the same time much moved. The gastric juice thus obtained was almost perfectly clear, scarcely opalescent. The stomach of a dog of the size of a poodle contained from fifteen to forty grms. of a liquid, which flowed out spontaneously; that of a large pointer, from thirty to ninety grms. The fresh gastric juice was poured into a shallow broad flask, the mouth of which was closed by a cork, and through this, a glass tube, bent four times at a right angle, was passed; the latter was covered with nitrate of silver on its inner side. The apparatus was placed under the airpump with dry hydrate of potash, and exhaustion then applied. When the gastric juice had been evaporated until it was of a syrupy consistence, vapors of muriatic acid were evolved somewhat suddenly, so that the chlorid of silver formed could be determined qualitatively and quantitatively. Treated in this manner, a gastric juice which was but slightly opalescent for instance, yielded 1-808 per cent. of solid residue, 0-125 per cent. muriatic acid, and 98-067 per cent. of water. This muriatic acid is formed by the decomposing action of the lactic acid at a certain degree of concentration, even in the cold, upon many chlorids, especially those of calcium and magnesium, but not the chlorids of potassium and sodium. To prove the presence of the lactic acid itself with certainty, the gastric juice was concentrated in vacuo to one-twelfth its volume, the residue mixed with alcohol of 0.85 spec. grav., the spirituous solutions from several stomachs evaporated to the consistence of a syrup, and the residue exhausted with absolute alcohol. The residue of this was exhausted with ether, and the ethereal extract mixed with water to remove the fat, and filtered. On further concentration, more drops of oil separated from the filtrate; moreover, the fluid about to be tested still contained muriate of ammonia. The liquid was partly saturated with lime, partly with magnesia, and the salts formed were purified by several recrystallizations from alcohol and water. magnesian salt, dried at 266° F., and then incinerated, gave 16·666 per cent. of magnesia, 61.906 per cent. lactic acid, and 21.428 per cent. water; the formula MgO, La+3HO requires 16.085 per cent. magnesia, 62-936 per cent. lactic acid, and 20-979 per cent. water. some other experiments, fasting dogs were fed from twenty to forty-five minutes before death with horse-flesh containing but little fat. The fluid which flowed spontaneously from the stomach, when filtered, left 5-602 per cent. of residue, and thus contained nutritive matters already in solution, which were detected by the copious precipitate produced by alcohol, or the formation of yellowish-brown films on evaporation. The gastric fluid thus obtained yielded no muriatic acid under the airpump. From this fluid a magnesian salt was also obtained. I. gave 16-666 per cent. of magnesia, 62-122 La, and 21-212 HO; II., which was obtained by exhausting the contents of the stomach with water, gave 15.966 per cent. MgO, 62.026 La, and 21·008 per cent. of HO. 6. Equivalent number of Titanium, (L'Institut, March 10, 1847.)The equivalent of titanium has been determined from the bichlorid of titanium by M. Isidore Pierre, Professor at Bordeaux. He obtained, in a series of five experiments, the numbers 314-76, 314-37, 314-94, 311-84, 309-88; in a second series, 313-41, 311-30, and in a third 311-58, 309-41. Operating with the greatest care, some small pro The In portion of the chlorid is supposed to decompose during the experiment, through the humidity of the air; and in this way M. Pierre accounts for the variation in the above results. Believing that the first three results are most correct, he adopts the number 314-69 (or on the hydrogen scale, 25-13) for the equivalent. 7. On the compounds of Iron with Carbon; by M. KARSTEN, (Bericht Berlin Akad., Nov. 5, 1846; Chem. Gaz., March, 1847.)-The determination of the amount of carbon in the different kinds of bar iron, steel and pig iron, are still variable and uncertain, partly owing to the estimation of the amount of carbon being very tedious if not difficult, and partly because the limits between bar iron and steel, as well as between steel and pig iron, are wholly undetermined, and are merely assumed conventionally from certain physical properties of the product. Combinations in definite proportions between iron and carbon are not to be met with in the carburets of iron; for the union of these two substances takes place in indefinite proportions, uninterruptedly, from 0 to the maximum amount of carbon, which is about 5.93 per cent. The classification of the carburets of iron in three divisions, bar iron, steel, and pig iron, is consequently not necessary, i. e., not required, by the combining proportions, but wholly arbitrary. To determine the amount of carbon, the best methods of separating the carbon from iron were employed; but in order to ascertain the degree of trust-worthiness belonging to each, white pig iron, with a bright metallic surface, smelted with charcoal from sparry iron ore at the Sayner works near Bendorf on the Rhine, was submitted to experiment. This pig iron contains no uncombined carbon (graphite), or at least but mere traces; and the amount of combined carbon approaches closely