The Project Gutenberg EBook of Scientific American Supplement, No. 365, December 30, 1882, by Various This eBook is for the use of anyone anywhere at no cost and with almost no restrictions whatsoever. You may copy it, give it away or re-use it under the terms of the Project Gutenberg License included with this eBook or online at www.gutenberg.org Title: Scientific American Supplement, No. 365, December 30, 1882 Author: Various Release Date: July 6, 2006 [EBook #18763] Language: English Character set encoding: ISO-8859-1 *** START OF THIS PROJECT GUTENBERG EBOOK SCIENTIFIC AMERICAN *** Produced by David King, Juliet Sutherland and the Online Distributed Proofreading Team at http://www.pgdp.net Issue Title SCIENTIFIC AMERICAN SUPPLEMENT NO. 365 NEW YORK, DECEMBER 30, 1882. Scientific American Supplement. Vol. XIV., No. 365. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. TABLE OF CONTENTS. PAGE. I. ENGINEERING AND MECHANICS.—Louis Favre, Constructor of the St. Gothard Tunnel.—2 figures.—Portrait and monument at Turin to commemorate the tunneling of the Alps 5817 The New Harbor of Vera Cruz.—New artificial harbor for Vera Cruz.—Capt. Eads's plan.—1 figure.—Plan of harbor and improvement 5818 Cost of Power to Make Flour 5818 Driving gear Mechanism for Lift Hammers.—2 figures 5819 De Junker and Ruh's Machine for Cutting Annular Wheels.—3 figures 5819 Recent Hydraulic Experiments.—Results of experiments on the flow of water in the Ganges Canal 5819 The Germ: Shall It be Retained in Flour? By Arthur Atkins 5820 Wheat Tests 5820 II. TECHNOLOGY AND CHEMISTRY.—Apparatus for Manufacturing Gaseous or Aerated Beverages.—11 figures.—Bicarbonate of soda apparatus. Generator. Washer. —Suction pump.—Saturator.—Apparatus for using carbonate of lime.—Apparatus completely mechanical in operation 5815 Detection and Estimation of Fusel Oil 5816 On Silicon.—Curious formation of silicide of platinum 5816 Stannous Nitrates.—The formation of explosive compounds in machines by the corrosion of bronze and tin solder 5816 Metallic Thorium. By L.F. Nilson 5816 Friedrich Wöhler.—Obituary notice of the great German chemist 5816 Apparatus for Printing by the Blue Process. By Channing Whitaker.—3 figures 5820 III. ELECTRICITY, LIGHT, HEAT, ETC.—Spectrum Gratings 5822 A New Pocket Opera Glass.—4 figures 5822 Atoms, Molecules, and Ether Waves. By John Tyndall. Action of heat and light on molecules.—Heat as an agent in exploring molecular conditions.—The results of a recent incursion into the extra-sensible world of atoms and molecules 5823 Apparatus for Measuring Electricity at the Upper School of Telegraphy. By E. Mercadier.—5 figures. Constant vibrator.—The Electrical tuning fork. Arrangement for testing electric piles.—Very rapid electric tuning fork.—A vibrating micrometer 5824 IV. NATURAL HISTORY.—Our Origin as a Species. By Richard Owen.—The Neanderthal skull.—Differential characters between the lowest _Homo_ and the highest _Simia_ 5825 The Aba or Odika. By Dr. W.H. Bacheler.—A remarkable tree of West Africa 5826 California Cedars 5826 Ancient Greek Painting. (Transcriber's Note: Added to Table of Contents.) 5822 APPARATUS FOR MANUFACTURING GASEOUS OR AERATED BEVERAGES. The apparatus employed at present for making gaseous beverages are divided into two classes— intermittent apparatus based on chemical compression, and continuous ones based on mechanical compression. The first are simple in appearance and occupy small space, but their use is attended with too great inconveniences and losses to allow them to be employed in cases where the manufacture is of any extent, so the continuous apparatus are more and more preferred by those engaged in the industry. Continuous apparatus, however, other than those that we now propose to occupy ourselves with, are not without some defects, for the gas is produced in them intermittingly and at intervals, and more rapidly than it is used, thus necessitating the use of a gasometer, numerous and large washers, complicated piping, and, besides, of an acid cock. To get rid of such drawbacks, it became necessary to seek a means of rendering the production of the gas continuous, and of regulating it automatically without the aid of the operator. Mr. Mondollot has obtained such a result through a happy modification of the primitive system of the English engineer Bramah. He preserves the suction and force pump but, while applying it to the same uses, he likewise employs it, by the aid of a special arrangement, so as to distribute the sulphuric acid automatically over the chalk in the generator, and to thus obtain a regular and continuous disengagement of carbonic acid gas. The dangers and difficulties in the maneuver of an acid cock are obviated, the gasometer and its cumbersome accessories are dispensed with, and the purification is more certain, owing to the regularity with which the gas traverses the washers. APPARATUS FOR MANUFACTURING GASEOUS BEVERAGES. In the accompanying plate we have figured three types of these apparatus. The first that we shall describe is arranged for the use of bicarbonate of soda. This apparatus consists (1) of a generator, C D, (2) of a double washer G G, (3) of a suction pump, P, and (4) of a saturator, S (See Figs 1 to 9). The Generator.—This consists of a cylindrical leaden receptacle, D, on the bottom of which rests a leaden bell containing apertures, c, at its base. A partition, c, into which is screwed a leaden tube, C, containing apertures divides the interior of the bell into two compartments. The upper of these latter is surmounted by a mouth, B, closed by a clamp, and through which the bicarbonate of soda is introduced. A definite quantity of water and sulphuric acid having been poured into the receptacle, D, a level tends to take place between the latter and the bell, C, the liquid passing through the apertures. But the acidulated water, coming in contact with the soda, sets free carbonic acid gas, which, having no exit, forces the water back and stops the production of gas until the apparatus is set in motion. At this moment, the suction of the pump causes a new inflow of acidulated water upon the soda, from whence another disengagement of gas, and then a