[508] W. R. Dunstan and A. E. Chaston. Pharm. Journ. Trans. (3), xx. 461-464.
[509] See Ber. der deutsch. Chem. Gesell., 13, 1549 to 1554. By boiling hyoscine hydrochloride with animal charcoal, and then precipitating with auric chloride, a good crystalline compound, melting at 198°, can be obtained.
Hyoscyamine (C17H23NO3), as separated in the course of analysis, is a resinoid, sticky, amorphous mass, difficult to dry, and possessing a tobacco-like odour. It can, however, be obtained in well-marked odourless crystals, which melt at 108°-109°, a portion subliming unchanged. It liquefies under boiling water without crystallisation. According to Thorey,[510] hyoscyamine crystallises out of chloroform in rhombic tables, and out of benzene in fine needles; but out of ether or amyl alcohol it remains amorphous. When perfectly pure, it dissolves with difficulty in cold, but more readily in hot, water; if impure, it is hygroscopic, and its solubility is much increased. In any case, it dissolves easily in alcohol, ether, chloroform, amyl alcohol, benzene, and dilute acids. Hyoscyamine neutralises acids fully, and forms crystallisable salts, which assume for the most part the form of needles. It is isomeric with atropine, and is converted into atropine by heating to 110°, or warming with alcoholic potash. The gold salt melts at 159°, and does not melt in boiling water like the atropine gold salt.
[510] Pharm. Zeitschr. f. Russl., 1869.
§ 457. Pharmaceutical and other Preparations of Henbane.—The leaves are alone officinal in the European pharmacopœias; but the seeds and the root, or the flowers, may be met with occasionally, especially among herbalists. The table[511] ([p. 382]) will give an idea of the alkaloidal content of the different parts of the plant.
[511] This table, taken from Dragendorff’s Chemische Werthbestimmung einiger starkwirkenden Droguen, embodies the researches of Thorey.