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+*** START OF THE PROJECT GUTENBERG EBOOK 14041 ***
+
+[Illustration]
+
+
+
+
+SCIENTIFIC AMERICAN SUPPLEMENT NO. 470
+
+
+
+
+
+NEW YORK, JANUARY 3, 1885
+
+Scientific American Supplement. Vol. XIX, No. 470.
+
+Scientific American established 1845
+
+Scientific American Supplement, $5 a year.
+
+Scientific American and Supplement, $7 a year.
+
+
+       *       *       *       *       *
+
+
+
+
+TABLE OF CONTENTS.
+
+I.    METALLURGY, CHEMISTRY, ETC.--The Elasticity of Metals.
+
+      The Liquefaction of the Elementary Gases.--By JULES JAMIN.
+
+      Examination of Fats.
+
+      Notes on Nitrification.--By R. WARINGTON.--Paper read before
+      the British Association at Montreal.
+
+II.   ENGINEERING AND MECHANICS.--Flow of Water through
+      Hose Pipes.
+
+      Iron Pile Planks in the Construction of Foundations under
+      Water.--3 engravings.
+
+      Sound Signals.--Extracts from a paper by A.B. JOHNSON.--Treating
+      of gongs, guns, rockets, bells, whistling buoys, bell
+      buoys, locomotive whistles, trumpets, the siren, and the use of
+      natural orifices.--2 engravings.
+
+      Trevithick's High Pressure Engine at Crewe.--2 engravings.
+
+      Planetary Wheel Trains.--By Prof. C.W. MACCORD.--With a
+      page and a half of illustrations.
+
+      Bridge over the River Indus, at Attock. Punjaub, Northern State
+      Railway, India.--Full page illustrations.
+
+      The Harrington Rotary Engine.--3 figures.
+
+III.  TECHNOLOGY.--Testing Car Varnishes.--By D.D. ROBERTSON.
+
+      Aniline Dyes in Dress Materials.--By Prof. CHAS. O'NEILL.
+
+IV.   DECORATIVE ART.--A. Chippendale Sideboard.--With engraving.
+
+V.    PHYSICS, MAGNETISM, ETC.--The Fallacy of the Present
+      Theory of Sound.--Abstract of a lecture by Dr. H.A. MOTT.
+
+      The Fixation of Magnetic Phantoms.--With engraving.
+
+VI.   NATURAL HISTORY.--Researches on the Origin and Life Histories
+      of the Least and Lowest Living Things---By Rev. W.H.
+      DALLINGER.
+
+VII.  MEDICINE, ETC.--Case of Resuscitation and Recovery after
+      Apparent Death by Hanging.--by Dr. E.W. WHITE.
+
+VIII. MISCELLANEOUS.--The Inventors' Institute.--Address of the
+      Chairman at the opening of the twenty-second session of the
+      Institute, October 2.
+
+      The New Central School at Paris.--3 engravings.
+
+       *       *       *       *       *
+
+
+
+
+FLOW OF WATER THROUGH HOSE PIPES.
+
+
+At a recent meeting in this city of the American Society of Civil
+Engineers, a paper by Edmund B. Weston was read, giving the description
+and result of experiments on the flow of water through a 2½ inch hose and
+through nozzles of various forms and sizes; also giving the results of
+experiments as to the height of jets of water. The experiments were made
+at Providence, R.I. The water was taken from a hydrant to the head of
+which were attached couplings holding two pressure gauges, and from the
+couplings the hose extended to a tank holding 2,100 gallons, so arranged
+as to measure accurately the time and amount of delivery of water by the
+hose. Different lengths of hose were used. The experiments resulted in the
+following formula for flow from coupling:
+
+1. For hose between 90 and 100 feet in length, and where great accuracy is
+required:
+
+         ---------------------------------------------------
+        /                   2gh
+  V =  / ---------------------------------------------------
+      /                   /          0.504 \
+    \/ 1 - 0.0256d^{4} + ( 0.0087 + ------- ) 0.12288d^{4}l.
+                          \          ---   /
+                                   \/ v
+
+[TEX: V = \sqrt{\frac{2gh}{1 - 0.0256 d^4 + (0.0087 +
+\frac{0.504}{\sqrt{v}}) 0.12288 d^4 l}}.]
+
+2. For all lengths of hose, a reliable general formula:
+
+        ----------------------------------------------
+       /                     h
+  V = / ----------------------------------------------
+    \/  0.0155463 - 0.000398d^{4} + 0.0000362962d^{4}l.
+
+[TEX: V = \sqrt{\frac{h}{0.0155463 - 0.000398 d^4 + 0.0000362962 d^4 l}}.]
+
+  g being velocity of efflux in feet per second.
+  h, head in feet indicated by gauge.
+  d, of coupling in inches.
+  l, length of hose in feet from gauge.
+  v, velocity in 2½ inch hose.
+
+Forty-five experiments were made on ring nozzles, resulting in the
+following formula:
+
+  f = 0.001135v².
+
+f being loss of head in feet owing to resistance of nozzle, and v the
+velocity of the contracted vein in feet per second.
+
+Thirty-five experiments were made with smooth nozzles, resulting in the
+following formula:
+
+  f = 0.0009639 v².
+
+f being the loss of head in feet owing to resistance, and v the
+velocity of efflux in feet per second.
+
+Experiments show that a prevailing opinion is incorrect that jets will
+rise higher from ring nozzles than from smooth nozzles.
+
+Box's formula for height of jets of water compares very favorably with
+experimental results.
+
+       *       *       *       *       *
+
+
+
+
+IRON PILE PLANKS IN THE CONSTRUCTION OF FOUNDATIONS UNDER WATER.
+
+
+The annexed engravings illustrate a method of constructing subaqueous
+foundations by the use of iron pile planks. These latter, by reason of
+their peculiar form, present a great resistance, not only to the vertical
+blow of the pile driver (as it is indispensable that they should), but
+also to horizontal pressure when excavating is being done or masonry being
+constructed within the space which they circumscribe. Polygonal or curved
+perimeters may be circumscribed with equal facility by joining the piles,
+the sides of one serving as a guide to that of its neighbor, and special
+pieces being adapted to the angles. Preliminary studies will give the
+dimensions, form, and strength of the iron to be employed. The latter, in
+fact, will be rolled to various thicknesses according to the application
+to be made of it. We may remark that the strength of the iron, aside from
+that which is necessary to allow the pile to withstand a blow in a
+vertical direction, will not have to be calculated for all entire
+resistance to the horizontal pressure due to a vacuum caused by the
+excavation, for the stiffness of the piles may be easily maintained and
+increased by establishing string-pieces and braces in the interior in
+measure as the excavation goes on.
+
+[Illustration: FIG. 1.--CONSTRUCTION OF A DOCK WALL BEHIND PAPONOTS IRON
+PILE PLANKS.]
+
+The system is applicable to at least three different kinds of work: (1)
+The making of excavations with a dredge and afterward concreting without
+pumping out the water. (2) The removal of earth or the construction of
+masonry under protection from water (Fig. 1). (3) The making of
+excavations by dredging and afterward concreting without pumping, mid
+then, after the beton has set, pumping out the water in order to continue
+the masonry in the open air. This construction of masonry in the open air
+has the great advantage of allowing the water to evaporate from the
+mortar, and consequently of causing it to dry and effect a quick and
+perfect cohesion of the materials employed.
+
+[Illustration: FIG. 2.--TRAVERSE SECTION OF TWO PILES CONNECTED BY MORTAR
+JOINTS.]
+
+This system may likewise be employed with advantage for the forming of
+stockades in rivers, or for building sea walls. A single row of pile
+planks will in many cases suffice for the construction of dock walls in
+the river or ocean when the opposite side is to be filled in, or in any
+other analogous case (Fig. 1).
+
+The piles are driven by means of the ordinary apparatus in use. Their
+heads are covered with a special apparatus to prevent them from being
+flattened out under the blows of the pile driver. They may be made in a
+single piece or be composed of several sections connected together with
+rivets. They are designed according to circumstances, to be left in the
+excavation in order to protect the masonry, or to be removed in their
+entirety or in parts, as is done with caissons. In case they are to remain
+wholly or in part in the excavation, they are previously galvanized or
+painted with an inoxidizable coating in order to protect them and increase
+their durability.
+
+The points of the piles, whatever be their form and arrangement, are
+strengthened by means of steel pieces, which assure of their penetrating
+hard and compact earth.
+
+[Illustration: FIG. 3.--DREDGING WITHIN A SPACE CIRCUMSCRIBED BY IRON PILE
+PLANKS.]
+
+Fig. 2 represents a dredge at work within a space entirely circumscribed
+by pile planks. Here, after the excavation is finished, beton will be put
+down by means of boxes with hinged bottoms, and the water will afterward
+be pumped out in order to allow the masonry to be constructed in the open
+air. Fig. 3 shows a transverse section of two of these pile planks united
+by mortar joints. This system is the invention of Mr. Papenot.--_Revue
+Industrielle._
+
+       *       *       *       *       *
+
+
+
+
+AN ATMOSPHERIC BATTERY.
+
+
+Great ingenuity is being shown in the arrangement of new forms of primary
+batteries. The latest is that devised by M. Jablochkoff, which acts by the
+effect of atmospheric moisture upon the metal sodium. A small rod of this
+metal is flattened into a plate, connected at one end to a copper wire.
+There is another plate of carbon, not precisely the same as that used for
+arc lights or ordinary batteries, but somewhat lighter in texture. This
+plate is perforated, and provided with small wooden pegs. The sodium plate
+is wrapped in silk paper, and pressed upon the carbon in such a manner
+that the wooden pegs penetrate the soft sodium. For greater security the
+whole is tied together with a few turns of fine iron wire; care being
+taken that the wire does not form an electric contact between the sodium
+and the carbon. The element is then complete, the carbon and the small
+copper wire being the electrodes. The sodium, on exposure to the air,
+becomes oxidized, forming caustic soda, which with the moisture of the air
+dissolves, and drains gradually away in the form of a concentrated
+solution; thus constantly exposing the fresh surface of the metal, which
+renders the reaction continuous. The price of the element is lower than
+would be expected at first sight from the employment of so expensive a
+metal. The present cost of sodium is 10 frs. per kilogramme; but M.
+Jablochkoff thinks that on the large scale the metal might be obtained at
+a very low figure. The elements are grouped in sets of ten, hung upon rods
+in such a manner that the solution as formed may drain off. Such a battery
+continues in action as long as the air contains moisture; the only means
+of stopping it is to shut it up in an air-tight case. The electro-motive
+force depends on the degree of humidity in the air, and also upon the
+temperature.
+
+       *       *       *       *       *
+
+ANALYSIS OF PERFUMED SCOURING PASTES.--The analysis of No. 1 resulted in
+water and traces of myrbane oil, 3.66 per cent.; fatty acid, melting at
+104° F., 54.18 per cent.; iron peroxide, 10.11 per cent.; silicic acid,
+14.48 per cent.; alumina, 17.31 per cent.; lime and magnesia, traces. The
+iron peroxide is partly soluble in hydrochloric acid, the alumina entirely
+so as silicate. The scouring paste, therefore, is composed of 54 per cent.
+fatty (palm oil) acid, 10 per cent. jeweler's rouge, 32 per cent.
+pumice-stone powder.
+
+       *       *       *       *       *
+
+
+
+
+SOUND SIGNALS.
+
+
+In Appleton's "Annual Cyclopædia" for 1883, Mr. Arnold B. Johnson, Chief
+Clerk of the Lighthouse Board, contributes a mass of very interesting
+information, under the above title. His descriptions of the most approved
+inventions relating thereto are interesting, and we make the following
+extracts:
+
+The sound signals generally used to guide mariners, especially during
+fogs, are, with certain modifications, sirens, trumpets, steam-whistles,
+bell-boats, bell-buoys, whistling buoys, bells struck by machinery,
+cannons fired by powder or gun cotton, rockets, and gongs.
+
+_Gongs._--Gongs are somewhat used on lightships, especially in British
+waters. They are intended for use at close quarters. Leonce Reynaud, of
+the French lighthouse service, has given their mean effective range as
+barely 550 yards. They are of most use in harbors, short channels, and
+like places, where a long range would be unnecessary. They have been used
+but little in United States waters. The term "effective range" is used
+here to signify the actual distance at which, under the most unfavorable
+circumstances, a signal can generally be heard on board of a paddle-wheel
+steamer in a heavy sea-way.
+
+_Guns._--The use of guns is not so great as it once was. Instances are on
+record in which they were quite serviceable. Admiral Sir A. Milne said he
+had often gone into Halifax harbor, in a dense fog like a wall, by the
+sound of the Sambro fog gun. But in the experiments made by the Trinity
+House off Dungeness in January, 1864, in calm weather, the report of an
+eighteen-pounder, with three pounds of powder, was faint at four miles.
+Still, in the Trinity House experiments of 1865, made in light weather
+with a light gun, the report was clearly heard seven miles away. Dr.
+Gladstone records great variability in the range of gun-sound in the
+Holyhead experiments. Prof. Henry says that a twenty-four-pounder was used
+at Point Boneta, San Francisco Bay, Cal., in 1856-57, and that, by the
+help of it alone, vessels came into the harbor during the fog at night as
+well as in the day, which otherwise could not have entered. The gun was
+fired every half hour, night and day, during foggy and thick weather in
+the first year, except for a time when powder was lacking. During the
+second year there were 1,582 discharges. It was finally superseded by a
+bell-boat, which in its turn was after a time replaced by a siren. A gun
+was also used at West Quoddy Head, Maine. It was a carronade, five feet
+long, with a bore of five and one-quarter inches, charged with four pounds
+of powder. The gun was fired on foggy days when the Boston steamer was
+approaching the lighthouse from St. Johns, and the firing was begun when
+the steamer's whistle was heard, often when she was six miles away, and
+was kept up as fast as the gun could be loaded, until the steamer answered
+with its whistle.
+
+The report of the gun was heard from two to six miles. "This signal was
+abandoned," Prof. Henry says, "because of the danger attending its use,
+the length of intervals between successive explosions, and the brief
+duration of the sound, which renders it difficult to determine its
+direction with accuracy." In 1872 there were three fog guns on the English
+coast, iron eighteen-pounders, carrying a three pound charge of powder,
+which were fired at intervals of fifteen minutes in two places, and of
+twenty minutes in the other. The average duration of fog at these stations
+was said to be about six hours, and as it not unfrequently lasted twenty
+hours, each gun required two gunners, who had to undergo severe labor, and
+the risk of remissness and irregularity was considerable. In 1881 the
+interval between charges was reduced to ten minutes.
+
+The Trinity House, in its experiments at South Foreland, found that the
+short twenty-four pound howitzer gave a better sound than the long
+eighteen-pounder. Tyndall, who had charge of the experiments, sums up as
+to the use of the guns as fog-signals by saying: "The duration of the
+sound is so short that, unless the observer is prepared beforehand, the
+sound, through lack of attention rather than through its own
+powerlessness, is liable to be unheard. Its liability to be quenched by
+local sound is so great that it is sometimes obliterated by a puff of wind
+taking possession of the ears at the time of its arrival. Its liability to
+be quenched by an opposing wind, so as to be practically useless at a very
+short distance to windward, is very remarkable.... Still, notwithstanding
+these drawbacks, I think the gun is entitled to rank as a first-class
+signal."
+
+The minute gun at sea is known the world over as a signal of distress. The
+English lightships fire guns to attract the attention of the lifeboat crew
+when shipwrecks take place in sight of the ships, but out of sight of the
+boats; and guns are used as signals of approaching floods at freshet times
+in various countries.
+
+_Rockets._--As a signal in rock lighthouses, where it would be impossible
+to mount large pieces of apparatus, the use of a gun-cotton rocket has
+been suggested by Sir Richard Collinson, deputy-master of the Trinity
+House. A charge of gun-cotton is inclosed in the head of a rocket, which
+is projected to the height of perhaps 1,000 feet, when the cotton is
+exploded, and the sound shed in all directions. Comparative experiments
+with the howitzer and rocket showed that the howitzer was beaten by a
+rocket containing twelve ounces, eight ounces, and even four ounces of
+gun-cotton. Large charges do not show themselves so superior to small
+charges as might be expected. Some of the rockets were heard at a distance
+of twenty-five miles. Tyndall proposes to call it the Collinson rocket,
+and suggests that it might be used in lighthouses and lightships as a
+signal by naval vessels.
+
+_Bells._--Bells are in use at every United States lightstation, and at
+many they are run by machinery actuated by clock-work, made by Mr.
+Stevens, of Boston, who, at the suggestion of the Lighthouse Board, has
+introduced an escapement arrangement moved by a small weight, while a
+larger weight operates the machinery which strikes the bell. These bells
+weigh from 300 to 3,000 pounds. There are about 125 in use on the coasts
+of the United States. Experiments made by the engineers of the French
+Lighthouse Establishment, in 1861-62, showed that the range of bell-sounds
+can be increased with the rapidity of the bell-strokes, and that the
+relative distances for 15, 25, and 60 bell-strokes a minute were in the
+ratio of 1, 1-14/100, and 1-29/100. The French also, with a hemispherical
+iron reflector backed with Portland cement, increased the bell range in
+the ratio of 147 to 100 over a horizontal arc of 60°, beyond which its
+effect gradually diminished. The actual effective range of the bell sound,
+whatever the bell size, is comparatively short, and, like the gong, it is
+used only where it needs to be heard for short distances. Mr. Cunningham,
+Secretary of the Scottish Lighthouse Establishment, in a paper on fog
+signals, read in February, 1863, says the bell at Howth, weighing 2¼ tons,
+struck four times a minute by a 60 pound hammer falling ten inches, has
+been heard only one mile to windward against a light breeze during fog;
+and that a similar bell at Kingston, struck eight times a minute, had been
+so heard three miles away as to enable the steamer to make her harbor from
+that distance. Mr. Beaseley, C.E., in a lecture on coast-fog signals, May
+24, 1872, speaks of these bells as unusually large, saying that they and
+the one at Ballycottin are the largest on their coasts, the only others
+which compare with them being those at Stark Point and South Stack, which
+weigh 31¾ cwt. and 41½ cwt. respectively. Cunningham, speaking of the
+fog-bells at Bell Rock and Skerryvore lighthouses, says he doubts if
+either bell has been the means of saving a single vessel from wreck during
+fog, and he does not recall an instance of a vessel reporting that she was
+warned to put about in the fog, or that she ascertained her position in
+any respect by hearing the sound of the bell in either place. Gen. Duane,
+U.S.A., says a bell, whether operated by hand or machinery, cannot be
+considered an efficient fog signal on the sea-coast. In calm weather it
+cannot be heard half the time at a greater distance than one mile, while
+in rough weather the noise of the surf will drown its sound to seaward
+altogether. The use of bells is required, by the International Code, on
+ships of all nations, at regular intervals during fog. But Turkish ships
+are allowed to substitute the gong or gun, as the use of bells is
+forbidden to the followers of Mohammed.
+
+[Illustration: FIG. 1.--COURTENAY'S WHISTLING BUOY.]
+
+_Whistling Buoys._--The whistling buoy now in use was patented by Mr. J.M.
+Courtenay, of New York. It consists of an iron pear-shaped bulb, 12 feet
+across at its widest part, and floating 12 feet out of water. Inside the
+bulb is a tube 33 inches across, extending from the top through the bottom
+to a depth of 32 feet, into water free from wave motion. The tube is open
+at its lower end, but projects, air-tight, through the top of the bulb,
+and is closed with a plate having in it three holes, two for letting the
+air into the tube, and one between the others for letting the air out to
+work the 10-inch locomotive whistle with which it is surmounted. These
+holes are connected with three pipes which lead down to near the water
+level, where they pass through a diaphragm which divides the outer
+cylinder into two parts. The great bulb which buoys up the whole mass
+rises and falls with the motion of the waves, carrying the tube up and
+down with it, thus establishing a piston-and-cylinder movement, the water
+in the tube acting as an immovable piston, while the tube itself acts as a
+moving cylinder. Thus the air admitted through valves, as the buoy rises
+on the wave, into that part of the bulb which is above water, is
+compressed, and as the buoy falls with the wave, it is further compressed
+and forced through a 2½ inch pipe which at its apex connects with the
+whistle. The dimensions of the whistling buoy have recently been much
+diminished without detracting materially from the volume of sound it
+produces. It is now made of four sizes. The smallest in our waters has a
+bulb 6 feet in diameter and a tube 10 feet in length, and weighs but 2,000
+pounds. The largest and oldest whistling buoy has a 12-foot bulb, a tube
+32 feet long, and weighs 12,000 pounds.
+
+There are now 34 of these whistling buoys on the coast of the United
+States, which have cost, with their appurtenances, about $1,200 each. It
+is a curious fact that, in proportion as they are useful to the mariner,
+they are obnoxious to the house dweller within earshot of them, and that
+the Lighthouse Board has to weigh the petitions and remonstrances before
+setting these buoys off inhabited coasts. They can at times be heard 15
+miles, and emit an inexpressibly mournful and saddening sound.
+
+The inspector of the First Lighthouse District, Commander Picking,
+established a series of observations at all the light stations in the
+neighborhood of the buoys, giving the time of hearing it, the direction of
+the wind, and the state of the sea, from which it appears that in January,
+1878, one of these buoys was heard every day at a station 1-1/8 miles
+distant, every day but two at one 2¼ miles distant, 14 times at one 7½
+miles distant, and 4 times at one 8½ miles distant. It is heard by the
+pilots of the New York and Boston steamers at a distance of one-fifth of a
+mile to 5 miles, and has been frequently heard at a distance of 9 miles,
+and even, under specially favorable circumstances, 15 miles.
+
+The whistling buoy is also used to some extent in British, French, and
+German waters, with good results. The latest use to which it has been put
+in this country has been to place it off the shoals of Cape Hatteras,
+where a light ship was wanted but could not live, and where it does
+almost as well as a light ship would have done. It is well suited for such
+broken and turbulent waters, as the rougher the sea the louder its sound.
+
+[Illustration: FIG. 2.--BROWN'S BELL BUOY.]