momentary forcing of the water, whose level thus alternately rises and falls and causes a continuous production of gas proportionate with the suction of the pump. The consumption of soda and acid is about 2 kilogrammes each for charging 100 siphons or 150 bottles. The bicarbonate is known to be used up when the liquid in the generator is seen to descend to the bottom of the water level, n, fixed to the vessel, D. The Washer (Figs 1 and 4)—The gas, on leaving the generator, enters the washer through a bent copper pipe, R. The washer is formed of two ovoid glass flasks G G, mounted on a bronze piece, L, to which they are fixed by screw rings, l, of the same metal. The two flasks, G G, communicate with each other only through the tinned-copper tube q, which is held in the mounting q, of the same metal. This latter is screwed into the piece, L, and contains numerous apertures, through which the gas coming in from the pipe, R, passes to reach the upper flask, G. The gas is washed by bubbling up through water that has been introduced through the cock, R. After it has traversed both flasks, it escapes through the copper pipe, p, into which it is sucked by the pump, P. The Pump (Figs 1, 5 and 6)—This consists of a cylindrical chamber, P, of bronze, bolted to a bracket on the frame, and cast in a piece, with the suction valve chamber, P, in which the valve, p, plays. It is surmounted by the distributing valve chamber P2. This latter is held by means of two nuts screwed on to the extremity of the rods, p3, connected with the shell, E, of the distributing-cock, E. In the shell, E, terminates, on one side, the pipe, p, through which enters the gas from the washer, and, on the other, the pipe i, that communicates with a feed-reservoir not shown in the cuts. The cock E, permits of the simultaneous regulation of the entrance of the gas and water. Its position is shown by an index e, passing over a graduated dial, e. From the distributing valve chamber, P2 the pipe, s, leads the mixture of water and gas under pressure into The Saturator, S (Figs 1, 7 and 9)—This consists of a large copper vessel, s, affixed to the top of the frame through the intermedium of a bronze collar h, and a self closing bottom H. This latter is provided with two pipes, one of which, s, leads the mixture of water and carbonic acid forced by the pump, and the other, b, communicates with the siphons or bottles to be filled. The pipe, b, is not affixed directly to the bottom, but is connected therewith through the intermedium of a cock, r. The object of the broken form of this pipe is to cause the pressure to act according to the axis of the screw, r, which is maneuvered by the key, r2. The water under pressure, having been forced into the vessel, S, is submitted therein to an agitation that allows it to dissolve a larger quantity of gas. Such agitation is produced by two pairs of paddles, J J, mounted at the extremity of an axle actuated by the wheel, A, through the intermedium of gearings, g and g. The course of the operation in the saturator may be followed by an inspection of the water level, n, seen at the front and side in Figs. 2 and 3. This apparatus, in which the pressure reaches 4 to 6 atmospheres in the manufacture of Seltzer water or gaseous lemonade in bottles, and from 10 to 12 atmospheres in that of Seltzer water in siphons, is provided also with a pressure gauge, m, and a safety valve, both screwed, as is also the tube, n2, into a sphere, S, on the top of the saturator. Apparatus for Using Carbonate of Lime (Figs 2, 3, and 10)—When chalk is acted upon by sulphuric acid, there is formed an insoluble sulphate which, by covering the chalk, prevents the action of the acid from continuing if care be not taken to constantly agitate the materials. This has led to a change in the arrangement of the generator in the apparatus designed for the use of chalk. It consists in this case of a leaden vessel, D, having a hemispherical bottom set into a cylindrical cast iron base, K, and of an agitator similar to that shown in Fig. 11, for keeping the chalk in suspension in the water. These latter materials are introduced through the mouth, B (Fig. 3). Then a special receptacle, C, of lead, shown in detail in Fig. 10, and the cock, c, of which is kept closed, is filled with sulphuric acid. The acid is not introduced directly into the vessel, C, but is poured into the cylinder, C, whose sides contain numerous apertures which prevent foreign materials from passing into the siphon tube c, and obstructing it. To put the apparatus in operation, the acid cock, c, is opened and the wheel, A, is turned, thus setting in motion both the pump piston, P, and the agitator, within S and D. Then the play of the pump produces a suction in the washers and from thence in the generator and causes the acid in the vessel, C, to flow into the generator through the leaden siphon tubes, c. Coming in contact with the chalk in suspension, the acid produces a disengagement of gas which soon establishes sufficient pressure to stop the flow of the acid and drive it back into the siphon tube. The play of the pump continuing, a new suction takes place and consequently a momentary flow of acid and a new disengagement of gas. Thus the production of the latter is continuous, and is regulated by the very action of the pump, without the operator having to maneuver an acid-cock. The latter he only has to open when he sets the apparatus in operation, and to close it when he stops it. The arrangement of the washer is the same as in the preceding apparatus, save that a larger cylindrical copper reservoir, G', is substituted for the lower flask. The pump and saturator offer nothing peculiar. A bent tube, u, which communicates with the generator, D, on one side, and with a cylindrical tube, V, ending in a glass vessel on the other, serves as a safety-valve for both the generator and the acid vessel. The consumption of chalk is about 2.5 kilogrammes, and the same of acid, for charging 100 siphons or 150 bottles. The apparatus shown in the figure is capable of charging 600 siphons or 900 bottles per day. An Apparatus Completely Mechanical in Operation (Fig. 11).