have recourse to the false +analogy of water dissolving and crystallising salts, which has been so +much employed for the explanation of other mineral appearances. The +operation here in question is of a different nature, and necessarily +requires both the powers of heat and proper conditions for evaporation. + +Therefore, in order to decide the point, with regard to what is the +power in nature by which mineral bodies have become solid, we have +but to find bituminous substance in the most complete state of coal, +intimately connected with some other substance, which is more generally +found consolidating the strata, and assisting in the concretion of +mineral substances. But I have in my possession the most undoubted proof +of this kind. It is a mineral vein, or cavity, in which are blended +together coal of the most fixed kind, quartz and marmor metallicum. Nor +is this all; for the specimen now referred to is contained in a rock +of this kind, which every naturalist now-a-days will allow to have +congealed from a fluid state of fusion. I have also similar specimens +from the same place, in which the coal is not of that fixed and +infusible kind which burns without flame or smoke, but is bituminous or +inflammable coal. + +We have hitherto been resting the argument upon a single point, for the +sake of simplicity or clearness, not for want of those circumstances +which shall be found to corroborate the theory. The strata of fossil +coal are found in almost every intermediate state, as well as in those +of bitumen and charcoal. Of the one kind is that fossil coal which melts +or becomes fluid upon receiving heat; of the other, is that species of +coal, found both in Wales and Scotland, which is perfectly infusible in +the fire, and burns like coals, without flame or smoke. The one species +abounds in oily matter, the other has been distilled by heat, until it +has become a _caput mortuum_, or perfect coal. + +The more volatile parts of these bituminous bodies are found in their +separate state on some occasions. There is a stratum of limestone in +Fifeshire, near Raith, which, though but slightly tinged with a black +colour, contains bituminous matter, like pitch, in many cavities, which +are lined with calcareous spar crystallised. I have a specimen of such +a cavity, in which the bitumen is in sphericles, or rounded drops, +immersed in the calcareous spar. + +Now, it is to be observed, that, if the cavity in the solid limestone or +marble, which is lined with calcareous crystals containing pyrites, had +been thus encrusted by means of the filtration of water, this water must +have dissolved calcareous spar, pyrites, and bitumen. But these natural +appearances would not even be explained by this dissolution and supposed +filtration of those substances. There is also required, _first_, A +cause for the separation of those different substances from the aqueous +menstruum in which they had been dissolved; _2dly_, An explanation of +the way in which a dissolved bitumen should be formed into round hard +bodies of the most solid structure; and, _lastly_, Some probable means +for this complicated operation being performed, below the bottom of the +ocean, in the close cavity of a marble stratum. + +Thus, the additional proof, from the facts relating to the bituminous +substances, conspiring with that from the phenomena of other bodies, +affords the strongest corroboration of this opinion, that the various +concretions found in the internal parts of strata have not been +occasioned by means of aqueous solution, but by the power of heat and +operation of simple fusion, preparing those different substances to +concrete and crystallise in cooling. + +The arguments which have been now employed for proving that strata have +been consolidated by the power of heat, or by the means of fusion, have +been drawn chiefly from the insoluble nature of those consolidating +substances in relation to water, which is the only general menstruum +that can be allowed for the mineral regions. But there are found, in +the mineral kingdom, many solid masses of saltgem, which is a soluble +substance. It may be now inquired, How far these masses, which are not +infrequent in the earth, tend either to confirm the present theory, or, +on the contrary, to give countenance to that which supposes water the +chief instrument in consolidating strata. + +The formation of salt at the bottom of the sea, without the assistance +of subterranean fire, is not a thing unsupposable, as at first sight +it might appear. Let us but suppose a rock placed across the gut +of Gibraltar, (a case nowise unnatural), and the bottom of the +Mediterranean would be certainly filled with salt, because the +evaporation from the surface of that sea exceeds the measure of its +supply. + +But strata of salt, formed in this manner at the bottom of the sea, are +as far from being consolidated by means of aqueous solution, as a bed of +sand in the same situation; and we cannot explain the consolidation of +such a stratum of salt by means of water, without supposing subterranean +heat employed, to evaporate the brine which would successively occupy +the interstices of the saline crystals. But this, it may be observed, is +equally departing from the natural operation of water, as the means for +consolidating the sediment of the ocean, as if we were to suppose +the same thing done by heat and fusion. For the question is not, +If subterranean heat be of sufficient intensity for the purpose of +consolidating strata by the fusion of their substances; the question is, +Whether it be by means of this agent, subterranean heat, or by water +alone, without the operation of a melting heat, that those materials +have been variously consolidated. + +The example now under consideration, consolidated mineral salt, will +serve to throw some light upon the subject; for, as it is to be shown, +that this body of salt had been consolidated by perfect fusion, and +not by means of aqueous solution, the consolidation of strata of +indissoluble substances, by the operation of a melting heat, will meet +with all that confirmation which the consistency of natural appearances +can give. + +The salt rock in Cheshire lies in strata of red marl. It is horizontal +in its direction. I do not know its thickness, but it is dug thirty or +forty feet deep. The body of this rock is perfectly solid, and the salt, +in many places, pure, colourless, and transparent, breaking with a +sparry cubical structure. But the greatest part is tinged by the +admixture of the marl, and that in various degrees, from the slightest +tinge of red, to the most perfect opacity. Thus, the rock appears as if +it had been a mass of fluid salt, in which had been floating a quantity +of marly substance, not uniformly mixed, but every where separating and +subsiding from the pure saline substance. + +There is also to be observed a certain regularity in this separation of +the tinging from the colourless substance, which, at a proper distance, +gives to the perpendicular section of the rock a distinguishable figure +in its structure. When looking at this appearance near the bottom of +the rock, it, at first, presented me with the figure of regular +stratification; but, upon examining the whole mass of rock, I found, +that it was only towards the bottom that this stratified appearance took +place; and that, at the top of the rock, the most beautiful and regular +figure was to be observed; but a figure the most opposite to that of +stratification. It was all composed of concentric circles; and these +appeared to be the section of a mass, composed altogether of concentric +spheres, like those beautiful systems of configuration which agates so +frequently present us with in miniature. In about eight or ten feet from +the top, the circles growing large, were blended together, and gradually +lost their regular appearance, until, at a greater depth, they again +appeared in resemblance of a stratification. + +This regular arrangement of the floating marly substance in the body +of salt, which is that of the structure of a coated pebble, or that +of concentric spheres, is altogether inexplicable upon any other +supposition, than the perfect fluidity or fusion of the salt, and the +attractions and repulsions of the contained substances. It is in vain +to look, in the operations of solution and evaporation, for that which +nothing but perfect fluidity or fusion can explain. + +This example of a mineral salt congealed from a melted state, may be +confirmed from another which I have from Dr Black, who suggested it to +me. It is an alkaline salt, found in a mineral state, and described in +the Philosophical Transactions, _anno_ 1771. But to understand this +specimen, something must be premised with regard to the nature of fossil +alkali. + +The fossil alkali crystallises from a dissolved state, in combining +itself with a large portion of the water, in the manner of alum; and, +in this case, the water is essential to the constitution of that +transparent crystalline body; for, upon the evaporation of the water, +the transparent salt loses its solidity, and becomes a white powder. If, +instead of being gently dried, the crystalline salt is suddenly exposed +to a sufficient degree of heat, that is, somewhat more than boiling +water, it enters into the state of aqueous fusion, and it boils, in +emitting the water by means of which it had been crystallised in the +cold, and rendered fluid in that heated state. It is not possible to +crystallise this alkaline salt from a dissolved state, without the +combination of that quantity of water, nor to separate that water +without destroying its crystalline state. + +But in this mineral specimen, we have a solid crystalline salt, with +a structure which, upon fracture, appears to be sparry and radiated, +something resembling that of zeolite. It contains no water in its +crystallization, but melts in a sufficient heat, without any aqueous +fusion. Therefore, this salt must have been in a fluid state of fusion, +immediately before its congelation and crystallization. + +It would be endless to give examples of particular facts, so many are +the different natural appearances that occur, attended with a variety of +different circumstances. + +There is one, however, which is peculiarly distinct, admits of +sufficiently accurate description, and contains circumstances from which +conclusions may be drawn with clearness. This is the ironstone, which +is commonly found among the argillaceous strata, attendant upon fossil +coal, both in Scotland and in England. + +This stone is generally found among the bituminous schistus, or black +argillaceous strata, either in separate masses of various shapes and +sizes, or forming of itself strata which are more or less continuous in +their direction among the schistous or argillaceous beds. + +This mineral contains, in general, from 40 to 50 _per cent._ of iron, +and it loses near one third of its weight in calcination. Before +calcination it is of a grey colour, is not penetrable by water, and +takes a polish. In this state, therefore, it is perfectly solid; but +being calcined, it becomes red, porous, and tender. + +The fact to be proved with regard to these iron-stones is this, That +they have acquired their solid state from fusion, and not in concreting +from any aqueous solution. + +To abridge this disquisition, no argument is to be taken from contingent +circumstances, (which, however, are often found here as well as in the +case of marbles); such only are to be employed as are general to the +subject, and arise necessarily from the nature of the operation. + +It will be proper to describe a species of these stones, which is +remarkably regular in its form. It is that found at Aberlady, in East +Lothian. + +The form of these iron-stones is that of an oblate or much compressed +sphere, and the size from two or three inches diameter to more than +a foot. In the circular or horizontal section, they present the most +elegant septarium[9]; and, from the examination of this particular +structure, the following conclusions may be drawn. + +_First_, That, the septa have been formed by the uniform contraction +of the internal parts of the stone, the volume of the central parts +diminishing more than that of the circumference; by this means, the +separations of the stone diminish, in a progression from the center +towards the circumference. + +_2d_, That there are only two ways in which the septa must have received +the spar or spatthose ore with which they are filled, more or less, +either, _first_ By insinuation into the cavity of the septa after these +were formed; or, _2dly_, By separation from the substance of the stone, +at the same time that the septa were forming. + +[Note 9: Plate I.] + +Were the first supposition true, appearances would be observable, +showing that the sparry substance had been admitted, either through the +porous structure of the stone, or through proper apertures communicating +from without. Now, if either one or other of these had been the case, +and that the stone had been consolidated from no other cause than +concretion from a dissolved state, that particular structure of the +stone, by means of which the spar had been admitted, must appear at +present upon an accurate examination. + +This, however, is not the case, and we may rest the argument here. The +septa reach not the circumference; the surface of the stone is solid and +uniform in every part; and there is not any appearance of the spar in +the argillaceous bed around the stone. + +It, therefore, necessarily follows, that the contraction of the +iron-stone, in order to form septa, and the filling of these cavities +with spar, had proceeded _pari passu_; and that this operation must have +been brought about by means of fusion, or by congelation from a state of +simple fluidity and expansion. + +It is only further to be observed, that all the arguments which have +been already employed, concerning mineral concretions from a simply +fluid state, or that of fusion, here take place. I have septaria of this +kind, in which, besides pyrites, iron-ore, calcareous spar, and another +that is ferruginous and compound, there is contained siliceous +crystals; a case which is not so common. I have them also attended with +circumstances of concretion and crystallization, which, besides being +extremely rare, are equally curious and interesting. + +There is one fact more which is well worth our attention, being one +of those which are so general in the mineral regions. It is the +crystallizations which are found in close cavities of the most solid +bodies. + +Nothing is more common than this appearance. Cavities are every where +found closely lined with crystallizations, of every different substance +which may be supposed in those places. These concretions are well known +to naturalists, and form part of the beautiful specimens which +are preserved in the cabinets of collectors, and which the German +mineralists have termed _Drusen_. I shall only particularise one +species, which may be described upon principle, and therefore may be +a proper subject on which to reason, for ascertaining the order of +production in certain bodies. This body, which we are now to examine, is +of the agate species. + +We have now been considering the means employed by nature in +consolidating strata which were originally of an open structure; but in +perfectly solid strata we find bodies of agate, which have evidently +been formed in that place where they now are found. This fact, however, +is not still that of which we are now particularly to inquire; for this, +of which we are to treat, concerns only a cavity within this agate; now, +whatever may have been the origin of the agate itself, we are to show, +from what appears within its cavity, that the crystallizations which are +found in this place had arisen from a simply fluid state, and not from +that of any manner of solution. + +The agates now in question are those of the coated kind, so frequent in +this country, called pebbles. Many of these are filled with a siliceous +crystallization, which evidently proceeds from the circumference +towards the centre. Many of them, again, are hollow. Those cavities are +variously lined with crystallized substances; and these are the object +of the present examination. + +But before describing what is found within, it is necessary to attend to +this particular circumstance, that the cavity is perfectly inclosed with +many solid coats, impervious to air or water, but particularly with +the external cortical part, which is extremely hard, takes the highest +polish, and is of the most perfect solidity, admitting the passage of +nothing but light and heat. + +Within these cavities, we find, _1st_, The coat of crystals with which +this cavity is always lined; and this is general to all substances +concreting, in similar circumstances, from a state of fusion; for when +thus at liberty they naturally crystallise. _2dly_, We have frequently +a subsequent crystallization, resting on the first, and more or less +immersed in it. _3dly_, There is also sometimes a third crystallization, +superincumbent on the second, in like manner as the second was on the +first. I shall mention some particulars. + +I have one specimen, in which the primary crystals are siliceous, the +secondary thin foliaceous crystals of deep red but transparent iron-ore, +forming elegant figures, that have the form of roses. The tertiary +crystallization is a frosting of small siliceous crystals upon the edges +of the foliaceous crystals. + +In other specimens, there is first a lining of colourless siliceous +crystals, then another lining of amethystine crystals, and sometimes +within that, fuliginous crystals. Upon these fuliginous and amethystine +crystals are many sphericles or hemispheres of red compact iron-ore, +like haematites. + +In others, again, the primary crystals are siliceous, and the secondary +calcareous. Of this kind, I have one which has, upon the calcareous +crystals, beautiful transparent siliceous crystals, and iron sphericles +both upon all these crystals, and within them. + +_Lastly_, I have an agate formed of various red and white coats, and +beautifully figured. The cavity within the coated part of the pebble is +filled up without vacuity, first, with colourless siliceous crystals; +secondly, with fuliginous crystals; and, lastly, with white or +colourless calcareous spar. But between the spar and crystals there are +many sphericles, seemingly of iron, half sunk into each of these two +different substances. + +From these facts, I may now be allowed to draw the following +conclusions: + +1_st_, That concretion had proceeded from the surface of the agate body +inwards. This necessarily follows from the nature of those figured +bodies, the figures of the external coats always determining the shape +of those within, and never, contrarily, those within affecting those +without. + +2_dly_, That when the agate was formed, the cavity then contained every +thing which now is found within it, and nothing more. + +3_dly_, That the contained substances must have been in a fluid state, +in order to their crystallizing. + +_Lastly_, That as this fluid state had not been the effect of solution +in a menstruum, it must have been fluidity from heat and fusion. + +Let us now make one general observation and argument with regard to +the formation of those various coated, concreted, crystallized, and +configured bodies. Were the crystallization and configuration found +to proceed from a central body, and to be directed from that centre +outwards, then, without inquiring into collateral appearances, and other +proofs with regard to the natural concretion of those substances, we +might suppose that these concretions might have proceeded from that +central body gradually by accretion, and that the concreting and +crystallizing substances might have been supplied from a fluid which had +before retained the concreting substance in solution; in like manner as +the crystallizations of sugar, which are formed in the solution of +that saccharine substance, and are termed candies, are formed upon the +threads which are extended in the crystallizing vessel for that purpose. +But if, on the contrary, we are to consider those mineral bodies as +spheres of alternate coats, composed of agate, crystal, spars, etc.; and +if all those crystallizations have their _bases_ upon the uncrystallized +coat which is immediately external to it, and their _apices_ turned +inwards into the next internal solid coat, it is not possible to +conceive that a structure of this kind could have been formed in +any manner from a solution. But this last manner is the way without +exception in which those mineral bodies are found; therefore we are to +conclude, that the concretion of those bodies had proceeded immediately +from a state of fusion or simple fluidity. + +In granite these cavities are commonly lined with the crystal +corresponding to the constituent substances of the stone, viz. quartz, +feld-spar, and mica or talk. M. de Saussure, (Voyages dans les Alpes, +tom. ii. sec. 722.), says, "On trouve frequemment des amas considerables +de spath calcaire, crystallise dans les grottes ou se forme le crystal de +roche; quoique ces grottes soient renfermees dans le coeur des montagnes +d'un granit vif, & qu'on ne voie aucun roc calcaire au dessus de ces +montagnes." + +So accurate an observer, and so complete a naturalist, must have +observed how the extraneous substance had been introduced into this +cavity, had they not been formed together the cavity and the calcareous +crystals. That M. de Saussure perceived no means for that introduction, +will appear from what immediately follows in that paragraph. "Ces rocs +auroient-ils ete detruits, ou bien ce spath n'est il que le produit +d'une secretion des parties calcaires que l'on fait etres dispersees +entre les divers elemens du granit?" + +Had M. de Saussure allowed himself to suppose all those substances in +fusion, of which there cannot be a doubt, he would soon have resolved +both this difficulty, and also that of finding molybdena crystallized +along with feld-spar, in a cavity of this kind. sec. 718. + +To this argument, taken from the close cavities in our agates, I am now +to add another demonstration. It is the case of the calcedony agate, +containing a body of calcareous spar; here it is to be shown, that, +while the calcareous body was altogether inclosed within the calcedony +nodular body, these two substances had been perfectly soft, and had +mutually affected each others shape, in concreting from a fluid state. +In order to see this, we are to consider that both those substances have +specific shapes in which they concrete from the third state; the +sparry structure of the one is well known; the spherical or mammelated +crystallization of the calcedony, is no less conspicuous; this last +is, in the present case, spherical figures, which are some of +them hemispheres, or even more. The figures which we have now in +contemplation are so distinctly different as cannot be mistaken; the +one is a rhombic figure bounded by planes; the other is a most perfect +spherical form; and both these are specific figures, belonging +respectively to the crystallization of those two substances. + +The argument now to be employed for proving that those two bodies had +concreted from the fluid state of fusion, and not from any manner of +solution, is this: That, were the one of those bodies to be found +impressing the other with its specific figure, we must conclude that the +impressing body had concreted or crystallized while the impressed body +was in a soft or fluid state; and that, if they are both found mutually +impressing and impressed by each other, they must have both been in +the fluid and concreting state together. Now the fact is, that the +calcareous body is perfectly inclosed within the solid calcedony, and +that they are mutually impressed by each others specific figure, the +sparry structure of the calcareous body impressing the calcedony with +its type of planes and angles, at the same time that, in other parts, +the spherical figures of the calcedony enter the solid body of the +spar, and thus impress their mammelated figures into that part which is +contiguous. It is therefore inconceivable, that these appearances +could have been produced in any other manner than by those two bodies +concreting from a simply fluid state. + +There are in jaspers and agates many other appearances, from whence the +fusion of those substances may be concluded with great certainty and +precision; but it is hoped, that what has been now given may suffice for +establishing that proposition without any doubt. + +It must not be here objected, That there are frequently found siliceous +crystals and amethysts containing water; and that it is impossible +to confine water even in melted glass. It is true, that here, at the +surface of the earth, melted glass cannot, in ordinary circumstances, be +made to receive and inclose condensed water; but let us only suppose a +sufficient degree of compression in the body of melted glass, and we +can easily imagine it to receive and confine water as well as any +other substance. But if, even in our operations, water, by means of +compression, may be made to endure the heat of red hot iron without +being converted into vapour, what may not the power of nature be able to +perform? The place of mineral operations is not on the surface of the +earth; and we are not to limit nature with our imbecility, or estimate +the powers of nature by the measure of our own.[10] + +[Note 10: This is so material a principle in the theory of consolidating +the strata of the earth by the fusion of mineral substances, that I beg +the particular attention of the reader to that subject. The effect of +compression upon compound substances, submitted to increased degrees of +heat, is not a matter of supposition, it is an established principle +in natural philosophy. This, like every other physical principle, is +founded upon matter of fact or experience; we find, that many compound +substances may with heat be easily changed, by having their more +volatile parts separated when under a small compression; but these +substances are preserved without change when sufficiently compressed. +Our experiments of this kind are necessarily extremely limited; they +are not, however, for that reason, the less conclusive. The effects of +increasing degrees of heat are certainly prevented by increasing degrees +of compression; but the rate at which the different effects of those +powers proceed, or the measure of those different degrees of increase +that may be made without changing the constitution of the compound +substance, are not known; nor is there any limit to be set to that +operation, so far as we know. Consequently, it is a physical principle, +That the evaporation of volatile substances by heat, or the reparation +of them from a compound substance, consequently the effect of fire in +changing that compound substance, may be absolutely prevented by means +of compression. + +It now remains to be considered, how far there is reason to conclude +that there had been sufficient degrees of compression in the mineral +regions, for the purpose of melting the various substances with which we +find strata consolidated, without changing the chemical constitution of +those compound substances. + +Had I, in reasoning _a priori_, asserted, That all mineral bodies might +have been melted without change, when under sufficient compression, +there might have arisen, in the minds of reasoning men, some doubt with +regard to the certainty of that proposition, however probable it were to +be esteemed: But when, in reasoning _a posteriori_, it is found that all +mineral bodies have been actually melted, then, all that is required to +establish the proposition on which I have founded my theory, is to +see that there must have been immense degrees of compression upon the +subjects in question; for we neither know the degree of heat which had +been employed, nor that of compression by which the effect of the heat +must have been modified. + +Now, in order to see that there had been immense compression, we have +but to consider that the formation of the strata, which are to be +consolidated, was at the bottom of the ocean, and that this place is to +us unfathomable. If it be farther necessary to show that it had been at +such unfathomable depth strata were consolidated, it will be sufficient +to observe, it is not upon the surface of the earth, or above the level +of the sea, that this mineral operation can take place; for, it is there +that those consolidated bodies are redissolved, or necessarily going +into decay, which is the opposite to that operation which we are now +inquiring after; therefore, if they were consolidated in any other place +than at the bottom of the sea, it must have been between that place of +their formation and the surface of the sea; but that is a supposition +which we have not any reason to make; therefore, we must conclude that +it was at the bottom of the ocean those stratified bodies had been +consolidated.] + +To conclude this long chemico-mineral disquisition, I have specimens in +which the mixture of calcareous, siliceous, and metallic substances, +in almost every species of concretion which is to be found in mineral +bodies, may be observed, and in which there is exhibited, in miniature, +almost every species of mineral transaction, which, in nature, is found +upon a scale of grandeur and magnificence. They are nodules contained in +the whin-stone, porphyry, or basaltes of the Calton-hill, by Edinburgh; +a body which is to be afterwards examined, when it will be found to have +flowed, and to have been in fusion, by the operation of subterraneous +heat. + +This evidence, though most conclusive with regard to the application of +subterraneous heat, as the means employed in bringing into fusion all +the different substances with which strata may be found consolidated, is +not directly a proof that strata had been consolidated by the fusion of +their proper substance. It was necessary to see the general nature of +the evidence, for the universal application of subterraneous heat, in +the fusion of every kind of mineral body. Now, that this has been done, +we may give examples of strata consolidated without the introduction +of foreign matter, merely by the softening or fusion of their own +materials. + +For this purpose, we may consider two different species of strata, +such as are perfectly simple in their nature, of the most distinct +substances, and whose origin is perfectly understood, consequently, +whose subsequent changes may be reasoned upon with certainty and +clearness. These are the siliceous and calcareous strata; and these +are the two prevailing substances of the globe, all the rest being, in +comparison of these, as nothing; for unless it be the bituminous or coal +strata, there is hardly any other which does not necessarily contain +more or less of one or other of these two substances. If, therefore, +it can be shown, that both of those two general strata have been +consolidated by the simple fusion of their substance, no _desideratum_ +or doubt will remain, with regard to the nature of that operation which +has been transacted at great depths of the earth, places to which all +access is denied to mortal eyes. + +We are now to prove, _first_, That those strata have been consolidated +by simple fusion; and, _2dly_, That this operation is universal, in +relation to the strata of the earth, as having produced the various +degrees of solidity or hardness in these bodies. + +I shall first remark, that a fortuitous collection of hard bodies, such +as gravel and sand, can only touch in points, and cannot, while in that +hard state, be made to correspond so precisely to each others shape as +to consolidate the mass. But if these hard bodies should be softened in +their substance, or brought into a certain degree of fusion, they +might be adapted mutually to each other, and thus consolidate the open +structure of the mass. Therefore, to prove the present point, we have +but to exhibit specimens of siliceous and calcareous strata which have +been evidently consolidated in this manner. + +Of the first kind, great varieties occur in this country. It is, +therefore, needless to describe these particularly. They are the +consolidated strata of gravel and sand, often containing abundance of +feld-spar, and thus graduating into granite; a body, in this respect, +perfectly similar to the more regular strata which we now examine. + +The second kind, again, are not so common in this country, unless +we consider the shells and coralline bodies in our lime-stones, as +exhibiting the same example, which indeed they do. But I have a specimen +of marble from Spain, which may be described, and which will afford the +most satisfactory evidence of the fact in question. + +This Spanish marble may be considered as a species of pudding-stone, +being formed of calcareous gravel; a species of marble which, from Mr +Bowles' Natural History, appears to be very common in Spain. The gravel +of which this marble is composed, consists of fragments of other marbles +of different kinds. Among these, are different species of _oolites_ +marble, some shell marbles, and some composed of a chalky substance, or +of undistinguishable parts. But it appears, that all these different +marbles had been consolidated or made hard, then broken into fragments, +rolled and worn by attrition, and thus collected together, along with +some sand or small siliceous bodies, into one mass. Lastly, This +compound body is consolidated in such a manner as to give the most +distinct evidence, that this had been executed by the operation of heat +or simple fusion. + +The proof I give is this, That besides the general conformation of those +hard bodies, so as to be perfectly adapted to each other's shape, there +is, in some places, a mutual indentation of the different pieces of +gravel into each other; an indentation which resembles perfectly that +junction of the different bones of the _cranium_, called sutures, and +which must have necessarily required a mixture of those bodies while in +a soft or fluid state. + +This appearance of indentation is by no means singular, or limited to +one particular specimen. I have several specimens of different marbles, +in which fine examples of this species of mixture may be perceived. But +in this particular case of the Spanish pudding-stone, where the mutual +indentation is made between two pieces of hard stone, worn round by +attrition, the softening or fusion of these two bodies is not simply +rendered probable, but demonstrated. + +Having thus proved, that those strata had been consolidated by simple +fusion, as proposed, we now proceed to show, that this mineral operation +had been not only general, as being found in all the regions of the +globe, but universal, in consolidating our earth in all the various +degrees, from loose and incoherent shells and sand, to the most solid +bodies of the siliceous and calcareous substances. + +To exemplify this in the various collections and mixtures of sands, +gravels, shells, and corals, were endless and superfluous. I shall only +take, for an example, one simple homogeneous body, in order to exhibit +it in the various degrees of consolidation, from the state of simple +incoherent earth to that of the most solid marble. It must be evident +that this is chalk; naturally a soft calcareous earth, but which may be +also found consolidated in every different degree. + +Through the middle of the Isle of Wight, there runs a ridge of hills of +indurated chalk. This ridge runs from the Isle of Wight directly west +into Dorsetshire, and goes by Corscastle towards Dorchester, perhaps +beyond that place. The sea has broke through this ridge at the west +end of the Isle of Wight, where columns of the indurated chalk remain, +called the Needles; the same appearance being found upon the opposite +shore in Dorsetshire. + +In this field of chalk, we find every gradation of that soft earthy +substance to the most consolidated body of this indurated ridge, which +is not solid marble, but which has lost its chalky property, and has +acquired a kind of stony hardness. + +We want only further to see this cretaceous substance in its most +indurated and consolidated state; and this we have in the north of +Ireland, not far from the Giants Causeway. I have examined cargoes of +this lime-stone brought to the west of Scotland, and find the most +perfect evidence of this body having been once a mass of chalk, which is +now a solid marble. + +Thus, if it is by means of fusion that the strata of the earth have +been, in many places, consolidated, we must conclude, that all the +degrees of consolidation, which are indefinite, have been brought about +by the same means. + +Now, that all the strata of the mineral regions, which are those only +now examined, have been consolidated in some degree, is a fact for which +no proof can be offered here, but must be submitted to experience and +inquiry; so far, however, as they shall be considered as consolidated in +any degree, which they certainly are in general, we have investigated +the means which had been employed in that mineral operation. + +We have now considered the concretions of particular bodies, and the +general consolidation of strata; but it may be alleged, that there is +a great part of the solid mass of this earth not properly comprehended +among those bodies which have been thus proved to be consolidated by +means of fusion. The body here alluded to is granite; a mass which is +not generally stratified, and which, being a body perfectly solid, +and forming some part in the structure of this earth, deserves to be +considered. + +The nature of granite, as a part of the structure of the earth, is too +intricate a subject to be here considered, where we only seek to prove +the fusion of a substance from the evident marks which are to be +observed in a body. We shall, therefore, only now consider one +particular species of granite; and if this shall appear to have been in +a fluid state of fusion, we may be allowed to extend this property to +all the kind. + +The species now to be examined comes from the north country, about four +or five miles west from Portfoy, on the road to Huntly. I have not been +upon the spot, but am informed that this rock is immediately connected +or continuous with the common granite of the country. This indeed +appears in the specimens which I have got; for, in some of these, there +is to be perceived a gradation from the regular to the irregular sort. + +This rock may indeed be considered, in some respects, as a porphyry; for +it has an evident ground, which is feld-spar, in its sparry state; +and it is, in one view, distinctly maculated with quartz, which is +transparent, but somewhat dark-coloured[11]. + +[Note 11: Plate II. fig. 1. 2. 3.] + +Considered as a porphyry, this specimen is no less singular than as a +granite. For, instead of a siliceous ground, maculated with the rhombic +feld-spar, which is the common state of porphyry, the ground is +uniformly crystallised, or a homogeneous regular feld-spar, maculated +with the transparent siliceous substance. But as, besides the feld-spar +and quartz, which are the constituent parts of the stone, there is also +mica, in some places, it may, with propriety, be termed a granite. + +The singularity of this specimen consists, not in the nature or +proportions of its constituent parts, but in the uniformity of the +sparry ground, and the regular shape of the quartz mixture. This +siliceous substance, viewed in one direction, or longitudinally, may +be considered as columnar, prismatical, or continued in lines running +nearly parallel. These columnar bodies of quartz are beautifully +impressed with a figure on the sides, where they are in contact with the +spar. This figure is that of furrows or channels, which are perfectly +parallel, and run across the longitudinal direction of the quartz. This +is represented in fig. 4. This striated figure is only seen when, by +fracture, the quartz is separated from the contiguous spar. + +But what I would here more particularly represent is, the transverse +section of those longitudinal siliceous bodies These are seen in fig. 1. +2. and 3. They have not only separately the forms of certain typographic +characters, but collectively give the regular lineal appearance of types +set in writing. + +It is evident from the inspection of this fossil, that the sparry and +siliceous substances had been mixed together in a fluid state; and that +the crystallization of the sparry substance, which is rhombic, had +determined the regular structure of the quartz, at least in some +directions. + +Thus, the siliceous substance is to be considered as included in the +spar, and as figured, according to the laws of crystallization proper +to the sparry ground; but the spar is also to be found included in the +quartz. It is not, indeed, always perfectly included or inclosed on all +sides; but this is sometimes the case, or it appears so in the section. +Fig. 5. 6. 7. 8. 9. and 10. are those cases magnified, and represent the +different figured quartz inclosing the feld-spar. In one of them, the +feld-spar, which is contained within the quartz, contains also a small +triangle of quartz, which it incloses. Now, it is not possible to +conceive any other way in which those two substances, quartz and +feld-spar, could be thus concreted, except by congelation from a fluid +state, in which they had been mixed. + +There is one thing more to be observed with regard to this curious +species of granite. It is the different order or arrangement of the +crystallization or internal structure of the feld-spar ground, in two +contiguous parts of the same mass. This is to be perceived in the +polished surface of the stone, by means of the reflection of light. + +There is a certain direction in which, viewing the stone, when the light +falls with a proper obliquity, we see a luminous reflection from the +internal parts of the stone. This arises from the reflecting surfaces +of the sparry structure or minute cracks, all turned in one direction, +consequently, giving that luminous appearance only in one point of view. + +Now, all the parts of the stone in which the figured quartz is directed +in the same manner, or regularly placed in relation to each other, +present that shining appearance to the eye at one time, or in the same +point of direction. But there are parts of the mass, which, though +immediately contiguous and properly continuous, have a different +disposition of the figured quartz; and these two distinguished masses, +in the same surface of the polished stone, give to the eye their shining +appearance in very different directions. Fig. 3. shows two of those +figured and shining masses, in the same plane or polished surface. + +It must be evident, that, as the crystallization of the sparry structure +is the figuring cause of the quartz bodies, there must be observed a +certain correspondency between those two things, the alinement (if I may +be allowed the expression) of the quartz, and the shining of the sparry +ground. It must also appear, that at the time of congelation of the +fluid spar, those two contiguous portions had been differently disposed +in the crystallization of their substance. This is an observation which +I have had frequent opportunities of making, with respect to masses of +calcareous spar. + +Upon the whole, therefore, whether we shall consider granite as a +stratum or as an irregular mass, whether as a collection of several +materials, or as the separation of substances which had been mixed, +there is sufficient evidence of this body having been consolidated by +means of fusion, and in no other manner. + +We are thus led to suppose, that the power of heat and operation +of fusion must have been employed in consolidating strata of loose +materials, which had been collected together and amassed at the bottom +of the ocean. It will, therefore, be proper to consider, what are the +appearances in consolidated strata that naturally should follow, on the +one hand, from fluidity having been, in this manner, introduced by means +of heat, and, on the other, from the interstices being filled by means +of solution; that so we may compare appearances with the one and other +of those two suppositions, in order to know that with which they may be +only found consistent. + +The consolidation of strata with every different kind of substance was +found to be inconsistent with the supposition, that aqueous solution +had been the means employed for this purpose. This appearance, on the +contrary, is perfectly consistent with the idea, that the fluidity of +these bodies had been the effect of heat; for, whether we suppose the +introduction of foreign matter into the porous mass of a stratum for its +consolidation, or whether we shall suppose the materials of the mass +acquiring a degree of softness, by means of which, together with an +immense compression, the porous body might be rendered solid; the power +of heat, as the cause of fluidity and vapour, is equally proper and +perfectly competent. Here, therefore, appearances are as decidedly in +favour of the last supposition, as they had been inconsistent with the +first. + +But if strata have been consolidated by means of aqueous solution, these +masses should be found precisely in the same state as when they were +originally deposited from the water. The perpendicular section of those +masses might show the compression of the bodies included in them, or of +which they are composed; but the horizontal section could not contain +any separation of the parts of the stratum from one another. + +If, again, strata have been consolidated by means of heat, acting in +such a manner as to soften their substance, then, in cooling, they must +have formed rents or separations of their substance, by the unequal +degrees of contraction which the contiguous strata may have suffered. +Here is a most decisive mark by which the present question must be +determined. + +There is not in nature any appearance more distinct than this of the +perpendicular fissures and separations in strata. These are generally +known to workmen by the terms of veins or backs and cutters; and there +is no consolidated stratum that wants these appearances. Here is, +therefore, a clear decision of the question, Whether it has been by +means of heat, or by means of aqueous solution, that collections of +loose bodies at the bottom of the sea have been consolidated into the +hardest rocks and most perfect marbles[12]. + +[Note 12: This subject is extremely interesting, both to the theory of +the earth, and to the science cf the mining art; I will now illustrate +that theory, with an authority which I received after giving this +dissertation to the Royal Society. It is in the second volume of M. de +Saussure's _voyages dans les Alpes_. Here I find proper examples for +illustrating that subject of mineralogy; and I am happy to have this +opportunity of giving the reasoning of a man of science upon the +subject, and the opinion of a person who is in every respect so well +qualified to judge upon a point of this kind. + +The first example is of a marble in the Alps, (_voyages dans les +Alpes._) tom. 2. page 271. + +"La pate de ces breches est tantot blanche, tantot grise, et les +fragmens qui y font renfermes font, les uns blancs, les autres gris, +d'autres roux, et presque toujours d'une couleur differente de celle de +la pate qui les lit. Ils sont tous de nature calcaire; tels etaient au +moins tous ceux que j'ai pus observer; et ce qu'il-y-a de remarquable, +c'est qu'ils sont tous poses dans le sens des feuillets de la pierre; on +diroit en les voyant, qu'ils ont tous ete comprimes et ecrases dans +le meme sens. Cette meme pierre est melee de mica, sur-tout dans les +interstices des couches et entre les fragmens et la pate qui les reunit; +mais on ne voit point de mica dans les fragmens eux-memes. On trouve +aussi dans ces breches des infiltrations de quartz. Cette pierre est +coupee par des frequentes fissures perpendiculaires aux plans des +couches. On voit clairement que ces fentes out ete formees par l'inegal +affaissement des couches, et non par une retraite spontanee: car les +morceaux ou fragmens etrangers sont tous partages et coupes net par ces +fissures au lieu que dans les divisions naturelles des couches, ces +memes fragmens sont entiers et saillans au dehors de la surface. Les +noeuds de quartz et les divers crystaux, que renferment les roches +feuilletees, presentent le meme phenomene, et l'on peut en tirer la meme +consequence; ils font partages dans les fentes, et entiers dans les +separations des couches." + +He finds those particular strata in the other side of the mountain _col +de la Seigne_, and gives us the following observations: + +"Plus bas on passe entre deux bancs de ces memes breches, entre lesquels +sont interposees des couches d'ardoises noires et de gres feuilletes +micaces, dont la situation est la meme. + +"On retrouve encore ces breches vers le has de la descente, au pied de +pyramides calcaires dont j'ai parle plus haut. Je trouvai en 1774 de +tres-jolis crystaux de roche qui s'etaient formes dans les fentes de +cette breche. Il y avoit meme un melange de quartz et de mica qui +s'etoit moule dans quelques-une de ces fentes. C'etoit donc une roche +semblable aux primitives, et pourtant d'une formation posterieure a +celle de la pierre calcaire. Et quel systeme pourroit nous persuader que +la nature ne puisse encore produire ce qu'elle a produit autrefois!" + +M. de Saussure has here given us an example of a calcareous Braccia, +as he calls it, but which is rather a pudding stone, with veins or +contractions of the mass. He does not seem to understand these as +consequences of the consolidation of those strata; this, however, is +the only light in which these appearances may be explained, when those +bodies are thus divided without any other separation in the mass. + +The second example is found in the vertical strata of those mountains +through which the Rhone has made its way in running from the great +valley of the _Vallais_ towards the lake of Geneva. (Chapitre xlviii.) + +"C'est une espece de petrosilex gris, dur, sonore, un peu transparent, +qui se debite en feuillets minces parfaitement plans et reguliers. Ces +feuillets, ou plutot ces couches, courent a 35 degres du nord par est, +en montant du cote de l'ouest sous un angle de 80 degres. Ces couches +sont coupees par des fentes qui leur sont a-peu-pres perpendiculaires et +qui le sont aussi a l'horizon. Cette pierre s'emploie aux memes usage +que l'ardoise, mais elle est beaucoup plus forte et plus durable, parce +qu'elle est plus dure et moins accessible aux impressions de l'eau et de +l'air. + +Sec. 1047. "Ces petrosilex feuilletes changent peu-a-peu de nature, en +admettant dans les interstices de leurs feuillets des parties de +feldspath. Ils out alors l'apparence d'une roche feuilletee, quartzeuse +et micacee, (_quartzum fornacum W._). Mais cette apparence est +trompeuse; car on n'y trouve pas un atome de quartz: toutes les parties +blanches qui donnent du feu contre l'acier, font du feldspath; et les +parties grise ecailleuses ne font point du mica, ce sont de lames minces +du petrosilex dont j'ai deja parle." + +Here is evidently what I would call petuntze strata, or porcelane stone, +that is, strata formed by the deposits of such materials as might come +from the _detritus_ of granite, arranged at the bottom of the sea, and +consolidated by heat in the mineral regions. We have precisely such +stratified masses in the Pentland hills near Edinburgh. I have also a +specimen of the same kind, brought from the East Indies, in which there +is the print of an organized body. I believe it to be of some coralline +or zoophite. + +Sec. 1048. "Cette roche melangee continue jusqu'a ce que le rocher +s'eloigne un peu du grand chemin. La, ce rocher se presente coupe a +pic dans une grande etendue, et divise par de grandes fentes obliques, +a-peu-pres paralleles entr'elles. Ces fentes partagent la montagne en +grandes tranches de 50 a 60 pieds d'epaisseur, que de loin semblent etre +des couches. Mais lorsqu'on s'en approche, on voit, par le tissu meme +de la pierre feuilletee, que ses vraies couches font avec l'horizon des +angles de 70 a 75 degre, et que ces grandes divisions sont de vraies +fentes par lesquelles un grand nombre de couches consecutives sont +coupees presque perpendiculairement a leurs plans. Les masses de rocher, +comprises entre ces grandes fentes, sont encore divisees par d'autres +fentes plus petites, dont la plupart sont paralleles aux grandes, +d'autres leur sont obliques; mais toutes sont a tres-peu-pres +perpendiculaires aux plans des couches dont la montagne est composee." + +Here is a distinct view of that which may be found to take place in all +consolidated strata, whatever be the composition of the stratum; and +it is this appearance which is here maintained to be a physical +demonstration, that those strata had been consolidated by means of +heat softening their materials. In that case, those stratified +bodies, contracting in cooling, form veins and fissures traversing +perpendicularly their planes; and these veins are afterwards filled with +mineral substances. These are what I have here distinguished as the +_particular_ veins of mineral masses; things perfectly different from +proper mineral or metallic veins, which are more general, as belonging +to immense masses of those strata; and which had been formed, not from +the contraction, but from the disrupture of those masses, and by the +forcible injection of fluid mineral substances from below. Now these two +species of veins, the particular and the general, although occasionally +connected, must be in science carefully distinguished; in the one, we +see the means which had been employed for the consolidation of the +strata; in the other, we see that power by which the strata have been +raised from the bottom of the sea and placed in the atmosphere.] + +Error never can be consistent, nor can truth fail of having support from +the accurate examination of every circumstance. It is not enough to +have found appearances decisive of the question, with regard to the +two suppositions which have been now considered, we may farther seek +confirmation of that supposition which has been found alone consistent +with appearances. + +If it be by means of heat and fusion that strata have been consolidated, +then, in proportion to the degree of consolidation they have undergone +from their original state, they should, _caeteris paribus_, abound more +with separations in their mass. But this conclusion is found consistent +with appearances. A stratum of porous sand-stone does not abound so much +with veins and cutters as a similar stratum of marble, or even a +similar stratum of sand-stone that is more consolidated. In proportion, +therefore, as strata have been consolidated, they are in general +intersected with veins and cutters; and in proportion as strata are +deep in their perpendicular section, the veins are wide, and placed at +greater distances. In like manner, when strata are thin, the veins are +many, but proportionally narrow. + +It is thus, upon chemical principles, to be demonstrated, That all the +solid strata of the globe have been condensed by means of heat, and +hardened from a state of fusion. But this proposition is equally to +be maintained from principles which are mechanical. The strata of the +globe, besides being formed of earths, are composed of sand, of gravel, +and fragments of hard bodies, all which may be considered as, in their +nature, simple; but these strata are also found composed of bodies which +are not simple, but are fragments of former strata, which had been +consolidated, and afterwards were broken and worn by attrition, so as +to be made gravel. Strata composed in this manner have been again +consolidated; and now the question is, By what means? + +If strata composed of such various bodies had been consolidated, by any +manner of concretion, from the fluidity of a dissolution, the hard and +solid bodies must be found in their entire state, while the interstices +between those constituent parts of the stratum are filled up. No partial +fracture can be conceived as introduced into the middle of a solid mass +of hard matter, without having been communicated from the surrounding +parts. But such partial separations are found in the middle of those +hard and solid masses; therefore, this compound body must have been +consolidated by other means than that of concretion from a state of a +solution. + +The Spanish marble already described, as well as many consolidated +strata of siliceous gravel, of which I have specimens, afford the +clearest evidence of this fact. These hard bodies are perfectly united +together, in forming the most solid mass; the contiguous parts of some +of the rounded fragments are interlaced together, as has already been +observed; and there are partial shrinkings of the mass forming veins, +traversing several fragments, but perfectly filled with the sparry +substance of the mass, and sometimes with parts of the stone distinctly +floating in the transparent body of spar. Now, there is not, besides +heat or fusion, any known power in nature by which these effects might +be produced. But such effects are general to all consolidated masses, +although not always so well illustrated in a cabinet specimen. + +Thus we have discovered a truth that is confirmed by every appearance, +so far as the nature of the subject now examined admits. We now return +to the general operation, of forming continents of those materials which +had been deposited at the bottom of the sea. + + +SECTION III. + +Investigation of the Natural Operations employed in the Production of +Land above the Surface of the Sea. + +We seek to know that operation by means of which masses of loose +materials, collected at the bottom of the sea, were raised above its +surface, and transformed into solid land. + +We have found, that there is not in this globe (as a planet revolving +in the solar system) any power or motion adapted to the purpose now in +view; nor, were there such a power, could a mass of simply collected +materials have continued any considerable time to resist the waves and +currents natural to the sea, but must have been quickly carried away, +and again deposited at the bottom of the ocean. But we have found, that +there had been operations, natural to the bowels of this earth; by which +those loose and unconnected materials have been cemented together, and +consolidated into masses of great strength and hardness; those bodies +are thus enabled to resist the force of waves and currents, and to +preserve themselves, for a sufficient time, in their proper shape and +place, as land above the general surface of the ocean. + +We now desire to know, how far those internal operations of the globe, +by which solidity and stability are procured to the beds of loose +materials, may have been also employed in raising up a continent of +land, to remain above the surface of the sea. + +There is nothing so proper for the erection of land above the level of +the ocean, as an expansive power of sufficient force, applied directly +under materials in the bottom of the sea, under a mass that is proper +for the formation of land when thus erected. The question is not, how +such a power may be procured; such a power has probably been employed. +If, therefore, such a power should be consistent with that which we +found had actually been employed in preparing the erected mass; or, +if such a power is to be reasonably concluded as accompanying those +operations which we have found natural to the globe, and situated in the +very place where this expansive power appears to be required, we should +thus be led to perceive, in the natural operations of the globe, a power +as efficacious for the elevation of what had been at the bottom of the +sea into the place of land, as it is perfect for the preparation of +those materials to serve the purpose of their elevation. + +In opposition to this conclusion, it will not be allowed to allege; that +we are ignorant how such a power might be exerted under the bottom of +the ocean; for, the present question is not, what had been the cause of +heat, which has appeared to have been produced in that place, but if +this power of heat, which has certainly been exerted at the bottom of +the ocean for consolidating strata, had been employed also for another +purpose, that is, for raising those strata into the place of land. + +We may, perhaps, account for the elevation of land, by the same cause +with that of the consolidation of strata, already investigated, without +explaining the means employed by nature in procuring the power of heat, +or showing from what general source of action this particular power had +been derived; but, by finding in subterranean heat a cause for any other +change, besides the consolidation of porous or incoherent bodies, we +shall generalise a fact, or extend our knowledge in the explanation of +natural appearances. + +The power of heat for the expansion of bodies, is, so far as we know, +unlimited; but, by the expansion of bodies placed under the strata at +the bottom of the sea, the elevation of those strata may be effected; +and the question now to be resolved regards the actual exertion of +this power of expansion. How far it is to be concluded as having been +employed in the production of this earth above the level of the sea. + +Before attempting to resolve that question, it may be proper to observe, +there has been exerted an extreme degree of heat below the strata formed +at the bottom of the sea; and this is precisely the action of a power +required for the elevation of those heated bodies into a higher place. +Therefore, if there is no other way in which we may conceive this event +to have been brought about, consistent with the present state of things, +or what actually appears, we shall have a right to conclude, that such +had been the order of procedure in natural things, and that the +strata formed at the bottom of the sea had been elevated, as well as +consolidated, by means of subterraneous heat. + +The consolidation of strata by means of fusion or the power of heat, has +been concluded from the examination of nature, and from finding, that +the present state of things is inconsistent with any other supposition. +Now, again, we are considering the only power that may be conceived as +capable of elevating strata from the bottom of the sea, and placing such +a mass above the surface of the water. It is a truth unquestionable, +that what had been originally at the bottom of the sea, is at present +the highest of our land. In explaining this appearance, therefore, no +other alternative is left, but either to suppose strata elevated by the +power of heat above the level of the present sea, or the surface of the +ocean reduced many miles below the height at which it had subsisted +during the collection and induration of the land which we inhabit. + +Now, if, on the one hand, we are to suppose no general power of +subterraneous fire or heat, we leave to our theory no means for the +retreat of the sea, or the lowering of its surface; if, on the other +hand, we are to allow the general power of subterraneous heat, we cannot +have much difficulty in supposing, either the surface of the sea to have +subsided, or the bottom of the ocean, in certain parts, to have been +raised by a subterranean power above the level of its surface, according +as appearances shall be found to require the one or other of those +conclusions. Here, therefore, we are again remitted to the history of +nature, in order to find matter of fact by which this question may be +properly decided. + +If the present land had been discovered by the subsiding of the waters, +there has not been a former land, from whence materials had been +procured for the construction of the present, when at the bottom of the +sea; for, there is no vestige remaining of that land, the whole land of +the present earth having been formed evidently at the bottom of the sea. +Neither could the natural productions of the sea have been accumulated, +in the shape in which we now find them, on the surface of this earth; +for, How should the Alps and Andes have been formed within the sea +from the natural productions of the water? Consequently, this is a +supposition inconsistent with every natural appearance. + +The supposition, therefore, of the subsidence of the former ocean, +for the purpose of discovering the present land, is beset with more +difficulty than the simple erection of the bottom of the former ocean; +for, _first_, There is a place to provide for the retirement of the +waters of the ocean; and, _2dly_, There is required a work of equal +magnitude; this is, the swallowing up of that former continent, which +had procured the materials of the present land. + +On the one hand, the subsiding of the surface of the ocean would but +make the former land appear the higher; and, on the other, the sinking +the body of the former land into the solid globe, so as to swallow up +the greater part of the ocean after it, if not a natural impossibility, +would be at least a superfluous exertion of the power of nature. Such an +operation as this would discover as little wisdom in the end elected, as +in the means appropriated to that end; for, if the land be not wasted +and worn away in the natural operations of the globe, Why make such a +convulsion in the world in order to renew the land? If, again, the land +naturally decays, Why employ so extraordinary a power, in order to hide +a former continent of land, and puzzle man? + +Let us now consider how far the other proposition, of strata being +elevated by the power of heat above the level of the sea, may be +confirmed from the examination of natural appearances. + +The strata formed at the bottom of the ocean are necessarily horizontal +in their position, or nearly so, and continuous in their horizontal +direction or extent. They may change, and gradually assume the nature of +each other, so far as concerns the materials of which they are formed; +but there cannot be any sudden change, fracture, or displacement, +naturally in the body of a stratum. But, if these strata are cemented by +the heat of fusion, and erected with an expansive power acting below, +we may expect to find every species of fracture, dislocation, and +contortion, in those bodies, and every degree of departure from a +horizontal towards a vertical position. + +The strata of the globe are actually found in every possible position: +For, from horizontal, they are frequently found vertical; from +continuous, they are broken and separated in every possible direction; +and, from a plane, they are bent and doubled. It is impossible that they +could have originally been formed, by the known laws of nature, in their +present state and position; and the power that has been necessarily +required for their change, has not been inferior to that which might +have been required for their elevation from the place in which they had +been formed. + +In this cafe, natural appearances are not anomalous. They are, indeed, +infinitely various, as they ought to be, according to the rule; but all +those varieties in appearances conspire to prove one general truth, viz. +That all which we see had been originally composed according to certain +principles, established in the constitution of the terraqueous globe; +and that those regular compositions had been afterwards greatly changed +by the operations of another power, which had introduced apparent +confusion among things first formed in order and by rule. + +It is concerning the operation of this second power that we are now +inquiring; and here the apparent irregularity and disorder of the +mineral regions are as instructive, with regard to what had been +transacted in a former period of time, as the order and regularity of +those same regions are conclusive, in relation to the place in which a +former state of things had produced that which, in its changed state, we +now perceive. + +We are now to conclude, that the land on which we dwell had been +elevated from a lower situation by the same agent which had been +employed in consolidating the strata, in giving them stability, and +preparing them for the purpose of the living world. This agent is matter +actuated by extreme heat, and expanded with amazing force. + +If this has been the case, it will be reasonable to expect, that some of +the expanded matter might be found condensed in the bodies which have +been heated by that igneous vapour; and that matter, foreign to the +strata, may have been thus introduced into the fractures and separations +of those indurated masses. + +We have but to open our eyes to be convinced of this truth. Look into +the sources of our mineral treasures; ask the miner, from whence has +come the metal into his vein? Not from the earth or air above,--not from +the strata which the vein traverses; these do not contain one atom of +the minerals now considered. There is but one place from whence these +minerals may have come; this is the bowels of the earth, the place of +power and expansion, the place from whence must have proceeded that +intense heat by which loose materials have been consolidated into rocks, +as well as that enormous force by which the regular strata have been +broken and displaced. + +Our attention is here peculiarly called upon, where we have the +opportunity of examining those mineral bodies, which have immediately +proceeded from the unknown region, that place of power and energy which +we want to explore; for, if such is the system of the earth, that +materials are first deposited at the bottom of the ocean, there to be +prepared in a certain manner, in order to acquire solidity, and then to +be elevated into the proper place of land, these mineral veins, which +contain matter absolutely foreign to the surface of the earth, afford +the most authentic information with regard to the operations which we +want to understand. It is these veins which we are to consider as, +in some measure, the continuation of that mineral region, which lies +necessarily out of all possible reach of our examination. It is, +therefore, peculiarly interesting to know the state in which things +are to be found in this place, which may be considered as intermediate +between the solid land, upon the one hand, and the unknown regions of +the earth, upon the other. + +We are now to examine those mineral veins; and these may be considered, +first, in relation to their form, independent of their substance or +particular contents; and, secondly, in relation to the contained bodies, +independent of their form. + +In examining consolidated strata, we remarked veins and cutters as a +proof of the means by which those bodies had been consolidated. In that +case, the formation of these veins is a regulated process, determined +by the degree of fusion, and the circumstances of condensation or +refrigeration. In respect of these, the mineral veins now to be examined +are anomalous. They are; but we know not why or how. We see the effect; +but, in that effect, we do not see the cause. We can say, negatively, +that the cause of mineral veins is not that by which the veins and +fissures of consolidated strata have been formed; consequently, that +it is not the measured contraction and regulated condensation of the +consolidated land which has formed those general mineral veins; however, +veins, similar in many respects, have been formed by the cooperation of +this cause. + +Having thus taken a view of the evident distinction between the veins or +contractions that are particular to the consolidated body in which they +are found, and those more general veins which are not limited to that +cause, we may now consider what is general in the subject, or what is +universal in these effects of which we wish to investigate the cause. + +The event of highest generalization or universality, in the form of +those mineral veins, is fracture and dislocation. It is not, like that +of the veins of strata, simple separation and measured contraction; it +is violent fracture and unlimited dislocation. In the one case, the +forming cause is in the body which is separated; for, after the body had +been actuated by heat, it is by the reaction of the proper matter of the +body, that the chasm which constitutes the vein is formed. In the other +case, again, the cause is extrinsic in relation to the body in which the +chasm is formed. There has been the most violent fracture and divulsion; +but the cause is still to seek; and it appears not in the vein; for it +is not every fracture and dislocation of the solid body of our earth, in +which minerals, or the proper substances of mineral veins, are found. + +We are now examining matter of fact, real effects, from whence we would +investigate the nature of certain events which do not now appear. Of +these, two kinds occur; one which has relation to the hardness and +solidity, or the natural constitution of the body; the other, to its +shape or local situation. The first has been already considered; the +last is now the subject of inquiry. + +But, in examining those natural appearances, we find two different kinds +of veins; the one necessarily connected with the consolidating cause; +the other with that cause of which we now particularly inquire. For, +in those great mineral veins, violent fracture and dislocation is the +principle; but there is no other principle upon which strata, or masses +formed at the bottom of the sea, can be placed at a height above its +surface. Hence, in those two different operations, of forming mineral +veins, and erecting strata from a lower to a higher place, the principle +is the same; for, neither can be done without violent fracture and +dislocation. + +We now only want to know, how far it is by the same power, as well as +upon the same principle, that these two operations have been made. +An expansive force, acting from below, is the power most proper for +erecting masses; but whether it is a power of the same nature with that +which has been employed in forming mineral veins, will best appear in +knowing the nature of their contents. These, therefore, may be now +considered. + +Every species of fracture, and every degree of dislocation and +contortion, may be perceived in the form of mineral veins; and there is +no other general principle to be observed in examining their form. But, +in examining their contents, some other principle may appear, so far as, +to the dislocating power or force, there may be superadded matter, by +which something in relation to the nature of the power may be known. +If, for example, a tree or a rock shall be found simply split asunder, +although there be no doubt with regard to some power having been applied +in order to produce the effect, yet we are left merely to conjecture at +the power. But when wedges of wood or iron, or frozen water, should be +found lodged in the cleft, we might be enabled, from this appearance, to +form a certain judgment with regard to the nature of the power which +had been applied. This is the case with mineral veins. We find them +containing matter, which indicates a cause; and every information in +this case is interesting to the theory. + +The substances contained in mineral veins are precisely the same with +those which, in the former section, we have considered as being made +instrumental in the consolidation of strata; and they are found mixed +and concreted in every manner possible. + +But, besides this evidence for the exertion of extreme heat, in that +process by which those veins were filled, there is another important +observation to be gathered from the inspection of this subject. There +appears to have been a great mechanical power employed in the filling of +these veins, as well as that necessarily required in making the first +fracture and divulsion. + +This appears from the order of the contents, or filling of these veins, +which is a thing often observed to be various and successive. But what +it is chiefly now in view to illustrate, is that immense force which is +manifested in the fracture and dispersion of the solid contents which +had formerly filled those veins. Here we find fragments of rock and spar +floating in the body of a vein filled with metallic substances; there, +again, we see the various fragments of metallic masses floating in the +sparry and siliceous contents. + +One thing is demonstrable from the inspection of the veins and their +contents; this is, the successive irruptions of those fluid substances +breaking the solid bodies which they meet, and floating those fragments +of the broken bodies in the vein. It is very common to see three +successive series of those operations; and all this may be perceived in +a small fragment of stone, which a man of science may examine in his +closet, often better than descending to the mine, where all the examples +are found on an enlarged scale. + +Let us now consider what power would be required to force up, from the +most unfathomable depth of the ocean, to the Andes or the Alps, a column +of fluid metal and of stone. This power cannot be much less than that +required to elevate the highest land upon the globe. Whether, therefore, +we shall consider the general veins as having been filled by mineral +steams, or by fluid minerals, an elevating power of immense force is +still required, in order to form as well as fill