NEWS 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 H Si H Propyl alcohols. Propionic acids. (C2H5 H C H OH (C2H5 CO OH 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 H Si H The researches of Friedel and Crafts have made us acquainted with a body which may also probably be regarded as the hydride corresponding to silico-hexyl alcohol. This compound is prepared by the action of zincmethide and zinc-ethide in chloride of silicon. 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 NEWS iodide, and bromide of silicon, and treatment of the hexa- | practical value of scientific research is rarely apparent at iodide with zinc-ethyl enables us to obtain the ethide whose formula is given in this table It is not improbable that in the last-named compound we have the starting-point of a new series of still more complex bodies, analogous to derivatives of olefiant-gas rather than to those of marsh-gas. I trust you will now admit that the case I proposed to lay before you has been made out-namely, that we can obtain some alcohols indirectly from flint or other form of silica, and that we have solid ground for inferring the existence of many others. A rich and beautiful field for chemical research appears to lie before us in tracing out the analogies between the compounds of carbon and silicon, and recognising the chemical representatives of many of the most complex "organic compounds" in the native silicates which form so large a part of the crust of this earth. Hitherto in this lecture I have avoided reference to subjects not directly connected with the matter in hand, but, before concluding, I would refer, necessarily in a very few words, to some enquiries in this department of chemistry which have been carried on in the laboratory of the Royal Dublin Society. First, however, allow me to perform an experiment. I have here a glass jar filled with dry ammoniacal gas; when I drop into it some chloride of silicon, a white compound is obtained. This body was discovered by Persoz in 1830, and the composition he assigns to it would, as ably suggested by Dr. Hofmann, represent a mixture of sal-ammoniac with the hydrochlorate of silicon-guanidine. If this white body be ignited strongly in a closed vessel, an infusible white substance remains, which has been examined by Deville and Wöhler, who have shown that it contains silicon and nitrogen, and that the same or similar body can be produced by intensely heating crystalline silicon in an atmosphere of nitrogen. My examination of this curious body has led me to the conclusion that it is the silicon analogue of cyanogen-a well-known compound of nitrogen with carbon, and the chief constituent of the deadly poison prussic acid. This body, though little affected even at a very high temperature, in the absence of moisture is easily decomposed by steam-silica, ammonia, and hydrogen resulting. A similar decomposition is effected by heating with sodalime. I may add that, when this singular compound is fused with a small quantity of carbonate of potassium, cyanide and silicate of the metal are produced; in this case, carbon appears to displace silicon." If, in the experiments with ammoniacal gas, we substitute silicon-chloroform for the silicic chloride, a body is obtained from which this compound of silicon and nitrogen can be easily extracted. Now we know well that when ordinary chloroform is heated with ammonia gas, chloride and cyanide of ammonium are obtained, and that under certain circumstances a body called paracyanogen is also produced. Analogy would lead us to anticipate that silicon-chloroform would react in a similar manner, and the facts I have hitherto observed justify this inference. It would be out of place to pursue this subject here, as the results of the enquiry referred to have not yet been published. I have, therefore, now simply shown to you one of the chief bodies to which interest belongs, and ventured to point out the relationship I believe it to bear to some of the well-known and remarkable compounds of carbon with nitrogen. In concluding this lecture, I need simply remind the audience I have the honour to address that the first. Who could have suspected that the benzole discovered by the venerable philosopher whose name is so inseparably connected with this Institution, would have proved, in the able hands of Perkin and of Hofmann, the chief source of many of the exquisite dyes now largely manufactured in this country? Yet in this, as in a hundred of other instances, the small and apparently useless scientific seedling has gradually expanded into the strong tree, yielding its rich store of useful fruit. Let us hope that a similar future awaits some of the alcohols from flint which have been referred to this evening, and that, in pursuing our studies of the silicon analogues of the more complex carbon compounds, we may be led to appreciate more fully than we have hitherto done the admirable economy and harmony of Nature. he shows that the apparent profit of £1324 is in reality a In speaking of the Lodge Irrigation Farm, near Barking, loss of £157! "As far as I have observed," says the author, "almost all calculations upon the profits of sewageirrigation farms in England have been drawn up in the same manner. Mr. Samuelson, M.P. for Banbury, with whom I had a