agrees with those of albumenoid bodies. In the subjoined analyses, I represents the substance prepared from the skin of a rabbit; 2, from that of an ox; 3, the same, redissolved in ammonia, and re-precipitated by acetic acid. No. I. 54.61 6.94 14:48 No. 2. 54'62 6172 14'31 No. 3. 54'37 Carbon Hydrogen Nitrogen In an analytical point of view, these researches show the method of isolating certain animal or vegetable principles by submitting them to the action of the following reagents, of progressively increasing energy :-Ammonia, ammoniuret of zinc, and ammoniuret of copper. In this manner, albumenoid matters soluble in ammonia alone are separated from those which, like the tissue of the conjunctive, dissolve in it in the presence of the oxide of zinc. Those matters, again, which are insoluble in the two former liquids, but soluble in cupro-ammoniacal liquid, such as silk, are separated by means of the latter. Other substances of the same group, such as wool, insoluble even in the cupreous liquid, are untouched by any of these treatments. PATENTS. ABRIDGMENTS OF PROVISIONAL AND COMPLETE SPECIFICATIONS. DELIVERED FROM OCTOBER 5 TO OCTOBER II, 1872. Improvements in treating liquors containing ammoniacal compounds in order to obtain products therefrom. James Young, Kelly, Renfrew, N.B. October 10, 1872.-No. 2988. The feature of novelty which constitutes this invention is the heating in a still or boiler the solution of muriate of ammonia resulting from the production of carbonate or bicarbonate of soda by the ammonia process, mixed with the carbonate or carbonates of lime and magnesia, in order to obtain ammonia combined or mixed with carbonic acid. Improvements in the manufacture of carbonate of soda. James Young, Kelly, Renfrew, N.B. October 10, 1872.-No. 2989. The feature of novelty which constitutes this invention is the passing of carbonic acid through a solution of sulphuret of sodium, the solution being kept at or near the boiling-point in close vessels. Improved means and apparatus for drying sewage, and other like substances. William Astrop, paper maker, 27, Oriel Road, Homerton, Middlesex. October 10, 1872.-No. 2991. This invention relates especially to the separation of the liquid from, and the drying of the solid portion of the sewage or other like substance. The solid is separated from the liquid matter by precipitation in the ordinary settling tanks used for such purpose, but preference is given to those in which a partial vacuum is employed under the false bottom of such settling tank. The solids are dried by means of a centrifugal machine, the cage of which may be lined internally with felt cloth, or other suitable permeable material, and which is fitted with suitably arranged and contrived blades or scrapers which prevent the concretion of the solid matter on the sides of the cage. A brush or brushes, made to revolve or reciprocate with the motion of the cage, keep the meshes of the gauze of which it is composed clear of solid matter." Improvements in obtaining acetic acid. John Steedman, of the firm of Steedman and McAlister, manufacturing chemists, Glasgow, Lanark, N.B. October 11, 1872.-No. 3003. This invention consists in passing the vapour of the impure acid as obtained by processes heretofore in use through a hydrocarbon, or through an oil or fat; such hydrocarbon, oil, or fat being maintained at a temperature at least equal to that of the acetic acid vapour, and sufficient to liquefy it. Improvements in the treatment of coal-gas tars, for the purpose of obtaining certain useful products therefrom. Charles Lowe, manufacturing chemist, Reddish, Lancaster. October 11, 1872.-No. 3005. This invention relates to obtaining carbolic, cresylic, and other acids from London coal-tar, or similar substances. Improvements in the separation of substances and products capable of being employed for the purposes of dyeing and printing. Edward Chambers Nicholson, Herne Hill, Surrey. October 11, 1872.-No. 3007. This invention relates to the separation of what is known as rosaniline base from other products and compounds, which are either formed during its formation or subsequently in effecting its liberation. Rosaniline base is obtained, as is well understood, by firstly heating together aniline, videlicit, what is known as commercial aniline, with a solution of arsenic acid, in such a manner as is described in the Provisional Protection granted to me, No. 184, and dated January 25, 1860, or otherwise, in order that the desired compounds of rosaniline base shall be formed, which, together with arsenious acid and the excess of or the undecomposed arsenic acid and other products, will constitute what is technically known as the melt." The melt thus or otherwise obtained is dissolved in water and the compounds of the rosaniline base, in solution or otherwise, are decomposed by means of a stronger base, such, for example, as lime, and the liberated base is separated from the