+
+_Bell-Buoys._--The bell-boat, which is at most a clumsy contrivance,
+liable to be upset in heavy weather, costly to build, hard to handle, and
+difficult to keep in repair, has been superseded by the Brown bell-buoy,
+which was invented by the officer of the lighthouse establishment whose
+name it bears. The bell is mounted on the bottom section of an iron buoy 6
+feet 6 inches across, which is decked over and fitted with a framework of
+3-inch angle-iron 9 feet high, to which a 300-pound bell is rigidly
+attached. A radial grooved iron plate is made fast to the frame under the
+bell and close to it, on which is laid a free cannon-ball. As the buoy
+rolls on the sea, this ball rolls on the plate, striking some side of the
+bell at each motion with such force as to cause it to toll. Like the
+whistling-buoy, the bell-buoy sounds the loudest when the sea is the
+roughest, but the bell-buoy is adapted to shoal water, where the
+whistling-buoy could not ride; and, if there is any motion to the sea, the
+bell-buoy will make some sound. Hence the whistling-buoy is used in
+roadsteads and the open sea, while the bell-buoy is preferred in harbors,
+rivers, and the like, where the sound-range needed is shorter, and
+smoother water usually obtains. In July, 1883, there were 24 of these
+bell-buoys in United States waters. They cost, with their fitments and
+moorings, about $1,000 each.
+
+_Locomotive-Whistles._--It appears from the evidence given in 1845, before
+the select committee raised by the English House of Commons, that the use
+of the locomotive-whistle as a fog-signal was first suggested by Mr. A.
+Gordon, C.E., who proposed to use air or steam for sounding it, and to
+place it in the focus of a reflector, or a group of reflectors, to
+concentrate its sounds into a powerful phonic beam. It was his idea that
+the sharpness or shrillness of the whistle constituted its chief value.
+And it is conceded that Mr. C.L. Daboll, under the direction of Prof.
+Henry, and at the instance of the United States Lighthouse Board, first
+practically used it as a fog-signal by erecting one for use at Beaver Tail
+Point, in Narragansett Bay. The sounding of the whistle is well described
+by Price-Edwards, a noted English lighthouse engineer, "as caused by the
+vibration of the column of air contained within the bell or dome, the
+vibration being set up by the impact of a current of steam or air at a
+high pressure." It is probable that the metal of the bell is likewise set
+in vibration, and gives to the sound its timbre or quality. It is noted
+that the energy so excited expends its chief force in the immediate
+vicinity of its source, and may be regarded, therefore, as to some extent
+wasted. The sound of the whistle, moreover, is diffused equally on all
+sides. These characteristics to some extent explain the impotency of the
+sound to penetrate to great distances. Difference in pitch is obtained by
+altering the distance between the steam orifice and the rim of the drum.
+When brought close to each other, say within half an inch, the sound
+produced is very shrill, but it becomes deeper as the space between the
+rim and the steam or air orifice is increased.
+
+Prof. Henry says the sound of the whistle is distributed horizontally. It
+is, however, much stronger in the plane containing the lower edge of the
+bell than on either side of this plane. Thus, if the whistle is standing
+upright in the ordinary position, its sound is more distinct in a
+horizontal plane passing through the whistle than above it or below it.
+
+The steam fog-whistle is the same instrument ordinarily used on steamboats
+and locomotives. It is from 6 to 18 inches in diameter, and is operated by
+steam under a pressure of from 50 to 100 pounds. An engine takes its steam
+from the same boiler, and by an automatic arrangement shuts off and turns
+on the steam by opening and closing its valves at determined times. The
+machinery is simple, the piston-pressure is light, and the engine requires
+no more skilled attention than does an ordinary station-engine.
+
+"The experiments made by the Trinity House in 1873-74 seem to show,"
+Price-Edwards says, "that the sound of the most powerful whistle, whether
+blown by steam or hot air, was generally inferior to the sound yielded by
+other instruments," and consequently no steps were taken to extend their
+use in Great Britain, where several were then in operation. In Canadian
+waters, however, a better result seems to have been obtained, as the
+Deputy Minister of Marine and Fisheries, in his annual report for 1872,
+summarizes the action of the whistles in use there, from which it appears
+that they have been heard at distances varying with their diameter from 3
+to 25 miles.
+
+The result of the experiments made by Prof. Henry and Gen. Duane for the
+United States Lighthouse Board, reported in 1874, goes to show that the
+steam-whistle could be heard far enough for practical uses in many
+positions. Prof. Henry found that he could hear a 6-inch whistle 7¼ miles
+with a feeble opposing wind. Gen. Duane heard the 10-inch whistle at Cape
+Elizabeth at his house in Portland, Maine, nine miles distant, whenever it
+was in operation. He heard it best during a heavy northeast snow storm,
+the wind blowing then directly from him, and toward the source of the
+sound. Gen. Duane also reported that "there are six fog-signals on the
+coast of Maine; these have frequently been heard at the distance of twenty
+miles," ... which distance he gives as the extreme limit of the
+twelve-inch steam-whistle.
+
+_Trumpets._--The Daboll trumpet was invented by Mr. C.L. Daboll, of
+Connecticut, who was experimenting to meet the announced wants of the
+United States Lighthouse Board. The largest consists of a huge trumpet
+seventeen feet long, with a throat three and one-half inches in diameter,
+and a flaring mouth thirty-eight inches across. In the trumpet is a
+resounding cavity, and a tongue-like steel reed ten inches long, two and
+three-quarter inches wide, one inch thick at its fixed end, and half that
+at its free end. Air is condensed in a reservoir and driven through the
+trumpet by hot air or steam machinery at a pressure of from fifteen to
+twenty pounds, and is capable of making a shriek which can be heard at a
+great distance for a certain number of seconds each minute, by about
+one-quarter of the power expended in the case of the whistle. In all his
+experiments against and at right angles and at other angles to the wind,
+the trumpet stood first and the whistle came next in power. In the trial
+of the relative power of various instruments made by Gen. Duane in 1874,
+the twelve-inch whistle was reported as exceeding the first-class Daboll
+trumpet. Beaseley reports that the trumpet has done good work at various
+British stations, making itself heard from five to ten miles. The engineer
+in charge of the lighthouses of Canada says: "The expense for repairs, and
+the frequent stoppages to make these repairs during the four years they
+continued in use, made them [the trumpets] expensive and unreliable. The
+frequent stoppages during foggy weather made them sources of danger
+instead of aids to navigation. The sound of these trumpets has
+deteriorated during the last year or so." Gen. Duane, reporting as to his
+experiments in 1881, says: "The Daboll trumpet, operated by a caloric
+engine, should only be employed in exceptional cases, such as at stations
+where no water can be procured, and where from the proximity of other
+signals it may be necessary to vary the nature of the sound." Thus it
+would seem that the Daboll trumpet is an exceptionally fine instrument,
+producing a sound of great penetration and of sufficient power for
+ordinary practical use, but that to be kept going it requires skillful
+management and constant care.
+
+_The Siren._--The siren was adapted from the instrument invented by
+Cagniard de la Tour, by A. and F. Brown, of the New York City Progress
+Works, under the guidance of Prof. Henry, at the instance and for the use
+of the United States Lighthouse Establishment, which also adopted it for
+use as a fog-signal. The siren of the first class consists of a huge
+trumpet, somewhat of the size and shape used by Daboll, with a wide mouth
+and a narrow throat, and is sounded by driving compressed air or steam
+through a disk placed in its throat. In this disk are twelve radial slits;
+back of the fixed disk is a revolving plate, containing as many similar
+openings. The plate is rotated 2,400 times each minute, and each
+revolution causes the escape and interruption of twelve jets of air or
+steam through the openings in the disk and rotating plate. In this way
+28,800 vibrations are given during each minute that the machine is
+operated; and, as the vibrations are taken up by the trumpet, an intense
+beam of sound is projected from it. The siren is operated under a pressure
+of seventy-two pounds of steam, and can be heard, under favorable
+circumstances, from twenty to thirty miles. "Its density, quality, pitch,
+and penetration render it dominant over such other noises after all other
+signal-sounds have succumbed." It is made of various sizes or classes, the
+number of slits in its throat-disk diminishing with its size. The
+dimensions given above are those of the largest. [See engraving on page
+448, "Annual Cyclopædia" for 1880.]
+
+The experiments made by Gen. Duane with these three machines show that the
+siren can be, all other things being equal, heard the farthest, the
+steam-whistle stands next to the siren, and the trumpet comes next to the
+whistle. The machine which makes the most noise consumes the most fuel.
+From the average of the tests it appears that the power of the first-class
+siren, the twelve-inch whistle, and first-class Daboll trumpet are thus
+expressed: siren nine, whistle seven, trumpet four; and their relative
+expenditure of fuel thus: siren nine, whistle three, trumpet one.
+
+Sound-signals constitute so large a factor in the safety of the navigator,
+that the scientists attached to the lighthouse establishments of the
+various countries have given much attention to their production and
+perfection, notably Tyndall in England and Henry in this country. The
+success of the United States has been such that other countries have sent
+commissions here to study our system. That sent by England in 1872, of
+which Sir Frederick Arrow was chairman, and Captain Webb, R.N., recorder,
+reported so favorably on it that since then "twenty-two sirens have been
+placed at the most salient lighthouses on the British coasts, and sixteen
+on lightships moored in position where a guiding signal is of the greatest
+service to passing navigation."
+
+The trumpet, siren, and whistle are capable of such arrangement that the
+length of blast and interval, and the succession of alternation, are such
+as to identify the location of each, so that the mariner can determine his
+position by the sounds.
+
+In this country there were in operation in July, 1883, sixty-six
+fog-signals operated by steam or hot air, and the number is to be
+increased in answer to the urgent demands of commerce.
+
+_Use of Natural Orifices._--There are, in various parts of the world,
+several sound-signals made by utilizing natural orifices in cliffs through
+which the waves drive the air with such force and velocity as to produce
+the sound required. One of the most noted is that on one of the Farallon
+Islands, forty miles off the harbor of San Francisco, which was
+constructed by Gen. Hartmann Bache, of the United States Engineers, in
+1858-59, and of which the following is his own description:
+
+"Advantage was taken of the presence of the working party on the island to
+make the experiment, long since contemplated, of attaching a whistle as a
+fog-signal to the orifice of a subterranean passage opening out upon the
+ocean, through which the air is violently driven by the beating of the
+waves. The first attempt failed, the masonry raised upon the rock to which
+it was attached being blown up by the great violence of the wind-current.
+A modified plan with a safety-valve attached was then adopted, which it is
+hoped will prove permanent. ... The nature of this work called for 1,000
+bricks and four barrels of cement."
+
+Prof. Henry says of this:
+
+"On the apex of this hole he erected a chimney which terminated in a tube
+surmounted by a locomotive-whistle. By this arrangement a loud sound was
+produced as often as the wave entered the mouth of the indentation. The
+penetrating power of the sound from this arrangement would not be great if
+it depended merely on the hydrostatic pressure of the waves, since this
+under favorable circumstances would not be more than that of a column of
+water twenty feet high, giving a pressure of about ten pounds to the
+square inch. The effect, however, of the percussion might add considerably
+to this, though the latter would be confined in effect to a single
+instance. In regard to the practical result from this arrangement, which
+was continued in operation for several years, it was found not to obviate
+the necessity of producing sounds of greater power. It is, however,
+founded on an ingenious idea, and may be susceptible of application in
+other cases."
+
+There is now a first-class siren in duplicate at this place.
+
+The sixty-six steam fog-signals in the waters of the United States have
+been established at a cost of more than $500,000, and are maintained at a
+yearly expense of about $100,000. The erection of each of these signals
+was authorized by Congress in an act making special appropriations for its
+establishment, and Congress was in each instance moved thereto by the
+pressure of public opinion, applied usually through the member of Congress
+representing the particular district in which the signal was to be
+located. And this pressure was occasioned by the fact that mariners have
+come to believe that they could be guided by sound as certainly as by
+sight. The custom of the mariner in coming to this coast from beyond the
+seas is to run his ship so that on arrival, if after dark, he shall see
+the proper coast-light in fair weather, and, if in thick weather, that he
+shall hear fog-signal, and, taking that as a point of departure, to feel
+his way from the coast-light to the harbor-light, or from the fog-signal
+on the coast to the fog-signal in the harbor, and thence to his anchorage
+or his wharf. And the custom of the coaster or the sound-steamer is
+somewhat similar.
+
+       *       *       *       *       *
+
+
+
+
+TREVITHICK'S ENGINE AT CREWE.
+
+
+The old high-pressure engine of Richard Trevithick, which, thanks to Mr.
+Webb, has been rescued from a scrap heap in South Wales, and re-erected at
+the Crewe Works. We give engravings of this engine, which have been
+prepared from photographs kindly furnished to us by Mr. Webb, and which
+will clearly show its design.
+
+[Illustration: TREVITHICK'S HIGH PRESSURE ENGINE AT CREWE.]
+
+The boiler bears a name-plate with the words "No. 14, Hazeldine and Co.,
+Bridgnorth," and it is evidently one of the patterns which Trevithick was
+having made by Hazeldine and Co., about the year 1804. The shell of the
+boiler is of cast iron, and the cylinder, which is vertical, is cast in
+one with it, the back end of the boiler and the barrel being in one piece
+as shown. At the front end the barrel has a flange by means of which it is
+bolted to the front plate, the plate having attached to it the furnace and
+return flue, which are of wrought iron. The front plate has also cast on
+it a manhole mouthpiece to which the manhole cover is bolted. In the case
+of the engine at Crewe, the chimney, firehole door, and front of flue had
+to be renewed by Mr. Webb, these parts having been broken up before the
+engine came into his possession.
+
+The piston rod is attached to a long cast-iron crosshead, from which two
+bent connecting rods extend downward, the one to a crank, and the other to
+a crank-pin inserted in the flywheel. The connecting-rods now on this
+engine were supplied by Mr. Webb, the original ones--which they have been
+made to resemble as closely as possible--having been broken up. In the
+Crewe engine as it now exists it is not quite clear how the power was
+taken off from the crankshaft, but from the particulars of similar engines
+recorded in the "Life of Richard Trevithick," it appears that a small spur
+pinion was in some cases fixed on the crankshaft, and in others a
+spurwheel, with a crank-pin inserted in it, took the place of the crank at
+the end of the shaft opposite to that carrying the flywheel. In the Crewe
+engine the flywheel, it will be noticed, is provided with a balanceweight.
+
+The admission of the steam to and its release from the cylinder is
+effected by a four-way cock provided with a lever, which is actuated by a
+tappet rod attached to the crosshead, as seen on the back view of the
+engine. To the crosshead is also coupled a lever having its fulcrum on a
+bracket attached to the boiler; this lever serving to work the feed pump.
+Unfortunately the original pump of the Crewe engine was smashed, but Mr.
+Webb has fitted one up to show the arrangement. A notable feature in the
+engine is that it is provided with a feed heater through which the water
+is forced by the pump on its way to the boiler. The heater consists of a
+cast-iron pipe through which passes the exhaust pipe leading from the
+cylinder to the chimney, the water circulating through the annular space
+between the two pipes.
+
+Altogether the Trevithick engine at Crewe is a relic of the very highest
+interest, and it is most fortunate that it has come into Mr. Webb's hands
+and has thus been rescued from destruction. No one, bearing in mind the
+date at which it was built, can examine this engine without having an
+increased respect for the talents of Richard Trevithick, a man to whom we
+owe so much and whose labors have as yet met with such scant
+recognition.--_Engineering._
+
+       *       *       *       *       *
+
+
+
+
+[Continued from SCIENTIFIC AMERICAN SUPPLEMENT, No. 451, page 7192.]
+
+PLANETARY WHEEL TRAINS.
+
+By Prof. C.W. MacCORD, Sc. D.
+
+IV.
+
+
+The arrangement of planetary wheels which has been applied in practice to
+the greatest extent and to the most purposes, is probably that in which
+the axial motions of the train are derived from a fixed sun wheel.
+Numerous examples of such trains are met with in the differential gearing
+of hoisting machines, in portable horse-powers, etc. The action of these
+mechanisms has already been fully discussed; it may be remarked in
+addition that unless the speed be very moderate, it is found advantageous
+to balance the weights and divide the pressures by extending the train arm
+and placing the planet-wheels in equal pairs diametrically opposite each
+other, as, for instance, in Bogardus' horse power, Fig. 31.
+
+[Illustration: PLANETARY WHEEL TRAINS.]
+
+In trains of this description, the velocity ratio is invariable; which for
+the above-mentioned objects it should be. But the use of a planetary
+combination enables us to cause the motions of two independent trains to
+converge, and unite in producing a single resultant rotation. This may be
+done in two ways; each of the two independent trains may drive one
+sun-wheel, thus determining the motion of the train-arm; or, the train-arm
+may be driven by one of them, and the first sun-wheel by the other; then
+the motion of the second sun-wheel is the resultant. Under these
+circumstances the ratio of the resultant velocity to that of either
+independent train is not invariable, since it may be affected by a change
+in the velocity of the other one. To illustrate our meaning, we give two
+examples of arrangements of this nature. The first is Robinson's
+rope-making machine, Fig. 32. The bobbins upon which the strands composing
+the rope are wound turn freely in bearings in the frames, G, G, and these
+frames turn in bearings in the disk, H, and the three-armed frame or
+spider, K, both of which are secured to the central shaft, S. Each
+bobbin-frame is provided with a pinion, _a_, and these three pinions
+engage with the annular wheel, A. This wheel has no shaft, but is carried
+and kept in position by three pairs of rollers, as shown, so that its axis
+of rotation is the same as that of the shaft, S; and it is toothed
+externally as well as internally. The strands pass through the hollow
+axes of the pinions, and thence each to its own opening through the
+laying-top, T, fixed upon S, which completes the operation of twisting
+them into a rope. The annular wheel, A, it will be perceived, may be
+driven by a pinion, E, engaging with its external teeth, at a rate of
+speed different from that of the central shaft; and by varying the speed
+of that pinion, the velocity of the wheel, A, may be changed without
+affecting the velocity of S.
+
+It is true that in making a certain kind of rope, the velocity ratio of A
+and S must remain constant, in order that the strands may be equally
+twisted throughout; but if for another kind of rope a different degree of
+twist is wanted, the velocity of the pinion, E, may be altered by means of
+change-wheels, and thus the same machine may be used for manufacturing
+many different sorts.
+
+The second combination of this kind was devised by the writer as a
+"tell-tale" for showing whether the engines driving a pair of twin
+screw-propellers were going at the same rate. In Fig. 33, an index, P, is
+carried by the wheel, F: the wheel, A, is loose upon the shaft of the
+train-arm, which latter is driven by the wheel, E. The wheels, F and _f_,
+are of the same size, but _a_ is twice as large as A; if then A be driven
+by one engine, and E by the other, at the same rate but in the opposite
+direction, the index will remain stationary, whatever the absolute
+velocities. But if either engine go faster than the other, the index will
+turn to the right or the left accordingly. The same object may also be
+accomplished as shown in Fig. 34, the index being carried by the
+train-arm. It makes no difference what the actual value of the ratio A/_a_
+may be, but it must be equal to F/_f_: under which condition it is evident
+that if A and F be driven contrary ways at equal speeds, small or great,
+the train-arm will remain at rest; but any inequality will cause the index
+to turn.
+
+In some cases, particularly when annular wheels are used, the train-arm
+may become very short, so that it may be impossible to mount the
+planet-wheel in the manner thus far represented, upon a pin carried by a
+crank. This difficulty may be surmounted as shown in Fig. 35, which
+illustrates an arrangement originally forming a part of Nelson's steam
+steering gear. The Internal pinions, _a_, _f_, are but little smaller than
+the annular wheels, A, F, and are hung upon an eccentric E formed in one
+solid piece with the driving shaft, D.
+
+The action of a complete epicyclic train involves virtually and always the
+action of two suns and two planets; but it has already been shown that the
+two planets may merge into one piece, as in Fig. 10, where the
+planet-wheel gears externally with one sun-wheel, and internally with the
+other.
+
+But the train may be reduced still further, and yet retain the essential
+character of completeness in the same sense, though composed actually of
+but two toothed wheels. An instance of this is shown in Fig. 36, the
+annular planet being hung upon and carried by the pins of three cranks,
+_c_, _c_, _c_, which are all equal and parallel to the virtual train-arm,
+T. These cranks turning about fixed axes, communicate to _f_ a motion of
+circular translation, which is the resultant of a revolution, _v'_, about
+the axis of F in one direction, and a rotation, _v_, at the same rate in
+the opposite direction about its own axis, as has been already explained.
+The cranks then supply the place of a fixed sun-wheel and a planet of
+equal size, with an intermediate idler for reversing the, direction of the
+rotation of the planet; and the velocity of F is
+
+V'= v'(1 - f/F).
+
+A modification of this train better suited for practical use is shown in
+Fig. 37, in which the sun-wheel, instead of the planet, is annular, and
+the latter is carried by the two eccentrics, E, E, whose throw is equal to
+the difference between the diameters of the two pitch circles; these
+eccentrics must, of course, be driven in the same direction and at equal
+speeds, like the cranks in Fig. 36.
+
+[Illustration: PLANETARY WHEEL TRAINS.]
+
+A curious arrangement of pin-gearing is shown in Fig. 38: in this case the
+diameter of the pinion is half that of the annular wheel, and the latter
+being the driver, the elementary hypocycloidal faces of its teeth are
+diameters of its pitch circle; the derived working tooth-outlines for pins
+of sensible diameter are parallels to these diameters, of which fact
+advantage is taken to make the pins turn in blocks which slide in straight
+slots as shown. The formula is the same as that for Fig. 36, viz.:
+
+V' = v'(1 - f/F),
+
+which, since f = 2F, reduces to V' = -v'.
+
+Of the same general nature is the combination known as the "Epicycloidal
+Multiplying Gear" of Elihu Galloway, represented in Fig. 39. Upon
+examination it will be seen, although we are not aware that attention has
+previously been called to the fact, that this differs from the ordinary
+forms of "pin gearing" only in this particular, viz., that the elementary
+tooth of the driver consists of a complete branch, instead of a
+comparatively small part of the hypocycloid traced by rolling the smaller
+pitch-circle within the larger. It is self-evident that the hypocycloid
+must return into itself at the point of beginning, without crossing: each
+branch, then, must subtend an aliquot part of the circumference, and can
+be traced also by another and a smaller describing circle, whose diameter
+therefore must be an aliquot part of the diameter of the outer
+pitch-circle; and since this last must be equal to the sum of the
+diameters of the two describing circles, it follows that the radii of the
+pitch circles must be to each other in the ratio of two successive
+integers; and this is also the ratio of the number of pins to that of the
+epicycloidal branches.
