Gleanings from the German Journals.
By JOHN M. MAISCH.
The Oil of Grapeseed has been analyzed by A. Fitz. It consists of the glycerin compound of palmitic, stearic, erucic and another acid or acids, yielding soft semiliquid salts with barium and lead. The two first named acids are present in very small proportion; erucic acid constitutes about one-half of the acid mixture. Grapeseed contain 15 to 18 per cent. of fixed oil, and 5 to 6 per cent. tannin; the latter in connection with isinglass is an excellent material for the clarification of the finer wines, for which the ordinary tannin cannot be used.—Ber. d. d. Chem. Gesellsch. 1871, 442-446.
An Analysis of a Himalaya Tea has been made by Ph. Zöller. The tea had been presented to Prof. Liebig, and consisted of very young leaves. It contained 4.95 per cent. water and 5.63 ashes, of which latter 39.22 per cent. was potassa, 14.55 phosphoric acid, 4.38 oxide of iron, 1.03 oxide of manganium, and only 4.24 lime. The air-dry tea yielded ammonia equivalent to 5.38 per cent. nitrogen, and besides 4.94 theina a small quantity of a crystalline compound of the behavior of theobromina. By infusion with boiling water, 36.26 per cent. dry extract was obtained, containing nearly the entire amount of potassa, very little lime, almost two-thirds of the nitrogen, nearly one-half of the phosphoric acid, and one-third of the iron and manganese. The author shows that exhausted tea leaves, which are often used for adulterating tea, can be readily recognized from the amount and the composition of the ashes, and argues that in old tea leaves the relative proportion of the inorganic constituents is altered so that the potassa and phosphoric acid decrease while lime is increased in quantity.—Ann. d. Chem. und Pharm. 1871, May, 180-193.
Tinctura Rhei Aquosa.—Dr. Th. Rieckher recommends the following process for obtaining a permanent aqueous tincture of rhubarb, the processes of the various pharmacopoeias used in Germany, yielding preparations which in a short time separate deposits: 2 parts of cut rhubarb are macerated for 24 hours with a sufficient quantity of water, then introduced into a glass percolator and displaced with water until 48 parts of infusion have been obtained. This is evaporated in a porcelain capsule, by means of a steam-bath, to 13 parts, when 1 part crystallized carbonate of soda and two parts of cinnamon water are added. After several days the tincture is passed through a felt filter, and now has the specific gravity 1.0400.—N. Jahrb. Ph. 1871, March, 142-146.
Attar of Rose is, according to Grund, of Breslau, often adulterated with alcohol, which raises the congealing point of the attar. The adulteration is detected by agitation with lukewarm water in the usual manner.—Ibid., 165.
Castor Oil.—O. Popp has observed that castor oil turns polarized light to the right, and differs in this respect from all other fats. He also found all the commercial castor oil to contain nitrogen, and finds in these facts supports of his previously expressed opinion, that the purgative properties of this oil are due to a nitrogenated body, probably an alkaloid.—Archiv d. Pharm. 1871, March, 233, 234.