insoluble products thus resulting by solution in water heated to the boiling-point under the ordinary or normal pressure; the solution of the rosaniline base is allowed to cool, and the crystals deposited are collected and utilised for the production of dyes or colours, as is well understood. The rosaniline base thus or otherwise separated and obtained is found to possess but a slight solubility in water boiling at the ordinary or normal pressure, consequently a very large proportion of water is required to effect the solution of a small proportion of the base. In practice it being found that I lb. of the base is obtained from a solution of about 60 gallons of water. Now my invention consists in effecting the solution of the so-called rosaniline base or magenta base obtained or resulting from the processes herein before mentioned or otherwise obtained in water heated under pressure, whereby a greater solubility of such base is obtained, and consequently the amount of water necessary for effecting the solution of a given quantity of such base is very much diminished. In carrying out this invention I take the melted mass resulting from the cally known as the "melt" to a rough powder by means of edge rollers foregoing or other similar processes and reduce that which is technior otherwise, and I mix the same, either during such process of grinding or subsequently, with caustic lime, either hydrated or otherwise, and in such quantity as shall suffice to neutralise any acid and liberate transfer together with water into a suitable apparatus or boiler capable the rosaniline or magenta base. Such mixture or product I then of withstanding an elevated pressure, to which I apply heat. The desired solution having been obtained by reason of the elevation of the pressure and consequent increase of temperature. The solution or the contents of the boiler may be transferred, either before or after subsidence, to another vessel, wherein the separation of the rosaniline and magenta base thus extracted may be effected. Should the rosaniline or magenta base not be fully extracted by the first treament by means of water heated under pressure the treatment may be repeated. Improvements in the method of and apparatus for separating the soluble constituents of substances from the insoluble constituents. Samuel Henry Johnson, F.C.S., chemist, Lea Bank Works, Stratford, Essex. October 12, 1872.-No. 3014. According to this provisional specification the material to be operated on is placed in a suitable vessel, and the solvent is forced upwards through it entering near the bottom and being drawn off near the top. The spent material is then forced out by a plunger through a tubular passage; the compressed material in this passage plugs it and prevents the solvent passing. NOTES AND QUERIES. Zinc Powder.-Can you tell me where I can get, or how make "finely-granulated zinc" (as fine, or finer, than Calais sand)?— R. A. R. Deodorising Naphtha.-Would you be kind enough to state in your next issue if there is any method of removing the smell from naphtha, or torch-oil, without losing any of its illuminating powers or burning properties?-PETER TRUMBLE. Crystallising Pan for Nitrate of Lead.-Can you inform me what is the best kind of vessel for evaporating a solution of nitrate of lead, in a large quantity, for the purpose of crystallising; and whether the heat of steam, or of fire, direct, is the best for this purpose?— CONSTANT SUBSCRIBER, Experiments with the Torsion-Rod for Determining the Mean Density of the Earth," forming vol. xiv. of the Memoirs of the Royal Astronomical Society. By Francis Baily, Esq., Vice-Presi dent of the Society. London. 1843. P. 7 (referring to Cavendish's experiment).-"Yet, notwithstanding the precautions which he had taken, he still met with some anomalies for which he could not satisfactorily account, and which appear to have affected the results rather more than he had anticipated." See p. 10 for good description of the room. See pp. 23-24 for description of the scale and telescope. A good plan. P. 26.-" The 2 inch and the 2 inch lead balls were gilt and burnished, in order to prevent any radiation of heat from the surface." P. 31.-" if the slightest change of temperature be applied near the side of the torsion-box, or if either side near the balls be sprinkled with a little spirit of wine, the torsion-rod is immediately put in motion, and the resting-point undergoes a rapid change." P. 35.-" the mean increase of temperature has been only 0'15° F. per hour. Now, when it is considered that I am always obliged to remain in the room during the whole time of any experiments, and that a lamp is occasionally necessary for observing the microscopes, this change of temperature is of no great amount; nor, indeed, does it produce any anomalous effect on the motion of the torsion-rod. For I have generally noticed that anomalies arising from this source seldom occur except when sudden changes of temperature are produced in the torsion-box; and then only when one side of the torsion-box is more affected than the other, which seldom occurs in the ordinary state of the atmosphere." P. 36.