+
+Thus in Fig. 39, the diameters of the two pitch circles are to each other
+as 4 to 5; the hypocycloid has 5 branches, and 4 pins are used. These pins
+must in practice have a sensible diameter, and in order to reduce the
+friction this diameter is made large, and the pins themselves are in the
+form of rollers. The original hypocycloid is shown in dotted line, the
+working curve being at a constant normal distance from it equal to the
+radius of the roller; this forms a sort of frame or yoke, which is hung
+upon cranks as in Figs. 36 and 38. The expression for the velocity ratio
+is the same as in the preceding case:
+
+V¹ = v'(1 - f/F); which in Fig. 39 gives
+
+V¹ = v'(1 - 5/4)= -¼v':
+
+the planet wheel, or epicycloidal yoke, then, has the higher speed, so
+that if it be desired to "gear up," and drive the propeller faster than
+the engine goes (and this, we believe, was the purpose of the inventor),
+the pin-wheel must be made the driver; which is the reverse of
+advantageous in respect to the relative amounts of approaching and
+receding action.
+
+In Figs. 40 and 41 are given the skeletons of Galloway's device for ratios
+of 3:4 and 2:3 respectively, the former having four branches and three
+pins, the latter three branches and two pins. Following the analogy, it
+would seem that the next step should be to employ two branches with only
+one pin; but the rectilinear hypocycloid of Fig. 38 is a complete
+diameter, and the second branch is identical with the first; the straight
+tooth, then, could theoretically drive the pin half way round, but upon
+its reaching the center of the outer wheel, the driving action would
+cease: this renders it necessary to employ two pins and two slots, but it
+is not essential that the latter should be perpendicular to each other.
+
+In these last arrangements, the forms of the parts are so different from
+those of ordinary wheels, that the true nature of the combinations is at
+least partially disguised. But it may be still more completely hidden, as
+for instance in the common elliptic trammel, Fig. 42. The slotted cross is
+here fixed, and the pins, R and P, sliding respectively in the vertical
+and horizontal lines, control the motion of the bar which carries the
+pencil, S. At first glance there would seem to be nothing here resembling
+wheel works. But if we describe a circle upon R P as a diameter, its
+circumference will always pass through C, because R C P is a right angle,
+and the instantaneous axis of the bar being at the intersection O of a
+vertical line through P, with a horizontal line through R, will also lie
+upon this circumference. Again, since O is diametrically opposite to C, we
+have C O = R P, whence a circle about center C with radius R P will also
+pass through O, which therefore is the point of contact of these two
+circles. It will now be seen that the motion of the bar is the same as
+though carried by the inner circle while rolling within the outer one, the
+latter being fixed; the points P and R describing the diameters L M and K
+N, the point D a circle, and S an ellipse; C D being the train-arm. The
+distance R P being always the diameter of one circle and the radius of the
+other, the sizes of the wheels can be in effect varied by altering that
+distance.
+
+Thus we see that this combination is virtually the same in its action as
+the one shown in Fig. 43, known as Suardi's Geometrical Pen. In this
+particular case the diameter of _a_ is half of that of A; these wheels are
+connected by the idler, E, which merely reverses the direction without
+affecting the velocity of _a's_ rotation. The working train arm is jointed
+so as to pivot about the axis of E, and may be clamped at any angle within
+its range, thus changing the length of the virtual train arm, C D. The bar
+being fixed to _a_, then, moves as though carried by the wheel, _a¹_,
+rolling within A¹; the radius of _a¹_ being C D, and that of A¹ twice as
+great.
+
+In either instrument, the semi-major axis C X is equal to S R, and the
+semi-minor axis to S P.
+
+The _ellipse_, then, is described by these arrangements because it is a
+special form of the epitrochoid; and various other epitrochoids may be
+traced with Suardi's pen by substituting other wheels, with different
+numbers of teeth, for a in Fig. 43.
+
+Another disguised planetary arrangement is found in Oldham's coupling,
+Fig. 44. The two sections of shafting, A and B, have each a flange or
+collar forged or keyed upon them; and in each flange is planed a
+transverse groove. A third piece, C, equal in diameter to the flanges, is
+provided on each side with a tongue, fitted to slide in one of the
+grooves, and these tongues are at right angles to each other. The axes of
+A and B must be parallel, but need not coincide; and the result of this
+connection is that the two shafts will turn in the same direction at the
+same rate.
+
+The fact that C in this arrangement is in reality a planetary wheel, will
+be perceived by the aid of the diagram, Fig. 45. Let C D be two pieces
+rotating about fixed parallel axes, each having a groove in which slides
+freely one of the arms, A C, A D, which are rigidly secured to each other
+at right angles.
+
+The point C of the upper arm can at the instant move only in the direction
+C A; and the point D of the lower arm only in the direction A D, at the
+same instant; the instantaneous axis is therefore at the intersection, K,
+of perpendiculars to A C and A D, at the points C and D. C A D K being
+then a rectangle, A K and C D will be two diameters of a circle whose
+center, O, bisects C D; and K will also be the point of contact between
+this circle and another whose center is A, and radius A K = C D. If then
+we extend the arms so as to form the cross, P K, M N, and suppose this to
+be carried by the outer circle, _f_, rolling upon the inner one, F, its
+motion will be the same as that determined by the pieces, C D; and such a
+cross is identical with that formed by the tongues on the coupling-piece,
+C, of Fig. 44.
+
+A O is the virtual train-arm; let the center, A, of the cross move to the
+position B, then since the angles A O B at the center, and A C B in the
+circumference, stand on the same arc, A B, the former is double the
+latter, showing that the cross revolves twice round the center O during
+each rotation of C; and since A C B = A D B, C and D rotate with equal
+velocities, and these rotations and the revolution about O have the same
+direction. While revolving, the cross rotates about its traveling center,
+A, in the opposite direction, the contact between the two circles being
+internal, and at a rate equal to that of the rotations of C and D, because
+the velocities of the axial and the orbital motion are to each other as
+_f_ is to F, that is to say, as 1 is to 2. Since in the course of the
+revolution the points P and K must each coincide with C, and the points M
+and N with D, it follows that each tongue in Fig. 44 must slide in its
+groove a distance equal to twice that between the axes of the shafts.
+
+Another example of a disguised planetary train is shown in Fig. 46. Let C
+be the center about which the train arm, T, revolves, and suppose it
+required that the distant shaft, B, carried by T, shall turn once backward
+for each forward revolution of the arm. E is a fixed eccentric of any
+convenient diameter, in the upper side of which is a pin, D. On the shaft,
+B, is keyed a crank, B G, equal in length to C D; and at any convenient
+point, H, on B C, or its prolongation, another crank, H F, equal also to C
+D, is provided with a bearing in the train-arm. The three crank pins, F,
+D, G, are connected by a rod, like the parallel rod of a locomotive; F D,
+D G, being respectively equal to H C, C B. Then, as the train-arm
+revolves, the three cranks must remain parallel to each other; but C D
+being fixed, the cranks, H F and B G, will remain always parallel to their
+original positions, thus receiving the required motion of circular
+translation.
+
+The result then is the same as though the periphery of E were formed into
+a fixed spurwheel, A, and another, _a_, of the same size, secured on a
+shaft, B, the two being connected by the three equal wheels, L, M, N. It
+need hardly be stated that instead of the eccentric, E, a stationary crank
+similar and equal to B G may be used, should it be found better suited to
+the circumstances of the case.
+
+It is possible also to apply the planetary principle to mechanism composed
+partially of racks; in fact, a rack is merely a wheel of prodigious
+size--the limiting case, just as a right line is a circle of infinite
+radius. A very neat application of this principle is found in Villa's
+Pantograph, of which a full description and illustration was given in
+SCIENTIFIC AMERICAN SUPPLEMENT, No. 424; the racks, moving side by side,
+are the sun-wheels, and the planet-wheels are the pinions, carried by the
+traveling socket, by which the motion of one rack is transmitted to the
+other.
+
+Thus far attention has been called only to combinations of circular
+wheels. In these the velocity ratios are constant, if we except the cases
+in which two independent trains converge, the two sun-wheels, or one of
+them and the train-arm, being driven separately--and even in those, a
+variable motion of the ultimate follower is obtained only by varying the
+speed of one or both drivers. It is not, however, necessary to employ
+circular wheels exclusively or even at all; wheels of other forms are
+capable of acting together in the relation of sun and planet, and in this
+way a varying velocity ratio may be produced even with a fixed sun-wheel
+and a single driver. We have not found, in the works of any previous
+writer, any intimation that noncircular wheels have ever been thus
+combined; and we propose in the following article to illustrate some
+curious results which may be thus obtained.
+
+       *       *       *       *       *
+
+
+
+
+THE FALLACY OF THE PRESENT THEORY OF SOUND.
+
+
+Dr. H.A. Mott recently delivered a lecture before the New York Academy of
+Sciences, in Columbia College, on the Fallacy of the Present Theory of
+Sound.
+
+He commenced his lecture by stating that "the object of science was not to
+find out what we like or what we dislike; the object of science was
+truth." He then said that, as Galileo stated a hypothesis should be judged
+by the weight of facts and the force of mathematical deductions, he
+claimed the theory of sound should be so examined, and not allowed to
+exist as a true theory simply because it is sustained by a long line of
+scientific names; as too many theories had been overthrown to warrant the
+acceptance of any one authority unless they had been thoroughly tested.
+Dr. Mott stated that Dr. Wilford Hall was the first to attack the theory
+of sound and show its fallaciousness, and that many other scientists
+besides himself had agreed with Dr. Hall in his arguments and had advanced
+additional arguments and experiments to establish this fact. Dr. Mott
+first gave a very elaborate and still at the same time condensed statement
+of the current theory of sound as propounded by such men as Helmholtz,
+Tyndall, Lord Rayleigh, Mayer, Rood, Sir Wm. Thomson, and others, and
+closed this section of the paper with the remarks made by Tyndall:
+"Assuredly no question of science ever stood so much in need of revision
+as this of the transmission of sound through the atmosphere. Slowly but
+surely we mastered the question, and the further we advance, the more
+plainly it appeared that our reputed knowledge regarding it was erroneous
+from beginning to end."
+
+Dr. Mott then took up the other side of the question, and treated the same
+under the following heads:
+
+1. Agitation of the air. 2. Mobility of the atmosphere. 3. Resonance. 4.
+Heat and velocity of the supposed sound waves. 5. Decrease in loudness of
+sound. 6. The physical strength of the locust. 7. The barometric theory of
+Sir Wm. Thomson. 8. Elasticity and density of the air. 9. Interference and
+beats. 10. The membrana tympani and the corti arches.
+
+Under the first head Dr. Mott stated that all experiments and photographs
+made to establish the existence of sound waves simply referred to the
+necessary agitation of the air accompanying any disturbance, such as would
+of necessity be produced by a vibrating body, and had nothing to do
+directly with sound. He stated that in the Edison telephone, sound was
+converted directly into electricity without vibrating any diaphragm at
+all, as attested to by Edison himself. Speaking of the mobility of the
+air, he said the particles were free to slip around and not practically be
+pushed at all, and that the greatest distance a steam whistle could affect
+the air would not exceed 30 feet, and the waves would not travel more than
+4 or 5 feet a second, while sound travels 1,120 feet a second. Under heat
+and velocity of sound waves, Dr. Mott stated that Newton found by
+calculating the exact relative density and elasticity of air that sound
+should travel only 916 feet a second, while it was known to travel 1,120
+feet a second.
+
+Laplace, by a heat and cold theory, tried to account for the 174 feet, and
+supposed that in the condensed portion of a sound wave heat was generated,
+and in the rarefied portion cold was produced; the heat augmenting the
+elasticity and therefore the sound waves, and the cold produced
+neutralizing the heat, thus kept the atmosphere at a constant temperature.
+Dr. Mott stated that when Newton first pointed out this discrepancy of 174
+feet, the theory should have been dropped at once, and later on he showed
+the consequences of Laplace's heat and cold theory.
+
+The great argument of the evening, and the one to which he attached the
+most importance, was that all scientists have spoken of the swift movement
+of the tuning fork, while in fact it moved 25,000 times slower than the
+hour hand of a clock and 300,000,000 times slower than any clock pendulum
+ever constructed.
+
+Since a pendulum cannot, according to the high authorities, produce
+sonorous air waves on account of its slow movement, Dr. Mott asks some one
+to enlighten him how a prong of a tuning fork going 300,000,000 times
+slower could be able to produce them. He then showed that there was not
+the slightest similarity between the theoretical sound waves and water
+waves, and still they are spoken of as "precisely similar" and
+"essentially identical," and "move in exactly the same way." Considerable
+merriment was occasioned when Dr. Mott showed what a locust stridulating
+in the air would be called upon to do if the present theory of sound were
+correct. He stated that a locust not weighing more than half a
+pennyweight, and that could not move an ounce weight, was supposed capable
+of setting 4 cubic miles of atmosphere into vibration, weighing
+120,000,000 tons, so that it would be displaced 440 times in one second,
+and any portion of the air could bend the human tympanic membrane once in
+and once out 440 times in one second; and that 40,000,000 people, nearly
+the whole population of the United States, could have their 5,000 pounds
+of tympanic membrane thus shaken by an insect that could not move an ounce
+weight to save its life; and that the 231,222 pounds of tympanic membrane
+of the entire population of the earth, amounting to 1,350,000,000, who
+could conveniently stand in 11¼ square miles, would be affected the same
+way by 34 locusts stridulating in the air. According to the barometric
+theory of Sir William Thomson, he showed that a locust would have to add
+60,000,000 pounds to the weight of the atmosphere.
+
+Under elasticity and density he stated that elasticity was a mere property
+of a body, and could not add one grain of force to that exercised by the
+locust, so as to assist it in performing such wonderful feats. Under
+interference he showed that the law of interference is fallacious; that no
+such thing occurs; and that in the experiment with the siren to show such
+fact, the octave is produced which of necessity ought to be when the
+number of orifices are alternately doubled, and the same effect would be
+produced with one disk with double the number of holes. Under the last
+head of his paper Dr. Mott proved that the membrana tympani was not
+necessary for good hearing, that in fact when it was punctured, a deaf man
+could in many cases be made to hear, and in fact it improved the hearing
+in general; the only reason why the tympanic membrane was not punctured
+oftener was that dust, heat, and cold were apt to injure the middle ear.
+
+In closing his paper Dr. Mott said that he would risk the fallacy of the
+current theory of sound on the argument advanced relating to the
+impossibility of the slow motion of a tuning fork to produce sonorous
+waves, and stated that he would retire if any one could show the fallacy
+of the argument; but if not, the wave theory must be abandoned as absurd
+and fallacious, as was the Ptolemaic system of astronomy, which was handed
+down from age to age until Copernicus and his aide de camp Galileo gave to
+the world a better system.
+
+       *       *       *       *       *
+
+
+
+
+THE ATTOCK BRIDGE.
+
+
+We give illustrations from _Engineering_ of a bridge recently constructed
+across the Indus River at Attock, for the Punjaub Northern State Railway.
+This bridge, which was opened on May 24, 1883, was erected under the
+direction of Mr. F.L. O'Callaghan, engineer in chief, Mr. H. Johnson
+acting as executive engineer, and Messrs. R.W. Egerton and H. Savary as
+assistants.
+
+[Illustration: BRIDGE OVER THE RIVER INDUS AT ATTOCK: PUNJAUB NORTHERN
+STATE RAILWAY, INDIA.]
+
+The principal spans cover a length of about 1,150 feet. It will be seen
+from the diagram that there is a difference of nearly 100 feet in the
+levels of high and low water.
+
+       *       *       *       *       *
+
+
+
+
+THE ELASTICITY OF METALS.
+
+
+M. Tresca has contributed to the _Comptes Rendus_ some observations on the
+effect of hammering, and the variation of the limit of elasticity of
+metals and materials used in the arts.
+
+He says that hitherto, in considering the deformation of solids under
+strain, two distinct periods, relative to their mechanical properties,
+have alone been recognized. These periods are of course the elastic limit
+and the breaking point. In the course of M. Tresca's own experiments,
+however, he has found it necessary to consider, at the end of the period
+of alteration of elasticity, a third state, geometrically defined and
+describable as a period of fluidity, corresponding to the possibility of a
+continuous deformation under the constant action of the same strain. This
+particular condition is only realized with very malleable or plastic
+bodies; and it may even be regarded as characteristic of such bodies,
+since its absence is noticeable in all non-malleable or fragile bodies,
+which break without being deformed. It is already known that the period of
+altered elasticity for hard or tempered steel is much less than for iron.
+In 1871 the author showed that steel or iron rails that had acquired a
+permanent set were at the same time perfectly elastic up to the limit of
+the load which they had already borne. With certain bars the same result
+was renewed five times in succession; and thus their period of perfect
+elasticity could be successively extended, while the coefficient of
+elasticity did not appear to sustain any appreciable modification. This
+process of repeated straining, when there is an absence of a certain
+hammering effect, renders malleable bodies somewhat similar to those which
+are not malleable and brittle. There is an indication here of another
+argument against the testing of steam boilers by exaggerated pressures
+before use, which process has the effect of rendering the plates more
+brittle and liable to sudden rupture.
+
+M. Tresca also protests against the elongation of metals under breaking
+strain tests being stated as a percentage of the length. The elongation is
+in all cases, chiefly local; and is therefore the same for a test piece
+12 inches or 8 inches long, being confined to the immediate vicinity of
+the point of rupture. The indication of elasticity should rather be sought
+for in the reduction of the area of the bar at the point of rupture. This
+portion of the bar is otherwise remarkable for having lost its original
+condition. It is condensed in a remarkable manner, and has almost
+completely lost its malleability. The final rupture, therefore, is that of
+a brittle zone of the metal, of the same character that may be produced by
+hammering. If a test bar, strained almost to the verge of rupture, be
+annealed, it will stretch yet further before breaking; and, indeed, by
+successive annealings and stretchings, may be excessively modified in its
+proportions.
+
+       *       *       *       *       *
+
+
+
+
+THE HARRINGTON ROTARY ENGINE.
+
+
+The chief characteristic or principle of this engine is the maintenance of
+an accurate steam and mechanical balance and the avoidance of cross
+pressure. The power is applied directly to the work, the only friction
+being that of the steel shaft in phosphor-bronze bearings. Referring to
+the cuts, Fig. 1 shows the engine and an electric dynamo on the same
+shaft, all connecting mechanism being done away with, and pounding
+obviated. There are but two parts to the engine (two disks which supply
+the place of all the ordinary mechanism), both of which are large, solid,
+and durable. These disks have a bearing surface of several inches on each
+other, preventing the passage of steam between them--a feature peculiar to
+this engine. Fig. 2 represents an end elevation partly in section, showing
+the piston, A, and the abutment disk, B, in the position assumed in the
+instant of taking steam through a port from the valve-chamber, E. Fig. 3
+is a vertical section through the center of Fig. 2, showing the relations
+of the disks, C, and the abutment disks, B, and gear. The piston disks and
+gear are attached to the driving shaft, H, and the abutment disks and gear
+are attached to the shaft, K. These shafts, H and K, as above stated, run
+in taper phosphor-bronze bearings, which are adjustable for wear or other
+causes by the screw-caps, O. The whole mechanism is kept rigidly in place
+by the flanged hub, r, bolted securely to the cylinder head, F. These
+flanged heads project through the cylinder head, touching the piston disk,
+and thereby prevent any end motion of the shaft, H, or its attachments.
+The abutment disks and shaft are furnished with similar inwardly
+projecting flanged hubs, which are provided with a recess, I, Fig. 2, on
+their periphery, located radially between the shaft, K, and the clearance
+space, J. Into this recess steam is admitted--through an inlet in the
+cylinder head not shown in the cuts. By this means the shaft, K, is
+relieved of all side pressure. The exhaust-port, which is very large and
+relieves all back pressure, is shown at D. The pistons and disks are made
+to balance at the speed at which the engine is intended to run. The
+steam-valve, for which patent is pending, is new in principle. It has a
+uniform rotating motion, and, like the engine, is steam and mechanically
+balanced. The governor is located in the flywheel, and actuates the
+automatic cut-off, with which it is directly connected, without the
+intervention of an eccentric, in such a way as to vary the cut-off without
+changing the point of admission. By this means is secured uniformity of
+motion under variable loads with variable boiler pressure. It also secures
+the advantage resulting from high initial and low terminal pressure with
+small clearances and absence of compression, giving a large proportionate
+power and smooth action.
+
+Expansion has been excellently provided for, the steam passing entirely
+around before entering the cylinder. These engines are mounted on a
+bed-plate which may be set on any floor without especial preparation
+therefor. The parts are all made interchangeable. A permanent indicator is
+provided which shows the exact point of cut-off. The steam-port is
+exceptionally large, being one-fourth of the piston area. Reciprocating
+motion is entirely done away with. The steam is worked at the greatest
+leverage of the crank through the entire stroke. Among the other chief
+advantages claimed for this engine are direct connection to the machinery
+without belts, etc., impossibility of getting out of line, uniform crank
+leverage, capacity for working equally well slow or fast, etc. It has but
+one valve, which is operated by gear from the shaft, as shown, traveling
+at one-half the velocity of the piston.
+
+[Illustration: Fig. 1.--THE HARRINGTON ROTARY ENGINE COUPLED TO A DYNAMO.]
+
+With this engine a speed of 5,000 revolutions per minute is easily
+attainable, while, as a matter of fact and curiosity, a speed of 8,000
+revolutions per minute has been obtained. An engine of this class was run
+at the Illinois Inter-State Exposition at Chicago for six weeks at a
+uniform speed of 1,050 revolutions per minute, furnishing the power for
+twenty-three electric arc lights, with a steam pressure not exceeding
+fifty-five pounds per square inch, and cutting off at from one-tenth to
+one-sixth of the stroke. It was taking steam from a large main-pipe, so
+there was no opportunity for an exact test of the amount of fuel used, but
+from a careful mathematical calculation it must have been developing one
+horse-power from three pounds of coal.
+
+The inventor claims that, as his engine works the steam expansively, even
+better results would have been obtained had the engine been furnished
+steam at 100 pounds per square inch.
+
+[Illustration: Figs. 2 and 3.--DETAILS OF HARRINGTON ENGINE.]
+
+The Harrington Rotary Engine Company, 123 Clinton Street, Chicago, are the
+owners and manufacturers.
+
+       *       *       *       *       *
+
+In a can of peas sold in Liverpool recently the public analyst found two
+grains of crystallized sulphate of copper, a quantity sufficient to
+injuriously affect human health. The defendant urged that the public
+insisted upon having green peas; and that artificial means had to be
+resorted to to secure the required color.
+
+       *       *       *       *       *
+
+
+
+
+TESTING CAR VARNISHES.
+
+By D.D. ROBERTSON.
+
+
+At the Master Car-Painters' Convention, D.D. Robertson, of the Michigan
+Central, read the following paper on the best method of testing varnishes
+to secure the most satisfactory results as to their durability, giving
+practical suggestions as to the time a car may safely remain in the
+service before being taken in for revarnishing:
+
+The subject which the association has assigned to me for this convention
+has always been regarded as important. There is no branch of the business
+which gives the painter more anxiety than the varnishing department. It is
+more susceptible to an endless variety of difficulties, and therefore
+needs more close and careful attention, than all other branches put
+together, and even with all the research and practical experience which
+has been given to the subject we are yet far from coming to a definite
+conclusion as to the causes of many of the unfavorable results.