those veins. But such a +power acting under the consolidated masses at the bottom of the sea, is +the only natural means for making those masses land. + +If such have been the operations that are necessary for the production +of this land; and if these operations are natural to the globe of this +earth, as being the effect of wisdom in its contrivance, we shall +have reason to look for the actual manifestation of this truth in the +phaenomena of nature, or those appearances which more immediately +discover the actual cause in the perceived effect. + +To see the evidence of marble, a body that is solid, having been formed +of loose materials collected at the bottom of the sea, is not always +easy, although it may be made abundantly plain; and to be convinced that +this calcareous stone, which calcines so easily in our fires, should +have been brought into fusion by subterraneous heat, without suffering +calcination, must require a chain of reasoning which every one is not +able to attain[13]. But when fire bursts forth from the bottom of the +sea, and when the land is heaved up and down, so as to demolish cities +in an instant, and split asunder rocks and solid mountains, there +is nobody but must see in this a power, which may be sufficient to +accomplish every view of nature in erecting land, as it is situated in +the place most advantageous for that purpose. + +[Note 13: Mr le Chevalier de Dolomieu, in considering the different +effects of heat, has made the following observation; Journal de +Physique, Mai 1792. + +"Je dis _le feu tel que nous l'employons_ pour distinguer le feu naturel +des volcans, du feu de nos fourneaux et de celui de nos chalumeaux. Nous +sommes obliges de donner une grande activite a son action pour suppleer +et au volume qui ne seroit pas a notre disposition et au tems que nous +sommes forces de menager, et cette maniere d'appliquer une chaleur +tres-active, communique le mouvement et le desordre jusques dans les +molecules constituantes. Agregation et composition, tout est trouble. +Dans les volcans la grand masse du feu supplee a son intensite, le +tems remplace son activite, de maniere qu'il tourmente moins les corps +fournis a son action; il menage leur composition en relachant leur +agregation, et les pierres qui eut ete rendues fluides par l'embrasement +volcanique peuvent reprendre leur etat primitif; la plupart des +substances qu'un feu plus actif auroit expulsees y restent encore. Voila +pourquoi les laves ressemblent tellement aux pierres naturelles des +especes analogues, qu'elles ne peuvent en etre distinguees; voila +egalement pourquoi les verres volcaniques eux-meme renferment encore des +substances elastiques qui les font boursoufler lorsque nous les fondons +de nouveau, et pourquoi ces verres blanchissent aussi, pour lors, par +la dissipation, d'une substance grasse qui a resiste a la chaleur des +volcans, et que volatilise la chaleur par laquelle nous obtenons leur +second fusion." + +No doubt, the long application of heat may produce changes in bodies +very different from those which are occasioned by the sudden application +of a more intense heat; but still there must be sufficient intensity in +that power, so as to cause fluidity, without which no chemical change +can be produced in bodies. The essential difference, however, between +the natural heat of the mineral regions, and that which we excite upon +the surface of the earth, consists in this; that nature applies heat +under circumstances which we are not able to imitate, that is, under +such compression as shall prevent the decomposition of the constituent +substances, by the separation of the more volatile from the more fixed +parts. This is a circumstance which, so far as I know, no chemist +or naturalist has hitherto considered; and it is that by which the +operations of the mineral regions must certainly be explained. Without +attending to this great principle in the mineralizing operations +of subterraneous fire, it is impossible to conceive the fusion and +concretion of those various bodies, which we examine when brought up to +the surface of the earth.] + +The only question, therefore, which it concerns us to decide at present, +is, Whether those operations of extreme heat, and violent mechanic +force, be only in the system as a matter of accident; or if, on the +contrary, they are operations natural to the globe, and necessary in the +production of such land as this which we inhabit? The answer to this is +plain: These operations of the globe remain at present with undiminished +activity, or in the fullness of their power. + +A stream of melted lava flows from the sides of Mount Aetna. Here is a +column of weighty matter raised from a great depth below, to an immense +height above, the level of the sea, and rocks of an enormous size +are projected from its orifice some miles into the air. Every one +acknowledges that here is the liquefying power and expansive force of +subterranean fire, or violent heat. But, that Sicily itself had been +raised from the bottom of the ocean, and that the marble called Sicilian +Jasper, had its solidity upon the same principle with the lava, would +stumble many a naturalist to acknowledge. Nevertheless, I have in my +possession a table of this marble, from which it is demonstrable, that +this calcareous stone had flowed, and been in such a state of fusion and +fluidity as lava. + +Here is a comparison formed of two mineral substances, to which it is of +the highest importance to attend. The solidity and present state of the +one of these is commonly thought to be the operation of fire; of the +other, again, it is thought to be that of water. This, however, is not +the case. The immediate state and condition of both these bodies is now +to be considered as equally the effect of fire or heat. The reason of +our forming such a different judgment with regard to these two subjects +is this; we see, in the one case, the more immediate connection of the +cause and the effect, while, in the other, we have only the effects from +whence we are in science to investigate the cause. + +But, if it were necessary always to see this immediate connection, in +order to acknowledge the operation of a power which, at present, is +extinguished in the effect, we should lose the benefit of science, or +general principles, from whence particulars may be deduced, and we +should be able to reason no better than the brute. Man is made for +science; he reasons from effects to causes, and from causes to effects; +but he does not always reason without error. In reasoning, therefore, +from appearances which are particular, care must be taken how we +generalise; we should be cautious not to attribute to nature, laws which +may perhaps be only of our own invention. + +The immediate question now before us is not, If the subterraneous fire, +or elevating power, which we perceive sometimes as operating with such +energy, be the consolidating cause of strata formed at the bottom of the +sea; nor, if that power be the means of making land appear above the +general surface of the water? for, though this be the end we want to +arrive at ultimately, the question at present in agitation respects the +laws of nature, or the generality of particular appearances. + +Has the globe within it such an active power as fits it for the +renovation of that part of its constitution which may be subject to +decay? Are those powerful operations of fire, or subterraneous heat, +which so often have filled us with terror and astonishment, to be +considered as having always been? Are they to be concluded as proper to +every part upon the globe, and as continual in the system of this earth? +If these points in question shall be decided in the affirmative, we can +be at no loss in ascertaining the power which has consolidated strata, +nor in explaining the present situation of those bodies, which had their +origin at the bottom of the sea. This, therefore, should be the object +of our pursuit; and in order to have demonstration in a case of physical +inquiry, we must again have recourse to the book of nature. + +The general tendency of heat is to produce fluidity and softness; as +that of cold is, on the contrary, to harden soft and fluid bodies. But +this softening power of heat is not uniform in its nature; it is made to +act with very different effect, according to the nature of the substance +to which it is applied. We are but limited in the art of increasing the +heat or the cold of bodies; we find, however, extreme difference in +their substances with respect to fusibility. + +A fusible substance, or mineral composition in a fluid state, is emitted +from those places of the earth at which subterraneous fire and expansive +force are manifested in those eruptive operations. In examining these +emitted bodies, men of science find a character for such productions, in +generalising the substance, and understanding the natural constitution +of those bodies. It is in this manner that such a person, finding a +piece of lava in any place of the earth, says with certainty, Here is a +stone which had congealed from a melted state. + +Having thus found a distinguishing character for those fused substances +called, in general, Lavas, and having the most visible marks for that +which had been actually a volcano, naturalists, in examining different +countries, have discovered the most undoubted proofs of many ancient +volcanos, which had not been before suspected. Thus, volcanos will +appear to be not a matter of accident, or as only happening in a +particular place, they are general to the globe, so far as there is +no place upon the earth that may not have an eruption of this kind; +although it is by no means necessary for every place to have had those +eruptions. + +Volcanos are natural to the globe, as general operations; but we are +not to consider nature as having a burning mountain for an end in her +intention, or as a principal purpose in the general system of this +world. The end of nature in placing an internal fire or power of heat, +and a force of irresistible expansion, in the body of this earth, is to +consolidate the sediment collected at the bottom of the sea, and to form +thereof a mass of permanent land above the level of the ocean, for the +purpose of maintaining plants and animals. The power appointed for this +purpose is, as on all other occasions, where the operation is important, +and where there is any danger of a shortcoming, wisely provided +in abundance; and there are contrived means for disposing of the +redundancy. These, in the present case, are our volcanos. + +A volcano is not made on purpose to frighten superstitious people +into fits of piety and devotion, nor to overwhelm devoted cities with +destruction; a volcano should be considered as a spiracle to the +subterranean furnace, in order to prevent the unnecessary elevation of +land, and fatal effects of earthquakes; and we may rest assured, that +they, in general, wisely answer the end of their intention, without +being in themselves an end, for which nature had exerted such amazing +power and excellent contrivance. + +Let us take a view of the most elevated places of the earth; if the +present theory is just, it is there that we should find volcanos. But is +not this the case? There are volcanos in the Andes; and round the Alps +we find many volcanos, which are in France upon the one side, and in +Germany upon the other, as well as upon the Italian side, where Vesuvius +still continues to exhibit violent eruptions. + +It is not meant to allege, that it is only upon the summit of a +continent volcanos should appear. Subterraneous fire has sometimes made +its appearance in bursting from the bottom of the sea. But, even in +this last case, land was raised from the bottom of the sea, before the +eruption made its exit into the atmosphere. It must also be evident, +that, in this case of the new island near Santorini, had the expansive +power been retained, instead of being discharged, much more land might +have been raised above the level of the ocean. + +Now, the eruption of that elastic force through the bottom of the sea, +may be considered as a waste of power in the operations of the globe, +where the elevation of indurated strata is an object in the exertion of +that power; whereas, in the centre of a continent sufficiently elevated +above the level of the sea, the eruption of that fiery vapour calculated +to elevate the land, while it may occasionally destroy the habitations +of a few, provides for the security and quiet possession of the many. + +In order to see the wisdom of this contrivance, let us consider the +two extreme places at which this eruption of ignited matter may be +performed. These are, on the one hand, within a continent of land, and, +on the other, at the bottom of the ocean. In the one case, the free +eruption of the expanding power should be permitted; because the purpose +for which it had been calculated to exist has been accomplished. In +the other, again, the free eruption of that powerful matter should be +repressed; because there is reserved for that power much of another +operation in that place. But, according to the wise constitution of +things, this must necessarily happen. The eruption of the fiery +vapour from volcanos on the continent or land, is interrupted only +occasionally, by the melted bodies flowing in the subterraneous +chimney; whereas, at the bottom of the ocean, the contact of the water +necessarily tends to close the orifice, by accumulating condensed matter +upon the weakest place. + +If this be a just theory of the natural operations of the globe, we +shall have reason to expect, that great quantities of this melted +matter, or fusible substance, may be found in form of lava, among the +strata of the earth, where there are no visible marks of any volcano, or +burning mountain, having existed. Here, therefore, is an important point +to be determined; for, if it shall appear that much of this melted +matter, analogous to lava, has been forced to flow among the strata +which had been formed at the bottom of the sea, and now are found +forming dry land above its surface, it will be allowed, that we have +discovered the secret operations of nature concocting future land, as +well as those by which the present habitable earth had been produced +from the bottom of the abyss. Here, therefore, we shall at present rest +the argument, with endeavouring to show that such is actually the case. + +It appears from Cronstedt's Mineralogy, that the rock-stone, called trap +by the Swedes, the amygdaloides and the schwarts-stein of the Germans, +are the same with the whin-stone of this country. This is also fully +confirmed by specimens from Sweden, sent me by my friend Dr Gahn. +Whatever, therefore, shall be ascertained with regard to our whin-stone, +may be so far generalized or extended to the countries of Norway, +Sweden, and Germany. + +The whin-stone of Scotland is also the same with the toad-stone of +Derbyshire, which is of the amygdaloides species; it is also the same +with the flagstone of the south of Staffordshire, which is a simple +whin-stone, or perfect trap. England, therefore, must be included in +this great space of land, the mineral operations of which we explore; +and also Ireland, of which the Giant's Causeway, and many others, are +sufficient proof. + +In the south of Scotland, there is a ridge of hills, which extends +from the west side of the island in Galloway to the east side in +Berwickshire, composed of granite, of schistus, and of siliceous strata. +The Grampians on the north, again, form another range of mountains of +the same kind; and between these two great fields of broken, tumbled, +and distorted strata, there lies a field of lesser hardness and +consolidation, in general; but a field in which there is a great +manifestation of subterraneous fire, and of exerted force. + +The strata in this space consist, in general, of sand-stone, coal, +lime-stone or marble, iron-stone, and marl or argillaceous strata, with +strata of analogous bodies, and the various compositions of these. But +what is to the present purpose is this, that, through all this space, +there are interspersed immense quantities of whinstone; a body which is +to be distinguished as very different from lava; and now the disposition +of this whin-stone is to be considered. + +Sometimes it is found in an irregular mass or mountain, as Mr Cronstedt +has properly observed; but he has also said, that this is not the case +in general. His words are: "It is oftener found in form of veins in +mountains of another kind, running commonly in a serpentine manner, +contrary or across to the direction of the rock itself." + +The origin of this form, in which the trap or whin-stone appears, is +most evident to inspection, when we consider that this solid body had +been in a fluid state, and introduced, in that state, among strata, +which preserved their proper form. The strata appear to have been +broken, and the two correspondent parts of those strata are separated to +admit the flowing mass of whin-stone. + +A fine example of this kind may be seen upon the south side of the +Earn, on the road to Crief. It is twenty-four yards wide, stands +perpendicular, and appears many feet above the surface of the ground. It +runs from that eastward, and would seem to be the same with that which +crosses the river Tay, in forming Campsy-lin above Stanley, as a lesser +one of the same kind does below it. I have seen it at Lednoc upon the +Ammon, where it forms a cascade in that river, about five or six +miles west of Campsy-lin. It appears to run from the Tay east through +Strathmore, so that it may be considered as having been traced for +twenty or thirty miles, and westwards to Drummond castle, perhaps much +farther. + +Two small veins of the same kind, only two or three feet wide, may be +seen in the bed of the Water of Leith, traversing the horizontal strata, +the one is above St Bernard's well, the other immediately below it. But, +more particularly, in the shire of Ayr, to the north of Irvine, there +are to be seen upon the coast, between that and Scarmorly, in the space +of about twenty miles, more than twenty or thirty such dykes (as they +are called) of whin-stone. Some of them are of a great thickness; and, +in some places, there is perceived a short one, running at right angles, +and communicating with other two that run parallel. + +There is in this country, and in Derbyshire[14], another regular +appearance of this stone, which Cronstedt has not mentioned. In this +case, the strata are not broken in order to have the whin-stone +introduced, they are separated, and the whin-stone is interjected in +form of strata, having various degrees of regularity, and being of +different thickness. On the south side of Edinburgh, I have seen, in +little more than the space of a mile from east to west, nine or ten +masses of whin-stone interjected among the strata. These masses of +whin-stone are from three or four to an hundred feet thick, running +parallel in planes inclined to the horizon, and forming with it an angle +of about twenty or thirty degrees, as may be seen at all times in the +hill of Salisbury Craggs. + +[Note 14: See Mr Whitehurst's Theory of the Earth.] + +Having thus described these masses, which have flowed by means of +heat among the strata of the globe, strata which had been formed by +subsidence at the bottom of the sea, it will now be proper to examine +the difference that subsists between these subterraneous lavas, as they +may be termed, and the analogous bodies which are proper lavas, in +having issued out of a volcano.[15] + +[Note 15: The Chevalier de Dolomieu, in his accurate examination of +Aetna and the Lipari islands, has very well observed the distinction of +these two different species of lavas; but without seeming to know the +principle upon which this essential difference depends. No bias of +system, therefore, can here be supposed as perverting the Chevalier's +view, in taking those observations; and these are interesting to the +present theory, as corresponding perfectly with the facts from whence it +has been formed. It will be proper to give the account of these in his +own words. + +La zeolite est tres-commune dans certains laves de l'Ethna; il seroit +peut-etre possible d'y en rencontrer des morceaux aussi gros que ceux +que fournit l'isle de Ferroe. Quoique cette substance semble ici +appartenir aux laves, je ne dirai cependant point que toutes les +zeolites soient volcaniques, ou unies a des matieres volcaniques; celles +que l'on trouve en Allemagne sont, dit-on, dans des circonstances +differentes; mais je doit annoncer que je n'ai trouve cette substance en +Sicile, que dans les seules laves qui evidemment ont coule dans la mer, +et qui out ete recouvertes par ses eaux. La zeolite des laves n'est +point une dejection volcanique, ni une production du feu, ni meme un +matiere que les laves aient enveloppee lorsqu'elles etoient fluides; +elle est le resultat d'une operation et d'une combinaison posterieure, +auxquelles les eaux de la mer ont concouru. Les laves qui n'ont pas ete +submergees, n'en contiennent jamais. J'ai trouve ces observations si +constantes, que par-tout ou je rencontrois de la zeolite, j'etois sur +de trouver d'autres preuves de submersion, et partout ou je voyois des +laves recouvertes des depots de l'eau, j'etois sur de trouver de la +zeolite, et un de ces faits m'a toujours indique l'autre. Je me suis +servi avec succes de cette observation pour diriger mes recherches, et +pour connoitre l'antiquite des laves. _Mineralogie de Volcans, par +M. Faujas de Saint-Fond_. Here would appear to be the distinction of +subterraneous lava, in which zeolite and calcareous spar may be found, +and that which has flowed from a volcano, in which neither of these are +ever observed.] + +There can be no doubt that these two different species of bodies have +had the same origin, and that they are composed of the same materials +nearly; but from the different circumstances Of their production, there +is formed a character to these bodies, by which, they may be perfectly +distinguished. The difference of those circumstances consists in this; +the one has been emitted to the atmosphere in its fluid state the other +only came to be exposed to the light in a long course of time, after it +had congealed under the compression of an immense load of earth, and +after certain operations, proper to the mineral regions, had been +exercised upon the indurated mass. This is the cause of the difference +between those erupted lavas, and our whin-stone, toad-stone, and the +Swedish trap, which may be termed subterraneous lava. The visible +effects of those different operations may now be mentioned. + +In the erupted lavas, those substances which are subject to calcine and +vitrify in our fires, suffer similar changes, when delivered from a +compression which had rendered them fixed, though in an extremely heated +state. Thus, a lava in which there is much calcareous spar, when it +comes to be exposed to the atmosphere, or delivered from the compressing +force of its confinement, effervesces by the explosion of its fixed +air; the calcareous earth, at the same time, vitrifies with the other +substances. Hence such violent ebullition in volcanos, and hence the +emission of so much pumice-stone and ashes, which are of the same +nature. + +In the body of our whin-stone, on the contrary, there is no mark of +calcination or vitrification. We frequently find in it much calcareous +spar, or the _terra calcarea aerata_, which had been in a melted state +by heat, and had been crystallized by congelation into a sparry form. +Such is the _lapis amygdaloides_, and many of our whin-stone rocks, +which contain pebbles crystallized and variously figured, both +calcareous, siliceous, and of a mixture in which both these substances +form distinct parts. The specimens of this kind, which I have from the +whin-stone or porphyry rock of the Calton-hill, exhibit every species +of mineral operation, in forming jasper, figured agate, and marble; and +they demonstrate, that this had been performed by heat or fusion. + +I do not mean to say, that this demonstration is direct; it is +conditional, and proceeds upon the supposition, that the basaltic or +porphyry rock, in which those specimens are found, is a body which had +been in a melted state. Now, this is a supposition for which I have +abundance of evidence, were it required; but naturalists are now +sufficiently disposed to admit that proposition; they even draw +conclusions from this fact, which, I think, they are not sufficiently +warranted in doing; that is, from this appearance, they infer the former +existence of volcanos in those places. For my part, though I have made +the most strict examination, I never saw any vestige of such an event. +That there are, in other countries, evident marks of volcanos which +have been long extinguished, is unquestionably true; but naturalists, +imagining that there are no other marks of subterraneous fire and +fusion, except in the production of a lava, attribute to a volcano, as +a cause, these effects, which only indicate the exertion of that power +which might have been the cause of a volcano. + +If the theory now given be just, a rock of marble is no less a mark +of subterraneous fire and fusion, than that of the basaltes; and the +flowing of basaltic streams among strata broken and displaced, affords +the most satisfactory evidence of those operations by which the body of +our land had been elevated above the surface of the sea; but it gives no +proof that the eruptive force of mineral vapours had been discharged in +a burning mountain. Now, this discharge is essential in the proper idea +of a volcano. + +Besides this internal mark of an unerupted lava in the substance of the +stone or body of the flowing mass, there are others which belong to it +in common with all other mineral strata, consolidated by subterraneous +fire, and changed from the place of their original formation; this is, +the being broken and dislocated, and having veins of foreign matter +formed in their separations and contractions. + +If these are mineral operations, proper to the lower regions of the +earth, and exerted upon bodies under immense compression, such things +will be sometimes found in the unerupted lavas, as well as in the +contiguous bodies with which they are associated. If, on the contrary, +these are operations proper to the surface of the earth, where the +dissolving power of water and air take place, and where certain +stalactical and ferruginous concretions are produced by these means; +then, in erupted lavas, we should find mineral concretions, which +concretions should be denied to bodies which had been consolidated at +the bottom of the sea; that is to say, where, without the operation of +subterraneous fire, no changes of that kind could have taken place, as +has already been observed. But in the unerupted species of lava, that +is to say, in our whin-stone, every species of mineral appearance is +occasionally to be found. Let those who have the opportunity to examine, +say, what arc to be found in proper lavas, that is, those of the erupted +kind. Sir William Hamilton informed me, when I showed him those mineral +veins and spars in our whin-stone, that he had never observed the like, +in lavas We have now formed some conclusions with regard to the nature +and production of those parts of the land of this globe which we +have had the means of examining perfectly; but; from the accounts of +travellers, and from, the specimens which are brought to us from distant +parts, we have reason to believe, that all the rest of the earth is +of the same nature with that which has been now considered. The great +masses of the earth are the same every where; and all the different +species of earths, of rocks or stone, which have as yet appeared, are to +be found in the little space of this our island. + +It is true, that there are peculiar productions in the mineral kingdom +which are rare, as being found only in few places; but these things are +merely accidental in relation to the land, for they belong in property +to those parts of the mineral region which we never see. Such are, the +diamond of the east, the platina of the west, and the tin of Cornwall, +Germany, and Sumatra. Gold and silver, though found in many countries, +do not appear to be immediately necessary in the production of a +habitable country. Iron, again, is universal in the operations of the +globe, and is found often in that profusion which equals its utility. +Between these two extremes, we find all other minerals, that is to say, +here and there in moderate quantity, and apparently in some proportion +to their use. But all these substances are to be considered as the +vapours of the mineral regions, condensed occasionally in the crevices +of the land; and it is only the rocks and strata (in which those mineral +veins are found) that are now examined with regard to their original +composition, at the bottom of the sea, as well as to that, operation by +which those bodies had been indurated in their substance, and elevated +from the place in which they had been formed. + +Thus, we have sufficient reason to believe, that, in knowing the +construction of the land in Europe, we know the constitution of the land +in every part of the globe. Therefore, we may proceed to form general +conclusions, from the knowledge of the mineral region, thus acquired in +studying those parts which are seen. + +Having thus found, _first_, That the consolidated and indurated masses +of our strata had suffered the effects of violent heat and fusion; +_2dly_, That those strata, which had been formed in a regular manner at +the bottom of the sea, have been violently bended, broken, and removed +from their original place and situation; and, _lastly_, Having now found +the most indubitable proof, that the melting, breaking, and removing +power of subterraneous fire, has been actually exerted upon this land +which we examine, we cannot hesitate in ascribing these operations as a +cause to those effects which are exposed to our view. Now, these may be +considered as consisting in the solid state and present situation of +those stratified bodies, originally formed by subsidence in the ocean; +appearances which cannot, in reason, be ascribed to any other cause, and +which, upon this principle, are perfectly explained. + +It is not meant to specify every particular in the means employed by +nature for the elevation of our land. It is sufficient to have shown, +that there is, in nature, means employed for the consolidating of +strata, formed originally of loose and incoherent materials; and that +those same means have also been employed in changing the place and +situation of those strata. But how describe an operation which man +cannot have any opportunity of perceiving? Or how imagine that, for +which, perhaps, there are not proper data to be found? We only know, +that the land is raised by a power which has for principle subterraneous +heat; but, how that land is preserved in its elevated station, is a +subject in which we have not even the means to form conjecture; at +least, we ought to be cautious how we indulge conjecture in a subject +where no means occur for trying that which is but supposition. + +We now proceed, from the facts which have been properly established, to +reason with regard to the duration of this globe, or the general view of +its operations, as a living world, maintaining plants and animals. + + +SECTION IV. + +System of Decay and Renovation observed in the Earth. + +Philosophers observing an apparent disorder and confusion in the solid +parts of this globe, have been led to conclude, that there formerly +existed a more regular and uniform state, in the constitution of this +earth; that there had happened some destructive change; and that the +original structure of the earth had been broken and disturbed by some +violent operation, whether natural, or from a super-natural cause. Now, +all these appearances, from which conclusions of this kind have been +formed, find the most perfect explanation in the theory which we have +been endeavouring to establish; for they are the facts from whence we +have reasoned, in discovering the nature and constitution of this earth: +Therefore, there is no occasion for having recourse to any unnatural +supposition of evil, to any destructive accident in nature, or to the +agency of any preternatural cause, in explaining that which actually +appears. + +It is necessary for a living or inhabited world, that this should +consist of land and water. It is also necessary, that the land should be +solid and stable, refilling, with great power, the violent efforts +of the ocean; and, at the same time, that this solid land should be +resolved by the influence of the sun and atmosphere, so as to decay, +and thus become a soil for vegetation. But these general intentions are +perfectly fulfilled in the constitution of our earth, which has been now +investigated. This great body being formed of different mixed masses, +having various degrees of hardness and solubility, proper soil for +plants is supplied from the gradual resolution of the solid parts; +fertility in those soils arises from the mixture of different elementary +substances; and stability is procured to that vegetable world, by the +induration of certain bodies, those rocks and stones, which protect the +softer masses of clay and soil. + +In this manner, also, will easily be explained those natural appearances +which diversify the surface of the earth for the use of plants and +animals, and those objects which beautify the face of nature for the +contemplation of mankind. Such are, the distinctions of mountains and +valleys, of lakes and rivers, of dry barren deserts and rich watered +plains, of rocks which stand apparently unimpaired by the lapse of time, +and sands which fluctuate with the winds and tides. All these are the +effects of steady causes; each of these has its proper purpose in the +system of the earth; and in that system is contained another, which is +that of living growing bodies, and of animated beings. + +But, besides this, man, the intellectual being, has, in this subject of +the mineral kingdom, the means of gratifying the desire of knowledge, a +faculty by which he is distinguished from the animal, and by which he +improves his mind in knowing causes. Man is not satisfied, like the +brute, in seeing things which are; he seeks to know how things have +been, and what they are to be. It is with pleasure that he observes +order and regularity in the works of nature, instead of being disgusted +with disorder and confusion; and he is made happy from the appearance of +wisdom and benevolence in the design, instead of being left to suspect +in the Author of nature, any of that imperfection which he finds in +himself. + +Let us now take a view of that system of mineral economy, in which may +be perceived every mark of order and design, of provident wisdom and +benevolence. + +We have been endeavouring to prove, that all the continents and islands +of this globe had been raised above the surface of the ocean; we have +also aimed at pointing out the cause of this translation of matter, as +well as of the general solidity of that which is raised to our view; +but however this theory shall be received, no person of observation can +entertain a doubt, that all, or almost all we see of this earth, had +been originally formed at the bottom of the sea. We have now another +object in our view; this is to investigate the operations of the globe, +at the time that the foundation of this land was laying in the waters of +the ocean, and to trace the existence and the nature of things, before +the present land appeared above the surface of the waters. We should +thus acquire some knowledge of the system according to which this world +is ruled, both in its preservation and production; and we might be thus +enabled to judge, how far the mineral system of the world shall appear +to be contrived with all the wisdom, which is so manifest in what are +termed the animal and vegetable kingdoms. + +It must not be imagined that this undertaking is a thing unreasonable +in its nature; or that it is a work necessarily beset with any +unsurmountable difficulty; for, however imperfectly we may fulfill this +end proposed, yet, so far as it is to natural causes that are to be +ascribed the operations of former time, and so far as, from the present +state of things, or knowledge of natural history, we have it in our +power to reason from effect to cause, there are, in the constitution of +the world, which we now examine, certain means to read the annals of a +former earth. + +The object of inquiry being the operations of the globe, during the time +that the present earth was forming at the bottom of the sea, we are now +to take a very general view of nature, without descending into those +particulars which so often occupy the speculations of naturalists, about +the present state of things. We are not at present to enter into any +discussion with regard to what are the primary and secondary mountains +of the earth; we are not to consider what is the first, and what the +last, in those things which now are seen; whatever is most ancient in +the strata which we now examine, is supposed to be collecting at the +bottom of the sea, during the period concerning which we are now to +inquire. + +We have already considered those operations which had been necessary +in forming our solid land, a body consisting of materials originally +deposited at the bottom of the ocean; we are now to investigate the +source from whence had come all those materials, from the collection of +which the present land is formed; and from knowing the state in +which those materials had existed, previously to their entering the +composition of our strata, we shall learn something concerning the +natural history of this world, while the present earth was forming in +the sea. + +We have already observed, that all the strata of the earth are composed +either from the calcareous relicts of sea animals, or from the +collection of such materials as we find upon our shores. At a gross +computation, there may perhaps be a fourth part of our solid land, which +is composed from the matter that had belonged to those animals. Now, +what a multitude of living creatures, what a quantity of animal economy +must have been required for producing a body of calcareous matter +which is interspersed throughout all the land of the globe, and which +certainly forms a very considerable part of that mass! Therefore, in +knowing how those animals had lived, or with what they had been fed, we +shall have learned a most interesting part of the natural history of +this earth; a part which it is necessary to have ascertained, in order +to see the former operations of the globe, while preparing the materials +of the present land. But, before entering upon this subject, let us +examine the other materials of which our land is formed. + +Gravel forms a part of those materials which compose our solid land; but +gravel is no other than a collection of the fragments of solid stones +worn round, or having their angular form destroyed by agitation in +water, and the attrition upon each other, or upon similar hard bodies. +Consequently, in finding masses of gravel in the composition of our +land, we must conclude, that there had existed a former land, on which +there had been transacted certain operations of wind and water, similar +to those which are natural to the globe at present, and by which new +gravel is continually prepared, as well as old gravel consumed or +diminished by attrition upon our shores. + +Sand is the material which enters, perhaps in greatest quantity, the +composition of our land. But sand, in general, is no other than small +fragments of hard and solid bodies, worn or rounded more or less by +attrition; consequently, the same natural history of the earth, which +is investigated from the masses of gravel, is also applicable to those +masses of sand which we find forming so large a portion of our present +land throughout all the earth[16]. + +[Note 16: Sand is a term that denotes no particular substance; although +by it is commonly meant a siliceous substance, as being by far the most +prevalent. Sand is one of the modifications, of size and shape, in a +hard body or solid substance, which may be infinitely diversified. The +next modification to be distinguished in mineral bodies is that of +gravel; and this differs in no respect from sand, except in point of +size. Next after gravel, in the order of ascent, come stones; and these +bear nearly the same relation to gravel as gravel does to sand. Now, +by stones is to be understood the fragments of rocks or solid mineral +bodies; and there is a perfect gradation from those stones to sand. +I have already endeavoured to explain the formation of those stony +substances; and now I am treating of a certain system of circulation, +which is to be found among minerals. + +M. de Luc censures me for not giving the origin of sand, of which I form +the strata of the earth. He seems to have misunderstood my treatise. I +do not pretend, as he does in his theory, to describe the beginning of +things; I take things such as I find them at present, and from these +I reason with regard to that which must have been. When, from a thing +which is well known, we explain another which is less so, we then +investigate nature; but when we imagine things without a pattern or +example in nature, then, instead of natural history, we write only +fable. + +M. de Luc, in the letter already mentioned, says, "that sand may be, and +I think it is, a substance which has formed _strata_ by _precipitation +in a liquid_." This is but an opinion, which may be either true or +false. If it be true, it is an operation of the mineral kingdom of which +I am ignorant. In all the sand which I have ever examined, I have never +seen any that might not be referred to the species of mineral substance +from which it had been formed. When this author shall have given us +any kind of information with regard to the production of sand _by +precipitation in a liquid_, it will then be time enough to think of +forming the strata of the earth with that sand.] + +Clay is now to be considered as the last of those materials of which +our strata are composed; but, in order to understand the nature of this +ingredient, something must be premised. + +Clay is a mixture of different earths or hard substances, in an +impalpable state. Those substances are chiefly the siliceous and +aluminous earths. Other earths are occasionally mixed in clays, or +perhaps always to be found in some small portion. But this does not +affect the general character of clay; it only forms a special variety in +the subject. A sensible or considerable portion of calcareous earth, in +the composition of clay, constitutes a marl, and a sufficient admixture +of sand, a loam. + +An indefinite variety of those compositions of clay form a large portion +of the present strata, all indurated and consolidated in various +degrees; but this great quantity of siliceous, argillaceous, and +other compound substances, in form of earth or impalpable sediment, +corresponds perfectly with that quantity of those same substances which +must have been prepared in the formation of so much gravel and sand, by +the attrition of those bodies in the moving waters. + +Therefore, from the consideration of those materials which compose the +present land, we have reason to conclude, that, during the time this +land was forming, by the collection of its materials at the bottom of +the sea, there had been a former land containing materials similar to +those which we find at present in examining the earth. We may also +conclude, that there had been operations similar to those which we +now find natural to the globe, and necessarily exerted in the actual +formation of gravel, sand, and clay. But what we have now chiefly in +view to illustrate is this, that there had then been in the ocean a +system of animated beings, which propagated their species, and which +have thus continued their several races to this day. + +In order to be convinced of that truth, we have but to examine the +strata of our earth, in which we find the remains of animals. In this +examination, we not only discover every genus of animal which at present +exists in the sea, but probably every species, and perhaps some species +with which at present we are not acquainted. There are, indeed, +varieties in those species, compared with the present animals which we +examine, but no greater varieties than may perhaps be found among the +same species in the different quarters of the globe. Therefore, the +system of animal life, which had been maintained in the ancient sea, had +not been different from that which now subsists, and of which it belongs +to naturalists to know the history. + +It is the nature of animal life to be ultimately supported from matter +of vegetable production. Inflammable matter may be considered as the +_pabulum_ of life. This is prepared in the bodies of living plants, +particularly in their leaves exposed to the sun and light. This +inflammable matter, on the contrary, is consumed in animal bodies, where +it produces heat or light, or both. Therefore, however animal matter, or +the pabulum of life, may circulate through a series of digesting powers, +it is constantly impaired or diminishing in the course of this economy, +and, without the productive power of plants, it would finally be +extinguished.[17] + +[Note 17: See Dissertations on different subjects of Natural Philosophy, +part II.] + +The animals of the former world must have been sustained during +indefinite successions of ages. The mean quantity of animal matter, +therefore, must have been preserved by vegetable production, and the +natural waste of inflammable substance repaired with continual addition; +that is to say, the quantity of inflammable matter necessary to the +animal consumption, must have been provided by means of vegetation. +Hence we must conclude, that there had been a world of plants, as well +as an ocean replenished with living animals. + +We are now, in reasoning from principles, come to a point decisive of +the question, and which will either confirm the theory, if it be just, +or confute our reasoning, if we have erred. Let us, therefore, open +the book of Nature, and read in her records, if there had been a world +bearing plants, at the time when this present world was forming at the +bottom of the sea. + +Here the cabinets of the curious are to be examined; but here some +caution is required, in order to distinguish things perfectly different, +which sometimes are confounded. + +Fossil wood, to naturalists in general, is wood dug up from under +ground, without inquiring whether this had been the production of the +present earth, or that which had preceded it in the circulation of land +and water. The question is important, and the solution of it is, in +general, easy. The vegetable productions of the present earth, however +deep they may be found buried beneath its surface, and however ancient +they may appear, compared with the records of our known times, are new, +compared with the solid land on which they grew; and they are only +covered with the produce of a vegetable soil, or the alluvion of the +present land on which we dwell, and on which they had grown. But the +fossil bodies which form the present subject of inquiry, belonged to +former land, and are found only in the sea-born strata of our present +earth. It is to these alone that we appeal, in order to prove the +certainty of former events. + +Mineralised wood, therefore, is the object now inquired after; that wood +which had been lodged in the bottom of the sea, and there composed part +of a stratum, which hitherto we have considered as only formed of the +materials proper to the ocean. Now, what a profusion of this species of +fossil wood is to be found in the cabinets of collectors, and even in +the hands of lapidaries, and such artificers of polished stones! In some +places, it would seem to be as common as the agate. + +I shall only mention a specimen in my own collection. It is wood +petrified with calcareous earth, and mineralised with pyrites. This +specimen of wood contains in itself, even without the stratum of stone +in which it is embedded, the most perfect record of its genealogy. +It had been eaten or perforated by those sea worms which destroy the +bottoms of our ships. There is the clearest evidence of this truth. +Therefore, this wood had grown upon land which flood above the level of +sea, while the present land was only forming at the bottom of the ocean. + +Wood is the most substantial part of plants, as shells are the more +permanent part of marine animals. It is not, however, the woody part +alone of the ancient vegetable world that is transmitted to us in +the record of our mineral pages. We have the type of many species +of foliage, and even of the most delicate flower; for, in this way, +naturalists have determined, according to the Linnaean system, the +species, or at least the genus, of the plant. Thus, the existence of a +vegetable system at the period now in contemplation, so far from being +doubtful, is a matter of physical demonstration. + +The profusion of this vegetable matter, delivered into the ocean, which +then generated land, is also evidenced in the amazing quantities of +mineral coal which is to be found in perhaps every region of the earth. + +Nothing can be more certain, than that all the coaly or bituminous +strata have had their origin from the substance of vegetable bodies +that grew upon the land. Those strata, tho', in general, perfectly +consolidated, often separate horizontally in certain places; and there +we find the fibrous or vascular structure of the vegetable bodies. +Consequently, there is no doubt of fossil coal being a substance +of vegetable production, however animal substances also may have +contributed in forming this collection of oleaginous or inflammable +matter. + +Having thus ascertained the state of a former earth, in which plants +and animals had lived, as well as the gradual production of the present +earth, composed from the materials of a former world, it must be +evident, that here are two operations which are necessarily consecutive. +The formation of the present earth necessarily involves the destruction +of continents in the ancient world; and, by pursuing in our mind the +natural operations of a former earth, we clearly see the origin of that +land, by the fertility of which, we, and all the animated bodies of the +sea, are fed. It is in like manner, that, contemplating the present +operations of the globe, we may perceive the actual existence of those +productive causes, which are now laying the foundation of land in the +unfathomable regions of the sea, and which will, in time, give birth to +future continents. + +But though, in generalising the operations of nature, we have arrived at +those great events, which, at first sight, may fill the mind with +wonder and with doubt, we are not to suppose, that there is any violent +exertion of power, such as is required in order to produce a great event +in little time; in nature, we find no deficiency in respect of time, nor +any limitation with regard to power. But time is not made to flow in +vain; nor does there ever appear the exertion of superfluous power, or +the manifestation of design, not calculated in wisdom to effect some +general end. + +The events now under consideration may be examined with a view to see +this truth; for it may be inquired, Why destroy one continent in order +to erect another? The answer is plain; Nature does not destroy a +continent from having wearied of a subject which had given pleasure, or +changed her purpose, whether for a better or a worse; neither does she +erect a continent of land among the clouds, to show her power, or to +amaze the vulgar man; Nature has contrived the productions of vegetable +bodies, and the sustenance of animal life, to depend upon the gradual +but sure destruction of a continent; that is to say, these two +operations necessarily go hand in hand. But with such wisdom has nature +ordered things in the economy of this world, that the destruction of one +continent is not brought about without the renovation of the earth in +the production of another; and the animal and vegetable bodies, for +which the world above the surface of the sea is leveled with its bottom, +are among the means employed in those operations, as well as the +sustenance of those living beings is the proper end in view. + +Thus, in understanding the proper constitution of the present earth, we +are led to know the source from whence had come all the materials which +nature had employed in the construction of the world which appears; a +world contrived in consummate wisdom for the growth and habitation of a +great diversity of plants and animals; and a world peculiarly adapted +to the purposes of man, who inhabits all its climates, who measures its +extent, and determines its productions at his pleasure. + +The whole of a great object or event fills us with wonder and +astonishment, when all the particulars, in the succession of which the +whole had been produced, may be considered without the least emotion. +When, for example, we behold the pyramids of Egypt, our mind is agitated +with a crowd of ideas that highly entertains the person who understands +the subject; but the carrying a heavy stone up to the top of a hill or +mountain would give that person little pleasure or concern. We wonder at +the whole operation of the pyramid, but not at any one particular part. + +The raising up of a continent of land from the bottom of the sea, is an +idea that is too great to be conceived easily in all the parts of its +operations, many of which are perhaps unknown to us; and, without being +properly understood, so great an idea may appear like a thing that is +imaginary. In like manner, the co-relative, or corresponding operation, +the destruction of the land, is an idea that does not easily enter into +the mind of man in its totality, although he is daily witness to part of +the operation. We never see a river in a flood, but we must acknowledge +the carrying away of part of our land, to be sunk at the bottom of the +sea; we never see a storm upon the coast, but we are informed of a +hostile attack of the sea upon our country; attacks which must, in time, +wear away the bulwarks of our soil, and sap the foundations of our +dwellings. Thus, great things are not understood without the analysing +of many operations, and the combination of time with many events +happening in succession. + +Let us now consider what is to be the subject of examination, and where +it is that we are to observe those operations which must determine +either the stability or the instability of this land on which we live. + +Our land has two extremities; the tops of the mountains, on the one +hand, and the sea-shores, on the other: It is the intermediate space +between these two, that forms the habitation of plants and animals. +While there is a sea-shore and a higher ground there is that which is +required in the system of the world: Take these away, and there would +remain an aqueous globe, in which the world would perish. But, in the +natural operations of the world, the land is perishing continually; and +this is that which now we want to understand. + +Upon the one extremity of our land, there is no increase, or there is no +accession of any mineral substance. That place is the mountain-top, on +which nothing is observed but continual decay. The fragments of the +mountain are removed in a gradual succession from the highest station to +the lowest. Being arrived at the shore, and having entered the dominion +of the waves, in which they find perpetual agitation, these hard +fragments, which had eluded the resolving powers natural to the surface +of the earth, are incapable of resisting the powers here employed for +the destruction of the land. By the attrition of one hard body upon +another, the moving stones and rocky shore, are mutually impaired. And +that solid mass, which of itself had potential liability against the +violence of the waves, affords the instruments of its own destruction, +and thus gives occasion to its actual instability. + +In order to understand the system of the heavens, it is necessary to +connect together periods of measured time, and the distinguished places +of revolving bodies. It is thus that system may be observed, or wisdom, +in the proper adapting of powers to an intention. In like manner, we +cannot understand the system of the globe, without seeing that progress +of things which is brought about in time, thus measuring the natural +operations of the earth with those of the heavens. This is properly the +business of the present undertaking. + +Our object is to know the time which had elapsed since the foundation of +the present continent had been laid at the bottom of the ocean, to the +present moment in which we speculate on these operations. The space is +long; the data for the calculations are, perhaps, deficient: No matter; +so far as we know our error, or the deficiency in our operation, we +proceed in science, and shall conclude in reason. It is not given to man +to know what things are truly in themselves, but only what those things +are in his thought. We seek not to know the precise measure of any +thing; we only understand the limits of a thing, in knowing what it is +not, either on the one side or the other. + +We are investigating the age of the present earth, from the beginning of +that body which was in the bottom of the sea, to the perfection of its +nature, which we consider as in the moment of our existence; and we have +necessarily another aera, which is collateral, or correspondent, in the +progress of those natural events. This is the time required, in the +natural operations of this globe, for the destruction of a former +earth; an earth equally perfect with the present and an earth equally +productive of growing plants and living animals. Now, it must appear, +that, if we had a measure for the one of those corresponding operations, +we would have an equal knowledge of the other. + +The formation of a future earth being in the bottom of the ocean, at +depths unfathomable to man, and in regions far beyond the reach of his +observation, here is a part of the process which cannot be taken as a +principle in forming an estimate of the whole. But, in the destruction +of the present earth, we have a process that is performed within the +limits of our observation; therefore, in knowing the measure of this +operation, we shall find the means of calculating what had passed on a +former occasion, as well as what will happen in the composition of a +future earth. Let us, therefore, now attempt to make this estimate of +time and labour. + +The highest mountain may be levelled with the plain from whence it +springs, without the loss of real territory in the land; but when the +ocean makes encroachment on the basis of our earth, the mountain, +unsupported, tumbles with its weight; and with the accession of hard +bodies, moveable with the agitation of the waves, gives to the sea the +power of undermining farther and farther into the solid basis of our +land. This is the operation which is to be measured; this is the mean +proportional by which we are to estimate the age of worlds that have +terminated, and the duration of those that are but beginning. + +But how shall we measure the decrease of our land? Every revolution of +the globe wears away some part of some rock upon some coast; but the +quantity of that decrease, in that measured time, is not a measurable +thing. Instead of a revolution of the globe, let us take an age. The age +of man does no more in this estimate than a single year. He sees, +that the natural course of things is to wear away the coast, with the +attrition of the sand and stones upon the shore; but he cannot find a +measure for this quantity which shall correspond to time, in order to +form an estimate of the rate of this decrease. + +But man is not confined to what he sees; he has the experience of former +men. Let us then go to the Romans and the Greeks in search of a measure +of our coasts, which we may compare with the present state of things. +Here, again, we are disappointed; their descriptions of the shores of +Greece and of Italy, and their works upon the coast, either give no +measure of a decrease, or are not accurate enough for such a purpose. + +It is in vain to attempt to measure a quantity which escapes our notice, +and which history cannot ascertain; and we might just as well attempt to +measure the distance of the stars without a parallax, as to calculate +the destruction of the solid land without a measure corresponding to the +whole. + +The description which Polybius has given of the Pontus Euxinus, with +the two opposite Bosphori, the Meotis, the Propontis, and the Port of +Byzantium, are as applicable to the present state of things as they were +at the writing of that history. The filling up of the bed of the +Meotis, an event which, to Polybius, appeared not far off, must also be +considered as removed to a very distant period, though the causes still +continue to operate as before. + +But there is a thing in which history and the present state of things do +not agree. It is upon the coast of Spain, where Polybius says there was +an island in the mouth of the harbour of New Carthage. At present, in +place of the island, there is only a rock under the surface of the +water. It must be evident, however, that the loss of this small island +affords no proper ground of calculation for the measure or rate of +wasting which could correspond to the coast in general; as neither +the quantity of what is now lost had been measured, nor its quality +ascertained. + +Let us examine places much more exposed to the fury of the waves and +currents than the coast of Carthagena, the narrow fretum, for example, +between Italy and Sicily. It does not appear, that this passage is +sensibly wider than when the Romans first had known it. The Isthmus of +Corinth is also apparently the same at present as it had been two or +three thousand years ago. Scilla and Charibdis remain now, as they had +been in ancient times, rocks hazardous for coasting vessels which had to +pass that strait. + +It is not meant by this to say, these rocks have not been wasted by the +sea, and worn by the attrition of moving bodies, during that space of +time; were this true, and that those rocks, the bulwarks of the land +upon those coasts, had not been at all impaired from that period, they +might remain for ever, and thus the system of interchanging the place of +sea and land upon this globe might be frustrated. It is only meant +to affirm, that the quantity which those rocks, or that coast, have +diminished from the period of our history, has either been too small +a thing for human observation, or, which is more probable, that no +accurate measurement of the subject, by which this quantity of decrease +might have been ascertained, had been taken and recorded. It must be +also evident, that a very small operation of an earthquake would be +sufficient to render every means of information, in this manner of +mensuration, unsatisfactory or precarious. + +Pliny says Italy was distant from Sicily a mile and a half; but we +cannot suppose that this measure was taken any otherwise than by +computation, and such a measure is but little calculated to afford us +the just means of a comparison with the present distance. He also says, +indeed, that Sicily had been once joined with Italy. His words are: +"Quondam Brutio agro cohaerens, mox interfuso mari avulsa.[18]" But all +that we can conclude from this history of Pliny is, that, in all times, +to people considering the appearances of those two approached coasts, +it had seemed probable, that the sea formed a passage between the two +countries which had been once united; in like manner as is still more +immediately perceived, in that smaller disjunction which is made between +the island of Anglesey and the continent of Wales. + +[Note 18: Lib. 3. cap. 8.] + +The port of Syracuse, with the island which forms the greater and +lesser, and the fountain of Arethusa, the water of which the ancients +divided from the sea with a wall, do not seem to be altered. From Sicily +to the coast of Egypt, there is an uninterrupted course of sea for a +thousand miles; consequently, the wind, in such a stretch of sea, should +bring powerful waves against those coasts: But, on this coast of Egypt, +we find the rock on which was formerly built the famous tower of Pharos; +and also, at the eastern extremity of the port Eunoste, the sea-bath, +cut in the solid rock upon the shore. Both those rocks, buffeted +immediately with the waves of the Mediterranean sea, are, to all +appearance, the same at this day as they were in ancient times.[19] + +[Note 19: Lettres sur l'Egypte, M. Savary.] + +Many other such proofs will certainly occur, where the different parts +of those coasts are examined by people of observation and intelligence. +But it is enough for our present purpose, that this decrease of the +coasts in general has not been observed; and that it is as generally +thought, that the land is gaining upon the sea, as that the sea is +gaining upon the land. + +To sum up the argument, we are certain, that all the coasts of the +present continents are wasted by the sea, and constantly wearing away +upon the whole; but this operation is so extremely slow, that we cannot +find a measure of the quantity in order to form an estimate: Therefore, +the present continents of the earth, which we consider as in a state of +perfection, would, in the natural operations of the globe, require a +time indefinite for their destruction. + +But, in order to produce the present continents, the destruction of a +former vegetable world was necessary; consequently, the production of +our present continents must have required a time which is indefinite. +In like manner, if the former continents were of the same nature as the +present, it must have required another space of time, which also is +indefinite, before they had come to their perfection as a vegetable +world. + +We have been representing the system of this earth as proceeding with +a certain regularity, which is not perhaps in nature, but which is +necessary for our clear conception of the system of nature. The +system of nature is certainly in rule, although we may not know every +circumstance of its regulation. We are under a necessity, therefore, of +making regular suppositions, in order to come at certain conclusions +which may be compared with the present state of things. + +It is not necessary that the present land should be worn away and +wasted, exactly in proportion as new land shall appear; or, conversely, +that an equal proportion of new land should always be produced as the +old is made to disappear. It is only required, that at all times, there +should be a just proportion of land and water upon the surface of the +globe, for the purpose of a habitable world. + +Neither is it required in the actual system of this earth, that every +part of the land should be dissolved in its structure, and worn away by +attrition, so as to be floated in the sea. Parts of the land may often +sink in a body below the level of the sea, and parts again may be +restored, without waiting for the general circulation of land and water, +which proceeds with all the certainty of nature, but which advances with +an imperceptible progression. Many of such apparent irregularities may +appear without the least infringement on the general system. That system +is comprehended in the preparation of future land at the bottom of the +ocean, from those materials which the dissolution and attrition of +the present land may have provided, and from those which the natural +operations of the sea afford. + +In thus accomplishing a certain end, we are not to limit nature with the +uniformity of an equable progression, although it be necessary in our +computations to proceed upon equalities. Thus also, in the use of means, +we are not to prescribe to nature those alone which we think suitable +for the purpose, in our narrow view. It is our business to learn of +nature (that is by observation) the ways and means, which in her wisdom +are adopted; and we are to imagine these only in order to find means for +further information, and to increase our knowledge from the examination +of things which actually have been. It is in this manner, that intention +may be found in nature; but this intention is not to be supposed, or +vainly imagined, from what we may conceive to be. + +We have been now supposing, that the beginning of our present earth had +been laid in the bottom of the ocean, at the completion of the former +land; but this was only for the sake of distinctness. The just view is +this, that when the former land of the globe had been complete, so as +to begin to waste and be impaired by the encroachment of the sea, the +present land began to appear above the surface of the ocean. In this +manner we suppose a due proportion to be always preserved of land and +water upon the surface of the globe, for the purpose of a habitable +world, such as this which we possess. We thus, also, allow time and +opportunity for the translation of animals and plants to occupy the +earth. + +But, if the earth on which we live, began to appear in the ocean at +the time when the last began to be resolved, it could not be from the +materials of the continent immediately preceding this which we examine, +that the present earth had been constructed; for the bottom of the ocean +must have been filled with materials before land could be made to appear +above its surface. + +Let us suppose that the continent, which is to succeed our land, is at +present beginning to appear above the water in the middle of the Pacific +Ocean, it must be evident, that the materials of this great body, which +is formed and ready to be brought forth, must have been collected from +the destruction of an earth, which does not now appear. Consequently, +in this true statement of the case, there is necessarily required the +destruction of an animal and vegetable earth prior to the former land; +and the materials of that earth which is first in our account, must have +been collected at the bottom of the ocean, and begun to be concocted for +the production of the present earth, when the land immediately preceding +the present had arrived at its full extent. + +This, however, alters nothing with regard to the nature of those +operations of the globe. The system is still the same. It only protracts +the indefinite space of time in its existence, while it gives us a view +of another distinct period of the living world; that is to say, the +world which we inhabit is composed of the materials, not of the earth +which was the immediate predecessor of the present, but of the earth +which, in ascending from the present, we consider as the third, and +which had preceded the land that was above the surface of the sea, while +our present land was yet beneath the water of the ocean. Here are three +distinct successive periods of existence, and each of these is, in our +measurement of time, a thing of indefinite duration. + +We have now got to the end of our reasoning; we have no data further +to conclude immediately from that which actually is: But we have got +enough; we have the satisfaction to find, that in nature there is +wisdom, system, and consistency. For having, in the natural history of +this earth, seen a succession of worlds, we may from this conclude that +there is a system in nature; in like manner as, from seeing revolutions +of the planets, it is concluded, that there is a system by which they +are intended to continue those revolutions. But if the succession of +worlds is established in the system of nature, it is in vain to look for +any thing higher in the origin of the earth. The result, therefore, of +this physical inquiry is, that we find no vestige of a beginning,--no +prospect of an end. + + + +CHAPTER II. + +An Examination of Mr KIRWAN'S Objections to the Igneous Origin of Stony +Substances. + +A theory which is founded on a new principle, a theory which has to make +its way in the public mind by overturning the opinions commonly received +by philosophising men, and one which has nothing to recommend it but the +truth of its principles, and the view of wisdom or design to which it +leads, neither of which may perhaps be perceived by the generality of +people, such a theory, I say, must meet with the strongest opposition +from the prejudices of the learned, and from the superstition of those +who judge not for themselves in forming their notions, but look up to +men of science for authority. Such is the case with some part of the +Theory of the Earth, which I have given, and which will probably give +offence to naturalists who have espoused an opposite opinion. In order, +then, to obtain the approbation of the public, it may not be enough to +give a theory that should be true, or altogether unexceptionable it may +be necessary to defend every point that shall be thought exceptionable +by other theorists, and to show the fallacy of every learned objection +that may be made against it. It is thus, in general, that truth and +error are forced to struggle together, in the progress of science; and +it is only in proportion as science removes erroneous conceptions, which +are necessarily in the constitution of human knowledge, that truth will +find itself established in natural philosophy. + +Mr Kirwan has written a dissertation, entitled, _Examination of the +Supposed Igneous Origin of Stony Substances_, which was read in the +Royal Irish Academy. The object of that dissertation is to state certain +objections, which have occurred to him, against the Theory of the Earth +published in the Transactions of the Edinburgh Royal Society; and he has +attacked that theory in all the points where it appears to him to be +vulnerable. It is to these objections that I am now to give an answer. +The authority given to this dissertation, by the Royal Irish Academy, +as well as the reputation of the author, make it necessary for me +to endeavour to put in their true light the facts alleged in that +performance, and to analyse the arguments employed, in order to judge of +the reasoning by which the theory of mineral fusion is refuted in this +Examination. + +A theory founded on truth, and formed according to the proper rules of +science, can ever suffer from a strict examination, by which it would +be but the more and more confirmed. But, where causes are to be traced +through a chain of various complicated effects, an examination not +properly conducted upon accurate analytical principles, instead of +giving light upon a subject in which there had been obscurity and doubt, +may only serve to perplex the understanding, and bring confusion into a +subject which was before sufficiently distinct. To redress that evil, +then, must require more labour and some address; and this is an +inconveniency that may be looked for, more or less, in every +controversial discussion. + +I do not mean to enter any farther into the defence of my theory in +this chapter, than what is necessary to answer a man of science and +respectability, who has stated his objections. The observations which +he has made appear to me to be founded on nothing more than common +prejudice, and misconceived notions of the subject. I am therefore +to point out that erroneous train of reasoning, into which a hasty +superficial view of things, perhaps, has led the patron of an opposite +opinion to see my theory in an unfavourable light. This, however, is not +all; for, that train of inconsequential reasoning is so congenial with +the crude and inconsiderate notion generally entertained, of solid +mineral bodies having been formed by the infiltration of water into +the earth, that no opportunity should be lost of exposing an erroneous +manner of reasoning, which is employed in supporting a hypothesis +founded upon certain operations of the surface of this earth that cannot +be properly applied to the formation of mineral bodies. This object, +therefore, so far as it may come in the way, will be attended to in +this discussion, although I shall have another opportunity of farther +enlarging upon that subject. + +Our author begins by examining a geological operation, the very opposite +to that of mineral consolidation, and which would seem to have little +connection with the subject of this dissertation. In my theory, I +advanced two propositions with regard to the economy of this world: +First, That the solid masses of this earth, when exposed to the +atmosphere, decay, and are resolved into loose materials, of which the +vegetable soil upon the surface is in part composed; and, secondly, That +these loose materials are washed away by the currents of water, and +thus carried at last into the sea. Our author says "Here are two +suppositions, neither of which is grounded on facts;" and yet he has +but the moment before made the following confession: "That the soil, +however, receives an increase from some species of stones that moulder +by exposition to the air cannot be denied, but there is no proof that +all soil has arisen from decomposition."