-"Both of these experimentalists" (Cavendish and Reich), "in the pursuit of their enquiries, met with anomalies for which they could not satisfactorily account; and although Cavendish suspected the cause of some of these anomalies, and even undertook a few experiments for the express purpose of discovering it, yet he does not appear, either then or at any future time, to have pursued the subject further, nor to have applied any remedy for the evil in any of his subsequent experiments. He closes the account of his thermometrical experiments with the following laconic remark:-'It seems sufficiently proved, therefore, that the effect in question is produced by the difference of temperature between the weights and the case.' He probably considered that the amount of the disturbing force, although very sensible when tried in the extreme cases which he pursued, yet under the ordinary circumstances of temperature was too minute to lead to any material error in the results, and therefore abandoned the attempt to remove it; for he says. It, indeed, may be objected that, as the result appears (for this quotation see Cavendish's original paper, CHEMICAL NEWS, vol. xxvii., p. 210) 1-14th of the whole.' Had Cavendish, however, increased the number of his experiments, he would soon have discovered the error of his opinion, and that it would be absolutely necessary to remove altogether, or at least to modify, this disturbing force before he could place any dependence on the result of his labours." P. 37.-"Although Reich pursued his experiments in a room which was rather more favourably situate than the outhouse of Cavendish, yet it appears that this distinguished experimentalist also experienced anomalies for which he has not given any satisfactory explanation. Indeed, he does not describe the nature of those anomalies. But at the end of his work he subjoins the following passage, which bears upon the point in question, to which I am desirous of drawing the attention of the reader:- Totally different from these gradually progressive changes in the times of vibration, and also easily to be distinguished therefrom, were the still much greater anomalies that were occasionally observed, and which were produced by a small obstruction that was opposed to the vibrating arm. It is probable that small hairs or filaments caused by foulness had introduced themselves into the narrow case, and which immediately produced much shorter periods of vibration, greater irregularities in them, and a rapid decrease of the arc of vibration. Whenever this happened, the case was carefully cleaned: that is to say, all the filaments that were in the narrow tube through which the wire that supported the balls passed, were destroyed by means of a burning flame passed through it.' Now, it is difficult to understand how these occasional interruptions could have taken place at such short intervals, after the tube had been once properly cleaned and closed; and as no other allusion to such disturbances has been made in the account of the experiments that appear in the book, not only a doubt naturally arises as to the nature and magnitude of the anomalies, and the precise manner in which the results were affected, but a suspicion also is entertained that some of the experiments thus alluded to may have been rejected, on account of their presumed discordance." MONDAY, 12th.-Geographical, 8.30. London Institution, 4. MEETINGS FOR THE WEEK. Civil Engineers, 8. WEDNESDAY, 14th.-Society of Arts, 8. Geological, 8. TUESDAY, 13th.-Royal Institution, 3. J. H. Parker, "On Roman History and Architecture." THURSDAY, 15th.-Royal Institution, 3. Prof. Tyndall, "On Light." SCALE OF ANALYTICAL FEES, Post Free on application. PHILIP HARRIS & CO., Manufacturing Wholesale and Retail Chemists, BULL RING, BIRMINGHAM. TEXT-BOOKS OF SCIENCE EDITED BY T. M. GOODEve, m.a., AND C. W. MERRIFIELD, F.R.S. Just published, in small 8vo., price 3s. 6d. cloth, Electricity and Magnetism. By Fleeming JENKIN, F.R.SS. L. & E., Professor of Engineering in the University of Edinburgh. Text-Books previously published, price 3s. 6d. each : GOODEVE'S MECHANISM. BLOXAM'S METALS. MILLER'S INORGANIC CHEMISTRY. GRIFFIN'S ALGEBRA AND TRIGONOMETRY. London: LONGMANS, GREEN, and CO., Paternoster Row. NOTES ON NATURAL PHILOSOPHY. By G. F. RODWELL, F.R.A.S., Lecturer on Natural Philosophy in Guy's Hospital, Science Master in Marlborough College. J. and A. CHURCHILL, New Burlington Street. NEWS Now ready, our New Revised CATALOGUE OF CHEMICALS AND CHEMICAL Terms moderate. APPARATUS, Also The LABORATORY will be open at 10 a.m. for Instruction in Practical Chemistry as applied to Pharmacy, Medicine, Analysis, &c. The CLASSES will meet as usual. The CHEMICAL and TOXICOLOGICAL CLASS on