very detailed conversation on the sewage question, informed me that he did not believe in the profitable working of a single sewage farm in England, notwithstanding all calculations as to apparent gain." He also quotes the following significant passage from the Birmingham report:-"It would be utterly irrational to expect anything but loss, even though the sewage itself may possess considerable manurial value." "The In Banbury, again, M. Lefeldt finds an imaginary gain of £59 12s. 10d., which on close examination turns out to be a loss of £466, without any charge for the sewage. The account of the Edinburgh irrigation meadows contains a most important fact: if the sewage-water is allowed to flow upon the land until two days before mowing, the growth is found most luxuriant, with the single drawback that cattle refuse to eat the grass. capillary tubes for some inches above the roots are found to be filled with unassimilated foecal matters." Is it not, then, perfectly possible that the vegetables from irrigation farms may be contaminated in like manner? Man, at least in a state of civilisation, does not possess the instincts which warn cattle against such dangerous food. Is it prudent to uphold a system of agriculture which may thus introduce the germs of zymotic disease and the ova of entozoa into the human frame? "The city," says the author, "derives no pecuniary advantage from irrigation, and the authorities, as far back as 1839, proposed the abolition of the system, as the emanations from the land were by some persons considered unwholesome. At Carlisle, where the sewage is disinfected with carbolic acid previous to being used for irrigation, the author met with no complaints of offensive effluvia, and hence he recommends some such previous treatment as very desirable. Concerning the emanations of irrigation farms where no previous treatment is applied to the sewage, we find it *Der Gegenwaertige Stand der Abfuhr und Kanalisationsfrage in Grossbritannien. Berichte au Se. Excellenz, den Kgl. Preuss. Minister Lefeldt, Civil Ingenieur in Schoeningen. Berlin: Wiegandt and fuer die Landwithschaftlichen Angelegenteiten Erstattet," von W. Hempel. 1872. NEWS recorded that-" The landlord of the Peto Arms, near Barking Station, Mr. Jesse Bailey, declared that at times, especially on warm summer days when the wind blew direct from the Lodge Farm, the fumes were very unpleasant, although the distance is nearly a mile." Again-"The deposits of the notorious settling-tanks, and their entire vicinity, diffused truly mephitic odours. Even on the celebrated Breton Farm (Mr. Hope's) I experienced this, on my second visit, in the most horrible sense of the word." bead becomes quite clear and paler, showing the same spectrum, but while hot showing the band a, as in Fig. 2. A further addition of 10 per cent of sodium carbonate causes the bead to remain a dark purple when cold, and exhibiting the complete spectrum of Fig. 2. When 25 per cent has been added a blue bead results, and the spectrum in Fig. 2 changes; the band marked ẞ is perceptibly lowered, overlapping D, as in Fig. 3, but the band y remains as in Fig. 2. If 5 per cent more is taken up, the three absorption bands are like those drawn in Fig. 3, which represents cobalt dissolved in borax. The bead is now The author considers that, where irrigation is adopted, an acre of land should be arranged to receive the secretions of every twenty to thirty-five persons. On this scale Birmingham would require a sewage farm of from 10,000 (Mr. Hope's estimate) to 13,000 acres, whilst London would require a snug little plot of some 150,000 to 200,000 FIG. I. acres. Well may M. Lefeldt exclaim-"That for large cities a vast tract of land, and a gigantic capital for purchase, preparation, and management, would be requisite, is so self-evident as scarcely to require mention." He adds "The difficulty of irrigation lies here, that the purification and the economical application of the sewage FIG. 2. must go hand in hand. Purification alone, with a total disregard of expense, is quite practicable; economic utilisation alone is also attainable in favourable cases. But the irrigation farmer is compelled to take and to purify the sewage when he can make no use of it-in rainy weather and in winter." Such is the light in which sewage appears in the eyes of a disinterested and intelligent stranger. Surely we ought to pause before giving so unsatisfactory a system legal sanction. FIG. 3. FIG. 5. It is well known that certain substances may be identified FIG. 8. Since Capt. Ross has lately proposed boric acid as a valuable flux for estimating the alkalies quantitatively, when combined with cobalt, and since my own experi- FIG. 9. ments lead me to confirm some of his conclusions, I shall therefore begin at once with an account of these results. When cobalt oxide is added to boric acid, and strongly fused for two or three minutes in the inner flame, using gas as a source of heat, the cold bead possesses a dull blue colour, and is almost opaque. However, by using a powerful light we can see it gives a spectrum of three very faint bands, nearly in the same position as shown in Fig. 2; if, now, I per cent of sodium carbonate be taken up, and the bead treated as before, when cold, the colour is a murky reddish-purple, and