--Surely _all soil_, that +is made from the _hard and compact_ body of the land, which is my +proposition, must have arisen from _decomposition_; and I have no where +said, that _all_ the soil of this earth is made from the decomposition +or detritus of those stony substances; for, masses of looser sand and +softer substances contribute still more to the formation of vegetable +soils. + +With regard to the other proposition, our author says, "Soil is not +constantly carried away by the water, even from mountains."--I have not +said that it is _constantly_ washed away; for, while it is soil in which +plants grow, it is not travelling to the sea, although it be on the road, +and must there arrive in time. I have said, that it is _necessarily_ +washed away, that is, occasionally. M. de Luc's authority is then +referred to, as refuting this operation of water and time upon the soil. +Now, I cannot help here observing, that our author seems to have as +much misapprehended M. de Luc's argument as he has done mine. That +philosopher, in his letters to the Queen, has described most accurately +the decay of the rocks and solid mountains of the Alps and Jura, and the +travelling of their materials by water, although he does not carry them +to the sea. It is true, indeed, that this author, who supposes the +present earth on which we dwell very young, is anxious to make an earth, +_in time_, that shall not decay nor be washed away at all; but that time +is not come yet; therefore the authority, here given against my +theory, is the speculative supposition, or mere opinion, of a natural +philosopher, with regard to an event which may never come to pass, and +which I shall have occasion to consider fully in another place. + +Our author had just now said, that I have advanced two suppositions, +_neither of which is grounded on facts_: Now, with regard to the one, he +has acknowledged, that the mouldering of stones takes place, which is +the fact on which that proposition is grounded; and with regard to the +other, the only authority given against it is founded expressly upon +the moving of soil by means of the rain water, in order to make sloping +plains of mountains. Here, therefore, I have grounded my propositions +upon facts; and our author has founded his objections, first, upon a +difficulty which he has himself removed; and, secondly, upon nothing but +a visionary opinion, with regard to an earth which is not yet made, and +which, when once made, is never more to change. + +After making some unimportant observations,--of all water not flowing +into the sea,--and of the travelled materials being also deposited upon +the plains, etc. our author thus proceeds: "Hence the conclusion of our +author relative to the imperfect constitution of the globe falls to the +ground; and the pains he takes to learn, _by what means a decayed world +may be renovated_, are superfluous."--The object of my theory is +to show, that this decaying nature of the solid earth is the very +_perfection_ of its constitution, as a living world; therefore, it +was most proper that I should _take pains to learn_ by what means the +decayed parts might be renovated. It is true, indeed, that this will be +superfluous, when once that constitution of the earth, which M. de Luc +thinks is preparing, shall be finished; but, in the mean time, while +rivers carry the materials of our land, and while the sea impairs the +coast, I may be allowed to suppose that this is the actual constitution +of the earth. + +I cannot help here animadverting upon what seems to be our author's +plan, in making these objections, which have nothing to do with his +examination. He accuses me of giving this world a false or imperfect +constitution, (in which the solid land is considered as resolvable, and +the materials of that land as being washed away into the sea,) for no +other reason, that I can see, but because this may imply the formation +of a future earth, which he is not disposed to allow; and, he is now to +deny the stratified construction of this present earth to have been made +by the deposits of materials at the bottom of the sea, because that +would prove the existence of a former earth, which is repugnant to his +notion of the origin of things, and is contrary, as he says, to reason, +and the tenor of the Mosaic history. Let me observe, in passing, that M. +de Luc, of whose opinions our author expresses much approbation, thinks +that he proves, from the express words and tenor of the Mosaic history, +that the present earth was at the bottom of the sea not many years ago, +and that the former earth had then disappeared. + +But, what does our author propose to himself, in refusing to admit my +view of the operations which are daily transacting upon the surface of +this earth, where there is nothing dark or in the least mysterious, as +there may be in the mineral regions? Does he mean to say, that it is not +the purpose of this world to provide soil for plants to grow in? Does +he suppose that this soil is not moveable with the running water of the +surface? and, Does he think that it is not necessary to replace that +soil which is removed? This is all that I required in that constitution +of the world which he has thus attacked; and I wish that he or any +person would point out, in what respect I had demanded any thing +unreasonable, or any thing that is not actually to be observed every +day. + +Thus I have endeavoured to show, that our author has attacked my theory +in a part where I believe it must be thought invulnerable; but this is +only, I presume, in order that he may make an attack with more advantage +upon another part, viz. the composition of strata from the materials of +an earth thus worn out in the service of vegetation,--materials which +are necessarily removed in order to make way for that change of things +in which consists the active and living system of this world. If he +succeed in this attempt to refute my theory of the original formation +of strata, he would then doubtless find it more easy to persuade +philosophers that the means which I employ in bringing those materials +again to light, when transformed into such solid masses as the system of +this earth requires, are extravagant, unnatural, and unnecessary. Let us +then see how he sets about this undertaking. + +With regard to the composition of the earth, it is quoted from my +theory, that _the solid parts of the globe are in general composed +of sand, gravel, argillaceous and calcareous strata, or of various +compositions of these with other substances_; our author then adds, +"This certainly cannot be affirmed as a fact, but rather the contrary; +it holds only true of the surface, the basis of the greater part of +Scotland is evidently a granitic rock, to say nothing of the continents, +both of the Old and New World, according to the testimony of all +mineralogists." This proposition, with regard to the general composition +of the earth, I have certainly not assumed, I have maintained it as a +fact, after the most scrupulous examination of all that, with the most +diligent search, I have been able to see, and of all that authors +have wrote intelligibly upon the subject. If, therefore, I have so +misrepresented this great geological fact on which my theory is +absolutely founded, I must have erred with open eyes; and my theory +of the earth, like others which have gone before it, will, upon close +examination, appear to be unfounded, as the dissertation now before us +is endeavouring to represent it. + +Our author here, I think, alleges that the contrary to this, my +fundamental proposition, is the truth; and he has given us Scotland as +an example in which his assertion (founded upon the testimony of all +mineralogists), is illustrated. Now my geological proposition should +certainly be applicable to Scotland, which is the country that I ought +to be best acquainted with; consequently, if what our author here +asserts be true, I would have deserved that blame which he is willing to +throw on me. Let me then beg the readers attention for a moment, that I +may justify myself from that charge, and place in its proper light this +authority, upon so material a point in geology. + +I had examined Scotland from the one end to the other before I saw one +stone of granite in its native place, I have moreover examined almost +all England and Wales, (excepting Devonshire and Cornwall) without +seeing more of granite than one spot, not many hundred yards of extent; +this is at Chap; and I know, from information, that there is another +small spot in the middle of England where it is just seen. But, let me +be more particular with regard to Scotland, the example given in proof. + +I had travelled every road from the borders of Northumberland and +Westmoreland to Edinburgh; from Edinburgh, I had travelled to +Port-Patrick, and from that along the coast of Galloway and Airshire +to Inverary in Argyleshire, and I had examined every spot between the +Grampians and the Tweedale mountains from sea to sea, without seeing +granite in its place. I had also travelled from Edinburgh by Grief, +Rannock, Dalwhiny, Fort Augustus, Inverness, through east Ross and +Caithness, to the Pentland-Frith or Orkney islands, without seeing one +block of granite in its place. It is true, I met with it on my return +by the east coast, when I just saw it, and no more, at Peterhead and +Aberdeen; but that was all the granite I had ever seen when I wrote +my Theory of the Earth. I have, since that time, seen it in different +places; because I went on purpose to examine it, as I shall have +occasion to describe in the course of this work. + +I may now with some confidence affirm, from my own observation, and from +good information with regard to those places where I have not been, +except the northwest corner, I may affirm, I say, that instead of the +basis of the greatest part of Scotland being a granitic rock, which our +author has maintained as an evident thing, there is very little of it +that is so; not perhaps one five hundred part. So far also as I am to +judge from my knowledge of the mineral construction of England and +Wales, which I have examined with the greatest care, and from the +mineral chart which my friend Mr Watt made for me from his knowledge of +Cornwall, I would say that there is scarcely one five hundred part +of Britain that has granite for its basis. All the rest, except the +porphyry and basaltes, consists of stratified bodies, which are composed +more or less of the materials which I mentioned, generally, in the above +quotation, and which our author would dispute. + +But do not let me take the advantage of this error of our author with +regard to the mineralogy of Scotland, and thus draw what may be thought +an undue conclusion in favour of my general theory; let us go over and +examine the continent of Europe, and see if it is any otherwise there +than in Britain. From the granite of the Ural mountains, to that which +we find in the Pyrenees, there is no reason, so far as I have been able +to learn, to conclude that things are formed either upon any other +principle, or upon a different scale. But, instead of one five hundred +part, let us suppose there to be one fiftieth part of the earth in +general resting upon granite, I could not have expressed myself +otherwise than I have done; for, when I maintained that the earth in +general consisted of stratified bodies, I said that this was only _nine +tenths, or perhaps ninety-nine hundredths_ of the whole, and I mentioned +that there were other masses of a different origin, which should be +considered separately. Our author, on the contrary, asserts that the Old +and New Worlds, as well as Scotland, are placed upon granite as a basis, +which he says is according to the testimony of all mineralogists. +I shall have occasion to examine this opinion of mineralogists, in +comparing it with those masses of granite which appear to us; and I hope +fully to refute the geological, as well as mineralogical notions with +regard to that body. In the mean time, let me make the following +reflection, which here naturally occurs. + +My Theory of the Earth is here examined,--not with the system of +nature, or actual state of things, to which it certainly should have +corresponded,--but with the systematic views of a person, who has formed +his notions of geology from the vague opinion of others, and not from +what he has seen. Had the question been, How far my theory agreed with +other theories, our author might very properly have informed his readers +that it was diametrically opposite to the opinions of mineralogists; +but, this was no reason for concluding it to be erroneous; on the +contrary, it is rather a presumption that I may have corrected the error +of mineralogists who have gone before me, in like manner as it is most +reasonable to presume that our author may have corrected mine. Let us +then proceed to examine how far this shall appear to be the case. + +Our author has stated very fairly from the Theory, viz. _That all the +strata of the earth, not only those consisting of calcareous masses, but +others superincumbent on these, have had their origin at the bottom +of the sea, by the collection of sand, gravel, shells, coralline, and +crustaceous bodies, and of earths and clays variously mixed, separated, +and accumulated._ He then adds, "Various geological observations +contradict this conclusion. There are many stratified mountains of +argillaceous slate, gneiss, serpentine, jasper, and even marble, in +which either sand, gravel, shells, coralline, or crustaceous bodies are +never, or scarce ever found." + +Here our author seems to have deceived himself, by taking a very partial +view of things which should be fully examined, and well understood, +before general conclusions are to be drawn from those appearances; for, +although those particular objects may not be visible in the strata which +he has enumerated, or many others, they are found in those strata which +are either immediately connected and alternated with them, or with +similar strata; something to that purpose I think I have said; and, if +I had not, it certainly requires no deep penetration to have seen this +clear solution of that appearance of those objects not being found in +every particular stratum. He says that those marks of known materials +are never or scarce ever found;--by _scarce ever_ he surely means that +they are sometimes found; but if they shall only _once_ be found, his +argument is lost. I have not drawn my geological conclusion from every +particle in strata being distinguishable, but from there being certain +distinguishable particles in strata, and from our knowing what had been +the former state and circumstances of those distinguished parts. + +If every stone or part of a stratum, in which those known objects are +not immediately visible, must be considered as so _many geological +observations that contradict my theory_, (of strata being formed from +the materials of a former earth), then, surely every stone and every +stratum which visibly contains any of those materials, must prove my +theory. But if every stratum, where these are found in any part of it, +is to be concluded as having had its origin at the bottom of the sea; +and, if every concomitant stratum, though not having those objects +visible or sufficiently distinct, must be considered as having had the +same or a similar origin, that pretended contradiction of my theory +comes to no more than this, that every individual stone does not bear +in it the same or equal evidence of that general proposition which +necessarily results from the attentive consideration of the whole, +including every part. + +But to see how necessary it is to judge in this manner, not partially, +but upon the whole, we may observe, that there are two ways by which the +visible materials or distinguishable bodies of a former earth, not only +_may_ be rendered invisible in the composition of our present earth, +but _must_ be so upon many occasions. These are, _first_, by mechanical +comminution, which necessarily happens, more or less, in that operation +by which bodies are moved against one another, and thus transported from +the land to the bottom of the deepest seas; _secondly_, by chemical +operations, (whatever these may be, whether the action of water or of +fire, or both), which are also necessarily employed for consolidating +those loose materials, that are to form the rocks and stones of +this earth, and by means of which those materials are to have their +distinguishable shapes affected in all degrees and obliterated. +Therefore, to demand the visible appearance of those materials in every +stratum of the earth, or in every part of a stratum, is no other than to +misunderstand the subject altogether. The geological observations, +which have been thus alleged as contradicting my theory, are stratified +bodies, containing proofs of the general origin which I attribute to the +earth, but proofs which may not always be seen with equal facility as +those which even convince the vulgar. + +Our author has surely perplexed himself with what writers of late have +said concerning primitive mountains as they are called, a subject of +deeper search, than is commonly imagined, as I hope to show in the +course of this work. It is an interesting subject of investigation, +as giving us the actual view of those operations of nature which, in +forming my Theory of the Earth, more general principles had led me to +conclude _might be_. But, it is a subject which, I am afraid, will lead +me to give farther offence to our author, however innocent I may be in +giving nothing but what I have from nature. + +The reason for saying so is this; I am blamed for having endeavoured +to trace back the operations of this world to a remote period, by the +examination of that which actually appears, contrary, as is alleged, +"to reason, and the tenor of the Mosaic history, thus leading to an +abyss, from which human reason recoils, etc." In a word, (says our +author), "to make use of his own expression, _We find no vestige of +a beginning._ Then this system of successive worlds must have been +eternal." Such is the logic by which, I suppose, I am to be accused of +atheism. Our author might have added, that I have also said--_we see +no prospect of an end_; but what has all this to do with the idea of +eternity? Are we, with our ideas of _time_, (or mere succession), to +measure that of eternity, which never succeeded any thing, and which +will never be succeeded? Are we thus to measure eternity, that boundless +thought, with those physical notions of ours which necessarily limit +both space and time? and, because we see not the beginning of created +things, Are we to conclude that those things which we see have always +been, or been without a cause? Our author would thus, inadvertently +indeed, lead himself into that gulf of irreligion and absurdity into +which, he alleges, I have _boldly plunged_. + +In examining this present earth, we find that it must have had its +origin at the bottom of the sea, although our author seems willing to +deny that proposition. Farther, in examining the internal construction +of this stratified and sea-born mass, we find that it had been composed +of the moved materials of a former earth; and, from the most accurate +and extensive examination of those materials, which in many places are +indeed much disguised, we are led necessarily to conclude, that there +had been a world existing, and containing an animal, a vegetable, and a +mineral system. But, in thus tracing back the natural operations which +have succeeded each other, and mark to us the course of time past, we +come to a period in which we cannot see any farther. This, however, +is not the beginning of those operations which proceed in time and +according to the wise economy of this world; nor is it the establishing +of that, which, in the course of time, had no beginning; it is only the +limit of our retrospective view of those operations which have come to +pass in time, and have been conducted by supreme intelligence. + +My principal anxiety was to show how the constitution of this world +had been wisely contrived; and this I endeavoured to do, not from +supposition or conjecture, but from its answering so effectually the end +of its intention, viz. the preserving of animal life, which we cannot +doubt of being its purpose. Here then is a world that is not eternal, +but which has been the effect of wisdom or design. + +With regard again to the prospective view of the creation, How are we to +see the end of that wise system of things which so properly fulfils the +benevolent intention of its maker,--in giving sustenance to the animal +part, and information to intellectual beings, who, in these works of +nature, read what much concerns their peace of mind,--their intellectual +happiness? What then does our author mean, in condemning that +comprehensive view which I have endeavoured to take of nature? Would he +deny that there is to be perceived wisdom in the system of this world, +or that a philosopher, who looks into the operations of nature, may not +plainly read the power and wisdom of the Creator, without recoiling, as +he says, from the abyss? The abyss, from which a man of science should +recoil, is that of ignorance and error. + +I have thus shown, that, from not perceiving the wise disposition of +things upon the surface of this earth for the preservation of vegetable +bodies, our author has been led to deny the necessary waste of the +present earth, and the consequent preparation of materials for the +construction of another; I have also shown, that he denies the origin +which I had attributed to the stratified parts of this earth, as having +been the collection of moving materials from a former earth; and now +I am come to consider the professed purpose of this paper, viz. the +examination of solid stony substances which we find in those strata +of our earth, as well as in more irregular masses. Here, no doubt, my +theory would have been attacked with greater success, had our author +succeeded in pointing out its error with regard to the original +composition of those indurated bodies, to which I ascribe fusion as the +cause of their solidity. For, if we should, according to our author's +proposition, consider those consolidated bodies as having been +originally formed in that solid state, here the door might be shut +against any farther investigation;--But to what purpose?--Surely not to +refute my theory, but to explode every physical inquiry farther on the +subject, and thus to lead us back into the science of darkness and of +scepticism. But let us proceed to see our author's sentiments on this +subject. + +As I had proved from matter of fact, or the actual appearances of +nature, that all the strata of the earth had been formed at the bottom +of the sea, by the subsidence of those materials which either come from +the decaying land, or are formed in the sea itself, it was necessary +that I should consider in what manner those spongy or porous bodies of +loose materials, gathered together at the bottom of the sea, could have +acquired that consolidated state in which we find them, now that they +are brought up to our examination. Upon this occasion, our author says, +"The particles which now form the solid parts of the globe need not be +supposed to have originally been either spongy or porous, the interior +parts at the depth of a few miles might have been originally, as at +present, a solid mass." If, indeed, we shall make that supposition, we +may then save ourselves the trouble of considering either how the strata +of the earth have been formed or consolidated; for, they might have been +so originally. But, how can a naturalist who had ever seen a piece of +Derbyshire marble, or any other shell limestone, make that supposition? +Here are, to the satisfaction of every body of common understanding who +looks at them, bodies which are perfectly consolidated, bodies which +have evidently been formed at the bottom of the sea, and therefore which +were not originally a solid mass. Mr Bertrand, it is true, wrote a book +to prove that those appearances were nothing but a _lusus naturae_; and, +I suppose he meant, with our author, that those strata had been also +originally, as at present, a solid mass. + +With regard to the consolidation of strata, that cardinal point for +discussion, our author gives the following answer: "Abstracting from his +own gratuitous hypothesis, it is very easy to satisfy our author on this +head; the concreting and consolidating power in most cases arises from +the mutual attraction of the component particles of stones to each +other." This is an answer with regard to the _concreting power_, a +subject about which we certainly are not here inquiring. Our author, +indeed, has mentioned a _consolidating power_; but that is an improper +expression; we are here inquiring, How the interstices, between the +collected materials of strata, deposited at the bottom of the sea, have +been filled with a hard substance, instead of the fluid water which had +originally occupied those spaces. Our author then continues; "If these +particles leave any interstices, these are filled with water, which no +ways obstructs their solidity when the points of contact are numerous; +hence the decrepitation of many species of stones when heated." + +If I understand our author's argument, the particles of stone are, by +their mutual attractions, to leave those hard and solid bodies which +compose the strata, that is to say, those hard bodies are to dissolve +themselves; but, To what purpose? This must be to fill up the +interstices, which we must suppose occupied by the water. In that case, +we should find the original interstices filled with the substances which +had composed the strata, and we should find the water translated into +the places of those bodies; here would be properly a transmutation, but +no consolidation of the strata, such as we are here to look for, and +such as we actually find among those strata. It may be very easy for +our author to form those explanations of natural phenomena; it costs +no tedious observation of facts, which are to be gathered with labour, +patience, and attention; he has but to look into his own fancy, as +philosophers did in former times, when they saw the abhorrence of a +vacuum and explained the pump. It is thus that we are here told the +consolidation of strata _arises from the mutual attraction of the +component particles of stones to each other_; the power, by which the +particles of solid stony bodies retain their places in relation to each +other, and resist separation from the mass, may, no doubt, be properly +enough termed their mutual attractions; but we are not here inquiring +after that power; we are to investigate the power by which the particles +of hard and stony bodies had been separated, contrary to their mutual +attractions, in order to form new concretions, by being again brought +within the spheres of action in which their mutual attractions might +take place, and make them one solid body. Now, to say that this is by +their mutual attraction, is either to misunderstand the proper question, +or to give a most preposterous answer. + +It is not every one who is fit to reason with regard to abstract general +propositions; I will now, therefore, state a particular case, in +illustration of that proposition which has been here so improperly +answered. The strata of Derbyshire marbles were originally immense +collections at the bottom of the sea, of calcareous bodies consisting +almost wholly of various fragments of the _entrochi_; and they were then +covered with an indefinite number of other strata under which these +_entrochi_ must have been buried. In this original state of those +strata, I suppose the interstices between the fragments of the coralline +bodies to have been left full of sea-water; at present we find those +interstices completely filled with a most perfectly solid body of +marble; and the question is, whether that consolidating operation +has been the work of water and solution, by our naturalist's termed +infiltration; or if it has been performed, as I have maintained, by the +softening power or heat, or introduction of matter in the fluid state +of fusion. Our author does not propose any other method for the +consolidation of those loose and incoherent bodies, but he speaks of the +_mutual attraction of the component particles of stone to each other_; +Will that fill the interstices between the coralline bodies with solid +marble, as well as consolidate the coralline bodies themselves? or, if +it should, How are those interstices to be thus filled with a substance +perfectly different from the deposited bodies, which is also frequently +the case? But, how reason with a person who, with this consolidation of +strata, confounds the well known operation by which the mortar, made +with caustic lime and sand, becomes a hard body! One would imagine +that he were writing to people of the last age, and not to chemical +philosophers who know so well how that mortar is concreted. + +To my argument, That these porous strata are found _consolidated with +every different species of mineral substance_, our author makes the +following observation: "Here the difficulties to the supposition of an +aqueous solution are placed in the strongest light; yet it must be owned +that they partly arise from the author's own gratuitous supposition, +that strata existed at the bottom of the sea previous to their +consolidation;"--gratuitous supposition!--so far from being a +supposition of any kind, it is a self evident proposition; the terms +necessarily imply the conclusion. I beg the readers attention for a +moment to this part of our author's animadversion, before proceeding to +consider the whole; for, this is a point so essential in my theory, +that if it be a gratuitous supposition, as is here asserted, it would +certainly be in vain to attempt to build upon it the system of a world. + +That strata may exist, whether at the bottom of the sea, or any other +where, without being consolidated, will hardly be disputed; for, they +are actually found consolidated in every different degree. But, when +strata are found consolidated, at what time is it that we are to suppose +this event to have taken place, or this accident to have happened to +them?--Strata are formed at the bottom of water, by the subsidence or +successive deposits of certain materials; it could not therefore +be during their formation that such strata had been consolidated; +consequently, we must necessarily _conclude_, without any degree of +_supposition_, that _strata had existed at the bottom of the sea +previous to their consolidation_, unless our author can show how they +may have been consolidated previous to their existing. + +This then is what our author has termed a gratuitous supposition of +mine, and which, he adds, "is a circumstance which will not be allowed +by the patrons of the aqueous origin of stony substances, as we have +already seen."--I am perfectly at a loss to guess at what is here +alluded to _by having been already seen_, unless it be that which I have +already quoted, concerning things which have been never seen, that +is, _those interior parts of the earth which were originally a solid +mass_.--I have hardly patience to answer such reasoning;--a reasoning +which is not founded upon any principle, which holds up nothing +but chimera to our view, and which ends in nothing that is +intelligible;--but, others, perhaps, may see this dissertation of our +author's in a different light; therefore, it is my duty to analyse the +argument, however insignificant it may seem to me. + +I have minutely examined all the stratified bodies which I have been +able, during a lifetime, to procure, both in this country of Britain, +and from all the quarters of the globe; and the result of my inquiry has +been to conclude, that there is nothing among them in an original state, +as the reader will see in the preceding chapter. With regard again to +the masses which are not stratified, I have also given proof that they +are not in their original state, such as granite, porphyry, serpentine, +and basaltes; and I shall give farther satisfaction, I hope, upon that +head, in the course of this work. I have therefore concluded, That there +is nothing to be found in an original state, so far as we see, in the +construction of this earth. But, our author answers, That the interior +parts _might have been in an original state of solidity_.--So might +they have been upon the surface of the earth, or on the summits of our +mountains; but, we are not inquiring What they _might have been_, but +What they truly _are_. It is from this actual state in which the solid +parts of the earth are found, that I have endeavoured to trace back the +different states in which they must have been; and, by generalising +facts, I have formed a theory of the earth. If this be a wrong principle +or manner of proceeding in a physical investigation, or if, proceeding +upon that principle, I have made the induction by reasoning improperly +on any occasion, let this be corrected by philosophers, who may reason +more accurately upon the subject. But to oppose a physical investigation +with this proposition, _that things might have been otherwise_, is to +proceed upon a very different principle,--a principle which, instead of +tending to bring light out of darkness, is only calculated to extinguish +that light which we may have acquired. + +I shall afterwards have occasion to examine how far the philosophers, +who attribute to aqueous solution the origin of stony substances, have +proceeded in the same inductive manner of reasoning from effect to +cause, as they ought to do in physical subjects, and not by feigning +causes, or following a false analogy; in the mean time, I am to answer +the objections which have been made to the theory of the earth. + +In opposition to the theory of consolidating bodies by fusion, our +author has taken great pains to show, that I cannot provide materials +for such a fire as would be necessary, nor find the means to make it +burn had I those materials. Had our author read attentively my theory he +would have observed, that I give myself little or no trouble about that +fire, or take no charge with regard to the procuring of that power, as I +have not founded my theory on the _supposition_ of subterraneous +fire, however that fire properly follows as a conclusion from those +appearances on which the theory is founded. My theory is founded upon +the general appearances of mineral bodies, and upon this, that mineral +bodies must necessarily have been in a state of fusion. I do not pretend +to prove, demonstratively, that they had been even hot, however that +conclusion also naturally follows from their having been in fusion. It +is sufficient for me to demonstrate, That those bodies must have been, +more or less, in a state of softness and fluidity, without any species +of solution. I do not say that this fluidity had been without heat; +but, if that had been the case, it would have answered equally well the +purpose of my theory, so far as this went to explain the consolidation +of strata or mineral bodies, which, I still repeat, must have been +by simple fluidity, and not by any species of solution, or any other +solvent than that universal one which permeates all bodies, and which +makes them fluid. + +Our author has justly remarked the difficulty of fire burning below the +earth and sea. It is not my purpose here to endeavour to remove those +difficulties, which perhaps only exist in those suppositions which are +made on this occasion; my purpose is to show, that he had no immediate +concern with that question, in discussing the subject of the +consolidation which we actually find in the strata of the earth, unless +my theory, with regard to the igneous origin of stony substances, had +proceeded upon the supposition of a subterraneous fire. It is surely one +thing to employ fire and heat to melt mineral bodies, in supposing this +to be the cause of their consolidation, and another thing to acknowledge +fire or heat as having been exerted upon mineral bodies, when it is +clearly proved, from actual appearances, that those bodies had been in +a melted state, or that of simple fluidity. Here are distinctions which +would be thrown away upon the vulgar; but, to a man of science, who +analyses arguments, and reasons strictly from effect to cause, this is, +I believe, the proper way of coming at the truth. If the patrons of +the aqueous origin of stony substances can give us any manner of +scientifical, _i.e._ intelligible investigation of that process, it +shall be attended to with the most rigid impartiality, even by a patron +of the igneous origin of those substances, as he wishes above all things +to distinguish, in the mineral operations, those which, on the one hand, +had been the effect of water, from those which, on the other hand, had +been the immediate effect of fire or fusion;--this has been my greatest +study. But, while mineralists or geologists give us only mere opinions, +What is science profited by such inconsequential observations, as are +founded upon nothing but our vulgar notions? Is the figure of the +earth, _e.g._ to be doubted, because, according to the common notion of +mankind, the existence of an antipod is certainly to be denied? + +I am not avoiding to meet that question with regard to the providing +of materials for such a mineral fire as may be required; no question I +desire more to be asked to resolve; but it must not be in the manner +that our author has put that question. He has included this supposed +difficulty among a string of other arguments by which he would refute my +theory with regard to the igneous origin of stony substances, as if I +had made that fire a necessary condition or a principle in forming my +theory of consolidation. Now, it is precisely the reverse; and this is +what I beg that mineral philosophers will particularly attend to, and +not give themselves so much unnecessary trouble, and me so disagreeable +a talk. I have proved that those stony substances have been in the fluid +state of fusion; and from this, I have inferred the former existence of +an internal heat, a subterraneous fire, or a certain cause of fusion by +whatever name it shall be called, and by whatever means it shall have +been procured. The nature of that operation by which strata had been +consolidated, like that by which they had been composed, must, according +to my philosophy, be decided by ocular demonstration; from examining the +internal evidence which is to be found in those bodies as we see them in +the earth; because the consolidating operation is not performed in our +sight, no more than their stratification which our author has also +denied to have been made, as I have said, by the deposits of materials +at the bottom of the sea. Now, with regard to the means of procuring +subterraneous fire, if the consolidating operation shall be thus decided +to have been that of fusion, as I think I have fully shown, and for +which I have as many witnesses, perhaps as there are mineral bodies, +then our author's question, (how I am to procure a fire) in the way that +he has put it, as an argument against the fusion, would be at least +useless; for, though I should here confess my ignorance with regard to +the means of procuring fire, the evidence of the melting operation, or +former fluidity of those mineral bodies, would not be thereby in the +least diminished. If again no such evidence for the fusion of those +bodies shall appear, and it be concluded that they had been consolidated +by the action of water alone, as our author seems inclined to maintain, +he would have no occasion to start difficulties about the procuring of +fire, in order to refute a theory which then would fall of itself as +having no foundation. + +But in order to see this author's notion of the theory which he is here +examining, it may be proper to give a specimen of his reasoning upon +this subject of heat. He says, "That my supposition of heat necessary +for consolidating strata is _gratuitous_, not only because it is +unnecessary, as we have already shown, but also because it is +inconsistent with our author's own theory." Let us now consider those +two propositions. _First_, it is unnecessary, _as we have already +shown_;--I have already taken particular notice of what we have been +shown on this occasion, viz. That the earth at a certain depth _may +have been originally in a solid state_; and, that, where it is to be +consolidated, this is done by the _mutual attraction of the stony +particles_. Here is all that we have been shown to make subterraneous +heat, for the consolidation of strata, unnecessary; and now I humbly +submit, if this is sufficient evidence, that mineral heat is a +gratuitous supposition. + +Secondly, "_it is inconsistent with our author's own theory._" Here +I would beg the readers attention to the reasoning employed on +this occasion. He says, "according to him these strata, which were +consolidated by heat, were composed of materials gradually worn from a +preceding continent, casually and successively deposited in the sea; +Where then will he find, and how will he suppose, to have been formed +those enormous masses of sulphur, coal, or bitumen, necessary to produce +that immense heat necessary for the fusion of those vast mountains of +stone now existing? All the coal, sulphur, and bitumen, now known, does +not form the 100,000 part of the materials deposited within one quarter +of a mile under the surface of the earth; if, therefore, they were, as +his hypothesis demands, carried off and mixed with the other materials, +and not formed in vast and separate collections, they could never +occasion, by their combustion, a heat capable of producing the smallest +effect, much less those gigantic effects which he requires." + +Here is a comparative estimate formed between two things which have not +any necessary relation; these are, the quantity of combustible materials +found in the earth, on the one hand, and the quantity which is supposed +necessary for hardening and consolidating strata, on the other. If this +earth has been consolidated by the burning of combustible materials, +there must have been a superfluity, so far as there is a certain +quantity of these actually found unconsumed in the strata of the earth. +Our author's conclusion is the very opposite; let us then see how he +is to form his argument, by which he proves that the supposition of +subterraneous heat for hardening bodies is gratuitous and unnecessary, +as being inconsistent with my theory. + +According to my theory, the strata of this earth are composed of the +materials which came from a former earth; particularly these combustible +strata that contain plants which must have grown upon the land. Let +us then suppose the subterraneous fire supplied with its combustible +materials from this source, the vegetable bodies growing upon the +surface of the land. Here is a source provided for the supplying of +mineral fire, a source which is inexhaustible or unlimited, unless +we are to circumscribe it with regard to time, and the necessary +ingredients; such as the matter of light, carbonic matter, and the +hydrogenous principle. But it is not upon any deficiency of this kind +that our author founds his estimate; it is upon the superfluity of +combustible materials which is actually found in this earth, after it +had been properly consolidated and raised above the surface of the sea. +This is a method of reasoning calculated to convince only those who do +not understand it; it is as if we should conclude that a person had died +of want, because he had left provision behind him. Our author certainly +means to employ nothing but the combustible minerals of the present +earth, in feeding the subterraneous fire which is to concoct a future +earth; in that case, I will allow that his provision is deficient; but +this is not my theory. + +I am not here to enter into any argument concerning subterraneous +fire; the reader will find, in the foregoing theory, my reasons for +concluding, That subterraneous fire had existed previous to, and ever +since, the formation of this earth,--that it exists in all its vigour +at this day,--that there is, in the constitution of this earth, a +superfluity of subterranean heat,--and that there is wisely provided a +proper remedy against any destructive effect to the system, that might +arise from that superabundant provision of this necessary agent. Had our +author attended to the ocular proof that we have of the actual existence +of subterraneous fire, and to the physical demonstrations which I have +given of the effects of heat in melting mineral bodies, he must have +seen that those arguments of his, with regard to the difficulty or +impossibility of procuring that fire, can only show the error of his +reasoning. I am far from supposing that my theory may be free from +inconsistency or error; I am only maintaining that, in all his confident +assertions, this author has not hitherto pointed any of these out. + +So far I have answered our author's objections as to consolidation, and +I have given a specimen of his reasoning upon that subject; but with +regard to my Theory of the Earth, although simple fluidity, without +heat, would have answered the purpose of consolidating strata that had +been formed at the bottom of the sea, it was necessary to provide a +power for raising those consolidated strata from that low place to the +summits of the continents; now, in supposing heat to be the cause of +that fluidity which had been employed in the consolidation of those +submarine masses, we find a power capable of erecting continents, and +the only power, so far as I see, which natural philosophy can employ +for that purpose. Thus I was led, from the consolidation of strata, to +understand the nature of the elevating power, and, from the nature of +that power, again to understand the cause of fluidity by which the rocks +and stones of this earth had been consolidated. + +Having thus, without employing the evidence of any fire or _burning_, +been necessarily led to conclude an extreme degree of heat exerted in +the mineral regions, I next inquire how far there are any appearances +from whence we might conclude whether that active subterraneous power +still subsists, and what may be the nature of that power. When first I +conceived my theory, naturalists were far from suspecting that basaltic +rocks were of volcanic origin; I could not then have employed an +argument from these rocks as I may do now, for proving that the fires, +which we see almost daily issuing with such force from volcanos, are a +continuation of that active cause which has so evidently been exerted +in all times, and in all places, so far as have been examined of this +earth. + +With regard to the degree of heat in that subterraneous fire, our +author, after proving that combustible materials would not burn in the +mineral regions, then says, that suppose they were to burn, this would +be "incapable of forming a heat even equal to that of our common +furnaces, as Mr Dolomieu has clearly shown to be the case with respect +to volcanic heat." The place to which he alludes, I believe to be that +which I have quoted from the Journal de Physique (Part I. page 139) to +which I here beg leave to refer the reader. After what I have already +said, this subject will appear to be of little concern to me; but, it +must be considered, that my object, in these answers, is not so much to +justify the theory which I have given, as it is to remove that prejudice +which, to those who are not master of chemical and mineral subjects, +will naturally arise from the opinion or authority of a scientific man, +and a chemist; therefore, I think it my business to show how much he +has misconceived the matter which he treats of, and how much he +misunderstands the subject of my theory. + +Mr Dolomieu alleges that the volcanic fire operates in the melting of +bodies, not by the intensity of its heat, which is the means employed by +us in our operations, but in the long continuance of its action. But in +that proposition, this philosopher is merely giving us his opinion; and, +this opinion our author mistakes, I suppose, for the fact on which that +opinion had been (perhaps reasonably) founded. The reader will see, in +the place quoted, or in the _avant-propos_ to his _Memoire sur les Iles +Ponces_, the fact to be this; That the Chevalier Dolomieu finds those +bodies which we either cannot melt in our fires, or which we cannot melt +without changing them by calcination and vitrification, he finds, I say, +these substances had actually been melted with his lavas; he also finds +those substances, which are necessarily dissipated in our fires, to have +been retained in those melted mineral substances. Had our author quoted +the text, instead of giving us his own interpretation, he could not have +offered a stronger confirmation of my theory; which certainly is not +concerned with the particular intensity of volcanic fire, and far less +with what may be the opinion of any naturalist with regard to that +intensity, but only with the efficacy of that volcanic heat for the +melting of mineral substances. Now this efficacy of volcanic fire, so +far as we are to found upon the authority given on this occasion, is +clearly confirmed by the observations of a most intelligent mineralist, +and one who is actually a patron of the opposite theory to that which I +have given. This being the state of the case, Must I not conclude, that +our author has misunderstood the subject, and that he has been led to +give a mutilated opinion of Mr Dolomieu, in order to refute my theory, +when either the entire opinion, or the facts on which the opinion had +been founded, would have confirmed it? + +I have thus endeavoured to put in its true light a species of reasoning, +which, while it assumes the air and form of that inductive train of +thought employed by men of science for the investigation of nature, is +only fit to mislead the unwary, and, when closely examined, will appear +to be inconsequential or unfounded. How mortifying then to find, that +one may be employed almost a lifetime in generalising the phenomena of +nature, or in gathering an infinity of evidence for the forming of a +theory, and that the consequence of this shall only be to give offence, +and to receive reproach from those who see not things in the same +light!--While man has to learn, mankind must have different opinions. +It is the prerogative of man to form opinions; these indeed are often, +commonly I may say, erroneous; but they are commonly corrected, and it +is thus that truth in general is made to appear. + +I wrote a general Theory for the inspection of philosophers, who +doubtless will point out its errors; but this requires the study of +nature, which is not the work of a day; and, in this political age, the +study of nature seems to be but little pursued by our philosophers. In +the mean time, there are, on the one hand, sceptical philosophers, who +think there is nothing certain in nature, because there is misconception +in the mind of man; on the other hand, there are many credulous +amateurs, who go to nature to be entertained as we go to see a +pantomime: But there are also superficial reasoning men, who think +themselves qualified to write on subjects on which they may have read +in books,--subjects which they may have seen in cabinets, and which, +perhaps, they have just learned to name; without truly knowing what they +see, they think they know those regions of the earth which never can be +seen; and they judge of the great operations of the mineral kingdom, +from having kindled a fire, and looked into the bottom of a little +crucible. + +In the Theory of the Earth which was published, I was anxious to warn +the reader against the notion that subterraneous heat and fusion could +be compared with that which we induce by our chemical operations +on mineral substances here upon the surface of the earth; yet, +notwithstanding all the precaution I had taken, our author has bestowed +four quarto pages in proving to me, that our fires have an effect upon +mineral substances different from that of the subterraneous power which +I would employ. + +He then sets about combining metals with sulphur in the moist way, as if +that were any more to his purpose than is the making of a stalactite for +the explanation of marble. Silver and lead may be sulphurated, as he +says, with hepatic gas; but, Has the sulphurated solid ores of those +metals, and that of iron, been formed in the moist way, as in some +measure they may be by the fusion of our fires? But, even suppose that +this were the case, Could that explain a thousand other appearances +which are inconsistent with the operation of water? We see aerated lead +dissolved in the excavations of our mines, and again concreted by the +separation of the evaporated solvent, in like manner as stalactical +concretions are made of calcareous earth; but, so far from explaining +mineral appearances, as having had their concretions formed in the same +manner, here is the most convincing argument against it; for, among the +infinite variety of mineral productions which we find in nature, Why +does no other example of aqueous concretion ever occur upon the surface +of the earth except those which we understand so well, and which we +therefore know cannot be performed in the bodies of strata not exposed +to the evaporation of the solvent, a circumstance which is necessary. + +I have given a very remarkable example of mineral fusion, in reguline +manganese, (as the reader will see in page 68.) It is not that this +example is more to the purpose of my theory than what may be found in +every species of stone; but this example speaks so immediately to +the common sense of mankind, (who are often convinced by a general +resemblance of things, when they may not see the force of demonstration +from an abstract principle) that I thought it deserved a place on that +account, as well as being a curious example, But more particularly to my +antagonist, who has been pleased (very improperly indeed) to try some +part of my theory in the fire, here is an example which should have +been absolutely in point, and without any manner of exception:--Has he +acknowledged this?--No; he has, on the contrary, endeavoured to set this +very example aside. + +On this occasion, he says, "Manganese has been found in a reguline state +by M. de la Peyrouse, and in small grains, as when produced by fire. +True; but it was mixed with a large quantity of iron, which is often, +found in that form without any suspicion of fusion. A fire capable of +melting quartz might surely produce it in larger masses." We have here +a kind of two arguments, for removing the effect of this example; and I +shall consider them separately. + +The first of these is, the not being suspected of having been in fusion; +now, if this were to be admitted as an argument against the igneous +origin of stony substances, it might have superseded the adducing of any +other, for it is applicable perhaps to every mineral; but we must here +examine the case more minutely. + +This argument, of the manganese being in a mine of iron, if I understand +it rightly, amounts to this, that, as iron ore is not suspected of +having been melted, therefore, we should doubt the manganese having been +so. If this be our author's meaning, it is not the fair conclusion which +the case admits of; for, so far as the manganese appears evidently to +have been in a melted state, the iron ore should be _suspected_ of +having been also in fusion, were there no other evidence of that fact. +In science, however, it is not suspicion that should be employed in +physical investigation; the question at present is; If the phenomena of +the case correspond to the conclusion which the intelligent mineralist, +who examined them, has formed? and, to this question, our author gives +no direct answer. He says, _iron is often found in that form without any +suspicion of fusion_. This is what I am now to answer. + +The form in which the manganese appears is one of the strongest proofs +of those masses having been in fusion; and, if iron should ever be found +in that form, it must give the same proof of mineral fusion as this +example of manganese; let us then see the nature of this evidence. The +form of the manganese is that of a fluid body collecting itself into a +spherical figure by the cohesion or attraction of its particles, so far +as may be admitted by other circumstances; but, being here refilled by +the solid part on which it rests, this spherical body is flattened by +the gravitation of its substance. Now here is a regular form, which +demonstrates the masses to have been in the state of fusion; for, there +is no other way in which that form of those reguline masses could have +been induced. + +There now remains to be considered what our author has observed +respecting the intensity of the fire and size of the masses. "A +fire capable of melting quartz might surely produce it (meaning the +manganese) in larger masses." M. de la Peyrouse says, that those masses +were in all respects as if formed by art, only much larger, as the +powers of nature exceed those of our laboratories. What then is it that +is here meant to be disputed? We are comparing the operation of nature +and that of art, and these are to be judged of by the product which we +examine; but the quantity, in this case, or the size of the masses, +makes no part of the evidence, and therefore is here most improperly +mentioned by our author. With regard again to the nature of the fire by +which the fusion had been produced, he is much mistaken if he imagines +that the reduction of the reguline or metallic manganese depends upon +the intensity of the heat; it depends upon circumstances proper for the +separation of the oxygenating principle from the calx, in like manner as +the calcination of calcareous spar must depend upon circumstances proper +for allowing the separation of the carbonic acid or fixed air. + +But do not let us lose sight of our proper subject, by examining things +foreign or not so immediately to the purpose. We are only inquiring if +those flattened spheres of native manganese had been formed by water, or +if it were by fusion; for, our author agrees that there is no other way. +Why then does he endeavour to evade giving a direct answer, and fly away +to consider the quantity of the product, as if that had any thing to do +with, the question, or as if that quantity were not sufficient, neither +of which is the case. In short, our author's whole observation, on this +occasion, looks as if he were willing to destroy, by insinuation, the +force of an argument which proves the theory of mineral fusion; and that +he wishes to render doubtful, by a species of sophistry, what in fair +reasoning he cannot deny. + +Our author has written upon the subject of phlogiston; one would suppose +that he should be well acquainted with inflammable bodies at least; let +us see then what he has to observe upon that subject. He quotes from +my Theory, that spar, quartz, pyrites, crystallised upon or near each +other, and adhering to coal, or mixed with bitumen, etc. are found; +circumstances that cannot be explained in the hypothesis of solution +in the moist way.--He then answers;--"Not exactly, nor with certainty; +which is not wonderful: But they are still less explicable in the +hypothesis of dry solution, as must be apparent from what has been +already said. How coal, an infusible substance, could be spread into +strata by mere heat, is to me incomprehensible."--It is only upon the +last sentence that I am here to remark: This, I believe, will be a +sufficient specimen of our author's understanding, with regard at least +to my Theory which he is here examining. + +The reader will see what I have said upon the subject of coal, by +turning back to the second section of the preceding chapter. I had given +almost three quarto pages upon that subject, endeavouring to explain how +all the different degrees of _infusibility_ were produced, by means of +heat and distillation, in strata which had been originally more or less +oily, bituminous, and _fusible_; and now our author says, that it is +incomprehensible to him, how coal, _an infusible substance_, could be +spread into strata by mere heat.--So it truly may, either to him or to +any other person; but, it appears to me almost as incomprehensible, how +a person of common understanding should read my Dissertation, and impute +to it a thing so contrary to its doctrine. + +Nothing can better illustrate the misconceived view that our author +seems to have taken of the two opposite theories, (_i. e_. of +consolidation by means of heat, and by means of water alone,) than +his observation upon the case of mineral alkali. To that irrefragable +argument (which Dr Black suggested) in proof of this substance having +been in a state of fusion in the mineral regions, our author makes the +following reply; "What then will our author say of the vast masses +of this salt which are found with their full quantity of water of +crystallization?"--There is in this proposition, insignificant as it may +seem, a confusion of ideas, which it certainly cannot be thought worth +while to investigate; but, so far as the doctrine of the aqueous theory +may be considered as here concerned, it will be proper that I should +give some answer to the question so triumphantly put to me. + +Our author is in a mistake in supposing that Dr Black had written any +thing upon the subject; he had only suggested the argument of this +example of mineral alkali to me, as I have mentioned; and, the use I +made of that argument was to corroborate the example I had given of sal +gem. If, therefore, our author does not deny the inference from the +state of that mineral alkali, his observation upon it must refer to +something which this other example of his is to prove on the opposite +side, or to support the aqueous instead of the igneous theory; and, this +is a subject which I am always willing to examine in the most impartial +manner, having a desire to know the true effect of aqueous solution in +the consolidation of mineral bodies, and having no objection to allow it +any thing which it can possibly produce, although denying that it can do +every thing, as many mineralists seem to think. + +The question, with regard to this example of our author's of a mineral +alkali with its water of crystallization, must be this, Whether those +saline bodies had been concreted by the evaporation of the aqueous +solvent with which they had been introduced, or by the congelation of +that saline substance from a fluid state of fusion; for, surely, we are +not to suppose those bodies to have been created in the place and state +in which we find them. With regard to the evaporation or separation +of the aqueous solvent, this may be easily conceived according to the +igneous theory; but, the aqueous theory has not any means for the +producing of that effect in the mineral regions, which is the only place +we are here concerned with. Therefore, this example of a concreted body +of salt, whatever it may prove in other respects, can neither diminish +the evidence of my Theory with regard to the igneous origin of stony +substances, nor can it contribute to support the opposite supposition of +an aqueous origin to them. + +But to show how little reason our author had for exulting in that +question which he so confidently proposed in order to defeat my +argument, let us consider this matter a little farther. I will for a +moment allow the aqueous theory to have the means for separating +the water from the saline solution, and thus to concrete the saline +substance in the bowels of the earth; this concretion then is to be +examined with a view to investigate the last state of this body, which +is to inform us with regard to those mineral operations. But, our author +has not mentioned whether those masses appear to have been crystallised +from the aqueous solution, or if they appear to have been congealed from +the melted state of their _aqueous fusion_.--Has he ever thought of +this? Now this is so material a point in the view with which that +example has been held out to us, that, without showing that this salt +had crystallised from the solution, he has no right to employ it as an +example; and if, on the other hand, it should appear to have simply +congealed from the state of aqueous fusion, then, instead of answering +the purpose for which our author gave it, it would refute his +supposition, as certainly as the example which I have given. + +So far I have reasoned upon the supposition of this alkali, with its +water of crystallization, being truly a mineral concretion; but, I see +no authority for such a supposition: It certainly may be otherwise; +and, in that case, our author would have no more right to give it as an +example in opposition to Dr Black's argument, than he would have to give +the crystallization of sea-salt, on Turk's Island, in opposition to the +example which I had given, of the salt rock, at Northwych in Cheshire, +having been in the state of fusion. + +It certainly was incumbent on our author to have informed us, if those +masses of salt were found in, what may be properly termed, their mineral +state; or, if the state in which they are found at present had been +produced by the influences of the atmosphere, transforming that saline +substance from its mineral state, as happens upon so many other +occasions; I am inclined to suspect that this last is truly the case. +It may be thought illiberal in me to suppose a natural philosopher thus +holding out an example that could only serve to lead us into error, or +to mislead our judgment with regard to those two theories which is the +subject of consideration. This certainly would be the case, almost +on any other occasion; but, when I find every argument and example, +employed in this dissertation, to be either unfounded or misjudged, +Whether am I to conclude our author, on this occasion, to be consistent +with himself, or not? + +I have but one article more to observe upon. I had given, as I thought, +a kind of demonstration, from the internal evidence of the stone, that +granite had been in the fluid state of fusion, and had concreted by +crystallization and congelation from that melted state. This no doubt +must be a stumbling block to those who maintain that granite mountains +are the primitive parts of our earth; and who, like our author, suppose +that "things may have been originally, as at present, in a solid state." +It must also be a great, if not an invincible obstacle in the way of the +aqueous theory, which thus endeavours to explain those granite veins +that are found traversing strata, and therefore necessarily of a +posterior formation. + +To remove that obstacle in the way of the aqueous theory, or to carry +that theory over the obstacle which he cannot remove, our author +undertakes to refute my theory with regard to the igneous origin of +stony substances, by giving an example of granite formed upon the +surface of the earth by means of water, or in what is called the +moist way; and he closes his Dissertation with this example as an +_experimentum crucis_. It is therefore necessary that I take this +demonstration of our author into particular consideration; for, surely, +independent of our controversy, which is perhaps of little moment, here +is the most interesting experiment, as it is announced, that mineralogy +could be enriched with. + +"To close this controversy," says our author, "I shall only add, +that granite, recently formed in the moist way, has been frequently +found."--Of that remarkable event, however, he has selected only one +example. This is to be found upon the Oder; and the authority upon which +our author has given it, is that of Lasius Hartz. + +The formation of a granite stone, from granite sand, by means of water, +is inconsistent with our chemical knowledge of those mineral substances +which constitute that stone; it is repugnant to the phenomena which +appear from the inspection of the natural bodies of this kind; and it +is directly contrary to the universal experience in granite countries, +where, instead of any thing concreting, every thing is going into +decay, from the loose stones and sand of granite, to the solid rock and +mountains which are always in a state of degradation. Therefore, to have +any credit given to such a story, would require the most scientific +evidence in its favour. Now, in order that others may judge whether this +has been the case in this example, I will transcribe what our author has +said upon the subject; and then I will give the view in which it appears +to me. + +He says, "a mole having been constructed in the Oder in the year 1723, +350 feet long, 54 feet in height, 144 feet broad at bottom, and 54 at +the top, its sides only were granite, without any other cement than +moss; the middle space was entirely filled with granite sand. In a short +time this concreted into a substance so compact as to be impenetrable by +water."--Here is an example, according to our author, of _granite formed +in the moist way_. But now, I must ask to see the evidence of that fact; +for, from what our author has told us, I do not even see reason to +conclude that there was the least concretion, or any stone formed at +all. A body of sand will be _so compacted as to be impenetrable by +water_, with the introduction of a very little mud, and without any +degree of concretion; muddy water, indeed, cannot be made to pass +through such a body without compacting it so; and this every body finds, +to their cost, who have attempted to make a filter of that kind. + +But I shall suppose Lasius has informed our author that there had been +a petrifaction in this case; and, before I admit this example of the +formation of granite, I must ask what sort of a granite it was;--whether +of two, three, or four ingredients; and, how these were disposed. If, +again, it were not properly a granite, but a stone formed of granite +sand, What is the cementing substance?--Is it quartz, felt-spar, mica, +or schorl?