Monday and Thursday evenings at 8 p.m., commencing October 1st. The LATIN CLASS on Tuesdays and Fridays at 8 p.m., commencing October 2nd. The MATERIA MEDICA and BOTANICAL CLASS, every Wednesday and Saturday at 8 p.m., commencing October 3rd. The BOTANICAL GARDEN affords to Students desirous of acquiring a Practical Knowledge of Botany every facility for doing so. During the Season BOTANICAL EXCURSIONS are made every Saturday at 10 a.m. Fee to either of the above Classes Half-a-Guinea per Month. Pupils can enter at any period to either Classes or Laboratory. All Fees must be paid in advance. PRIVATE TUITION for the usual Examinations of the Society, the Modified Examination, &c. Letters of inquiry should be accompanied with a stamped envelope. Address-54, KENTISH TOWN ROAD, N.W. THE LIVERPOOL COLLEGE CHEMISTRY, 96, DUKE STREET, LIVerpool. Specially Devoted to the Study of CHEMISTRY, TECHNOLOGY and ASSAYING. OF Laboratories open throughout the Year. MARTIN MURPHY, F.C.S., &c., Principal (Successor to the late Dr. SHERIDAN MUSPRATT). A Special Laboratory is devoted to Commercial Analyses of every description, and to Mineral Assays. Manufacturers' and Smelters' Analyses and Assays undertaken on Contract. Patentees and Inventors Advised and Assisted. Works and Mines Inspected. The Erection of Manufacturers' Plant Supervised, &c. Terms and Fees VERY MODerate. Further Particulars and Full Prospectus on application to The Principal, MARTIN MURPHY, F.C.S. &c. THE CHEMICAL NEWS. VOL. XXVII No. 703 Having thus prepared silicon from flint, we are in a position to compare it with carbon, to trace out the analogies which subsist between them, and then to show that some of the alcoholic and other compounds of carbon + MAYOHOLS A DISCOURSE ON ALCOHOLS FROM FLINT have their strange and interesting analogues in a silicon series. AND QUARTZ.* By ProfessoÈMES REYNOLDS, M.D. FORD In appearing before you this evening to lecture on "Alcohols from Flint and Quartz," you will permit me at the outset to explain, and even materially to extend, the title of my discourse. I do not propose to show that spirits can be extracted from flint and quartz by mechanical processes; but I hope to satisfy you that by indirect and purely chemical means we can obtain from these familiar and widely-diffused minerals, and from native silicates, bodies resembling in chemical action, and even in appearance, the well-known alcohol of wine. which we directly obtain the silicon, as you see, by simply heating with some metallic sodium. In this case, the sodium replaces the silicon, the latter separating, as you observe, in the tube as a dark brown substance. Carbon has hitherto been considered the sole alcoholforming element; but we shall see that the chief constituent of flint and quartz, namely, silicon, must now be admitted to share in this power, and likewise in the ability to form other remarkable compounds that it will be necessary for me to refer to in the course of this lecture. In selecting this subject, I have done so in part because this most promising field of research, opened up by the labours of Wöhler, Buff, Friedel, Crafts, Ladenburg, and others, has hitherto been but little cultivated in this country, and therefore probably possesses some novelty for the audience I have the honour to address; and also because we find in this new branch of chemical investigation most interesting illustrations of the advantage we may derive from the cautious use of the argument from analogy. As a preliminary to the enquiry I propose, we may consider very briefly the chemical nature of Aint and quartz. The word "flint" is of very ancient origin, and was often used to indicate any particularly hard rock. In this sense it is employed several times in the Old Testamentfirst, in the book of Deuteronomy, viii., 15, and in Psalms, cxiv., 8, where the rock struck by Moses is said to be "of flint." We now use the term to distinguish a well-known uncrystalline mineral, which can be easily shown to be a chemical compound of two so-called elementary forms of matter-oxygen and silicon. Flint is identical in chemical composition with quartz or rock-crystal, though physically different, as you will perceive by reference to the fine specimens on the table, kindly lent by Mr. Bryce M. Wright, the well-known mineral collector. The common name of "silica" is given to the chemical compound, and the terms flint, agate, quartz, rock-crystal, are reserved for the forms in which we meet with this remarkable substance in nature. Having cleared our ground so far, we have to find how the oxygen may be separated from any of those forms of silica, and the element silicon may be obtained. This cannot be directly accomplished, but by indirect means we can obtain the desired results. I have here a quantity of finely-divided flint mixed with some powdered fluor-spar; when I pour oil of vitriol on the mixture, and apply heat, a colourless gas is obtained, which, when