to the maximum amount which iron is capable of taking up. The amount of carbon of this pig iron was found, by different methods of analysis, as follows: By elementary analysis with oxyd of copper, the carbon be- Per cent. 4.2835 5.7046 As all bar iron contains more or less carbon, some decision should be made as to the limits up to which it should be called bar iron, and below which steel. If the limits are fixed by calling that bar iron steel which becomes so hard by cooling in water after having been hardened that it gives sparks with quartz, this effect occurs only when the iron has taken up 0.5 of carbon. Iron which is perfectly free from foreign ingredients may even combine with 0.65 per cent. of carbon before attaining the above degree of hardness. The purer the iron and the less foreign substances (silicium, sulphur, phosphorus) it contains, the greater amount of carbon will it require in order to become much harder after the process of hardening than previous to it. Iron which contains 0.5 to 0.65 per cent. of carbon is very soft steel; the hardness and tenacity of the steel increase with the amount of the carbon. From 14 to 15 per cent. appears to be the limit at which steel exhibits after hardening the greatest hardness with the greatest tenacity; with more carbon the hardness increases, but the malleabili. ty and tenacity of the steel are diminished; when it amounts to 1.75 per cent. the steel is very slightly malleable; with 19 it can scarcely be welded red-hot, and with 2 per cent. it breaks to pieces under the hammer. In this state the steel might already be called pig iron; but it may be beaten in the cold, and does not possess the property of separating a portion of its carbon in the form of graphite when allowed to cool very slowly after fusion. This occurs only when the carbon amounts to 2.25 or 2-3 per cent. If, therefore, a line of demarcation were to be drawn between steel and pig iron, which should be founded upon the combining proportions, 2-3 would characterize this limit. The more carbon the pig iron takes up, from that minimum to the maximum of 5.93 per cent., the lighter does the color become, and the greater the hardness of the white variety, which is analogous to hardened steel. The gray variety, with an equal amount of carbon, which is analogous to unhardened steel, will be softer, that is, will separate the more graphite on solidification, the slower the cooling. The gray pig iron, which contains the same amount of carbon as the corresponding white kind, may consequently be sometimes a mixture of white pig iron with graphite, sometimes of soft steel or of hard bar iron and graphite, according as the solidification resulted more or less slowly, and the solidified mixture retained more or less carbon in the combined state. When the solidification is sudden, gray iron is scarcely formed, because the entire amount of carbon remains chemically combined with the iron, and is not separated as graphite. In preparing cast steel, the process is purely empirical, the eye of the workmen being the weight and balance in determining the amount of carbon in the material to be employed. To manufacture cast steel with certain properties, those materials must be selected in which the amount of carbon is known, and which, by being fused together in accurately calculated proportions, produce a cast steel containing that amount of carbon which corresponds with the properties required of the cast steel to be prepared. 8. Note on the Action of a Solution of Caustic Soda upon a Stoneware Jur; by Mr. TRENHAM REEKS, (Chem. Gaz., April, 1847.)— The author's attention was drawn to this subject from the presence of a large quantity of alumina in the analyses of some bronzes and iron ores. On examining the reagents employed, it was found that it origi nated in the soda, which had been kept for some time in a stoneware jar, the alumina of which had been dissolved out by the soda, and a thick coating of silica left closely adhering to its surface. SECOND SERIES, Vol. IV, No. 10.-July, 1847.. 14 9. On the Detection of Cotton in Linen; by G. C. KINDT, (Liebig's Annalen, Feb., 1846; Chem. Gaz., April, 1847.)-This subject has frequently engaged the attention of commercial and scientific men; many experiments have been made in order to detect cotton thread in linen; many processes have been recommended, but none have hitherto proved satisfactory. I was therefore much surprised when a stranger, a few weeks ago, showed me a sample of linen from the onehalf of which all the cotton filaments had been eaten away. He had obtained it in Hamburg, and asked me whether I could give him a process for effecting this purpose. Now since, as far as I am aware, nothing has been published on this subject, and it is of very general interest, I consider it a duty to communicate the results of my experi ments. I had already observed, in experimenting with explosive cotton, flax, &c., that these two substances behave somewhat differently towards concentrated acids; and although it has long been known that strong sulphuric acid converts all vegetable fibre into gum, and when the action is continued for a longer period, into sugar, I found that cot. ton was metamorphosed much more rapidly by the sulphuric acid than flax. It is