--or, Was it calcareous? If our author knows any thing about +these necessary questions, Why has he not informed us, as minutely as +he has done with regard to the dimensions of the mole, with which we +certainly are less concerned? If, again, he knows no more about the +matter than what he has informed us of, he must have strangely imposed +upon himself, to suppose that he was giving us an example of the +_formation of granite in the moist way_, when he has only described an +effectual way of retaining water, by means of sand and mud. + + + +CHAP. III. + +Of Physical Systems, and Geological Theories, in general. + +In the first chapter I have given a general theory of the earth, +with such proofs as I thought were sufficient for the information of +intelligent men, who might satisfy themselves by examining the facts on +which the reasoning in that theory had been founded. + +In the second chapter, I have endeavoured to remove the objections which +have been made to that theory, by a strenuous patron of the commonly +received opinion of mineralogists and geologists,--an opinion which, if +not diametrically opposite, differs essentially from mine. But now I am +to examine nature more particularly, in order to compare those different +opinions with the actual state of things, on which every physical theory +must be founded. Therefore, the opinions of other geologists should be +clearly stated, that so a fair comparison may be made of theories which +are to represent the system of this earth. + +Now, if I am to compare that which I have given as a theory of the +earth, with the theories given by others under that denomination, I +find so little similarity, in the things to be compared, that no other +judgment could hence be formed, perhaps, than that they had little or no +resemblance. I see certain treatises named Theories of the Earth; but, I +find not any thing that entitles them to be considered as such, unless +it be their endeavouring to explain certain appearances which are +observed in the earth. That a proper theory of the earth should explain +all those appearances is true; but, it does not hold, conversely, that +the explanation of an appearance should constitute a theory of the +earth. So far as the theory of the earth shall be considered as the +philosophy or physical knowledge of this world, that is to say, a +general view of the means by which the end or purpose is attained, +nothing can be properly esteemed such a theory unless it lead, in some +degree, to the forming of that general view of things. But now, let us +see what we have to examine in that respect. + +We have, first, Burnet's Theory of the Earth. This surely cannot be +considered in any other light than as a dream, formed upon the poetic +fiction of a golden age, and that of iron which had succeeded it; at the +same time, there are certain appearances in the earth which would, in a +partial view of things, seem to justify that imagination. In Telliamed, +again, we have a very ingenious theory, with regard to the production of +the earth above the surface of the sea, and of the origin of those +land animals which now inhabit that earth. This is a theory which has +something in it like a regular system, such as we might expect to find +in nature; but, it is only a physical romance, and cannot be considered +in a serious view, although apparently better founded than most of that +which has been wrote upon the subject. + +We have then a theory of a very different kind; this is that of the +Count de Buffon. Here is a theory, not founded on any regular system, +but upon an irregularity of nature, or an accident supposed to have +happened to the sun. But, are we to consider as a theory of the earth, +an accident by which a planetary body had been made to increase the +number of these in the solar system? The circumvolution of a planetary +body (allowing it to have happened in that manner) cannot form the +system of a world, such as our earth exhibits; and, in forming a theory +of the earth, it is required to see the aptitude of every part of this +complicated machine to fulfil the purpose of its intention, and not to +suppose the wise system of this world to have arisen from, the cooling +of a lump of melted matter which had belonged to another body. When +we consider the power and wisdom that must have been exerted in the +contriving, creating, and maintaining this living world which sustains +such a variety of plants and animals, the revolution of a mass of dead +matter according to the laws of projectiles, although in perfect wisdom, +is but like a unite among an infinite series of ascending numbers. + +After the theory of that eloquent writer, founded on a mere accident, or +rather the error of a comet which produced the beautiful system of this +world, M. de Luc, in his Theory of the earth, has given us the history +of a disaster which befell this well contrived world;--a disaster which +caused the general deluge, and which, without a miracle, must have +undone a system of living beings that are so well adapted to the present +state of things. But, surely, general deluges form no part of the theory +of the earth; for, the purpose of this earth is evidently to maintain +vegetable and animal life, and not to destroy them. + +Besides these imaginary great operations in the natural history of this +earth, we have also certain suppositions of geologists and mineralists +with regard to the effect of water, for explaining to us the +consolidation of the loose materials of which the strata of the earth +had been composed, and also for producing every other appearance, or any +which shall happen to occur in the examination of the earth, and require +to be explained. That this is no exaggerated representation, and +that this is all we have as a theory, in the suppositions of those +geologists, will appear from the following state of the case. + +They suppose water the agent employed in forming the solid bodies of the +earth, and in producing those crystallised bodies which appear in +the mineral kingdom. That this is a mere supposition will appear by +considering; first, that they do not know how this agent water is to +operate in producing those effects; nor have they any direct proof +of the fact which is alleged, from a very fallaceous analogy; and, +secondly, that they cannot tell us where this operation is to be +performed. They cannot say that it is in the earth above the level of +the sea: for, the same appearances are found as deep as we can examine +below that level; besides, we see that water has the opposite effect +upon the surface of the earth, through which it percolates dissolving +soluble substances, and thus resolving solid bodies in preparing soil +for plants. If, again, it be below the level of the sea, that strata of +the earth are supposed to be consolidated by the infiltration of that +water which falls from the heavens; this cannot be allowed, so far as +whatever of the earth is bibulous, in that place, must have been always +full of water, consequently cannot admit of that supposed infiltration. + +But allowing those suppositions to be true, there is nothing in them +like a theory of the earth,--a theory that should bring the operations +of the world into the regularity of ends and means, and, by generalizing +these regular events, show us the operation of perfect intelligence +forming a design; they are only an attempt to show how certain things, +which we see, have happened without any perceivable design, or without +any farther design than this particular effect which we perceive. If we +believe that there is almighty power, and supreme wisdom employed for +sustaining that beautiful system of plants and animals which is so +interesting to us, we must certainly conclude, that the earth, on which +this system of living things depends, has been constructed on principles +that are adequate to the end proposed, and procure it a perfection which +it is our business to explore. Therefore, a proper system of the earth +should lead us to see that wise contraction, by which this earth is made +to answer the purpose of its intention and to preserve itself from every +accident by which the design of this living world might be frustrated as +this world is an active scene, or a material machine moving in all its +parts, we must see how this machine is so contrived, as either to have +those parts to move without wearing and decay, or to have those parts, +which are wasting and decaying, again repaired. + +A rock or stone is not a subject that, of itself, may interest a +philosopher to study; but, when he comes to see the necessity of those +hard bodies, in the constitution of this earth, or for the permanency +of the land on which we dwell, and when he finds that there are means +wisely provided for the renovation of this necessary decaying part, as +well as that of every other, he then, with pleasure, contemplates this +manifestation of design, and thus connects the mineral system of +this earth with that by which the heavenly bodies are made to move +perpetually in their orbits. It is not, therefore, simply by seeing the +concretion of mineral bodies that a philosopher is to be gratified in +his his intellectual pursuit, but by the contemplation of that system in +which the necessary resolution of this earth, while at present it serves +the purpose of vegetation, or the fertility of our soil, is the very +means employed in furnishing the materials of future land. + +It is such a view as this that I have endeavoured to represent in the +theory which I have given. I have there stated the present situation of +things, by which we are led to perceive a former state; and, from that +necessary progress of actual things, I have concluded a certain system +according to which things will be changed, without any accident or +error. It is by tracing this regular system in nature that a philosopher +is to perceive the wisdom with which this world has been contrived; but, +he must see that wisdom founded upon the aptitude of all the parts to +fulfil the intention of the design; and that intention is to be deduced +from the end which is known to be attained. Thus we are first to reason +from effect to cause, in seeing the order of that which has already +happened; and then, from those known causes, to reason forwards, so as +to conceive that which is to come to pass in time. Such would be the +philosophy of this earth, formed by the highest generalisation +of phenomena, a generalisation which had required the particular +investigation of inductive reasoning. + +That no such theory as this, founded upon water as an agent operating in +the changes of this earth, has yet appeared, will, I believe be easily +allowed. With regard again to fire as an agent in the mineral operations +of this earth, geologists have formed no consistent theory. They see +volcanoes in all the quarters of the globe, and from those burning +mountains, they conjecture other mountains have been formed. But a +burning mountain is only a matter of fact; and, they have not on this +formed any general principle, for establishing what may be called a +theory of the earth. Those who have considered subterraneous fires as +producing certain effects, neither know how these have been procured, +nor do they see the proper purpose for which they are employed in the +system of this world. In this case, the agent fire is only seen as +a destructive element, in like manner as deluges of water have been +attributed by others to changes which have happened in the natural state +of things. These operations are seen only as the accidents of nature, +and not as part of that design by which the earth, which is necessarily +wasted in the operations of the world, is to be repaired. + +So far from employing heat or subterraneous fire as an agent in the +mineral operations of the earth, the volcanic philosophers do not +even attempt to explain upon that principle the frequent nodules of +calcareous, zeolite, and other spatose and agaty substances, in those +basaltic bodies which they consider as lavas. Instead then of learning +to see the operation of heat as a general principle of mineral +consolidation and crystallization, the volcanic philosophers endeavour +to explain those particular appearances, which they think inconsistent +with fusion, by aqueous infiltration, no otherwise than other +mineralists who do not admit the igneous origin of those basaltic +bodies. Thus, that great agent, subterraneous heat, has never been +employed by geologists, as a general principle in the theory of the +earth; it has been only considered as an occasional circumstance, or as +the accident of having certain mineral bodies, which are inflammable, +kindled in the earth, without so much as seeing how that may be done. + +This agent heat, then, is a new principle to be employed in forming a +theory of the earth; a principle that must have been in the constitution +of this globe, when contrived to subsist as a world, and to maintain +a system of living bodies perpetuating their species. It is therefore +necessary to connect this great mineral principle, subterraneous fire +or heat, with the other operations of the world, in forming a general +theory. For, whether we are to consider those great and constant +explosions of mineral fire as a principal agent in the design, or only +as a casual event depending upon circumstances which give occasion to an +operation of such magnitude, here is an object that must surely have its +place in every general theory of the earth. + +In examining things which actually exist, and which have proceeded in a +certain order, it is natural to look for that which had been first; man +desires to know what had been the beginning of those things which now +appear. But when, in forming a theory of the earth, a geologist shall +indulge his fancy in framing, without evidence, that which had preceded +the present order of things, he then either misleads himself, or writes +a fable for the amusement of his reader. A theory of the earth, which +has for object truth, can have no retrospect to that which had preceded +the present order of this world; for, this order alone is what we have +to reason upon; and to reason without data is nothing but delusion. A +theory, therefore, which is limited to the actual constitution of this +earth, cannot be allowed to proceed one step beyond the present order of +things. + +But, having surveyed the order of this living world, and having +investigated the progress of this active scene of life, death and +circulation, we find ample data on which to found a train of the most +conclusive reasoning with regard to a general design. It is thus that +there is to be perceived another system of active things for the +contemplation of our mind;--things which, though not immediately within +our view, are not the less certain in being out of our sight; and things +which must necessarily be comprehended in the theory of the earth, if we +are to give stability to it as a world sustaining plants and animals. +This is a mineral system, by which the decayed constitution of an earth, +or fruitful surface of habitable land, may be continually renewed in +proportion as it is wasted in the operations of this world. + +It is in this mineral system that I have occasion to compare the +explanations, which I give of certain natural appearances, with the +theories or explanations which have been given by others, and which are +generally received as the proper theory of those mineral operations. I +am, therefore, to examine those different opinions, respecting the +means employed by nature for producing particular appearances in the +construction of our land, appearances which must be explained in some +consistent mineral theory. + +These appearances may all be comprehended under two heads, which are now +to be mentioned, in order to see the importance of their explanation, or +purpose which such an explanation is to serve in a theory of the earth. +The first kind of these appearances is that of known bodies which we +find composing part of the masses of our land, bodies whose natural +history we know, as having existed in another state previous to the +composition of this earth where they now are found; these are the +relicts or parts of animal and vegetable bodies, and various stony +substances broken and worn by attrition, all which had belonged to a +former earth. By means of these known objects, we are to learn a great +deal of the natural history of this earth; and, it is in tracing that +history, from where we first perceive it, to the present state of +things, that forms the subject of a geological and mineralogical theory +of this earth. But, we are more especially enabled to trace those +operations of the earth, by means of the second kind of appearances, +which are now to be mentioned. + +These again are the evident changes which those known bodies have +undergone, and which have been induced upon such collected masses of +which those bodies constitute a part. These changes are of three sorts; +_first_, the solid state, and various degrees of it, in which we now +find those masses which had been originally formed by the collection of +loose and incoherent materials; _secondly_, the subsequent changes which +have evidently happened to those consolidated masses which have been +broken and displaced, and which have had other mineral substances +introduced into those broken and disordered parts; and, _lastly_, that +great change of situation which has happened to this compound mass +formed originally at the bottom of the sea, a mass which, after being +consolidated in the mineral region, is now situated in the atmosphere +above the surface of the sea. + +In this manner we are led to the system of the world, or theory of the +earth in general; for, that great change of situation, which our land +has undergone, cannot be considered as the work of accident, or any +other than an essential part in the system of this world. It is +therefore a proper view of the necessary connection and mutual +dependence of all those different systems of changing things that forms +the theory of this earth as a world, or as that active part of nature +which the philosophy of this earth has to explore. The animal system is +the first or last of these; next comes the vegetable system, on which +the life of animals depends; then comes the system of this earth, +composed of atmosphere, sea, and land, and comprehending the various +chemical, mechanical, and meteorologically operations which take place +upon that surface where vegetation must proceed; and, lastly, we have +the mineral system to contemplate, a system in which the wasting surface +of the earth is employed in laying the foundation of future land within +the sea, and a system in which the mineral operations are employed in +concocting that future land. + +Now, such must surely be the theory of this earth, if the land is +continually wasting in the operations of this world; for, to acknowledge +the perfection of those systems of plants and animals perpetuating their +species, and to suppose the system of this earth on which they must +depend, to be imperfect, and in time to perish, would be to reason +inconsistently or absurdly. This is the view of nature that I would wish +philosophers to take; but, there are certain prejudices of education or +prepossession of opinion among them to be overcome, before they can be +brought to see those fundamental propositions,--the wasting of the land, +and the necessity of its renovation by the co-operation of the mineral +system. Let us then consider how men of science, in examining the +mineral state of things, and reasoning from those appearances by which +we are to learn the physiology of this earth, have misled themselves +with regard to physical causes, and formed certain mineralogical and +geological theories, by which their judgment is so perverted, in +examining nature, as to exclude them from the proper means of correcting +their first erroneous notions, or render them blind to the clearest +evidence of any other theory that is proposed. + +When men of science reason upon subjects where the ideas are distinct +and definite, with terms appropriated to the ideas, they come to +conclusions in which there is no difference of opinion. It is otherwise +in physical subjects, where things are to be assimilated, in being +properly compared; there, things are not always compared in similar and +equal circumstances or conditions; and there, philosophers often draw +conclusions beyond the analogy of the things compared, and thus judge +without data. When, for example, they would form the physical induction, +with regard to the effect of fire or water upon certain substances in +the mineral regions, from the analogy of such events as may be observed +upon the surface of the earth, they are apt to judge of things acting +under different circumstances or conditions, consequently not producing +similar effects; in which case, they are judging without reason, that +is, instead of inductive reasoning from actual data or physical truth, +they are forming data to themselves purely by supposition, consequently, +so far as these, imagined data may be wrong, the physical conclusion, of +these philosophers may be erroneous. + +It is thus that philosophers have judged, with regard to the effects of +fire and water upon mineral substances below the bottom of the sea, +from what their chemistry had taught them to believe concerning bodies +exposed to those agents in the atmosphere or on the surface of the +earth. If in those two cases the circumstances were the same, or +similar, consequently the conditions of the action not changed, then, +the inductive reasoning, which they employ in that comparison, would be +just; but, so far as it is evidently otherwise, to have employed that +inductive conclusion for the explanation of mineral appearances, without +having reason to believe that those changed circumstances of the case +should not make any difference in the action or effect, is plainly to +have transgressed the rules of scientific reasoning; consequently, +instead of being a proper physical conclusion, it is only that imperfect +reasoning of the vulgar which, by comparing things not properly analysed +or distinguished, is so subject to be erroneous. This vague reasoning, +therefore, cannot be admitted as a part of any geological or mineral +theory. Now I here maintain, that philosophers have judged in no other +manner than by this false analogy, when they conclude that water is the +agent by which mineral concretions have been formed. But it will be +proper to state more particularly the case of that misunderstanding +among mineral philosophers. + +In forming a geological theory, the general construction of this earth, +and the materials of which it is composed, are such visible objects, and +so evident to those who will take the pains to examine nature, that +here is a subject in which there cannot be any doubt or difference of +opinion. Neither can there be any dispute concerning the place and +situation of mass when it was first formed or composed; for, this is +clearly proved, from every concomitant circumstance, to have been at the +bottom of the sea. The only question in this case, that can be made, is, +How that mass comes now to be a solid body, and above the surface of the +sea in which it had been formed? + +With regard to the last, the opinions of philosophers have been so +dissonant, so vague, and so unreasonable, as to draw to no conclusion. +Some suppose the land to be discovered by the gradual retreat of the +ocean, without proposing to explain to us from whence had come the known +materials of a former earth, which compose the highest summits of the +mountains in the highest continents of the earth. Others suppose the +whole of a former earth to have subsided below the bottom even of the +present sea, and together with it all the water of the former sea, from +above the summits of the present mountains, which had then been at the +bottom of the former sea. The placing of the bottom of the sea, or any +part of it, in the atmosphere so as to be dry land, is no doubt a great +operation to be performed, and a difficult task to be explained; but +this is only an argument the more for philosophers to agree in adopting +the most reasonable means. + +But though philosophers differ so widely in that point, this is not the +case with regard to the concretion of mineral bodies; here mineralists +seem to be almost all of one mind, at the same time without any reason, +at least, without any other reason than that false analogy which they +have inconsiderately formed from the operations of the surface of this +earth. This great misunderstanding of mineralists has such an extensive +and baneful effect in the judging of geological theories, that it +will be proper here to explain how that has happened, and to shew the +necessity of correcting that erroneous principle before any just opinion +can be formed upon the subject. + +Fire and water are two great agents in the system of this earth; it is +therefore most natural to look for the operation of those agents in the +changes which are made on bodies in the mineral regions; and as the +consolidated state of those bodies, which had been collected at the +bottom of the sea, may have been supposed to be induced either by +fusion, or by the concretion from a solution, we are to consider how far +natural appearance lead to the conclusion of the one or other of those +two different operations. Here, no doubt, we are to reason analogically +from the known power and effects of those great agents; but, we must +take care not to reason from a false analogy, by misunderstanding the +circumstances of the case, or not attending to the necessary conditions +in which those agents act.--We must not conclude that fire cannot burn +in the mineral regions because our fires require the ventilation of the +atmosphere; for, besides the actual exigence of mineral fire being a +notorious matter of fact, we know that much more powerful means _may_ +be employed by nature, for that mineral purpose of exciting heat, than +those which we practise.--We must not conclude that mineral marble is +formed in the same manner as we see a similar stony substance produced +upon the surface of the earth, unless we should have reason to suppose +the analogy to be complete. But, this is the very error into which +mineral philosophers have fallen; and this is the subject which I am now +to endeavour to illustrate. + +The manner in which those philosophers have deceived themselves when +reasoning upon the subject of mineral concretion, is this: They see, +that by means of water a stony substance is produced; and, this stony +body so much resembles mineral marble as to be hardly distinguishable in +certain cases. These mineral philosophers then, reasoning in the manner +of the vulgar, or without analysing the subject to its principle, +naturally attribute the formation of the mineral marble to a cause +of the same sort; and, the mineral marble being found so intimately +connected with all other mineral bodies, we must necessarily conclude, +in reasoning according to the soundest principles, that all those +different substances had been concreted in the same manner. Thus, having +once departed one step from the path of just investigation, our physical +science is necessarily bewildered in the labyrinth of error. Let us +then, in re-examining our data, point out where lies that first devious +step which had been impregnated with fixed air, or carbonic acid gas, +(as it is called), dissolves a certain portion of mild calcareous +earth or marble; consequently such acidulated water, that is, water +impregnated with this gas, will, by filtrating through calcareous +substances, become saturated with that solution of marble; and, this +solution is what is called a _petrifying water_. When this solution is +exposed to the action of the atmosphere, the acid gas, by means of which +the stony substance is dissolved, evaporates from the solution, in +having a stronger attraction for the atmospheric air; it is then that +the marble, or calcareous substance, concretes and crystallises, +separating from the water in a sparry state, and forming a very solid +stone by the successive accretion from the solution, as it comes to +be exposed to the influence of the atmosphere in flowing over the +accumulating body. Here is the source of their delusion; for, they do +not distinguish properly the case of this solution of a stony substance +concreting by means of the separation of its solvent, and the case of +such a solution being in a place where that necessary condition cannot +be supposed to exist; such as, e.g., the interstices among the particles +of sand, clay, etc. deposited at the bottom of the sea, and accumulated +in immense stratified masses. + +No example can better illustrate how pernicious it is to science to have +admitted a false principle, on which a chain of reasoning is to proceed +in forming a theory. Mineral philosophers have founded their theory upon +that deceitful analogy, which they had concluded between the stalactical +concretions of petrifying waters and the marble formed in the mineral +regions; thus, blinded by prejudice, they shut the door against the +clearest evidence; and it is most difficult to make them see the error +of their principle. But this is not to be wondered at, when we consider +how few among philosophising men remount to the first principles of +their theory; and, unless they shall thus remount to that first step, +in which the concreting operation of a dissolved stony substance +is supposed to take place without the necessary conditions for the +petrifying operation, it is impossible to be convinced that their +theory, thus formed with regard to mineral concretion, is merely +supposition, and has no foundation in matter of fact from whence it +should proceed. + +But this is not all; for, even supposing their theory to be well founded +and just, it is plainly contradicted by natural appearances. According +to that theory of aqueous consolidation, all the stratified bodies, of +which this earth in general consists, should be found in the natural +order of their regular formation; but, instead of this, they are found +every where disturbed in that order more or less; in many places this +order and regularity is so disturbed as hardly to be acknowledged; in +most places we find those stratified bodies broken, dislocated, and +contorted, and this aqueous theory of mineralists has neither the means +for attaining that end, were it required in their theory, nor have they +any such purpose in their theory, were that end attainable by the means +which they employ. Thus blinded by the prejudice of a false analogy, +they do not even endeavour to gratify the human understanding (which +naturally goes in quest of wisdom and design) by forming a hypothetical +or specious theory of the mineral system; and they only amuse themselves +with the supposition of an unknown operation of water for the +explanation of their cabinet specimens, a supposition altogether +ineffectual for the purpose of forming a habitable earth, and a +supposition which is certainly contradicted by every natural appearance. + +Thus, in examining geological and mineralogical theories, I am laid +under the disagreeable necessity of pointing out the errors of physical +principles which are assumed, the prejudices of theoretical opinions +which have been received, and the misconceived notions which +philosophers entertain with regard to the system of nature, in which may +be perceived no ineffectual operation, nor any destructive intention, +but the wise and benevolent purpose of preserving the present order of +this world. But, though thus misled with regard to the cause of things, +naturalists are every where making interesting observations in the +mineral kingdom, I shall therefore avail myself of that instructive +information, for the confirmation of my theory. + +It may now be proper to consider what must be required, in order to have +a geological and mineral theory established upon scientific principles, +or on such grounds as must give conviction to those who will examine +the subject; for, unless we may clearly see that there are means for +attaining that desirable end, few philosophers will be persuaded to +pursue this branch of knowledge. + +A theory is nothing but the generalization of particular facts; and, in +a theory of the earth, those facts must be taken from the observations +of natural history. Nature is considered as absolutely true; no error or +contradiction can be found in nature. For, if such contradiction were +truly found, if the stone, for example, which fell to day were to rise +again to-morrow, there would be an end of natural philosophy, our +principles would fail, and we would no longer investigate the rules of +nature from our observations. + +Every natural appearance, therefore, which is explained, _i.e._ which is +made to come into the order of things that happen, must so far confirm +the theory to which it then belongs. But is it necessary, that every +particular appearance, among minerals, should be thus explained in +a general theory of the earth? And, is any appearance, which is not +explained by it, to be considered as sufficient to discredit or confute +a theory which corresponded with every other appearance? Here is a +question which it would require some accuracy to resolve. + +If we knew all the powers of nature, and all the different conditions in +which those powers may have their action varied, that is to say, if we +were acquainted with every physical cause, then every natural effect, or +all appearances upon the surface of this earth, might be explained in a +theory that were just. But, seeing that this is far from being the case, +and that there may be many causes of which we are as yet ignorant, as +well as certain conditions in which the known action of powers may be +varied, it must be evident, that a theory of the earth is not to be +confuted by this argument alone, That there are, among natural bodies, +certain appearances which are not explained by the theory. We must +admit, that, not having all the data which natural philosophy requires, +we cannot pretend to explain every thing which appears; and that our +theories, which necessarily are imperfect, are not to be considered as +erroneous when not explaining every thing which is in nature, but only +when they are found contrary to or inconsistent with the laws of nature, +which are known, and with which the case in question may be properly +compared. + +But we may have different theories to compare with nature; and, in that +case, the question is not, How far any of those theories should explain +all natural appearances? but, How far any one particular theory might +explain a phenomenon better than another? In this case of comparison, it +will be evident, that if one theory explains natural appearances, then +the opposite to that theory cannot be supposed to explain the same +appearances. If for example, granite, porphyry, or basaltes, should be +found naturally formed by fusion, the formation of those stones could +not be supposed in any case as formed by water, although it could not +be demonstrated that water is incapable of forming those mineral +productions. + +In like manner, if those three bodies were proved to have been actually +formed by water alone, then, in other cases where we should have no +proof, they could not be supposed as having been formed by fire or +fusion. It must be evident, that an equal degree of proof of those two +different propositions would leave our judgment in suspence, unless that +proof were perfect, in which case, we would have two different causes +producing similar effects. But, if we shall have a sufficient proof +upon the one side, and only a presumptive proof or probability upon the +other, we must reject that probability or presumption, when opposed by +a proof, although that proof were only an induction by reasoning from +similar effects as following similar causes. _A fortiori_, if there be +on one side a fair induction, without the least suspicion of error, +and on the other nothing but a mere presumption founded upon a distant +analogy, which could not even properly apply, then, the inductive proof +would be as satisfactory as if there had not been any supposition on the +opposite side. + +So far as a theory is formed in the generalization of natural +appearances, that theory must be just, although it may not be perfect, +as having comprehended every appearance; that is to say, a theory is +not perfect until it be founded upon every natural appearance; in which +case, those appearances will be explained by the theory. The theory of +gravitation, though no ways doubtful, was not so perfect before the +shape of this globe had been determined by actual measurement, and +before the direction of the plummet had been tried upon Shihallion, as +after those observations had been made. But a theory which should be +merely hypothetical, or founded upon a few appearances, can only be +received as a theory, after it has been found to correspond properly +with nature; it would then be held a proper explanation of those natural +appearances with which it corresponded; and, the more of those phenomena +that were thus explained by the theory, the more would that, which had +been first conjectural, be converted into a theory legitimately founded +upon natural appearances. + +Matter of fact is that upon which science proceeds, by generalization, +to form theory, for the purpose of philosophy, or the knowledge of all +natural causes; and it is by the companion of these matters of fact with +any theory, that such a theory will be tried. But, in judging of matter +of fact, let us be cautious of deceiving ourselves, by substituting +speculative reasoning in place of actual events. + +Nature, as the subject of our observation, consists of two sorts of +objects; for, things are either active, when we perceive change to take +place in consequence of such action, or they are quiescent, when we +perceive no change to take place. Now, it is evident, that in judging +of the active powers of nature from the quiescent objects of our +information, we are liable to error, in misinterpreting the objects +which we see; we thus form to ourselves false or erroneous opinion +concerning the general laws of action, and the powers of nature. In +comparing, therefore, generalised facts, or theory, with particular +observations, there is required the greatest care, neither, on the one +hand, to strain the appearances, so as to bring in to the theory a fact +belonging to another class of things; nor, on the other, to condemn a +proper theory, merely because that theory has not been extended to the +explanation of every natural appearance. + +But, besides the misinterpretation of matters of fact, we are also to +guard against the misrepresentation of natural appearances. Whether +warped by the prejudice of partial and erroneous theory, or deceived by +the inaccuracy of superficial observation, naturalists are apt to see +things in an improper light, and thus to reason from principles which +cannot be admitted, and, which often lead to false conclusions. A +naturalist, for example, comes to examine a cavity in the mines, he +there finds water dropping down all around him, and he sees the cavity +all hung with siliceous crystals; he then concludes, without hesitation, +that here is to be perceived cause and effect, or that he actually sees +the formation of those crystallizations from the operation of water. It +is thus that I have been told by men of great mineral knowledge, men who +must have had the best education upon that subject of mineralogy, and +who have the superintendance of great mineral concerns in Germany, that +they had actually seen nature at work in that operation of forming +rock-crystal;--they saw what I have now described; they could see no +more; but, they saw what had convinced them of that which, there is +every reason to believe, never happened. With regard to my theory, +I wish for the most rigorous examination; and do not ask for any +indulgence whatever, whether with regard to the principles on which the +theory is built, or for the application of the theory to the explanation +of natural appearances. But, let not geologists judge my theory by their +imperfect notions of nature, or by those narrow views which they take of +the present state of things;--let not mineralogists condemn my theory, +for no other reason but because it does not correspond with their false +principles, and those gratuitous suppositions by which they had been +pleased to explain to themselves every thing before. First let them look +into their own theory, and correct that erroneous principle, with regard +to the action of water, or the assumption of unknown causes, upon which +they have reasoned in forming their vague notions of the mineral region, +before they can be properly qualified to examine, impartially, a theory +which employs another principle. Every thing which has come under my +observation shall be, as far as I can, faithfully related; nor shall I +withhold those which neither the present theory, nor any other that I am +acquainted with, can, I think, explain. + +Appearances cannot well be described except in relation to some theory +or general arrangement of the subject; because the particular detail, +of every part in a complicated appearance, would be endless and +insignificant. When, however, any question in a theory depends upon the +nature of an appearance, we cannot be too particular in describing that +by which the question is to be decided. But though it be sometimes +proper to be minute in a particular, it is always, and above all things, +necessary to be distinct; and not to confound together things which are +of different natures. For, though it be by finding similarity, in things +which at first sight may seem different, that science is promoted and +philosophy attained, yet, we must have a distinct view of those things +which are to be assimilated; and surely the lowest state of knowledge +in any subject, is the not distinguishing things which, though not to +common observation different, are not truly the same. + +To confound, for example one stone with another, because they were both +hard, friable, and heavy, would be to describe, with the superficial +views of vulgar observation; whereas science specifies the weight and +hardness, and thus accurately distinguishes the stone. + +Before naturalists had learned to distinguish what they saw, and to +describe, in known terms, those natural appearances, a theorist must +have generalised only from his proper observation. This has been my +case. When I first conceived my theory, few naturalists could write +intelligibly upon the subject; but that is long ago, and things are much +altered since; now there are most enlightened men making observations, +and communicating natural knowledge. I have the satisfaction, almost +every day, to compare the theory, which I had formed from my proper +observations, with the actual state of things in almost every quarter of +the globe. + +Whether, therefore, we mean to try a theory by its application to +such phenomena as are well understood, or to learn something from the +application of particular phenomena to a well established theory, +we shall always find it interesting to have appearances described; +particularly such as may be referred to some general rule, as +circumscribing it to certain conditions, or as finding rule in rule, +that is to say, discovering those particular conditions in which the +general laws of action may be affected. + +Instead, for example, of the rule which we find in the application of +heat for the fusion and evaporation of mineral substances upon the +surface of this earth, we may find it necessary to consider the effect +which changed circumstances produce in the mineral regions, and occasion +a change of that rule of action which we have learned from experience, +when melting and evaporating those substances in the atmosphere or on +the surface of the earth. + +It is in this manner that a theory, which was formed by the +generalization of particular facts, comes to be a source of information, +by explaining to us certain appearances which otherwise we could not +understand. Thus, it was not the appearance of the tides that taught the +theory of gravitation; it was the theory of gravitation that made us +understand the appearance of the tides. In like manner, the law of +gravitation, which was demonstrated from the motion of the moon in her +orbit round this earth, when applied to the paths of comets, explained +that appearance. Our theory, of a central fire, has been formed upon +the consolidation of the strata of this earth; but this theory is to be +applied for the explanation of various different appearances. In this +manner, two different purposes will be served; the trying of the theory +by its application to phenomena; and the explanation of phenomena by the +principles laid open in the theory. + +I may repeat it; a theory of the earth must ultimately depend upon +matter of fact or particular observation; but those observations must be +distinct, and those distinguished things must be generalised. We have +just now given for an example, a distinction among stones, in knowing +them by their sensible qualities. But, besides distinguishing those +objects, we are also to inquire into the origin and cause of those +things which are distinguished. Here, again, we take into our aid the +chemical as well as the mechanical properties of these several things; +and hence learn to know on what their natural form and constitution may +depend. Having thus attained the natural philosophy of stones, we next +inquire into the place and application of those things in nature; and +in this manner we acquire some knowledge with regard to the natural +constitution of this earth. We find this earth composed of known things; +it is therefore the operations, required in these compositions, which +form the natural philosophy of this earth, considered as a body of solid +land. But, the solid land is only one part of the globe; therefore, +the philosophy of the globe proceeds still farther by knowing the +constitution of this planetary body, as consisting of different parts +united for a purpose, which is that of a world. + +The general theory of this earth as a world, will thus appear to be a +complex thing, which however founded upon simple principles, contains +many subjects of discussion, and requires attention to a variety of +particulars. For, not only the great features of this earth are to be +explained by the theory, but also the most minute appearance, such as +are to be found, even with microscopic observation, in every particular +part. + +Thus the nature, constitution, and cause of every particular appearance +in the construction of this earth, are to be investigated in a +geological theory, as well as that general constitution of the world in +which all the particular parts are to be employed for a purpose. + +If the subject here examined shall be found properly explained, there +will remain little doubt with regard to the justness of the theory, +which will then be applicable to other appearances that may occur; +although every appearance is not to be explained, in a manner equally +satisfactory, by any theory which is not perfect. + +The first subject to be examined is the modern theory of primitive +mountains. I have written several chapters upon that subject, having +successively acquired more light in this interesting part of the theory, +by observations of my own in several places of this country, as well as +from the natural history of other countries. I shall give these nearly +in the order in which they occurred, or had been written. + + + +CHAP. IV. + +The Supposition of Primitive Mountains refuted. + +In the theory now given, the earth has been represented as a composition +of different materials, which had existed in another form, and as the +effect of natural operations; therefore, however various may be found +the structure of our earth, and however dissimilar some parts of +its composition may be in comparison with others, no part should be +considered as original, in relation to the globe, or as primitive, in +relation to second causes, _i.e._ physical operations by which those +parts should have been formed. But it is pretended by naturalists, that +there are certain primitive mountains in the earth, bodies which have +had another origin than that of the general strata of the globe and +subsequent masses; an origin, therefore, which cannot be considered as +having been produced from natural operations, or as effected in the +course of known causes. Now, if it can be made to appear, that there is +no solid ground for this distinction; and if it can be shown, that there +is truly no mineral body in this earth which may not have been produced +by operations natural to the globe, we should thus procure a certain +confirmation of the doctrine. This also will be the more interesting, +in being deduced from a part of natural appearances, which seemed to be +inconsistent with the theory. + +Certain masses or mountains of granite, are the only bodies of this +earth which have apparently a certain pretension to this species +of originality. These, therefore, must be now the subject of our +examination. + +Granite, considered by itself, does not appear to have any claim to +originality in its nature. It is composed of bodies which are capable of +being analyzed; and these are then found to be compositions of different +substances, which are also sometimes variously proportioned. The +feldspar and the mica, for example, as well as the schorl, are found +variously coloured in different granites, and coloured in various +proportions. Besides the variety in the composition, or chemical mixture +of the different bodies which compose granite, this rock admits of a +great diversity, from the variety of its mechanical mixture, or from +the different species of bodies which are its constituent parts. M. de +Saussure, who has examined this subject perhaps more than any other +person, and who has had the very best opportunities for this purpose, +says, that this composition may be found in all the different +combinations which may be produced by every possible composition of 7 +or 8 different kinds of stone, (page 108, Voyage dans les Alpes, etc.). +Neither does this fill up the measure of its variety; for, another +source of change is found in the grain of this rock stone; I have a +specimen of this variety from the size almost of sand to that of some +inches. + +Were granite, therefore, to be supposed as in the original state of its +creation, nature would be considered as having operated in an indefinite +diversity of ways, without that order and wisdom which we find in all +her works; for here would be change without a principle, and variety +without a purpose. There is no reason, however, to suppose granite +original, more than any other composite rock, although we may be +ignorant of the particular process in which it is formed, and although, +comparatively in relation to certain other rocks, granite, or certain +masses of this composition, may be found of a more ancient date. + +If granite be truly stratified, and those strata connected with the +other strata of the earth, it can have no claim to originality; and +the idea of primitive mountains, of late so much employed by natural +philosophers, must vanish, in a more extensive view of the operations of +the globe; but it is certain that granite, or a species of the same kind +of stone, is thus found stratified. It is the _granit feuilletee_ of +M. de Saussure, and, if I mistake not, what is called _gneis_ by the +Germans. We have it also in our north alpine country of Scotland; of +this I have specimens, but have not seen it in its place. + +Granite being thus found stratified, the masses of this stone cannot be +allowed to have any right of priority over the schistus, its companion +in the alpine countries, although M. de Saussure, whose authority I +would revere, has given it for the following reason; that it is found +the most centrical in the chains of high mountains, or in alpine +countries. Now, supposing this fact to be general, as he has found it in +the Alps, no argument for the priority of those masses can be founded +either upon the height or the situation of those granite mountains; for +the height of the mountain depends upon the solidity and strength of the +stone. Now though it is not to be here maintained that granite is the +most durable of those alpine rocks, yet as a mountain, either granite in +general, or in particular, certain species of it, may be esteemed such, +consequently, this massy stone, remaining highest in the mountainous +region, will naturally be considered as the centre, and according to +this rule, as having the pre-eminence in point of seniority. + +The rock which stands in competition with granite for the title of +primitive in the order of mountains, is that micaceous stratified stone +which is formed chiefly of quartz, but which admits of great variety +like the granite. The difference between those two bodies does not +consist in the materials of which they are composed, for, in their +varieties, they may be in this respect the same, but in a certain +regularity of composition, in this alpine stone, which evidently arises +from stratification or subsidence in water. + +If we shall thus consider all the varieties of this alpine stone as +being of one kind, and call it granite, then we shall distinguish in +this body two different species, from whence perhaps some interesting +conclusion may be formed with regard to the operations of the globe. +These two species are, _first_, granite regular in its composition, or +stratified in its construction; and, _secondly_, granite in mass, or +irregular in its construction. Let us now endeavour to make use of these +generalizations and distinctions. + +In examining the great diversity of our whinstone, trap, or basaltes, it +is found at last to granulate into granite; at the same time those two +different species of rock-stone may be distinguished. A perfect granite +has not in its composition necessarily any argillaceous earth, farther +than may be in the natural constitution of its distinct parts; whereas, +a perfect basalt may have abundance of this substance, without any +quartz or any siliceous body. A perfect granite, is, therefore, an +extremely hard stone, having quartz and feldspar for its basis; but a +perfect whin or basaltes may be extremely soft, so as to cut easily with +a knife. In like manner granite is a composition which graduates into +porphyry; but porphyry is only whinstone of a harder species. Therefore, +though perfectly distinct, those three things graduate into each other, +and may be considered as the same. + +Granite and whinstone, or basaltes, though distinct compositions, thus +graduating into each other; and whinstone, as well as porphyry, being +without doubt a species of lava, we may consider the granite which is +found in mass without stratification, in like manner as we do the masses +of whinstone, basaltes, or Swedish trap, as having flowed in the bowels +of the earth, and thus been produced by the chance of place, without any +proper form of its own, or in an irregular shape and construction. In +this manner would be explained the irregular shape or structure of those +granite masses; and thus great light would be thrown upon the waved +structure of the stratified alpine stone, which, though it has not been +made to flow, has been brought to a great degree of softness, so as to +have the original straight lines of its stratification changed to +those undulated or waving lines which are in some cases extremely much +incurvated. + +It remains only to confirm this reasoning, upon our principles, by +bringing actual observation to its support; and this we shall do from +two of the best authorities. The Chevalier de Dolomieu, in describing +the volcanic productions of Etna, mentions a lava which had flowed from +that mountain, and which may be considered as a granite. But M. de +Saussure has put this matter out of doubt by describing most accurately +what he had seen both in the Alps and at the city of Lyons. These are +veins of granite which have flowed from the contiguous mass into the +stratified stone, and leave no doubt with regard to this proposition, +that the granite had flowed in form of subterranean lava, although M. de +Saussure has drawn a very different conclusion from this appearance. I +have also a specimen from this country of a vein of granite in a granite +stone, the vein being of a smaller grain than that of the rock which it +traverses.[20] + +[Note 20: This is what I had wrote upon, the subject of granite, before +I had acquired such ample testimony from my own observations upon +that species of rock. I have given some notice, in the 3d vol. of the +Transactions of the Edinburgh R.S. concerning the general result of +those observations, which will be given particularly in the course of +this work.] + +It will thus appear, that the doctrine which of late has prevailed, of +primitive mountains, or something which should be considered as original +in the construction of this earth, must be given up as a false view of +nature, which has formed the granite upon the same principle with that +of any other consolidated stratum; so far as the collection of different +materials, and the subsequent fusion of the compound mass, are necessary +operations in the preparation of all the solid masses of the earth. +Whatever operations of the globe, therefore, may be concluded from the +composition of granite masses, as well as of the alpine strata, these +must be considered as giving us information with regard to the natural +history of this earth; and they will be considered as important, in +proportion as they disclose to us truths, which from other strata might +not be so evident, or at all made known. + +Let us now examine the arguments, which, may be employed in favour of +that supposition of primitive mountains. + +The observations, on which naturalists have founded that opinion of +originality in some of the component parts of our earth, are these; +_first_, They observe certain great masses of granite in which +stratification is not to be perceived; this then they say is an original +mass, and it is not to be derived from any natural operation of the +globe; _secondly_, They observe considerable tracts of the earth +composed of matter in the order of stratification as to its general +composition, but not as to its particular position, the vertical +position here prevailing, instead of the horizontal which is proper to +strata formed in water; this, therefore, they also term primitive, and +suppose it to be from another origin than that of the subsidence of +materials moved in the waters of the globe; _lastly_, They observe both +strata and masses of calcareous matter in which they cannot distinguish +any marine body as is usual in other strata of the same substance; and +these calcareous masses being generally connected with their primitive +mountains, they have also included these collections of calcareous +matter, in which marine bodies are not observed, among the primitive +parts which they suppose to be the original construction of this globe. + +It may be proper to see the description of a calcareous alpine mountain. +M. de Saussure gives us the following observations concerning a mountain +of this kind in the middle of the Alps, where the water divides in +running different ways towards the sea. It is in describing the passage +of the Bon-Homme, (Tom. 2. V. dans les Alpes). + +"Sec. 759. Sur la droite ou au couchant de ces rochers, on voit une +montagne calcaire etonnante dans ce genre par la hardiesse avec laquelle +elle eleve contre le ciel ses cimes aigues et tranchantes, taillees +a angles vifs dans le costume des hautes cimes de granit. Elle est +pourtant bien surement calcaire, je l'ai observee de pres, et on +rencontre sur cette route les blocs qui s'en detachent. + +"Cette pierre porte les caracteres des calcaires les plus anciennes; sa +couleur est grise, son grain assez fin, on n'y appercoit aucun vestige +de corps organises; ses couches sont peu epaisses, ondees et coupees +frequemment par des fentes paralleles entr'elles et perpendiculaires a +leurs plans. On trouve aussi parmi ces fragmens des breches calcaires +grises." + +Here is a mountain which will rank with the most primitive of the earth; +But why? only because it is extremely consolidated without any mark of +organised body. Had there been in this mountain but one single shell, we +should not then have scrupled to conclude that the origin of this lofty +mountain had been the same with every marble or limestone in the earth. +But though, from the structure of this stone, there is no mark of its +having been formed immediately of the calcareous parts of animals, there +is every mark of those calcareous strata having been formed like other +marbles by deposit in the waters of the globe. + +These two things are also homologated by the equal or perfect +consolidation of their substance; for, as it is to be proved that +all stratified marbles have been consolidated by the fusion of their +substance, we must attribute the same consolidating cause to those +alpine masses; the frequent veins that divide those calcareous strata +which M. de Saussure has here described, also prove the nature of the +consolidating cause, (see Chap. 1. page 111.). + +This mountain, considered by itself, may perhaps afford no data by which +a naturalist might read the circumstances of its origin. But, Is a +theory of the earth to be formed upon such a negative observation? and, +Is there any particular in this mountain, that may not be shown in +others of which the origin is not in any degree doubtful? + +It is not to be disputed, that there are parts of the solid body of our +earth which may be considered as primary or prior, compared with others +that are posterior, in relation to the time of their formation, and much +less changed with regard to the state in which they had been originally +formed:--But it is here denied, that there are any parts of the earth +which do not appear to have had the same origin with all the rest, so +far as this consists in the collection of materials deposited at the +bottom of the waters[21]; for there is no solid mass of land that may +not be traced to this origin, either from its composition, or from its +local connection with other masses, the nature of which in this respect +are known. We have already given examples of this from sufficient +authority. The evidence, therefore, of those primary masses being +original in relation to the natural operations of the globe, is reduced +to this assertion, that there are no vestiges of organised bodies to be +found in those primary masses. Let us now examine how far this testimony +for the originality of those masses is to be admitted in fact and sound +reasoning. + +[Note 21: There are no collection of those alpine masses in which may +not be found in some of them sand, mica, and gravel; but these materials +prove the existence of an earth, on which those fragments of greater +masses had been formed, and more or less worn by attrition.] + +The matter in question at present is this, that there are certain tracts +of countries in which no vestige of organised bodies are found; now, let +us suppose the fact to be true or well grounded, Can we conclude +from this that there had been originally no organised bodies in the +composition of those masses?--Such a conclusion could only be formed in +making a supposition, that every organised body deposited in a mass +of matter, whether homogeneous or heterogeneous, should be preserved +without change, while the collected mass, in which it had been +deposited, changes as much as possible by the operation both of fire and +water. But this supposition is erroneous, and cannot be admitted; and +the study of marbles will demonstrate this truth, that the calcareous +relics of organised bodies are changed, in the consolidating operations +of the globe, in every degree, from the smallest alteration to the +greatest, when they become indistinguishable any farther to our sight. + +Therefore, from the supposition of no appearance of marine bodies in the +pretended primitive masses, there is no sufficient evidence or reason to +conclude, that those masses have not had a marine origin; because, the +traces of organised bodies may be obliterated by the many subsequent +operations of the mineral region; and which operations, the present +state of those masses certify beyond dispute. + +We are now to examine the fact, how far the ground on which that false +reasoning had been founded is strictly true. + +In the first place, then, it must be considered, that the alledged fact +is nothing but a negative assertion, importing that no mark of organised +bodies had been observed, in certain stones and strata which some +naturalists have examined with that view. But, though many naturalists +have looked for them without success, it does not follow that such marks +may not be found; it indeed proves that such a task is difficult, and +the success of it, to a particular, most precarious; accident, however, +may bring about what the greatest industry has not been able to attain. +Secondly, there is good reason to believe that this asserted negation +is not absolutely true; for I have in my possession what I consider as +proof of the contrary; I found it in Wales, and I think it is in what +may be considered as primitive mountains;--it is the mark of shells in a +stone of that kind. + +Thus, I had formed my opinion with regard to this alleged fact, long +before I had seen any description either of the Alps or Pyrennean +mountains; and now I have no reason to change that opinion. It may +indeed be alleged, that the strata of marble or limestone, containing +marine bodies found in those mountains, are secondary strata, and not +the primitive. To this I can give no reply, as the descriptions given of +those strata do not enable me to decide this point. + +At the village of Mat, under the Mont Blatten for example, there is a +quarry of schistus or black slate, in which are often found the print +and the bones of fishes. (Discours sur l'Histoire Naturelle de la +Suisse, page 225.). If this may be considered as an alpine or primitive +schistus, it would be decisive of the question: But it would require to +have it well ascertained that this schistus is truly one of those which +are esteemed primitive, or that it is properly connected with them. + +But though I cannot find in those interesting descriptions which we now +have got, any one which is demonstrative of this truth, that calcareous +marine objects are found in the primitive strata, this is not the +case with regard to another object equally important in deciding this +question, Whether the primitive strata are found containing the marks of +organised bodies? + +M. de Dellancourt, in his _Observations Mineralogiques_, Journal de +Physique Juillet 1786, in describing the mountains of Dauphine, gives us +the following fact with regard to those alpine vertical strata. + +"La pierre constituante de la montagne d'Oris est en general le _Kneifs_ +ou la roche feuilletee mica et quartz a couches plus ou moins ferrees +quelquefois le schorl en roche penetre de steatite. Les couches varient +infiniment quant a leur direction et a leur inclinaisons. Cette montagne +est cultivee et riche dans certain cantons, surtout autour du village +d'Oris, mais elle est tres-escarpee dans beaucoup d'autres. Entre le +village d'Oris et celui du Tresnay est une espece de combe assez creuse +formee par la chute des eaux des cimes superieures des rochers. Cette +combe offre beaucoup de schiste dont les couches font ou tres-inclinees +ou perpendiculaires. Entre ces couches il s'en est trouve de plus noires +que les autres et capable de bruler, mais difficilement. Les habitans +ont extrait beaucoup de cette matiere terreuse, et lui ont donne le nom +de charbon de terre. Ils viennent meme a bout de la faire bruler, et +de s'en servir l'hiver en la melant avec du bois. Ce schiste noir +particulier m'a paru exister principalement dans les endroits ou les +eaux se sont infiltrees entre les couches perpendiculaires, et y ont +entraine diverse matieres, et sur-tout des debris de vegetaux que +j'ai encore retrouves a demi-noirs, pulverulens et comme dans un etat +charbonneux." + +This formation of coal, by the infiltration of water and carrying in of +vegetable bodies, certainly cannot be admitted of; consequently, from +this description, there would seem to be strata of coal alternated with +the alpine schisti. But the formation of mineral coal requires vegetable +matter to have been deposited along with those earthy substances, at the +bottom of the sea. The production of vegetable bodies, again, requires +the constitution of sea and land, and the system of a living world, +sustaining plants at least, if not animals. + +In this natural history of the alpine schisti, therefore, we have a +most interesting fact, an example which is extremely rare. Seldom are +calcareous organised bodies found among those alpine strata, but still +more rarely, I believe, are the marks of vegetable bodies having +contributed in the formation of those masses. But however rare this +example, it is equally decisive of the question, Whether the alpine +schisti have had a similar origin as the other strata of the globe, +in which are found abundance of animal and vegetable bodies, or their +relics? and we are authorised to say, that since those perfect alpine +strata of Dauphine have had that origin, all the alpine schisti of the +globe have been originally formed in a similar manner. But to put this +matter out of doubt: + +In this summer 1788, coming from the Isle of Man, Mr Clerk and I +traveled through the alpine schistus country of Cumberland and +Westmoreland. We found a limestone quarry upon the banks of Windermere, +near the Low-wood Inn. I examined this limestone closely, but despaired +of finding any vestige of organised body. The strata of limestone +seem to graduate into the slate or schistus strata, between which the +calcareous are placed. Fortunately, however, I at last found a fragment +in which I thought to perceive the works of organised bodies in a +sparry state; I told Mr Clerk so, and our landlord Mr Wright, who had +accompanied us. I have brought home this specimen, which I have now +ground and polished; and now it is most evidently full of fragments of +entrochi. Mr Wright then told me he had seen evident impressions of +marine objects, as I understood from the description, in the slate of +those mountains; and he was to send me specimens so soon as he could +procure them. + +Here is one specimen which at once overturns all the speculations formed +upon that negative proposition. The schistus mountains of Cumberland +were, in this respect, as perfect primitive mountains as any upon the +earth, before this observation; now they have no claim upon that score, +no more than any limestone formed of shells. + +When I first announced my belief that such objects in natural history +might be found, I little thought to have seen it realised, to such a +degree as has now happened in the little circle of my knowledge. In the +summer 1791, + +Professor Playfair was to pass through Cumberland. I begged that he +would inquire of Mr Wright, at the Low-wood Inn, for those objects which +he was to endeavour to procure for me, and to examine the limestone +quarry in which I had found the specimen with entrochi. He went through +another part of those primary mountains, and has found examples of this +kind in the schisti; concerning which he has written me the following +account. + +"In a visit which I made to the Lakes of Cumberland in September 1791, +in company with the Hon. Francis Charteris, I met with a limestone +full of marine objects, though from its position it is certainly to be +reckoned among the primary strata. The place where we found this stone +was in the district of Lancashire, that is west of Windermere Lake, on +the road from Ambleside to the north end of Coniston Lake, and not far +from the point when you come in sight of the latter. Just about this +spot we happened to meet with one of those people who serve as guides +to travelers in those parts, and who told us, among other things, that +stones with shells in them were often found not far from where we were +then walking. We immediately began to look about for specimens of that +kind, and soon met with several; the most remarkable of which was in a +rock that rose a little above the surface, about 300 or 400 yards to +the right of the road. It was a part of a limestone stratum, nearly +vertical, and was full of bivalves with the impressions as strong as +in a common secondary limestone. The strata on both sides had the same +inclination, and were decidedly primary, consisting of the ordinary +micaceous schistus. This however I need not remark to you, who know so +well from your own observations that the whole of the country I am now +speaking of has every character of a primary one. I, only mention it, +that it may not be supposed that the rock in question was some fragment +of a secondary stratum that remained, after the rest was washed away, +superincumbent on the primary. + +"After I had seen this rock, I recollected that you had told me of +something of the same kind that you saw in a quarry at Low-wood Inn; and +it may be that both belonged to the same stratum or body of strata; for +the direction of the strata, as nearly as I could observe, was from S.W. +to N.E.; and this also is nearly the bearing of Low-wood from the place +where we now were. I send you a specimen, which you can compare with +those you brought from the lime quarry at Low-wood." + +I have examined this specimen, and find it to be the common schistus +of that country, only containing many bivalve shells and fragments of +entrochi and madrapore bodies, and mixed with pyrites. + +I have already observed that one single example of a shell, or of its +print, in a schistus, or in a stone stratified among those vertical or +erected masses, suffices to prove the origin of those bodies to have +been, what I had maintained them to be, water formed strata erected from +the bottom of the sea, like every other consolidated stratum of the +earth. But now, I think, I may affirm, that there is not, or rarely, any +considerable extent of country of that primary kind, in which some mark +of this origin will not be found, upon careful examination; and now I +will give my reason for this assertion. I have been examining the south +alpine country of Scotland, occasionally, for more than forty years +back, and I never could find any mark of an organised body in the +schistus of those mountains. It is true that I know of only one place +where limestone is found among the strata; this is upon Tweed-side near +the Crook. This quarry I had carefully examined long ago, but could find +no mark of any organised body in it. I suppose they now are working some +other of the vertical strata near those which I had examined; for, in +the summer 1792, I received a letter from Sir James Hall, which I shall +now transcribe. It is dated at Moffat, June 2. 1792. + +"As I was riding yesterday between Noble-house and Crook, on the road to +this place, I fell in with a quarry of alpine limestone; it consists of +four or five strata, about three feet thick, one of them single, and the +rest contiguous; they all stand between the strata of slate and schist +that are at the place nearly vertical. In the neighbourhood, a slate +quarry is worked of a pure blue slate; several of the strata of slate +near the limestone are filled with fragments of limestone scattered +about like the fragments of schist in the sandstone in the neighbourhood +of the junction on our coast.[22] + +[Note 22: This has a reference to very curious observations which we +made upon the east coast where these mountains terminate, and which I am +to describe in the course of this work.] + +"Among the masses of limestone lately broken off for use, and having the +fractures fresh, I found the forms of cockles quite distinct; and in +great abundance.--I send you three pieces of this kind," etc. + +It may perhaps be alleged that those mountains of Cumberland and +Tweedale are not the primary mountains, but composed of the secondary +schistus, which is every where known to contain those objects belonging +to a former earth. Naturalists who have not the opportunity of +convincing themselves by their proper examination, must judge with +regard to that geological fact by the description of others. Now it is +most fortunate for natural history, that it has been in this range of +mountains that we have discovered those marks of a marine origin; for, +I shall afterwards have occasion to give the clearest light into this +subject, from observations made in other parts of those same mountains +of schist, by which it will be proved that they are the primary +strata; and thus no manner of doubt will then remain in the minds +of naturalists, who might otherwise suspect that we were deceiving +ourselves, by mistaking the secondary for the primitive schistus. + +I have only farther to observe, that those schisti mountains of Wales, +of Cumberland, and of the south alpine part of Scotland, where these +marine objects have been found, consist, of that species of stone which +in some places makes the most admirable slate for covering houses; and, +in other parts, it breaks into blocks that so much resemble wood in +appearance, that, without narrow inspection, it might pass for petrified +wood. + +We are therefore to conclude that the marks of organised bodies in those +primary mountains are certainly found; at the same time the general +observation of naturalists has some foundation, so far as the marks of +organised bodies are both rarely to be met with in those masses, and not +easily distinguished as such when they are found. + +But this scarcity of marine objects is not confined to those primary +mountains, as they are called; for among the most horizontal strata, or +those of the latest production, there are many in which, it is commonly +thought, no marine calcareous objects are to be found; and this is a +subject that deserves to be more particularly considered, as the theory +may thus receive some illustration. + +Sandstone, coal, and their accompanying strata, are thought to be +destitute of calcareous marine productions, although many vestiges of +plants or vegetable productions are there perceived. But this general +opinion is neither accurate nor true; for though it be true that in the +coal and sandstone strata it is most common to find marks of vegetable +production, and rarely those calcareous bodies which are so frequent in +the limestone, yet it is not unusual for coal to be accompanied +with limestone formed of shells and corals, and also with ironstone +containing many of those marine objects as well as wood. Besides, +sandstone frequently contains objects which have been organised bodies, +but which do not belong to the vegetable kingdom, at least to no plant +which grows upon the land, but would seem to have been some species of +zoophite perhaps unknown. + +I have also frequently seen the vestige of shells in sandstone, although +in these strata the calcareous bodies are in general not perceived. +The reason of this is evident. When there is a small proportion of the +calcareous matter in the mass of sand which is pervious to steam and to +the percolation of water, the calcareous bodies may be easily dissolved, +and either carried away or dispersed in the mass; or even without being +thus dispersed by means of solution, the calcareous matter may be +absorbed by the siliceous substance of the stratum by means of fusion, +or by heat and cementation. The fact is, that I have seen in sandstone +the empty mould of marine shells with some siliceous crystallization, +so far as I remember, which corresponded perfectly with that idea. The +place I saw this was in a fine white sandstone accompanying the coal, +upon the sea side at Brora in Sutherland. + +Mineralogy is much indebted to Mr Pallas for the valuable observations +which he has given of countries so distant from the habitations of +learned men. The physiology of the globe has also been enriched with +some interesting observations from the labours of this learned traveller. +But besides giving us facts, Mr Pallas has also reasoned upon the +subject, and thus entered deep into the science of Cosmogeny; here it +is that I am afraid he has introduced some confusion into the natural +history of the earth, in not properly distinguishing the mineral +operations of the globe, and those again which belong entirely to the +surface of the earth; perhaps also in confounding the natural effects of +water upon the surface of the earth, with those convulsions of the sea +which may be properly considered as the accidental operations of the +globe. This subject being strictly connected with the opinions of that +philosopher with regard to primitive mountains, I am obliged to examine +in this place matters which otherwise might have come more properly to +be considered in another. + +M. Pallas in his _Observations sur la formation des montagnes_, (page +48) makes the following observations. + +"J'ai deja dit que _la bande de montagnes primitives schisteuses_ +heterogenes, qui, par toute la terre, accompagne les chaines +granitiques, et comprend les roches quartzeuses et talceuses mixtes, +trapezoides, serpentines, le schiste corne, les roches spathiques et +cornees, les grais purs, le porphyre et le jaspre, tous rocs feles +en couches, ou presque perpendiculaires, ou du moins tres-rapidement +inclinees, (les plus favorables a la filtration des eaux), semble +aussi-bien que le granit, anterieure a la creation organisee. Une raison +tres-forte pour appuyer cette supposition, c'est que la plupart de ces +roches, quoique lamelleuse en facon d'ardoise, n'a jamais produit +aux curieux la moindre trace de petrifactions ou empreintes de corps +organises. S'il s'en est trouve, c'est apparemment dans des fentes de +ces roches ou ces corps ont ete apportes par un deluge, et encastrees +apres dans une matiere infiltree, de meme qu'on a trouve des restes +d'Elephans dans le filon de la mine d'argent du Schlangenberg.