passed into water, produces a highly acid and gelatinous liquid. The gas is a compound of the element fluorine, with silicon -the tetrafluoride of silicon-and this, when brought in contact with water, produces an acid called hydrofluosilicic and a quantity of gelatinous hydrate of silica. The clear acid liquid, when treated with caustic soda, yields this white salt, the fluosilicate of sodium, from * Delivered before the Royal Institution, May 2, 1873. First, then, we shall compare the elements themselves. We meet with nearly pure carbon under the well-known forms of charcoal, graphite, and diamond. a number of other We can easily prepare the corresponding varieties of silicon-the amorphous, the graphitoidal, and adamantine. With the aid of the phengascope, I shall now project on the screen images of specimens, in order that you may compare the varieties side by side. I have also on the table a very fine specimen of crystallised silicon, for which I have to thank Messrs. Hopkin and Williams. [The lecturer showed a greatly magnified image of a fine crystallised diamond on the screen; specimens were exhibited in the same way.] As might be anticipated, the specific gravity of carbon is lowest in charcoal and highest in diamond. Corresponding differences in specific gravity are observed between the varieties of silicon. correspond remarkably in variations of specific heat, with different states of aggregation. The specific heat of the diamond is lower than that of graphite, and the specific heat of adamantine silicon is lower than that of the graphitoidal variety. The two elements also Passing now from the points of physical resemblance between carbon and silicon, I shall dwell more particularly on the chemical relations of the two elements. We are familiar with the fact that carbon burns in oxy. gen, producing, in an excess of that gas, the well-known gaseous oxide of carbon commonly called carbonic acid; charcoal or coke burn readily in oxygen, while graphite is consumed with considerable difficulty, and the diamond is still more difficult of combustion. Amorphous silicon burns as easily in oxygen as charcoal, and forms the oxide silica, the same oxide that we find as flint or quartz. [Experiments exhibited.] In this way we can reproduce, so far as composition is concerned, the substance from which we originally obtained the silicon for our experiments. Now, though amorphous silicon is easily burnt, the graphitic and adamantine varieties of the element resemble the corresponding forms of carbon in difficult combustibility. Crystalline silicon may be raised even to a white heat in oxygen gas without burning. Unlike carbon, silicon in any of its forms easily combines directly with chlorine, producing the liquid choride This is a very volatile body, which I have in this tube. boiling at 50° C., and is half as heavy again as water. It can also be prepared from silica by heating to full redness the finely-divided oxide and carbon in a current of chlorine. In composition this chloride is the silicon representative of tetrachloride of carbon. In addition to this chloride of silicon, the discovery of which we owe to Berzelius, another has very recently been obtained by Friedel, which corresponds to a wellknown carbon hexachloride. We next pass to a compound of silicon with hydrogen It may be prepared in a pure state by means of a rather complex reaction I shall have presently to refer to; but we can easily obtain the impure gas by Wöhler's method, in treating a compound of silicon and magnesium with hydrochloric acid. We thus obtain a colourless, sponlight on contact with the air. In its pure condition, silicitaneously inflammable gas, which burns with a bright uretted hydrogen is not spontaneously combustible at ordinary pressure, but in a slightly rarefied atmosphere it easily in flames. The compositions of these silicon and carbon compounds are shown in this table: CO2. C2C16. SiH4. Hydrides. The siliciuretted hydrogen is evidently the chemical analogue of marsh-gas, the tetrahydride of carbon. It is usual to regard marsh-gas as the typical carbon compound from which some alcoholic series may be supposed to spring, and, in fact, all the alcohols belonging to the group of which the well-known wood-spirit and spirit of wine are the chief members, are commonly regarded as derivatives of marsh-gas, in which a part, or all, the hydrogen has been replaced by one or more compound radicals, In these such as hydroxyl, methyl, ethyl, propyl, &c. cases, the carbon of the marsh-gas is the grouping element of the compound, or that constituent which serves to bind together the different materials of which the molecular edifice is constructed. In the same way, the silicon in siliciuretted hydrogen may be shown to be the nucleus round which can be grouped hydroxyl, methyl, ethyl, &c., so as to form the alcohols whose compositions I shall presently have to refer to. Several of the less complex