—This apparatus consists of two very distinct parts. The saturator, pump, and driving shaft are supported by a hollow base, in whose interior are placed a copper washer and the water-inlet controlled by a float-cock. This part of the apparatus is not shown in the plate. The generator, partially shown in Fig. 11, is placed on a base of its own, and is connected by a pipe with the rest of the apparatus. It consists of two similar generators, D, made of copper lined with lead, and working alternately, so as to avoid all stoppages in the manufacture when the materials are being renewed. The pipe, d, connecting the two parts of the apparatus forks so as to lead the gas from one or the other of the generators, whence it passes into the copper washer within the base, then into the glass indicating washer, and then to the pump which forces it into the saturator. Each of the generators communicates by special pipes, a, with a single safety vessel, V, that operates the same as in the preceding apparatus. The agitator, Q, is of bronze, and is curved as shown in Fig. 11. The production of this type of apparatus is dependent upon the number of siphons that can be filled by a siphon filler working without interruption.—Machines, Outils et Appareils. DETECTION AND ESTIMATION OF FUSEL OIL. Until quite recently we have had no accurate method for the determination of fusel oil in alcohol or brandy. In 1837 Meurer suggested a solution of one part of silver nitrate in nine parts of water as a reagent for its detection, stating that when added to alcohol containing fusel oil, a reddish brown color is produced, and in case large quantities are present, a dark brown precipitate is formed. It was soon found, however, that other substances than amyl alcohol produce brown colored solutions with silver nitrate; and Bouvier1 observed that on adding potassium iodide to alcohol containing fusel oil, the solution is colored yellow, from the decomposition of the iodide. Subsequently Böttger2 proved that potassium iodide is not decomposed by pure amyl alcohol, and that the decomposition is due to the presence of acids contained in fusel oil. More accurate results are obtained by using a very dilute solution of potassium permanganate, which is decomposed by amyl alcohol much more rapidly than by ethyl alcohol. Depré3 determines fusel oil by oxidizing a definite quantity of the alcohol in a closed vessel with potassium bichromate and sulphuric acid. after removal of excess of the oxidizing reagents, the organic acids are distilled, and, by repeated fractional distillation, the acetic acid is separated as completely as possible. The remaining acids are saturated with barium hydroxide, and the salts analyzed; a difference between the percentage of barium found and that of barium in barium acetate proves the presence of fusel oil, and the amount of difference gives some idea of its quantity. Betelli4 dilutes 5 c.c. of the alcohol to be tested with 6 to 7 volumes of water, and adds 15 to 20 drops of chloroform and shakes thoroughly. If fusel oil is present, its odor may be detected by evaporating the chloroform; or, by treatment with sulphuric acid and sodium acetate, the ether is obtained, which can be readily recognized. Jorissen5 tests for fusel oil by adding 10 drops of colorless aniline and 2 to 3 drops of hydrochloric acid to 10 c.c. of the alcohol. In the presence of fusel oil a red color is produced within a short time, which can be detected when not more than 0.1 per cent. is present. But Foerster6 objects to this method because he finds the color to be due to the presence of furfurol, and that pure amyl alcohol gives no color with aniline and hydrochloric acid. Hager7 detects fusel oil as follows: If the spirit contains more than 60 per cent. of alcohol, it is diluted with an equal volume of water and some glycerine added, pieces of filter paper are then saturated with the liquid and exposed to the After the evaporation of the alcohol, the odor of the fusel oil can be readily detected. For the quantitative determination he distills 100 c.c. of the alcohol in a flask of 150 to 200 c.c. capacity connected with a condenser, and so arranged that the apparatus does not extend more than 20 cm. above the water bath. This arrangement prevents the fusel oil from passing over. If the alcohol is stronger than 70 per cent., and the height of the distillation apparatus is not more than 17 cm., the residue in the flask may be weighed as fusel oil. With a weaker alcohol, or an apparatus which projects further out of the water bath, the residual fusel oil is mixed with water. It can, however, be separated by adding strong alcohol and redistilling, or by treating with ether, which dissolves the amyl alcohol, and distilling, the temperature being raised finally to 60°. Marquardt,8 like Betelli, extracts the fusel oil from alcohol by means of chloroform, and by oxidation converts it into valeric acid. From the quantity of barium valerate found he calculates the amount of amyl alcohol present in the original solution; 150 c.c. of the spirit, which has been diluted so as to contain 12 to 15 per cent. of alcohol, are shaken up thoroughly with 50 c.c. of chloroform, the aqueous layer drawn off, and shaken with a fresh portion of chloroform. This treatment is repeated several times. The extracts are then united, and washed repeatedly with water. The chloroform, which is now free from alcohol and contains all the fusel oil, is treated with a solution of 5 grammes of potassium bichromate in 30 grammes of water and 2 grammes of sulphuric acid, and then heated in a closed flask for six hours on a water bath at 85°. The contents of the flask are then distilled, the distillate saturated with barium carbonate, and the chloroform distilled; the residue is evaporated to a small volume, the excess of barium carbonate filtered off, and the filtrate evaporated to dryness and weighed. The residue is dissolved in water, a few drops of nitric acid added, and the solution divided into two portions. In the first portion the barium is determined; in the second the barium chloride. The total per cent. of barium minus that of barium chloride gives the amount present as barium valerate, from which is calculated the per cent. of amyl alcohol. By this process the author has determined one part of fusel oil in ten thousand of alcohol. To detect very minute quantities of fusel oil, the chloroform extracts are treated with several drops of sulphuric acid and enough potassium permanganate to keep the solution red for twenty-four hours. If allowed to stand in a test tube, the odor of valeric aldehyde will first be noticed, then that of amyl valerate, and lastly that of valeric acid.