+
+Beauty and durability are what we aim at in the paint shop, and from my
+experience in varnish work we may have beauty without durability, but we
+have rarely durability without beauty, so that the fewer defects of any
+kind in our work caused by inferior material, inferior workmanship, or any
+other cause, it is more likely to be durable, and ought, therefore, to
+possess beauty. There are certain qualifications absolutely necessary to
+durability in varnish. The material of which it is made must be of the
+proper kind, pure and unadulterated; the manipulation in manufacturing
+must be correct as to time, quantities, temperature, handling, etc., and
+age is also necessary. The want of durability arising from the quality of
+the materials, or from the manner of manufacturing, the painter has no
+control over; but let me say here, that frequently a first-class varnish
+has been used upon a car, and after being in service for a short time it
+deadens, checks, cracks, chips, or flakes, and therefore shows a very poor
+record. The varnish is condemned, when in reality, had the varnish been
+applied under different circumstances and over different work, the result
+would have been good and the durability satisfactory.
+
+I am satisfied that in many cases first-class varnish has to bear the
+odium, when the root of the evil is to be found nearer the foundation. The
+leading varnish manufacturers of this country have expended large fortunes
+to secure the best skill and appliances, and, indeed, to do everything to
+bring their goods to perfection. Their standing and respectability put
+them beyond suspicion, and their reputation is of too much value for them
+knowingly to put into the hands of large consumers an inferior article;
+and even when we have just cause to complain of the varnish, we ought to
+be charitable enough to attribute the mistake to circumstances beyond
+their control (for every kettleful is subjected to such circumstances),
+and not to charge them with using cheap or inferior material for the sake
+of gain.
+
+If the question which has been given me means to give some method of
+testing before using, I confess my inability to answer. For varnish to be
+pronounced "durable" must be composed of the materials to make it so, and
+to ascertain this, chemistry must be called in to test it. Comparatively
+few painters understand chemistry sufficiently to analyze, and if they
+did, and found the material all that is necessary, the manipulation may
+have been defective, so as to injure its wearing qualities, and therefore
+I cannot suggest any way of pronouncing varnish durable before using it.
+
+As to the common custom of hanging out boards prepared and varnished to
+the exposure of the sun and weather for months does not seem to me to be
+the correct way of testing durability. It is true we may by this mode get
+some idea of wearing properties, but the most thorough and correct way is
+to put the varnish to the same exposure, the tear and wear, that it would
+have in the regular service on the road on which it is to run. Cars while
+running are exposed to circumstances which boards on the wall are not
+subjected to. The cars under my charge run through two different countries
+and three different States, and therefore subjected to such a variety of
+climate and soil that the testing by stationary boards would completely
+fail to give the correct result. For example: I have placed two sample
+boards, prepared and varnished, and exposed them to all kinds of weather
+and to the constant and steady rays of the sun for an equal length of
+time, and both gave favorable results; and I have also put the same
+varnishes on a car and found very different results. One of the varnishes
+having some properties adapted to resist the friction caused by cinders,
+sand, and dust, and consequently not so liable to cut the surface, and
+therefore much more durable.
+
+The system which I adopted long ago, and to which I still adhere (not on
+account of "old fogyism," but for want of better), is as follows: I have
+two varnishes which I want to put into competition to test their relative
+merits. With varnish No. 1, I do the south half of the east end of the car
+and the east half of the south side of the car, the north half of the west
+end, and also the west end of the north side; this is also done with the
+same varnish. On the other half of the car varnish No. 2 is put.
+
+Thus you will see it is so placed that, should the car be turned at any
+time, both varnishes on each side will have the same exposure and
+circumstances to contend with. This I regard as the best method to test
+the durability of varnish. And again let me say that it would be wrong for
+me to argue that because the varnish which I use gives me the best
+results, therefore I would regard it the best for all to use. This would
+be wrong, inasmuch as we have a diversity of climates between Maine and
+California, and between the extreme northern and southern States. The
+varnish which has failed to give me satisfaction may be most suitable for
+other parts of the Union.
+
+As to the second part of my subject, "What length of time may a car safely
+remain in service before being taken in for revarnishing?" this must be
+regulated by the nature of the run and general treatment of the car while
+in service. Through cars are frequently continuously on the road, and
+little or no opportunity can be had to attend to them while in service.
+Such cars should be called in earlier than those which make shorter runs,
+and where ample time is allowed at both ends of the journey to be kept in
+order. And again, cars which are run nearest the engine cannot make so
+large a running record as those less exposed. Some roads, for a variety of
+reasons which might be given, can run cars for 14 months with less wear
+than others can run 12 months. So that I hold that the master painter on
+every road should keep a complete and correct record of his cars, and have
+an opportunity to examine these at intervals and report their condition,
+in order to have them called in before they are too far gone for
+revarnishing. If this system was more frequently adopted, the rolling
+stock of our roads would be more attractive, and the companies would be
+the gainers.
+
+I cannot lay down a standard rule as to the exact time a car should remain
+in service before being called in for revarnishing, but I find as a
+general rule with the cars on the Michigan Central Railroad that they
+should not exceed 12 months' service, and new cars, or those painted from
+the foundation, should not be allowed to run over 10 months the first
+year. By thus allowing a shorter period the first year the car will look
+better and wear longer by this mode of treatment. Cars treated in this way
+can be kept running for six and seven years without repainting.
+
+       *       *       *       *       *
+
+
+
+
+THE FIXATION OF MAGNETIC PHANTOMS.
+
+
+When we place a thin sheet of cardboard or glass upon a magnet and scatter
+iron filings over it, we observe the iron to take certain positions and
+trace certain lines which Faraday has styled lines of magnetic force, or,
+more simply, lines of force. The figure, as a whole, which is thus formed
+constitutes a magnetic phantom. The forms of the latter vary with that of
+the magnet, the relative positions of the magnet and plate, etc.
+
+[Illustration: METHOD OF FIXING MAGNETIC PHANTOMS.]
+
+The whole space submitted to the influence of the magnet constitutes a
+_magnetic field_, which is characterized by the presence of these lines of
+force, and the study of which is of the most important character as
+regards electro-magnetic action and that of induction. In order to study
+these phantoms it is convenient to fix them so that they can be preserved,
+projected, or photographed. Fig. 1 shows how they may be fixed. To effect
+this, we cover the plate with a layer of mucilage of gum arabic, allow the
+latter to harden, and then place the plate over the magnet. Next, iron
+filings are scattered over the surface by means of a small sieve, and,
+when the curves are well developed,[1] the surface is moistened by the aid
+of an ordinary vaporizer. The layer of gum arabic thus becomes softened
+and holds the iron filings so that the particles cannot change position.
+When the gum has hardened again, the magnet is removed, and the phantom is
+fixed.
+
+[Footnote 1: The curves are obtained by striking the plate lightly with a
+glass rod.]
+
+We thus have a tangible representation of the magnetic field produced by
+the magnet in the plane of the glass plate or sheet of paper. The number
+of these lines, or their density, is at every point proportional to the
+intensity of the field, and the curves that are traced show their
+direction. To finish the definition of the field, it remains to determine
+the direction of these lines of force. Such direction is, by definition,
+and conventionally, that in which the north pole of a small magnetic
+needle, free to move in the field, would travel. It results from this
+definition that the lines of force issue from the north pole of a magnet
+and re-enter the south pole, since the north pole of a magnet repels the
+north pole of a needle, and _vice versa._
+
+These considerations relative to the direction and intensity of the
+magnetic field are of the highest importance for the physical theory of
+magneto-electric machines.
+
+The following is another method of fixing phantoms, as employed by Prof.
+Bailie, of the Industrial School of Physics and Chemistry of the City of
+Paris. He begins by forming the phantom, in the usual way, upon paper
+prepared with ferrocyanide, and exposes it to daylight for a sufficient
+length of time. The filings form a screen which is so much the more
+perfect in proportion as it is denser, and, after fixation, there is
+obtained a negative phantom, that is to say, one in which the parts where
+the field is densest have remained white.
+
+The same processes of fixation apply equally well to galvanic phantoms,
+that is to say, to the galvanic fields produced by the passage of a
+current in a conductor, and which consists of analogous lines of force.
+The processes may be employed very efficaciously and with certainty of
+success.--_La Nature._
+
+       *       *       *       *       *
+
+
+
+
+A CHIPPENDALE SIDEBOARD.
+
+
+[Illustration: A CHIPPENDALE SIDEBOARD.]
+
+Our illustration this week is of a unique and handsome piece of
+Chippendale work. The outline is elegant, and the scrollings delicate. The
+pedestals are peculiar in their form, the panels being carved in
+draperies, etc. In the frieze are two drawers, with grotesque heads
+forming the handles. The back is fitted with shaped glass and surmounted
+by an eagle. The whole forms a very characteristic piece of work of the
+period, having been made about 1760-1770. As our readers are aware, Thomas
+Chippendale published his book of designs in 1764, with the object of
+promoting good French design in this field of art. This piece of furniture
+was sold at auction lately for 85 guineas.--_Building News._
+
+       *       *       *       *       *
+
+
+
+
+LIQUEFACTION OF THE ELEMENTARY GASES.
+
+By JULES JAMIN, of the Institute of France.
+
+
+The earlier experiments of MM. Cailletet and Raoul Pictet in the
+liquefaction of gases, and the apparatus by means of which they performed
+the process, were described in the _Popular Science Monthly_, March and
+May, 1878. The experiments have since been continued and improved upon by
+MM. Cailletet and Pictet, and others, with more complete results than had
+been attained at the time the first reports were published, and with the
+elucidation of some novel properties of gases, and the disclosure of
+relations, previously not well understood, between the gaseous and the
+liquid condition. The experiments of Faraday, in the compression of gases
+by the combined agency of pressure and extreme cold, left six gases which
+still refused to enter into the liquid state. They were the two elements
+of the atmosphere (oxygen and nitrogen), nitric oxide, marsh-gas, carbonic
+oxide, and hydrogen. Many new experiments were tried before the principle
+that governs the change from the gaseous to the liquid, or from the liquid
+to the gaseous form was discovered. Aime sank manometers filled with air
+into the sea till the pressure upon them was equal to that of four hundred
+atmospheres; Berthelot, by the expansion of mercury in a thermometer tube,
+succeeded in exerting a pressure of seven hundred and eighty atmospheres
+upon oxygen. Both series of experiments were without result. M. Cailletet,
+having fruitlessly subjected air and hydrogen to a pressure of one
+thousand atmospheres, came to the conclusion that it was impossible to
+liquefy those gases at the ordinary temperature by pressure alone.
+Previously it had been thought that the obstacle to condensing gases by
+pressure alone lay in the difficulty of obtaining sufficient pressure, or
+in that of finding a vessel suitable for manipulation that would be
+capable of resisting it. M. Cailletet's thought led to the discovery of
+another fundamental property of gases.
+
+The experiments of Despretz and Regnault had shown that the scope of
+Mariotte's law (that the volume of gases increases or diminishes inversely
+as the pressure upon them) was limited, and that its limits were different
+with different substances. Andrews confirmed the observations of these
+investigators, and extended them. Compressing carbonic acid at 13° C. (55°
+Fahr.), he found that the rate of diminution in volume increased more
+rapidly than Mariotte's law demanded, and at a progressive rate. At fifty
+atmospheres the gas all at once assumed the liquid form, became very
+dense, and fell to the bottom of the vessel, where it remained separated
+from its vapor by a clearly defined surface, like that which distinguishes
+water in the air. Experimenting in the same way with the gas at a higher
+temperature (21° C. or 70° Fahr.), he found that the same result was
+produced, but more slowly; and it seemed to be heralded in advance by a
+more rapid diminution in volume previous to the beginning of the change,
+which continued after the process had been accomplished; as if an
+anticipatory preparation for the liquid state were going on previous to
+the completion of the change. Performing the experiment again at 32° C.
+(90° Fahr.), the anticipatory preparation and the after-continuation of
+the contraction were more marked, and, instead of a separate and distinct
+liquid, wavy and mobile striæ were perceived on the sides of the vessel as
+the only signs of a change of state which had not yet been effected. At
+temperatures above 32° C. (90° Fahr.), there were neither striæ nor
+liquefaction, but there seemed to be a suggestion of them, for, under a
+particular degree of pressure, the density of the gas was augmented, and
+its volume diminished at an increasing rate. The temperature of 32° C.
+(90° Fahr.) is, then, a limit, marking a division between the temperatures
+which permit and those which prevent liquefaction; it is the critical
+point, at which is defined the separation, for carbonic acid, between two
+very distinct states of matter. Below this point, the particular matter
+may assume the aspect of a liquid; above it, the gas cannot change its
+appearance, but enters into the opposite constitution from that of a
+liquid.
+
+Generally, a liquid has considerably greater density than its vapor. But,
+if a vessel containing both is heated, the liquid experiences a dilatation
+which is gradually augmented till it equals and even exceeds that of the
+gas; whence, of course, an equal volume of the liquid will weigh less and
+less. On the other hand, a constantly larger quantity of vapor is formed,
+which accumulates above the liquid and becomes heavier and heavier. Now if
+the density of the vapor increases, and that of the liquid diminishes,
+they will reach a point, under a suitable temperature, when they will be
+the same. There will then be no reason for the liquid to sink or the vapor
+to rise, or for the existence of any line of separation between them, and
+they will be mixed and confounded. They will no longer be distinguishable
+by their heat of constitution. It is true that, in passing into the state
+of a vapor, a liquid absorbs a great deal of latent heat, but that is
+employed in scattering the molecules and keeping them at a distance; and
+there will be none of it if the distance does not increase. We are then,
+at this stage of our experiments, in the presence of a critical point, at
+which we do not know whether the matter is liquid or gaseous; for, in
+either condition, it has the same density, the same heat of constitution,
+and the same properties. It is a new state, the gaso-liquid state. An
+experiment of Cagniard-Latour re-enforced this explanation of the
+phenomena. Heating ether in closed vessels to high temperatures, he
+brought it to a point where the liquid could be made wholly to disappear,
+or to be suddenly reformed on the slightest elevation or the slightest
+depression of temperature accordingly as it was raised just above or
+cooled to just below the critical point. The discovery of these properties
+suggested an explanation of the failure of previous attempts to liquefy
+air. Air at ordinary low temperatures is in the gaso-liquid condition, and
+its liquefaction is not possible except when a difference exists between
+the density of the vapor and that of the liquid greater than it is
+possible to produce under any conditions that can exist then. It was
+necessary to reduce the temperature to below the critical point; and it
+was by adopting this course that MM. Cailletet and Raoul Pictet achieved
+their success. The rapid escape of the compressed gas itself from a
+condition of great condensation at an extremely low temperature was
+employed as the agent for producing a greater degree of cold than it had
+been possible before to obtain. M. Cailletet used oxygen escaping at -29°
+C. from a pressure of three hundred atmospheres; M. Raoul Pictet, the same
+gas escaping at -140° from a pressure of three hundred and twenty
+atmospheres; and both obtained oxygen and nitrogen, and M. Pictet
+hydrogen, in what they thought was a liquid, and possibly even in a solid
+form.
+
+Still, it could not be asserted that hydrogen and the elements of the air
+had been completely liquefied. These gases had not yet been seen collected
+in the static condition at the bottom of a tube and separated from their
+vapors by the clearly defined concave surface which is called a
+_meniscus._ The experiments had, however, proved that liquefaction is
+possible at a temperature of below -120° C. (-184° Fahr.). To make the
+process practicable, it was only necessary to find sufficiently powerful
+refrigerants; and these were looked for among gases that had proved more
+refractory than carbonic acid and protoxide of nitrogen. M. Cailletet
+selected ethylene, a hydrocarbon of the same composition as illuminating
+gas, which, when liquefied by the aid of carbonic acid and a pressure of
+thirty-six atmospheres, boils at -103° C. (-153° Fahr.). M. Wroblewski, of
+Cracow, who had witnessed some of M. Cailletet's experiments, and obtained
+his apparatus, and M. Olzewski, in association with him, also experimented
+with ethylene, and had the pleasure of recording their first complete
+success early in April, 1883. Causing liquid ethylene to boil in an
+air-pump vacuum at -103° C., they were able to produce a temperature of
+-150° C. (-238° Fahr.), the lowest that had ever been observed. Oxygen,
+having been previously compressed in a glass tube, became a permanent
+liquid, with a clearly defined meniscus. It presented itself, like the
+other liquefied gases, under the form of a transparent and colorless
+substance, resembling water, but a little less dense. Its critical point
+was marked at -113° C. (-171° Fahr.), below which the liquid could be
+formed, but never above it; while it boiled rapidly at -186° C. (-303°
+Fahr.). A few days afterward, the Polish professors obtained the
+liquefaction of nitrogen, a more refractory gas, under a pressure of
+thirty-six atmospheres, at -146° C. (-231° Fahr.). Long, difficult, and
+expensive operations were required to produce this result, for the extreme
+degree of cold it demanded had to be produced by boiling large quantities
+of ethylene in a vacuum. M. Cailletet devised a cheaper process, by
+employing another hydrocarbon that rises from the mud of marshes, and is
+called _formene_. It is less easily liquefied than ethylene, but for that
+very reason can be boiled in the air at a lower temperature, or at -160°C.
+(-256° Fahr.); and at this temperature nitrogen and oxygen can be
+liquefied in a bath of formene as readily as sulphurous acid in the common
+freezing mixture.
+
+MM. Cailletet, Wroblewski, and Olzewski have continued their experiments
+in liquefaction, and acquired increased facility in the handling of liquid
+ethylene, formene, atmospheric air, oxygen, and nitrogen. M. Olzewski was
+able to report to the French Academy of Sciences, on the 21st of July,
+1884, that by placing liquefied nitrogen in a vacuum he had succeeded in
+producing a temperature of -213°C. (-351° Fahr.), under which hydrogen was
+liquefied. Contrary to the suppositions founded on the metallic behavior
+of this element, that it would present the appearance of a molten metal,
+like mercury, the liquid had the mobile behavior and the transparency of
+the hydrocarbons.
+
+       *       *       *       *       *
+
+
+
+
+EXAMINATION OF FATS.
+
+
+The methods employed up to the present in examination of fats, animal and
+vegetable, are mere reactions lacking general application; scattered
+throughout the literature, and doubtful with regard to reliability, they
+are of little or no value to the experimenter--an approximate quantitative
+examination even of a simple mixture being exceedingly difficult if not
+impossible, since the qualitative composition of fatty substances is the
+same, and the separation of the nearer components impracticable. The
+object of analysis consisted in estimating the accompanying impurities of
+fat, as, resin, albuminoids, and pigments. The nature of these substances
+depends on the mode of extraction and preservation of the fat, and are
+subject in the course of time to alteration. The only reaction based upon
+the chemical constitution of fat is produced by treatment of oleic or
+linoleic acid with nitrous acid, which therefore is of some value in the
+examination of drying oils. Of general application are the methods which
+correspond to the chemical constitution of fats, and thus determine the
+relative quantity of the components; advantage can then be derived from
+qualitative reactions, inasmuch as they further affirm the result of the
+quantitative test, or dispel any doubt with regard to the correctness of
+the result. The principal methods which comply with these demands have
+been carefully studied by Hueble for the purpose of discovering a process
+of general application; methods founded on the determination of density,
+freezing, and melting point were compared with those dependent on the
+solubility of fatty substances in glacial acetic acid or a mixture of
+alcohol and acetic acid; also the method of Hehner for testing of butter,
+the determination of glycerine and oleic acid, and at length the process
+of saponification. Nearly all fats contain members belonging to one of the
+three series of fatty acids, _e.g._, acids of the type of acetic acid
+(stearic and palmitic acids); such as are derivatives of acrylic acid
+(oleic and erucic acids); and such as are homologues of tetrolic acid
+(linoleic acid). It is likely that the relative quantity of each of these
+acids is variable, with regard to the same fat, within definite limits,
+and changes with the nature of the fatty substance. The groups of fatty
+acids are distinguished by a characteristic deportment toward halogens;
+while members of the first series are indifferent to haloids, those of the
+second and third class combine readily, without suffering substitution,
+with two respectively four atoms of a haloid. In view of this behavior the
+first series is termed saturated, the second and third that of unsaturated
+acids. Addition of halogen to one of the unsaturated acids yields on
+subsequent examination an invariable quantity of the former, representing
+two or four atoms, according to one or the other of unsaturated groups;
+and as the molecular weights of fatty acids are unequal, the percentage
+quantity of halogen will be found varying with regard to members belonging
+to the same series. The amount of iodine absorbed by some of the fatty
+acids is illustrated by the following items:
+
+Hypogallic acid, C_{16}H_{30}O_{2}, combines with 100.00 grammes. iodine.
+Oleic acid,      C_{18}H_{34}O_{2}      "      "   90.07    "        "
+Erucic acid,     C_{22}H_{42}O_{2}      "      "   75.15    "        "
+Ricinoleic acid, C_{18}H_{34}O_{3}      "      "   85.24    "        "
+Linoleic acid,   C_{16}H_{28}O_{2}      "      "  201.59    "        "
+
+Of the halogens employed in the examination, iodine is preferable to
+either chlorine or bromine; it acts but slowly at ordinary, but
+energetically at elevated temperatures. The reagents are solution of
+mercury iodo-chloride prepared by dissolving of 25 grms. iodine, 500 c.c.
+alcohol of 95 per cent., and of 30 grms. mercury chloride in an equal
+measure of the same solvent; both liquids are filtered and united; a
+standard solution of sodium hyposulphite produced by digestion of 24 grms.
+of the dry salt with 1 liter water and titration with iodine solution;
+solution of potassium iodide of 1:10; chloroform, and finally a solution
+of starch. The above solution of mercury iodo-chloride acts on both free
+unsaturated acids and glycerides, producing addition products. For testing
+a sample of 0.2 to 0.4 grm. of a liquid, and from 0.8 to 1.0 grm. of a
+solid fat being used, which is dissolved in 10 c.c. chloroform and treated
+with 20 c.c. mercury iodo-chloride solution run into it from a burette, if
+the liquid appear opalescent a further measure of chloroform is
+introduced, while the amount of mercury iodo-chloride must be such as to
+produce a brownish coloration of the chloroform for two subsequent hours.
+The excess of iodine is determined, on addition of from 10 to 15 c.c.