the spectrum no longer giving the band in the red, but two obscure absorption bands, very close together, and a slight shading at F, as shown in Fig. 1. Upon adding 4 per cent of soda the very dark, and requires pressing, whilst hot, between the Fig. 4 represents the spectrum of a salt of magnesia | Chemical Geology, and his papers were always marked when moistened with solution of cobalt. It is a single band, with a good deal of shading in the green and blue. Fig. 5 is the spectrum of the indigo-blue compound of calcium oxide when treated with cobalt. The application of the blowpipe flame is not requisite to fulfil this reaction, the colour appearing the same instant the solution is applied. Its spectrum shows the two bands very distinctly, especially the one in the red, and there is some shading in the green. Fig. 6 is the interesting spectrum of the bright blue compound of alumina. These three bands, although generally faint, are narrow and well defined, the blue and green spaces being invariably clear. Websterite and cryolite show this spectrum to great advantage. With regard to silica, I have not, as yet, been able to form a compound giving a characteristic spectrum to be available as a means of detection in small quantities. Pure silica, as pointed out by Capt. Ross, turns purple when acted on | by cobalt. This gives a spectrum very similar to the alumina compound, except in regard to the band in the green, which is not nearly so well defined. But in mixtures, as in minerals, this reaction is of no use. Sodium carbonate dissolves silica until there results a clear bead; when cobalt is added it assumes a deep indigo, and gives a spectrum of three sharply-defined dark bands, somewhat resembling those in the borax compound, only the band in the green being more refrangible, and therefore the most characteristic. The beautiful green compound of oxide of zinc which is occasionally used as a pigment, and known as Rinman's green, gives the spectrum pourtrayed in Fig. 7. The last compound to which I shall now draw attention is sodium carbonate and boric acid. When a thin soda bead is formed with a mere fragment of boric acid, and fused along with a little cobalt, in the outer flame, the bead while hot is of a deep orange-brown colour, turning nearly black and opaque on cooling, but before becoming quite cold rapidly crystallises and turns green. By transmitted light the whole of the blue is cut off and part of the red, while a narrow band is visible at the yellow end of the green. If the bead, however, be submitted to the action of the inner flame, it turns a pale blue while hot, and crystallises on cooling to a pale pink by transmitted light, and assuming a lavender tint by reflected light. This unique spectrum of the pink bead is depicted in Fig. 8; and fig. 9 represents the flame spectrum of boric acid, consisting of four bright bands. The following are the numerical values of the several absorption bands, according to Mr. Sorby's ingenious method of notation (Proc. R. S., vol. xv., p. 434): Fig. 1 a=41, B=3% a=2,B=41 Fig. 3 Fig. 4 Fig. 5 Fig. 7 OBITUARY. JAMES WALLACE YOUNG. JAMES WALLACE YOUNG, aged 30, died at Portobello, on the 12th inst. He was an ardent student of Chemistry of great promise, and was a not infrequent contributor to these pages. His researches were mostly in the field of by close reasoning and his analyses by minute accuracy. earthly ambition was to be a good chemist and microOf a disposition the most kindly and modest, his only scopist. How far he succeeded in both of these objects is shown by many careful analyses published in these the fine collection of rock sections which he had for years pages, while his enthusiasm as a microscopist is shown in been engaged preparing during his spare hours. CORRESPONDENCE. DETERMINING FAT IN MILK. To the Editor of the Chemical News. SIR,-In a letter which I wrote to you by last mail, I mentioned the difficulty I had lately met with in determining the weight of the fat in milk. A borate mis-called ether, but consisting really of a mixture of water, alcohol, and ether, was the cause of the failure. I had every reason to suppose the ether good, and in a cold climate the defect would at once have proclaimed itself, but, working as I am at 90° to 92° F., a very little ether suffices to give a strong ethereal smell to a very poor mixture. Below I send you a description of the method I have lately used for the estimation of fat in milk. I dont know successful one. I am, &c., if it is a new one, anyhow I find it a very ready and Medical College, Calcutta, April 4, 1873. F. N. MACNAMARA. drawn out one end, introduce 10 c.c. of milk and an equal CHEMICAL NOTICES FROM FOREIGN Under this heading will be found an encyclopædic list of NOTE. All degrees of temperature are Centigrade, unless otherwise expressed. Comptes Rendus Hebdomadaires des Séances de l'Academie des Sciences, April 28, 1873. Manufacture of Sulphate of Ammonia from Nitrogenous Refuse.-L. L'Hote.