therefore by means of concentrated sulphuric acid that cotton may be removed from linen when mixed with it; and this object may be effected by the following process: The sample to be examined must be freed as perfectly as possible from all dressing by repeated washing with hot rain or river-water, boiling for some length of time, and subsequent rinsing in the same water; and I may expressly observe, that its entire removal is requisite for the experiment to succeed. When it has been well dried, the sample is dipped for about half its length into common oil of vitriol, and kept there for about half a minute or to two minutes, according to the strength of the tissue. The immersed portion is seen to become transparent. It is now placed in water which dissolves out the gummy mass produced from the cotton; this solution may be expedited by a gentle rubbing with the fingers; but since it is not easy to remove the whole of the acid by repeated washing in fresh water, it is advisable to immerse the sample for a few instants in spirits of hartshorn, (purified potash or soda has the same effect,) and then to wash it again with water. After it has been freed from the greater portion of the moisture by gentle pressure between blotting-paper, it is dried. If it contained cotton, the cotton threads are found to be wanting in that portion which had been immersed in the acid; and by counting the threads of the two portions of the sample, its quantity may be very readily estimated. If the sample has been allowed to remain too long in sulphuric acid, the linen threads likewise become brittle, or even eaten away; if it were not left a sufficient time in it, only a portion of the cotton threads have been removed; to make this sample useful, it must be washed, dried, and the immersion in the acid repeated. When the tissue under examination consists of pure linen, the portion immersed in the acid likewise becomes transparent, but more slowly and in a uniform manner, whereas in the mixed textures the cotton threads are already per fectly transparent, while the linen threads still continue white and opake. The sulphuric acid acts upon the flax thread of pure linen, and the sample is even somewhat transparent after drying as far as the acid acted upon it, but all the threads in the sample can be seen in their whole course. Cotton stuffs containing no linen dissolve quickly and entirely in the acid; or if left but one instant in it, become so brittle and gummy that no one will fail to recognize it as cotton when treated in the above manner. 10. Nitrification and the Fertilization of Soils; by F. KUHLMANN, (Comptes Rendus, Nov., 1846.)-The researches of this author published in 1838 are well known. By these he demonstrated that all the gaseous or vaporizable compounds of nitrogen, were converted into ammonia by the hydrogen and hydrogenous gases in contact with heated spongy platinum, and that on the other hand, all these compounds were converted into nitric acid or peroxyd of nitrogen, by oxygen or oxydating gases. Upon this foundation the following view is based. Animal substances exercise a beneficial effect only when carbonate of ammonia is disengaged by their decomposition; in like manner, according to Kuhlmann, the nitrates are effectual as manures, only when the nitric acid has been converted into ammonia by the deoxydizing influence of putrid fermentation. Various recent experiments are brought to prove that this opinion is correct, and that similar conversions to those observed in gases take place in liquids. Nitre thrown into a mixture of zinc or iron and sulphuric or better dilute hydrochloric acid, retards or stops the disengagement of hydrogen until the whole of the nitric acid is converted into ammonia. Nascent sulphuretted hydrogen produces the same effect, with deposition of sulphur. A current of sulphuretted hydrogen passed through a solution of chlorid of antimony and a nitrate, in like manner transforms the nitric acid into ammonia. The author entertains the opinion that the ammonia of the atmosphere or of manures, is converted at the surface of the soil into nitrates, and that this process of nitrification prevents the waste of ammonia; these nitrates are in their turn deoxydized by fermentation and afford ammonia to the plant. The peroxyd of manganese is proposed as an agent for the perpetual transference of the oxygen of the air to ammonia, producing its conversion into nitric acid; MnO, being deoxydized by the ammonia and the resulting MnO being converted by the air into MnO4, which in its turn is deoxydated. M. Kuhlmann considers it possible, in case of a deficient supply of nitre in Europe, to convert ainmonia into nitric acid economicallyand on the contrary with the nitrates from India and Chili to form ammonia, by turning to account the hydrogen or sulphuretted hydrogen, which is lost in many operations and is even a source of injury to health. He also proposes a new process for determining nitric acid, based upon the conversion of nitrates into ammonia, under the influence of nascent hydrogen. G. C. S. 11. Anhydrous Alcohol; by M. CASORIA, (Phil. Mag., Nov., 1846, from Jour. de Chim. Med.)-Perfectly dry sulphate of copper is proposed as a means of rendering alcohol anhydrous, and as a test for the |