Scientific Serials

Abstract

Journal of the Chemical Society, April 1870. This number contains a “Note on some Reactions of Alcohols,” by Mr. E. T. Chapman. The author finds that on distilling with caustic soda a mixture of the rotating and non-rotating amylic alcohols to dryness, the distillate contains a larger proportion of the rotating alcohol than the original liquid; and, on adding water to the residue of sodic amylate and distilling the alcohol which passes over with the water is almost free from the rotating variety. A repetition of the process renders it quite pure. He also finds that repeated treatment of the rotating alcohol by caustic soda converts it into the non-rotating. On treating amylic alcohol to which about 2 ¼ per cent, of water was added with a quantity of sodium just sufficient to decompose the water, and distilling, water first passed over, followed by amylic alcohol; sodic amylate almost free from caustic soda remaining in the retort; showing that the sodium replaces the hydrogen of the alcohol in preference to that of the water. Again, on distilling a solution of caustic soda in amylic alcohol, water passed over with the alcohol, the residue being sodic amylate.—“Note on the Organic Matter contained in Air,” by Mr. E. T. Chapman. Several methods were tried for collecting the organic matter from the air before estimating its quantity. Passing the air through water in a Liebig's potash apparatus, or even in a tube with twenty-five bulbs, did not fix the whole of the organic matters. Cotton wool and gun-cotton failed on account of their invariably containing nitrogenous bodies, which vitiated the results; the condensation of steam in the air and washing with fine spray were better, but not satisfactory. Filtering the air through asbestos paper succeeded very well, but the asbestos was difficult to manage. The process finally adopted was to pass 100 litres of air through a quantity of finely powdered and moistened pumice stone, placed on a piece of wire gauze, fixed on the wide end of a funnel; distilling the pumice with dilute potassic hydrate and potassic permanganate, and determining the quantity of ammonia in the distillate by Nessler's test. In crowded rooms and near an untrapped sink, the air was found to contain organic bases as well as ammonia. 100 litres of air from crowded rooms contained quantities of nitrogenous substances, producing from 0˙02 to 0˙35 milligrammes of ammonia.—Then follows a lecture by Dr. Gladstone on “Refraction equivalents,” which has already been noticed in these columns. The number concludes with a long paper by Dr. Thudichum on “Kryptophanic acid, the normal free acid of Human Urine.” From the analysis of the salts it appears to be a dibasic acid of the formula C₅ H₉ N O₅ or a tetrabasic acid containing C₁₀ H₁₈ N₂ O₁₀