—Amer. Chem. Journal. [1] Zeitschrift f. Anal. Chem. xi., 343. [2] Dingler's Polytech. Jour., ccxii., 516. [3] Pharm. J. Trans. [3] vi., 867. [4] Berichte d. Deutschen Chem. Gesellsch., viii., 72. [5] Pharm. Centralhalle, xxii., 3. [6] Berichte d. Deutsch. Chem. Gesellsch., xv., 230. [7] Pharm. Centralhalle, xxii., 236. [8] Berichte d. Deutsch. Chem. Gesellsch., xv., 1,370 and 1,663. ON SILICON. It is known that platinum heated in a forge fire, in contact with carbon, becomes fusible. Boussingault has shown that this is due to the formation of a silicide of platinum by means of the reduction of the silica of the carbon by the metal. MM. P. Schützenberger and A. Colson have produced the same phenomenon by heating to white heat a slip of platinum in the center of a thick layer of lampblack free from silica. The increase in weight of the metal and the augmentation of its fusibility were found to be due, in this case also, to a combination with silicon. As the silicon could not come directly from the carbon which surrounded the platinum, MM. Schützenberger and Colson have endeavored to discover under what form it could pass from the walls of the crucible through a layer of lampblack several centimeters in thickness, in spite of a volatility amounting to almost nothing under the conditions of the experiment. They describe the following experiments as serving to throw some light upon the question: 1. A thin slip of platinum rolled in a spiral is placed in a small crucible of retort carbon closed by a turned cover of the same material. This is placed in a second larger crucible of refractory clay, and the intervening space filled with lampblack tightly packed. The whole is then heated to white heat for an hour and a half in a good wind furnace. After cooling, the platinum is generally found to have been fused into a button, with a marked increase in weight due to taking up silicon, which has penetrated in the form of vapor through the walls of the interior crucible. 2. If, in the preceding experiment, the lampblack be replaced by a mixture of lampblack and rutile in fine powder, the slip of platinum remains absolutely intact, and does not change in weight. Thus the titaniferous packing recommended by Sainte-Claire Deville for preventing the access of nitrogen in experiments at high temperatures also prevents the passage of silicon. A mixture of carbon and finely divided iron is, on the contrary, ineffectual. These facts seem to indicate that nitrogen plays a part in the transportation of the silicon, as this is only prevented by the same means made use of in order to prevent the passage of nitrogen. 3. The volatility of free silicon at a high temperature is too slight to account for the alteration of the platinum at a distance. This can be shown by placing several decigrammes of crystallized silicon on the bottom of a small crucible of retort carbon, covering the silicon with a small flat disk of retort carbon upon which is placed the slip of platinum. The crucible, closed by its turned cover, is then enveloped in a titaniferous packing and kept at a brilliant white heat for an hour and a half. The metal is found to have only very slightly increased in weight, and its properties remain unaltered. This experiment was repeated several times with the same result. If, however, the crystallized silicon be replaced by powdered calcined silica, the platinum, placed upon the carbon disk, fuses and increases in weight, while the silica loses weight. The theory of these curious phenomena is very difficult to establish on account of the high temperatures which are necessary for their manifestation, but it may be concluded, at present, that nitrogen and probably oxygen also play some part in the transportation of the silicon across the intervening space, and that the carbosilicious compounds recently described by MM. Schützenberger and Colson also take part in the phenomenon.—Comptes Rendus, xciv., 1,710.—Amer. Chem. Journal. STANNOUS NITRATES. At the Royal Powder Works at Spandau, Prussia, frequent ignition of the powder at a certain stage of the process led to an examination of the machinery, when it was found that where, at certain parts, bronze pieces which were soldered were in constant contact with the moist powder, the solder was much corroded and in part entirely destroyed, and that in the joints had collected a substance which, on being scraped out with a chisel, exploded with emission of sparks. It was suspected that the formation of this explosive material was in some way connected with the corrosion of the solder, and the subject was referred for investigation to Rudolph Weber, of the School of Technology, at Berlin. The main results of his investigation are here given. The explosive properties of the substance indicated a probable nitro-compound of one of the solder metals (tin and lead), and as the lead salts are more stable and better understood than those of tin, it was resolved to investigate the latter, in hope of obtaining a similar explosive compound. Experiments on the action of moist potassium nitrate on pure tin led to no result, as no explosive body was formed. Stannous nitrate, Sn(NO3)2, formed by the action of dilute nitric acid on tin, has long been known, but only in solution, as it is decomposed on evaporating. By adding freshly precipitated moist brown stannous oxide to cool nitric acid of sp. gr. 1.20, as long as solution occurred, and then cooling the solution to -20°, Weber obtained an abundance of crystals of the composition Sn(NO3)2 + 20H2O. They resemble crystals of potassium chlorate. They cannot be kept, as they liquefy at ordinary temperatures. An insoluble basic salt was obtained by digesting an excess of moist