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diff --git a/14041-0.txt b/14041-0.txt new file mode 100644 index 0000000..d780d6a --- /dev/null +++ b/14041-0.txt @@ -0,0 +1,3599 @@ +*** 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. 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