+potassium iodide solution and 150 c.c. distilled water, by means of
+caustic soda. From a burette divided into 0.1 c.c. a solution of caustic
+soda is poured with continual gyration of the flask into the tinged
+liquid, and the percentage of combined iodine ascertained by difference;
+for this purpose 20 c.c. of mercury iodo-chloride are tested, on
+introduction of a solution of potassium iodide and starch, previously to
+its use as reagent. Adulteration of solid or semi-liquid fats, especially
+lard, butter, and tallow, with vegetable oils are readily detected by this
+method, since the latter yield on examination a high percentage of iodine.
+Animal fats, absorb comparatively less halogen than vegetable fats, and
+the power to combine with iodine increases with the transition from the
+solid to the liquid state, and attains its maximum with vegetable
+oils--the method being adapted to the examination of fat mixtures
+containing glycerides and free saturated fatty acids, provided that
+substances which under similar conditions combine with iodine are absent.
+These conditions are fulfilled with regard to the examination of animal
+fats and soap. Ethereal oils are also acted upon by iodine; the reaction
+proceeds similar to that observed in ordinary fat mixtures. Alcoholic
+mercury iodo-chloride can probably be used with success in synthetical
+chemistry, as it allows determination of the free affinities of the
+molecule and conversion of unsaturated compounds into saturated
+chlorine-iodo addition products.--_Rundschau._
+
+       *       *       *       *       *
+
+
+
+
+NOTES ON NITRIFICATION.[2]
+
+[Footnote 2: A paper by R. Warington, read before the Chemical Section of
+the British Association at Montreal.]
+
+By R. WARINGTON.
+
+
+In the following brief notes I propose to consider in the first place the
+present position of the theory of nitrification, and next to give a short
+account of the results of some recent experiments conducted in the
+Rothamsted Laboratory.
+
+_The Theory of Nitrification._--The production of nitrates in soils, and
+in waters contaminated with sewage, are facts thoroughly familiar to
+chemists. It is also well known that ammonia, and various nitrogenous
+organic matters, are the materials from which the nitric acid is produced.
+Till the commencement of 1877 it was generally supposed that this
+formation of nitrates from ammonia or nitrogenous organic matter was the
+result of simple oxidation by the atmosphere. In the case of soil it was
+imagined that the action of the atmosphere was intensified by the
+condensation of oxygen in the pores of the soil; in the case of waters no
+such assumption was possible. This theory was most unsatisfactory, as
+neither solutions of pure ammonia, nor of any of its salts, could be
+nitrified in the laboratory by simple exposure to air. The assumed
+condensation of oxygen in the pores of the soil also proved to be a
+fiction as soon as it was put by Schloesing to the test of experiment.
+
+Early in 1877, two French chemists, Messrs. Schloesing and Müntz,
+published preliminary experiments showing that nitrification in sewage and
+in soils is the result of the action of an organized ferment, which occurs
+abundantly in soils and in most impure waters. This entirely new view of
+the process of nitrification has been amply confirmed both by the later
+experiments of Schloesing and Müntz, and by the investigations of other
+chemists, among which are those by myself conducted in the Rothamsted
+Laboratory.
+
+The evidence for the ferment theory of nitrification is now very complete.
+Nitrification in soils and waters is found to be strictly limited to the
+range of temperature within which the vital activity of living ferments is
+confined. Thus nitrification proceeds with extreme slowness near the
+freezing-point, and increases in activity with a rise in temperature till
+37° is reached; the action then diminishes, and ceases altogether at 55°.
+Nitrification is also dependent on the presence of plant-food suitable for
+organisms of low character. Recent experiments at Rothamsted show that in
+the absence of phosphates no nitrification will occur. Further proof of
+the ferment theory is afforded by the fact that antiseptics are fatal to
+nitrification. In the presence of a small quantity of chloroform, carbon
+bisulphide, salicylic acid, and apparently also phenol, nitrification
+entirely ceases. The action of heat is equally confirmatory. Raising
+sewage to the boiling-point entirely prevents its undergoing
+nitrification. The heating of soil to the same temperature effectually
+destroys its nitrifying power. Finally, nitrification can be started in
+boiled sewage, or in other sterilized liquid of suitable composition, by
+the addition of a few particles of fresh surface soil or a few drops of a
+solution which has already nitrified; though without such addition these
+liquids may be freely exposed to filtered air without nitrification taking
+place.
+
+The nitrifying organism has been submitted as yet to but little
+microscopical study; it is apparently a micrococcus.
+
+It is difficult to conceive how the evidence for the ferment theory of
+nitrification could be further strengthened; it is apparently complete in
+every part. Although, however, nearly the whole of this evidence has been
+before the scientific public for more than seven years, the ferment theory
+of nitrification can hardly be said to have obtained any general
+acceptance; it has not indeed been seriously controverted, but neither has
+it been embraced. In hardly a single manual of chemistry is the production
+of saltpeter attributed to the action of a living ferment existing in the
+soil. Still more striking is the absence of any recognition of the
+evidence just mentioned when we turn to the literature and to the public
+discussions on the subjects of sewage, the pollution of river water, and
+other sanitary questions. The oxidation of the nitrogenous organic matter
+of river water is still spoken of by some as determined by mere contact
+with atmospheric oxygen, and the agitation of the water with air as a
+certain means of effecting oxidation; while by others the oxidation of
+nitrogenous organic matter in a river is denied, simply because free
+contact with air is not alone sufficient to produce oxidation. How much
+light would immediately be thrown on such questions if it were recognized
+that the oxidation of organic matter in our rivers is determined solely by
+the agency of life, is strictly limited to those conditions within which
+life is possible, and is most active in those circumstances in which life
+is most vigorous. It is surely most important that scientific men should
+make up their minds as to the real nature of those processes of oxidation
+of which nitrification is an example. If the ferment theory be doubted,
+let further experiments be made to test it, but let chemists no longer go
+on ignoring the weighty evidence which has been laid before them. It is
+partly with the view of calling the attention of English and American
+chemists to the importance of a decision on this question that I have been
+induced to bring this subject before them on the present occasion. I need
+hardly add that such results as the nitrification of sewage by passing it
+through sand, or the nitrification of dilute solutions of blood prepared
+without special precaution, are no evidence whatever against the ferment
+theory of nitrification. If it is to be shown that nitrification will
+occur in the absence of any ferment, it is clear that all ferments must be
+rigidly excluded during the experiments; the solutions must be sterilized
+by heat, the apparatus purified in a similar manner, and all subsequent
+access of organisms carefully guarded against. It is only experiments made
+in this way that can have any weight in deciding the question.
+
+Leaving now the theory of nitrification, I will proceed to say a few
+words, first, as to the distribution of the nitrifying organism in the
+soil; secondly, as to the substances which are susceptible of
+nitrification; thirdly, upon certain conditions having great influence on
+the process.
+
+_The Distribution of the Nitrifying Organism in the Soil._--Three series
+of experiments have been made on the distribution of the nitrifying
+organism in the clay soil and subsoil at Rothamsted. Advantage was taken
+of the fact that deep pits had been dug in one of the experimental fields
+for the purpose of obtaining samples of the soil and subsoil. Small
+quantities of soil were taken from freshly-cut surfaces on the sides of
+these pits at depths varying from 2 inches to 8 feet. The soil removed was
+at once transferred to a sterilized solution of diluted urine, which was
+afterward examined from time to time to ascertain if nitrification took
+place. These experiments are hardly yet completed; the two earlier series
+of solutions have, however, been examined for eight and seven months
+respectively. In both these series the soil taken from 2 inches, 9 inches,
+and 18 inches from the surface has been proved to contain the nitrifying
+organism by the fact that it has produced nitrification in the solutions
+to which it was added; while in twelve distinct experiments made with soil
+from greater depths no nitrification has yet occurred, and we must
+therefore conclude that the nitrifying organism was not present in the
+samples of soil taken. The third series of experiments has continued as
+yet but three months and a half; at present no nitrification has occurred
+with soil taken below 9 inches from the surface. It would appear,
+therefore, that in a clay soil the nitrifying organism is confined to
+about 18 inches from the surface; it is most abundant in the first 6
+inches. It is quite possible, however, that in the channels caused by
+worms, or by the roots of plants, the organism may occur at greater
+depths. In a sandy soil we should expect to find the organism at a lower
+level than in clay, but of this we have as yet no evidence. The facts here
+mentioned are in accordance with the microscopical observations made by
+Koch, who states that the micro-organisms in the soils he has investigated
+diminish rapidly in number with an increasing depth; and that at a depth
+of scarcely 1 meter the soil is almost entirely free from bacteria.
+
+Some very practical conclusions may be drawn from the facts now stated. It
+appears that the oxidation of nitrogenous matter in soil will be confined
+to matter near the surface. The nitrates found in the subsoil and in
+subsoil drainage waters have really been produced in the upper layer of
+the soil, and have been carried down by diffusion, or by a descending
+column of water. Again, in arranging a filter bed for the oxidation of
+sewage, it is obvious that, with a heavy soil lying in its natural state
+of consolidation, very little will be gained by making the filter bed of
+considerable depth; while, if an artificial bed is to be constructed, it
+is clearly the top soil, rich in oxidizing organisms, which should be
+exclusively employed.
+
+_The Substances Susceptible of Nitrification._--The analyses of soils and
+drainage waters have taught us that the nitrogenous humic matter resulting
+from the decay of plants is nitrifiable; also that the various nitrogenous
+manures applied to land, as farmyard manure, bones, fish, blood, rape
+cake, and ammonium salts, undergo nitrification in the soil. Illustrations
+of many of these facts from the results obtained in the experimental
+fields at Rothamsted have been published by Sir J.B. Lawes, Dr. J.H.
+Gilbert, and myself, in a recent volume of the _Journal_ of the Royal
+Agricultural Society of England. In the Rothamsted Laboratory, experiments
+have also been made on the nitrification of solutions of various
+substances. Besides solutions containing ammonium salts and urea, I have
+succeeded in nitrifying solutions of asparagine, milk, and rape cake.
+Thus, besides ammonia, two amides, and two forms of albuminoids have been
+found susceptible of nitrification. In all cases in which amides or
+albuminoids were employed, the formation of ammonia preceded the
+production of nitric acid. Mr. C.F.A. Tuxen has already published in the
+present year two series of experiments on the formation of ammonia and
+nitric acids in soils to which bone-meal, fish-guano, or stable manure had
+been applied; in all cases he found the formation of ammonia preceded the
+formation of nitric acid.
+
+As ammonia is so readily nitrifiable, we may safely assert that every
+nitrogenous substance which yields ammonia when acted upon by the
+organisms present in soil is also nitriflable.
+
+_Certain Conditions having Great Influence in the Process of
+Nitrification._--If we suppose that a solution containing a nitrifiable
+substance is supplied with the nitrifying organism, and with the various
+food constituents necessary for its growth and activity, the rapidity of
+nitrification will depend on a variety of circumstances:
+
+1. The degree of concentration of the solution is important. Nitrification
+always commences first in the weakest solution, and there is probably in
+the case of every solution a limit of concentration beyond which
+nitrification is impossible.
+
+2. The temperature has great influence. Nitrification proceeds far more
+rapidly in summer than winter.
+
+3. The presence or absence of light is important. Nitrification is most
+rapid in darkness; and in the case of solutions, exposure to strong light
+may cause nitrification to cease altogether.
+
+4. The presence of oxygen is of course essential. A thin layer of solution
+will nitrify sooner than a deep layer, owing to the larger proportion of
+oxygen available. The influence of depth of fluid is most conspicuous in
+the case of strong solutions.
+
+5. The quantity of nitrifying organism present has also a marked effect. A
+solution seeded with a very small amount of organism will for a long time
+exhibit no nitrification, the organism being (unlike some other bacteria)
+of very slow growth. A solution receiving an abundant supply of the
+ferment will exhibit speedy nitrification, and strong solutions may by
+this means be successfully nitrified, which with small seedings would
+prove very refractory. The speedy nitrification which occurs in soil (far
+more speedy than in experiments in solutions under any conditions yet
+tried) is probably owing to the great mass of nitrifying organisms which
+soil contains, and to the thinness of the liquid layer which covers the
+soil particles.
+
+6. The rapidity of nitrification also depends on the degree of alkalinity
+of the solution. Nitrification will not take place in an acid solution; it
+is essential that some base should be present with which the nitric acid
+may combine; when all available base is used up, nitrification ceases.
+
+It appeared of interest to ascertain to what extent nitrification would
+proceed in a dilute solution of urine without the addition of any
+substance save the nitrifying ferment. As urea is converted into ammonium
+carbonate in the first stage of the action of the ferment, a supply of
+salifiable base would at first be present, but would gradually be
+consumed. The result of the experiment showed that only one-half the
+quantity of nitric acid was formed in the simple urine solution as in
+similar solutions containing calcium and sodium carbonate. The
+nitrification of the urine had evidently proceeded until the whole of the
+ammonium had been changed into ammonium nitrate, and the action had then
+ceased. This fact is of practical importance. Sewage will be thoroughly
+nitrified only when a sufficient supply of calcium carbonate, or some
+other base, is available. If, instead of calcium carbonate, a soluble
+alkaline salt is present, the quantity must be small, or nitrification
+will be seriously hindered.
+
+Sodium carbonate begins to have a retarding influence on the commencement
+of nitrification when its amount exceeds 300 milligrammes per liter, and
+up to the present time I have been unable to produce an effective
+nitrification in solutions containing 1.000 gramme per liter.
+
+Sodium hydrogen carbonate hinders far less the commencement of
+nitrification.
+
+Ammonium carbonate, when above a certain amount, also prevents the
+commencement of nitrification. The strongest solution in which
+nitrification has at present commenced contained ammonium carbonate
+equivalent to 368 milligrammes of nitrogen per liter. This hinderance of
+nitrification by the presence of an excess of ammonium carbonate
+effectually prevents the nitrification of strong solutions of urine, in
+which, as already mentioned, ammonium carbonate is the first product of
+fermentation.
+
+Far stronger solutions of ammonium chloride can be nitrified than of
+ammonium carbonate, if the solution of the former salt is supplied with
+calcium carbonate. Nitrification has in fact commenced in chloride of
+ammonium solutions containing more than two grammes of nitrogen per liter.
+
+The details of the recent experiments, some of the results of which we
+have now described, will, it is hoped, shortly appear in the _Journal_ of
+the Chemical Society of London.
+
+Harpenden, July 21.
+
+       *       *       *       *       *
+
+
+
+
+ANILINE DYES IN DRESS MATERIALS.
+
+By Professor CHARLES O'NEILL.
+
+
+Twenty-eight years ago Mr. Perkin discovered the first of the aniline
+dyes. It was the shade of purple called mauve, and the chief agent in its
+production was bichromate of potash. This salt is not actively poisonous,
+and no one thought of attributing injurious properties to materials dyed
+with the aniline mauve. Next in chronological order came magenta red. It
+was first made from aniline by the agency of mercurial salts, and
+afterward by that form of arsenic known to chemists as arsenic acid. The
+fact that this at one time fashionable color was prepared by means of an
+arsenical compound was spread through the country in a very impressive
+manner by the great trial as to whether the patent was valid or not, all
+turning upon the expression in the specification of "dry arsenic acid,"
+and the disputes of scientists whether this expression meant arsenic acid
+with or without water. The public mind had been for some time previously
+exercised and alarmed by accounts of sickness and debility caused by
+arsenical paper-hangings; it was, therefore, easy for pseudo scientists to
+create an opinion that the magenta dye must be also poisonous, and that
+persons wearing materials dyed with this color were liable to absorb
+arsenic and suffer from its action. Ever since there have been, at
+intervals, statements more or less circumstantial, that individuals have
+suffered from wearing materials dyed with some of the artificial dyes. At
+the present time these statements are emphasized by the exhibition at the
+Healtheries of models of skin diseases said to be actually produced by the
+wearing of dyed garments. Whether it be true or not that any form of skin
+disease has been produced by the wearing of dyed articles of clothing is
+simply a question of evidence, and there is evidence enough to show that
+individuals have experienced ill effects who have worn clothing dyed with
+artificial colors. But, as far as we know, there is an entire want of any
+evidence that will satisfactorily show that the inconvenience suffered by
+wearers of these dyed goods has been owing to the dyeing material. Years
+must elapse before chemists or physicians can hope to become thoroughly
+informed of the physiological action produced by the cutaneous absorption
+of the thousands of new products which the ingenuity and industry of
+technological chemists have made available for the manufacture of colors;
+they are also new to science, most of them very complex in their
+constitution, and so dissimilar to previously studied compounds used by
+the dyer, that it may be said we have nearly everything to learn
+concerning their action upon the human economy. With respect to dyed
+woolen and silk goods it is almost entirely a question as to the innocence
+or otherwise of the coloring matter itself, which in nine cases out of ten
+is an organic body containing no mineral matter of any sort, and not
+requiring the assistance of any mordant to enable it to dye.
+Considerations of arsenic, or antimony, or mercury existing in the dyed
+stuffs are absolutely excluded. In a few cases the dyestuff is a zinc
+compound, and zinc in small traces may possibly be fixed by the material,
+but this metal is not known to be actively noxious. Textiles made from
+fibers of animal origin do not require, and as a rule do not tolerate, the
+addition of any metal in dyeing with the artificial colors, and if the
+manufacture of the color require the use of a metal, such as arsenic,
+which by unskillfulness or carelessness is left in it when delivered to
+the dyer, the tendency of the animal fiber is to reject it.
+
+But the case with regard to textiles made from vegetables fibers is quite
+different; upon materials made from cotton, flax, jute, or other fiber of
+the vegetable kingdom, the new aniline colors cannot be fixed without the
+assistance of other bodies acting the part of mordants. Some of these
+bodies are actively poisonous in their nature, and introduce a possible
+element of danger to the wearer of the dyed article. For many years,
+almost the only method of dyeing cotton goods with the aniline colors
+consisted in a preliminary steeping in sumac or tannic acid, followed by a
+passage in some suitable compound of tin, and subsequent dyeing in the
+coloring matter. Sumac and tin have been used for two hundred years or
+more as the dyer's basis for a considerable number of shades of color from
+old dye-stuffs; there never has been the least suspicion that there was
+anything hurtful in colors so dyed. Sumac or tannic acid, in combination
+with alumina, may be held to be equally inoffensive; now it is a fact that
+the great bulk of cotton goods are dyed with the aniline colors by the
+agency of these harmless chemicals. But of late years the dyers of certain
+goods, and the calico printers generally, have found an advantage in the
+use of tartar emetic, and other compounds of antimony, to fix aniline
+colors; besides this, some colors are fixed in calico printing by means of
+an arsenical alumina mordant; it need not be mentioned that antimony, as
+well as arsenic, is, when administered internally, an active poison in
+even small quantities, and that externally both are injurious under
+certain conditions. An alarmist would require nothing further than this
+statement to feel himself justified in attributing everything bad to
+fabrics so colored; but the practical dyer or calico printer knows that
+though he employs these poisonous bodies in his business, and that some
+portion of them does actually accompany the dyed material in its finished
+state, not only is the quantity excessively small, but that it is in such
+a state of combination as to be completely inert and innoxious. In the
+case of tartar emetic, it is the tannate of antimony which remains upon
+the cloth, a compound of considerable stability, and almost perfectly
+insoluble in water; in the case of a few colors fixed by the arsenical
+alumina mordant, the arsenic is in an insoluble state of combination with
+the alumina, in fact, the poisons are in the presence of their antidotes,
+and not even the most scrupulous manufacturer has any fear that he is
+turning out goods which can be hurtful to the wearer. Persons quite
+unacquainted with the process of dyeing are apt to think that goods are
+dyed by simply immersing them in a colored liquid and then drying them
+with all the color on them and all that the color contains; they do not
+know that in all usual cases of dyeing a careful washing in a plentiful
+supply of water is the final process in the dye-house, and that nothing
+remains upon the cloth which can be washed out by water, the color being
+retained by a sort of attraction or affinity between it and the fiber, or
+mordant on the fiber. Dyeing is not like painting or even the printing or
+staining of paper for hangings, where the vehicle and color in its
+entirety is applied and remains. It follows, therefore, that many
+chemicals used in dyeing have only a transitory use, and are washed away
+completely--such as oil of vitriol, much used in woolen dyeing--and that
+of others only a very minute quantity is finally left on the cloth, as is
+the case in antimony and arsenic in cotton dyeing and printing.
+
+There is evidently among working dyers, as among all other classes, an
+unknown amount of carelessness, ignorance, and stupidity, from which
+employers are constantly suffering in the shape of spoiled colors and
+rotted cloth. It is not for us to say that the public may not at times
+have to suffer also from neglect of the most common treatments which
+should remove injurious matters from dyed goods; what can be said is, that
+if the dyeing processes for aniline colors be followed out with ordinary
+care and intelligence, it is extremely improbable that anything left in
+the material should be injurious to human health.--_Manchester Textile
+Recorder._
+
+       *       *       *       *       *
+
+
+
+
+CASE OF RESUSCITATION AND RECOVERY AFTER APPARENT DEATH BY HANGING.
+
+By ERNEST W. WHITE, M.B. Lond., M.R.C.P., Senior Assistant Medical Officer
+to the Kent Lunatic Asylum; Associate, Late Scholar, of King's College,
+London.
+
+
+The following case, from its hopelessness at the outset, yet ultimate
+recovery under the duly recognized forms of treatment, is of such interest
+as to demand publicity, and will afford encouragement to others in moments
+of doubt.
+
+M.A. S----, aged fifty-three, was admitted into the Kent Lunatic Asylum at
+Chartham on Oct. 3, 1882, suffering from melancholia, the duration of
+which was stated to have been three months. She had several times
+attempted suicide by drowning and strangulation. She was on admission
+ordered a mixture containing morphia and ether thrice daily, to allay her
+distress. On Oct. 10 she attempted suicide by tying a stocking, which she
+had secreted about her person, round her neck. Shortly afterward, with
+similar intent, she threw herself downstairs. On Jan. 4, 1883, she
+attempted to strangle herself with her apron. On the 30th of November
+following, at 4 P.M. she evaded the attendants, and made her way to the
+bath-room of of No. 1 ward, the door of which had been left unfastened by
+an attendant. She then suspended herself from a ladder there by means of
+portions of her dress and underclothing tied together. A patient of No. 1
+ward discovered her suspended from the ladder eight minutes after she had
+last seen her in the adjoining watercloset, and gave the alarm.