[23] Les +caracteres par lesquels plusieurs de ces roches semblent avoir souffert +des effets d'un feu-tres-violent, les puissantes veines et amas des +mineraux les plus riches qui se trouvent principalement dans la bande +qui en est composee, leur position immediate sur le granit, et meme le +passage, par lequel on voit souvent en grand, changer le granit en une +des autres especes; tout cela indique une origine bien plus ancienne, +et des causes bien differentes de celles qui ont produit les montagnes +secondaires." + +[Note 23: This is a very natural way of reasoning when a philosopher +finds a fact, related by some naturalists, that does not correspond with +his theory or systematic view of things. Here our author follows the +general opinion in concluding that no organised body should be found in +their primitive strata; when, therefore, such an object is said to have +been observed, it is supposed that there may have been some mistake with +regard to the case, and that all the circumstances may not have been +considered. This caution with regard to the inaccurate representation of +facts, in natural history, is certainly extremely necessary; the relicts +of an elephant found in a mineral vein, is certainly a fact of that +kind, which should not be given as an example in geology without the +most accurate scientifical examination of the subject.] + +Here M. Pallas gives his reason for supposing those mountains primitive +or anterior to the operations of this globe as a living world; _first_, +because they have not, in general, marks of animals or plants; and that +it is doubtful if they ever properly contain those marks of organised +bodies; _secondly_, because many of those rocks have the appearance of +having suffered the effects of the most violent fire. Now, What are +those effects? Is it in their having been brought into a fluid state of +fusion. In that case, no doubt, they may have been much changed from the +original state of their formation; but this is a very good reason why, +in this changed state, the marks of organised bodies, which may have +been in their original constitution, should be now effaced. + +The _third_ reason for supposing those mountains primitive, is taken +from the metallic veins, which are found so plentifully in these masses. +Now, had these masses been the only bodies in this earth in which those +mineral veins were found, there might be some species of reason for +drawing the conclusion, which is here formed by our philosopher. But +nothing is so common (at least in England) as mineral veins in the +strata of the latest formation, and in those which are principally +formed of marine productions; consequently so far from serving the +purpose for which this argument was employed, the mineral veins in the +primitive mountains tend to destroy their originality, by assimilating +them in some respect with every other mass of strata or mountain upon +the globe. + +_Lastly_, M. Pallas here employs an argument taken from an appearance +for which we are particularly indebted to him, and by which the +arguments which have been already employed in denying the originality +of granite is abundantly confirmed. It has been already alleged, that +granite, porphyry, and whinstone, or trap, graduate into each other; but +here M. Pallas informs us that he has found the granite not only changed +into porphyry, but also into the other alpine compositions. How an +argument for the originality of these mountains can be established upon +those facts, I am not a little at a loss to conceive. + +The general mineralogical view of the Russian dominions, which we have, +in this treatise, may now be considered with regard to that distinction +made by naturalists, of primitive, secondary, and tertiary mountains, in +order to see how far the observations of this well informed naturalist +shall be found to confirm the theory of the earth which has been already +given, or not. + +The Oural mountains form a very long chain, which makes the natural +division betwixt Europe and Asia, to the north of the Caspian. If in +this ridge, as a centre of elevation, and of mineral operations, we +shall find the greatest manifestation of the violent exertion of +subterraneous fire, or of consolidating and elevating operations; and if +we shall perceive a regular appearance of diminution in the violence or +magnitude of those operations, as the places gradually recede from +this centre of active force; we may find some explanation of those +appearances, without having recourse to conjectures which carry no +scientific meaning, and which are more calculated to confound our +acquired knowledge, than to form any valuable distinction of things. Let +us consult M. Pallas how far this is the case, or not. + +After having told us that all those various alpine schisti, jaspers, +porphyries, serpentines, etc. in those mountains, are found mutually +convertible with granite, or graduating into each other, our author thus +continues, (p. 50). + +"On entrevoit de certaines loix a l'egard de l'arrangement respectif +de cet ordre secondaire d'anciennes roches, par tous les systemes de +montagnes qui appartiennent a l'Empire Russe. La chaine Ouralique, par +exemple, a du cote de l'Orient sur tout sa longueur, une tres-grande +abondance de schistes cornes, serpentins et talceux, riches en filons +de cuivre, qui forment le principal accompagnement du granite, et en +jaspres de diverses couleurs plus exterieurs et souvent comme entrelaces +avec les premiers, mais formant des suites de montagnes entieres, et +occupant de tres-grands espaces. De ce meme cote, il y parait beaucoup +de quartz en grandes roches toutes pures, tant dans la principale chaine +que dans le noyau des montagnes de jaspre, et jusques dans la plaine. +Les marbres spateux et veines, percent en beaucoup d'endroits. La +plupart de ces especes ne paraissent point du tout a la lisiere +occidentale de la chaine, qui n'est presque que de roche melangee de +schistes argileux, alumineux, phlogistique, etc. Les filons des mines +d'or melees, les riches mines de cuivre en veines et chambrees, les +mines de fer et d'aimant par amas et montagnes entieres, sont l'apanage +de la bande schisteuse orientale; tandis que l'occidentale n'a pour elle +que des mines de fer de depots, et se montre generalement tres-pauvre en +metaux. Le granit de la chaine qui borde la Siberie, est recouvert du +cote que nous connaissons de roches cornees de la nature des pierres a +fusil, quelquefois tendant a la nature d'un grais fin et de schistes +tres-metallieres de differente composition. Le jaspre n'y est qu'en +filons, ou plans obliques, ce qui est tres-rare pour la chaine +Ouralique, et s'observe dans la plus grande partie de la Siberie, a +l'exception de cette partie de sa chaine qui passe pres de la mer +d'Okhotsk, ou le jaspre forme derechef des suites de montagnes, ainsi +que nous venons de le dire des monts Ourals; mais comme cette roche +tient ici le cote meridionale de la chaine Siberienne, et que nous +ne lui connaissons point ce cote sur le reste de sa longueur, il se +pourrait que le jaspre y fut aussi abondant. Il faudrait, au reste, bien +plus de fouilles et d observations pour etablir quelque chose de certain +sur l'ordre respectif qu'observent ces roches." + +I would now ask, if in all this account of the gradation of rock from +the Oural mountains to the sandy coast of the Baltic, there is to be +observed any clear and distinctive mark of primitive, secondary, and +tertiary, mountains, farther than as one stratum may be considered as +either prior or posterior to another stratum, according to the order of +superposition in which they are found. We have every where evident marks +of the formation of strata by materials deposited originally in water; +for the most part, there is sufficient proof that this water in which +those materials had been deposited was the sea; we are likewise assured +that the operations of this living world producing animals, must +have, for a course of time, altogether inconceivably been exerted, +in preparing materials for this mass; and, lastly, from the changed +constitution of those masses, we may infer certain mineral operations +that melt the substance and alter the position of those horizontal +bodies. Such is the information which we may collect from this mineral +description of the Russian Dominions. + +If we compare some of the Oural mountains with the general strata of +the Russian plains, then, as to the contained minerals, we may find a +certain diversity in those two places; at the same time, no greater +perhaps than may be found betwixt two different bodies in those same +plains, for example, chalk and flint. But when we consider those bodies +of the earth, or solid strata of the globe, in relation to their proper +structure and formation, we surely can find in this description nothing +on which may be founded any solid opinion with regard to a different +original, however important conclusions may perhaps be formed with +regard to the operations of the globe, from the peculiar appearances +found in alpine. + +From this detail of what is found in the Oural mountains, and in the +gradation of country from those mountains to the plains of Russia, we +have several facts that are worthy of observation. First extensive +mountains of jasper. I have a specimen of this stone; it is striped red +and green like some of our marly strata. It has evidently been formed of +such argillaceous and siliceous materials, not only indurated, so as to +lose its character, as an argillaceous stone, but to have been brought +into that degree of fusion which produces perfect solidity. Of the same +kind are those hornstein rocks of the nature of flint, sometimes tending +to the nature of a fine sandstone. Here is the same induration of +sandstone by means of fusion, that in the argillaceous strata has +produced jasper. But oblique veins of jasper are represented as +traversing these last strata; now this is a fact which is not +conceivable in any other way, than by the injection or transfusion of +the fluid jasper among those masses of indurated strata. + +All this belongs to the east side of the mountains. On the west, again, +we find the same species of strata; only these are not changed to such a +degree as to lose their original character or construction, and thus to +be termed differently in mineralogy. + +Our author then proceeds. (p. 53.) + +"Nous pourrons parler plus decisivement sur les _montagnes secondaires +et tertiaires_ de l'Empire, et c'est de celles-la, de la nature, de +l'arrangement et du contenu de leurs couches, des grandes inegalites et +de la forme du continent d'Europe et d'Asie, que l'on peut tirer avec +plus de confiance quelques lumieres sur les changemens arrives aux +terres habitables. Ces deux ordres de montagnes presentent la chronique +de notre globe la plus ancienne, la moins sujette aux falsifications, et +en meme-tems plus lisible que le caractere des chaines primitives; +ce font les archives de la nature, anterieures aux lettres et aux +traditions les plus reculees, qu'il etoit reserve a notre siecle +observateur de feuiller, de commenter, et de mettre au jour, mais que +plusieurs siecles apres le notre n'epuiseront pas. + +"Dans toute l'etendue de vastes dominations Russes, aussi bien que +dans l'Europe entiere, les observateurs attentifs ont remarque +que generalement la band schisteuse des grandes chaines se trouve +immediatement recouverte ou cottee par la _bande calcaire_. Celle-ci +forme deux ordres de montagnes, tres-differentes par la hauteur, la +situation de leurs couches, et la composition de la pierre calcaire qui +les compose; difference qui est tres-evidente dans cette bande calcaire +qui forme la lisiere occidentale de toute la chaine Ouralique, et dont +le plan s'etend par tout le plat pays de la Russie. L'on observerait +la meme chose a l'orient de la chaine, et dans toute l'etendue de la +Siberie, si les couches calcaires horizontales n'y etaient recouvertes +par les depots posterieures, de facon qu'il ne parait a la surface que +les parties les plus faillantes de la bande, et si ce pays n'etoit trop +nouvellement cultive et trop peu exploite par des fouilles et autres +operations, que des hommes industrieux ont pratique dans les pays +anciennement habites. Ce que je vais exposer sur les deux ordres de +montagnes calcaires, se rapportera donc principalement a celles qui sont +a l'occident de la chaine Ouralique. + +"Ce cote de la dite chaine consiste sur cinquante a cent verstes de +largeur, de roche calcaire solide, d'un grain uni, qui tantot ne +contient aucune trace de productions marines, tantot n'en conserve +que des empreintes aussi legeres qu'eparses. Cette roche s'eleve en +montagnes d'une hauteur tres-considerable, irregulieres, rapides, et +coupees de vallons escarpes. Ses couches, generalement epaisses, ne sont +point de niveau, mais tres-inclinees a l'horizon, paralleles, pour la +plupart, a la direction de la chaine, qui est aussi ordinairement celle +de la bande schisteuse;--au lieu que du cote de l'orient les couches +calcaires sont au sens de la chaine en direction plus ou moins +approchante de l'angle droite. L'on trouve dans ces hautes montagnes +calcaires de frequentes grottes et cavernes tres-remarquables, tant +par leur grandeur que par les belles congelations et crystallizations +stalactiques dont elles s'ornent. Quelques-unes de ces grottes ne +peuvent etre attribuees qu'a quelque bouleversement des couches; +d'autres semblent devoir leur origine a l'ecoulement des sources +souterraines qui ont amolli, ronge et charrie une partie de la roche qui +en etoit susceptible. + +"En s'eloignant de la chaine, on voit les couches calcaires s'aplanir +assez rapidement, prendre une position horizontale, et devenir +abondantes en toute forte de coquillages, de madrepores, et d'autres +depouilles marines. Telles on les voit par-tout dans les vallees les +plus basses qui se trouvent aux pieds des montagnes (comme aux environs +de la riviere d'Oufa); telles aussi, elles occupent tout l'etendue de la +grande Russie, tant en collines qu'en plat pays; solides tantot et comme +semees de productions marines; tantot toutes composees de coquilles et +madrepores brisees, et de ce gravier calcaire qui se trouve toujours sur +les parages ou la mer abonde en pareilles productions; tantot, enfin, +dissoutes en craie et en marines, et souvent entremelees de couches de +gravier et de cailloux roules." + +How valuable for science to have naturalists who can distinguish +properly what they see, and describe intelligibly that which they +distinguish. In this description of the strata, from the chain of +mountains here considered as primitive, to the plains of Russia, which +are supposed to be of a tertiary formation, our naturalist presents us +with another species of strata, which he has distinguished, on the one +hand, in relation to the mountains at present in question, and on the +other, with regard to the strata in the plains, concerning which there +is at present no question at all. Now, let us see how these three things +are so connected in their nature, as to form properly the contiguous +links of the same chain. + +The primary and tertiary masses are bodies perfectly disconnected; +and, without a medium by which they might be approached, they would be +considered as things differing in all respects, consequently as having +their origins of as opposite a nature as are their appearances. But the +nature and formation of those bodies are not left in this obscurity; +for, the secondary masses, which are interposed, participate so +precisely of what is truly opposite and characteristic in the primary +and tertiary masses, that it requires nothing more than to see this +distinction of things in its true light, to be persuaded, that in those +three different things we may perceive a certain gradation, which +here takes place among the works of nature, and forms three steps +distinguishable by a naturalist, although in reality nothing but the +variable measure of similar operations. + +We are now to assimilate the primary and tertiary masses, which are so +extremely different, by means of the secondary masses, which is the +mean. The primary and tertiary differ in the following respects: The one +of these contains the relicts of organised bodies which are not observed +in the other. But in the species containing these distinguishable +bodies, the natural structure and position of the mass is little +affected, or not so much as to be called into doubt. This, however, is +not the case with the other; the species in which organised bodies do +not appear, is in general so indurated or consolidated in its structure, +and changed in its position, that this common origin of those masses is +by good naturalists, who have also carefully examined them, actually +denied. Now, the secondary masses may be considered, not only as +intermediate with respect to its actual place, as M. Pallas has +represented it, but as uniting together the primary and tertiary, or as +participating of the distinguishing characters of the other two. It +is homologated with the primitive mountains, in the solidity of its +substance and in the position of its strata; with the tertiary species, +again, in its containing marks of organised bodies. How far this view +of things is consistent with the theory of the earth now given, is +submitted to the consideration of the unprejudiced. + +Let us see what our learned author has said farther on this subject, +(page 65). + +"Je dois parler d'un ordre de montagnes tres-certainement posterieur aux +couches marines, puisque celles-ci, generalement lui servent de base. +On n'a point jusqu'ici observe une suite de ces _montagnes tertiaires_, +effet des catastrophes les plus modernes de notre globe, si marquee +et si puissante, que celle qui accompagne la chaine Ouralique ou cote +occidentale fur tout la longueur. Cette suite de montagnes, pour la +plupart composees de grais, de marnes rougeatres, entremelees de couches +diversement mixtes, forme une chaine par-tout separee par une vallee +plus ou moins large de la bande de roche calcaire, dont nous avons +parle. Sillonnee et entrecoupee de frequens vallons, elles s'eleve +souvent a plus de cent toises perpendiculaires, se repand vers les +plaines de la Russie en trainees de collines, qui separent les rivieres, +en accompagnant generalement la rive boreale ou occidentale, et degenere +enfin en deserts sableux qui occupent de grands espaces, et s'etendent +surtout par longues bandes paralleles aux principales traces qui suivent +les cours des rivieres. La principale force de ces montagnes tertiaires +est plus pres de la chaine primitive par-tout le gouvernement +d'Orenbourg et la Permie, ou elle consiste principalement en grais, et +contient un fond inepuisable de mines de cuivre sableuses, argileuses, +et autres qui se voient ordinairement dans les couches horizontales. +Plus loin, vers la plaine, sont des suites de collines toutes marneuses, +qui abondent autant en pierres gypseuses, que les autres en minerais +cuivreux. Je n'entre pas dans le detail de celles-ci, qui indiquent +sur-tout les sources salines; mais je dois dire des premieres, qui +abondent le plus et dont les plus hautes elevations des plaines, meme +celle de Moscou, sont formees, qu'elles contiennent tres-peu de traces +de productions marines, et jamais des amas entiers de ces corps, tels +qu'une mer reposee pendant des siecles de suite a pu les accumuler dans +les bancs calcaires. Rien, au contraire, de plus abondant dans ces +montagnes de grais stratifie sur l'ancien plan calcaire, que des troncs +d'arbres entieres et des fragmens de bois petrifie, souvent mineralise +par le cuivre ou le fer; des impressions de troncs de palmires, de +tiges de plantes, de roseau, et de quelques fruits etrangers; enfin des +ossemens d'animaux terrestres, si rares dans les couches calcaires. Les +bois petrifies se trouvent jusques dans les collines de sable de la +plaine; l'on en tire, entr'autres, des hauteurs sablonneuses aux +environs de Sysran sur la Volga, changes en queux tres-fin, qui a +conserve jusqu'a la texture organique du bois, et remarquables sur-tout +par les traces tres-evidentes de ces vers rongeurs qui attaquent les +vaisseaux, les pilotis et autres bois trempes dans la mer, et qui sont +proprement originaires de la mer des Indes." + +This philosopher has now given us a view of what, according to the +present fashion of mineral philosophy, he has termed _montagnes +primitives, secondaires, et tertiaires_. The first consists in masses +and strata, much indurated and consolidated, and greatly displaced in +their position; but the character of which is chiefly taken from this, +that they contain not any visible mark of animal or vegetable bodies. + +The second are formed in a great measure of marine productions, are +often no less consolidated than those of the first class, and frequently +no less changed in their natural shape and situation. + +The third again have for character, according to this learned theorist, +the containing of those organised bodies which are proper to the earth, +instead of those which in the second class had belonged to the sea; +in other respects, surely there is no essential difference. It is not +pretended that these tertiary strata had any other origin, than that of +having been deposited in water; it is not so much as suspected, that +this water had been any other than that of the sea; the few marine +bodies which M. Pallas here acknowledges, goes at least to prove this +fact: and with regard to the mineral operations which had been employed +in consolidating those water formed strata, it is impossible not to be +convinced that every effect visible in the other two are here also to be +perceived. + +From this view of mineral bodies, taken from the extensive observations +of the Russian dominions, and from the suppositions of geologists in +relation to those appearances, we should be led to conclude that the +globe of this earth had been originally nothing but an ocean, a world +containing neither plant nor animal to live, to grow and propagate its +species. In following a system founded on those appearances, we must +next suppose, that to the sterile unorganised world there had succeeded +an ocean stored with fish of every species. Here it would be proper to +inquire what sustained those aquatic animals; for, in such a system as +this, there is no provision made for continuing the life even of the +individuals, far less of feeding the species while, in an almost +infinite succession of individuals, they should form a continent of land +almost composed of their _exuviae_. + +If fish can be fed upon water and stone; if siliceous bodies can, by +the digesting powers of animals, be converted into argillaceous and +calcareous earths; and if inflammable matter can be prepared without the +intervention of vegetable bodies, we might erect a system in which this +should be the natural order of things. But to form a system in direct +opposition to every order of nature that we know, merely because we may +suppose another order of things different from the laws of nature which +we observe, would be as inconsistent with the rules of reasoning in +science, by which the speculations of philosophy are directed, as it +would be contrary to common sense, by which the affairs of mankind are +conducted. + +Still, however, to pursue our visionary system, after a continent had +been formed from the relicts of those animals, living, growing, and +propagating, during an indefinite series of ages, plants at last are +formed; and, what is no less wonderful, those animals which had formed +the earth then disappear; but, in compensation, we are to suppose, I +presume, that terrestrial animals began. Let us now reason from those +facts, without either constraining nature, which we know, or forming +visionary systems, with regard to things which are unknown. It would +appear, that at one period of time, or in one place, the matter of the +globe may be deposited, in strata, without containing any organised +bodies; at another time, or in another place, much animal matter may be +deposited in strata, without any vegetable substance there appearing; +but at another period, or at another time, strata may be formed with +much vegetable matter, while there is hardly to be observed any animal +body. What then are we to conclude upon the whole? That nature, forming +strata, is subject to vicissitudes; and that it is not always the same +regular operation with respect to the materials, although always forming +strata upon the same principles. Consequently, upon the same spot in +the sea, different materials may be accumulated at different periods of +time, and, conversely, the same or similar materials may be collected in +different places at the same time. Nothing more follows strictly from +the facts on which we now are reasoning; and this is a conclusion which +will be verified by every appearance, so far as I know. + +Of this I am certain, that in a very little space of this country, in +many places, such a course of things is to be perceived. Nothing so +common as to find alternated, over and over again, beds of sand-stone +without animal bodies, beds of coal and schistus abounding with +vegetable bodies, beds of lime-stone formed of shells and corals, and +beds or particular strata of iron-stone containing sometimes vegetable +sometimes animal bodies, or both. Here, indeed, the strata are most +commonly inclined; it is seldom they are horizontal; consequently, as +across the whole country, all the strata come up to the day, and may be +seen in the beds of our rivers, we have an opportunity of observing that +great variety which is in nature, and which we are not able to explain. +This only is certain, from what we see, that there is nothing formed +in one epoch of nature, but what has been repeated in another, however +dissimilar may be the operations which had intervened between those +several epochs. + +It must not be alleged, that the heights of the Oural mountains, or the +hardness of their rocks, make an essential distinction between them +and the argillaceous or arenaceous strata of the plains; solidity and +hardness, as well as changes in their height and natural position, has +been superinduced in operations posterior to the collection of those +masses,--operations which may be formed in various degrees, even in the +different parts of the same mass. If this is the case, there can be no +difficulty in conceiving a stratum, which appears to be argillaceous +or marly in the plains, to be found jasper in the Oural mountains. But +there is nothing in the Oural mountains, that may not be found some +where or other in the plains, although the soft and easily decomposing +argillaceous strata be not found upon the Oural mountains, or the Alps, +for this reason, that had those mountains been formed of such materials, +there had not been a mountain there at this day. + +But surely the greatest possible error, with regard to the philosophy of +this earth, would be to confound the sediment of a river with the strata +of the globe; bodies deposited upon the surface of the earth, with those +sunk at the bottom of the sea; and things which only form the travelled +or transported soil, with those which constitute the substratum or the +solid earth. How far M. Pallas has committed this oversight, I leave +others to determine. After mentioning those strata in which wood is +found petrified, and metallic minerals formed, he thus proceeds, (page +69). + +"Dans ces memes depots sableux et souvent limoneux, gisent les restes +des grands animaux de l'Inde: ces ossemens d'elephans, de rhinoceros, de +buffles monstrueux, dont on deterre tous les jours un si grand nombre, +et qui font l'admiration des curieux. En Siberie, ou l'on a decouvert le +long de presque toutes les rivieres ces restes d'animaux etrangers, +et l'ivoire meme bien conserve en si grande abondance, qu'il forme un +article de commerce, en Siberie, dis je, c'est aussi la couche la plus +moderne de limon sablonneux qui leur sert de sepulture, et nulle part +ces monumens etrangers sont si frequens, qu'aux endroits ou la grande +chaine, qui domine surtout la frontiere meridionale de la Siberie, offre +quelque depression, quelque ouverture considerable. + +"Ces grands ossemens, tantot epars tantot entasses par squelettes, +et meme par hecatombes, consideree dans leurs sites naturels, m'ont +sur-tout convaincu de la realite d'un deluge arrive sur notre terre, +d'une catastrophe, dont j'avoue n'avoir pu concevoir la vraisemblance +avant d'avoir parcouru ces places, et vu, par moi-meme, tout ce qui peut +y servir de preuve a cet evenement memorable[24]. Une infinite de ces +ossemens couches dans des lits meles de petites tellines calcinees, d'os +de poissons, de glossopetres, de bois charges d'ocre, etc. prouve deja +qu'ils ont ete transportes par des inondations. Mais la carcasse d'un +rhinoceros, trouve avec sa peau entiere, des restes de tendons, de +ligamens, et de cartilages, dans les terres glacees des bords du +Viloui, dont j'ai depose les parties les mieux conservees au cabinet de +l'Academie, forme encore une preuve convaincante que ce devait etre +un mouvement d'inondation des plus violens et des plus rapides, qui +entraina jadis ces cadavres vers nos climats glaces, avant que la +corruption eut le tems, d'en detruire les parties molles. Il seroit a +souhaiter qu'un observateur parvint aux montagnes qui occupent l'espace +entre les fleuves Indighirka et Koylma ou selon le rapport des +chasseurs, de semblables carcasses d'elephans et d'autres animaux +gigantesques encore revetues de leurs peaux, ont ete remarquees a +plusieurs reprises." + +[Note 24: Voyez le Memoire, imprime dans le XVII. volume des nouveaux +Commentaires de l'Academie Imperiale de Petersbourgh.] + +The question here turns upon this, Are the sea shells and glossopetrae, +which are thus found deposited along with those skeletons, in their +natural state, or are they petrified and mineralised. If the productions +of the sea shall here be found collected along with bodies belonging to +the surface of the earth, and which had never been within the limits of +the sea, this would surely announce to us some strange catastrophe, +of which it would be difficult, perhaps, to form a notion; if, on the +contrary, those marine productions belong to the solid strata of the +earth, in the resolution or decay of which they had been set at liberty, +and were transported in the floods, our author would have no reason from +those appearances to conclude, there had existed any other deluge than +those produced by the waters of the land[25]. + +[Note 25: Since writing this, I find my doubts in a great measure +resolved, in reading M. Pallas's Journal, translated from the German by +M. Gauthier de la Peyronie. What I had suspected is, I think, confirmed +in the distinct account which M. Pallas has given of those occasions +in which the bones of land animals and marine objects are found buried +together. The marine objects are mineralised; consequently, they have +proceeded from the decomposition of the solid strata; and, having been +travelled in the running water of the surface of the earth, they must +have been deposited in those beds of rivers, which now are dry, alongst +with the bones, or the entire bodies of terrestrial animals, the remains +of which are now found there. This argument, from the state of those +marine bodies will not be allowed, perhaps by the generality of +mineralists, who attribute to the operations of water every species of +petrifaction or mineralisation; but, until some species of proof be +given with regard to the truth of that theory, which vulgar error first +suggested, I must reason from a theory, in proof of which I have given +clear examples, and, I think, irrefragable arguments, which shall be +more and more illustrated. Thus may be removed the necessity of a +general deluge, or any great catastrophe, in order to bring together +things so foreign to each other; but at the same time we would ascertain +this fact, That formerly the Elephant and Rhinoceros had lived in +Siberia. (See Voyage de Pallas, Tom. II. p. 377 and 403.)] + +Having thus endeavoured to remove this prevailing prejudice, of there +being primitive parts in this earth, parts of which the composition and +constitution are not to be explained upon the principles of natural +philosophy, it will be proper to inquire, how far there may be in the +theory, which has now been given, principles by which may be explained +those appearances that have led natural philosophers to form +conclusions, of there being in this earth parts whose origin may not be +traced; and of there being parts whose origin may not be explained upon +the same principles which apply so well to all the rest. + + + +CHAP. V. + +Concerning that which may be termed the Primary Part of the Present +Earth. + +In the present theory, it is maintained, that there is no part of the +earth which has not had the same origin, so far as this consists in that +earth being collected at the bottom of the sea, and afterwards produced, +as land, along with masses of melted substances, by the operation of +mineral causes. But, though all those things be similar, or equal, as to +the manner of their production, they are far from being so with regard +to the periods of their original composition, or to the subsequent +operations which they may have undergone. + +There is a certain order established for the progress of nature, for the +succession of things, and for the circulation of matter upon the surface +of this globe; and, the order of time is associated with this change of +things. But it is not in equal portions that time is thus combined with +dissimilar things, nor always found, in our estimation, as equally +accompanying those which we reckon similar. The succession of light and +darkness is that which, in those operations, appears to us most steady; +the alternation of heat and cold comes next, but not with equal +regularity in its periods. The succession of wet and dry upon the +surface of the earth, though equally the work of nature and the effect +of regular causes, is often to us irregular, when we look for equal +periods in the course of things which are unequal. It is by equalities +that we find order in things, and we wish to find order every where. + +The present object of our contemplation is the alternation of land +and water upon the surface of this globe. It is only in knowing this +succession of things, that natural appearances can be explained; and +it is only from the examination of those appearances, that any certain +knowledge of this operation is to be obtained. But how shall we acquire +the knowledge of a system calculated for millions, not of years only, +nor of the ages of man, but of the races of men, and the successions of +empires? There is no question here with regard to the memory of man, of +any human record, which continues the memory of man from age to age; we +must read the transactions of time past, in the present state of natural +bodies; and, for the reading of this character, we have nothing but +the laws of nature, established in the science of man by his inductive +reasoning. + +It has been in reasoning after this manner, that I have endeavoured to +prove, that every thing which we now behold, of the solid parts of this +earth, had been formerly at the bottom of the sea; and that there is, in +the constitution of this globe, a power for interchanging sea and land. +If this shall be admitted as a just view of the system of this globe, +we may next examine, how far there are to be found any marks of certain +parts of our earth having more than once undergone that change of +posture, or vicissitude of things, and of having had reiterated +operations of the mineral kingdom changing their substance, as well as +altering their positions in relation to the atmosphere and sea. + +Besides the gradual decay of solid land, exposed to the silent +influences of the atmosphere, and to the violent operations of the +waters moving upon the surface of the earth, there is a more sudden +destruction that may be supposed to happen sometimes to our continents +of land. In order to see this, it must be considered, that the +continents of our earth are only raised above the level of the sea by +the expansion of matter, placed below that land, and rarified in that +place: We may thus consider our land as placed upon pillars, which may +break, and thus restore the ancient situation of things when this land +had been originally collected at the bottom of the ocean. It is not here +inquired by what mechanism this operation is to be performed; it is +certainly by the exertion of a subterranean power that the land is +elevated from the place in which it had been formed; and nothing is more +natural than to suppose the supports of the land in time to fail, or be +destroyed in the course of mineral operations which are to us unknown. +In that case, whatever were remaining of that land, which had for +millions of ages past sustained plants and animals, would again be +placed at the bottom of the sea; and strata of every different species +might be deposited again upon that mass, which, from an atmospheric +situation, is now supposed to be lower than the surface of the sea. + +Such a compound mass might be again resuscitated, or restored with the +new superincumbent strata, consolidated in their texture and inclined in +their position. In that case, the inferior mass must have undergone a +double course of mineral changes and displacement; consequently, the +effect of subterranean heat or fusion must be more apparent in this +mass, and the marks of its original formation more and more obliterated. + +If, in examining our land, we shall find a mass of matter which had been +evidently formed originally in the ordinary manner of stratification, +but which is now extremely distorted in its structure, and displaced in +its position,--which is also extremely consolidated in its mass, and +variously changed in its composition,--which therefore has the marks +of its original or marine composition extremely obliterated, and many +subsequent veins of melted mineral matter interjected; we should then +reason to suppose that here were masses of matter which, though not +different in their origin from those that are gradually deposited at the +bottom of the ocean, have been more acted upon by subterranean heat and +the expanding power, that is to say, have been changed in a greater +degree by the operations of the mineral region. If this conclusion shall +be thought reasonable, then here is an explanation of all the peculiar +appearances of the alpine schistus masses of our land, those parts which +have been erroneously considered as primitive in the constitution of the +earth. + +We are thus led to suppose, that some parts of our earth may have +undergone the vicissitudes of sea and land more than once, having been +changed from the summit of a continent to the bottom of the sea, and +again erected, with the rest of that bottom, into the place of land. In +that case, appearances might be found to induce natural philosophers to +conclude that there were in our land primary parts, which had not the +marine origin which is generally to be acknowledged in the structure +of this earth; and, by finding other masses, of marine origin, +superincumbent upon those primary mountains, they might make strange +suppositions in order to explain those natural appearances. + +Let us now see what has been advanced by those philosophers who, though +they term these parts of the earth _primordial_, and not _primitive_, at +the same time appear to deny to those parts an origin analogous to that +of their secondary mountains, or strata that are aquiform in their +construction. + +M. de Luc, after having long believed that the strata of the Alps had +been formed like those of the low countries, at the bottom of the sea, +gives an account of the occasion by which he was first confirmed in the +opposite opinion.[26] Like a true philosopher, he gives us the reason of +this change. + +[Note 26: Lettres Physique et Morales sur l'Histoire de la Terre, tom. +2. pag. 206.] + +"Ce fut une espece de _montagne_ tres commune, et que j'avois souvent +examinee qui dessilla mes yeux. La pierre qui la compose est de +la classe appellee _schiste_; son caractere generique est d'etre +_feuilletee_; elle renferme _l'ardoise_ dont on couvre les toits. Ces +_feuillets_ minces, qu'on peut prendre pour des _couches_, et qui le +font en effet dans quelques pierres de ce genre, rappelloient toujours +l'idee vague de depots des eaux. Mais il y a des masses dont la +composition est plutot par fibres que par feuillets, et dont le moellon +ressemble aux copeaux de bois d'un chantier. Le plus souvent aussi les +feuillets sont situes en toute suite de sens dans une meme _montagne_, +et quelquefois meme verticalement, Enfin il s'en trouve de si tortilles, +qu'il est impossible de les regarder comme des depots de l'eau. + +"Ce fut donc cette espece de montagne qui me persuada la premiere +que toutes les montagnes n'avoient pas une meme origine. Le lieu ou +j'abjurai mon erreur, etoit un de ces grands _chantiers_ petrifies, qui, +par la variete du tortillement, et des zig-zags des fibres du moellon +qui le composoit, attira singulierement mon attention. C'etoit un sort +grand talus qui venoit d'une face escarpee; j'y montai pour m'approcher +du rocher, et je remarquai, avec etonnement, des multitudes de paquets +enchevetres les uns dans les autres, sans ordre ni direction fixe; les +uns presqu'en rouleaux; les autres en zig-zag; et meme ce qui, separe de +la montagne, eut peu etre pris pour des _couches_, le trouvoit incline +de toute maniere dans cette meme face de rocher. _Non_, me dis-je alors +a moi-meme; _non, l'eau n'a pu faire cette montagne.... Ni celle-la +donc_, ajoutai-je en regardant ailleurs.... _Et pourquoi mieux celle-la? +Pourquoi toutes les montagnes devroient-elles etre le produit des eaux, +seulement parce qu'il y en a quelques-unes qui annoncent cette origine_? +En effet, puis qu'on n'a songe aux eaux, comme cause des montagnes, +que par les preuves evidentes que quelques-unes offroient de cette +formation; pourquoi etendre cette consequence a toutes, s'il y en +a beaucoup qui manquent de ces caracteres? C'est comme le dit Mr. +d'Alembert, qu'on generalise ses premieres remarques l'instant d'apres +qu'on ne remarquoit rien." + +Science is indebted to this author for giving us so clear a picture +of natural appearances, and of his own reasoning upon those facts, in +forming his opinion; he thus leads astray no person of sound judgment, +although he may be in error. The disposition of things in the present +case are such, that, reasoning from his principles, this author could +not see the truth; because he had not been persuaded, that aquiform +strata could have been so changed by the chemical power of fusion, and +the mechanical force of bending while in a certain state of softness. + +But though, in this case, the reasoning of this philosopher is to be +justified, so far as he proceeded upon principles which could not lead +him to the truth, his conduct is not so irreproachable in applying them +to cases by which their fallacy might have been detected. This author +acknowledges calcareous strata to be aquiform in their original; but, +in those mountains which he has so much examined, he will find those +aquiform bodies have undergone the same species of changes, which made +him conclude that those schistus mountains had not been truly aquiform, +as he at first had thought them. This would have led him to reason back +upon his principles, and to say, _If one species of strata may be thus +changed in its texture, and its shape, may not another be equally so? +Therefore, may not the origin of both be similar_? + +But least I should do injustice to this author, to whom we are indebted +for many valuable observations in natural history, I shall transcribe +what he has said upon the subject, being persuaded that my readers will +not think this improper in me, or impertinent to the argument. + +"Quand nous fumes une fois persuades que la mer n'avoit pas fait +toutes les _montagnes_, nous entreprimes de decouvrir les caracteres +distinctifs de celles qui lui devoient leur origine; et s'il etoit, par +exemple, des matieres qui leur fussent propres. Mais nous y trouvames +les memes difficultes qu'on rencontre dans tout ce qu'on veut classer +dans la nature. On peut bien distinguer entr'elles les choses qui +ont fortement l'empreinte de leur classe; mais les confins echappent +toujours. + +"C'est la, pour le dire en passant, ce qui a pu conduire quelques +philosophes a imaginer cette _chaine des etres_ ou ils supposent, +que, de la pierre a l'homme et plus haut, les nuances sont reellement +imperceptibles. Comme si, quoique les limites soyent cachees a nos sens, +notre intelligence ne nous disoit pas, qu'il y a un _saut_, une distance +meme infinie, entre le plus petit degre d'organization _propageante_, +et la matiere unie par la simple cohesion: entre le plus petit degre de +_sensibilite_, et la matiere insensible: entre la plus petite capacite +d'observer et de transmettre ses observations, et l'instinct constamment +le meme dans l'espece. Toutes ces differences tranchees existent dans la +nature; mais notre incapacite de rien connoitre a fond, et la necessite +ou nous sommes de juger de tout sur des apparences, nous fait perdre +presque toutes les limites, parce que sur ces bords, la plupart des +phenomenes sont equivoques. Ainsi la plante nous paroit se rapprocher de +la pierre, mais n'en approche jamais reellement. + +"On eprouve la meme difficulte a classer les montagnes; et quoique +depuis quelque tems plusieurs naturalistes ayent aussi observe qu'elles +n'ont pas toutes la meme origine, je ne vois pas qu'on soit parvenu a +fixer des caracteres infaillibles, pour les placer surement toutes dans +leurs classes particulieres. + +"Apres avoir examine attentivement cet objet, d'apres les phenomenes que +j'ai moi-meme observes, et ce que j'ai appris par les observations des +autres; j'ai vu que c'etoit la un champ tres vaste, quand on vouloit +l'embrasser en entier, et trop vaste pour moi, qui n'etoit pas libre d'y +consacrer tout le tems qu'il exige. Je me suis donc replie sur mon objet +principal, savoir _la cause qui a laisse des depouilles marines dans nos +continens_, et l'examen des hypotheses sur cette matiere. + +"Les phenomenes ainsi limites, se reduisent a ceci: qu'il y a dans nos +continens des montagnes visiblement formees par des _depots successifs +de la mer_ et a l'egard des quelles il n'y a besoin de rien imaginer, si +ce n'est la maniere dont elles en sont sorties: qu'il y en a d'autres au +contraire, qui ne portent aucun des caracteres de cette cause, et qui, +si elles ont ete produites dans la _mer_, doivent etre l'effet de toute +autre cause que de simples depots successifs, et avoir meme precede +l'existence des animaux marins. J'abandonne donc les classes confuses +ou ces caracteres sont equivoques, jusqu'a ce qu'elles servent a fonder +quelque hypothese; ayant assez de ces deux classes tres distinctes pour +examiner d'apres elles tous les systemes qui me sont connus. + +"La ou ces deux classes de montagnes sont melees, on remarque que celles +qui sont formees par _couches_, et qui renferment des _corps marins_, +recouvrent souvent celles de l'autre classe, mais n'en sont jamais +recouvertes. On a donc naturellement conclu, que lors meme que la _mer_ +auroit en quelque part a la formation des montagnes ou l'on ne reconnoit +pas son caractere, celles auxquelles elle a travaille seule, en enlevant +des matieres dans certaines parties de son fond et les deposant dans +d'autres, font au moins les dernieres formees. On les a donc nommees +_secondaires_, et les autres _primitives_. + +"J'adopterai la premiere de ces expressions; car c'est la meme qui nous +etoit venu a l'esprit a mon frere, et a moi longtemps avant que nous +l'eussions vue employer; mais je substituerai celle de _primordiales a_ +_primitives_ pour l'autre classe de _montagnes_, afin de ne rien decider +sur leur origine. Il est des _montagnes_, dont jusqu'a present on n'a pu +demeler la cause: voila le fait. Je ne dirai donc pas qu'elles ont +ete creees ainsi, parce qu'en physique je ne dois pas employer des +expressions sur lesquelles on ne s'entend pas. Sans doute cependant, +que l'histoire naturelle ni la physique ne nous conduisent nullement a +croire que notre globe ait existe de toute eternite; et lorsqu'il prit +naissance, il fallut bien que la matiere qui le composa fut de quelque +nature, ou sous quelque premiere forme integrante. Rien donc jusqu'ici +n'empeche d'admettre que ces _montagnes_ que je nommerai _primordiales_, +ne soient reellement _primitives_; je penche meme pour cette opinion +a l'egard de quelques unes. Mais il y a une tres grande variete +entr'elles; et quoiqu'elles soyent toutes egalement exclues de la classe +_secondaire_, elles ne sont pas toutes semblables: il y en a meme un +grand nombre dont les matieres ont une certaine configuration qui semble +annoncer qu'elles ayent ete molles et durcies ensuite, quoique par +une toute autre cause que celle qui a agi pour former les montagnes +secondaires." + +Here I would beg leave to call the attention of philosophers to this +observation of a naturalist who explains all petrification, and the +consolidation of strata by aqueous infiltration. If he has here found +reason to conclude that, in those primordial parts of the earth, there +are a great number which, from their present configuration, must have +been in a soft state and then hardened, and this by a quite different +cause from that which he supposes had produced the consolidation and +hardness of the secondary parts; this is entering precisely into my +views of the subject, in ascribing all the consolidation of the earth, +whether primary or secondary, to one general cause, and in tracing this +cause, from its effects, to be no other than the fusion of those bodies. +It must be evident, that if this philosopher has seen good reason for +concluding such a softening cause, which had operated upon the primary +parts, to be quite different from that which he ascribes to the +consolidation of the secondary, which is the effect of water, it must +then, I say, be evident that the softening cause of the primary parts, +if not heat, by which every degree of fusion may be produced, must be an +occult cause, one which cannot be admitted into natural philosophy. + +By thus choosing to consider mountains as of two distinct kinds, one +aquiform which is understood, and the other primordial which is not to +be known, we supersede the necessity of reconciling a theory with many +appearances in nature which otherwise might be extremely inconvenient +to our explanation, if not inconsistent with our system. Our author no +doubt has thus relieved himself from a considerable difficulty in the +philosophy of this earth, by saying here is a great part which is not +to be explained. But I would beg leave to observe, that this form of +discussion, with regard to a physical subject, is but a mere confession +of our ignorance, and has no tendency to clear up another part of the +subject of which one treats, however it may impress us with a favourable +opinion of the theorist, in allowing him all the candour of the +acknowledgement. + +The general result of the reasoning which we now have quoted, and what +follows in his examination, seems to terminate in this; that there are +various different compositions of mountains which this author cannot +allow to be the production of the sea; but it is not upon account of +the matter of which they are formed, or of the particular mixture and +composition of those species of matter, of which the variety is almost +indefinite. According to this philosopher, the distinction that we are +to make of those primordial and secondary competitions, consists in +this, that the first are in such a shape and structure as cannot be +conceived to be formed by subsidence in water. + +M. de Saussure has carefully examined those same objects; and he seems +inclined to think that they must have been the operation of the ocean; +not in the common manner of depositing strata, but in some other way by +crystallization. The present theory supposes all those masses formed +originally in the ordinary manner, by the deposits or subsidence +of materials transported in the waters, and that those strata were +afterwards changed by operations proper to the mineral regions. + +But the subject of the present investigation goes farther, by inquiring +if, in the operations of the globe, a primary and secondary class of +bodies may be distinguished, so far as the one may have undergone the +operations of the globe, or the vicissitudes of sea and land, oftener +than the other, consequently must be anterior to the later productions +both in time and operation, although the original of all those bodies +be the same, and the operations of the earth, so far as we see in the +effects, always proceed upon the same principles. This is an extensive +view of nature to which few have turned their thoughts. But this is +a subject to which the observations described by this author have +evidently a reference. + +In his 113th letter, he has given us a view of one of those parts of the +earth that are proper to be examined in determining this question so +important in the genealogy of land, although no ways concerned in +altering the principles upon which nature in forming continents must +proceed. + +It is in describing the nature of the mountains about _Elbingerode_; and +he begins in ascending from Hefeld. + +"Cette partie exterieure de la chaine est _primordiale_: c'est du +_granit_ a _Hereld_ et au commencement de la route; puis quand on passe +dans d'autres vallees, on trouve les _schistes_ et la _roche grise_ dans +tout le pied des montagnes: mais des qu'on est arrive a une certain +hauteur, on voit de la _pierre a chaux_ par couches etendue sur ces +matieres; et c'est elle qui forme le sommet de ces memes montagnes; +tellement que la plaine elevee, qui conduit a _Elbingerode_, est +entierement de _pierre a chaux_, excepte dans sa partie la plus haute ou +cette pierre est recouverte des memes _gres_ et sables _vitrescibles_ +qui sont sur le schiste du Bruchberg et sur la _pierre a chaux_ dans la +_Hesse_ et le pays de Gottingue. + +"Les environs d'Elbingerode etant plus bas que ces parties recouvertes +de matieres vitrescibles, montrent la _pierre a chaux_ a nud; et l'on y +trouve de tres beaux marbres, dont les nuances jaunes, rouges et vertes +sont souvent tres vives, et embellies par les coupes des _corps marins_. + +"Cependant le schiste n'est pas enseveli partout sous ces depots de la +mer; on le retrouve en quelques endroits, et meme avec de _filons_. + +"Ainsi au milieu de ces matieres _calcaires_ qui forment le sol montueux +des environs _d'Elbingerode_, paroit encore le _schiste_ sur lequel +elles ont ete deposees: Et en montant a la partie la plus elevee de +ces memes environs, on trouve que la _pierre a chaux_ est recouverte +elle-meme d'une _pierre sableuse_ grise par couches, dans laquelle on +voit quantite de petits fragmens de _schiste_ poses de plat. C'est la +que se trouve une des mines de _fer_ dont le minerai va en partie a la +_Koningshutte_, mais en plus grande partie a la _Rothechutte_, qui n'est +qu'a une lieue de distance. On perce d'abord la couche sableuse; sous +elle se trouve de la _pierre a chaux_ grise; puis une couche de +_pierre a chaux ferrugineuse_, remplie de _corps marins_, et surtout +_d'entroques_: C'est cette _couche_ qui est ici le _minerai_; et elle +appartient a la formation de cette eminence comme toutes les autres +_couches_. Cette mine se nomme _bomshey_: elle n'est pas riche; mais +elle sert de _fondant_ aux matieres ferrugineuses tirees des filons des +montagnes primordiales en meme tems qu'elle leur ajoute son _fer_ dans +la fonte. A quelque distance de la on a perce un autre puits; qui a +transverse d'abord une sorte de pierre, que je ne saurois nommer, mais +qui ressemble fort a une _lave_ poreuse. Au dessous de cette couche on a +retrouve la _pierre a chaux_ ordinaire; puis la _couche ferrugineuse_ y +continue; mais elle differe un peu de ce qu'elle est dans l'autre mine, +une partie de sa substance etant convertie en _jaspe_. + +"Mais ce qui est digne de la plus grande attention dans cette contree, +est un filon peu distant nomme _Buchenberg_, qui appartient en partie au +Roi, et en partie a Mr. le Comte de _Wernigerode_. La montagne en cette +endroit montre une vallee artificielle de 70 a 80 pieds de profondeur, +de 20 a 30 de largeur dans le haut, et de 400 toises en etendue. C'est +le creusement qu'on a deja fait en suivant ce _filon_ de _fer_, que l'on +continue a exploiter de la meme maniere sur les terres de Mr. le Comte +de _Wernigerode_. La matiere propre de la montagne _est_ de _schiste_; +et la vallee qui se forme de nouveau a mesure qu'on enleve la _gangue_ +du _filon_, a surement deja existe dans la mer sous la forme d'une +_fente_, qui a ete remplie, et en particulier des ingrediens dont on +fait aujourd'hui le _fer_." + +Here is a supposition of our author that corresponds to nothing which +has yet been observed any where else, so far as I know. It is concerning +a mineral vein, one which does not appear to differ in any respect from +other mineral veins, except in being worked in that open manner which +has given our author an idea of its being a valley. He then supposes +that valley (or rather empty vein) to have been in this mountain when at +the bottom of the sea, and that this mineral vein had then been filled +with those materials which now are found in that space between the two +sides of the separated rock. This is a very different operation from +that of infiltration, which is commonly supposed to be the method of +filling mineral veins; but, we shall soon see the reason why our author +has here deserted the common hypothesis, and has adopted another to +serve the occasion, without appearing to have considered how perfectly +inconsistent those two suppositions are to each other. That mineral +veins have been filled with matter in a fluid state, is acknowledged by +every body who has either looked at a mineral vein in the earth, or in a +cabinet specimen; mineralists and geologists, in general, suppose this +to have been done by means of solutions and concretions, a supposition +by no means warranted by appearances, which, on the contrary, in general +demonstrate that the materials of those veins had been introduced in the +fluid state of fusion. But here is a new idea with regard to the filling +of those veins; and, I would now beg the reader's attention to the facts +which follow in this interesting description, and which have suggested +that idea to our author. + +"Quand cette matiere accidentelle est enlevee, on voit la coupe du +_schiste_ des deux cotes de la _fente_, faisant un _toit_ et un _mur_, +parce que la _fente_ n'est pas absolument verticale: des qu'il y a +un peu d'inclinaison, on distingue un _toit_ et un mur, comme j'ai +l'honneur de l'expliquer a V.M. On ne connoit point encore l'etendue de +ce filon, ni dans sa profondeur, ou l'on ne peut pas s'enfoncer beaucoup +de cette maniere, ni dans la longueur, selon laquelle on continue a +l'exploiter. + +"Voila donc un _filon_, a la rigueur de la definition que j'en ai donne +a V.M. c'est a dire, une _fente_ dans la montagne naturelle, _comblee_ +de _matiere_ etrangere. Mais ce qu'il y a d'extraordinaire ici, c'est +que cette _matiere_ vient de la _mer_: ce sont differentes _couches +aquiformes_, dont quelques unes sont remplies de _corps marins_. Il y +a des _couches_ d'une _terre martiale_ fort brune et sans liaison: +d'autres, au contraire toujours _martiales_, sont tres dures et +renferment de tres beau jaspe sanguin: d'autres enfin sont de vrai +_marbre_ gris veinees de rouge. C'est dans ce marbre que font les _corps +marins_, savoir des coquillages et des spongites; et il est lui-meme +martial comme tout le reste: les mineurs le nomment _Kubrimen_, et ne +l'employent que comme un _fondant_ pour d'autres _mineraux de fer_. + +"A ce _filon_, s'en joignent d'autres plus embarrassans. Ils viennent du +_toit_, qu'ils divisent par de larges _fentes_ comblees, aboutissantes +au _filon_ principale. Ils font de meme _calcaires_ et marins faits par +_couches_; mais ces _couches_ ont une si grande inclinaison, que je ne +puis les comprendre: il faut qu'il y ait eu d'etranges bouleversemens +dans ces endroits-la[27]. + +[Note 27: Here, no doubt, are appearances which it is impossible to +explain by the theory of infiltration; it is the filling of mineral +veins, and their branches or ramifications, with marble containing marks +of marine objects. But, if we shall suppose this marble to have been in +the fluid state of fusion, as well as the iron-ore and jasper, we may +easily conceive it introduced into the principal vein and its branches. +The description here given of those appearances is by no means such as +to enable us to judge particularly of this case, which surely merits the +most accurate investigation, and which, I doubt not, will give physical +demonstration of the fusion of those mineral substances. I know that +shells have been found within the body of veins in Germany; but, a +stratification of those materials in a vein was never heard of before, +so far as I know.] + +"Ces _fentes_ se sont faites, et ont ete remplies, dans la _mer_; +puisque les matieres qui les remplissent sont de la classe de ses depots +tres connoissables, et qu'il contiennent des _depouilles marines_. Mais +ce qui embarrasse alors c'est que les autres _filons_ ne soyent pas dans +le meme cas. N'est ce point la encore un indice, que ces _fentes_ out +ete d'abord et principalement remplies de matieres, poussees du fond par +la meme force qui secouoit les montagnes[28]. + +[Note 28: But what is this power by which matter is to be forced from +the bottom of the sea to the top of the mountains? For, unless we can +form some idea of that power which, as a cause, we ascribe to the +perceived effect, we either say nothing to the purpose, or we employ a +preternatural cause. It is not sufficient to imagine a power capable of +raising from the bottom of the sea the materials deposited in the abyss; +it is also necessary to find a power capable of softening bodies which +are hard, and of thus consolidating those masses which are formed of +loose or unconnected materials. Such a power, indeed, the present theory +assumes; and, so far as this shall be implied in the supposition of our +author, it will thus have received a certain conformation.] + +"Ce _filon_ n'est pas le seul dans le _Hartz_ qui donne des signes +_marins_. Il y en a un autre, qui meme se rapproche davantage de +la nature du commun des _filons_, et ou l'on trouve aussi des +_coquillages_. C'est celui de _Haus-Hartzbergerzug_, pres de +_Clausthal_, ou, dans les _Halles_ de quelques mines de plomb +abandonnees, et dans une forte _d'ardoise_, on trouve de petites +_moules_ ou _tellines_ striees, d'une espece particuliere que j'ai vue +dans des _ardoises secondaires d'Arotzen_ en _Waldek_ et de _Sombernon_ +en _Bourgogne_. Il y a donc certainement quelques _filons_ faits par les +depots de la _mer_ dans les _fentes_ de montagnes _primordiales_; comme +au contraire il y a des _filons_ metalliques sans indices _marins_, +dans des montagnes evidemment _secondaires_, telles que celles de +_Derbyshire_, ou les _filons_ de _plomb_ traversent des couches de +_pierre a chaux_." + +Here again our author seems to me to refute his own supposition, That a +chasm in the schistus rock may have existed at the bottom of the sea, +and been then filled from above with such materials as were transported +by the moving water to that place, is not impossible; but nobody, who +knows the nature of a common metallic vein, can ever suppose it to have +been filled in that manner. Our author then adds, "On ne fait reellement +que commencer dans ce genre d'observations, considerees quant a la +Cosmologie; ainsi il ne faut point desesperer que tout cela ne se +devoile un jour, et que nous n'acquerrions ainsi un peu plus de +connoissance sur ce qui se passoit dans la _mer ancienne_. + +"En revenant vers _Elbingerode_, nous retrouvames ces _schistes_, qui +paroissent au travers des _marbres:_ ils sont donc la continuation de la +masse _schisteuse_ a laquelle appartient le _filon_, dont je viens de +parler. Ce _filon_ a ete forme dans une _fente_, restee ouverte et vide: +les depots de la _mer_ l'ont comblee, en meme tems qu'ils formoient +les couches de _marbre_, qui sont a l'exterieur. En effet, ce _filon_ +contient des _couches marines ferrugineuses_, de la meme nature que +celles des collines calcaires voisines formees sur le schiste. + +"Nous partimes _d'Elbingerode_ dans l'apres midi pour nous rapprocher +de Clausthal. Notre chemin fut encore quelque tems sur des sommites +_calcaires_; et avant que d'en sortir, nous trouvames une autre mine +singuliere a _Arenfeld_. C'est encore un vrai _filon_; mais dans une +montagne de _pierre a chaux:_ C'est a-dire, que cette montagne a aussi +ete _fendue_, et que la _fente_ a ete remplie d'une _gangue_. La matiere +de ce _filon_ est encore _calcaire_ en plus grande partie; mais +cette _pierre a chaux_ distincte est _ferrugineuse_, et parsemee de +concretions de _jaspe_ comme celles _d'Elbingerode:_ on y trouve aussi +une matiere verdatre, qui, comme le _jaspe_, ne fait pas effervescence +avec l'eau forte." + +Here is a phenomenon which is altogether incompatible with the theory +that this author has given us for the explanation of those appearances. +He supposes empty crevices in the schistus mountains at the bottom of +the sea; these crevices he supposes filled by the deposits of the sea, +at the same time, and with the same materials with which the lime-stone +strata were formed above the schistus mountains; but we find one of +those same veins in these secondary calcareous strata. Now, tho' we +should be disposed to allow, that, in the primordial mountain, of which +we are supposed not to know the origin, there might have been empty +crevices which were afterwards filled with materials transported by the +sea, this cannot be admitted as taking place in the loose or incoherent +materials deposited above the schistus. Consequently, this theory of our +author, which is evidently erroneous with regard to the veins in the +lime-stone, must, in the other case, be at least examined with a jealous +eye. + +"Le haut de cette partie des montagnes _calcaires_ etoit encore +recouvert de _sable_ et de gres _vitrescibles_: et continuant a marcher, +sans aucune inflexion sensible, nous nous trouvames subitement sur les +_schistes_; d'ou nous montames plus rapidement. Puis traversant quelques +petites vallees nous arrivames sur les montagnes qui appartiennent au +prolongement du _Brocken_ ou _Blocksberg_. La matiere dominante est +alors le _granit_; mais il est tout en blocs le long de cette route, et +ces blocs se trouvent a une telle distance de tout sommite intacte de +cette pierre, qui est aise de juger non seulement qu'ils ne sont pas +dans leur place originaire, mais encore qu'il ne sont arrives la par +aucune des causes naturelles qui agissent dans les montagnes; savoir, +la pesanteur, la pente, et le cours des eaux. Ce sont donc de violentes +explosions qui ont disperse ces blocs; et alors ils deviennent un +nouveau trait cosmologique de quelque importance: car rien ne se meut, +ni ne paroit s'etre mu depuis bien des siecles, dans ces lieux qui +montrent tant de desordre: un tapis de verdure couvre tout, en +conservant les contours baroques du sol. Le betail ne sauroit paturer +dans de telles prairies; mais l'industrieux montagnard fait y +faucher[29]. + +[Note 29: M. de Saussure endeavours to explain those appearances of +transported blocks of granite by another cause; this is a certain +_debacle_ of the waters of the earth, which I do not understand. M. de +Luc again attempts to explain it by violent explosions; I suppose he +means those of a volcano. But he has not given us the evidence upon +which such an opinion may be founded, farther than by saying that those +blocks could not have come there by the natural operations of the +surface. By this must be meant, that, from the nearest summit of +granite, there is not, at present, any natural means by which these +blocks might be transported to that place. But it is not with the +present state of things that we are concerned, in explaining the +operations of a distant period. If the natural operations of the surface +change the shape of things, as is clearly proved by every natural +appearance, Why form an argument against a former transaction, upon the +circumstances of the present state of things? Our author does not +seem to perceive, that, from this mode of reasoning, there is is an +insuperable objection to his violent explosions having been employed in +producing those effects. For, had there been such a cause, the evidence +of this must have remained; if the surface of the earth does not undergo +great changes: If, again, this surface be in time much changed, How can +we judge from the present shape, what might have been the former posture +of things? + +This author, indeed, does not allow much time for the natural operations +of the globe to change its surface; but, if things be not greatly +removed from the state in which the violent operations of the globe had +placed them, Why does he not point out to us the source of this great +disorder which he there perceives? From what explosion will be explained +the blocks of granite which are found upon the Jura, and which must have +come from the mass of _Mont Blanc_? If these dispersed blocks of +stone are to be explained by explosion, there must: have been similar +explosions in other countries where there is not the smallest appearance +of volcanic eruptions; for, around all our granite mountains, and I +believe all others, there are found many blocks of granite, traveled at +a great distance, and in all directions.] + +"_Oberbruck_, ou nous avions ete la precedente fois, se trouva sur notre +route, et nous y passames aussi la nuit, dans l'esperance de pouvoir +monter le lendemain sur le _Brocken_; mais il fut encore enveloppe de +nuages; ainsi nous continuames a marcher vers _Clausthal_, passant de +nouveau par le _Bruchberg_, ou le _sable_ et ses gres recouvrent le +_schiste_; puis arrivant a une autre sommite, nous y trouvames la meme +pierre _sableuse_ par couches, melee de parcelles de _schiste_, que nous +avions vue sur les montagnes _calcaires d'Elbingerode_. Il est donc +toujours plus certain que le sol primordial de toutes ces montagnes +existoit sous les eaux de l'ancienne mer; puisqu'il est recouvert de +diverses fortes de depots, connus pour appartenir a la _mer_; et que les +_fentes_ des _filons_ existoient dans cette _mer ancienne_; puisqu'elle +en a rempli elle-meme quelques unes, et qu'elle a recouvert de ses +depots quelques autres _filons_ tout formes. Quant a celles des matieres +de ces _filons_, qui ne paroissent pas etre _marines_ (et c'est de +beaucoup la plus grande quantite), j'ai toujours plus de penchant d'en +attribuer une partie a l'operation des _feux souterreins_, a mesure que +je vois diminuer la probabilite de les assigner entierement a _l'eau_. +Mais quoi-qu'il en soit, ces gangues ne font pas de meme date que les +montagnes[30]. + +[Note 30: I most willingly admit the justness of our author's view, if +he thus perceives the operation of fire in the solids of our earth; but +it is not for the reasons he has given us for discovering it here more +than in other places; for there is not a mineral vein, (so far at least +as I have seen), in which the appearances may be explained by any thing +else besides the operation of fire or fusion. It is not easy to conceive +in what manner our author had conceived the opinions which he has +displayed in these letters. He had no opinion of this kind, or rather he +was persuaded that subterraneous fire had no hand in the formation of +this earth before he came to this place of the Hartz; here he finds +certain appearances, by which he is confirmed in his former opinion, +that water had operated in forming mineral veins; and then he forms the +idea that subterraneous fire may have operated also. But, before the +discovery of the chasms in the schistus mountains having been filled +with the stratified materials of the sea, How had he supposed veins to +be filled? If this philosopher had before no opinion of subterraneous +fire, as instrumental in that operation, How comes he now to change that +former opinion? For, unless it be the extraordinary manner of filling +these open crevices in the mountains by matter deposited immediately +from the sea, there is certainly no other appearance in this mineral +country of the Hartz, that may not be found in any other, only perhaps +upon a smaller scale.] + +"Le lendemain de notre arrivee a _Clausthal_, qui etoit le 13e, nous +allames visiter d'autres mines de _fer_ en montagnes secondaires, +situees au cote oppose du Hartz. Elles sont aupres de _Grund_ l'une +des _villes de mines_, et pres du lieu ou sortira la nouvelle _galerie +d'ecoulement_ a laquelle on travaille, etc. + +"Arrives a _Grund_ les officiers mineurs vinrent, comme a l'ordinaire, +accompagner Mons. de _Reden_ aux _mines_ de leur departement. Celles-ci, +sans etre plus extraordinaires que celles qui nous avions vues a +_Elbingerod_, ou sans aider mieux jusqu'ici a expliquer ce qu'elles ont +toutes d'extraordinaire, nous donnent au moins des indices probables +de grands accidens. Ces montagnes de _Grund_ sont encore de l'espece +remarquable, dont la base est de _schiste_, et le haut de _pierre a +chaux_. Les mines qu'on y exploit sont de _fer_, et se trouvent dans +cette matiere _calcaire_; mais elles y sont sous des apparences +tout-a-fait etranges. La montagne ou nous les vimes principalement le +nomme _Iberg_. On y poursuit des masses de _pierre a fer_, de l'ensemble +desquelles les mineurs ne peuvent encore se rendre compte d'une maniere +claire. Ils ont trouve dans cette montagne des _ca__vernes_, qui +ressemblent a l'encaissement de _sillons_ deja exploites, ou non formes; +c'est-a-dire, que ce sont des _fentes_ presque verticales, et vides, Le +_minerai_ qu'ils poursuivent est en _Rognons_; c'est a dire, en grandes +masses sans continuite decidee. Cependant ces masses semblent se +succeder dans la montagne suivant une certaine direction; tellement que +les mineurs savent deja les chercher, par des indices d'habitude. +La substance de cette _pierre a fer_ particuliere renferme des +crystallizations de diverses especes. Il y a des _druses de quartz_, ou +de petits cristaux de quartz qui tapissent des cavites; il y a aussi du +_spath_ commun, et de celui qu'on nomme pesant; on y trouve enfin une +forte de crystallization nommee _Eisenman_ (_homme de fer_) par les +mineurs; se sont des amas de cristaux noir-atres, qui ressemblent a +des groupes de grandes lentilles plattes, et ces cristaux sont +_ferrugineux_. + +"Entre les signes de bouleversement que renferme ce lieu, est un +rocher nomme _Gebichensten_, qui est en _pierre a chaux_, ce que +_l'Ebrenbreitstein_ de _Coblentz_ est en pierre sableuse: c'est-a-dire, +que ses _couches_, remplies de _corps marins_, sont presque verticales; +ceux de ces corps qu'on y trouve en plus grande quantite, sont des +_madrepores_. Ce rocher s'eleve comme un grand obelisque, au-dessus des +_cavernes_, dont j'ai parle; montrant par le cote ses _couches_, qui se +trouvent, comme je l'ai dit, dans une situation presque verticale. Sa +base est deja bien minee, tant par les _cavernes_, que par la _pierre +a fer_ qu'on en tire; et je ne me hasardai dessus, que parce que je me +dis, qu'il y a des millions contre un a parier, que ce n'est pas le +moment ou il s'enfoncerait. Mais je n'en dirois pas autant, s'il +s'agissoit de m'y loger a demeure. + +"Quoique tout ce lieu la soit fort remarquable, il se pourrait que ce +ne fut qu'un phenomene particulier. Les _cavernes_ peuvent devoir leur +origine a la meme cause que celle de Schartzfeld; et le derangement des +rochers superieurs a des enfoncemens occasionnes par ces _cavernes_. +Rien n'est si difficile que de retracer aujourd'hui ces fortes +d'accidens a cause des changemens que le tems y a operes. S'ils sont +arrives sous les eaux de la _mer_, on concoit aisement les alterations +qui ont du succeder; et si c'est depuis que nos continens sont a sec, +les eaux encore, tant interieures qu'exterieures, et la vegetation, en +ont beaucoup change l'aspect." + +This author has a theory by which he explains to himself the former +residence of the sea, above the summits of our mountains; this, +however, is not the theory by which we are now endeavouring to explain +appearances; we must therefore be allowed to reason from our own +principles, in considering the facts here set forth by our author. + +Nothing, I think, is more evident, than that in this mineral country of +the Hartz, we may find the clearest marks of fracture, elevation, and +dislocation of the strata, and of the introduction of foreign matter +among those separated bodies. All those appearances, our author would +have to be nothing but some particular accident, which is not to enter +into the physiology of the earth. I wish again to generalise these +facts, by finding them universal in relation to the globe, and +necessarily to be found in all the consolidated parts of our land. + +It was not to refute our author's reasoning that I have here introduced +so much of his observations, but to give an extensive view of the +mineral structure of this interesting country. This therefore being +done, we now proceed to what is more peculiarly our business in this +place, or the immediate subject of investigation, viz. the distinction +of primary and secondary strata. + +"Dans le voisinage de cette montagne, il y a une autre fort +interessante, que je vis le jour suivant. Quoiqu'en traitant des +volcans, j'aie demontre que la formation des montagnes, par soulevement, +etoit sans exemple dans les faits, et sans fondement dans la theorie, je +ne laisseroi pas de m'arreter au phenomene que presente cette montagne; +parce qu'il prouvera directement que les _couches calcaires_ au moins, +ont ete formees _a la hauteur ou elles sont_; c'est-a-dire qu'elles +n'ont pas ete soulevees. + +"Voulant prendre l'occasion de mon retour a _Hanovre_, pour traverser +les avant-corps du _Hartz_, dans quelque nouvelle direction; je resolus +de faire ce voyage a cheval, et de prendre ma route droite vers +_Hanovre_, au-travers des collines; ce qui me conduisit encore a _Grund_ +puis a _Muenchehof Brunshausen, Engelade, Winsenburg_ et _Alfeld_, ou +enfin, traversant la _Leine_ j'entrai dans la grande route. + +"Je quittai donc _Clausthal_ (et avec bien du regret) le 14 au matin; +et revenant d'abord a _Grund_, je le laissai sur ma droite, ainsi +que _l'Iberg_; et plus loin, du meme cote, une autre montagne nommee +_Winterberg_ dont la base est _schiste_, et le sommet plus haut que +Clausthal, entierement compose de _couches calcaires_. De _Grund_ je +montai vers une montagne nommee _Ost Kamp_; et je commencai la a donner +une attention particuliere au sol. Le long de mon chemin, je ne trouvai +longtemps que des schistes, qui montroient leurs points en haut, comme a +l'ordinaire, et avec tous leurs tortillemens de feuillets. Mais arrive +au haut de la montagne, j'y vis des carrieres de _pierre a chaux_, ou +les couches absolument regulieres, et qui ont peu d'epaisseur sur le +_schiste_ suivent parfaitement les contours du _sommet_. Ces lits de +_pierre a chaux_ n'ont certainement pas ete souleves du fond de la _mer_ +sur le dos des schistes; lors meme qu'a cause de la grande inclinaison +des feuillets de ceux-ci on voudroit le attribuer a quelque revolution +telle que le _soulevement_; (ce que je n'admettrois point). Car si ces +lits _calcaires_, ayant ete faits au fond de la _mer_, avoyent ete +souleves avec les schistes, ne feroient-ils pas brises et bouleverses +comme eux? Il est donc evident, que quoiqu'il soi arrive au schiste qui +les porte, ces lits, et tous les autres de meme genre qui sont au haut +de ces montagnes, ont ete deposees au niveau ou ils sont; et que +par consequent la _mer_ les surpassoit alors. Ainsi le systeme de +soulevement perd son but, s'il tend a expliquer pourquoi nous avons des +_couches_, formees par la mer, qui se trouvent maintenant si fort au +dessus de son niveau. Il est evident que ces _couches_ n'ont pas ete +soulevees; mais que la _mer_ s'est _abaissee_. Or c'est la le grand +point cosmologique a expliquer: tous les autres, qui tiennent a la +structure de certaines montagnes inintelligibles, n'appartiendront qu'a +_l'histoire naturelle_, tant qu'ils ne se lieront pas avec celui-la." + +Here are two things to be considered; the interesting facts described +by our author, and the inference that he would have us draw from those +facts. It would appear from the facts, that the body of schistus below, +and that of lime-stone above, had not undergone the same disordering +operations, or by no means in the same degree. But our author has formed +another conclusion; he says, that these lime-stone strata must have been +formed precisely in the place and order in which they lie at present; +and the reason for this is, because these strata appeared to him to +follow perfectly the contour of the summit of this mountain. Now, had +there been in the top of this mountain a deep hollow encompassed about +with the schistus rock; and had this cavity been now found filled with +horizontal strata, there might have been some shadow of reason for +supposing those strata to have been deposited upon the top of the +mountain. But to suppose, _first_, that shells and corals should be +deposited upon the convex summit of a mountain which was then covered by +the sea; _secondly_, that these moveable materials should remain upon +the summit, while the sea had changed its place; and, _lastly_, that +those shells and corals left by the sea upon the top of a mountain +should become strata of solid limestone, and have also metallic veins +in it, certainly holds of no principle of natural philosophy that I am +acquainted with. If, therefore, such an appearance as this were to be +employed either in illustration or confirmation of a theory, it +would itself require to be explained; but this is a task that this +cosmologists does not seem willing to undertake. + +He has formed a hypothesis for explaining the general appearance of that +which was once the bottom of the sea being now found forming the summits +of our mountains; but surely this philosopher will acknowledge, that +those natural appearances, in any particular place, will be the same, +whether we suppose the bottom of the sea to have been raised, as in the +present theory, or the surface of the sea to have sunk according to his +hypothesis. For, it is equally easy to suppose a portion of the earth +to have been raised all this height, as to suppose all the rest of the +surface of the globe to have sunk an equal space, while a small portion +of the bottom of the sea, remaining here and there fixed in its place, +became the highest portion of the globe. Consequently, whatever evidence +this philosopher shall find in support of his theory of the present +earth, (a subject which it is not our purpose to examine) it cannot be +allowed that he has here brought any argument capable of disproving the +elevation of the bottom of the sea; a supposition which other theories +may require. + +I would now observe, in relation to the present theory, that so far +as this author has reasoned justly from natural appearances, his +conclusions will be found to confirm the present supposition, that there +is to be perceived the distinction of primordial, and that of secondary, +in the masses of this earth, without altering the general theory either +with respect to the original formation of those masses, or to their +posterior production. + +Here one of two things must be allowed; either that those strata +of schistus had been broken and distorted under a mass of other +superincumbent strata; or that those superincumbent strata had been +deposited upon the broken and distorted strata at the bottom of the sea. +Our author, who has examined the subject, inclines to think, that this +last has been the case. If, therefore, strata had been deposited upon +broken and bare rocks of schistus, it is probable that these had been +sunk in the sea after having been exposed to the atmosphere, and served +the purpose of land upon the globe.