terms are still wanting, but their existence is rendered highly probable by the occurrence of bodies bearing the same close relation to the unknown alcohol that marshgas bears to wood-spirit, or the acid of vinegar (acetic acid) to common spirit of wine. As we ascend in the series, however, we meet with the true alcohols, in which silicon takes the place of carbon as the grouping element. It must be here admitted, however, that no well-defined alcohols have yet been discovered in which silicon acts in any other way than as the nucleus of the compound; carbon radicals in all these cases playing the subordinate parts. But we have every reason to expect that complex alcohols containing silicon only will yet be obtained as researches extend. SiO2. SiCl4. Si2C16. Si In 1857 Buff and Wöhler obtained a volatile fuming liquid on heating crystalline silicon nearly to redness in a current of dry hydrochloric acid gas. The precise nature of this liquid was unknown until 1871, when Friedel and Crafts published the results of their admirable researches upon Buff and Wöhler's liquid, and showed that it was a mixture of chloride of silicon with a new body, which proved to be the strict chemical analogue of our wellknown chloroform, silicon replacing carbon. Chloroform. SiHC13. CHC13. This body is a colourless, mobile, and very volatile liquid boiling at 35° C. I have a quantity of it in this tube. One of its most remarkable properties is that of exploding with great facility when its vapour is mixed with air. I shall now show you the experiment. Ordinary chloride of silicon does not afford an explosive mixture when its vapour is mingled with air. [Experiments shown.] When this remarkable body is made to unite with anhydrous alcohol, a colourless ethereal liquid is obtained on distillation, having an agreeable odour, and a boilingpoint at 134° C. This body is strictly analogous in composition to a substance obtained by Williamson and Kay, by acting on ordinary chloroform with sodium alcohol. These ethers may each be regarded as derived from a glycerine or triatomic alcohol, as shown below. Neither of these alcohols have as yet been isolated. H OC2H5 OC2H5 (OC2H H OH OH (OH Oxides. Chlorides. Si H OC2H5 OC2H5 (OC2H5 H OH OH (OH Glycerins. By the action of sodium on the silicon ether just referred to we can obtain siliciuretted hydrogen in a state of purity. This is the only known mode of obtaining the pure compound. Returning to the silicon chloroform, about whose chemical nature we can now have little if any doubt, we next have to enquire in what direction, and how far, we can pursue the analogy between the great pain-killer, discovered almost simultaneously by Soubeiran and the illustrious chemist of Giessen, who has so recently passed away from amongst us, and the curious body that we can obtain indirectly from flint or other form of silica in the manner I have described. Ordinary chloroform is well known to be closely allied to common wood-spirit, or methyl alcohol, in a way that In fact, will be evident on comparing the formulæ. chloroform is easily obtained by treating wood-spirit with bleaching-powder. We cannot in any simple way reverse this process and prepare wood-spirit from chloroform, but we can do something in this direction, for we are able by the action of caustic potash to obtain from chloroform formic acid, a body which is one of the most remarkable products of oxidation of wood-spirit. The relation of formic acid to the alcohol is shown in the table below; and it is there further pointed out that this formic acid should yield an anhydride-a body capable of producing the acid by union with the elements of water. This anhydride is not known, but the importance of suggesting its existence will appear in a moment. OH H Si O он H Si O Methyl alcohols. Formic acids. Anhydrides. H CO O(SiOH) (O(COH) Regarding silicon-chloroform from the same point of view, analogy would lead us to look for a simple silicon alcohol similar to wood-spirit or methyl alcohol; but we would not expect the silicon-chloroform easily to yield this alcohol directly, though we would be justified in hoping that an acid corresponding to formic acid might be obtained. As a matter of fact, no such alcohol has as yet been prepared even indirectly; but a corresponding acid is very readily produced, and more than this, for the anhydride at present wanting in the carbon series is found in that of silicon. If I pass the vapour of silicon-chloroform into water nearly ice-cold, a white solid body is obtained without any evolution of hydrogen, and an acid liquid produced. The white solid then collected, washed, and dried at a low temperature, forms a white inflammable powder, which was first described by Buff and Wöhler. Friedel and Ladenburg have shown that this remarkable body is the anhydride of the silico-formic acid. According to the results of my own investigations, the acid liquid to which I referred just now