+
+The woman was quickly cut down, and the medical officers summoned. In the
+interval cold affusion was resorted to by the attendant in charge, but the
+patient was to all appearances dead. The junior assistant medical officer,
+Mr. J. Reynolds Salter, M.B. Lond., arrived after about three minutes, and
+at once resorted to artificial respiration by the Silvester method. A
+minute or so later the medical superintendent and myself joined him. At
+this time the condition of the patient was as follows: The face presented
+the appearance known as facies hippocratica: the eyeballs were prominent,
+the corneæ glassy, the pupils widely dilated, not acting to light, and
+there was no reflex action of the conjunctivæ; the lips were livid, the
+tongue tumefied, but pallid, the skin ashy pale, the cutaneous tissues
+apparently devoid of elasticity. There was an oblique depressed mark on
+the neck, more evident on the left side; the small veins and capillaries
+of the surface of the body were turgid with coagulating blood the surface
+temperature was extremely low. She was pulseless at the wrists and
+temples. There was no definite beat of the heart recognizable by the
+stethoscope.
+
+There was absolute cessation of all natural respiratory efforts, complete
+unconsciousness, total abolition of reflex action and motion, and
+galvanism with the ordinary magneto-electric machine failed to induce
+muscular contractions. The urine and fæces had been passed involuntarily
+during or immediately subsequent to the act of suspension. As the
+stethoscope revealed that but a small amount of air entered the lungs with
+each artificial inspiration, the tongue was at once drawn well forward,
+and retained in that position by an assistant, with the result that air
+then penetrated to the smaller bronchi. Inspiration and expiration were
+artificially imitated about ten times to the minute. In performing
+expiration the chest was thoroughly compressed. The lower extremities were
+raised, and manual centripetal frictions freely applied. In the intervals
+of these applications warmth to the extremities was resorted to.
+
+About ten minutes from the commencement of artificial respiration we
+noticed a single weak spasmodic contraction of the diaphragm, the feeblest
+possible effort at natural respiration. Simultaneously, very distant weak
+reduplicated cardiac pulsations, numbering about 150 to the minute, became
+evident to the stethoscope. The reduplication implied that the two sides
+of the heart were not acting synchronously, owing to obstruction to the
+pulmonary circulation induced by the asphyxiated state. Artificial
+respiration was steadily maintained, and during the next half hour
+spasmodic contractions of the diaphragm occurred at gradually diminishing
+intervals, from once in three minutes to three or four times a minute.
+
+These natural efforts were artificially aided as far as possible. At 5:45
+P.M. natural respiration was fairly though insufficiently established, the
+skin began to lose its deadly hue, and titillation of the fauces caused
+weak reflex contractions. Flagellation with wet towels was now freely
+resorted to, and immediately the natural efforts at respiration were
+increased to twice their previous number. The administration of a little
+brandy and water by the mouth failed, as the liquid entered the larynx.
+Ammonia was applied to the nostrils, and the surface temperature was
+increased by warm applications and clothing. At 6 P.M. artificial
+respiration was no longer necessary. The heart sounds then numbered 140 to
+the minute, the right and left heart still acting separately. A very small
+radial pulse could also be felt. At 6:45 P.M. the woman was put to bed,
+warmth of surface maintained, and hot coffee and beef-tea given in small
+quantities.
+
+Great restlessness and jactitation set in with the renewal of the
+circulation in the extremities. An enema of two ounces of strong beef-tea
+was administered at 10 P.M. The amount of organic effluvium thrown off by
+the lungs on the re-establishment of respiration was very great and
+tainted the atmosphere of the room and adjoining ward. The pupils,
+previously widely dilated, began to contract to light at 11 P.M. Imperfect
+consciousness returned at 5 P.M. the following day (Dec. 1), and about an
+hour later she vomited the contents of the stomach (bread, etc., taken on
+Nov. 30). Small quantities of beef-tea were given by the mouth during the
+night. At 9 A.M. air entered the lungs freely, and there were no symptoms
+of pulmonary engorgement beyond slight basic hypostasis; the pulse
+remained at 140, and the heart sounds reduplicated; she was semiconscious,
+very drowsy, in a state of mental torpor, with confused ideas when roused,
+and she complained of rheumatic-like pains all over her.
+
+The temperature was 100.2°; the facial expression more natural; the tongue
+remained somewhat swollen and sore; she was no longer restless; she took
+tea, beef-tea, milk, etc., well; the functions of the secreting organs
+were being restored; she perspired freely; had micturated; the mucous
+membrane of the mouth was moist, and there was a tendency to tears without
+corresponding mental depression. The patient was ordered a mixture of
+ether and digitalis every four hours. On December 2 the pulse was 136, and
+the heart sounds reduplicated. The following day she was given bromide of
+potassium in place of the ether in the digitalis mixture. On the 4th the
+pulse was 126; reduplication gone. On the 6th the pulse was 82, and the
+temperature fell with the pulse rate. She was well enough to get into the
+ward for a few hours. Her memory, especially for recent events, was at
+that time greatly impaired. On the 12th she still complained of muscular
+pains like those of rheumatism. Apart from that, she was enjoying good
+bodily health.
+
+A curious fact in connection with this case is that since this attempt at
+suicide she has steadily improved mentally, has lost her delusions, is
+cheerful, and employs herself usefully with her needle. She converses
+rationally, and tells me she recollects the impulse by which she was led
+to hang herself, and remembers the act of suspension; but from that time
+her memory is a blank, until two days subsequently, when her husband came
+to see her, and when she expressed great grief at having been guilty of
+such a deed. Her bodily health is now (June 30, 1884) more robust than
+formerly, and she is on the road to mental convalescence.
+
+_Remarks._--The successful issue of this case leads me to draw the
+following inferences: 1. That in cases of suspended animation similar to
+the above there is no symptom by which apparent can be distinguished from
+real death. 2. That in artificial respiration alone do we possess the
+means of restoring animation when life is apparently extinct from
+asphyxia, and that, with the tongue drawn well forward and retained there
+by the hand or an elastic band, the Silvester method is complete and
+effective. 3. That artificial respiration may be necessary for two hours
+or more before the restoration of adequate natural efforts, and that the
+performance of the movements ten times to the minute is amply sufficient,
+and produces a better result than a more rapid rate. 4. That galvanism,
+ammonia to the nostrils, cold affusion, and stimulants by the mouth are
+practically useless in the early stage. 5. That on the re-establishment of
+the reflex function we possess a powerful auxiliary agent in flagellation
+with wet towels, etc. 6. That centripetal surface frictions and the
+restoration of the body temperature by warm applications aid recovery. 7.
+That the heart, if free from organic disease, has great power of
+overcoming the distention of its right cavities and the obstruction to the
+pulmonary circulation, although its action may for a time be seriously
+deranged, as evidenced by reduplication of its sounds. 8. That when the
+heart's action remains excessively feeble, and the right and left heart
+fail to contract synchronously, it would be justifiable to open the
+external jugular vein. 9. That during recovery the lungs are heavily taxed
+in purifying the vitiated blood, as shown by the excessive amount of
+organic impurities exhaled. 10. That restlessness and jactitation
+accompany the restoration of nerve function, and that vomiting occurs with
+returning consciousness. 11. That pains like those of rheumatism are
+complained of for some days subsequently, these probably resulting from
+the sudden arrest of nutrition in the muscles.
+
+Chartham, near Canterbury.
+
+--_Lancet._
+
+       *       *       *       *       *
+
+
+
+
+THE INVENTORS' INSTITUTE.
+
+
+The twenty-second session of the Inventors' Institute was opened on
+October 27, the chair being taken by Vice-Admiral J.H. Selwyn, one of the
+vice-presidents, at the rooms of the institute, Lonsdale Chambers, 27
+Chancery Lane, London. The chairman, in delivering the inaugural address,
+said that in the absence of their president, the Duke of Manchester, it
+became his duty to open the session of 1885. The institute having been
+established in 1862, this was their twenty-second anniversary. At the time
+of its establishment a greater number of members were rapidly enrolled
+than they could now reckon, although a large number had joined since the
+commencement of the present year. In 1862 a considerable amount of
+enthusiasm on the part of inventors had arisen, from the fact that at that
+time the leading journals had advocated the views of certain manufacturers
+as to sweeping away the patent laws, enacted anew in 1852, and with them
+the sole protection of the inventive talent and industry of the nation.
+This naturally caused much excitement and interest among those chiefly
+concerned, and a very numerous body of gentlemen associated themselves
+together and formed an institute for the purpose mainly of resisting the
+aggression and inculcating views more in accordance with true principles,
+as well as for explaining what were the true relations of inventive genius
+to the welfare of the state. He hoped to be able to show strong reasons
+for this action, and for energetically following it up in the future.
+Although on that evening there were many visitors present besides the
+members of the institute, yet he thought the subject could be shown to be
+of such national importance that it might justly engage the attention of
+any assembly of Englishmen, to whatever mode of thought they might belong.
+The institute had persistently done its work ever since its formation.
+Sometimes it had failed to make itself heard, at others it had been more
+successful in so doing; but the net result of its labors--and he did not
+fear to claim it as mainly due to those labors--had been to propagate and
+spread abroad a fact and a feeling entirely opposed to the false doctrines
+previously current on the subject, namely, that among our most valuable
+laws were those which could excite the intelligence and reward the labors
+of the inventors of all nations. There were still those who wished to see
+the patent laws swept away, but their numbers had dwindled into a
+miserable minority, composed mainly of manufacturers who were so curiously
+short-sighted as not to see that all improvement in manufactures must come
+from inventive talent, or those who, still more blind, could not perceive
+that property created by brains was certainly not a monopoly, and deserves
+protection quite as much as any other form of possession, in order that it
+may be developed by capital. He need scarcely waste time in pointing out
+the fallacy of refusing to pay for the seed corn of industrial pursuits,
+for that fallacy, bit by bit, had been completely swept away, and last
+year the labors of the institute had been so far crowned with success that
+the President of the Board of Trade, in his place in Parliament, announced
+his conviction that "inventors were the creators of trade, and ought to be
+encouraged and not repressed." Such a conviction, forced home in such a
+quarter, ought to have produced a great and beneficial change in the
+legislation on the subject, and the hopes of inventors were that this
+would surely be the case; but when the bill appeared these hopes were
+considerably depressed, and now, after a year's experience of the working
+of the changed law, scarcely any benefit appears to have been obtained,
+beyond the meager concession that the heavy payments demanded, for an
+English patent may be made in installments instead of lump sums. Against
+this infinitesimal concession had to be set a number of disabilities which
+did not formerly exist, such as compulsory licenses, which disinclined the
+capitalist to invest in inventions, attempts to assimilate the provisional
+specification to the complete, or to restrict the latter within the terms
+of the former, attempts to separate the parts of an invention, and thus
+increase the number of patents required to protect it, and many other
+minor annoyances which would take too much time to explain fully. It was
+true that there was some extension of the time for payment--some such
+locus penitentiæ as would be accorded to any debtor by any creditor in the
+hope of getting the assets; but the promised spirit of encouragement to
+inventors was not to be found in the bill; it was still a boon which must
+be earnestly sought by the institute.
+
+He had said that the concessions granted were almost infinitesimal, yet a
+result had been obtained, surprisingly confirmatory of the views always
+advocated by the institute as to the potentiality of the inventive talent
+of this nation were it released from its shackles. While in former years
+the highest number of patents taken out had slowly risen to the number of
+five to six thousand per annum, in the year now expiring it had bounded to
+more than three times five thousand--had at one leap reached an equality
+with the patents of the United States, where only £4 ($20) was paid for a
+patent for seventeen years, instead of £175, as in Great Britain, for a
+term of fourteen years. If in the future we could hope to persuade the
+legislators to be content with no heavier tax than in the United States
+had yielded a heavy surplus over expenses of a well-conducted Patent
+Office, he did not fear to assert that the number of patents taken out in
+this country would again be trebled, and that trade and industry would be
+correspondingly animated and developed. The result of the wiser patent law
+of the United States had been to flood our markets with well-manufactured
+yet cheap articles from that country which might have been equally well
+made by our artisans at home had invention not been subject to such heavy
+restrictions, and had technical skill been equally sure of its reward.
+
+The business of the institute in the future was not to rest satisfied with
+the proposition of Mr. Chamberlain, but to lead him or his successors
+forward by logical and legitimate means toward the necessary corollary of
+that proposition. If inventors were indeed the creators of trade, then the
+President of the Board of Trade was bound to see, not only that they were
+not prevented from creating trade, but that they received every facility
+in performing their work. Hence all exertions should be used to convince
+the Chancellor of the Exchequer that a less tax may produce a greater
+income: to persuade the legal authorities that this description of
+property, of all others, most deserves the protection of the law.
+Inherited direct from the Giver of all good gifts, no person had been
+dispossessed of anything he previously owned, and the wealth of humanity
+might be indefinitely increased by means of it. Not many mighty, not many
+noble, received this gift, but it was the inexhaustible heritage of the
+humble, it was the rich reward of the intelligent of all races that
+peopled the earth. To whomsoever given, this gift was intended to
+contribute to the health and the wealth of the human race, for the
+bringing into existence new products, for their utilization for the
+encouragement of the general intelligence of the nations, and for the
+lightening of the burdens of the poor. It would also cause technical
+education to be more highly valued as a means to an end--for true
+inventive genius was never so likely to succeed as when it passed from the
+summit of the known to the confines of the possible, when, having learnt
+and appreciated what predecessors had accomplished, it went earnestly to
+work to solve the next problem, to remove the next obstacle on the path
+which to them had proved insurmountable.
+
+More beneficial than any other change whatever in our legislation would be
+a full and cordial recognition, a complete and efficient protection, of
+property created by thought. Then the humblest individual in the land
+might have confidence that he could call into existence property not
+inferior in value to that of the richest landowner, the most successful
+merchant, or the most wealthy manufacturer, in the whole world. As an
+instance of this Admiral Selwyn mentioned two prominent cases arising out
+of the pursuit of two widely differing branches of knowledge, in the one
+case by an outsider, in the other by a specialist. He referred to Sir H.
+Bessemer, one of his valued colleagues in the vice-presidency of the
+institute, and Mr. Perkins, the discoverer of aniline dyes. In each of
+these instances, whatever might have been the results to the inventors,
+and he hoped they had been satisfactory, a sum which might be estimated at
+twenty millions sterling annually, constantly on the increase, and never
+before existing, had been added to the income-tax-paying wealth of the
+country. With such a result arising from the development of only two
+inventions, he thought it would be seen that he must be a most ignorant,
+foolish, or obstinate Chancellor of the Exchequer who would refuse to
+allow such property to be created by requiring heavy preliminary payments,
+or in any way discourage or fail to encourage to the utmost of his power
+the creation of property which was capable of producing such a result--a
+result which he would in vain seek for did he rely on landed property
+alone, since this, in the hands of whomsoever it might be, never could
+largely increase in extent, and was subject at this moment to serious
+depreciation in tax-paying power.
+
+The exertion of intelligence, combined with a sense of security in its
+pecuniary results, was in itself opposed to loose notions of proprietary
+rights, and tended to diminish that coveting of neighbors' goods which was
+the fertile source of vice and crime, and which was capable of breaking
+down the strongest and most wealthy community if indulged, till at last
+society was resolved into its elements, and when nothing else was left as
+property, man, the savage, coveted the scalp of his fellow man, and
+triumphed over a lock of hair torn from his bleeding skull.
+
+Invention was an ennobling pursuit, and was, even among those who were not
+also handworkers, a means of employment which never left dull or idle
+hours, while to the handworker it meant more, for it offered the most
+ready means of rising among his fellows, and, where invention received
+proper protection, of securing a competence for old age or ill health. Not
+only, as he had before said, did the results of invention cause no loss to
+any other individual, unless by displacing inferior methods of working,
+but in most instances some distinct benefit arose to the whole human race,
+and unless this was the case the patented invention failed to obtain
+recognition, soon died out, and left the field clear for others to occupy.
+
+He regretted that so few results had been obtained from the Patent Bill of
+last year, but he would briefly refer to some of the changes thought
+desirable by inventors and by the council of the institute.
+
+No one could deem it desirable, it could scarcely be thought reasonable,
+that an Englishman who was called upon to pay in the United States £7 for
+a valid patent for seventeen years should be still obliged in his own
+country to pay £175 for a less term of a patent which does not convey
+anything but a right to go to law. It was also not reasonable to pretend
+by a deed to convey a proprietary right while reserving the power to grant
+compulsory licenses, which must tend to destroy the value of such
+proprietary right.
+
+It was a reproach to legislative perspicacity that the grantee of a patent
+should be obliged to accept the view of the state, the grantor, as to the
+value of the invention to the nation, and also that any other method of
+proceeding to upset a patent, once granted, should be allowed than a suit
+for revocation to the crown, on the ground of error, such revocation if
+obtained not to prejudice the granting anew, with the old date, of a valid
+patent for the parts of the invention which are not proved to be
+anticipated at the trial. There are many other points which could not be
+referred to on the present occasion, but he might say that the duty of the
+council would be to press them forward until the capitalist could consider
+patented property at least as sound an investment as any other. So might
+the wealth of the nation be largely increased, and the sense of justice
+between man and man be more fully inculcated. In the United States
+inventors were able at once to secure the favorable attention of
+capitalists, because there the whole business of the Patent Office was to
+assist the inventor to obtain a valid--and, as far as possible, an
+indisputable--patent.
+
+Even so small an article as a pair of pliers, one of the most familiar of
+tools, had been proved to be capable of patented improvement. Formerly
+these were always made to open and close at an angle which precluded their
+holding any object grasped by them with the desirable rigidity. A clever
+workman invented a means of producing this effect by the application of a
+parallel motion. He probably went to the office at Washington, was
+referred to a certain room in a certain corridor, and there found a
+gentleman whose business it was to know all about the patents for such
+tools. By his aid he eliminated from his patent all anticipatory matter,
+and issued from the office with a valid patent, which, developed by
+capital, had supplied all the trades which employ such instruments with a
+better means of accomplishing their work, had employed capital and labor
+with remunerative results in producing the pliers, and had added one more
+to the little things which create trade for his country.
+
+This was a typical instance of the way in which invention was encouraged
+in America. Why should it be otherwise here? For many years literary
+property had received a protection which was yet to be desired for
+patented invention. Not only for fourteen years, but for the duration of a
+man's life, was that kind of brain property protected, and even after his
+death his heirs still continued to derive benefit from it. Should a
+romance or a poem be deemed more worthy of reward than the labors of those
+inventors to whom he had referred, and which certainly produced far
+greater and more abiding advantage to the nation? To secure a due
+appreciation of the whole importance of invention, no other means could be
+adopted than that which the institute had been formed to secure, namely,
+the union of inventors, not only of one nation, but of the whole world.
+The international character of the subject had been recognized by the
+institute, and they had never neglected any opportunities of pressing that
+view of the subject, which had at last obtained some recognition from our
+government.
+
+No great result could, however, be expected from a congress where
+inventors, not lawyers or patent agents, still less officials trained in a
+vicious routine, formed the majority. It might be hoped that next year
+there would arise an opportunity for such a congress, and that the
+institute would do its best to improve the occasion. There never had been
+a time when England more required the creation of new industries. Our
+agriculturists had signally failed to hold their own in the face of
+unlimited competition, and the food of the nation no longer came from
+within. But if that were the case, then some means must be found of paying
+for the food imported from abroad, and this could only be done by constant
+improvement in manufactures, or some change by which we might sell some of
+our other productions at a profit if the food could not be produced but at
+a loss. Here invention might fitly be called to aid, but could only
+respond if all restrictions were removed and every facility granted.
+
+Capital must be induced to consider that home investments are more
+remunerative and not less secure than any others, and this could only be
+done by adding to the security of the property proposed for investment. He
+had referred to the unlimited nature of the property created by invention,
+and they would infer that if properly protected there was equally no limit
+to the capital that could be profitably employed in developing such
+property. The institute did not exist solely or even mainly for the
+purpose of advocating the claims of inventors to consideration, either
+individually or collectively, but for the great object of forcing home
+upon the convictions of the people the fact that at the very foundation of
+the wealth and prosperity of every nation lies the intelligence, the
+skill, the honesty, and the self-denial of its sons.
+
+If, when these were exercised, for want of wise legislation such virtues
+failed to secure their due reward, they sought a more genial clime, and
+that nation which had undervalued them sank to rise no more; or, if the
+error were acknowledged, and too late the course was reversed, found
+itself already outstripped in the race of progress, and could slowly, if
+ever, regain its lost position. Finally he urged the inventors of England
+to rally round the institution in all their strength, and thus secure the
+objects of which he had striven, however feebly, to point out the
+importance. If they did so, this institution would take a rank second to
+no other in the empire: and while acknowledging that the interests of the
+inventor must always be subordinate to the welfare of the state, he
+asserted that the two were inseparable, and that in no other way could the
+latter and principal result be so completely secured as by according a due
+consideration to the former.
+
+       *       *       *       *       *
+
+
+
+
+THE NEW CENTRAL SCHOOL AT PARIS.
+
+
+We present herewith, from _L'Illustration_, views of the amphitheater, and
+first and second year laboratories of the new Central School at Paris.
+
+[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
+
+The amphitheater does not perceptibly differ from those of other schools.
+It consists of a semicircle provided with rows of benches, one above
+another, upon which the pupils sit while listening to lectures and taking
+notes thereof. Several blackboards, actuated by hydraulic motors, serve
+for demonstration by the professor, who, if need be, will be enabled,
+thanks to the electricity and gas put within his reach, to perform
+experiments of various kinds. Electricity is brought to him by wires, just
+as water and gas are by pipes. It will always be possible for him to
+support the theory that he is explaining by experiments which facilitate
+the comprehension of it by the pupils. The amphitheater is likewise
+provided with a motor which furnishes the professor with power whenever he
+has recourse to a mechanical application.
+
+It will not be possible for the pupils to have their attention distracted
+by what is going on outside of the amphitheater, since the architect has
+taken the precaution to use ground glass in the windows.
+
+[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
+
+As regards the laboratories, it is allowable to say that they constitute
+the first great school of experimental chemistry in France. The first year
+laboratory consists of a series of tables, provided with evaporating
+hoods, at which a series of pupils will study general chemistry
+experimentally. Electricity, and gas and water cocks are within reach of
+each operator, and all the deleterious emanations from the acids that are
+used or are produced in studying a body will escape through the hoods.
+
+The third year laboratory is designed for making commercial analyses.
+These latter are made by either dry or wet way. The first method employs
+water chiefly as a vehicle, and alkaline solutions as reagents. The second
+employs reagents in a dry state, and the action of which requires lamp and
+furnace heat. The furnaces employed in the new school are like those
+almost exclusively used industrially for the analysis of ores. The tables
+upon which analyses by dry way are made are large enough to allow sixteen
+pupils to work.
+
+[Illustration: THE NEW CENTRAL SCHOOL AT PARIS.]