[31] + +[Note 31: This is also supported by another very interesting observation +contained in this letter. M. de Luc observes, that in this country the +schistus is generally covered by strata of lime-stone, and that these +lime-stone strata are again covered with those of sand-stone, in which +are found a great many fragments of schistus lying flat. Therefore, +while those sand-stone strata were collecting at the bottom of the sea, +there had been rocks of schistus in some other place, from whence those +fragments bad been detached.] + +An example of the same kind also occurs in the _Discours sur l'Histoire +Naturelle de la Suisse_; and this author of the _Tableaux de la Suisse_ +has given a very distinct description of that appearance, which is +perhaps the more to be valued as a piece of natural history, as this +intelligent author does not pretend to any geological theory, but simply +narrates what he has seen, with such pertinent observations on +the subject as naturally must occur to a thinking person on the +spot.--(Discours, etc. page 228. Entree au pays de Grisons). + +"Du village d'Elen on continue a monter le reste du petit vallon pendant +une lieue et demie parmi les memes especes de pierres qu'on vient de +decrire; en passant au travers de bois et de forets de sapins et de +quelques paturages dont ce haut est couvert, on parvient au pied du +Bundnerberg, montagne des grisons, qui forme la tete du vallon. On +laisse a droite un fond ou espece d'entonnoir, entoure de tres-hautes +montagnes inaccessibles, pour s'enfourrer a gauche entre des rochers qui +font fort resserres, ou coule un torrent. Ce lieu seroit horreur si +on ne se trouvoit accoutume, par degres, a voir de ces positions +effrayantes: tout y est aride, il n'y a plus d'arbres ni de vegetaux ce +sont des rochers entasses les un sur les autres; ce lieu paroit d'autant +plus affreux que le passage a ete subit, et qu'en sortant de bois et des +forets, on se trouve tout-a-coup parmi ces rochers qui s'elevent comme +des murailles, et dont on ne voit pas la cime; cette gorge ou cette +entree qui se nomme Jetz, est la communication du Canton du Glaris aux +Gritons; on a dit precedemment qu'il y en avoit une plus aisee par +le Gros-Thal ou le grand vallon. Ce passage est tres-curieux pour la +Lithogeognosie, il est rare de trouver autant de phenomenes interessans +rassembles, et des substances aussi variees par rapport a leurs +positions; c'est le local qui merite le plus d'etre examine en Suisse, +et la plus difficile que nous ayons parcouru. On se souviendra que nous +avons continuellement monte depuis Glaris, et que nous nous trouvons au +pied de ces montagnes ou de ces pics etonnans qui dominent les hautes +Alpes; on trouve ici la facilite peu commune de pouvoir examiner, et +voir le pied ou les fondemens de ces colosses qui couronnent le globe, +parce qu'ils sont ordinairement entoures de leurs debris et de leurs +eboulemens qui en cachent le pied. Ici c'est une roche de schiste +bleuatre, dure et compact, traversee de filons de quartz blanc, et +quelquefois jaunatre, dans laquelle on a taille un sentier pour pouvoir +en franchir le pied. Cette roche s'eleve a une hauteur prodigieuse, +est presque verticale, et ces couches sont a quatre-vingt degres +d'inclinaison. L'imagination est effrayee de voir que de pareilles +masses ayent pu etre ebranlees et deplacees au point d'avoir fait +presque un quart de conversion. Apres avoir monte et suivi cette roche +parmi les pierres et les decombres, une heure et demie, on trouve +cette roche de schiste surmontee d'autres rochers fort hauts qui sont +calcaires, et dont les lits sont fort horizontaux. Les schistes, +qui sont directement sous les roches calcaires, conservent la meme +inclinaison qu'elles ont a leur pied." + +Here is an observation which certainly agrees with that given by M. de +Luc, and would seem to confirm this conclusion, that strata had been +deposited upon those _schisti_ after they had been changed from their +natural or horizontal position, and become vertical; at the same time, +this conclusion is not of necessary consequence, without examining +concomitant appearances, and finding particular marks by which this +operation might be traced; for the simply finding horizontal strata, +placed above vertical or much inclined schiste, is not sufficient, of +itself, to constitute that fact, while it is acknowledged that every +species of fracture, dislocation, and contortion, is to be found among +the displaced strata of the globe. + +Since writing this chapter, I am enabled to speak more decisively upon +that point, having acquired more light upon the subject, as will appear +in the next chapter. + + + +CHAP. VI. + +The Theory of interchanging Sea and Land illustrated by an +Investigation of the Primary and Secondary Strata. + + +SECT. I.--A distinct View of the Primary and Secondary Strata. + +Having given a view of what seems to be the primary and secondary +strata, from the observations of authors, and having given what was +my opinion when I first wrote that chapter, I am now to treat of this +subject from observations of my own, which I made since forming that +opinion. + +From Portpatrick, on the west coast, to St Abb's Head, on the east, +there is a tract of schistus mountains, in which the strata are +generally much inclined, or approaching to the vertical situation; and +it is in these inclined strata that geologists allege that there is not +to be found any vestige of organised body. This opinion, however, I have +now proved to be erroneous. + +There cannot be any doubt with regard to the original formation of those +stratified bodies, as having been formed of the materials that are +natural to this earth, viz. the detritus of former bodies; and as having +been deposited in water, like the horizontal strata: For the substances +and bodies of which they are visibly composed are no other than those +which form the most regular horizontal strata, and which are continually +traveling, or transported at the bottom of the sea, such as gravel, and +sand, argillaceous and micaceous bodies. + +On each side of this ridge of mountains, which towards the east end is +but narrow, there is a lower country composed of strata in general more +horizontal; and among which strata, besides coal, there are also found +the relics of organised bodies. + +Abstracting at present from any consideration of organised bodies among +the materials of those strata, it may be affirmed, that the materials +which form the strata in the mountains and in the low country, are +similar, or of the same nature; that they have, in both places, been +consolidated by the same means, viz. heat and fusion; and that the same +or similar accidents have happened to them, such as change from their +original position, and mineral veins traversing them in various shapes. +Yet still there is a distinctive character for those two bodies, the +alpine and the horizontal strata; for, while the horizontal position +appears natural to the one, and the changes from that particular state +to be only an accident, the vertical position appears to be more natural +to the other, which is seldom found horizontal. + +Therefore, altho' it is unquestionable that the strata in the alpine and +low countries had the same or a similar original, yet, as the vertical +position, which is the greatest possible change in that respect, is more +natural to the alpine strata, or only necessary in the natural order of +those bodies, we are to consider this great disorder or change from the +natural state of their original formation, as the proper character of +those alpine strata. But then it is also necessary to include in this +character a general hardness and solidity in those vertical strata, +otherwise they would not have been properly alpine, or have resisted the +wearing and washing powers of the globe, so as to have remained higher +than the others; for, the vertical position, or great inclination of +those strata, should rather have disposed them the more to dissolution +and decay. Let us now see how far we shall be justified in that general +conclusion, by the examination of those bodies. + +The fact is certain, that those alpine bodies are much harder, or less +subject to dissolution and decay, than the horizontal strata. But this +must be taken in the general, and will by no means apply to particular +cases which might be compared. Nothing, for example, more solid than the +lime-stones, or marbles, and iron-stones; nothing more hard or solid +than the chirt or flint; and all these are found among the horizontal +strata. But, while some strata among those horizontal beds are +thus perfectly solid, others are found with so slight degrees of +consolidation, that we should not be able to ascribe it to the proper +cause, without that gradation of the effect, which leads us to impute +the slightest degree of consolidation to the same operations that have +produced the complete solidity. While, therefore, the most perfect +solidity is found in certain strata, or occasionally among the +horizontal bodies, this forms no part of their character in general, or +cannot be considered as a distinctive mark, as it truly is with +regard to the alpine strata. These last have a general character of +consolidation and indissolubility, which is in a manner universal. We +are, therefore, now to inquire into the cause of this distinction, and +to form some hypothesis that may be tried by the actual state of things, +in being compared with natural appearances. + +As the general cause of consolidation among mineral bodies, formed +originally of loose materials, has been found to consist in certain +degrees of fusion or cementation of those materials by means of heat; +and as, in the examination of the horizontal strata we actually +find very different degrees of consolidation in the several strata, +independent of their positions in relation to height or depth, we have +reason to believe that the heat, or consolidating operation, has not +been equally employed in relation to them all. + +We are not now inquiring how an inferior stratum should have been heated +in a lesser degree, or not consolidated, while a superior stratum had +been consolidated in the most perfect manner; we are to reason upon a +fact, which is, that the horizontal strata in general appear not to have +been equally or universally consolidated; and this we must attribute to +an insufficient exertion of the consolidating cause. But, so far as the +erecting cause is considered as the same with that by which the elevated +bodies were consolidated, and so far as the vertical situation is a +proof of the great exertion of that subterraneous power, the strata +which are most erected, should in general be found most consolidated. + +Nothing more certain than that there have been several repeated +operations of the mineralising power exerted upon the strata +in particular places; and all those mineral operations tend to +consolidation: Therefore, the more the operations have been repeated in +any place, the more we should find the strata consolidated, or changed +from their natural state. Vertical strata have every appearance from +whence we should be led to conclude, that much of the mineral power +had been exerted upon them, in changing their original constitution or +appearance. But the question now to be considered is this, How far +it may appear that these masses of matter, which now seem to be so +different from the ordinary strata of the globe, had been twice +subjected to the mineral operations, in having been first consolidated +and erected into the place of land, and afterwards sunk below the +bottom of the sea, in order a second time to undergo the process of +subterraneous heat, and again be elevated into the place where they now +are found. + +It must be evident, here is a question that may not be easy to decide. +It is not to the degree of any change to which bodies may be subject, +that we are to appeal, in order to clear up the point in question, +but to a regular course of operations, which must appear to have been +successively transacted, and by which the different circumstances or +situations of those masses are to be discovered in their present state. +Now, though it does not concern the present theory that this question be +decided, as it is nothing but a repetition of the same operations that +we look for; nevertheless, it would be an interesting fact in the +natural history of this earth; and it would add great lustre to a theory +by which so great, so many operations were to be explained. I am far +from being sanguine in my expectations of giving all the satisfaction +in relation to this subject that I could wish; but it will be proper to +state what I have lately learned with regard to so curious a question, +that others, who shall have the opportunity, may be led to inquire, and +that thus the natural history of the earth may be enlarged, by a proper +investigation of its mineral operations. + +With this view I have often considered our schistus mountains, both in +the north and south; but I never found any satisfactory appearance from +whence conclusions could be formed, whether for the question or against +it. The places I examined were those between the alpine countries and +the horizontal strata; here, indeed, I have frequently found a confused +mass, formed of the fragments of those alpine strata mixed with the +materials of the horizontal bodies; but not having seen the proper shape +and connection of those several deposits, I always suspended my judgment +with regard to the particular operations which might have been employed +in producing those appearances. + +I had long looked for the immediate junction of the secondary or low +country strata with the alpine schistus, without finding it; the first +place in which I observed it was at the north end of the island of +Arran, at the mouth of Loch Ranza; it was upon the shore, where the +inclined strata appeared bare, being; washed by the sea. It was but a +very small part that I could see; but what appeared was most distinct. +Here the schistus and the sandstone strata both rise inclined at an +angle of about 45 deg.; but these primary and secondary strata were +inclined in almost opposite directions; and thus they met together like +the two sides of a _lambda_, or the rigging of a house, being a little +in disorder at the angle of their junction. From this situation of those +two different masses of strata, it is evidently impossible that either +of them could have been formed originally in that position; therefore, I +could not here learn in what state the schistus strata had been in when +those of the sand-stone, &c, had been superinduced. + +Such was the state of my mind, in relation to that subject:, when at +Jedburgh upon a visit to a friend, after I had returned from Arran, and +wrote the history of that journey; I there considered myself as among +the horizontal strata which had first appeared after passing the Tweed, +and before arriving at the Tiviot. The strata there, as in Berwickshire, +which is their continuation to the east, are remarkably horizontal for +Scotland; and they consist of alternated beds of sand-stone and marl, or +argillaceous and micaceous strata. These horizontal strata are traversed +in places with small veins of whin-stone, as well as greater masses +forming rocks and hills of that material; but, except it be these, (of +which there are some curious examples), I thought there could be nothing +more of an interesting nature to observe. Chance, however, discovered to +me what I could not have expected or foreseen. + +The river Tweed, below Melrose, discovers in its bed the vertical strata +of the schistus mountains, and though here these indurated bodies are +not veined with quartz as in many places of the mountains, I did not +hesitate to consider them as the same species, that is to say, the marly +materials indurated and consolidated in those operations by which they +had been so much changed in their place and natural position. Afterwards +in travelling south, and seeing the horizontal softer strata, I concluded +that I had got out of the alpine country, and supposed that no more of +the vertical strata were to be observed. + +The river Tiviot has made a wide valley as might have been expected, in +running over thole horizontal strata of marly or decaying substances; +and the banks of this river declining gradually are covered with gravel +and soil, and show little of the solid strata of the country. This, +however, is not the case with the Jed, which is to the southward of the +Tiviot; that river, in many places, runs upon the horizontal strata, and +undermines steep banks, which falling shows high and beautiful sections +of the regular horizontal strata. The little rivulets also which fall +into the Jed have hollowed out deep gullies in the land, and show the +uniformity of the horizontal strata. + +In this manner I was disposed to look for nothing more than what I had +seen among those mineral bodies, when one day, walking in the beautiful +valley above the town of Jedburgh, I was surprised with the appearance +of vertical strata in the bed of the river, where I was certain that +the banks were composed of horizontal strata. I was soon satisfied with +regard to this phenomenon, and rejoiced at my good fortune in stumbling +upon an object so interesting to the natural history of the earth, and +which I had been long looking for in vain. + +Here the vertical strata, similar to those that are in the bed of +the Tweed, appear; and above those vertical strata, are placed the +horizontal beds, which extend along the whole country. + +The question which we would wish to have solved is this; if the vertical +strata had been broken and erected under the superincumbent horizontal +strata; or if, after the vertical strata had been broken and erected, +the horizontal strata had been deposited upon the vertical strata, +then forming the bottom of the sea. That strata, which are regular and +horizontal in one place, should be found bended, broken, or disordered +at another, is not uncommon; it is always found more or less in all our +horizontal strata. Now, to what length this disordering operation might +have been carried, among strata under others, without disturbing the +order and continuity of those above, may perhaps be difficult to +determine; but here, in this present case, is the greatest disturbance +of the under strata, and a very great regularity among those above. Here +at least is the most difficult case of this kind to conceive, if we are +to suppose that the upper strata had been deposited before those below +had been broken and erected. + +Let us now suppose that the under strata had been disordered at the +bottom of the sea, before the superincumbent bodies were deposited; it +is not to be well conceived, that the vertical strata should in that +case appear to be cut off abruptly, and present their regular edges +immediately under the uniformly deposited substances above. But, in the +case now under consideration, there appears the most uniform section +of the vertical strata, their ends go up regularly to the horizontal +deposited bodies. Now, in whatever state the vertical strata had been in +at the time of this event, we can hardly suppose that they could have +been so perfectly cut off, without any relict being left to trace that +operation. It is much more probable to suppose, that the sea had washed +away the relics of the broken and disordered strata, before those that +are now superincumbent had been begun to be deposited. But we cannot +suppose two such contrary operations in the same place, as that of +carrying away the relics of those broken strata, and the depositing of +sand and subtile earth in such a regular order. We are therefore led +to conclude, that the bottom of the sea, or surface of those erected +strata, had been in very different situations at those two periods, when +the relics of the disordered strata had been carried away, and when the +new materials had been deposited. + +If this shall be admitted as a just view of the subject, it will be fair +to suppose, that the disordered strata had been raised more or less +above the surface of the ocean; that, by the effects of either rivers, +winds, or tides, the surface of the vertical strata had been washed +bare; and that this surface had been afterwards sunk below the influence +of those destructive operations, and thus placed in a situation proper +for the opposite effect, the accumulation of matter prepared and put in +motion by the destroying causes. + +I will not pretend to say that this has all the evidence that should be +required, in order to constitute a physical truth, or principle from +whence we were to reason farther in our theory; but, as a simple fact, +there is more probability for the thing having happened in that manner +than in any other; and perhaps this is all that may be attained, though +not all that were to be wished on the occasion. Let us now see how +far any confirmation may be obtained from the examination of all the +attending circumstances in those operations. + +I have already mentioned, that I had long observed great masses of +_debris_, or an extremely coarse species of pudding-stone, situated on +the south as well as north sides of those schistus mountains, where the +alpine strata terminate in our view, and where I had been looking for +the connection of those with the softer strata of the low country. +It has surely been such appearances as these which have often led +naturalists to see the formation of secondary and tertiary strata formed +by the simple congestion of _debris_ from the mountains, and to suppose +those masses consolidated by the operation of that very element by which +they had been torn off from one place and deposited in another. I never +before had data from whence to reason with regard to the natural history +of those masses of gravel and sand which always appeared to me in an +irregular shape, and not attended with such circumstances as might give +light into their natural history; but now I have found what I think +sufficient to explain those obscure appearances, and which at the same +time will in some respect illustrate or confirm the conjecture which +has now been formed with regard to the operations of the globe in those +regions. + +In describing the vertical and horizontal strata of the Jed, no mention +has been made of a certain pudding-stone, which is interposed between +the two, lying immediately upon the one and under the other. This +puddingstone corresponds entirely to that which I had found along +the skirt of the schistus mountains upon the south side, in different +places, almost from one end to the other. It is a confused mass of +stones, gravel, and sand, with red marly earth; these are consolidated +or cemented in a considerable degree, and thus form a stratum extremely +unlike any thing which is to be found either above or below. + +When we examine the stones and gravel of which it is composed, these +appear to have belonged to the vertical strata or schistus mountains. +They are in general the hard and solid parts of those indurated +strata, worn and rounded by attrition; particularly sand or marl-stone +consolidated and veined with quartz, and many fragments of quartz, all +rounded by attrition. In this pudding-stone of the Jed, I find also +rounded lumps of porphyry, but have not perceived any of granite.[32] +This however is not the case in the pudding-stone of the schistus +mountains, for, where there is granite in the neighbourhood, there is +also granite in the pudding-stone. + +[Note 32: A view of this object is seen in plate 3d. It is from a +drawing taken by Mr Clerk of Eldin.] + +From this it will appear, that the schistus mountains or the vertical +strata of indurated bodies had been formed, and had been wasted and worn +in the natural operations of the globe, before the horizontal strata +were begun to be deposited in those places; the gravel formed of those +indurated broken bodies worn round by attrition evince that fact. But +it also appears that the mineral operations of the globe, melting and +consolidating bodies, had been exerted upon those deposited strata above +the vertical bodies. + +This appears evidently from the examination of our pudding-stone. The +vertical strata under it are much broken and injected with ferruginous +spar; and this same spar has greatly penetrated the pudding-stone above, +in which are found the various mineral appearances of that spar and iron +ore. + +But those injecting operations reach no farther up among the marl strata +in this place; and then would appear to have been confined to the +pudding-stone. But in another place, about half a mile farther up the +river, where a very deep section of the strata is discovered, there +are two injections from below; the one is a thin vein of whin-stone or +basaltes, full of round particles of steatites impregnated with copper; +it is but a few inches wide, and proceeds in a kind of zigzag. The other +appears to have been calcareous spar, but the greatest part of it is now +dissolved out. The strata here descend to the bottom of the river, which +is above the place of the pudding-stone and vertical strata. Neither are +these last discoverable below the town of Jedburgh, at least so far as +I have seen; and the line of division, or plane of junction of the +vertical and horizontal strata, appears to decline more than the bed of +the river. + +But it may be asked, how the horizontal strata above, among which are +many very strong beds, have been consolidated. The answer to this +question is plain. Those strata have been indurated or consolidated +in no other manner than the general strata of the earth; these being +actually the common strata of the globe; while the vertical or schistus +strata are the ordinary strata still farther manufactured, (if we may be +allowed the expression) in the vicissitude of things, and by the mineral +operations of the globe. That those operations have been performed by +subterraneous heat has been already proved; but I would now mention some +particular appearances which are common or general to those strata, and +which can only be explained upon that principle. + +The red marly earth is prevalent among those strata; and it is with this +red ferruginous substance that many of the sand-stone strata are tinged. +It is plain that there had been an uniform, deposits of that sand and +tinging earth; and that, however different matter might be successively +deposited, yet that each individual stratum should be nearly of the same +colour or appearance, so far as it had been formed uniformly of the same +subsiding matter. But, in the most uniform strata of red sand-stone, +the fracture of the stone presents us with circular spots of a white or +bluish colour; those little spheres are in all respects the same with +the rest of the stone, they only want the tinging matter; and now it may +be inquired how this has come about. + +To say that sphericles of white sand should have been formed by +subsiding along with the red sand and earth which composed the uniform +stratum whether of sand-stone or marl, (for it happens equally in both,) +is plainly impossible, according to our notion of that operation in +which there is nothing mysterious. Those foliated strata, which are of +the most uniform nature, must have been gradually accumulated from the +subsiding sand and earth; and the white or colourless places must have +had their colour destroyed in the subsequent cementing operations. It +is often apparent, that the discharging operation had proceeded from a +centre, as some small matter may be perceived in that place. I know not +what species of substance this has been, whether saline or phlogistic, +but it must have had the power of either volatilising or changing the +ferruginous or red tinging substance so as to make it lose its colour. + +I have only mentioned spherical spots for distinctness sake; but this +discharging operation is found diversifying those strata in various +ways, but always referable to the same or similar causes. Thus, in many +of the veins or natural cracks of those strata, we find the colour +discharged for a certain space within the strata; and we often see +several of those spots united, each of them having proceeded from its +own centre, and uniting where they approached. In the two veins above +mentioned, of whin-stone and spar traversing the strata, the colour of +the strata is, discharged more or less in the places contiguous with the +veins. + +I am now to mention another appearance of a different kind. Those strata +of marl are in general not much consolidated; but among, them there +are sometimes found thin calcareous strata extremely consolidated, +consequently much divided by veins. It is in the solid parts of those +strata, perfectly disconnected from the veins, that there are frequent +cavities curiously lined with crystals of different sorts, generally +calcareous, sometimes containing also those that are siliceous, and +often accompanied with pyrites. I am persuaded that the origin of those +cavities may have been some hollow shells, such as _echini_ or some +marine object; but that calcareous body has been so changed, that it is +not now distinguishable; therefore, at present, I hold this opinion only +as conjecture. + +Having, in my return to Edinburgh, traveled up the Tiviot, with a view +to investigate this subject of primary and secondary operations of the +earth, I found the vertical strata, or alpine schistus, in the bed of +the river about two miles below Hawick. This was the third time I had +seen those vertical bodies after leaving the mountains of Lauderdale. +The first place was the bed of the river Tweed, at the new bridge below +Melrose; but here no other covering is to be seen above those vertical +strata besides the soil or traveled earth which conceals every thing +except the rock in the bed of the river. The second place was Jedburgh, +where I found the vertical strata covered with the horizontal sandstone +and marl, as has been now described. The third place was the Tiviot, and +this is that which now remains to be considered. + +Seeing the vertical strata in the bed of the river, I was desirous to +know if those were immediately covered with the horizontal strata. This +could not be discovered in the bed of the river where the rock was +covered upon the banks with travelled earth. I therefore left the river, +and followed the course of a brook which comes from the south side. I +had not gone far up the bank, or former boundary of the Tiviot, when +I had the satisfaction to find the vertical strata covered with the +pudding-stone and marly beds as in the valley of the Jed. + +It will now be reasonable to suppose that all the schistus which we +perceive, whether in the mountains or in the valleys, exposed to our +view had been once covered with those horizontal strata which are +observed in Berwickshire and Tiviotdale; and that, below all those +horizontal strata in the level country, there is at present a body or +basis of vertical or inclined schistus, on which the horizontal strata +of a secondary order had been deposited. This is the conclusion that I +had formed at Jedburgh, before I had seen the confirmation of it in the +Tiviot; it is the only one that can be formed according to this view of +things; and it must remain in the present state until more evidence be +found by which the probability may be either increased or diminished. + +Since writing this, I have read, in the Esprit de Journaux, an abstract +of a memoir of M. Voigt, upon the same subject, which I shall now +transcribe. + +"La mer a commence par miner les montagnes primitives dont les debris se +sont precipites au fond. Ces debris forment la premiere couche qui est +posee immediatement sur les montagnes primitives. D'apres l'ancien +langage de mineurs, nous avons jusqu'aujourd'hui appelle cette couche +_le sol mort rouge_, parce qu'il y a beaucoup de rouge dans son melange, +qu'elle forme le sol ou la base d'autres couches, et peut-etre de +toutes, qu'elle est entierement inutile et, en quelque facon, morte pour +l'exploitation des mines. Plusieurs se sont efforces de lui donner un +nom harmonieux; mais ils ne l'ont pu sans occasionner des equivoques. +Les mots _Breche Puddinstone Conglomerations_, &_c_. designent toujours +des substances autres que cette espece de pierre. + +"Il est tres agreable de l'examiner dans les endroits ou elle forme des +montagnes entieres. Cette couche est composee d'une quantite prodigieuse +de pierres arrondies, agglutinees ensemble par une substance argileuse +rouge et meme grise, et le toute a acquis assez de durete. On ne trouve +dans sa composition aucune espece de pierre qui, a en juger par les +meilleures observations, puisse avoir ete formee plus tard qu'elle; +on n'y voit par-tout que des parties et des produit des montagnes +primitives principalement de celles qui abondent le plus dans ces +contrees. Le sol mort, par exemple, qui compose les montagnes des +environs de Walbourg, pres d'Eisenach, contient une quantite de gros +morceaux de granit et de schiste micace; c'est vraisemblablement parce +que les montagnes primitives les plus voisines de Rhula, etc. sont, +pour la plus part, formees de ces deux especes de pierres. Pres de +Goldlauter, le sol mort consiste presque tout en porphyre, substance +dont sont formees les montagnes primitives qui y dominent; et le +Kiffauserberg dans la Thuringe a probablement recu ces morceaux arrondis +de schiste argileux des montagnes voisine du Hartz. Vous trouverez +ici que le schiste argileux existoit deja lorsque la mer a jette les +premiers fondemens de nos montagnes stratifiees. Je serois fort etonne +que quelqu'un me montrat un sol mort qui contint un morceaux de gypse, +de marne, de pierre puante et autres. Quoiqu'il en soit il n'est pas +aise d'expliquer pourquoi on ne trouve point de corps marins petrifies +dans cette espece de pierre. C'est peut-etre que, par l'immense quantite +de pierres dures roulees dans le fond de la mer, ils ont ete brises +avant qu'ils aient commence de s'agglutiner ensemble. Mais on rencontre +sur-tout au Kiffhauserberg des troncs d'arbres entiers petrifies; preuve +qu'il y avoit deja ou de la vegetation avant que l'ocean destructeur se +fut empare de ces cantons, ou du moins que quelques isles avoient existe +au-dessus de la surface." + +Here we find the same observations in the mountains of Germany that +I have been making with regard to those of Scotland. I have formerly +observed masses of the same kind in the west of England, to the east of +the Severn; but I could not discover any proper connection of that mass +with the regular strata. I have also long observed it in many parts of +Scotland, without being able to attain a sufficiently satisfactory idea +with regard to those particulars by which the alternation of land and +water, of the superficial and internal mineral operations of the globe, +might be investigated. + +It will be very remarkable if similar appearances are always found upon +the junction of the alpine with the level countries. Such an appearance, +I am inclined to think, may be found in the Val d'Aoste, near Yvree. M. +de Saussure describes such a stone as having been employed in building +the triumphal arch erected in honour of Augustus. "Cet arc qui etoit +anciennement revetu de marbre, est construit de grands quartiers d'une +espece assez singuliere de poudingue ou de gres a gros grains. C'est une +assemblage de fragmens, presque touts angulaires, de toutes sortes de +roches primitives feuilletees, quartzeuses, micacees; les plus gros de +ces fragmens n'atteignent pas le volume, d'une noisette. La plupart des +edifices antiques de la cite l'Aoste et de ses environs, sont construits +de cette matiere; et les gens du pays sont persuades que c'est une +composition; mais j'en ai trouve des rochers en place dans les montagnes +au nord et au-dessus de la route d'Yvree." + +We may now come to this general conclusion, that, in this example of +horizontal and posterior strata placed upon the vertical _schisti_ which +are prior in relation to the former, we obtain a further view into the +natural history of this earth, more than what appears in the simple +succession of one stratum above another. We know, in general, that all +the solid parts of this earth, which come to our view, have either +been formed originally by subsidence at the bottom of the sea, or been +transfused in a melted state from the mineral regions among those solid +bodies; but here we further learn, that the indurated and erected +strata, after being broken and washed by the moving waters, had again +been sunk below the sea, and had served as a bottom or basis on which to +form a new structure of strata; and also, that those new or posterior +strata had been indurated or cemented by the consolidating operations +of the mineral region, and elevated from the bottom of the sea into the +place of land, or considerably above the general surface of the waters. +It is thus that we may investigate particular operations in the general +progress of nature, which has for object to renovate the surface of the +earth necessarily wasted in the operation of a world sustaining plants +and animals. + +It is necessary to compare together every thing of this kind which +occurs; it is first necessary to ascertain the fact of their being a +prior and posterior formation of strata, with the mineral operations +for consolidating those bodies formed by collection of the moveable +materials; and, secondly, it is interesting to acquire all the data we +can in order to form a distinct judgment of that progress of nature in +which the solid body of our land is alternately removed from the bottom +of the sea into the atmosphere, and sunk again at the bottom of the sea. + +I shall now transcribe what M. Schreiber has wrote in relation to +this subject. It is in a memoir concerning the gold mine of Gardette, +published in the Journal de Physique. + +"Avant de quitter la montagne de la Gardette qu'il me soit permis de +rapporter une observation qui peut-etre n'est pas denuee de tout +interet pour les naturalistes; je l'ai faite dans une galerie a environ +cinquante-trois toises a l'ouest du principal puit laquelle a ete +poussee sur la ligne de reunion de la pierre calcaire, et du granit +feuillete ou gneiss pour fonder le filon dans cet endroit. Ce filon +a six pouces d'epaisseur, et consiste en quartz entre-mele d'ochre +martiale, de pyrite cuivreuse et galene. Cette derniere est souvent +recouverte de chaux de plomb grise, et de petits cristaux de mine de +plomb jaune donnant dans l'analyse un indice d'or. Ce filon finit a la +reunion de la pierre calcaire au gneiss. Cette reunion se fait ici dans +la direction d'une heure 6/8 de la boussole de raineur, et sous un +inclinaison, occidentale de 26 degres. + +"Mais ce qu'il y a de remarquable, c'est que le gneis ne participe en +rien de la pierre calcaire quoiqu'il n'en soit separe que par une couche +d'une pouce d'epaisseur de terre argileuse et calcaire, tandis que le +rocher calcaire renferme beaucoup de fragmens de granit et de gneis, +dans le voisinage de cette reunion. + +"Cette observation prouve incontestablement que le granit et le gneis +avoient deja acquis une durete capable de resister aux infiltration +des parties calcaire, et qu'ils existoient a-peu-pres tels qu'ils sont +aujourd'hui lorsque la pierre calcaire commenca a se former; autrement +elle n'auroit pu saisir et envelopper des morceaux detaches de ces +rochers auxquels on donne avec raison l'epithete de primitif ou de +premiere formation." + +M. Schreiber continues his reasoning upon those mineral appearances, in +adducing another argument, which I do not think equally conclusive. He +says, "Le filon de la Gardette devoit pareillement exister avant la +montagne calcaire, car s'il s'etoit forme apres, je ne voit pas la +raison pour laquelle il s'y seroit arrete court, et pourquoi il ne se +seroit pas prolonge dans cette espece de rocher." It is not necessary, +in the formation of a vein, that it should proceed in traversing all the +strata which then are superincumbent; it is reasonable to suppose, and +consistent with observation to find them stop short in proceeding from +one stratum to another. Had M. Schreiber found any pieces of the vein +contained in the calcareous rock, he would have had good reason for +that assertion; but, to conclude that fact from grounds which do not +necessarily imply it, is not to be permitted in sound reasoning, if +certainty is the object, and not mere probability. + + +SECT. II.--The Theory confirmed from Observations made on purpose to +elucidate the subject. + +Having got a distinct view of the primary and secondary mineral bodies +or strata of the globe, and having thus acquired a particular object to +inquire after, with a view to investigate or illustrate this piece of +natural history, I was considering where we might most probably succeed +in finding the junction of the low country strata and alpine schistus. +I inquired of Mr Hall of Whitehall, who had frequent opportunities of +traversing those mountains which lie between his house in the Merse and +Edinburgh; and I particularly entreated him to examine the bed of the +Whittater, which he executed to my satisfaction. + +Mr Hall having had occasion to examine the Pease and Tour burns, in +planning and superintending the great improvement of the post road upon +Sir James Hall's estate while Sir James was abroad, he informed me that +the junction of the schistus and sand-stone strata was to be found in +the Tour burn. Professor Playfair and I had been intending a visit to +Sir James Hall at Dunglass; and this was a motive, not so much to hasten +our visit, as to chose the most proper time for a mineral expedition +both upon the hills and along the sea shore. + +It was late in the spring 1788 when Sir James left town, and Mr Playfair +and I went to Dunglass about the beginning of June. We had exceeding +favourable weather during the most part of our expedition; and I now +propose to give an account of the result of our observations. + +Dunglass burn is the boundary between the counties of East Lothian and +Berwickshire; and it is almost the boundary between the vertical and +horizontal strata. To the north-west of this burn and beautiful dean are +situated the coal, lime-stone, marl, and sand-stone strata; they are +found stretching away along the shore in a very horizontal direction +for some time, but become more and more inclined as they approach the +schistus of which the hills of Lammermuir to the south are composed. + +Though the boundary between the two things here in question be easily +perceivable from the nature of the country at the first inspection, by +the rising of the hills, yet this does not lead one precisely to the +junction; and in the extensive common boundary of those two things, the +junction itself is only to be perceived in few places, where the rock is +washed bare by the rivers or the sea, and where this junction is exposed +naked to our view. The sea is here wearing away the coast; and the bank, +about 200 feet high, is gradually falling down, making in some places a +steep declivity, in others a perpendicular cliff. St Abb's Head and Fast +Castle are head lands projecting into the sea, and are the bulwarks of +this shore, which is embayed to the westward, where the sea preys upon +the horizontal strata. The solid strata are every where exposed either +in the cliff or on the shore; we were therefore certain of meeting with +the junction in going from Dunglass to Fast Castle, which is upon the +schistus. But this journey can only be made by sea; and we first set out +to examine the junction in the Tour and Pease burns, where we had been +informed it was to be found. + +In the bottom of those rivulets the sand-stone and marly strata appear +pretty much inclined, rising towards the schistus country. The two burns +unite before they come to the shore; and it is about midway between this +junction and the bridges which are thrown over those two hollows, that +the junction is to be found. + +The schistus strata here approach towards vertical; and the sand-stone +strata are greatly inclined. But this inclination of those two different +strata are in opposite directions; neither does the horizontal section +of those two different strata run parallel to the junction; that is to +say, the intersection of those two different strata is a line inclined +to the horizon. + +At Jedburgh the schistus was vertical, and the strata horizontal; and +there was interposed a compound bed of pudding-stone, formed of various +water-worn bodies, the gravel of the schistus strata, and porphyries. +Here again, though we have not a regular pudding-stone, we have +that which corresponds to it, as having been the effect of similar +circumstances. These are the fracture and detritus of the schistus, +while the strata were deposited upon the broken ends of the schistus at +the bottom of the sea. Most of the fragments of the schistus have their +angles sharp; consequently, they had not travelled far, or been much +worn by attrition. But more or less does not alter the nature of an +operation; and the pudding-stone, which at Jedburgh is interposed +between the vertical schistus and horizontal strata, is here properly +represented by the included fragments of schistus in the inclined +strata. + +The line of this junction running, on the one hand, towards Fast Castle +eastward, and, on the other, towards the head of Dunglass burn +westward, our business was to pursue this object in those two different +directions. But it was chiefly in the sea coast that was placed our +expectations, having recollection of the great banks of gravel under +which the strata are buried about Oldhamstocks, near which, from all +appearances, the junction was to be expected. + +Having taken boat at Dunglass burn, we set out to explore the coast; +and, we observed the horizontal sand-stone turn up near the Pease burn, +lifting towards the schistus. We found the junction of that schistus +with the red sand-stone and marly strata on the shore and sea bank, at +St. Helens, corresponding in general with what we had observed in the +burns to the westward. But, at Siccar Point, we found a beautiful +picture of this junction washed bare by the sea. The sand-stone strata +are partly washed away, and partly remaining upon the ends of the +vertical schistus; and, in many places, points of the schistus strata +are seen standing up through among the sand-stone, the greatest part of +which is worn away. Behind this again we have a natural section of those +sand-stone strata, containing fragments of the schistus. + +After this nothing appears but the schistus rocks, until sand-stone and +marl again are found at Red-heugh above the vertical strata. From that +bay to Fast Castle we had nothing to observe but the schistus, which is +continued without interruption to St Abb's Head. Beyond this, indeed, +there appears to be something above the schistus; and great blocks of a +red whin-stone or basaltes come down from the height and lie upon the +shore; but we could not perceive distinctly how the upper mass is +connected with the vertical schistus which is continued below. + +Our attention was now directed to what we could observe with respect +to the schisti, of which we had most beautiful views and most perfect +sections. Here are two objects to be held in view, in making those +observations; the original formation or stratification of the schisti, +and the posterior operations by which the present state of things has +been procured. We had remarkable examples for the illustration of both +those subjects. + +With regard to the first, we have every where among the rocks many +surfaces of the erected strata laid bare, in being separated. Here we +found the most distinct marks of strata of sand modified by moving +water. It is no other than that which we every day observe upon the +sands of our own shore, when the sea has ebbed and left them in a waved +figure, which cannot be mistaken. Such figures as these are extremely +common in our sand-stone strata; but this is an object which I never had +distinctly observed in the alpine schisti; although, considering that +the original of those schisti was strata of sand, and formed in water, +there was no reason to doubt of such a thing being found. But here the +examples are so many and so distinct, that it could not fail to give us +great satisfaction. + +We were no less gratified in our views with respect to the other object, +the mineral operations by which soft strata, regularly formed in +horizontal planes at the bottom of the sea, had been hardened and +displaced. Fig. 4. represents one of those examples; it was drawn by Sir +James Hall from a perfect section in the perpendicular cliff at Lumesden +burn. Here is not only a fine example of the bendings of the strata, but +also of a horizontal shift or hitch of those erected strata. + +St Abb's Head is a promontory which, at a distance, one would naturally +conclude to be composed of the schisti, as is all the shore to that +place; but, as we approached it, there was some difference to be +perceived in the external appearance, it having a more rounded and +irregular aspect. Accordingly, upon our arrival, we found this head-land +composed of a different substance. It is a great mass of red whin-stone, +of a very irregular structure and composition. Some of it is full of +small pebbles of calcareous spar, surrounded with a coat of a coloured +substance, different both from the whin-stone ground and the inclosed +pebble. Here ended our expedition by water. + +Having thus found the junction of the sand-stone with the schistus +or alpine strata to run in a line directed from Fast Castle to +Oldhamstocks, or the heads of Dunglass burn, we set out to trace this +burn, not only with a view to observe the junction, if it should there +appear, but particularly to discover the source of many blocks of +whin-stone, of all sizes, with which the bed of this burn abounds. + +The sand-stone and coal strata, which are nearly horizontal at the mouth +of this burn, or on the coast, become inclined as we go up the course of +the rivulet; and of this we have fine sections in the bank. The Dean of +Dunglass is formed of precipitous and perpendicular rocks, through which +the running water has worn its way more than a hundred feet deep; above +this Dean the banks are steep and very high, but covered with +soil, which here is a deep gravel. The burn runs all the way up to +Oldhamstocks upon the sand-stone strata; but there, these are traversed +by a high whin-stone dyke, which crosses the burn obliquely, as we found +it on both banks though not in the bed of the burn; it is in the south +bank below the village, and on the north above it. Here is the source +of the whin-stone which we were looking for; it is the common blue +basaltes, of the same nature with the Giant's Causeway, but with no +regular columner appearance. + +Above Oldhamstocks we again found the sand-stone in the bank, but it +soon disappeared under a deep cover of gravel, and the burn then divided +into several rivulets which come from the hills. We traced the one which +led most directly up to the mountains, in expectation of meeting with +the schistus, at least, if not the junction of it with the sandstone. +But in this we were disappointed. We did not however lose our labour; +for, though the junction which we pursued be not here visible, we met +with what made it sufficiently evident, and was at the same time an +object far more interesting in our eyes. + +I have already quoted Mr Voigt's description of the _sol mort rouge_; he +says, that in places it forms entire mountains; here we have a perfect +example of the same thing; and the moment we saw it, we said, here is +the _sol mort rouge_. We ascended to the top of the mountain through +a gully of solid pudding-stone going into decay, and furnishing the +country below with that great covering of gravel, soil, and water worn +stones. We were now well acquainted with the pudding-stone, which is +interposed between the horizontal and alpine strata; but from what we +had seen to the eastward, we never should have dreamed of meeting with +what we now perceived. What we had hitherto seen of this pudding-stone +was but a few fragments of the schistus in the lower beds of sand-stone; +here a mountain of water-worn schisti, imbedded in a red earth and +consolidated, presented itself to our view. It was evident that the +schisti mountains, from whence those fragments had come, had been prior +to this secondary mass; but here is a secondary mountain equal in height +to the primary, or schisti mountains, at the basis of which we had seen +the strata superinduced on the shore. Still, however, every thing here +is formed upon the same principle, and nothing here is altered except +the scale on which the operation had been performed. + +Upon the coast, we have but a specimen of the pudding-stone; most of +the fragments had their angles entire; and few of them are rounded by +attrition. Here, on the contrary, the mountain is one pudding-stone; +and most of the fragments are stones much rounded by attrition. But the +difference is only in degree, and not in kind; the stones are the same, +and the nature of the composition similar. Had we seen the mass of which +this mountain is only a relict, (having been degraded by the hands of +time), we should have found this pudding-stone at the bottom of +our sand-stone strata; could we have penetrated below this mass of +pudding-stone, we should have found our schistus which we left on the +shore at St. Helens and in the Tour burn. In Tiviotdale the vertical +schisti are covered with a bed of pudding-stone, the gravel of which had +been much worn by attrition, but the thickness of that bed is small; +here again the wearing operation has been great, and the quantity of +those materials even more than in proportion to those operations. We +returned perfectly satisfied; and Sir James Hall is to pursue this +subject farther when he shall be in those mountains shooting muir game. + +We had now only one object more to pursue; this was to examine the south +side of those mountains of Lammermuir upon the sea shore, in order +to see the junction of the primary schistus with the coal strata +of Berwickshire. Mr Hall was to meet us at the Press, and we were +afterwards to go with him to Whitehall. We met accordingly; but the +weather was rainy; and we went directly to Whitehall. I had often seen +the pudding-stone in great masse; in the banks of the Whiteader, as +it comes out of the mountains, but then I had not seen its connection +neither, on the one hand, with the schisti, nor, on the other, with the +sand-stone strata. We knew that at Lammerton upon the sea coast there +was coal, and consequently the sand-stone strata; and reasoning upon +those data we were sure that our proper course of investigation was to +trace the river Ey to the shore, and then go south the coast in search +of the junction of the schistus with the horizontal strata. This we +executed as well as the weather would permit; but had it to regret, +that the rainy season was not so favourable for our views, as it was +agreeable to the country which had been suffering with the drought. + +It is needless now to enlarge upon this subject. I shall only mention +that we found the red marly strata above the pudding-stone in the bed of +the Ey and its branches; we then traced the schistus down the Ey, and +found a mass of the most consolidated pudding-stone upon the coast to +the north of the harbour of Eymouth. But this mass did not rest on the +schistus; it is immediately upon a mass of whin-stone; and the schistus +is in the harbour, so that this whin-stone mass seems to be here +interposed between the pudding-stone and schistus. We then pursued +the coast southwards until we found the junction of the schistus and +sand-stone strata about two miles from Eymouth; but here the junction +was not attended with any pudding-stone that we could perceive. + +Having found the same or similar appearances from the one end to the +other, and on both sides of that range of mountains which run from sea +to sea in the south of Scotland, we may now extend our view of this +mineral operation in comprehending every thing of the same kind which we +meet with in our island or any other distant country. + +Thus perhaps the pudding-stone of the south of England will be +considered in the same light as having been formed of the _debri_ and +_detritus_ of the flinty bodies. + +In the island of Arran, there is also a pudding-stone, even in some +of the summits of the island, exactly upon the border of the schistus +district, as will be described in the natural history of that island. +This pudding-stone is composed of gravel formed of the hardest parts +of the schistus and granite or porphyry mountains. That compound +parasitical stone has been also again cemented by heat and fusion; I +have a specimen in which there is a clear demonstration of that fact. +One of the water-worn stones which had been rounded by attrition, has in +this pudding-stone been broken and shifted, the one half slipping over +the other, three quarters of an inch, besides other smaller slips in +the same stone. But the two pieces are again cemented; or they had been +shifted when the stone was in that soft state, by which the two pieces +are made perfectly to cohere. Those shifts and veins, in this species of +stone, are extremely instructive, illustrating the mineral operations of +the globe. + +In like manner to the north of the Grampians, along the south side of +Loch Ness, there are mountains formed of the debris of schistus and +granite mountains, first manufactured into sand and gravel, and then +consolidated into a pudding-stone, which is always formed upon the same +principle. The same is also found upon the south side of those mountains +in the shire of Angus. + +I may also give for example the African _Brechia_, which is a +pudding-stone of the same nature. This stone is composed of granites or +porphyries, serpentines and schisti, extremely indurated and perfectly +consolidated. It is also demonstrable from the appearance in this stone +that it has been in a softened state, from the shape and application +of its constituent parts; and in a specimen of it which I have in my +cabinet, there is also a demonstration of calcareous spar flowing among +the gravel of the consolidated rock. + +This fact therefore of pudding-stone mountains, is a general fact, so +far as it is founded upon observations that are made in Africa, Germany, +and Britain. We may now reason upon this general fact, in order to see +how far it countenances the idea of primitive mountains, on the one +hand, or on the other supports the present theory, which admits of +nothing primitive in the visible or examinable parts of the earth. + +To a person who examines accurately the composition of our mountains, +which occupy the south of Scotland, no argument needs be used to +persuade him that the bodies in question are not primitive; the thing +is evident from inspection, as much as would be the ruins of an ancient +city, although there were no record of its history. The visible +materials, which compose for the most part the strata of our south +alpine schisti, are so distinctly the _debris_ and _detritus_ of a +former earth, and so similar in their nature with those which for the +most part compose the strata on all hands acknowledged as secondary, +that there can remain no question upon that head. The consolidation, +again, of those strata, and the erection of them from their original +position, and from the place in which they had been formed, is another +question. + +But the acknowledging strata, which had been formed in the sea of loose +materials, to be consolidated and raised into the place of land, is +plainly giving up the idea of primitive mountains. The only question, +therefore, which remains to be solved, must respect the order of things, +in comparing the alpine schisti with the secondary strata; and this +indeed forms a curious subject of investigation. + +It is plain that the schisti had been indurated, elevated, broken, and +worn by attrition in water, before the secondary strata, which form the +most fertile parts of our earth, had existed. It is also certain that +the tops of our schistus mountains had been in the bottom of the sea +at the time when our secondary strata had begun to be formed; for the +pudding-stone on the top of our Lammermuir mountains, as well as the +secondary strata upon the vertical schisti of the Alps and German +mountains, affords the most irrefragable evidence of that fact. + +It is further to be affirmed, that this whole mass of water-formed +materials, as well as the basis on which it rested, had been subjected +to the mineral operations of the globe, operations by which the loose +and incoherent materials are consolidated, and that which was the bottom +of the sea made to occupy the station of land, and serve the purpose for +which it is destined in the world. This also will appear evident, when +it is considered that it has been from the appearances in this very +land, independent of those of the alpine schisti, that the present +theory has been established. + +By thus admitting a primary and secondary in the formation of our land, +the present theory will be confirmed in all its parts. For, nothing but +those vicissitudes, in which the old is worn and destroyed, and new +land formed to supply its place, can explain that order which is to be +perceived in all the works of nature; or give us any satisfactory +idea with regard to that apparent disorder and confusion, which would +disgrace an agent possessed of wisdom and working with design. + + + +CHAP. VII. + +Opinions examined with regard to Petrifaction, or Mineral Concretion. + +The ideas of naturalists with regard to petrifaction are so vague and +indistinct, that no proper answer can be given to them. They in general +suppose water to be the solvent of bodies, and the vehicle of petrifying +substances; but they neither say whether water be an universal +menstruum, nor do they show in what manner a solid body has been formed +in the bowels of the earth, from that solution. It may now be proper to +examine this subject, not with a view to explain all those petrifactions +of bodies which is performed in the mineral regions of the earth, those +regions that are inaccessible to man, but to show that what has been +wrote by naturalists, upon this subject, has only a tendency to corrupt +science, by admitting the grossest supposition in place of just +principle or truth, and to darken natural history by introducing an ill +conceived theory in place of matter of fact. + +M. le Comte de Buffon has attempted to explain the crystallization +of bodies, or production of mineral forms, by the accretion or +juxtaposition of elementary bodies, which have only form in two +dimensions, length and breadth; that is to say, that mineral concretions +are composed of surfaces alone, and not of bodies. This however is only +an attempt to explain, what we do not understand, by a proposition which +is either evidently contradictory, or plainly inconceivable. It is +true that this eloquent and ingenious author endeavours to correct the +palpable absurdity of the proposition, by representing the constituent +parts of the mineral bodies as "_de lames infiniment minces_;" but who +is it does not see, that these infinitely thin plates are no other than +bodies of three dimensions, contrary to the supposition; for, infinitely +thin, means a certain thickness; but the smallest possible or assignable +thickness differs as much from a perfect superficies as the greatest. + +M. de Luc has given us his ideas of petrifaction with sufficient +precision of term and clearness of expression; his opinion, therefore, +deserves to be examined; and, as his theory of petrifaction is equally +applicable to every species of substance, it is necessary again to +examine this subject, notwithstanding of what has been already said, +in the first part of this work, concerning consolidation and mineral +concretion from the fluid state of fusion. + +This author has perhaps properly exposed Woodward's Theory of +Petrification in saying[33], "Son erreur a cet egard vient de ce qu'il +n'a point reflechi sur la maniere dont se fait la _petrifaction_. Il +ramollit d'abord les _pierres_ pour y faire entrer les coquilles, sans +bien connoitre l'agent qu'il y employe; et il les duroit ensuite, sans +reflechir au comment." To avoid this error or defect, M. de Luc, in his +Theory of Petrifaction, sets out with the acknowledged principle of +cohesion; and, in order to consolidate strata of a porous texture, he +supposes water carrying minute bodies of all shapes and sizes, and +depositing them in such close contact as to produce solidity and +concretion. Now, if Dr Woodward softened stones without a proper +cause, M. de Luc, in employing the specious principle of cohesion, has +consolidated them upon no better grounds; for, the application of this +principle is as foreign to his purpose, as is that of magnetism. Bodies, +it is true, cohere when their surfaces are closely applied to each +other; But how apply this principle to consolidation?