stannous oxide in solution of stannous nitrate, or by adding to a solution of stannous nitrate by degrees, with constant stirring, a quantity of sodium carbonate solution insufficient for complete precipitation. Thus obtained, the basic salt, which has the composition Sn2N2O7, is a snow-white crystalline powder, which is partially decomposed by water, and slowly oxidized by long exposure to the air, or by heating to 100°. By rapid heating to a higher temperature, as well as by percussion and friction, it explodes violently, giving off a shower of sparks. This compound is also formed when a fine spray of nitric acid (sp. gr. 1.20) is thrown upon a surface of tin or solder. It is also formed when tin or solder is exposed to the action of a solution of copper nitrate, and thus formed presents the properties already described. In this, then, we have a probable cause of the explosions occurring in the powder works; but the explanation of the formation of the substance is wanting, as potassium nitrate was shown not to give an explosive substance with tin. A thin layer of a mixture of sulphur and potassium nitrate was placed between sheets of tin and copper foil, and allowed to stand, being kept constantly moist. After a time the copper was found to have become coated with sulphide, while the tin was largely converted into the explosive basic nitrate. The conditions are obviously the same as those found in the powder machinery, where bronze and tin solder are constantly in contact with moist gunpowder. The chemical action is probably this: the sulphur of the powder forms, with the copper of the bronze, copper sulphide; this is oxidized to sulphate, which reacts with the niter of the powder, forming potassium sulphate and copper nitrate; the latter, as shown above, then forms with the tin of the solder the explosive basic nitrate, which, being insoluble, gradually collects in the joints, and finally leads to an explosion.—Journal für Praktische Chemie. METALLIC THORIUM. BY L.F. NILSON. The density of thorium as obtained by reducing the anhydrous chloride by means of sodium was found by Chydenius, 7.657 to 7.795. The author has obtained metallic thorium by heating sodium with the double anhydrous thorium potassium chloride, in presence of sodium chloride in an iron crucible. After treating the residue with water there remains a grayish, heavy, sparkling powder, which under the microscope appears to consist of very small crystals. Metallic thorium is brittle and almost infusible; the powder takes a metallic luster under pressure, is permanent in the air at temperatures up to 120°, takes fire below a red heat either in air or oxygen, and burns with a dazzling luster, leaving a residue of perfectly white thoria. If heated with chlorine, bromine, iodine, and sulphur, it combines with them with ignition. It is not attacked by water, cold or hot. Dilute sulphuric acid occasions the disengagement of hydrogen, especially if heated, but the metal is acted on very slowly. Concentrated sulphuric acid with the aid of heat attacks the metal very slightly, evolving sulphurous anhydride. Nitric acid, strong or weak, has no sensible action. Fuming hydrochloric acid and aqua regia attack thorium readily, but the alkalies are without action. The metal examined by the author behaves with the reagents in question the same as did the specimens obtained by Berzelius. The mean specific gravity of pure thorium is about 11. Hence it would seem that the metal obtained by Chydenius must have contained much foreign matter. The specific gravity of pure thoria is 10.2207 to 10.2198. The equivalent and the density being known, we may calculate the atomic volume. If we admit that the metal is equivalent to 4 atoms of hydrogen, we obtain the value 21.1. This number coincides with the atomic volumes of zirconium (21.7), cerium (21.1), lanthanum (22.6), and didymium (21.5). This analogy is certainly not due to chance; it rather confirms the opinion which I have put forward in connection with my researches on the selenites, on certain chloro- platinates and chloro-platinites, etc., that the elements of the rare earths form a series of quadrivalent metals. [AMERICAN CHEMICAL JOURNAL.] FRIEDRICH WÖHLER. No one but a chemist can appreciate the full significance of the brief message which came to us a month ago without warning—"Wöhler is dead!" What need be added to it? No chemist was better known or more honored than Wöhler, and none ever deserved distinction and honor more than he. His life was made up of a series of brilliant successes, which not only compelled the admiration of the world at large, but directed the thoughts of his fellow workers, and led to results of the highest importance to science. It is impossible in a few words to give a correct account of the work of Wöhler, and to show in what way his life and work have been of such great value to chemistry. Could he himself direct the preparation of this notice, the writer knows that his advice would be, "Keep to the facts." So far as any one phrase can characterize the teachings of Wöhler, that one does it; and though enthusiasm prompts to eulogy, let us rather recall the plain facts of his life, and let them, in the main, speak for themselves.1 He was born in the year 1800 at Eschersheim, a village near Frankfort-on-the-Main. From his earliest years the study of nature appears to have been attractive to him. He took great delight in collecting minerals and in performing chemical and physical experiments. While still a boy, he associated with a Dr. Buch, of Frankfort, and was aided by this gentleman, who did what he could to encourage in the young student his inclination toward the natural sciences. The first paper which bears the name of Wöhler dates from this period, and is upon the presence of selenium in the iron pyrites from Kraslitz. In 1820 he went to the University of Marburg to study medicine. While there he did not, however, neglect the study of chemistry. He was at that time particularly interested in an investigation on certain cyanogen compounds. In 1821 he went to Heidelberg, and in 1823 he received the degree of Doctor of Medicine. L. Gmelin became interested in him, and it was