contains, in addition to hydrochloric acid, the true silico-formic acid-a body possessing nearly as energetic reducing properties as the corresponding acid derived from wood-spirit. I shall now demonstrate these facts. [The lecturer then exhibited the experiments referred to.] It will naturally be asked whether the silicon chloroform is capable of acting as an anesthetic like ordinary chloroform. But it is only necessary to bear in mind the fact that it is very easily decomposed by water into gelatinous matter, and highly corrosive hydrochloric acid, in order to understand that its inhalation would be attended by the speedy destruction of the lungs of any person persisting in the experiment. Starting from silicon chloroform, then, we have been led, by analogical reasoning in the first instance, to infer the existence of a simple silicon alcohol precisely corresponding to wood-spirit. On testing this induction by experiment, we have obtained answers which are, so far as they go, altogether favourable to the view just stated. In fact, the results are as satisfactory as they can be short of the discovery of the silico-methyl alcohol. I shall now endeavour to strengthen this position by showing that the existence of three higher members of the alcoholic series has been rendered highly probable by the discovery of closely related bodies, though the alcohols themselves have not been isolated; and, finally, I shall show that the alcohols of still higher terms have actually been obtained. In the course of their elaborate and able investigation of silicon compounds, Friedel and Crafts discovered that chloride of silicon easily acts upon common alcohol as I have already mentioned, producing a body which Friedel and Ladenburg have recently shown to be easily attacked by a mixture of sodium with a curious substance contained in this tube-zinc-ethyl. The product, when treated with caustic potash, yields a body which bears the same relation to silico-propyl alcohol that formic acid does to wood-spirit. This relationship is shown in the formula(C2H5 (C2H5 H Si H Propyl alcohols. H C H You will observe that it is the silico-heptyl alcohol precisely corresponding to a simple carbon alcohol recently discovered by Nahapetian, both being tertiary alcohols. We owe to Ladenburg the discovery of this lowest known it is a colourless liquid, not unlike the ordinary alcohol term of alcohols containing silicon. As you can observe of wine. It is insoluble in water, but easily dissolved by spirit and ether. Chemically it acts just like any of the other alcohols, producing ethers, and dissolving the alkali metals to form sodium or potassium alcoholates. When common spirit burns you are aware that its flame is nearly colourless, but I shall now burn some of our alcohol from flint, and you will find, particularly when we feed the flame with oxygen, that a bright light is emitted. Clearly defined though this alcohol is, it does not stand alone, for at least one other compound of the same order is known. It was suggested in 1870, by Friedel and Crafts, that silicon ethide-a body easily prepared by the action of chloride of silicon on zinc ethide-might be regarded as the hydride of silico-nonyl, and should stand in the same relation to an alcohol that marsh-gas does to common wood-spirit, or ethyl hydride to ordinary alcohol. This happy idea, when put to the test of experiment, was fully justified by the result, for, on treating silicon ethide in essentially the same manner that we should adopt in preparing wood-spirit from marsh-gas, a colourless liquid, lighter than, and insoluble in, water is obtained. The boiling-point of this body is 190° C. It yields an ether with acetic acid, dissolves sodium, forming an alcoholate, and, in fact, conforms to the general habits of the alcohols of the series to which common spirit belongs. The compositions of these bodies are thus represented(C8H17 C8H17 H Si Nonyl hydrides. Si H OH Alcohols. It is thus shown to be precisely similar to the nonyl alcohol prepared by Pelouze and Cahours from American petroleum. Ladenburg has very recently advanced even beyond the point we have now reached, and has shown that the chloride of silicon can be made to yield two ethers, which correspond, as I may suggest, to silico-nonyl diatomic and triatomic alcohols. Thus Having, therefore, grounds for inferring the existence of silico-propyl, silico-amyl, and silico-hexyl alcohols, I shall now pass at once to the second class of evidence, and show that the alcohols of still higher terms can actually be prepared. In referring to the preparation of silico-propionic acid, it was stated that when chloride of silicon acts upon absolute alcohol a body is obtained which, on treatment with zinc-ethyl and sodium, yields an ethereal product from which silico-propionic acid can be obtained by treatment with caustic potash. If, however, instead of using the caustic alkali we continue the action of zinc |