-The refuse is treated with a dilute solution of caustic soda, either in the cold or at a very gentle heat. A solution or disagregation of the is made into a paste with slaked lime, and the mass is matter is thus obtained. The viscid liquid thus obtained with receivers containing chamber acid. It is distilled at then introduced into a cast-iron retort communicating NEWS the lowest possible temperature to avoid decomposition of the ammonia. When all liberation of gas has ceased the retort is raised to redness. When the operation is complete, a white powder remains in the retort, composed exclusively (?) of carbonate of soda and quick-lime, which, on treatment with water, reproduces caustic soda to serve for a new operation. The sulphate of ammonia thus obtained is coloured, but may be purified by re-crystallisation. If care is taken to operate on a homogeneous mixture of refuse and of alkalies, the whole of the organic nitrogen is recovered as ammonia. Conditions under which Super-Silicated CastMetal is Produced in Blast-Furnaces. Samson Jordan.-Managers of blast-furnaces, especially such as have had to produce cast-métal destined for the Bessemer process, have been called on to study the conditions under which the so-called "hot" cast-iron is produced, containing silicon to the extent of 1 to 2 per cent. Some have even manufactured extra silicated cast-iron containing 7 to 8 per cent. These latter pigs have a quite peculiar aspect. The colour of the recent fracture grows lighter as the proportion of silicon augments; the grain becomes larger, but flat, slightly rounded, without any projecting points or ridges. Its lustre recalls that of pure silicon. The finger in passing over the fracture experiences a sensation quite different from the touch peculiar to pigs rich in graphitic carbon. Thus, in the works which produce these extra silicated cast-irons, they are known under the name of "glazed pig." The following is the analysis of pig-iron of this nature manufactured at Towlaw, near Newcastle : The author has studied the production of extra silicated pig-iron at the works at Heerdt, near Dusseldorf. In consequence of an accident to the tubes, which led the air to six tuyeres of the furnace, it was necessary to work during eight days, blowing only through three with a feeble pressure. The temperature of the blast was extremely high, and the charge of minerals was much diminished. The fusible matters in this charge, and which were to form the slag, were in the following proportions:— 50 Oxygen 26.0 16 Silica .. Alumina Lime .. Protoxide of manganese.. 33 .. The conditions for obtaining extra silicated pig-metal are slow working at very high temperature and siliceous, and at the same time highly aluminous, charges. Great heat is required for the alloy of silicon and iron produced, which is more infusible than the common carboniferous cast-iron. The operation must be slow in order that the reduction of silica in presence of carbon and iron may be extensively effected. The proportion of lime must be reduced lest its affinity for silica might interfere with the reduction of the latter, and the alumina is increased to neutralise further the basic action of the lime. Memoirs on the Actions Produced by Molecular Attraction in Capillary Spaces.-M. Becquerel.-The conclusions arrived at in this memoir are these:1. Liquid layers adherent in capillary spaces, besides being capable of conducting electricity, have other properties which should be considered in studying electrochemical phenomena. 2. When certain saturated nonmetallic solutions are used, which produce double decompositions in their reciprocal reaction without capillary spaces with formation of insoluble precipitate, this precipitate is not formed in the interior of a capillary space where the walls are of glass (as in a cracked tube); there is a contest between the capillary affinities and the affinities between the two liquids which meet, and the latter are overcome. 3. Finely divided portions of matter, which is insoluble but constantly moist, behave like solid conducting substances on contact with an oxidisable metal, a number of electro-capillary currents are produced, which act like the ordinary voltaic currents. 4. Simple electrocapillary currents might, on account of their small intensity, be used as units for comparing electromotive forces in general; but such couples, when there is no metallic reduction, not being of constant current, this application is limited. 5. One may have an idea of the difference which exists Proportion of the oxygen of the silica to that of the bases between the capillary affinities exercised by the walls on 26'0 17.6 each of the two solutions, and the affinities uniting their constituent parts, from examining on which side precipitates are formed, within or without the crack. If within, this shows that the capillary affinity is less for the exterior than for the interior liquid. Heat Liberated in Reaction Between Alkalies and Water, Potash and Soda.-M. Berthelot.-A thermochemical study which scarcely permits of being summarised. Combinations Formed under the Influence of the Solvent Electric Discharge (Effluve) by Marsh-Gas and Carbonic Acid on the One Hand, and by Carbonic Oxide and Hydrogen on the Other.-MM. P. and A. Thenard.-In opposition to Sir B. Brodie's results, as given in our issue of 18th ult., these observers state that they found in the cases of both mixtures the contraction continuous; and that the product was in the form of a liquid condensed on the sides of the tube in drops, at first colourless but later becoming amber coloured, and |