largely due to Gmelin's influence that Wöhler gave up his intention of practicing medicine, and concluded to devote himself entirely to chemistry. For further instruction in his chosen science, Wöhler went to Stockholm to receive instruction from Berzelius, in whose laboratory he continued to work from the fall of 1823 until the middle of the following year. Only a few years since, in a communication entitled "Jugenderinnerungen eines Chemikers," he gave a fascinating account of his journey to Stockholm and his experiences while working with Berzelius. On his return to Germany, he was called to teach chemistry in the recently founded municipal trade school (Gewerbschule) at Berlin. He accepted the call, and remained in Berlin until 1832, when he went to Cassel to live. In a short time he was called upon to take part in the direction of the higher trade school at Cassel. He continued to teach and work in Cassel until 1836, when he was appointed Professor of Chemistry in Göttingen. This office he held at the time of his death, September 23, 1882. In 1825 Wöhler became acquainted with Liebig, and an intimate friendship resulted, which continued until the death of Liebig, a few years ago. Though they lived far apart, they met during the vacations at their homes, or traveled together. Many important investigations were conceived by them as they talked over the problems of chemistry, and many papers appeared under both their names, containing the results of their joint work. Among such papers may be mentioned: "On Cyanic Acid" (1830); "On Mellithic Acid" (1830); "On Sulphotartaric Acid" (1831); "On Oil of Bitter Almonds, Benzoic Acid, and Related Compounds" (1832); "On the Formation of Oil of Bitter Almonds from Amygdalin" (1837); and "On Uric Acid" (1837). Of the papers included in the above list, the two which most attract attention are those "On the Oil of Bitter Almonds" and "On Uric Acid." In the former it was shown for the first time that in analogous carbon compounds there are groups which remain unchanged, though the compounds containing them may, in other respects, undergo a variety of changes. This is the conception of radicals or residues as we use it at the present day. It cannot be denied that this conception has done very much to simplify the study of organic compounds. The full value of the discovery was recognized at once by Berzelius, who, in a letter to the authors of the paper, proposed that they should call their radical proin or orthrin (the dawn of day), for the reason that the assumption of its existence might be likened to the dawn of a new day in chemistry. The study of this paper should form a part of the work of every advanced student of chemistry. It is a model of all that is desirable in a scientific memoir. The paper on uric acid is remarkable for the number of interesting transformation products described in it, and the skill displayed in devising methods for the isolation and purification of the new compounds. Comparatively little has been added to our knowledge of uric acid since the appearance of the paper of Liebig and Wöhler. It would lead too far to attempt to give a complete list of the papers which have appeared under the name of Wöhler alone. In 1828 he made the remarkable discovery that when an aqueous solution of ammonium cyanate, CNONH4, is evaporated, the salt is completely transformed into urea, which has the same percentage composition. It would be difficult to exaggerate the importance of this discovery. That a substance like urea, which up to that time had only been met with as a product of processes which take place in the animal body, should be formed in the laboratory out of inorganic compounds, appeared to chemists then to be little less than a miracle. To-day such facts are among the commonest of chemistry. The many brilliant syntheses of well-known and valuable organic compounds which have been made during the past twenty years are results of this discovery of Wöhler. In 1823 he published a paper on secretion, in the urine, of substances which are foreign to the animal organism, but which are brought into the body. He discovered the transformation of neutral organic salts into carbonates by the process of assimilation. In 1832 he investigated the dimorphism of arsenious acid and antimony oxide. In 1841 he made the discovery that dimorphous bodies have different fusing points, according as they are in the crystallized or amorphous condition. Among the more remarkable of his investigations in inorganic chemistry are those on methods for the preparation of potassium (1823); on tungsten compounds (1824); the preparation of aluminum (1827); of glucinum and yttrium (1828). In 1856, working with Ste. Claire Deville, he discovered crystallized boron. Analytical methods were improved in many ways, and excellent new methods were introduced by him. Further, he did a great deal for the improvement of the processes of applied chemistry. With Liebig he was associated in editing the "Annalen der Chemie and Pharmacie" and the "Handwörterbuch der Chemie." He wrote a remarkably useful and popular "Grundriss der Chemie." The part relating to inorganic chemistry appeared first in 1831, and was in use until a few years ago, when Fittig wrote his "Grundriss" on the same plan, a work which supplanted its prototype. The above will serve to give some idea of the great activity of Wöhler's life, and the fruitfulness of his labors. While thus contributing largely by his own work directly to the growth of chemistry, he did perhaps as much in the capacity of teacher. Many of the active chemists of the present day have enjoyed the advantages of Wöhler's instruction, and many can trace their success to the impulse gathered in the laboratory at Göttingen. The hand of the old master appears in investigations carried on to-day by his pupils. Wöhler's was not a speculative mind. He took very little part in the many important discussions on chemical theories which engaged the attention of such men as Dumas, Gerhardt, Berzelius, and Liebig, during the active period of his life. He preferred to deal with the facts as such; and no one ever dealt with the facts of chemistry more successfully. He