--only by supposing +all the separate bodies, of which the solid is to be composed, to be +in perfect contact in all their surfaces. But this, in other words, +is supposing the body to be solid; and, to suppose the agent, water, +capable of thus making hard bodies solid, is no other than having +recourse to the fortuitous concourse of atoms to make a world; a thought +which this author would surely hold in great contempt. + +[Note 33: Lettres Physiques et Morales.] + +He then illustrates this operation of nature by those of art, in +building walls which certainly become hard, and which, as our author +seems to think, become solid. But this is only an imperfect or erroneous +representation of this subject; for, mortar does not become hard upon +the principle of petrification adopted by our author. Mortar, made of +clay, instead of lime, will not acquire a stony hardness, nor ever, by +means of water, will it be more indurated than by simply drying; neither +will the most subtile powder of chalk, with water and sand, form any +solid body, or a proper mortar. The induration of mortar arises from the +solution of a stony substance, and the subsequent concretion of that +dissolved matter, operations purely chemical. Now, if this philosopher, +in his Theory of Petrifaction, means only to explain a chemical +operation upon mechanical principles, why have recourse, for an example +in this subject, to mineral bodies, the origin of which is questioned? +Why does he not rather explain, upon this principle, the known +concretion of some body, from a fluid state, or, conversely, the +known solution of some concreted body? If again he means to explain +petrifaction in the usual way, by a chemical operation, in that case, +the application of his polished surfaces, so as to cohere, cannot take +place until the dissolved body be separated from the fluid, by means of +which it is transported from place to place in the mineral regions. But +it is in this preliminary step that lies all the difficulty; for, could +we see how every different substance might be dissolved, and every +dissolved substance separated from its solvent at our pleasure, we +should find no difficulty in admitting the cohesion of hard bodies, +whether by means of this doctrine of polished surfaces, or by the +principle of general attraction, a principle which surely comprehends +this particular, termed a cohesive power. + +It must not be alleged, that seeing we know not how water dissolves +saline bodies, therefore, this fluid, for any thing that we know, may +also dissolve crystal; and, if water thus dissolves a mineral substance +in a manner unknown to us, it may in like manner deposit it, although +we may not be able to imagine how. This kind of reasoning is only +calculated to keep us in ignorance; at the same time, the reasoning of +philosophers, concerning petrifaction, does not in general appear to be +founded on any principle that is more sound. That water dissolves salt +is a fact. That water dissolves crystal is not a fact; therefore, those +two propositions, with regard to the power of water, are infinitely +removed, and cannot be assimilated in sound physical reasoning. It is +no more a truth that water is able to dissolve salt, than that we never +have been able to detect the smallest disposition in water to dissolve +crystal, flint, quartz, or metals. Therefore, to allege the possibility +of water being capable of dissolving those bodies in the mineral +regions, and of thus changing the substance of one body into another, as +naturalists have supposed, contrary to their knowledge, or in order to +explain appearances, is so far from tending to increase our science, +that it is abandoning the human intellect to be bewildered in an error; +it is the vain attempt of lulling to sleep the scientific conscience, +and making the soul of man insensible to the natural distress of +conscious ignorance. + +But besides that negative argument concerning the insolubility of +crystal, by which the erroneous suppositions of naturalists are to +be rejected, crystal in general is found regularly concreted in the +cavities of the most solid rock, in the heart of the closest agate, and +in the midst of granite mountains. But these masses of granite were +formed by fusion; I hope that I shall give the most satisfactory proof +of that truth: Consequently, here at least there is no occasion for the +action of water in dissolving siliceous substances in one place, in +order to concrete and crystallise it in another. + +In these cavities of the solid granite rock, where crystal is found +regularly shooting from a basis which is the internal surface of the +cavity, we find the other constituent substances of the granite also +crystallised. I have those small cavities, in this rock, from the island +of Arran, containing crystal, felt-spar, and mica, all crystallised in +the same cavity[34]. But this is nothing to the _druzen_ or crystalline +concretions, which are found in a similar manner among metallic and +mineral substances in the veins and mines; there, every species of +mineral and metallic substance, with every variety of mixture and +composition, are found both concreted and crystallised together in every +imaginable shape and situation. + +[Note 34: The Chevalier Dolomieu makes the following observation. +Journal de Physique, Juillet 1791. + +"J'ai ete etonne de trouver au centre d'un enorme massif de granit, que +l'on avoit ouvert avec la poudre pour pratiquer un chemin, des +morceaux, gros comme le poing et au dessous, de spath calcaire blanc, +tres-effervescent, en grandes ecailles, ou lames entrecroisees. Il +n'occupoit point des cavites particulieres, il n'y paroissoit le +produit d'une infiltration qui auroit rempli des cavites, mais il etoit +incorpore avec les feld-spath, le mica, et le quartz, faissoit masse +avec eux, et ne pouvoit se rompre sans les entrainer avec lui." + +This great naturalist is convinced that the spar had not been here +introduced by infiltration, although that is the very method which he +employs to form concretions, not only of spar but of crystal, zeolite, +and pyrites, in the closest cavities of the most solid rocks of +basaltes. These four substances in this stone were so mixed together +that nothing but the fusion of the whole mass could explain the state in +which they appeared; but, thinking that such a supposition could not +be allowed, this naturalist, like a man of science when his data fail, +leaves the matter without any interpretation of his own. This however is +what he has not done in the case of basaltes, or that which he mistakes +for proper lavas, as I shall have occasion to show.] + +Here is an infinite operation, but an operation which is easily +performed by the natural arrangement of substances acting freely in +a fluid state, and concreting together, each substance, whether more +simple or more compound, directing itself by its internal principle of +attraction, and affecting mechanically those that are concreting around +it. + +We see the very same thing happen under our eye, and precisely in the +same manner. When a fluid mass of any mineral or metallic substance is +made to congeal by sudden cooling on the outside, while the mass within +is fluid, a cavity is thus sometimes formed by the contraction of the +contained fluid; and in this cavity are found artificial _druzen_, as +they may be called, being crystallizations similar to those which the +mineral cavities exhibit in such beauty and perfection. + +Petrification and consolidation, in some degree, may doubtless be +performed, in certain circumstances, by means of the solution of +calcareous earth; but the examples given by M. de Luc, of those bodies +of lime-stone and agate petrified in the middle of strata of loose or +sandy materials, are certainly inexplicable upon any other principle +except the fusion of those substances with which the bodies are +petrified[35]. + +[Note 35: Vid. Lettre 28 et Lettre 103. Lettres Physiques et Morales.] + +This subject deserves the strictest attention; I propose it as a +touchstone for every theory of petrification or perfect consolidation. +First, There are found, among argillaceous strata, insulated bodies of +iron-stone, perfectly consolidated; secondly, There are found, in strata +of chalk and lime-stone, masses of insulated flints; thirdly, There +are found, in strata of sea sand, masses of that sand cemented by a +siliceous substance; fourthly, In the midst of blocks of sand-stone, +there are found masses of loose or pure sand inclosed in crystallised +cavities; and in this sand are found insulated masses of crystallised +spar, including within them the sand, but without having the sparry +or calcareous crystallization disturbed by it. There are also other +globular masses of the same kind, where the sparry crystallization is +either not to be observed, or appears only partially[36]: And now, +lastly, In strata of shell-sand, there are found masses of consolidated +lime-stone or marble. In all those cases, the consolidated bodies are +perfectly insulated in the middle of strata, in which they must of +necessity have been petrified or consolidated; the stratum around the +bodies has not been affected by the petrifying substance, as there +is not any vestige of it there; and here are examples of different +substances, all conspiring to prove one uniform truth. Therefore, a +general theory of petrification or consolidation of mineral bodies must +explain this distinct fact, and not suffer it any longer to remain a +_lusus naturae_. + +[Note 36: Mem. de l'Academie Royale des Sciences, an. 1775.] + +Let us now consider what it is that we have to explain, upon the +supposition of those concretions being formed from a solution. We have, +first, To understand what sort of a solution had been employed for the +introducing of those various substances; secondly, How those concretions +had been formed from such solutions within those bodies of strata; and, +lastly, How such concretions could have been formed, without any vestige +appearing of the same substance, or of the same operation, in the +surrounding part of the stratum. Whatever may be the difficulty +of explaining those particular appearances by means of fusion and +mechanical force, it is plainly impossible to conceive those bodies +formed in those places by infiltration, or any manner of concretion from +a state of solution. + +Naturalists, in explaining the formation of stones, often use a chemical +language which either has no proper meaning, or which will not apply to +the subject of mineral operations. We know the chemical process by which +one or two stony concretions may be formed among bodies passing from +one state to another. When, therefore, a change from a former state of +things in mineral bodies is judged by naturalists to have happened, the +present state is commonly explained, or the change is supposed to have +been made by means of a similar process, without inquiring if this had +truly been the case or not. Thus their knowledge of chemistry has led +naturalists to reason erroneously, in explaining things upon false +principles. It would be needless to give an example of any one +particular author in this respect; for, so far as I have seen, it +appears to be almost general, every one copying the language of another, +and no one understanding that language which has been employed. + +These naturalists suppose every thing done by means of solution in the +mineral kingdom, and yet they are ignorant of those solvents. They +conceive or they imagine concretions and crystallizations to be formed +of every different substance, and in every place within the solid body +of the earth, without considering how far the thing is possible which +they suppose. They are constantly talking of operations which could only +take place in the cavities of the earth above the level of the sea, and +where the influence of the atmosphere were felt; and yet this is the +very place which we have it in our power to examine, and where, besides +the stalactite, and one or two more of the same kind, or formed on the +same principle, they have never been able to discover one of the many +which, according to their theory, ought always to be in action or +effect. So far from knowing that general consolidating operation, which +they suppose to be exerted in filling up the veins and cavities of the +earth by means of the infiltrating water of the surface, they do not +seem fully to understand the only operation of this kind which they see. +The concretion of calcareous matter upon the surface of the earth is +perhaps the only example upon which their theory is founded; and +yet nothing can be more against it than the general history of this +transaction. + +Calcareous matter, the great _vinculum_ of many mineral bodies, is in +a perpetual state of dissolution and decay, in every place where the +influences of air and water may pervade. The general tendency of this +is to dissolve calcareous matter out of the earth, and deliver that +solution into the sea. Were it possible to deny that truth, the +very formation of stalactite, that operation which has bewildered +naturalists, would prove it; for it is upon the general solubility of +calcareous matter exposed to water that those cavities are formed, in +which may be found such collections of stalactical concretion; and the +general tendency of those operations is to waste the calcareous bodies +through which water percolates. But how is the general petrifaction or +consolidation of strata, below the surface of the sea, to be explained +by the general dissolution of that consolidating substance in the +earth above that level? Instead of finding a general petrifying or +consolidating operation in the part of the earth which we are able to +examine, we find the contrary operation, so far at least as relates to +calcareous spar, and many other mineral bodies which are decomposed and +dissolved upon the surface of the earth. + +Thus in the surface of the earth, above the level of the sea, no +petrifying operation of a durable nature is found; and, were such an +operation there found, it could not be general, as affecting every kind +of substance. But, even suppose that such a general operation were found +to take place in the earth above the level of the sea, where there might +be a circulation of air and percolation of water, How could the strata +of the earth below the level of the sea be petrified? This is a question +that does not seem to have entered into the heads of our naturalists +who attempt to explain petrifaction or mineral concretion from aqueous +solutions. But the consolidation of loose and incoherent things, +gathered together at the bottom of the sea, and afterwards raised +into rocks of various sorts, forms by far the greatest example of +petrification or mineral operation of this globe. It is this that must +be explained in a mineral theory; and it is this great process of +petrifaction to which the doctrine of infiltration, whether for the +mechanical purpose of applying cohesive surfaces, or the chemical one of +forming crystallizations and concretions, will not by any means apply. + +Nothing shows more how little true science has been employed for the +explanation of phenomena, than the language of modern naturalists, who +attribute, to stalactical and stalagmical operations, every superficial +or distant resemblance to those calcareous bodies, the origin of which +we know so well. It is not a mere resemblance that should homologate +different things; there should be a specific character in every thing +that is to be generalised. It will be our business to show that, in the +false stalactites, there is not the distinctive character of those water +formed bodies to be found. + +In the formation of stalactical concretions, besides the incrustation as +well as crystallization of the stony substance from the aqueous vehicle +by which it had been carried in the dissolved state, we have the other +necessary accompanyments of the operation, or collateral circumstances +of the case. Such, for example, is that tubular construction of the +stalactite, first formed by the concretion of the calcareous substance +upon the outside of the pendant gut of water exposed to the evaporation +of the atmosphere; we then see the gradual filling up of that pervious +tube through which the petrifying water had passed for a certain time; +and, lastly, we see the continual accretion which this conducting body +had received from the water running successively over every part of +it. But among the infinite number of siliceous concretions and +crystallizations, as well as those of an almost indefinite variety of +other substances, all of which are attributed to solution, there is not +the least vestige of any collateral operation, by which the nature of +that concretion might be ascertained in the same manner. In all +those cases, we see nothing but the concreted substances or their +crystallizations; but, no mark of any solvent or incrusting process is +to be perceived. On the contrary, almost all, or the greatest part +of them, are so situated, and attended with such circumstances, as +demonstrate the physical impossibility of that being the manner in which +they had been concreted; for, they are situated within close cavities, +through which nothing can pervade but heat, electricity, magnetism, +etc.; and they fill those cavities more or less, from the thinnest +incrustation of crystals to the full content of those cavities with +various substances, all regularly concreted or crystallised according to +an order which cannot apply to the concretion of any manner of solution. + +That there is, in the mineral system, an operation of water which may +with great propriety be termed _infiltration_, I make no doubt. But this +operation of water, that may be employed in consolidating the strata +in the mineral regions, is essentially different from that which is +inconsiderately employed or supposed by mineralists when they talk +of infiltration; these two operations have nothing in common except +employing the water of the surface of the earth to percolate a porous +body. Now, the percolation of water may increase the porousness of that +body which it pervades, but never can thus change it from a porous to a +perfect solid body. But even the percolation of water through the strata +deposited at the bottom of the sea, necessarily required, according to +the supposition of naturalists, must be refused; for, the interstices of +those strata are, from the supposition of the case, already filled with +water; consequently, without first removing that stagnant water, it is +in vain to propose the infiltration of any fluid from the surface. + +This is a difficulty which does not occur in our theory, where the +strata, deposited at the bottom of the sea, are to be afterwards heated +by the internal fires of the earth. The natural consequence of those +heating operations may be considered as the converting of the water +contained in the strata into steam, and the expulsion of steam or +vapour, by raising it up against the power of gravity, to be delivered +upon the surface of the earth and again condensed to the state of water. + +Let us now conceive the strata, which had been deposited at the bottom +of the sea, as exhausted of their water, and as communicating with the +surface of the earth impregnated with water. Here again we have the +power of gravity to operate in carrying down water to that place which +had been before exhausted by the power of heat; and in this manner, by +alternately employing those two great physical agents, we cannot doubt +that nature may convey soluble substances from above, and deposit them +below for the purpose of consolidating porous bodies, or of filling with +saline and earthy matter those interstices which had been originally +filled with water, when the strata were deposited at the bottom of the +sea. How far any marks of this operation may be perceived, by carefully +examining our mines and minerals, I know not; I can only say that, on +the contrary, whenever those examined objects were clear and distinct, +with the concomitant circumstances, so as to be understood, I have +always found the most certain marks of the solid bodies having concreted +from the fluid state of fusion. This, however, does not exclude the case +of infiltration having been previously employed; and I would intreat +mineralists, who have the opportunity of examining the solid parts of +the earth, to attend particularly to this distinction. But do not let +them suppose that infiltration can be made to fill either the pores or +veins of strata without the operation of mineral heat, or some such +process by which the aqueous vehicle may be discharged. + +Not only are mineral philosophers so inconsiderate, in forming +geological theories upon a mere supposition or false analogy, they +have even proceeded, upon that erroneous theory, to form a geological +supposition for explaining the appearances of strata and other stony +masses in employing a particular physical operation, which is, that +of _crystallization_[37]. Now crystallization may be considered as a +species of elective concretion, by which every particular substance, in +passing from a fluid to a solid state, may assume a certain peculiar +external shape and internal arrangement of its parts, by which it is +often distinguished. But, to suppose the solid mineral structure of the +earth explained, like an enigma, by the word _crystallization_, is to +misunderstand the science by which we would explain the subject of +research; and, to form a general mineral theory thus upon that term, +is an attempt to generalise without a reason. For, when it were even +admitted that every solid body is crystallised, we thus know no more of +the geology of this earth, or understand as little of the general theory +of mineral concretion, as we did before;--we cannot, from that, say +whether it be by the operation of solution or of fusion which had +produced the perceived effect. + +[Note 37: Journal de Physique; Avril 1753.] + +M. de Carosi has wrote a treatise upon certain petrifactions[38]. In the +doctrine of this treatise there is something new or extraordinary. It +will therefore be proper to make some observations on it. + +[Note 38: Sur la Generation du Silex et du Quartz en partie. +Observations faites en Pologne 1783, a Cracovie.] + +The object of this treatise is to describe the generation of silex and +quartz, with their modifications or compositions, formed within mineral +bodies of a different substance. The natural history contained in this +little treatise is well described and sufficiently interesting. But It +is chiefly in order to examine the means which, according to the theory +of this treatise, are employed in petrifying bodies, that I consider it +in this place. + +The first section of this treatise has for title, _Generation du Caillou +et du Quartz de la terre calcaire pure_. It may be worth while to +compare the natural history of this part of the earth with the flint and +chert found in our chalk and lime-stone countries. I shall therefore +transcribe what is worth observing upon that subject (p. 5.). + +"Nous rencontrons chez nous dans les parties le plus montagneuses, et +les moins couvertes de terreau, ou tout-au plus de sable, entre de purs +rochers calcaires une quantite incroyable de cailloux (silex) tant en +boules, que veines, couches, et debris. Au premier coup d'oeil l'on +s'imagine que ce font des debris de montagnes eloignees, qui y furent +amenes par les eaux, mais, en examinant la chose de plus pres, on est +convaincu, que ce sont tout au contraire, des parties detachees des +montagnes de la contree. Car il y a sur presque toute l'etendue de nos +montagnes calcaires une couche, ou pour mieux dire, un banc compose +de plusieurs couches de base calcaire, mais qui ou sont parsemees +irregulierement de boules, de rognons, de veines, et de petits filons +de silex, ou qui contiennent cette pierre en filon, veines, et couches +paralleles, et regulierement disposees. Les boules et rognons de silex +y font depuis moins de la grandeur d'une petite noisette, jusqu'au +diametre de plus de six pouces de notre mesure. La plupart de ces boules +tant qu'elles sont dans l'interieur cache de la roche vive, et qu'elles +n'ont rien souffert de l'impression de l'air, ont, pour l'ordinaire, une +croute de spath calcaire, au moyen de la quelle elles sont accrues a +la roche mere; ou pour mieux dire la croute spatheuse fait l'intermede +entre le silex, et la roche calcaire, par ou se fait le passage de l'une +a l'autre. Mais ceci ne vaut que de boules de silex entierement formees. +C'est dont on peut meme se convaincre a la vue, par beaucoup de pierres +dont le pave de la ville de Cracovie est compose. Mais la, ou le silex +n'est pas encore entierement acheve, la croute spatheuse manque, en +revanche on y voit evidemment le passage par degres successifs de la +roche calcaire au silex qui y est contenu, et les nuances de ce passage +sont souvent si peu marquees que meme les acides mineraux ne suffisent +pas a les determiner, ce n'est que le briquet, qui nous aide a les +decouvrir. On voit bien ou la pierre calcaire s'enfonce en couleur, l'on +s'appercoit, ou sa durete, ses cassures changent, mais, comme elle y +souffre encore quelque impression des acides, l'on ne sauroit determiner +au juste le point, ou elle a deja plus de la nature du silex, que de +celle de la chaux, qu'en la frappant du briquet. + +"Tels sont les cailloux en boules et rognons avant leur etat de +perfection, il y aura meme au milieu une partie de pierre calcaire non +changee. + +"Ceux au contraire, ou la nature a acheve son ouvrage, ont une croute de +chaux endurcie, et sont purement du silex fini, mais de toutes couleurs, +d'un grain et d'une texture plus ou moins fine, qui passe assez souvent +par degres dans les differentes varietes du noble silex. Ils ont, pour +l'ordinaire, dans leur interieur une cavite, mais pas toujours au +centre, et qui vient apparemment de la consommation de cette partie +calcaire qui y resta la derniere, et n'en fut changee ou dissolute et +separee, que lorsque le reste du silex etoit deja entierement fini. Ces +cavites sont toujours, ou enduites de calcedoine en couche concentriques +recouverte de petits cristaux fort brillans et durs de quartz, ou bien +seulement de ces derniers-ci. Par-fois il y a aussi du spath calcaire +crystallise, mais cela est extremement rare. Quelque-fois enfin ces +cavites sont remplies d'une noix de calcedoine. Je n'ai reussi qu'une +seule fois en cassant un pareil silex en boule d'y trouver encore le +reste de l'eau de crystallisation." + +The only remark that I would here make is this, that, if the +crystallization of those close cavities in the _silex_ had at any time +required water of solution, it must always have required it. But, if +there had been water of solution contained in those close cavities, for +the crystallization of the various things which are often found within +them, How comes it that this water is almost never found? I have good +reason to believe that water contained within a solid flint will not +make its escape, as does that contained in the _anhydrites_ of Mount +_Berico_, which are composed of a porous calcedony. But the siliceous +crystallizations within close cavities is a curious subject, which we +shall have occasion to examine more particularly in treating of agates. +We now proceed to the next section, which is the generation of silex and +quartz in marl, (p. 19.) + +"Il y a des contrees, chez nous, qui out des etendus assez considerables +en long et en large, de montagnes de pierre de marne calcaire, dans +lesquelles on rencontre le meme phenomene que dans celles de chaux pure; +c. a. d. nous y trouvons du silex de differentes varietes, et dans tous +les degres successifs de leur formation, et de leur perfection. Outre +cela, nous y voyons encore quelque chose, qui semble nous conduire a +la decouverte des moyens, dont se sort la nature pour effecteur cette +operation, et qui nous etoit cache dans les montagnes de chaux pure: ces +bancs de pierre marnesilicieuse, contiennent une partie considerable de +pyrites sulfureuses, qui non seulement y forment une grande quantite +de petits sillons, mais toute la masse de la montagne est rempli de +parcelles souvent presqu'imperceptibles de ce mineral. Ces pyrites sont +evidemment des productions du phlogistique et de l'acide contenu dans la +montagne. + +"L'eau, qui s'y trouve ordinairement en assez grande abondance, en +detacha, extraha d'un et l'autre, et les combina apres tous les deux +ensemble. Cette meme eau les dissout derechef, et en fait de nouvelles +combinaisons. C'est ce qu'on voit evidemment la, ou la nature, ayant +commence ses operations, il n'y est reste de la pyrite, qu'une portion +de la partie inflammable liee a une base terrestre. Dans ces endroits +la marne n'est que fort peu sensible aux acides, et de blanche qu'elle +etoit, sa couleur est devenue presque noire. C'est la qu'on observe les +differens degres du changement de la marne en silex, contenant, meme +encore, par fois, de parties pyriteiques non detruites dans son +interieur. Et comme la nature forme ici, de meme, que dans la chaux pure +les silex, la plupart en boules ou rognons; comme les different degres +de metamorphoses de la marne en silex, sont ici beaucoup plus nombreuses +que la, de sorte qu'il y a des bandes entieres, qui meriteroient plutot +d'etre appelles bandes silicieuses, que marneuses; comme il y a, enfin, +une grande quantite de pyrites, qu'ailleurs, il est tres probable +qu'elle se serve la du meme moyen qu'ici pour operer la metamorphose en +question. + +"Ne nous precipitons, cependant, pas a en tirer plus de consequences; +poursuivons plutot le fil de notre recit. + +"Le silex, qui se trouve ici, est non seulement de differents degres de +perfection, il est de plus d'une espece. Il y a de la pierre a feu, 2 de +la calcedoine, 3 des agathes, et 4 differentes nuances et passages des +especes ordinaires aux fines du silex. + +"La pierre a feu, est, ordinairement dans son etat de perfection d'un +grain assez fin, d'une couleur grise plus ou moins foncee, et meme +donnant, dans le noiratre, plus ou moins diaphane; ses cassures sont +concentriques ou coquillees, et sa masse est assez compacte. Outre sa +conformation ordinaire en boules et rognons, elle fait presque toujours +la noix de ursins marins, qui y font en grand nombre, et dont la +coquille est le plus souvent, et presque toujours de spath calcaire, +meme au milieu d'une boule de silex parfait. + +"Les calcedoines et agathes de ces couches sont toujours (au moins, je +ne les ai pas encore vues autrement) de coraux et autres corps marins +petrifies. Donc, il faut que les couches de pierres roulees, d'ou j'ai +tire ma collection citee plus haut, soyent des debris de montagne" +detruites de cette espece. Il y en a qui sont tres parfaites comme +celles qui composent ma collection, d'autres meritent plutot d'etre +rangees parmi les passages du silex ordinaire, et ses especes plus +fines; d'autres encore sont, en effet, de vraies agathes, mais qui +renferment dans leur interieur plus ou moins de parties non parfaites +presque calcaires, qui s'annoncent d'abord par leur couleur blanche, +par leur gros grains relativement au reste, par leur opacite, par leur +mollesse respective, et souvent meme par leur sensibilite pour les +acides mineraux. Mais celles, qui sont finies, quoiqu'elles ayent, pour +la plupart, une couleur presque noire, ne laissent, cependant, pas +d'avoir aussi des teintes plus claires comme brunatres, verdatres, +rougeatres, jaunatres, bleuatres, tachetees, veinees, etc. Leur clarte +n'est pas moins variable, que leur couleur, il y en a de presqu'opaques, +comme aussi de presque transparentes, sur tout la, ou la calcedoine +predomine. + +"Le quartz s'y trouve comme dans les pierres de la premiere section, c, +a, d, crystallise, en groupes dans de petites cavites; quelquefois aussi +en veines. La calcedoine y est de meme, ou bien en mamelons, ou bien en +stalactites, lorsqu'elle a de la place pour s'y deposer. + +"Un phenomene encore plus curieux que cela est cette belle pyrite +sulphureuse jaune, comme de l'or, qui est quelquefois parsemee par tout +la substance de petrifications agathisees, et qui apparemment y fut +deposee apres la dite metamorphose a la faveur des petits pores, qui y +etoient restes ouverts." + +I would beg that mineralists, who use such language as this, would +consider if it contains a distinct idea of the operation which they +would thereby describe, or if it does not contain either a contradiction +or an inconceivable proposition. It supposes a calcareous body to be +metamorphosed, somehow by means of the mountain acid, into a siliceous +body. But, finding many bodies of pyrites contained within that solid +flint, it is said, that, when the calcareous body was flintified, there +were left in it cavities which were afterwards filled with pyrites. Let +us reflect a moment upon this doctrine. These cavities were first open +to the outside of the flinty body; but now the pyrites with which they +had been filled is insulated in the solid flint. Here three things are +required; first, The calcareous body is to be flintified, at the same +time leaving the body full of small cavities open to the outside; +secondly, These cavities are to be filled with pyrites; lastly, These +mineral bodies are to be so inclosed within the flint, as to leave no +vestige of the former processes. This marly mountain itself, which had +been formed of loose materials gathered together at the bottom of the +sea, was first to be filled with pyrites, in various shapes, by means of +the phlogistic and the acid of the mountain. Here is proposed to us an +operation which is totally unknown, or of which we have no kind of +idea. But, let us suppose pyrites formed in this mountain, (of whatever +chemical substances), by means of water; Why should water again undo +that pyrites, in order to form other concretions? And, Why should the +flint be formed first with cavities, and then made solid, after pyrites +had been introduced into those cavities of the agate, and, as our author +expresses it, _parsemee pour toute la substance?_ Here are suppositions +which are not only perfectly gratuitous, but are also inconsistent with +any thing that we understand. This is not explaining nature; it is only +feigning causes[39]. + +[Note 39: The description of those insulated siliceous bodies, +containing in their closed cavities all the usual concretions of +calcedony and crystals, as well as full of small pyrites floating in the +solid flint, are extremely interesting to a mineral system, or such a +geological theory as should explain the present state of things in those +strata that had been formed by deposits of known materials at the bottom +of the sea; they are indeed such appearances as may be found, more or +less, in all consolidated strata. But it is this author's explanation of +that petrifaction which is our present object to consider; and, as he is +so particular in giving us his theory upon the subject, it is easy to +detect the error of his reasoning. Were those naturalists who explain +things only in general, by saying that water is the agent, and +infiltration the means employed by nature;--were these naturalists, I +say, to give us as particular a description of their process, it would +appear as inconsistent with the nature of things as that which we have +from this author, who examines nature very minutely, and who sees +distinctly that the infiltrating theory is inapplicable for the +explanation of those petrifactions.] + +The third section has for title, "_Generation du Silex et Quartz de la +Pierre Puante_." Here we find an example worthy of being recorded, +as contributing to throw great light upon those mineral operations; +however, the opinion of our author and mine, upon this subject, differ +widely. He proceeds thus: + +"Cette pierre n'est, comme chacun le scait, qu'une pierre calcaire +contenant du bitume. + +"Nos montagnes n'en contiennent seulement pas de simples couches, mais +il y en a meme de grandes bancs fort epais. + +"Le caillou, ou silex qui s'y genere, forme, tantot de gros blocs +informes, qui occupent des cavites dans l'interieure des montagnes, +tantot, enfin, en forme de filons. + +"J'ai remarque cette metamorphose sur trois endroits differens, dans +chacun des quels la nature a autrement opere. + +"Sur l'un, la pierre puante fait un banc horizontal dans une montagne de +pierre calcaire crystalline, ou d'une espece de marbre, qui contient +des couches et filons de metal. Ce banc de pierre puante y fait le toit +d'une couche de galene de plomb et de pierre calaminaire, et dans ses +cavites et fentes il y a non seulement des blocs de grandeur differente, +mais aussi des veines et petites bandes courtes de silex, tant +ordinaire, que noble c, a, d, de la pierre a feu, de calcedoine, +d'agathes, et meme d'une espece de cornaline jaune et rouge pale. Je ne +m'arreterai pas a en detailler les varietes, parce qu'elles sont trop +accidentelles. Je ne les connois pas meme toutes, il s'en faut de +beaucoup, parce qu'elles se trouvent dans des anciennes mines negligees, +peut etre depuis plus d'un siecle, et par consequent peu accessibles. Je +ne doute, cependant pas, que, si l'on pouvoit mieux sonder le terrain, +on y trouveroit bien plus encore du peu que j'ai cite. Parmi ce silex, +il y a aussi de petites groupes et de petites veines de quartz solide et +crystallise. + +"Au second endroit la pierre puante fait un filon, ou si l'on veut, +une couche ou bande verticale, qui partage la montagne en deux parties +presqu'egales de l'epaisseur de trois aunes a peu pres. La montagne, +ou cela se voit est aussi une ancienne mine de cuivre et de plomb, +consistant en plusieurs varietes de marbre, different en couleur et en +grain, deposees par couches les unes sur les autres. Le filon de silex +est forme de feuilles alternatives de pierre puante et de silex, tous +les deux de couleur brun de bois a peu pres; mais le silex est plus +fonce que sa compagne. Ces feuilles alternatives, consistent d'autres +bien plus minces encore, qui souvent n'ont pas l'epaisseur d'une ligne, +mais ce qu'il y a de plus curieux, c'est que la meme feuille est d'un +but de pierre porque, qui, vers le milieu, passe successivement en +silex, qui, a son tour, vers l'autre but, qui etoit expose a l'air +repasse par les memes gradations en une espece de tuffe calcaire. Ce qui +nous fait voir evidemment la generation et la destruction du silex, meme +avec une partie des moyens par lesquels elle s'opere. Comme l'endroit de +cette decouverte n'est accessible qu'a la superficie, je ne saurois dire +s'il y a d'autres varietes de silex outre la dite. Il l'est a supposer +autant par analogie, que par quelques morceaux qui ont de petites veines +transversales d'une espece de calcedoine, et qui sont, meme, sur leur +fentes, garnis de petits cristaux de roche. Mais ce qu'il y a de sur +c'est que ce filon, parvenu a une certaine profondeur, s'ennoblit et +contient du metal, c. a. d. de la galene de plomb, et de la pyrite +cuivreuse, j'y en ai trouves de morceaux, qui en font de preuves +incontestables. Le caillou d'ici est un grain fin d'une texture forte, +peu transparent, donne beaucoup d'etincelles au briquet, mais ses +cassures sont ecailleuses. + +"La montagne calcaire du troisieme lieu a une couche de pierre puante +epaisse de plusieurs aunes, qui, derechef contient de petites couches +irregulieres et des bandes transversales de silex, qui ont jusques a +six pouces passes d'epaisseur. La pierre puante est d'une couleur +gris-brune, d'un grain assez fin, et d'un tissu assez dur; ses cassures +sont irregulieres, mais plus la pierre s'approche du silex, plus elles +donnent dans le coquille. Le silex ordinaire est d'un brun de bois, d'un +grain assez fin, et d'un tissu resistant, et ses cassures sont egales a +la pierre porque. Ce n'est pas la la seule variete, il y a, aussi, de la +calcedoine et des agathes de couleurs differentes. Meme la pierre a +feu est assez souvent traversee de veines de calcedoine, de quartz +crystallise, et de spath calcaire blanc en feuilles et en crystaux. Il +arrive que la meme veine est composee de ces trois especes de pierres a +la fois, de sorte que l'une semble passer dans l'autre, parce que les +limites reciproques sont, souvent, assez indistinctes. Il est evident, +que le silex est forme de la pierre puante, parce qu'on remarque ici +les memes phenomenes dont j'ai parle plus haut, c. a. d. les passages +successifs de l'une dans l'autre pierre, tant en montant qu'en +descendant." + +There is nothing particular in the siliceous mixture in this species of +lime-stone, except the vein of that substance. It is evident that this +vein, traversing the mountain, had been introduced in the fluid state +of fusion. I do not mean to say, that, in this particular case now +described, the evidence of that truth peculiarly appears; but that, from +the general nature of mineral veins breaking and traversing the solid +strata of the globe, no other conclusion can be formed; and that in +the particulars of this example there is nothing that could lead us to +suppose any other origin to the petrifactions contained in this vein +of stinking lime-stone. It is plain, that our author has imagined to +himself an unknown manner of executing his mineral metamorphoses. He +sees plainly that the common notion of infiltration will not at all +explain the evident confusion of those calcareous and siliceous bodies +which appear to him to be metamorphosing into each other. Nothing, +indeed, can explain those phenomena but a general cause of fluidity; and +there is no such general cause besides that of heat or fusion. + +But to show how mineralists of great merit, gentlemen who have examined +systematically and with some accuracy, may impose upon themselves in +reasoning for the explanation of mineral appearances from limited +notions of things, and from the supposition of these having been formed +where they now are found, that is, upon the surface of the earth, I +would beg leave to transcribe what this author has said upon this +species of petrifaction. It is not that he is ignorant of what +mineralists have already said upon the subject; it is because he sees +the incompetency of their explanations in those particular cases; and +that he would employ some other more effectual means. (p. 50.) + +"Toute terre calcaire a changer dans une autre doit, avant toute chose, +etre rendue refractaire ce qui ne peut se faire qu'en la saturant avec +un acide. Mais une terre simplement, saturee d'un acide, est d'une +reduction fort aisee, vu que l'acide n'y tient pas trop fort, d'ailleurs +ce n'est qu'un sel neutre terreux fort facile a dissoudre dans une +quantite suffisante d'eau. Or pour rendre cette union plus constante, il +faut que la terre alcaline s'assimile intimement a l'acide, ce qui ne +se sera jamais sans un intermedeliant, qui homogene les parties de ce +nouveau corps, et pour que cela ce fasse il est indispensable, qu'il +s'opere une dissolution fonciere des parties terrestres de la chaux, qui +facilite l'ingress a l'acide, et a l'intermede pour qu'ils s'y lie bien +fortement. Supposons qu'il se forme une liqueur savonneuse de l'acide et +du phlogistique, que l'air fixe, mis en liberte, ouvre les interstices +des parties qui constituent la terre alcaline, qu'apres cela cette +liqueur savonneuse ayant l'entree libre s'assimile a la terre en +proportion requise, que l'eau, qui servoit de vehicule dans cette +operation, s'evapore successivement, et emporte le superflu des +ingrediens, pour qu'il se puisse operer le rapprochement le plus exacte +des parcelles ou molecules homogenees de nouveau corps qu'enfin les +molecules les plus pures et les mieux affinees soyent reunies en forme +liquide dans des cavites, et que par l'evaporation et separation de +l'eau, ou elles nageoient, il s'en forme des crystaux n'aurons-nous +pas une boule de silex, avec de crystaux de quartz dans ses creux +interieurs." + +The supposed case is this; a calcareous body is to be metamorphosed +into a siliceous nodule, having a cavity within it lined with quartz, +crystals, etc. M. de Carosi means to inform us how this may be done. +Now, as this process requires no other conditions than those that may +be found upon the surface of this earth, the proper way to prove this +hypothetical theory, would be to exhibit such a mineral body produced +by those means. But, even supposing that such a process were to be +exhibited, still it would remain to be explained, how this process, +which requires conditions certainly not be found at the bottom of the +sea, could be accomplished in that place, where the strata of the earth +had been deposited, accumulated, consolidated, and metamorphosed. + +This mineral process, which has been now described, will no doubt revolt +the opinions of many of our chemists as well as naturalists; and I +should not have thought of transcribing it, but as an example of that +inconclusive reasoning which prevails in mineralogical writings upon +this subject. + +But this is not all. We have, upon this occasion, a most remarkable +example of the fallaceous views that may be taken of things; and of the +danger to science when men of sense and observation form suppositions +for the explanation of appearances without that strict conformity with +the principles of natural philosophy which is requited on all occasions. +Both M. de Carosi, and also M. Macquart[40], to whom our author +communicated his ideas and proper specimens, assert, that from their +accurate experience, they find calcedony growing daily, not only in the +solid body of gypsum, etc. while in the mine, but also in the solid +stone when taktn out of the mine, and preserved in their cabinet. + +[Note 40: Vid. Essais de Mineralogie par M. Macquart.] + +What answer can be made to this positive testimony of these gentlemen, +by a person who has not seen any such a thing, and who has not the +opportunity of examining the cases in which those naturalists may have +perhaps been led into some delusion? Were I however to conjecture upon a +subject in which I have not any positive information, I should suppose +that some part of the calcedony, like the _oculus mundi_ when dipped in +water, may be so transparent, while containing some portion of humidity, +that it is not easily distinguishable from the gypsum in which it is +concreted; but that in having the humidity evaporated, by being taken +out of the mine and exposed to the dry air, those portions of calcedony, +which did not before appear, may be perceived by becoming more +opaque[41]. + +[Note 41: From the description given in this treatise, and from the +drawings both of M. de Carosi and M. Macquart, I find a very valuable +inference to be made, so much the more interesting, as I have not found +any example of the like before. This arises from the intimate connection +which is here to be perceived between agate and gypsum. Now, upon this +principle, that the agate-calcedony had been formed by fusion, a truth +which, from the general testimony of minerals, I must presume, it is +plain, that those nodules of gypsum had been in the fluid state of +fusion among those marly strata, and that the gypseous bodies had been +penetrated variously with the siliceous substance of the calcedony. + +The description of those siliceous penetrations of gypsum is followed by +this conclusion: "En voila assez, je crois pour faire voir que le silex +ci-decrit est effectivement une emanation du gypse, et non pas une +matiere heterogene amenee d'autre part et deposee, ou nous la voyons." +In this instance our author had convinced himself that the calcedony +concretions had not been formed, as he and other mineralists had before +supposed, by means of infiltration; he has not, however, substituted +any thing more intelligible in its stead. I do not pretend that we +understand mineral fusion; but only that such mineral fusion is a thing +demonstrable upon a thousand occasions; and that thus is to be explained +the petrification and consolidation of the porous and naturally +incoherent strata of the earth.] + +There is, however, a subject in which I can more freely accuse this +author of being deceived. This naturalist says, that calcareous stones +become silex by a certain chemical operation; and that those flinty +bodies, in being exposed upon the surface of the earth, out of their +natural bed, are again, by a contrary chemical operation, changed from +flint to a calcareous substance. I will give it in his own words, (p. +56.) + +"Cela dit, venons au fait. Tout silex progenere de chaux, detache de son +lieu natal, et expose aux changemens de saisons, s'amollit, recoit de +crevasses, perd sa transparence, devient, enfin, tout-a-fait opaque, le +phlogistique s'en evapore, l'acide en est detache, lave, et de +terre vitrescible, qu'il etoit, il redevient chaux, comme il etoit +auparavant." + +Here is no question with regard to mere opinion, but to matter of fact; +and, in this case, nothing is more evident, than that upon the surface +of this earth, that is, in the examinable parts above the level of the +sea, there is no transition either of calcareous bodies into flint, +nor of flinty bodies into calcareous substance. Calcareous matter is +constantly dissolved by water, when it is exposed to the washing of +that fluid; and it is even dissolved out of the most perfect union or +combination with siliceous substance, and the most solid composition of +an insoluble body, as may be perceived in the decaying of feld-spar. A +superficial view of flints, which have come out of a body of chalk, may +have created such an opinion, which will not either bear the light of +chemical or mineral investigation. The subject of these chalk flints +will be minutely examined in its proper place. + +Our author has carefully examined the subject of flintification; and the +country where he makes his observations would seem to be well disposed +for such a research. He has had great opportunity and inclination to +examine the subject which he writes upon; and he has given a distinct +account of what be has seen. His description of the flintification of +sand-stone is extremely interesting. I will therefore transcribe it, +both as a valuable portion of natural history, and also in order to +contrast this author's opinion, with regard to the means employed by +nature in petrifying bodies, and that which I maintain to be the general +consolidating operation of the globe. It is Section V. _Generation du +Caillou du Silex du Gres, ou Pierre Sablonneuse_. + +"Tout gres est susceptible de cette metamorphose quant au grain et quant +a la couleur; depuis la breccia quartzeuse jusqu'a la pierre a rasoir; +et depuis le gres blanc jusqu'au brun et presque noiratre, tient ou non +tient, dur, ou presque friable, c'est indifferent, toutes ces varietes +donnent du silex, et surtout de la calcedoine, de la cornaline, et des +agathes. Quant au ciment je l'y ai toujours remarque calcaire et faisant +effervescence avec les acides dans les endroits de la pierre qui +n'etoient point encore changes; et jamais je n'ai vu ce changement dans +du gres dont le ciment fut ou quartzeux ou argileux et refractaire. +Ainsi le ciment entre pour quelque chose dans ce changement. + +"Le commencement de cette metamorphose paroit (autant que j'ai pu +l'observer dans mes debris roules) se faire par le ciment, qui dissout +la, ou les agens eurent l'acces libre, rend les grains en quartz +mobiles, les emporte, les mele avec sa masse dense-liquide, les dissout, +meme en partie, et forme, dans cet etat, des veines et de masses +calcedonieuse, carneoliques, ou d'une autre espece de silex, au milieu +du gres peu, ou pas du tout, change. Car autant que je puis voir, ce +n'est pas par couches ou veines qu'elle s'opere, mais par boules et +masses rond-oblongues. Au commencement ces veines et taches sont fort +minces, et le reste du gres n'est point du tout, ou a peine sensiblement +change hormis qu'il gagne, plus de consistence, a proportion du +changement souffert. Mais a mesure que le silex y augmente et se +perfectionne, on y appercoit les degres par lesquels a passe cette +operation. Les nuance du passage d'une pierre a l'autre deviennent plus +visibles, les veines et masses de silex grandissent au point, meme, +qu'il y a jusqu'aux trois quart du gres change en silex clair comme de +l'eau n'ayant que fort peu de grains de sable nageants dans sa masse. +Des morceaux de cette espece sont rares a la verite, mais j'en ai, +cependant, trouve quelques uns. Ordinairement, dans les beaux morceaux, +le silex fait la base, et le sable y est, comme nageant tantot en grains +separes tantot en parties et flocons. Dans les pieces moins belles, le +sable fait la base, et le silex sert a la fois de ciment, et forme aussi +plus ou moins de veines, qui traversent la masse en maintes et maintes +directions. Mais si c'est un gres a gros grains, ou de la breccia, alors +le reste prend la nature silicieuse mele de sable fin, et les gros +grains de quartz restent tels, qu'ils etoient, sans changer. J'ai +deja remarque que cette metamorphose semble s'operer, comme celle des +cailloux d'origine calcaire en forme approchans la spherique, il faut +encore y a jouter, que j'ai lieu de croire, qu'elle se fasse aussi du +dedans en dehors, tout, comme la decomposition se fait du dehors au +dedans. + +"Il arrive dans cette pierre, comme dans toute autre, qu'il se forme +des crystallisations dans les cavites. Lorsqu'elles sont de silex, leur +figure est toujours mamelonnee, mais leur eau ou purete, leur grandeur +et leur couleur n'est pas par tout egale. Il y en a qui sont grands, et +de la plus pure calcedoine, d'autres sont petits et chaque goutte ou +mamelon contient un grain de sable, de facon que cela a l'air d'un gres +crystallise en mamelons ou stalagmitique. D'autres encore sont, de +calcedoine, mais recouverts d'une croute, tantot blanche qui fait +effervescence avec l'acide mineral, et qui est, par consequent, de +nature calcaire; tantot cette croute est bleue foncee nuancee de +bleu-celeste; tantot, enfin, elle est noire, mais toutes les deux +refractaires. Outre ces crystallisations silicieuses, il y en a, quoique +rarement, de quartzeuses, qui ou forment de petites veines de crystal, +ou bien des groupes de crystaux quartzeux, ou qui enfin, enduisent les +mamelons de silex." + +Our author then makes a specification of the different varieties; after +which he continues, p. 69. + +"Apres tout ceci, l'on conviendra j'espere, que notre grais est une +pierre bien singuliere, et surpassant, a bien des egards, le grais, +faussement dit crystallise, de Fontainebleau. La raison de la figure du +grais Francois est fort evidente, c'est le spath calcaire, qui lui +sert de ciment, qui la lui fit prendre; mais qu'est-ce qui opere les +metamorphoses racontees dans notre grais siliceux? Seroit-ce son ciment +calcaire ou marneux par les memes raisons, qui font changer la marne en +silex? La chose est tres-probable, et je n'en saurois pas meme, deviner +d'autre. En ce cas la nature auroit un moyen d'operer par la voie +humide, ce que nous faisons dans nos laboratoires en quelque facon, par +la voie seche, c, a, d, de fondre et liquefier la terre vitrescible, au +moyen des alcalis; secret que nous lui avons deja arrache en partie, en +faisant la liqueur silicieuse." + +"Je n'ose, cependant, decider pas meme hypothetiquement, sur cette +matiere, pour n'avoir pu observer la nature dans ses ateliers, et parce +que je ne possede que des pieces, qui detachees de leur lieu natal, +depuis un tres long-tems, furent exposees aux intemperies des saisons, +ou elles peuvent avoir souffert bien de changemens." + +There cannot be a more fair exposition of facts; and it is only our +author's opinion of this mineral transmutation that I would controvert. +I do not pretend to understand the manner of operating that our author +here supposes nature to take. I only maintain, that here, as every where +in general, the loose and incoherent strata of the globe have been +petrified, that is, consolidated, by means of the fusion of their +substances; and this I think is confirmed from the accurate description +here given of the flintification of sand-stone. Here is described very +distinctly an appearance which is very common or general on those +occasions; this is the parts or particles of stone floating in the fluid +siliceous substance, and there dissolving more or less. + +M. de Carosi describes very systematically the generation of silex, +calcedony, onyx, and quartz, in calcareous earth, marl, gypsum, +sand-stone, and also what he terms _terre glaise, ou de l'Argile_. It is +in this last that we find a perfect analogy with what is so frequent in +this country of Scotland. These are the agates, calcedonies, calcareous +and zeolite nodules, which are found produced in our whin-stone +or subterraneous lavas, that is, the amygdaloides of Crondstedt. +Naturalists explain the formation of those nodular bodies differently. +The Chevalier de Dolomieu supposes these rocks to have been erupted +lavas, originally containing cavities; and that these cavities in the +solid rock had been afterwards filled and crystallised, by means of +infiltration, with the different substances which are found variously +concreted and crystallised within the solid rocks. Our author, on the +contrary, supposes these formed by a species of chemical transmutation +of calcareous and argillaceous earths, which, if not altogether +incomprehensible, is at least not in any degree, so far as I know, a +thing to be understood. + +This is not the place where that subject of these particular rocks, +which is extremely interesting, is to be examined. We shall afterwards +have occasion to treat of that matter at large. It is sufficient here to +observe, that our author finds occasion to generalise the formation of +those petrifactions with the flintifications in calcareous and gypseous +bodies. When, therefore, the formation of any of them shall be +demonstrated, as having taken its origin in the fusion of those +substances, this mode of operation, which is generalised in the +consolidation of strata, will be properly inferred in all the rest. + +Petrifaction is a subject in which mineralogists have perhaps wandered +more widely from the truth than in any other part of natural history; +and the reason is plain. The mineral operations of nature lie in a part +of the globe which is necessarily inaccessible to man, and where the +powers of nature act under very different conditions from those which we +find take place in the only situation where we can live. Naturalists, +therefore, finding in stalactical incrustation a cause for the formation +of stone, in many respects analogous to what is found in the strata of +the earth, and which had come from the mineral region in a consolidated +state, have, without due consideration, attributed to this cause all the +appearances of petrifaction or mineral concretion. It has been one of +the objects of this work to show that this operation of incrustation, +or petrifaction by means of solution, is altogether ineffectual for +producing mineral concretions; and that, even were it capable of forming +those mineral bodies, yet that, in the solid parts of this earth, formed +by a deposit of travelled materials at the bottom of the sea, the +conditions necessary to this incrustating process do not take place. + +Those enlightened naturalists who have of late been employed in +carefully examining the evidences of mineral operations, are often +staggered in finding appearances inconsistent with the received doctrine +of infiltration; they then have recourse to ingenious suppositions, in +order to explain that enigma. In giving examples of this kind. I have in +view both to represent the natural history these mineralists furnish +us with, which is extremely interesting, and also to show the various +shapes in which error will proceed, when ingenious men are obliged to +reason without some necessary principle in their science. We have just +now had an example in Europe; I will next present the reader with one +from Asia. + +M. Patrin, in his _Notice Mineralogique de la Daourie_, (Journal de +Physique, Mars 1791) gives us a very distinct account of what he met +with in that region. Describing the country of Doutchersk upon the river +Argun, in Siberia, he proceeds thus: + +"Ces colines sont formees d'un hornstein gris qui paroit se convertir en +pierre calcaire par l'action des meteores; car tout celui qu'on prend +hors du contact de l'air donne les plus vives etincelles, et ne fait pas +la moindre effervescence avec les acides, meme apres avoir ete calcine; +et l'on observe celui qui est a decouvert, passer, par nuances +insensibles, jusqu'a l'etat de pierre calcaire parfaite de couleur +blanchatre." + +Here M. Patrin has persuaded himself, probably from an imperfect +examination of the subject, that there takes place a mineral +metamorphosis, which certainly is not found in any other part of the +earth, and for which he does not find any particular cause. The natural +effect of the meteors, in other parts of the earth, is to dissolve the +calcareous substance out of bodies exposed to those agents; and the +gradation from the one of those two things to the other, which seems to +be the data on which he had proceeded in forming his conclusion, is not +sufficient to prove the metamorphosis, even were there not so strong a +physical objection to it; for, it is by no means unusual for mineral +bodies to graduate thus from one substance to another. However that be, +this is not the principal object of the example[42]. + +[Note 42: Here we have well informed naturalists reasoning with all the +light of our present mineralogy, and maintaining, on the one hand, that +gypsum is transformed into calcedony, by the operation of the meteors, +or some such cause; and, on the other, that a siliceous substance is by +the same means converted into lime-stone. What should we now conclude +from this?--That calcareous and siliceous substances were mutually +convertible. But then this is only in certain districts of Poland and +Siberia. Every where, indeed, we find strange mixtures of calcareous and +siliceous bodies; but neither mineralists nor chemists have, from these +examples, ventured to affirm a metamorphosis, which might have spared +them much difficulty in explaining those appearances. + +This is a subject that may be taken in very different lights. In one +view, no doubt, there would appear to be absurdity in the doctrine of +metamorphosis, as there is now a days acknowledged to be in that of +_lusus naturae_; and those reasoning mineralists might thus, in the +opinion of some philosophers, expose their theory to contempt and +ridicule. This is not the light in which I view the subject. I give +those gentlemen credit for diligently observing nature; and I applaud +them for having the merit to reason for themselves, which would seem to +be the case with few of the many naturalists who now speak and write +upon the subject. + +Let us now draw an inference, with regard to this, in judging of the +different theories. Either the received system concerning mineral +operations is just, in which case those gentlemen, who employ a secret +metamorphosis, may be to blame in laying it aside; or it is erroneous +and deficient; and, in that case, they have the merit of distinguishing +the error or deficiency of the prevailing system. How far they have seen +the system of nature, in those examples which they have described, +is another question. In the mean time, I am to avail myself of the +testimony of those gentlemen of observation, by which the insufficiency +at least of the received mineral system is acknowledged.] + +After speculating upon the effect of the ancient ocean upon the +mountains of that country, he proceeds as follows: + +"Je laisse ces conjectures pour remarquer un fait singulier: la colline, +qui est au nord de l'eglise de la fonderie, a son arrete composee de ce +hornstein qui se decompose en pierre calcaire; mais ici, les parties, +qui sont ainsi decomposees, offrent une substance calcedonieuse +disposees par zones concentriques, comme on l'observe dans les agates +d'oberstein; mais ce ne sont point ici des corps parasites formes par +infiltration dans des cavites pre-existantes comme les agates; on voit +que ce sont les parties constituantes de la roche qui, _par un +travail interne_, et par une sorte de crystallisation, out pris cette +disposition reguliere (que ce mot de _crystallisation_ ne revolte point, +j'appelle ainsi toute tendance a prendre une forme constante, polyedre +ou non polyedre.) Les couches les plus voisine du centre sont nettes et +distinctes; peu-a-peu elles le sont moins, et enfin elles s'evanouissent +et se confondent avec le fond de la roche. Chaque assemblage de ces +zones a une forme ronde ou ovale plus ou moins reguliere de sept a huit +pouces de diametre. + +"Cela ressemble en grand a ce qu'on observe dans les pierres oeillees, +et la cause est vraisemblablement la meme. Je le repete, je regarde +cette disposition reguliere comme une veritable cristallisation, qui +peut s'operer et qui s'opere en effet dans l'interieur des corp les plus +solide, tant qu'ils sont fournis a l'action des agens de la nature. + +"Tous ceux qui visitent l'interieur de la terre savent que les roches +memes le plus compactes y sont intimement penetrees d'humidite, et ce +fluide n'est certainement pas l'eau pure; c'est l'agent qui opere toutes +les agregations, toutes les cristallisations, tous les travaux de la +nature dans le regne mineral. On peut donc aisement concevoir qu'a la +faveur de ce fluide, il regne, dans les parties les plus intimes des +corps souterrains, une circulation qui fait continuellement changer de +place aux elemens de la matiere, jusqu'a ce que reunis par la force des +affinites, les corpuscules similaires prennent la forme que la nature +leur a assignee." + +Those nodular bodies or figured parts which are here inclosed in the +rock, are evidently what may be called calcedony agates. M. Patrin is +persuaded, from the examination of them, that they had not been formed +in the manner of German agates, which he supposes is by mean of +infiltration; and he has endeavoured to conceive another manner of +operating, still however by means of water, which I suppose, according +to this hypothesis, is to dissolve substances in one part, and deposits +them in another, There must certainly be some great _desideratum_ in +that mineral philosophy which is obliged to have recourse to such +violent suppositions. First, water is not an universal solvent, as it +would require to be, upon this supposition; secondly, were water allowed +to be an universal menstruum, here is to be established a circulation +that does not naturally arise from the mixture of water and earth; and, +lastly, were this circulation to be allowed, it would not explain the +variety which is found in the consolidation and concretion of mineral +bodies. + +So long, therefore, as we are to explain natural appearances by +reasoning from known principles, and not by ascribing those effects to +preternatural causes, we cannot allow of this regular operation which +M. Patrin alleges to be acting in the interior parts of the most solid +bodies. This is indeed evident, that there has been a cause operating +in the internal parts of the most solid bodies, a cause by which the +elements, or constituent parts of those solid bodies, have been moved +and regularly disposed, as this author very well observes must have been +the case in our agates or eyed stones; but to ascribe to water this +effect, or to employ either an ineffectual or an unknown cause, is not +to reason philosophically with regard to the history of nature; it is to +reason phantastically, and to imagine fable. + +M. Monnet has imagined a petrifying power in water very different +from any that has hitherto been conceived, I believe, by natural +philosophers, and I also believe, altogether inconsistent with +experience or matter of fact; but as it is not without good reason that +this naturalist has been induced to look out for a petrifying cause +different from any hitherto supposed, and as he has endeavoured very +properly to refute the systems of petrification hitherto received, +I would beg leave to transcribe his reasoning upon the subject in +corroboration of the present theory of consolidation by the means of +fusion. + +It is upon occasion of describing one of the species of alpine stone +or schistus which contains quartzy particles. _Nouveau voyage +mineralogique, etc._ Journal de Physique Aoust 1784. + +"Il y a loin de cette pierre, que je regarde comme une variete de roches +ardoisees, aux veritable ardoises. La composition de toutes ces pierres +est due aux terres quartzeuses et argileuses, et a la terre talqueuse, +que je demontrerai un jour etre une espece particuliere et distincte des +autres, qui constitue les bonnes ardoises, et fait, ainsi que le quartz, +qu'elles resistent aux injures de l'air, sans s'effleurir, comme je +ferai voir que cette terre, qu'on designera sous la denomination de +terre talqueuse, si l'on veut, resiste au grand feu sans se fondre. Les +differences de toutes ces pierres, quoique composees des memes matieres, +mais dans des proportions differentes, sont frappantes, et pourroient +faire croire qu'elles n'appartiennent pas a ce genre. Mais qui ne voit +ici que toutes ces differences, ou ces varietes, ne sont dues qu'aux +modifications de la matiere premiere, qu'elle a eprouvees, soit en se +melant avec des matieres heterogenes, prevenantes du debris des etres +qui ont existe, comme l'argile, par exemple, qui, de l'aveu de presque +tous les naturalistes, est le produit de l'organization des plantes, ou +soit en se melant avec de la matiere deja solidifiee depuis long-temps? +Or nous ne craignons pas de dire, ce que nous avons dit plusieurs fois +quand l'occasion s'en est presentee, que cette matiere unique, que +se modifie selon les occasions et les circonstances, et qui prend +un caractere analogue au matieres qu'elle rencontre, est l'eau, que +beaucoup de naturalistes cherchent vainement ailleurs. Ils ne peuvent +comprendre, malgre les exemples frappans qui pourroient les porter a +adopter cette opinion, que ce fluide general soit l'element des corps +solides du regne mineral, comme il est de ceux du regne vegetal et du +regne animal. L'on cherche serieusement, par des experiences chimiques, +a decouvrir si l'eau est susceptible de se convertir en terre comme +si la nature n'avoit pas d'autre moyen que nous de la faire passer de +l'etat fluide a l'etat solide. Voyez le spath calcaire et le quartz +transparens; est il a presumer qu'ils ne sont que le resultat du depot +des matieres terreuses fait par les eaux? Mais, dans ce ca-la encore, +il faut supposer que l'eau qui est restee entre ces partie s'est +solidifiee; car, qu'est-elle donc devenue, et quel est donc le lien qui +a uni ces parties et leur a fait prendre une forme reguliere? Il est +vrai qu'on nous parle d'un suc lapidifique; mais c'est-la un etre de +raison, dont il seroit bien plus difficile d'etablir l'existence, que de +croire a la solidification de l'eau. On nous donne cependant comme un +principe certain que l'eau charie d'un lieu a un autre les matieres +qu'il a dissoutes, et qu'elle les depose a la maniere des sels. Mais +c'est supposer une chose dementie par l'experience; savoir, que l'eau +ait la propriete de dissoudre les matieres terreuses, telles que la +quartzeuse. A la verite, M. Auchard de Berlin y joint de l'air fixe; +mais cet air fixe ne sauroit tenir en dissolution un atome de quartz +dans l'eau; et quelle qu'ait ete l'exactitude de ceux qui ont repete +les experiences de M. Auchard, on n'a pu reussir a imiter la nature, +c'est-a-dire, a former des cristaux quartzeux, comme il a annonce. Que +l'eau ait la faculte de tenir en dissolution quelques petites parties +de terre calcaire, au moyen de cet air fixe, il n'en faut pas conclure +qu'elle puisse former de cette maniere tous les cristaux calcaires, sans +que l'eau elle-meme y concoure pour sa part; car ce seroit conclure +quelque fois que la partie seroit egale au tout. Voyez ces geodes +calcaire et argileuses, qui renferment des cristaux nombreux de quartz +ou de spath calcaire; ne sont ils que le resultat du depot de l'eau +qui y a ete renfermee, ou que la cristallization pure et simple des +molecules que vous supposez avoir ete tenues en dissolution par cette +eau? Il naitroit de cette opinion une foule d'objections qu'il seroit +impossible de resoudre. Cependant M. Guettard, dans la mineralogie du +Dauphine, qui vient de paroitre, ouvrage tres-estimable a beaucoup +d'egards, explique, selon cette maniere de penser, la formation de +cristallizations quartzeuses qu'on trouve dans certaines geodes de +cette province, et celle des mines de cristal des hautes montagnes. En +supposant meme comme vraie l'explication qu'il en donne, on trouveroit +en cela un des plus grands probleme, et des plus difficiles a resoudre +qu'il y ait en mineralogie; car d'abord il faudroit expliquer comment un +si petite quantite d'eau que celle qui a ete renfermee dans les geodes, +et celle qui est parvenue dans les fentes des rochers, ont pu fournir +un si grande quantite de matiere que celle qui constitue ces +cristallisations, et ce qui n'est pas le moins difficile a concevoir, +comment l'eau a pu charrier cette matiere a travers tant de matieres +differentes, et la conserver precisement pour cette destination; +comment, par exemple, l'eau est venue deposer de la terre quartzeuse +dans les masses enormes de pierres calcaires, qui forment la cote qui +domine le village de Champigny, a quatre lieues de Paris, au dela de +Saint-maur; car s'il nous faut citer un exemple frappant de cette +singularite, et a portee d'etre vue des naturalistes qui sont dans la +capitale, je ne puis mieux faire que de citer cette cote, une des plus +curieuses de la France, et que je me propose de fair connoitre en detail +dans la troisieme partie de la mineralogie de la France. On verra, +dis-je, dans cette bonne pierre a chaux, et une de plus pure des +environs de Paris, de tres-abondantes cristallisations de quartz +transparent, et quelque fois de belle eau, que les ouvriers sont forces +de separer de la partie calcaire, a laquelle elles adherent fortement. +Mais c'est trop nous arreter a combattre une opinion qui doit son +origine aux premieres idees qu'ont eues les premiers observateurs en +mineralogie, qui se detruira d'elle meme comme tant d'autres dont il +nous reste a peine le souvenir." + +We find here an accurate naturalist, and a diligent observer, who, in +conformity with what my sentiments are upon the subject, thinks it +impossible that the crystallizations in close cavities, and concretions +of different solid substances within each other, which so frequently +occur in the mineral regions, could have been produced, by means of +solution and crystallization, from a fluid vehicle. But what has he +now substituted in place of this solution, in order to explain +appearances?--a mere supposition, viz. that nature may have the power +of converting water, in those secret places, into some other thing; or +rather that the substance of water is here converted into every other +thing; for, though he has only mentioned quartz and calcareous spar, +what mineral substance is there that may not be found in those close +cavities? They are actually almost all, not even excepting gold; for, +small grains of gold are inclosed within the cavities of a porous stone, +in the Siberian mine. Now, for what purpose should nature, (to the power +of which we are not to set a limit) have such an object in view as +to convert water into every thing, unless it were to confound human +understanding? For, so far as human experience has been as yet able to +reach, there would appear to be certain elementary substances; and among +these is water, or the principles of that fluid[43]. But because water +is so generally found in bodies, and so necessarily in most of the +operations of this world, why convert it into every other thing? Surely, +for no better reason than that there has not occurred to this mineralist +any other way of explaining certain natural appearances which aqueous +solution could not produce. Here is no dispute about a matter of fact; +it is on all hands allowed, that in certain cavities, inaccessible to +any thing but heat and cold, we find mineral concretions, which contain +no water, and which, according to the known operations of nature, water +could not have produced; must we therefore have recourse to water acting +according to no known principle, that is to say, are we to explain +nature by a preternatural cause? + +[Note 43: Water is now considered by men of science, as a compound +substance; this doctrine, which seems to follow so necessarily from the +experiments of the French philosophers, must be tried by the growing +light of chemical science. In the oxygenating operation of inflammable +and combustible bodies when burning, those ingenious chemists overlooked +the operation of _phlogistic matter_, which has no weight, and +which escapes on that occasion, as I have had occasion to show in a +dissertation upon phlogiston, and in the Philosophy of Light, Heat, +and Fire. How far this view, which I have given of those interesting +experiments, may lead to the explanation of other collateral phenomena, +such as that of the water produced, I will not pretend to conjecture. +One thing is evident, that if the weight of the water, procured in +burning inflammable and vital air, be equal to that of those two gasses, +we would then have reason to conclude, either that water were a compound +substance, or that vital air, and inflammable vapour were compounds of +water and the matter of light, or solar substance.] + +I dare say that this is not the view that M. Monnet takes of the +subject, when he thinks to explain to himself the concretion of +those different substances by means of water; but, according to my +apprehension of the matter, his theory, when sifted to the bottom, will +bear no other construction; and, unless he shall consider water like the +matter of heat, as capable of producing the fluidity of fusion, and of +being also again abstracted from the fluid, by pervading the most solid +body, which would then be a substance different from water, he must +employ this aqueous substance as a menstruum or solvent for solid +bodies, in the same manner as has been done by those naturalists whom +he he justly censure, and conform to those erroneous ideas which first +observations, or inaccurate knowledge of minerals, may have suggested to +former naturalists. + +It is the dissolution and concretion of siliceous substance, no +doubt, that gives such difficulty to our naturalists in explaining +petrifaction: they have, however, something apparently in their favour, +which it may be proper now to mention. + +In the _first_ place, although siliceous substance is not soluble, so +far as we know, by simple water, it is soluble by means of alkaline +substance; consequently, it is possible that it may be dissolved in the +earth. + +_Secondly_, The water of Giezer in Iceland, actually petrifies bodies +which are alternately imbibed with that hot water and exposed to the +air. This water, therefore, not only contains siliceous substance in a +dissolved state, but deposits this again, either by means of cooling, +or being aerated, or of evaporating. Consequently, without knowing the +principle upon which it proceeds, we here perceive a natural operation +by which siliceous petrifaction may be performed. + +_Lastly_, We have another principle for the dissolution of siliceous +substance. This is the fluor acid which volatilises the siliceous +substance. This, however, requires certain conditions, which cannot be +found as a general cause in the mineral regions. + +Thus we would seem to have every thing necessary for explaining the +concretion and crystallization of siliceous bodies, provided we could +find the proper conditions requisite for that operation; for whether it +shall be by means of acid or alkaline substances that siliceous matter +is to be dissolved, volatilised, and transported from one place to +another, it is necessary that those dissolving substances should be +present upon those occasions. Nor is it sufficient only to dissolve the +siliceous substance which is to be transported; the necessary conditions +for the concretion again of the dissolved substances, whatever these may +be, are also absolutely required for this operation. Now, though those +requisite conditions may be, upon many occasions, allowed in the earth, +it is not according to the theory of our modern naturalists, who explain +petrifaction upon the principles of simple infiltration of water, +that any advantage can be taken of those conditions; nor are natural +appearances to be explained without employing more complicated chemical +agents in the mineral regions. + +To this subject of the petrifactions of Giezier, I may now add the +information which we have received in consequence of a new voyage from +this country to Iceland. + +When Sir Joseph Banks returned from his expedition to Iceland, he landed +at this place; and, having brought specimens of the petrifications of +Giezer, Dr Black and I first discovered that these were of a siliceous +substance. I have always conjectured that the water of Giezer must be +impregnated with flinty matter by means of an alkaline substance, and +so expressed my opinion in the Theory of the Earth published in the +Transactions of the Edinburgh Royal Society. We have therefore been very +desirous of procuring some of that water, in order to have it analysed. + +An opportunity favourable to our views has occurred this summer. Mr +Stanley set out from this place with the same purpose of examining +Iceland. He was so good as to ask of Dr Black and I what inquiries we +would incline that he should make. We have now, by the favour of this +gentleman, obtained specimens of the petrifactions of Giezer; and, what +is still more interesting, we have procured some of the water of those +petrifying boiling springs. + +It appears from these specimens, that the boiling water which is ejected +from those aqueous volcanoes, if we may use the expression, is endued +with the quality of forming two different species of petrifaction or +incrustation; for, besides the siliceous bodies, of which we had before +received specimens, the same stream of water incrustates its channel +with a calcareous substance. All the specimens which I have seen consist +of incrustation, some purely siliceous, some calcareous, and others +mixed of those two, more or less. + +Dr Black has been analysing the water; and he finds in it siliceous +matter dissolved by an alkaline substance, in the manner of liquor +silicum[44]. My conjecture has thus been verified. + +[Note 44: See Trans. of the Edin. Royal Society.] + +It must not be alleged that nature may operate in the mineral regions, +as she does here upon the surface in the case of Giezer. Such an +argument as this, however sound it may be in general, will not apply to +the subject of which we treat at present. There is no question about +the limiting the powers of nature; we are only considering nature as +operating in a certain determined manner, viz. by water acting simply +upon the loose materials of the land deposited at the bottom of the +sea, and accumulated in regular strata, one upon another, to the most +enormous depth or thickness. This is the situation and condition of +things in which nature is to operate; and we are to find the means of +consolidating those strata, and concreting every species of substance +in almost every possible composition, according to some known physical +principle. Here is an operation which is limited; for, we must reason +strictly, according to the laws of nature, in the case which we have +under consideration; and we cannot suppose nature as ever transgressing +those laws. + +It is acknowledged, that, by means sometimes of an aeriform, sometimes +of an alkaline, perhaps also of an acid substance, calcareous matter is +dissolved in the earth, and certain metallic substances, such as lead +and iron. This solution also, upon particular occasions, (where the +proper conditions for separating the solvent from the dissolved +substance exist), forms certain concretions; these are sometimes a mere +incrustation, as in the case of the siliceous incrustation of Giezer, +sometimes again in a crystallised or sparry form, as in the case of +stalactical concretions. But here is no question of those cases where +the proper conditions may be found; first, of dissolving the substance +which is afterwards to be concreted; secondly, of separating the +menstruum from the dissolved substance; and, lastly, of removing the +fluid deprived of its solution, and of supplying a new solution in its +room; the question is, how far those concretions are formed where those +conditions do not take place. Now, this last case is that of almost all +mineral concretions. + +It must not be here alleged that certain concretions have been found in +mines posterior to these having been worked by man; consequently, that +those concretions have been formed by nothing but the infiltration of +water. In those cases, where such concretions are truly found, I am +persuaded that all the conditions proper to that operation will also +be found; and it is only, I believe, in those cases where such proper +conditions may be found, that this aqueous concretion ever appears. Now, +if we shall except calcareous stalactite, and the bog ore of iron, How +seldom is it that any appearance of those aqueous mineral concretion +ever is found? Those very few cases in which they are found, afford the +strongest proof against these being operations general to the globe, or +proper mineral concretions; because it is only where all the necessary +conditions conspire in each contributing its part, that the effect is +accomplished; and this is a thing which cannot possibly take place in +the aquiform strata below the surface of the sea. But, without attending +to this clear distinction of things perfectly different, naturalists are +apt to see false analogies, and thus in generalising to form the most +erroneous theories. + +I shall now give an example of this fallaceous manner of reasoning; it +is in the case of certain mineral appearances which are erroneously +considered as stalactical concretions. + +The only true stalactical bodies are of a calcareous substance; they are +formed by water containing this substance in a dissolved state; and the +principles upon which this particular concretion is formed are well +known. It is therefore easy to compare other concretions, which may have +some superficial resemblance to these stalactical bodies, in order to +see if they have proceeded upon the same principle of concretion from +a dissolved state, or by water depositing its dissolved substance in a +similar manner. + +There are two different mineral substances which give appearances of +this sort. These are certain concretions of calcedony, and also of +iron-ore, which are thought to have such resemblance to stalactical +concretions as, by some superficial observers, to be reckoned of the +same kind. It is now proposed to show that those conclusions are not +well founded; and that, in this case of calcedony and iron-ore, it could +not be upon the principle of stalactical concretion that the bodies now +in question had their forms. + +The principle upon which calcareous substance is dissolved in water, and +made to concrete by the evaporation of the acid substance, or fixed +air by which it had been dissolved, is too well known to require any +explanation in this place; we are only to consider the sensible effects +of those operations of which we know so well the proper conditions. + +There are just two distinct views under which we may consider all +stalactical concretions formed; these are the incrustation of +the calcareous substance concreting upon a foreign body, and the +incrustation of the same substance upon itself. By the first any manner +of shape may be formed, provided there be a solid body, upon the surface +of which the calcareous solution is made to pass. By the second, again, +we have various forms; but we know the principles upon which they had +been made. These are the shape and motions of the fluid which gives the +calcareous concretion. Now, these principles are always to be perceived, +more or less, in all the bizarre or fantastical, as well as regular +shapes which are produced by stalactical concretions. At present, we +shall confine our views to one particular shape, which is simple, +regular, and perfectly understood wherever it is formed. + +Drops of water falling from a roof, and forming stalactite, produce +first tubular bodies, and then gradually consolidate and increase those +pendulous bodies by incrustation. These appearances are thought to be +observed in the calcedony and ferruginous concretions, which has led +some mineralists to conclude, that those concretions had been formed +in the same manner, by means of water. We are now to show that these +mineral appearances are not analogous to stalactites in their formation, +and that they have evidently been formed in a different manner. + +It must be evident, that, in the formation of those pendulous bodies, +each distinct stalactite must be formed by a separate drop of water; +consequently, that no more stalactites can be formed in a given space, +than there could have subsisted separate drops of water. Now, a drop of +water is a very determined thing; and thus we have a principle by which +to judge of those mistaken appearances. + +Let us suppose the gut of water to be but one eighth of an inch, +although it is a great deal more, we should have no stalactites formed +nearer to each other than that measure of space. But those mineral +concretions, which are supposed to be stalactical, are contained in half +that space, or are nearer to each other than the tenth or twentieth of +an inch. I have them like needles, and in every degree of proximity or +contiguity, at the same time that they are perfectly solid. Therefore, +it is plainly impossible that they could have been formed upon this +principle of calcareous stalactite. But, it is only by this false +resemblance, that any argument can be formed for the concretion of those +bodies from an aqueous solution; in every other respect they are true +mineral concretions; and, that these have had a very different origin, +has been already the subject of investigation, and will be more +particularly examined in the course of this work. + +The term _infiltration_, which has been much employed for explaining +mineral appearances, is too vague, imperfect, or unexplicit, for +science, whether as the means of knowing nature, or the subject of +confutation. This is not the case with that of stalactite; here is +a term that implies a certain natural operation, or a most distinct +process for attaining a certain end; and we know the principles upon +which it proceeds, as well as the several steps that may be traced in +the general result. It is an operation which has not only been analysed +to its principles; it is also a process which is performed by man, +proceeding on his acquired knowledge. Now, were this operation common to +the mineral regions, as it is proper to the surface of this earth; we +could not remain in any degree of suspense with regard to the origin of +those mineral bodies; for, having the true clue of knowledge, we should +be able to unravel the most intricate and mysterious appearance. But, so +far from this being the case, the more we come to inquire into nature, +and employ this principle, the less we find it applicable, and the more +involved in darkness is our science. + +The places where these false appearances of stalactite are found, are +precisely those in which, from the nature of things, all possibility for +such an operation is excluded. For, How can this take place within a +closs cavity in the mineral regions? The term _vegetation_ may as well +be employed for the explanation of those appearances: But what would +now be said of such an explication? It is high time that science were +properly applied to the natural history of this earth, and mineralists +not allowed to impose upon themselves with false reasoning, or to please +themselves with the vain attempt of explaining visible effects by +unknown causes. + +Such various inconsistent opinions, respecting petrifaction or mineral +concretion, as I have now exposed, opinions that are not founded on any +sound physical principle, authorise me to conclude that they are all +erroneous. If this be admitted, it will follow that we have no proof +of any proper mineral concretion except that which had proceeded by +congelation from the fluid state of fusion. This has been the doctrine +which I have held out in my Theory of the Earth; and this will be more +and more confirmed as we come to examine particular mineral appearances. + + + +CHAP. VIII. + +The Nature of Mineral Coal, and the Formation of Bituminous Strata, +investigated. + + +SECT. I.