+
+Analyses by wet way are made upon tables, with various sorts of vessels.
+Along with water, gas, and electricity, the pupils have at their disposal
+a faucet from whence they may draw the hydrosulphuric acid which is so
+constantly used in laboratory operations.
+
+The architect of the new school is Mr. Denfer.
+
+       *       *       *       *       *
+
+
+
+
+[NATURE.]
+
+RESEARCHES ON THE ORIGIN AND LIFE-HISTORIES OF THE LEAST AND LOWEST
+LIVING THINGS.
+
+By Rev. W.H. DALLINGER, LL. D.
+
+
+To all who have familiarized themselves, even cursorily, with modern
+scientific knowledge, it is well known that the mind encounters the
+_infinite_ in the contemplation of minute as well as in the study of vast
+natural phenomena. The farthest limit we have reached, with the most
+gigantic standard of measurement we could well employ, in gauging the
+greatness of the universe, only leaves us with an overwhelming
+consciousness of the awful greatness--the abyss of the infinite--that lies
+beyond, and which our minds can never measure. The indefinite has a limit
+somewhere; but it is not the indefinite, it is the measureless, the
+infinite, that vast extension forces upon our minds. In like manner, the
+immeasurable in minuteness is an inevitable mental sequence from the facts
+and phenomena revealed to us by a study of the _minute_ in nature. The
+practical divisibility of matter disclosed by modern physics may well
+arrest and astonish us. But biology, the science which investigates the
+phenomena of all living things, is in this matter no whit behind. The most
+universally diffused organism in nature, the least in size with which we
+are definitely acquainted, is so small that fifty millions of them could
+lie together in the one-hundredth of an inch square. Yet these definite
+living things have the power of locomotion, of ingestion, of assimilation,
+of excretion, and of enormous multiplication, and the material of which
+the inconceivably minute living speck is made is a highly complex chemical
+compound. We dare not attempt a conception of the minuteness of the
+ultimate atoms that compose the several simple elements that thus
+mysteriously combine to form the complex substance and properties of this
+least and lowliest living thing. But if we could even measure these, as a
+mental necessity, we are urged indefinitely on to a minuteness without
+conceivable limit, in effect, a minuteness that is beyond all finite
+measure or conception. So that, as modern physics and optics have enabled
+us not to conceive merely, but to actually realize, the vastness of
+spatial extension, side by side with subtile tenuity and extreme
+divisibility of matter, so the labor, enthusiasm, and perseverance of
+thirty years, stimulated by the insight of a rare and master mind, and
+aided by lenses of steadily advancing perfection, have enabled the student
+of life-forms not simply to become possessed of an inconceivably broader,
+deeper, and truer knowledge of the great world of visible life, of which
+he himself is a factor, but also to open up and penetrate into a world of
+minute living things so ultimately little that we cannot adequately
+conceive them, which are, nevertheless, perfect in their adaptations and
+wonderful in their histories. These organisms, while they are the least,
+are also the lowliest in nature, and are to our present capacity totally
+devoid of what is known as organic structure, even when scrutinized with
+our most powerful and perfect lenses. Now these organisms lie on the very
+verge and margin of the vast area of what we know as living. They possess
+the essential properties of life, but in their most initial state. And
+their numberless billions, springing every moment into existence wherever
+putrescence appeared, led to the question, How do they originate? Do they
+spring up _de novo_ from the highest point on the area of _not-life_,
+which they touch? Are they, in short, the direct product of some yet
+uncorrelated force in nature, changing the dead, the unorganized, the
+not-living, into definite forms of life? Now this is a profound question,
+and that it is a difficult one there can be no doubt. But that it is a
+question for our laboratories is certain. And after careful and prolonged
+experiment and research the legitimate question to be asked is, Do we find
+that, in our laboratories and in the observed processes of nature now, the
+not-living can be, without the intervention of living things, changed into
+that which lives?
+
+To that question the vast majority of practical biologists answer without
+hesitancy, _No_, we have no facts to justify such a conclusion. Prof.
+Huxley shall represent them. He says: "The properties of living matter
+distinguish it absolutely from all other kinds of things;" and, he
+continues, "the present state of our knowledge furnishes us with no link
+between the living and the not-living." Now let us carefully remember that
+the great doctrine of Charles Darwin has furnished biology with a
+magnificent generalization; one indeed which stands upon so broad a basis
+that great masses of detail and many needful interlocking facts are, of
+necessity, relegated to the quiet workers of the present and the earnest
+laborers of the years to come. But it is a doctrine which cannot be
+shaken. The constant and universal action of variation, the struggle for
+existence, and the "survival of the fittest," few who are competent to
+grasp will have the temerity to doubt. And to many, that lies within it as
+a doctrine, and forms the fibre of its fabric, is the existence of a
+continuity, an unbroken stream of unity running from the base to the apex
+of the entire organic series. The plant and the animal, the lowliest
+organized and the most complex, the minutest and the largest, are related
+to each other so as to constitute one majestic organic whole. Now to this
+splendid continuity practical biology presents no adverse fact. All our
+most recent and most accurate knowledge confirms it. But _the_ question
+is, Does this continuity terminate now in the living series, and is there
+then a break--a sharp, clear discontinuity, and beyond, another realm
+immeasurably less endowed, known as the realm of not-life? or Does what
+has been taken for the clear-cut boundary of the vital area, when more
+deeply searched, reveal the presence of a force at present unknown, which
+changes not-living into the living, and thus makes all nature an unbroken
+sequence and a continuous whole? That this is a great question, a question
+involving large issues, will be seen by all who have familiarized
+themselves with the thought and fact of our times. But we must treat it
+purely as a question of science; it is not a question of _how_ life
+_first_ appeared upon the earth, it is only a question of whether there is
+any natural force _now_ at work building not-living matter into living
+forms. Nor have we to determine whether or not, in the indefinite past,
+the not-vital elements on the earth, at some point of their highest
+activity, were endowed with, or became possessed of, the properties of
+life.
+
+[Illustration: Fig. 1]
+
+On that subject there is no doubt. The elements that compose
+protoplasm--the physical basis of all living things--are the familiar
+elements of the world without life. The mystery of life is not in the
+elements that compose the vital stuff. We know them all, we know their
+properties. The mystery consists _solely_ in _how_ these elements can be
+so combined as _to acquire_ the transcendent properties of life. Moreover,
+to the investigator it is not a question of _by what means_ matter
+dead--without the shimmer of a vital quality--became either slowly or
+suddenly possessed of the properties of life. Enough for us to know that
+whatever the power that wrought the change, that power was competent, as
+the issue proves. But that which calm and patient research has to
+determine is whether matter demonstrably _not living_ can be, without the
+aid of organisms already living, endowed with the properties of life.
+Judged of hastily, and apart from the facts, it may appear to some minds
+that an origin of life from not-life, by sheer physical law, would be a
+great philosophical gain, an indefinitely strong support of the doctrine
+of evolution. If this were so, and, indeed, so far as it is believed to be
+so, it would speak and does speak volumes in favor of the spirit of
+science pervading our age. For although the vast majority of biologists in
+Europe and America accept the doctrine of evolution, they are almost
+unanimous in their refusal to accept as in any sense competent the reputed
+evidence of "spontaneous generation;" which demonstrates, at least, that
+what is sought by our leaders in science is not the mere support of
+hypotheses, cherished though they may be, but the truth, the uncolored
+truth, from nature. But it must be remembered that the present existence
+of what has been called "spontaneous generation," the origin of life _de
+novo_ to-day, by physical law, is by no means required by the doctrine of
+evolution. Prof. Huxley, for example, says: "If all living beings have
+been evolved from pre-existing forms of life, it is enough that a single
+particle of protoplasm should _once_ have appeared upon the globe, as the
+result of no matter what agency; any further independent formation of
+protoplasm would be sheer waste." And why? we may ask. Because one of the
+most marvelous and unique properties of protoplasm, and the living forms
+built out of it, _is the power_ to multiply indefinitely and for ever!
+What need, then, of spontaneous generation? It is certainly true that
+evidence has been adduced purporting to support, if not establish, the
+origin in dead matter of the least and lowest forms of life. But it
+evinces no prejudice to say that it is inefficient. For a moment study the
+facts. The organisms which were used to test the point at issue were those
+known as _septic_. The vast majority of these are inexpressibly minute.
+The smallest of them, indeed, is so small that, as I have said, fifty
+millions of them, if laid in order, would only fill the one-hundredth part
+of a cubic inch. Many are relatively larger, but all are supremely minute.
+Now, these organisms are universally present in enormous numbers, and ever
+rapidly increasing in all moist putrefactions over the surface of the
+globe.
+
+Take an illustration prepared for the purpose, and taken direct from
+nature. A vessel of pure drinking water was taken during the month of July
+at a temperature of 65 deg. F., and into it was dropped a few shreds of
+fish muscle and brain. It was left uncovered for twelve hours; at the end
+of that time a small blunt rod was inserted in the now somewhat opalescent
+water, and a minute drop taken out and properly placed on the microscope,
+and, with a lens just competent to reveal the minutest objects, examined.
+The field of view presented is seen in Fig. 1, A. But--with the exception
+of the dense masses which are known as zoogloea or bacteria, fused
+together in living glue--the whole field was teeming with action; each
+minute organism gyrating in its own path, and darting at every visible
+point. The same fluid was now left for sixteen hours, and once more a
+minute drop was taken and examined with the same lens as before. The field
+presented to the eye is depicted in Fig. 1, B, where it is visible that
+while the original organism persists yet a new organism has arisen in and
+invaded the fluid. It is a relatively long and beautiful spiral form, and
+now the movement in the field is entrancing. The original organism darts
+with its vigor and grace, and rebounds in all directions. But the spiral
+forms revolving on their axes glide like a flight of swallows over the
+ample area of their little sea. Ten hours more elapsed and, without change
+of circumstances, another drop was taken from the now palpably putrescent
+fluid. The result of examination is given in Fig. 1, C, where it will be
+seen that the first organism is still abundant, the spiral organism is
+still present and active, but a new and oval form, not a bacterium, but a
+_monad_, has appeared. And now the intensity of action and beauty of
+movement throughout the field utterly defy description, gyrating, darting,
+spinning, wheeling, rebounding, with the swiftness of the grayling and the
+beauty of the bird. Finally, at the end of another eight to sixteen hours,
+a final "dip" was taken from the fluid, and under the same lens it
+presented as a field what is seen in Fig. 1, D, where the largest of the
+putrefactive organisms has appeared and has even more intense and more
+varied movements than the others. Now the question before us is, "How did
+these organisms arise?" The water was pure; they were not discoverable in
+the fresh muscle of fish. Yet in a dozen hours the vessel of water is
+peopled with hosts of individual forms which no mathematics could number!
+How did they arise? From universally diffused eggs, or from the direct
+physical change of dead matter into living forms? Twelve years ago the
+life-histories of these forms were unknown. We did not know biologically
+how they developed. And yet with this great deficiency it was considered
+by some that their mode of origin could be determined by heat experiments
+on the adult forms. Roughly, the method was this: It was assumed that
+nothing vital could resist the boiling point of water. Fluids, then,
+containing full-grown organisms in enormous multitudes, chiefly bacteria,
+were placed in flasks, and boiled for from five to ten minutes. While they
+were boiling the necks of the flasks was hermetically closed; and the
+flask was allowed to remain unopened for various periods. The reasoning
+was: "Boiling has killed all forms of vitality _in_ the flask; by the
+hermetical sealing nothing living can gain subsequent access to the fluid;
+therefore, if living organisms do appear when the flask is opened, they
+must have arisen in the dead matter _de novo_ by spontaneous generation,
+but if they do never so arise, the probability is that they originate in
+spores or eggs."
+
+Now it must be observed concerning this method of inquiry that it could
+never be final; it is incompetent by deficiency. Its results could never
+be exhaustive until the life-histories of the organisms involved were
+known. And further, although it is a legitimate method of research for
+partial results, and was of necessity employed, yet it requires precise
+and accurate manipulation. A thousand possible errors surround it. It can
+only yield scientific results in the hands of a master in physical
+experiment. And we find that when it has secured the requisite skill, as
+in the hands of Prof. Tyndall, for example, the result has been the
+irresistible deduction that living things have never been seen to
+originate in not-living matter. Then the ground is cleared for the
+strictly biological inquiry, How do they originate? To answer that
+question we must study the life histories of the minutest forms with the
+same continuity and thoroughness with which we study the development of a
+crayfish or a butterfly. The difficulty in the way of this is the extreme
+minuteness of the organisms. We require powerful and perfect lenses for
+the work. Happily during the last fifteen years the improvement in the
+structure of the most powerful lenses has been great indeed. Prior to this
+time there were English lenses that amplified enormously. But an
+enlargement of the image of an object avails nothing, if there be no
+concurrent disclosure of detail. Little is gained by expanding the image
+of an object from the ten-thousandth of an inch to an inch, if there be
+not an equivalent revelation of hidden details. It is in this revealing
+quality, which I shall call _magnification_ as distinct from
+_amplification_, that our recent lenses so brilliantly excel. It is not
+easy to convey to those unfamiliar with objects of extreme minuteness a
+correct idea of what this power is. But at the risk of extreme simplicity,
+and to make the higher reaches of my subject intelligible to all, I would
+fain make this plain.
+
+But to do so I must begin with familiar objects, objects used solely to
+convey good relative ideas of minute dimension. I begin with small objects
+with the actual size of which you are familiar. All of us have taken a
+naked eye view of the sting of the wasp or honey bee; we have a due
+conception of its size. This is the scabbard or sheath which the naked eye
+sees.[3] Within this are two blades terminating in barbed points. The
+point of the scabbard more highly magnified is presented, showing the
+inclosed barbs. One of the barbs, looked at on the barbed edge, is also
+seen. Now these two barbed stings are tubes with an opening in the end of
+the barb. Each is connected with the tube of the sac, C. This Is a
+reservoir of poison, and D is the gland by which it is secreted. Now I
+present this to you, not for its own sake, but simply for the comparison,
+a comparison which struck the earliest microscopists. Here is the scabbard
+carefully rendered. One of the stings is protruded below its point, as in
+the act of stinging; the other is free to show its form. Now the actual
+length of this scabbard in nature was the _one-thirtieth_ of an inch. I
+have taken the point, C, of a fine cambric sewing needle, and broken it
+off to slightly less than the one-thirtieth of an inch, and magnified it
+as the sting is magnified. Now here we obtain an instance of what I mean
+by magnification. The needle point is not merely bigger, unsuspected
+details start into view. The sting is not simply enlarged, but all its
+structure is revealed. Nor can we fail to note that the _finish_ of art
+differs from that of nature. The homogeneous gloss of the needle
+disappears under the fierce scrutiny of the lens, and its delicate point
+becomes furrowed and riven. But Nature's finish reveals no flaw, it
+remains perfect to the last.
+
+[Footnote 3: A magnified image of the bee's sting was projected on the
+screen.]
+
+We may readily amplify this. The butterflies and moths of our native lands
+we all know; most of us have seen their minute eggs. Many are quite
+visible to the unaided eye; others are extremely minute. A gives the egg
+of the small white butterfly;[4] B, that of the small tortoiseshell; C,
+that of the waved umber moth; D, that of the thorn moth; E, that of the
+shark moth; at F we have the delicate egg of the small emerald butterfly,
+and at G an American skipper; and finally, at H, the egg of a moth known
+as mania maura. In all this you see a delicacy of symmetry, structure, and
+carving, not accessible to the eye, but clearly unfolded. We may, from our
+general knowledge, form a correct notion of the average relation in size
+existing between butterflies and their eggs; so that we can compare. Now
+there is a group of extremely minute, insect-like forms that are the
+parasites of birds. Many of them are just plainly visible to the naked
+eye, others are too minute to be clearly seen, and others yet again wholly
+elude the unaided sight. The epizoa generally lodge themselves in various
+parts of the plumage of birds; and almost every group of birds becomes the
+host of some specific or varietal form with distinct adaptations. There is
+here seen a parasite that secretes itself in the inner feathers of the
+peacock, this is a form that attacks the jay, and here is one that
+secretes itself beneath the plumage of the partridge.
+
+[Footnote 4: A series of the eggs of butterflies were then shown, as were
+the objects successively referred to, but not here reproduced.]
+
+Now these minute creatures also deposit eggs. They are placed with
+wonderful instinct in the part of the plumage and the part of the feather
+which will most conserve their safety; and they are either glued or fixed
+by their shape or by their spine in the position in which they shall be
+hatched. I show here a group of the eggs of these minute creatures. I need
+not call your attention to their beauty; it is palpable. But I am fain to
+show you that, subtle and refined as that beauty is, it is clearly brought
+out. The flower-like beauty of the egg of the peacock's parasite, the
+delicate symmetry and subtle carving of the others, simply entrance an
+observer. Note then that it is not merely _enlarged_ specks of form that
+we are beholding, but such true magnifications of the objects as bring out
+all their subtlest details. And it is _this_ quality that must
+characterize our most powerful lenses. I am almost compelled to note in
+passing that the _beauty_ of these delicate and minute objects must not be
+considered _an end_--a purpose--in nature. It is not so. The form is what
+it is because it _must be_ so to serve the end for which the egg is
+formed. There is not a superfluous spine, not a useless petal in the
+floral egg, not an unneeded line of chasing in the decorated shell. It is
+shaped beautifully because its shape is needed. In short, it is Nature's
+method; the identification of beauty and use. But to resume. We may at
+this point continue our illustrations of the analytical power of moderate
+lenses by a beautiful instance. We are indebted to Albert Michael, of the
+Linnean Society of England, for a masterly treatise on a group of acari,
+or _mites_, known as the _oribatidæ_. Many of these he has discovered. The
+one before you is a full grown nymph of what is known as a _palmicinctum_.
+It is deeply interesting as a form; but for us its interest is that it is
+minute, being only a millimeter in length. But it repeatedly casts the
+dorsal skin of the abdomen. Each skin is bordered by a row of exquisite
+scales; and then successive rows of these scales persist, forming a
+protection to the entire organism. Mark then that we not only reveal the
+general form of the nymph, but the lens reveals the true structure of the
+scales, not enlargement merely, but detail. The egg of the organism, still
+more magnified, is also seen.
+
+To vary our examples and still progress. We all know the appearance and
+structure of chalk. The minute foraminifera have, by their accumulated
+tests, mainly built up its enormous masses. But there is another chalk
+known as Barbados earth; it is silicious, and is ultimately composed of
+minute and beautiful skeletons such as those which, enormously magnified,
+you now see. These were the glassy envelopes which protected the living
+speck that dwelt within and built it. They are the minutest of the
+Radiolaria, which peopled in inconceivable multitudes the tertiary oceans;
+and, as they died, their minute skeletons fell down in a continuous rain
+upon the ocean bed, and became cemented into solid rock which geologic
+action has brought to the surface in Barbados and many other parts of the
+earth. If a piece of this earth, the size of a bean, be boiled in dilute
+acid and washed, it will fall into powder, the ultimate grains of which
+are such forms as these which you see. The one before you is an instance
+of exquisite refinement of detail. The form from which the drawing of the
+magnified image was made was extremely small--a mere white speck in the
+strongest light upon a black ground. But you observe it is not a speck of
+form merely enlarged. It is not merely beauty of outline made bigger. But
+there is--as in the delicate group you now see--a perfect opening up of
+otherwise absolutely invisible details. We may strengthen this evidence in
+favor of the analytical power of our higher lenses by one more _familiar_
+example, and then advance to the most striking illustration of this power
+which our most perfect and powerful lenses can afford. I fear that may be
+taking too much for granted to assume that every one in an audience like
+this has seen a human flea! Most, however, will have a dim recollection or
+suggestive instinct as to its size in nature. Nothing striking is revealed
+by this amount of magnification excepting the existence of breathing pores
+or spiracles along the scale armor of its body. But there is a trace of
+structure in the terminal ring of the exo-skeleton which we cannot clearly
+define, and of which we may desire to know more. This can be done only by
+the use of far higher powers.
+
+To effect this, we must carefully cut off this delicate structure, and so
+prepare it that we may employ upon it the first of a series of our highest
+powers. The result of that examination is given here.[5] You see that the
+whole organ has a distinct form and border, and that its carefully carved
+surface gives origin to wheel-like areolæ which form the bases of delicate
+hairs. The function of this organ is really unknown. It is known from its
+position as the _pygidium_; and from the extreme sensitiveness of the
+hairs to the slightest aerial movement, may be a tactile organ warning of
+the approach of enemies; the eyes have no power to see. But we have not
+reached the ultimate accessible structure of this organ. If we place a
+portion of the surface under one of the finest of our most powerful
+lenses, this will be the result.[6] Now, without discussing the real
+optical or anatomical value of this result as it stands, what I desire to
+remind you of is:
+
+1. The natural size of the flea.
+
+2. The increase of knowledge gained by its general enlargement.
+
+3. The relation in size between the flea and its pygidium.
+
+4. The manner in which our lenses reveal its structure, not merely amplify
+its form.
+
+[Footnote 5: The pygidium of the flea, very highly magnified, was here
+shown.]
+
+[Footnote 6: An illustration of the pygidium structure seen with
+one-thirty-fifth immersion was given.]
+
+Now with these simple and yet needful preliminaries you will be able to
+follow me in a careful study of the least, the very lowliest and smallest,
+of all living things. It lies on the very verge of our present powers of
+optical aid, and what we know concerning it will convince you that we are
+prepared with competent skill to attack the problem of the life-histories
+of the smallest living forms. The group to which the subject of our
+present study belongs is the bacteria. They are primarily staff-like
+organisms of extreme minuteness, but may be straight, or bent, or curved,
+or spiral, or twisted rods. This entire projection is drawn on glass, with
+_camera lucida_, each object being magnified 2,000 diameters, that is to
+say, 4,000,000 of times in area. Yet the entire drawing is made upon an
+area of not quite 3 inches in diameter, and afterward projected here. The
+objects therefore are all equally magnified, and their relative sizes may
+be seen. The giant of the series is known as _Spirillum volutans;_ and you
+will see that the representative species given become less and less in
+size until we reach the smallest of all the definite forms, and known to
+science as _Bacterium termo_.
+
+Now within given limits this organism varies in size, but if a fair
+average be taken its size is such that 50,000,000 laid in order would only
+fill the hundredth of a cubic inch. Now the majority of these forms _move_
+with rapidity and grace in the fluids they inhabit. But how? By what
+means? By looking at the largest form of this group, you will see that it
+is provided with two delicate fibers, one at each end. Ehrenberg and
+others strongly suspected their existence, and we were enabled, with more
+perfect lenses, to _demonstrate_ their presence some twelve years ago.