had a genius for methods which has never been equaled. The obstacles which had baffled his predecessors were surmounted by him with ease. He was in this respect a truly great man. Personally, Wöhler was modest and retiring. His life was simple and unostentatious. He had a kindly disposition, which endeared him to his students, to which fact many American chemists who were students at Göttingen during the time of Wöhler's activity can cordially testify. In short, it may be said deliberately that Wöhler, as a chemist and as a man, was a fit model for all of us and for those who will come after us. Though he has gone, his methods live in every laboratory. His spirit reigns in many; could it reign in all, the chemical world would be the better for it. I.R. [1] See Kopp's "Geschichte der Chemie," iv., 440. LOUIS FAVRE, CONSTRUCTOR OF THE ST. GOTHARD TUNNEL. It is now already a year that the locomotive has been rolling over the St. Gothard road, crossing at a flash the distance separating Basle from Milan, and passing rapidly from the dark and damp defiles of German Switzerland into the sun lit plains of Lombardy. Our neighbors uproariously fêted the opening of this great international artery, which they consider as their personal and exclusive work, as well from a technical point of view as from that of the economic result that they had proposed to attain—the creation of a road which, in the words of Bismarck, "glorifies no other nation." As regards the piercing of the Gothard, the initiative does, in fact, belong by good right to the powerful "Iron Chancellor," so we have never dreamed of robbing Germany of the glory (and it is a true glory) of having created the second of the great transalpine routes, that open to European products a new gate to the Oriental world. It seems to us, however, that in the noisy concert of acclamations that echoed during the days of the fêtes over the inauguration of the line, a less modest place might have been made for those who, with invincible tenacity and rare talent, directed the technical part of the work, and especially those 15 kilometers of colossal boring—the great St. Gothard Tunnel, which ranks in the history of great public works side by side with the piercing of the Frejus, and the marvelous digging of Suez and Panama. We recall just now the names of those who, during nearly ten years, have contributed with entire disinterestedness to the completion of this colossal work. Over all stands a figure of very peculiar originality—that of M. Louis Favre, the general contractor of the great tunnel, whose name will remain attached to the creation of this work through the Helvetian Alps, like that of Sommeiller to the great tunnel of the Frejus, and that of De Lesseps to the artificial straits that henceforward join the oceans. Having myself had the honor of occupying the position of general secretary of the enterprise under consideration, I have been enabled to make a close acquaintance with the man who was so remarkable in all respects, and who, after passing his entire life in great public works, died like a soldier on the field of honor—in the depths of the tunnel. Louis Favre LOUIS FAVRE. THE DOWNFALL OF THE TITANS, CONQUERED BY THE GENIUS OF MAN. (Monument at Turin to Commemorate the Tunneling of the Alps.) I saw Favre, for the first time, in Geneva, in 1872, a few days after he had assumed the responsibility of undertaking the great work. He had been living since the war on his magnificent Plongeon estate, on the right bank of the lake. There was no need of dancing attendance in order to reach the contractor of the greatest work that has been accomplished up to the present time, for M. Favre was easy of access. We had scarcely passed five minutes together than we we were conversing as we often did later after an acquaintance of six years. After making known to him the object of my visit, the desire of being numbered among the personnel of his enterprise, the conversation quickly took that turn of mirthfulness that was at the bottom of Favre's character. "This is the first time," said he to me, laughing, "that I ever worked with Germans, and I had not yet struck the first blow of the pick on the Gothard when they began to quibble about our contract of the 8th of last August. Ah! that agreement of August 8th! How I had to change and re-change it, later on. If this thing continues, we shall have a pretty quarrel, considering that I do not understand a word of the multiple interpretations of their charabia. I ought to have mistrusted this. But you see I have remained inactive during the whole of this unfortunate war. I was not made for promenading in the paths of a garden, and I should have died of chagrin if such inaction had had to be prolonged. When one lives, as I have, for thirty years around lumber yards, it is difficult to accustom one's self to the sedentary and secluded life that I have led here for nearly two years." As he said, with just pride, Louis Favre had, indeed, before becoming the first contractor of public works in the world, lived for a long time in lumber yards. The years that so many other better instructed but less learned persons, who were afterward to gladly accept his authority, had given up to their studies, Favre had passed in the humble shop of his father, a carpenter at Chêne, a small village at a half league from Geneva. It soon becoming somewhat irksome for him in the village, he left the paternal workbench to start on what is called the "tour of France." He was then eighteen years of age. Three years afterward, he was undertaking small works. It was not long ere he was remarked by the engineers conducting the latter, and he was soon called to give his advice on all difficult questions. Between times, Favre had courageously studied the principal bases of such sciences as were to be useful to him. In the evening, he made up at the public school what was lacking in his early instruction; not that he hoped to make a complete study for an engineer, but only to learn the indispensable. He was, before all things, a practical man, who made up for the enforced insufficiency of his technical knowledge by a coup d'œil of surprising accuracy. Here