--Purpose of this Inquiry. + +In the first chapter, I have given a perfect mark by which to judge, +of every consolidated stratum, how far that had been the operation or +effect of water alone, or if it had been that of heat and fusion. This +is the particular veins or divisions of the consolidated stratum, +arising from the contraction of the mass, distended by heat, and +contracted in cooling. It is not an argument of greater or lesser +probability; it is a physical demonstration; but, so far as I see, it +would appear to be for most mineralists an unintelligible proposition. +Time, however, will open the eyes of men; science will some day find +admittance into the cabinet of the curious. I will therefore now give +another proof,--not of the consolidation of mineral bodies by means +of fusion, for there is no mineral body in which that proof is not +found,--but of the inconsistency of aqueous infiltration with the +appearances of bodies, where not only fusion had been employed for the +consolidation, but where the application of heat is necessary, and along +with it the circumstances proper for _distillation_. + +Short-sighted naturalists see springs of water issuing from the earth, +one forming calcareous incrustations, the other depositing bituminous +substances. Here is enough for them to make the theory of a world; on +the one hand, solid marble is explained, on the other, solid coal. +Ignorance suspects not error; their first step is to reason upon a false +principle;--no matter, were they only to reason far enough, they would +soon find their error by the absurdity into which it lands them. The +misfortune is, they reason no farther; they have explained mineralogy +by infiltration; and they content themselves with viewing the beautiful +specimens in their cabinet, the supposed product of solution and +crystalization. How shall we inform such observators; How reason with +those who attend not to an argument! + +As naturalists have explained all mineral concretions from aqueous or +other solution, and attributed to infiltration the formation of those +stony bodies in which there are marks of their original composition, +so have they explained to themselves, I suppose, the origin of those +bituminous bodies which are found among the strata of the earth. In the +case of stony substances, I have shown how unfounded all their theories +are for the production of those concretions, crystallizations, and +consolidated bodies. I am here to examine the subject of inflammable and +combustible bodies, which I believe have been little considered by those +theorists who suppose mineral bodies consolidated by infiltration. It is +here that we shall find an infinite difference between the aqueous and +igneous theories; for, we shall find it impossible to explain by the one +certain operations which must have necessarily required the great agent +generally employed in the other. + +The subject of this chapter is a touch-stone for every theory of the +earth. In every quarter of this globe, perhaps in every extensive +country, bituminous strata are to be found; they are alternated with +those which are called aquiform, or which had been evidently formed by +subsidence of certain moved materials at the bottom of the sea; so far, +therefore, all those strata have had the same origin. In this point +I think I may assert, that all the different theories at present are +agreed; and it is only concerning certain transformations of those +strata, since their original collection, that have been ascribed to +different causes. + +Of these transformations, which the strata must have undergone, there +are two kinds; one in relation to change of place and position; the +other in relation to solidity or consistence. It is only the last of +those two changes which is here to be the subject of consideration; +because, with regard to the first, there is nothing peculiar in these +bituminous strata to throw any light, in that respect, upon the others. +This is not the case with regard to the transformation in their chemical +character and consistence; bituminous bodies may not be affected by +chemical agents, such as fire and water, in the same manner as the +argillaceous, siliceous, micaceous, and such other strata that are +alternated with the bituminous; and thus we may find the means for +investigating the nature of that agent by which those strata in general +have been transformed in their substance; or we may find means for the +detecting of false theories which may have been formed with regard +to those operations in which the original deposits of water had been +changed. + +We have had but two theories, with regard to the transformation of +those bodies which have had a known origin, or to the change of their +substance and consistence; the one of these which I have given is that +of heat or fusion; the other, which I wish to be compared with mine, +is that of water and infiltration. It is by this last that all authors +hitherto, in one shape or another, have endeavoured to explain the +changes that those strata must have undergone since the time of their +first formation at the bottom of the sea. They indiscriminately apply +the doctrine of infiltration to those strata of mineral coal as to any +other; they say that bituminous matter is infiltrated with the water, +impregnates certain strata of earth with bituminous matter, and thus +converts them into mineral coal, and bituminous strata. This is not +reasoning physically, or by the inductive method of proceeding upon +matter of fact; it is reasoning fantastically, or by making gratuitous +supposition founded merely on imagination. It was thus that natural +philosophers reasoned before the age of science; the wonder now is, +how men of science, in the present enlightened age, should suffer such +language of ignorance and credulity to pass uncensured. + +The subject which I am now to treat of consists of peculiar strata of +the earth, bodies which we may investigate through all the stages of +their change, which is extreme; for, from vegetable bodies produced upon +the habitable earth, they are now become a mineral body, and the most +perfect coal,--a thing extremely different from what it had been, and +a thing which cannot be supposed to have been accomplished by the +operation of water alone, or any other agent in nature with which we +are acquainted, except the action of fire or heat. It is therefore +impossible for a philosopher, reasoning upon actual physical principles, +not to acknowledge in this a complete proof of the theory which has been +given, and a complete refutation of that aqueous operation which has +been so inconsiderately supposed as consolidating the strata of the +earth, and forming the various mineral concretions which are found in +that great body. + +To see this, it will be sufficient to trace the progress of vegetable +and animal substances, (bodies which had certainly lived by means of a +former earth), to this changed state in which they have become perfect +mineral bodies, and constitute a part of the present earth. For, as +these changes are perfectly explained by the one theory, and absolutely +inconsistent with the other, there arises from this a conviction that +must be irresistible to a person who can give proper attention to a +chain of reasoning from effect to cause. + +But if we thus succeed to illustrate the theory of the earth by the +natural history of those particular strata, we have but one step farther +to make in order to bring all the other parts of the earth, whether +stratified or not, into the most perfect consistence with the theory; +now this step, it will be most easy to make; and I shall now mention +it, that so the reader may keep it in his view: Pyrites is a +sulphureo-metallic substance, which cannot be produced by means of +water, a substance which the influences of the atmosphere decomposes or +separates into its elements, and which even our imperfect art may +be considered as able to produce, by means of fusion in our fires. +Therefore, the finding of this creature of fire intimately connected +with those consolidated strata of mineral coal, adds the greatest +confirmation, were it necessary, to the doctrine of those mineral bodies +having been consolidated by fusion. This confirmation, however, is +not necessary, and it is not the only thing which I am at present to +illustrate in that doctrine. What I have now in view is, to homologate +the origin of those coal strata, with the production of every other +mineral substance, by heat or fusion; and this is what the intimate +connection of pyrites with those strata will certainly accomplish. This +will be done in the following manner: + +Pyrites is not only found in great masses along with the coal strata; it +is contained in the veins which traverse those strata, and in the minute +ramifications of those veins, which are occasioned by the contraction of +the mass, and generally divide it into small cubical pieces; but besides +that extrinsic connection, (as it may be called,) with the stratum of +coal, pyrites is found intimately connected with that solid body, in +being mixed with its substance. If, therefore, it were proved, that +either the one or other of those two substances had been consolidated by +fusion, the other must be acknowledged as having had the same origin; +but now I am to prove, from the natural history of mineral coal, that +pyrites had been there formed by fusion; and then, by means of the +known origin of that sulphureo-metallic substance, we shall extend our +knowledge to the origin of every other mineral body. + +The process of this argument is as follows: Every mineral body, I +believe, without exception, will be found so intimately connected with +pyrites, that these two things must be concluded as having been together +in a fluid state, and that, whatever may have been the cause of fluidity +in the one, this must have also caused the fluidity in the other; +consequently, whatever shall be proved with regard to the mineral +operations of pyrites, must be considered as proved of every other +mineral substance. But, from the connection of pyrites with mineral +coal, it is to be proved that the origin of this metallic body had been +fusion; and then it will appear, that all other mineral bodies must have +been more or less in fusion, or that they must have been consolidated +by means of heat, and not by any manner of solution or aqueous +infiltration. I therefore now proceed to take a view of the natural +history of coal strata,--a subject which mineralogists seem not inclined +to engage with, although the most ample data are to be found for that +investigation. + + +SECT. II.--Natural History of Coal Strata, and Theory of this +Geological Operation. + +Fossil coal is the species of stratum best understood with regard to its +accidents, as being much sought after; at least, this is the case in +many parts of Britain, where it supplies the place of wood for burning. +This fossil body has the most distinguished character; for, being +inflammable or combustible in its nature, there is no other species of +stratum that may be confounded with it. + +But, though coal be thus the most distinguishable mineral, and that +which is best understood in the science of mining, it is perhaps the +most difficult to be treated of in the science of mineralogy; for, +not having properly any distinguishable parts, we have nothing in the +natural constitution of this body, as we have in most other strata, to +lead us to the knowledge of its original state or first formation. + +The varieties of coal are distinguished by their different manner of +burning; but, from appearances of this kind, no perfect judgement can be +formed with regard to the specific manner in which those strata had been +made; although, from chemical principles, some conclusion may be drawn +concerning certain changes which they have undergone since they had been +formed. + +Thus we have one species of coal which is extremely fusible, abounds +with oil, and consequently is inflammable; we have another species again +which is perfectly fixed and infusible in the fire; therefore, we may +conclude upon principle, that, however, both those coals must have +undergone the operation of heat and fusion, in bringing them to their +present state, it is only the last that has become so much evaporated as +to become perfectly fixed, or so perfectly distilled, as to have been +reduced to a caput mortuum. + +The argument here employed is founded upon this fact; that, from the +fusible species of coal, a caput mortuum may be formed by distillation, +and that this chemical production has every essential quality, or every +peculiar property, of the fixed and infusible species; although, from +the circumstances of our operation, this caput mortuum may not have +precisely the exterior appearance of the natural coal. But, we have +reason to believe, it is not in the nature of things to change the +infusible species, so as to make it fusible or oily. Now, that this body +was not formed originally in its present state, must appear from this, +that the stratum here considered is perfectly solid; but, without +fusion, this could not have been attained; and the coal is now supposed +to be infusible. Consequently, this fixed substance, which is now, +properly speaking, a perfect coal, had been originally an oily +bituminous or fusible substance. It is now a fixed substance, and an +infusible coal; therefore, it must have been by means of heat and +distillation that it had been changed, from the original state in which +this stratum had been formed. + +We have thus, in the examination of coal strata upon chemical +principles, received a certain lesson in geology, although this does not +form a proper distinction by which to specify those strata in general, +or explain the variety of that mineral. For, in this manner, we +could only distinguish properly two species of those strata; the one +bituminous or inflammable; the other proper coal, burning without smoke +or flame. Thus it will appear that, as this quality of being perfectly +charred is not originally in the constitution of the stratum, but an +accident to which some strata of every species may have been subjected, +we could not class them by this property without confounding together +strata which had differences in their composition or formation. +Therefore, we are led to inquire after some other distinction, which may +be general to strata of fossil coal, independent of those changes which +this substance may have undergone after it had been formed in a stratum. + +Perfect mineral coal being a body of undistinguishable parts, it is only +in its resolution that we may analyse it, and this is done by burning. +Thus, in analysing coal by burning, we have, in the ashes alone, that by +which one species of coal may be distinguished from another; and, if we +should consider pure coal as having no ashes of itself, we should then, +in the weight of its ashes, have a measure of the purity of the coal, +this being inversely as the quantity of the ashes. Now, though this be +not accurately true, as the purest coal must have some ashes proper to +itself, yet, as this is a small matter compared with the quantity of +earthy matter that may be left in burning some species of coal, this +method of analysis may be considered as not far removed from the truth. + +But, in distinguishing fossil coal by this species of chemical analysis, +not only is there to be found a perfect or indefinite gradation from a +body which is perfectly combustible to one that is hardly combustible in +any sensible degree, we should also fall into an inconveniency similar +to that already mentioned, of confounding two things extremely different +in their nature, a bituminous body, and a perfect charcoal. Thus, if we +shall found our distinction upon the fusibility and different degree of +having been charred, we shall confound fossil coals of very different +degrees of value in burning, or of very different compositions as +strata; if, again, we found it upon the purity of composition, in +judging from the ashes, we shall confound fossil bodies of very +different qualities, the one burning with much smoke and flame, the +other without any; the one fusible almost like wax, the other fixed and +infusible as charcoal. + +It will now appear, that what cannot be done in either the one or other +of those two methods, may in a great degree, or with considerable +propriety, be performed in employing both. + +Thus, whether for the economical purposes of life, or the natural +history of fossil coal, those strata should be considered both with +regard to the purity of their composition as inflammable matter +deposited at the bottom of the sea, and to the changes which they +have afterwards undergone by the operation of subterranean heat and +distillation. + +We have now considered the original matter of which coal strata are +composed to be of two kinds; the one pure bitumen or coal, as being +perfectly inflammable or combustible; the other an earthy matter, +with which proper coal may be variously mixed in its composition, or +intimately connected, in subsiding from that suspended state by which it +had been carried in the ocean. It is a matter of great importance, in +the physiology of this globe, to know that the proper substance of coal +may be thus mixed with heterogeneous bodies; for, supposing that this +earthy matter, which has subsided in the water along with coal, be no +farther connected with the combustible substance of those strata, than +that it had floated in the waters of the ocean, and subsided _pari +passu_ with the proper materials of the coal, we hence learn a great +deal with regard to the state in which the inflammable matter must have +been at the time of its formation into strata. This will appear by +considering, that we find schistus mixed with coal in the most equal or +uniform manner, and in almost every conceivable degree, from the purest +coal to the most perfect schistus. Hence we have reason to conclude, +that, at the formation of those strata, the bituminous matter, highly +subtilised, had been uniformly mixed with the earth subsiding in the +water. + +Not only is the bituminous matter of coal found mixed in every different +proportion with the earthy or uninflammable materials of strata, but the +coaly or bituminous composition is found with perhaps every different +species of substance belonging to strata. This is certain, that we have +the coaly matter intimately mixed with argillaceous and with calcareous +strata. + +Thus it will appear, that it is no proper explanation of the formation +of coal strata, to say that vegetable matter is the basis of those +strata; for though, in vegetation, a substance proper for the formation +of bituminous matter is produced, it remains to know by what means, from +a vegetable body, this bituminous matter is produced, and how it comes +to be diffused in that subtile state by which it may be uniformly mixed +with the most impalpable earth in water. Could we once resolve this +question, every other appearance might be easily explained. Let us +therefore now endeavour to discover a principle for the resolving of +this problem. + +There are two ways in which vegetable bodies may be, in part at least, +resolved into that subtilised state of bituminous matter after which we +inquire; the one of these is by means of fire, the other by water. We +shall now consider these severally as the means of forming bituminous +strata, although they may be both employed by nature in this work. + +When vegetable bodies are made to burn, there is always more or less of +a fuliginous substance formed; but this fuliginous substance is no +other than a bituminous body in that subtilised state in which it is +indefinitely divided, and may be mixed uniformly with any mass of matter +equally subtilised with itself. But this is precisely what we want, in +order to compose the strata of coal in question. If, therefore, there +were to be found in the ocean such a fund of this fuliginous substance +as might suffice for the formation of bituminous strata, no difficulty +would be left in explaining the original of fossil coal. But tho' +sufficient quantity of this fuliginous matter might not be found for the +explanation of natural appearances, yet there cannot be a doubt that +more or less of this matter must be produced in the mineral operations +of the globe, and be found precisely in that place where it is required +for the forming of those strata of coal. + +In order to conceive this, we are to consider, that there are actually +great quantities of coal strata in a charred state, which indicates +that all their more volatile oleaginous or fuliginous matter had been +separated by force of subterranean heat; and, we are to suppose that +this had been transacted at the bottom of the ocean: Consequently, a +subtile oleaginous, bituminous, or fuliginous substance, must have been +diffused in that ocean; and this bituminous matter would be employed in +forming other strata, which were then deposited at the bottom of the +waters. + +But besides this quantity of bituminous matter which is necessarily +formed in the mineral operations of the earth, and with regard to the +quantity of which we can never form a proper estimate, there must enter +into this same calculation all the fuliginous matter that is formed in +burning bodies upon the surface of this earth. This bituminous matter of +smoke is first delivered into the atmosphere, but ultimately it must +be settled at the bottom of the sea. Hence though, compared with the +quantity that we think required, each revolution of the globe produces +but a little in our estimation, yet the progress of time, in reforming +worlds, may produce all that is necessary in the formation of our +strata. + +There now remains to explain the other way in which bituminous matter +may be obtained from vegetable bodies, that is, by means of water. For +this purpose we must begin with a part of natural history that will +throw some light upon the subject. + +All the rivers in Scotland run into the sea tinged with a brown +substance; this is most evident in some of them after a flood, and while +yet the river is swelled; but, in travelling to the north of Scotland +in the summer season, without any rain, I saw all the rivers, without +exception, of a brown colour, compared with a river of more clear water. +This colour proceeds from the moss water, as it is called, which runs +into the rivers, or the infusion of that vegetable substance which +forms combustible turf, called peat. Now, this moss water leaves, upon +evaporation, a bituminous substance, which very much resembles fossil +coal. Therefore, in order to employ this vegetable infusion, delivered +into the ocean for the purpose of forming bituminous strata at its +bottom, it is only required to make this bituminous matter separate and +subside. + +If now we consider the immense quantity of inflammable vegetable +substance, dissolved in water, that is carried into the sea by all the +rivers of the earth, and the indefinite space of time during which those +rivers have been pouring in that oily matter into the sea; and if we +consider, that the continual action of the sun and atmosphere upon this +oily substance tends, by inspissation, to make it more and more dense or +bituminous, we cannot hesitate in supposing a continual separation +of this bituminous matter or inspissated oil from the water, and +a precipitation of it to the bottom of the sea. This argument is +corroborated by considering, that, if it were otherwise, the water of +the sea must have, during the immense time that rivers are proved +to have run, be strongly impregnated with that oily or bituminous +substance; but this does not appear; therefore we are to conclude, that +there must be the means of separating that substance from the water in +which it had been dissolved. + +If there is thus, from the continual perishing of animal and vegetable +bodies upon the surface of this earth and in the sea, a certain supply +of oily or bituminous matter given to the ocean, then, however small a +portion of this shall be supposed the whole oily or inflammable matter +produced upon the surface of the earth, or however long time it may +require for thus producing a stratum or considerable body of coal, +we must still see in this a source of the materials proper for the +production of that species of strata in the bottom of the sea. + +We have now considered the proper materials of which pure fossil coal +is chiefly formed; we have at present to consider what should be the +appearances of such a substance as this collected at the bottom of the +sea, and condensed or consolidated by compression and by heat. We should +thus have a body of a most uniform structure, black, breaking with a +polished surface, and more or less fusible in the fire, or burning with +more or less smoke and flame, in proportion as it should be distilled +or inspissated, less or more, by subterranean heat. But this is the +description of our purest fossil coals, which burn in giving the +greatest quantity of heat, and leave the smallest quantity of ashes. + +In order to form another regular species of coal, let us suppose that, +along with the bituminous substance now considered, there shall be +floating in the water of the ocean a subtile earthy substance, and that +these two different substances shall subside together in an uniform +manner, to produce a stratum which shall be covered with immense weight, +compressed, condensed, and consolidated as before, we should thus have +produced a most homogeneous or uniform body to appearance, but not so +in reality. The mixture of heterogeneous matter, in this case, is too +minute to be discovered simply by inspection; it must require deep +reflection upon the subject, with the help of chemical analysis, +to understand the constitution of this body, and judge of all the +circumstances or particulars in which it differs from the former. It is +worth while to examine this subject with some attention, as it will give +the most instructive view of the composition of bituminous strata, both +those which are not considered as coal, and also the different species +of that mineral body. + +In the first place then, if the mixture of those two different +substances had been sufficiently perfect, and the precipitation uniform, +the solid body of coal resulting from this mixture, would not only +appear homogeneous, but might break equally or regularly in all +directions; but the fracture of this coal must visibly differ from the +former, so far as the fracture of this heterogeneous coal cannot have +the polished surface of the pure bituminous body; for, the earthy matter +that is interposed among the bituminous particles must affect the +fracture in preventing its surface from being perfectly smooth. This +imperfect plane of the fracture may be improved by polishing; in which +case the body might be sufficiently smooth to have an agreeable polish; +but it cannot have a perfect polish like a homogeneous body, or appear +with that glassy surface which is naturally in the fracture of the pure +bituminous coal. + +But this is also a perfect description of that species of coal which is +called in England Kennel coal, and in Scotland Parrot coal. It is so +uniform in its substance that it is capable of being formed on the +turning loom; and it receives a certain degree of polish, resembling +bodies of jet. + +Thus, we have a species of coal in which we shall find but a small +degree of fusibility, although it may not be charred in any degree. +Such an infusible coal may therefore contain a great deal of aqueous +substance, and volatile oily matter; consequently may burn with smoke +and flame. But this same species of coal may also occasionally be +charred more or less by the operation of subterranean heat; and, in +that case, we should have a variety of coal which could only be +distinguished, from a similar state of pure bituminous coal, by the +ashes which they leave in burning. At least, this must be the case, when +both species are, by sufficient distillation, reduced to the state of +what may be properly termed a chemical coal. + +But in the natural state of its composition, we find those strata of +kennel or parrot coal, possessing a peculiar property, which deserves to +be considered, as still throwing more light upon the subject. + +We have been representing these strata of coal as homogeneous to +appearance, and as breaking indifferently in all directions; this last, +perhaps, is not so accurate; for they would seem to break chiefly into +two directions, that is, either parallel or perpendicular to the bed. +Thus we have this coal commonly in rectangular pieces, in which it +is extremely difficult to distinguish the direction of the bed, or +stratification of the mass. By an expert eye, however, this may be in +general, or at least sometimes, distinguished, and then, by knowing +the habit of the coal in burning, a person perfectly ignorant of the +philosophy of the matter may exhibit a wonderful sagacity, or even of +power over future events, in applying this body to fire; for, at his +pleasure, and unknown to those who are not in the secret; he may +apparently, in equal circumstances, make this coal either kindle +quietly, or with violent cracking and explosions, throwing its splinters +at a distance. + +The explanation lies in this, that, though the rectangular mass of coal +appears extremely uniform in its structure, it is truly a stratified +mass; it is therefore affected, by the sudden approach of fire in a very +different manner, according as the edge of the stratum, which is seen in +four of the sides of this supposed cube, shall be applied to the fire, +or the other two sides, which are in the line of the stratum, or +parallel to the bed of coal. The reason of this phenomenon now remains +to be considered. + +When the edge of the coal is exposed to the fire, the stratification of +the coal is opened gradually by the heat and expanding vapours, as a +piece of wood, of a similar shape, would be by means of wedges placed in +the end way of the timber. The coal then kindles quietly, and quickly +flames, while the mass of this bituminous schistus is opening like the +leaves of a book, and thus exhibits an appearance in burning extremely +like wood. But let the fire be applied to the middle of the bed, instead +of the edge of the leaves, and we shall see a very different appearance; +for here the expanded aqueous vapours, confined between the _laminae_, +form explosions, in throwing off splinters from the kindling mass; and +this mass of coal takes fire with much noise and disturbance. + +The ashes of this coal may be determined as to quality, being in general +a subtile white earth; but, as to quantity, the measure of that earth +produces an indefinite variety in this species of coal; for, from the +kennel or parrot coal, which is valuable for its burning with much +flame, to that black schistus which our masons use in drawing upon +stone, and which, though combustible in some degree, is not thought to +be a coal, there is a perfect gradation, in which coal may be found with +every proportion of this earthy alloy. + +Among the lowest species of this combustible schistus are those +argillaceous strata in Yorkshire from whence they procure alum in +burning great heaps of this stone, which also contains sulphur, to +impregnate the aluminous earth with its acid. We have also, in this +country, strata which differ from those aluminous schisti only in the +nature of the earth, with which the bituminous sediment is mixed. In +the strata now considered, the earth, precipitated with the bituminous +matter, being calcareous, has produced a limestone, which, after burning +especially, is perfectly fissile. + +Therefore, with regard to the composition of mineral coal, the theory +is this. That inflammable, vegetable, and animal substances, in a +subtilised state, had subsided in the sea, being mixed more or less with +argillaceous, calcareous, and other earthy substances in an impalpable +state. Now, the chemical analysis of fossil coal justifies that theory; +for, in the distillation of the inflammable or oily coal, we procure +volatile alkali, as might be naturally expected. + +Thus we have considered fossil coal as various, both in its state and +composition; we have described coal which is of the purest composition, +as well as that which is most impure or earthy; and we have shown that +there is a gradation, from the most bituminous state in which those +strata had been formed in being deposited at the bottom of the sea, +to the most perfect state of a chemical coal, to which they have been +brought by the operation of subterranean fire or heat. + +We have been hitherto considering fossil coal as formed of the +impalpable parts of inflammable bodies, united together by pressure, and +made to approach in various degrees to the nature of a chemical coal, +by means of subterranean heat; because, from the examination of those +strata, many of them have evidently been formed in this manner. +But vegetable bodies macerated in water, and then consolidated by +compression, form a substance of the same kind, almost undistinguishable +from some species of fossil coal. We have an example of this in our turf +pits or peat mosses; when this vegetable substance has been compressed +under a great load of earth, which sometimes happens, it is much +consolidated, and hardens, by drying, into a black body, not afterwards +dilutable or penetrated by water, and almost undistinguishable in +burning from mineralised bodies of the same kind. + +Also, when fossil wood has been condensed by compression and changed by +the operation of heat, as it is frequently found in argillaceous strata, +particularly in the aluminous rock upon the coast of Yorkshire, it +becomes a jet almost undistinguishable from some species of fossil coal. + +There cannot therefore be a doubt, that if this vegetable substance, +which is formed by the collection of wood and plants in water upon the +surface of the earth, were to be found in the place of fossil coal, and +to undergo the mineral operations of the globe, it must at least augment +the quantity of those strata, though it should not form distinct strata +by itself. + +It may perhaps be thought that vegetable bodies and their impalpable +parts are things too far distant in the scale of magnitude to be +supposed as subsiding together in the ocean; and this would certainly be +a just observation with regard to any other species of bodies: But the +nature of vegetable bodies is to be floatant in water; so that we may +suppose them carried at any distance from the shore; consequently, the +size of the body here makes no difference with regard to the place or +order in which these are to be deposited. + +The examination of fossil coal fully confirms those reasonable +suppositions. For, _first_, The strata that attend coal, whether the +sandstone or the argillaceous strata, commonly, almost universally, +abound with the most distinct evidence of vegetable substances; this +is the impressions of plants which are found in their composition. +_Secondly_, There is much fossil coal, particularly that termed in +England clod coal, and employed in the iron foundry, that shows +abundance of vegetable bodies in its composition. The strata of this +coal have many horizontal interstices, at which the more solid shining +coal is easily separated; here the fibrous structure of the compressed +vegetable bodies is extremely visible; and thus no manner of doubt +remains, that at least a part of this coal had been composed of the +vegetable bodies themselves, whatever may have been the origin of the +more compact parts where nothing is to be distinguished. + +The state in which we often find fossil wood in strata gives reason to +conclude that this body of vegetable production, in its condensed state, +is in appearance undistinguishable from fossil coal, and may be also in +great quantity; as, for example, the Bovey coal in Devonshire. + +Thus the strata of fossil coal would appear to be formed by the +subsidence of inflammable matter of every species at the bottom of the +sea, in places distant from the shore, or where there had been much +repose, and where the lightest and most floatant bodies have been +deposited together. This is confirmed in examining those bodies of +fossil coal; for, though there are often found beds of sand-stone +immediately above and below the stratum of the coal, we do not find any +sand mixed in the strata of the coal itself. + +Having found the composition of coal to be various, but all included +within certain rules which have been investigated, we may perceive in +this an explanation of that diversity which is often observed among the +various strata of one bed of coal. Even the most opposite species of +composition may be found in the thickness of one bed, although of very +little depth, that is to say, the purest bituminous coal may, in the +same bed, be conjoined with that which is most earthy. + +Fossil coal is commonly alternated with regular sand-stone and +argillaceous strata; but these are very different bodies; therefore, +it may perhaps be inquired how such different substances came to be +deposited in the same place of the ocean. The answer to this is easy; we +do not pretend to trace things from their original to the place in which +they had been ultimately deposited at the bottom of the sea. It is +enough that we find the substance of which we treat delivered into +the sea, and regularly deposited at the bottom, after having been +transported by the currents of the ocean. Now the currents of the ocean, +however regular they may be for a certain period of time, and however +long this period may be protracted, naturally change; and then the +currents, which had given birth to one species of stratum in one place, +will carry it to another; and the sediment which the moment before +had formed a coal stratum, or a bed of that bituminous matter, may +be succeeded either with the sediment of an argillaceous stratum, or +covered over with a bed of sand, brought by the changed current of the +sea. + +We have now considered all the appearances of coal strata, so far as +these depend upon the materials, and their original collection. But, +as those bituminous strata have been changed in their substance by the +operation of subterranean heat and inspissation, we are now to look for +the necessary consequences of this change in the body of the stratum; +and also for other mineral operations common to fossil coal with +consolidated strata of whatever species. + +If coal, like other mineral strata, have been inspissated and +consolidated by subterranean heat, we should find them traversed with +veins and fissures; and, if the matter found in those veins and fissures +corresponds to that found in similar places of other strata, every +confirmation will be hence given to the theory that can be expected from +the consideration of those bituminous strata. But this is the case; we +find those fissures filled both with calcareous, gypseous, and pyritous +substances. Therefore, we have reason to conclude, that the strata of +fossil coal, like every other indurated or consolidated body in the +earth, has been produced, _first_, by means of water preparing and +collecting materials proper for the construction of land; and, +_secondly_, by the operation of internal fire or subterranean heat +melting and thus consolidating every known substance of the globe. + +Not only are those sparry and pyritous substances, which are more +natural to coal strata, found forming veins traversing those strata in +various directions, but also every other mineral vein may occasionally +be found pervading coal mines, or traversing bituminous strata. Gold, +silver, copper, lead, calamine, have all, in this manner, been found in +coal. + +There remains now only to consider those bituminous strata of fossil +coal in relation to that change of situation which has happened more +or less to every stratum which we examine; but which is so much better +known in those of coal, by having, from their great utility in the arts +of life, become a subject for mining, and thus been traced in the earth +at great expense, and for a long extent. + +Coal strata, which had been originally in a horizontal position, are now +found sometimes standing in an erect posture, even almost perpendicular +to the plane in which they had been formed. Miners therefore distinguish +coal strata according as they deem them to approach to the one or other +of those two extremes, in terming them either flat or edge seams or +veins. Thus, it will appear, that every possible change from the +original position of those strata may have happened, and are daily found +from our experience in those mines. + +But besides the changed position of those strata, in departing from the +horizontal line or flat position in which they had been formed, there is +another remarkable change, termed by miners a _trouble_ in the coal. The +consideration of this change will further illustrate the operations of +nature in placing that which had been at the bottom of the sea above its +surface. + +Strata, that are in one place regularly inclined, may be found bended, +or irregularly inclined, in following their course. Here then is a +source of irregularity which often materially effects the estimates +of miners, judging from what they see, of those parts which are to be +explored; and this is an accident which they frequently experience. + +But, without any change in the general direction of the stratum, miners +often find their coal broke off abruptly, those two parts being placed +upon a higher and lower situation in respect to each other, if flat +beds, or separated laterally if they are edge seams. This is by miners +termed a _slip, hitch_, or _dyke_. + +These irregularities may either be attended with an injected body of +subterraneous lava or basaltes, here termed whin-stone, or they may not +be attended, at least apparently, _i.e._ immediately, with any such +accident. But experienced miners know, that, in approaching to any of +those injected masses of stone, which are so frequent in this country, +their coal is more and more subject to be troubled. + +As there is, in this country of Scotland, two different species of +mountains or hills, one composed both in matter and manner exactly +similar to the Alps of Switzerland, the other of whin-stone, basaltic +rock, or subterraneous lava; and as the fossil coal, argillaceous and +sand-stone strata, are found variously connected with those hills, +nothing can tend more to give a proper understanding, with regard to the +construction of the land in general, of the globe than a view of those +different bodies, which are here found much mixed together in a little +space of country, thus exhibiting, as it were in miniature, what may be +found in other parts of the world, upon a larger scale, but not upon any +other principle. I will therefore endeavour to give a short description +of the mineral state of this country with regard to coal, so far as my +experience and memory will serve. + +This country might very properly be considered as consisting of primary +and secondary mountains; not as supposing the primary mountains original +and inexplicable in their formation, any more than those of the latest +production, but as considering the one to be later in point of time, or +posterior in the progress of things. The first are those which commonly +form the alpine countries, consisting of various schisti, of quartzy +stone, and granites. The second, again, are the whinstone or basaltic +hills scattered up and down the low country, and evidently posterior to +the strata of that country, which they break, elevate, and displace. + +Thus there are in this country, as well as every where else, three +things to be distinguished; first, the alpine or elevated country; +secondly, the flat or low country; and, thirdly, that which has been of +posterior formation to the strata which it traverses, in whatever shape +or quality; whether as a mountain, or only as a vein; whether as a +basaltes, a porphyry, or a granite, or only as a metal, a siliceous +substance, or a spar. + +Those three things which are here distinguished do not differ with +regard to the chemical character of their substances; for, in each of +these, every different substance is to be found, more or less; and it +is not in being composed of materials peculiar to itself, that makes an +alpine country be distinguished from a flat country; it is chiefly in +the changes which the strata of the alpine country have been made to +undergo, posterior to their original collection, that the rocks of the +alpine country differ from those of the flat country. + +But the observation that is most to the purpose of the present subject +of bituminous strata, is this; it is chiefly in the strata of the flat +country that fossil coal are found; there are none that I know of in +all the alpine countries of Scotland; and it is always among the strata +peculiar to the flat country that fossil coal is found. Now, this +appearance cannot be explained by saying that the materials of mineral +coal had not existed in the world while those primary strata were formed +in the sea. I have already shown, (chap. 4.) that there had been the +same system of a world, producing plants, and thus maintaining animals, +while the primary strata were formed in the sea; I have even adduced an +example of coal strata among those primary schisti, although this be an +extremely rare occurrence: Consequently, we are under the necessity of +looking out for some other cause. + +If the changes which have been evidently superinduced in the strata of +alpine countries arise from the repeated operations of subterranean +fire, or to the extreme degree in which those strata have been affected +by this consolidating and elevating cause, it will be natural to suppose +that the bituminous or combustible part among those stratifications, may +have been mostly consumed upon some occasion during those various and +long continued operations; whereas, in the flat beds of the low country, +although there is the most perfect evidence for the exertion of heat in +the consolidation of those strata, the general quantity of this has been +a little thing, compared with the universal manifestation of this cause +in the operations of the alpine countries, the strata of which have been +so much displaced in their situations and positions. + +To illustrate this, strata of sand-stone are found in both the alpine +and flat countries of Scotland. About Leadhills, for example, there are +abundance of those strata; but, in the flat country, the generality of +the sand-stone is so little changed as to appear to every enlightened +naturalist aquiform strata; whereas the most enlightened of those +philosophers will not perhaps attribute the same original to a similar +composition in the alpine country, which is so much changed from its +original state. It is not because there had been wanting a sufficient +degree of heat to consolidate the sand-stone in the coal country; for I +can show specimens of sand-stone almost contiguous with coal, that have +been extremely much consolidated in this manner. But this is only a +particular stratum; and the general appearance of the sand-stone, as +well as other strata in the coal countries, is that of having been +little affected by those subterranean operations of heat by which those +bodies in the alpine country have been changed in their structure, +shape, and position. + +If we shall thus allow the principle of consolidation, consequently also +of induration, to have been much exerted upon the strata of the alpine +country, and but moderately or little upon those of the low country of +Scotland, we shall evidently see one reason, perhaps the only one, for +the lesser elevation of the one country above the level of the sea, than +the other. This is because the one resists the powers which have been +employed in leveling what has been raised from the bottom of the sea, +more than the other; consequently, we find more of the one remaining +above the level of the sea than of the other. + +Let us now take the map of Scotland, in order to observe the mixture of +those two different species of countries, whereof the one is generally +low and flat, the other high and mountainous; the one more or less +provided with fossil coal, the other not. + +From St Abb's Head, on the east of Scotland, to the Mull of Galloway, +on the west, there runs a ridge of mountains of granite, quartz, and +schistus strata, which contain not coal. On each side of this ridge we +find coal countries; Northumberland, on the one side, and, on the other, +the shires of Ayr, Lanark, and the Lothians; the one is a mountainous +country, the others are comparatively low or flat countries. Let us now +draw another alpine line from Buchan and Caithness, upon the east, to +the island of Jura, on the west; this traverses a mountainous country +destitute of coal, and, so far as I know, of any marks of marine bodies. +But, on each side of this great alpine ridge, we find the hard country +skirted with one which is lower, flatter, or of a softer nature, +in which coal is found, upon the one side, in the shires of Fife, +Clackmannan, and Stirling; and, on the other, in that hollow which runs +from the Murray Frith south-west, in a straight line, directed upon the +end of Mull, and composed, for the most part, of water very little above +the level of the sea. Here, to be sure, the coal is scarce, or not so +evident; but there is coal upon the sea coast in several places of this +great Bay betwixt Buchan and Caithness; and the lowness of the country, +across this part of the island, is almost sufficient testimony that it +had been composed of softer materials. + +Thus the coal country of Scotland may be considered as in one band +across the island, and included in the counties of Ayr, Lanark, and all +those which border upon the Frith of Forth. Now, in all this tract of +coal and tender strata, we do not find ridges of alpine stone or primary +mountains, but we find many hills of solid rock, little mountains, from +500 to 1000 feet high; such as that beautiful conical hill North Berwick +Law, Torpender Law, Arthur's Seat, the Lowmands, and others of inferior +note. That is to say, the whole of this included space, both sea and +land, has been invaded from below with melted masses of whin-stone, +breaking up through the natural strata of the country, and variously +embossing the surface of the earth at present, when all the softer +materials, with which those subterranean lavas had been covered, are +washed away or removed from those summits of the country. Hence there is +scarcely a considerable tubercle, with which this country also abounds, +that may not be found containing a mass of whin-stone as a nucleus. + +But besides those insulated masses of whinstone that form a gradation +from a mountain to a single rock, such, for example, as that on which +the Castle of Edinburgh is built, we find immense quantities of the same +basaltic rock interjected among the natural strata, always breaking and +disordering them, but often apparently following their directions for a +considerable space with some regularity. We also find dykes of the same +substance bisecting the strata like perpendicular veins of rock; and, in +some places, we see the connection of these rocks of the same substance, +which thus appear to be placed in such a different form in relation to +the strata. + +It will thus appear, that the regular form, and horizontal direction of +strata throughout this country of coal, now under contemplation, has +been broken and disordered by the eruption and interjection of those +masses of basaltic stone or subterraneous lava; and thus may be +explained not only the disorders and irregularities of coal strata, but +also the different qualities of this bituminous substance from its +more natural state to that of a perfect coal or fixed infusible and +combustible substance burning without smoke. This happens sometimes to a +part of a coal stratum which approaches the whin-stone. + +Having thus stated the case of combustible or bituminous strata, I would +ask those naturalists, who adhere to the theory of infiltration and the +operation of water alone, how they are to conceive those strata formed +and consolidated. They must consider, that here are immense bodies of +those combustible strata, under hundreds, perhaps thousands, of fathoms +of sand-stone, iron-stone, argillaceous and calcareous strata. If they +are to suppose bituminous bodies collected at the bottom of the sea, +they must say from whence that bitumen had come; for, with regard to the +strata below those bituminous bodies, above them, and between them, +we see perfectly from whence had come the materials of which they are +formed. They cannot say that it is from a collection of earthy matter +which had been afterwards bituminized by infiltration; for, although +we find many of those earthy strata variously impregnated with the +bituminous and coaly matter, I have shown that the earthy and the +bituminous matter had subsided together; besides, there are many of +those coaly and bituminous strata in which there is no more than two or +three _per cent._ of earthy matter or ashes after burning; therefore +the strata must have been formed of bituminous matter, and not simply +impregnated with it. + +To avoid this difficulty, we shall allow them to form their strata, +which certainly is the case in great part, by the collection of +vegetable bodies; then, I desire them to say, in what manner they are +to consolidate those bodies. If they shall allege that it is by simple +pressure, How shall we conceive the numerous veins of spar and pyrites, +which traverse those strata in all directions, to be formed in +those bodies consolidated by the compression of the superincumbent +masses?--Here is a manifest inconsistency, which proves that it could +not be. But, even were we to suppose all those difficulties to be over +come, there is still an impossibility in the way of that inconsiderate +theory, and this will appear more fully in the following chapter. + + +SECT. III.--The Mineralogical Operations of the Earth illustrated from +the Theory of Fossil Coal. + +There is not perhaps a greater difference among the various qualities of +bodies than that which may be observed to subsist between the burning of +those two substances, that is, the inflammable bodies on the one hand, +and those that are combustible on the other. I have treated of that +distinction in Dissertations upon subjects of Natural Philosophy, part +3d. where I have considered the different effects of those two kinds +of bodies upon the incident light; and, in a Dissertation upon the +Philosophy of Fire, etc. I have distinguished those two kinds of +substances in relation to their emitting, in burning, the fixed light +which had constituted a part of those inflammable and combustible +bodies. + +All animals and vegetable bodies contain both those different chemical +substances united; and this phlogistic composition is an essential part +in every animal and vegetable substance. There are to be found in those +bodies particular substances, which abound more or less with one of +those species of phlogistic matter, but never is the one species of +those burning substances to be found naturally, in animal and vegetable +bodies, without being associated with the other; and it is all that the +chemical art can do to separate them in a great degree upon occasion. +Pure ardent spirit may perhaps be considered as containing the one, and +the most perfect coal the other; the chemical principle of the one +is proper carbonic matter; and of the other it is the hydrogeneous +principle, or that of inflammable air. + +Thus we so far understand the composition of animal and vegetable +substances which burn or maintain our fires; we also understand the +chemical analysis of those bodies, in separating the inflammable from +the combustible substance, or the volatile from the fixed matter, the +oil from what is the proper coal. It is by distillation or evaporation, +the effect of heat, that this separatory operation is performed; and we +know no other means by which this may be done. Therefore, wherever we +find peculiar effects of that separatory operation, we have a right to +infer the proper cause. + +The subject, which we are to consider in this section, is not the +composition of strata in those of mineral coal, but the transformation +of those, which had been originally inflammable bodies, into bodies +which are only combustible, an end which is to be attained by the +separation of their volatile or inflammable substances. In the last +section, I have shown of what materials the strata of mineral coal had +been originally formed; these are substances containing abundance of +inflammable oil or bitumen, as well as carbonic matter which is properly +combustible; and this is confirmed by the generality of those strata, +which, though perfectly consolidated by fusion, retain still their +inflammable and fusible qualities. But now the object of investigation +is that mineral operation by which some of those strata, or some parts +of a fusible and inflammable stratum, have been so changed as to become +infusible and only combustible. + +We have now examined those strata which may be considered as either +proper mineral coal, or as only a bituminous schistus; we are now to +class along with these another species of this kind of matter, which has +had a similar origin, although it may assume a different character. + +According to the common observations of mankind, the eminent quality by +which coal is to be distinguished, is the burning of that substance, +or its capacity for making a fire. Therefore, however similar in other +respects, a substance which had not that eminent quality of coal could +hardly be considered as being allied to it; far less could it be +supposed, as being in every other respect the same. We are however +to endeavour to show, that there are truly substances of this kind, +substances which to common observation, having none of the properties of +coal with respect to fire, consequently, no utility for the purpose of +burning, might be considered as another species of mineral, while at the +same time they are truly at bottom a composition very little different +from those which we have considered as the most perfect coal. + +It must be recollected that we have distinguished coal in general as +of two different species, one perfect or proper coal, containing no +perceptible quantity of either oil or phlegm; the other as burning with +smoke and flame, consequently containing both aqueous and oleaginous +substances which it emits in distillation. It is the first of these +which we are now to consider more particularly, in order to see the +varieties which may be found in this species of mineral substance. + +When that bituminous fossil, which is the common coal of this country, +is submitted to heat it is subject to melt more or less, and emits smoke +which is composed of water and oil. If it be thus completely distilled, +it becomes a perfect coal of a porous or spongy texture. Such a +substance as this is extremely rare among minerals; I have however found +it. It is in the harbour of Ayr, where a whinstone dyke traverses the +coal strata, and includes some of that substance in the state of coals +or cinder. I pointed this out many years ago to Dr Black; and lately I +showed it to Professor Playfair. + +But the culm of South Wales, the Kilkenny coal of Ireland, and the blind +coal of Scotland, notwithstanding that these are a perfect coal, or +charred to a coal, have nothing of the porous construction of the +specimen which I have just now mentioned; they are perfectly solid, and +break with a smooth shining surface like those which emit smoke and +flame. + +Here is therefore a mineral operation in the preparation of those coals +which we cannot imitate; and here is the clearest evidence of the +operation of mineral fire or heat, although we are ignorant of the +reason why some coal strata are charred, while others are not, and why, +in some particular cases, the charred coal may be porous or spongy like +our coals, while in general those blind coals (as they are called) are +perfectly solid in their structure. + +But to what I would call more particularly the attention of mineral +philosophers is this, that it is inconceivable to have this effect +produced by means of water; we might as well say that heat were to be +the cause of ice. The production of coal from vegetable bodies, in which +that phlogistic substance is originally produced, or from animal bodies +which have it from that source, is made by heat, and by no other means, +so far as we know. But, even heat alone is not sufficient to effect that +end, or make a perfect coal; the phlogistic body, which is naturally +compound, consisting of both inflammable and combustible substances, +must be separated chemically, and this must be the operation of heat +under the proper circumstances for distillation or evaporation. + +Here is the impossibility which in the last chapter I have alleged the +aqueous theory has to struggle against; and here is one of the absolute +proofs of the igneous theory. Not only must the aqueous part of those +natural phlogistic bodies be evaporated, in order to their becoming +coal, but the oily parts must also, by a still increased degree of heat, +be evaporated, or separated by distillation from the combustible part. +Here, therefore, is evidently the operation of heat, not simply that +of fusion in contradiction to the fluidity of aqueous solution, but +in opposition to any effect of water, as requiring the absence or +separation of that aqueous substance. + +But those natural appearances go still farther to confirm our theory, +which, upon all occasions, considers the compression upon the bodies +that are submitted to the operation of heat, in the mineral regions, as +having the greatest efficacy in modifying that operation. Coal strata, +which are in the neighbourhood of each other, being of those two +opposite species, the one fusible and inflammable, the other infusible +and combustible, afford the clearest proof of the efficacy of +compression; for, it is evident, that the coal, which was once +bituminous or fusible, cannot be charred without the distillation of +that substance; therefore, prevent the distillation by compression and +the charring operation cannot proceed, whatever should be the intensity +of the heat; and then, fusion alone must be the effect upon the +bituminous body. But now, as we have both those species of coal in the +vicinity of each other, and even the same strata of coal part charred, +while the rest is not, this natural appearance, so far from being a +stumbling block, as it must be to the opposite theory, is most clearly +explained by the partial escape of vapours from the mineral regions, and +thus confirms the theory with regard to the efficacy of compression. + +It is owing to the solidity of those natural charred coals, and the want +of oil, that they are so very difficult of kindling; but, when once +kindled in sufficient quantity, they make a fire which is very durable. +There are even some of them which, to common observation, seem to be +altogether incombustible. I have of this kind a specimen from a stratum +at Stair, which shall be afterwards mentioned. + +M. Struve, in the Journal de Physique for January 1790, describes a +mineral which he calls _plombagine charbonneuse ou hexaedre_; and gives +for reason, _parce qu'elle ressemble extremement au charbon de pierre +schisteux, ou d'hexaedre_. He says farther, "Il est tres commun, dans +une roche qui forme un passage entre les granits et les breches, qu'on +n'a trouvee jusqu'a present qu'on masses roulees dans le pays de Vaud." +He concludes his paper thus: "Ce fossile singulier ne paroit pas +appartenir a la Suisse seule. J'ai dans ce moment devant les yeux une +substance parfaitement semblable, si on excepte la couleur qui tient le +milieu entre le gris de fer et le rouge modere; elle vient du pays de +Gotha de la Friedrischs-grube, proche d'Umneau. On le regarde comme un +eisenrahm uni a du charbon de pierre." + +The specimen which I have from Stair upon the water of Ayr, so far as I +can understand, perfectly resembles this _plombagine_ of M. Struve. It +consumes very slowly in the fire, and deflagrates like plumbago with +nitre. Now this comes from a regular coal stratum; and what is more +remarkable, in this stratum is contained a true plumbago, Farther up the +country, the Earl of Dumfries has also a mine containing plumbago along +with other coal strata; and though the plumbago of these two mines have +not all the softness and beauty of the mineral of the same species from +Cumberland, they are nevertheless perfect plumbago. + +I have a specimen of steatetical whinstone or basaltes from some part of +Cumberland, in which is contained many nodules of the most perfect and +beautiful plumbago. It is dispersed through this stone in rounded masses +of all sizes from a nut to a pin's head; and many of these are mixed +with pyrites. There is therefore reason to believe that this plumbago +had been in fusion. + +Now, if we consider that every species of coal and every species of +plumbago are equally, that is, perfectly combustible, and yield, in +burning, the same volatile principles, differing only perhaps a little +in the small quantity of fixed matter which remains, we shall be +inclined to believe, that they have all the same origin in a vegetable +substance; and that they are diversified by some very small composition +of other matter. This being allowed, one thing is certain, that it is by +the operation of mineral fire or heat that those combustible substances, +however composed, have been brought to their present state of coal, +although we are ignorant of the circumstances by which their differences +and their peculiar chemical and mechanical qualities have been produced. + +Let us resume in a few words. There is not perhaps one substance in the +mineral kingdom by which the operation of subterraneous heat is, to +common understanding, better exemplified than that of mineral coal. +Those strata are evidently a deposit of inflammable substances which all +come originally from vegetable bodies. In this state of their formation, +those coal strata must all be oleagenous or bituminous. In many of them, +however, these volatile parts are found wanting; and, the stratum is +found in the state of the most perfect coal or caput mortuum. There, is, +I presume, no other means to be found by which this eminent effect could +be produced, except by distillation; and, this distillation perhaps +proceeded under the restraining force of an immense compression. + +To this theory it must not be objected, that all the strata of coal, +which are found in the same place or neighbourhood, are not reduced to +that caput mortuum or perfect coaly state. The change from a bituminous +to a coaly substance can only take place in proportion as the +distillation of the volatile parts is permitted. Now this distillation +must be permitted, if any passage can be procured from the inflammable +body submitted to the operation of subterraneous heat; and, one stratum +of coal may find vent for the passage of those vapours, through some +crevice which is not open to another. In this way, doubtless, some of +those bodies have been inspissated or reduced to a fixed coal, while +others, at a little distance, have retained most of their volatile +parts. + +We cannot doubt of this distilling operation in the mineral regions, +when we consider that in most places of the earth we find the evident +effects of such distillation of oily substances in the naphta and +petroleum that are constantly emitted along with water in certain +springs. These oily substances are no other than such as may be +procured, in a similar manner, from the fusible or inflammable coal +strata; we have therefore every proof of this mineral operation that the +nature of things admit of. We have also sufficient evidence that those +fusible and inflammable coals, which have not been distilled to a caput +mortuum, had been subjected to the operation of subterraneous heat, +because we find those fusible coals subject to be injected with pyrites, +as well as the more perfect coal. + +If we now consider those various appearances of mineral bodies which +are thus explained by the theory of mineral fire, or exertion of +subterraneous heat, appearances which it is impossible to reconcile by +any supposition of aqueous solution, or that unintelligible language +of mineral infiltration which has of late prevailed, we shall be fully +satisfied, that there is a uniform system in nature of providing a power +in the mineral regions, for consolidating the loose materials deposited +at the bottom of the sea, and for erecting those masses of mineralized +substances into the place of land; we shall thus be led to admire the +wisdom of nature, providing for the continuation of this living world, +and employing those very means by which, in a more partial view of +things, this beautiful structure of an inhabited earth seems to be +necessarily going into destruction. + + +END OF VOLUME FIRST. + + + +***END OF THE PROJECT GUTENBERG EBOOK THEORY OF THE EARTH, VOLUME 1 (OF +4)*** + + +******* This file should be named 12861.txt or 12861.zip ******* + + +This and all associated files of various formats will be found in: +https://www.gutenberg.org/1/2/8/6/12861 + + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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