+They are actually the swimming organs of this Spirillum. The fluid is
+lashed rhythmically by these fibers, and a spiral movement of the utmost
+grace results. Then do the intermediate forms that move also possess these
+flagella, and does this least form in nature, viz., _Bacterium termo_,
+accomplish its bounding and rebounding movements in the same way? Yes! by
+a series of resolute efforts, in using a new battery of lenses--the finest
+that at that time had ever been put into the hands of man--I was enabled
+to show in succession that each motile form of Bacterium up to _B.
+lineola_ accomplished its movements by fibers or flagella; and that in the
+act of self-division, constantly taking place, a new fiber was drawn out
+for each half before separation.
+
+But the point of difficulty was _B. termo_. The demonstration of its
+flagella was a task of difficulty which only patient purpose could
+conquer. But by the use of our new lenses, and special illumination we--my
+colleague and I--were enabled to demonstrate clearly a flagellum at each
+end of this least of living organisms, as you see, and by the rapid
+lashing of the fluid, alternately or together, with these flagella, the
+powerful, rapid, and graceful movements of this smallest known living
+thing are accomplished. Of course these fibers are inconceivably
+fine--indeed for this very reason it was desirable, if possible, to
+_measure_ it, to discover its actual thickness. We all know that, both for
+the telescope and the microscope, beautiful apparatus are made for
+measuring minute magnified details. But unfortunately no instrument
+manufactured was delicate enough to measure _directly_ this fiber. If it
+were measured it must be by an indirect progress, which I accomplished
+thus: The diameter of the body of _B. termo_, _i.e._, from; side to side,
+may in different forms vary from the 1/20000 to the 1/50000 of an inch.
+_That_ is a measurement which we may easily make directly with a
+micrometer. Haying ascertained this, I determined to discover the ratio of
+thickness between the body of the Bacterium and its flagellum--that is to
+say, to discover how many of the flagella laid side by side would make up
+the width of the body.
+
+I proceeded thus: This is a complicated microscope placed on a tripod, so
+arranged that it may be conveniently worked upright. There is a special
+instrument for centering and illuminating. On the stage of the instrument,
+the Bacterium with its flagellum in distinct focus is placed. Instead of
+the simple eyepiece, _camera lucida_ is placed upon it. This instrument is
+so constructed that it appears to throw the image of the object upon the
+white sheet of paper on the small table at the right hand where the
+drawing is made, at the, same time that it enables the same eye to see
+the pencil and the right hand. In this way I made a careful drawing of _B.
+termo_ and its flagellum, magnified 5,000 diameters. Here is a projection
+of the drawing made. But I subsequently avoided paper, and used under the
+camera most carefully prepared surface of ground glass. When the drawing
+was made I placed on the drawing a drop of Canada balsam, and covered it
+with a circle of thin glass, just like any other microscopic mounted
+object. This is a micro-slide so prepared. Now you can see that I only
+have to lay this on the stage of a microscope, make it an object for a low
+power, and use a screw micrometer to find how many flagella go to the
+making of a body. The result is given in the figure; you see that ten
+flagella would fill the area occupied by the diameter of the body.
+
+In the case chosen the body was the 1/20,400 of an inch wide, and
+therefore, when divided by ten, gave for the flagellum a thickness of the
+1/204,000 of an English inch. In the end I made fifty separate drawings
+with four separate lenses. I averaged the result in each fifty, and then
+took the average of the total of 200, and the mean value of the width of
+the flagellum was the 1/204,700 of an English inch. It will be seen, then,
+that we are possessed of instruments which, when competently used, will
+enable us to study the life-histories of the putrefactive organisms,
+although they are the minutest forms of life. I have stated that they were
+the inevitable accompaniments of putrescence and decay. You learned from a
+previous illustration the general appearance of the Bacteria; they are the
+earliest to appear whenever putrefaction shows itself. In fact the pioneer
+is this--the ubiquitous _Bacterium termo._ The order of succession of the
+other forms is by no means certain. But whenever a high stage of
+decomposition is reached, a group of forms represented by these three will
+swarm the fluid. These are the Monads, they are strictly putrefactive
+organisms, they are midway in size between the least and largest Bacteria,
+and are, from their form and other conditions, more amenable to research,
+and twelve years ago I resolved, with the highest power lenses and
+considerable practice in their use, to attack the problem of their origin;
+whether as physical products of the not-living, or as the natural progeny
+of parents.
+
+But you will remember that only a minute drop of fluid containing them can
+be examined at one time. This minute drop has to be covered with a minute
+film of glass not more than the 1/200 of an inch thick. The highest lenses
+are employed, working so near as almost to touch the delicate cover.
+Clearly, then, the film of fluid would rapidly evaporate and cause the
+destruction of the object studied. To prevent this an arrangement was
+devised by which the lens and the covered fluid under examination were
+used in an air-tight chamber, the air of which was kept in a saturated
+condition; so that being, like a saturated sponge, unable to take in any
+more, it left the film of fluid unaffected. But to make the work efficient
+I soon found that there must be a second observer. Observation by leaps
+was of no avail. To be accurate it must be unbroken. There must be no gap
+in a chain of demonstration. A thousand mishaps would occur in trying to
+follow a single organism through all the changes of successive hours to
+the end. But, however many failures, it was evident, we must begin on
+another form at the earliest point again, and follow it to the close. I
+saw soon that every other method would have been merely empirical, a mere
+piecemeal of imagination and fact. When one observer's ability to continue
+a long observation was exhausted, there must be another at hand to take up
+the thread and continue it; and thus to the end. I was fortunate indeed at
+this time in securing the ready and enthusiastic aid of Dr. J.J. Drysdale,
+of Liverpool, who practically lived with me for the purpose, and went side
+by side with me to the work. We admitted nothing which we had not both
+seen, and we succeeded each other consecutively, whenever needful, in
+following to the end the complete life-histories of six of these
+remarkable forms.
+
+I will now give you the facts in relation to two which shall be typical.
+We obtained them in enormous abundance in a maceration of fish. I will not
+take them in the order of our researches, but shall find it best to
+examine the largest and the smallest. The appearance of the former is now
+before you. It is divergent from the common type when seen in its perfect
+condition, avoiding the oval form, but it resumes it in metamorphosis. It
+is comparatively huge in its proportions, its average extreme length being
+the 1/1000 of an inch. Its normal form is rigidly adhered to as that of a
+rotifer or a crustacean. Its body-substance is a structureless sarcode.
+Its differentiations are a nucleus-like body, not common to the monads;
+generally a pair of dilating vacuoles, which open and close, like the
+human eyelid, ten to twenty times in every minute; and lastly, the usual
+number of four flagella. That the power of motion in these forms and in
+the Bacteria is dependent upon these flagella I believe there can be no
+reasonable doubt. In the monads, the versatility, rapidity, and power of
+movement are always correlated with the number of these. The one before us
+could sweep across the field with majestic slowness, or dart with
+lightning swiftness and a swallow's grace. It could gyrate in a spiral, or
+spin on its axis in a rectilinear path like a rifled bullet. It could dart
+up or down, and begin, arrest, or change its motion with a grace and power
+which at once astonish and entrance. Fixing on one of these monads then,
+we followed it doggedly by a never-ceasing movement of a "mechanical
+stage," never for an instant losing it through all its wanderings and
+gyrations; We found that in the course of minutes, or of hours, the
+sharpness of its outline slowly vanish, its vacuoles disappeared, and it
+lost its sharp caudal extremity, and was sluggishly amoeboid. This
+condition tensified, the amoeboid action quickened as here depicted, the
+agility of motion ceased, the nucleus body became strongly developed, and
+the whole sarcode was in a state of vivid and glittering action.
+
+If now it be sharply and specially looked for, it will be seen that the
+root of the flagella _splits_, dividing henceforth into two separate
+pairs. At the same moment a motion is set up which pulls the divided pairs
+asunder, making the interval of sarcode to grow constantly greater between
+them. During this time the nuclear body has commenced and continued a
+process of self-division; from this moment the organism grows rapidly
+rounder, the flagella swiftly diverge. A bean-like form is taken; the
+nucleus divides, and a constriction is suddenly developed; this deepens;
+the opposite position of the flagella ensues, the nearly divided forms
+now vigorously pull in opposite directions, the constriction is thus
+deepened and the tail formed. The fiber of sarcode, to which the
+constricted part has by tension been reduced, now snaps, and two organisms
+go free. It will have struck you that the new organism enters upon its
+career with only _two_ flagella, and the normal organism is possessed of
+four. But in a few minutes, three or four at most, the full complement
+were always there. How they were acquired it was the work of months to
+discover, but at last the mystery was solved. The newly-fissioned form
+darted irregularly and rapidly for a brief space, then fixed itself to the
+floor or to a rigid object by the ends of its flagella, and, with its body
+motionless, an intense vibratory action was set up along the entire length
+of these exquisite fibers. Rapidly the ends split, one-half being in each
+fiber set free, and the other remaining fixed, and in 130 seconds each
+entire flagellum was divided into a perfect pair.
+
+Now the amoeboid state is a notable phenomenon throughout the monads as
+precursive of striking change. It appears to subserve the purpose of the
+more facile acquisition and digestion of food at a crisis. And this
+augmented the difficulty of discovering further change; and only
+persistent effort enabled us to discover that with comparative rareness
+there appeared a form in an amoeboid state that was unique. It was a
+condition chiefly confined to the caudal end, the sarcode having became
+diffluent, hyaline, and intensely rapid in the protrusion and retraction
+of its substance, while the nuclear body becomes enormously enlarged.
+These never appear alone; forms in a like condition are diffused
+throughout the fluid, and may swim in this state for hours. Meanwhile, the
+diffluence causes a spreading and flattening of the sarcode and swimming
+gives place to creeping, while the flagella violently lash. In this
+condition two forms meet by apparent accident, the protrusions touch, and
+instant fusion supervenes. In the course of a few seconds there is no
+disconnected sarcode visible, and in five to seven minutes the organism is
+a union of two of the organisms, the swimming being again resumed, the
+flagella acting in apparent concert. This may continue for a short time,
+when movement begins to flag and then ceases. Meanwhile, the bodies close
+together, and the eyenots or vacuoles melt together, the two nuclei become
+one and disappear, and in eighteen hours the entire body of "either has
+melted into other," and a motionless, and for a time irregular, sac is
+left. This now becomes smooth, spherical, and tight, being fixed and
+motionless. This is a typical process; but the mingled weariness and
+pleasure realized in following such a form without a break through all the
+varied changes into this condition is not easily expressed.
+
+But now the utmost power of lenses, the most delicate adjustment of light,
+and the keenest powers of eyesight and attention must do the rest. Before
+the end of six hours the delicate glossy sac opens gently at one place,
+then there streams out a glairy fluid densely packed with semi-opaque
+granules, just fairly visible when their area was increased six millions
+of times, and this continued until the whole sac was empty and its entire
+contents diffused. To follow with our utmost powers these exquisite specks
+was an unspeakable pleasure, a group seen to roll from the sac, when
+nearly empty, were fixed and never left. They soon palpably changed by
+apparent swelling or growth, but were perfectly inactive; but at the end
+of three hours a beaked appearance was presented. Rapid growth set in, and
+at the end of another hour, how has entirely baffled us, they acquired
+flagella and swam freely; in thirty-five minutes more they possessed a
+nucleus and rapidly developed, until at the end of nine hours after
+emission a sporule was followed to the parent condition and left in the
+act of fission. In this way, with what difficulties I need not weary you,
+a complete life-cycle was made out.
+
+And now I will invite your attention to the developmental history of the
+_most minute_ of the six forms we studied. In form it is a long oval, it
+is without visible structure or differentiation within, and is possessed
+of only a single flagellum. Its utmost length is the 1/5000 of an inch.
+Its motion is continuous in a straight line, and not intensely rapid, nor
+greatly varied, being wholly wanting in curves and dartings. The
+copiousness of its increase was, even to our accustomed eyes, remarkable
+in the extreme, but the reason was discovered with comparative ease. Its
+fission was not a division into two, but into many. The first indication
+of its approach in following this delicate form was the assumption rapidly
+of a rounder shape. Then followed an amoeboid and uncertain form, with
+an increased intensity of action which lasted a few moments, when
+lassitude supervened, then perfect stillness of the body, which is now
+globular in form, while the flagellum feebly lashed, and then fell upon
+and fused with the substance of the sarcode. And the result is a solid,
+flattened, homogeneous ball of living jelly.
+
+To properly study this in its further changes, a power of from three to
+four thousand diameters must be used, and with this I know of few things
+in the whole range of minute beauty more beautiful than the effect of what
+is seen. In the perfectly motionless flattened sphere, without the shimmer
+of premonition and with inconceivable suddenness, a white cross smites
+itself, as it were, through the sarcode. Then another with equal
+suddenness at right angles, and while with admiration and amazement one
+for the first time is realizing the shining radii, an invisible energy
+seizes the tiny speck, and fixing its center, twists its entire
+circumference, and endows it with a turbined aspect. From that moment
+intense interior activity became manifest. Now the sarcode was, as it
+were, kneading its own substance, and again an inner whirling motion was
+visible, reminding one of the rush of water round the interior of a hollow
+sphere on its way to a jet or fountain. Deep fissures or indentations
+showed themselves all over the sphere; and then at the end of ten or more
+minutes all interior action ceased, and the sphere had segmented into a
+coiled mass. There was no trace of an investing membrane; the constituent
+parts were related to each other simply as the two separating parts of an
+ordinary fission; and they now commenced a quick, writhing motion like a
+knot of eels, and then, in the course of from seven to thirty minutes,
+separated, and fully endowed with flagella swam freely away, minute but
+perfect forms, which by the rapid absorption of pabulum attained speedily
+to the parent size.
+
+It is characteristic of this group of organic forms that multiplication
+by self-division is the common and continuous method of increase. The
+other and essential method was comparatively rare and always obscure. In
+this instance, on the first occasion the continuous observation of the
+same "field" for five days failed to disclose to us any other method of
+increase but this multiple-fission, and it was only the intense
+suggestiveness of past experience that kept us still alert and prevented
+us from inferring that it was the _only_ method. But eventually we
+perceived that while this was the prevailing phenomenon, there were
+scattered among the other forms of the same monad _larger_ than the rest,
+and with a singular granular aspect toward the flagellate end. It may be
+easily contrasted with the normal or ordinary form. Now by doggedly
+following one of these through all its wanderings a wholly new phase in
+the morphology of the creature was revealed. This roughened or granular
+form seized upon and fastened itself to a form in the ordinary condition.
+The two swam freely together, both flagella being in action, but it was
+shortly palpable that the larger one was absorbing the lesser. The
+flagellum of the smaller one at length moved slower, then sluggishly, then
+fell upon the sarcode, which rapidly diminished, while the bigger form
+expanded and became vividly active until the two bodies had actually fused
+into one. After this its activity diminished, in a few minutes the body
+became quite still, leaving only a feeble motion in the flagellum, which
+soon fell upon the body-substance and was lost. All that was left now was
+a still spheroidal glossy speck, tinted with a brownish yellow. A
+peculiarity of this monad is the extreme uncertainty of the length of time
+which may elapse before even the most delicate change in this sac is
+visible. Its absolute stillness may continue for ten or more hours. During
+this time it is absolutely inert, but at last the sac--for such it
+is--opens gently, and there is poured out a brownish glairy fluid. At
+first the stream is small, but at length its flow enlarges the rift in the
+cyst, and the cloudy volume of its contents rolls out, and the hyaline
+film that inclosed it is all that is left.
+
+The nature of the outflow was like that produced by the pouring of strong
+spirit into water. But no power that we could employ was capable of
+detecting a _granule_ in it. To our most delicate manipulation of light,
+our finest optical appliances, and our most riveted attention, it was a
+homogeneous fluid and nothing more. This for a while baffled and disturbed
+us. It lured us off the scent. We inferred that it might possibly be a
+fertilizing fluid, and that we must look in other directions for the
+issue. But this was fruitless, and we were driven again to the old point,
+and having once more obtained the emitted fluid, determined to fix a lens
+magnifying 5,000 diameters upon a clear space over which the fluid had
+rolled, and near to the exhausted sac, and ply our old trade of _watching_
+with unbroken observation.
+
+The result was a reward indeed. At first the space was clear and white,
+but in the course of a hundred minutes there came suddenly into view the
+minutest conceivable specks. I can only compare the coming of these to the
+growth of the stars in a starless space upon the eye of an intense watcher
+in a summer twilight. You knew but a few minutes since a star was not
+visible there, and now there is no mistaking its pale beauty. It was so
+with these inexpressibly minute sporules; they were not there a short time
+since, but they grew large enough for our optical aids to reveal them, and
+there they were. Such a field after one hour's watching I present to you.
+And here I would remark that these delicate specks were unlike any which
+we saw emerge directly from the sac as granules. In that condition they
+were always semi-opaque, but here they were transparent, and a brown
+yellow, the condition always sequent upon a certain measure of growth.
+
+To follow these without the loss of an instant's vision was pleasure of
+the highest kind. In an hour and ten minutes from their first discovery
+they had grown to oval points. In one hour more the specks had become
+beaked and long. And this pointed end was universally the end from which
+the flagellum emerged. With the flagellum comes motion, and with that
+abundant pabulum, and therefore rapid growth. But when motion is attained
+we are compelled to abandon the mass and follow one in all its impetuous
+travels in its little world; and by doing so we are enabled to follow the
+developed speck into the parent condition and size, and not to leave it
+until it had, like its predecessors, entered on and completed its
+wonderful self-division by fission.
+
+It becomes then clearly manifest that these organisms, lowly and little as
+they are, arise in fertilized parental products. There is no more caprice
+in their mode of origin than in that of a crustacean or a bird. Their
+minuteness, enormous abundance, and universal distribution is the
+explanation of their rapid and practically ubiquitous appearance in a
+germinating and adult condition. The presence of putrefiable or putrescent
+matter determines at once the germination of the always-present spore. But
+a new question arises. These spores are definite products. In the face of
+some experimental facts one was tempted to inquire: Have these spores any
+capacity to resist heat greater than the adults? It was not easy to
+determine this question. But we at length were enabled to isolate the
+germs of seven separate forms, and by means of delicate apparatus, and
+some twelve months of research, to place each spore sac in an apparatus so
+constructed that it could be raised to successive temperatures, and
+without any change of conditions examined on the stage of the microscope.
+
+In this way we reached successive temperatures higher and higher until the
+death point--the point beyond which no subsequent germination ever
+occurred--was reached in regard to _each_ organism. The result was
+striking. The normal death point for the adult was 140° F. One of the
+monads emitted from its sac minute mobile specks--evidently living
+bodies--which rapidly grew. These we always destroyed at a temperature of
+180° F. Three of the sacs emitted spores that germinated at every
+temperature under 250° F. Two more only had their power of germination
+destroyed at 260° F. And one, the least of all the monad forms, in a heat
+partially fluid and partially dry, at all points up to 300° F. But if
+wholly in fluid it was destroyed at the point of 290° F. The average being
+that the power of heat resistance in the spore was to that of the adult
+as 11 to 6. From this it is clear that we dare not infer spontaneous
+generation after heat until we know the life-history of the organism.
+
+In proof of this I close with a practical case. A trenchant and resolute
+advocate of the origin of living forms _de novo_ has published what he
+considers a crucial illustration in support of his case. He took a strong
+infusion of common cress, placed it in a flask, boiled it, and, while
+boiling, hermetically sealed it. He then heated it up in a digester to
+270° F. It was kept for nine weeks and then opened, and, in his own
+language, on microscopical examination of the earliest drop "there
+appeared more than a dozen very active monads." He has fortunately
+measured and roughly drawn these. A facsimile of his drawing is here. He
+says that they were possessed of a rapidly moving lash, and that there
+were other forms without tails, which he assumed were developmental stages
+of the form. This is nothing less than the monad whose life-history I gave
+you last. My drawings, magnified 2,500 diams., of the active organism and
+the developing sac are here.
+
+Now this experimenter says that he took these monads and heated them to a
+temperature of about 140° F., and they were all absolutely killed. This is
+accurately our experience. But he says these monads arose in a closed
+flask, the fluid of which had been heated up to 270° F. Therefore, since
+they are killed at 140° F., and arose in a fluid after being heated to
+270° F., they must have arisen _de novo!_ But the truth is that this is
+the monad whose spore only loses its power to germinate at a temperature
+(in fluid) of 290°, that is to say, 20° F. higher than the heat to which,
+in this experiment, they had been subjected. And therefore the facts
+compel the deduction that these monads in the cress arose, not by a change
+of dead matter into living, but that they germinated naturally from the
+parental spore which the heat employed had been incompetent to injure.
+Then we conclude with a definite issue, viz., by experiment it is
+established that living forms do not now arise in dead matter. And by
+study of the forms themselves it is proved that, like all the more complex
+forms above them, they arise in parental products. The law is as ever,
+only that which is living can give origin to that which lives.
+
+       *       *       *       *       *
+
+A catalogue, containing brief notices of many important scientific papers
+heretofore published in the SUPPLEMENT, may be had gratis at this office.
+
+
+       *       *       *       *       *
+
+
+THE SCIENTIFIC AMERICAN SUPPLEMENT.
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+PUBLISHED WEEKLY.
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+Sent by mail, postage prepaid, to subscribers in any part of the United
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+1876, can be had. Price, 10 cents each.
+
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+MUNN & CO., PUBLISHERS,
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+361 BROADWAY, NEW YORK, N.Y.
+
+       *       *       *       *       *
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+PATENTS.
+
+
+In connection with the SCIENTIFIC AMERICAN, Messrs. MUNN & Co. are
+Solicitors of American and Foreign Patents, have had 40 years' experience,
+and now have the largest establishment in the world. Patents are obtained
+on the best terms.
+
+A special notice is made in the SCIENTIFIC AMERICAN of all inventions
+patented through this Agency, with the name and residence of the Patentee.
+By the immense circulation thus given, public attention is directed to the
+merits of the new patent, and sales or introduction often easily effected.
+
+Any person who has made a new discovery or invention can ascertain, free
+of charge, whether a patent can probably be obtained, by writing to MUNN &
+Co.
+
+We also send free our Hand Book about the Patent Laws, Patents, Caveats.
+Trade Marks, their costs, and how procured. Address
+
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+
+Branch Office, cor. F and 7th Sts., Washington, D.C.
+
+
+
+
+
+End of the Project Gutenberg EBook of Scientific American Supplement, Vol.
+XIX, No. 470, Jan. 3, 1885, by Various
+
+*** END OF THE PROJECT GUTENBERG EBOOK 14041 ***