it may be said to me that the piercing of the great St. Gothard Tunnel was accompanied by considerable loss. That is true, but it must be recalled also that this colossal work was accomplished amid the most insurmountable difficulties which ever presented themselves. In spite of this, the cost of the tunnel per running foot was also a third less than that of the great Mont Cenis Tunnel. When Favre undertook the St. Gothard, he already reckoned to his credit numerous victories in the domain of public works, especially in the construction of subterranean ones. The majority of tunnels of any length which, since the beginning of the establishment of railways, have been considered as works of some proportions (the Blaisy Tunnel, for instance), were executed by him, in addition to other open air works. So Favre reached the St. Gothard full of hope. The battle with the colossus did not displease him, and his courage and his confidence in the success of the work seemed to increase in measure as the circumstances surrounding the boring became more difficult. In the presence of the terrible inundation of the gallery of Airolo and the falling of aquiferous rocks, creating in the subterranean work so desperate a situation that a large number of very experienced engineers almost advised the abandonment of the works, Favre remained impassive. Amid the general apprehension, which, it may be readily comprehended, was felt in such a situation he made his confident and cheerful voice heard, reviving the ardor of all, and speaking disdainfully of "that insignificant Gothard, which would come out all right." The personnel of the enterprise were not the only ones, however, who were uneasy over the constantly occurring difficulties in the way of the work, for the company itself and the Swiss Federal Council made known to Favre their fears that the execution of the work would be delayed. He, however, calmed their fears, and exposed his projects to them, and the seances always ended by a vote of confidence in the future of the undertaking. Favre certainly did not dissimulate the difficulties that he should have to conquer, but he execrated those who were timorous and always tried to put confidence into those who surrounded him. But, singular phenomenon, he ended by deceiving himself and, at certain times, it would not have been easy to prove to him that the St. Gothard was not the most easy undertaking in the world. Those who have lived around him know the jokes that he sometimes made at the expense of poor Gothard, which paid him back with interest, however, and did not allow itself to be pierced so easy after all. Such confidence as existed in the first years, however, was not to exist for ever. The tunnel advanced, the heading deepened, but at the price of what troubles, and especially of how many expenses! Day by day one could soon count the probable deficit in the affair and the silent partners began to get a glimpse of the loss of the eight millions of securities that had had to be deposited with the Swiss Federal Council. For Favre personally the failure of the enterprise would have been ruin for his fortune was not so large as has been stated. To fears which Favre possessed more on account of the associates that he had engaged in the enterprise than for himself, came to join themselves those troubles with the Germans that he had spoken to me about on the first day. The St. Gothard Company, whose troubles are so celebrated, and whose inactivity lasted until the reconstruction of the affair, was seemingly undertaking to make Favre, who was directing the only work then in activity, bear all the insults that it had itself had to endure. And yet, amid these multiple cares, the contractor of the tunnel did not allow himself to become disheartened. Constantly at the breach he lived at his works, going from the gigantic adit of Goschenen to the inundated one of Anolo, constantly on the mountain, having no heed of the icy and perilous crossing, and passing days in the torrential rain that was flooding the tunnel. Who of us does not picture him in mind as he reached the inn at night, with his high boots still soaking wet, and his gray beard full of icicles to take his accustomed seat at the table, and, between courses, to tell some story full of mirth, some joke from the other works whence he had come, which made us laugh immoderately, and brought a smile to the faces of the German engineers. It is a singular coincidence that this confidence in his own work, despite all the struggles borne, was shared likewise by another man than Favre—by Germano Sommeiller, the creator of the Mont Cenis Tunnel. When the work of the first piercing of the Alps was yet in the period of attacks and incredulity, Sommeiller wrote his brother the following letter: "Always keep me posted my dear Leander, as to what the laughers are saying and remember the proverb that 'he will laugh well who laughs last!' The majority of the people, even engineers, are rubbing their hands in expectation of the colossal fiasco that awaits us, and it is for that that the envious keep somewhat silent. I will predict to you that as soon as success is assured everybody will mount to the house tops and say 'I told you so! It was an idea of my own!' What great geniuses are going to spring from the earth! I am in haste, so adieu, courage, energy, silence and especially cheerfulness! And especially cheerfulness!" Perhaps this cheerfulness of strong minds is the invincible weapon of those who, like Sommeiller and Favre, fight against apathy or the bad faith of their adversaries! Like Favre however Sommeiller had not the pleasure of being present at the consecration of his glory, for at the Mont Cenis banquet as at the St. Gothard the place reserved for the creator of the great work was empty. As disastrous as was the enterprise from a financial point of view what a triumph for Favre would have been the day on which he traversed from one end to the other that 15 kilometers of tunnel that he had walked over step by step since the first blow of the pick had struck the rock of the St. Gothard! But such a satisfaction was not to be reserved for him. Suddenly, on the 19th of July,...