Chemical Composition—The active constituent of stramonium seeds is the highly poisonous alkaloid Daturine, of which they afford only about ⅒ per cent., while the leaves and roots contain it in still smaller proportion.[1687] Daturine was discovered in 1833 by Geiger and Hesse, and regarded as identical with atropine by A. von Planta (1850), who found it to have the same composition as that alkaloid. The two bodies exhibit the same relations as to solubility and fusing point (88-90° C.); and they also agree in crystallizing easily. The experiments of Schroff (1852), tending to show that although daturine and atropine act in the same manner, the latter has twice the poisonous energy of the former, raised a further question as to the identity of the two alkaloids. Poehl (1876) also stated solutions of daturine to be levogyrate, those of atropine being devoid of rotatory power. From the observations of Erhard (1866), it would appear that the crystalline form of some of the salts of atropine and daturine is different. In stramonium seeds daturine appears to be combined with malic acid. The seeds yielded to Cloëz (1865) 2·9 per cent. of ash and 25 per cent. of fixed oil.
Uses—Stramonium seeds are prescribed in the form of extract or tincture as a sedative or narcotic.
SEMEN ET FOLIA DATURÆ ALBÆ.
Seeds and Leaves of the Indian or White-flowered Datura.
Botanical Origin—Datura alba Nees, a large, spreading annual plant, 2 to 6 feet high, bearing handsome, tubular, white flowers 5 to 6 inches long. The capsules are pendulous, of depressed globular form, rather broader than high, covered with sharp tubercles or thick short spines. They do not open by regular valves as in D. Stramonium, but split in different directions and break up into irregular fragments.
D. alba appears to be scarcely distinct from D. fastuosa L. Both are common in India, and are grown in gardens in the south of Europe.[1688]
History—The mediæval Arabian physicians were familiar with Datura alba, which is well described by Ibn Baytar[1689] under precisely the same Arabic name (Jouz-masal) that it bears at the present day; they were also fully aware of its poisonous properties.
Garcia de Orta[1690] (1563) observed the plant in India, and has narrated that its flowers or seeds are put into food to intoxicate persons it was designed to rob. It was also described by Christoval Acosta, who in his book on Indian drugs[1691] mentions two other varieties, one of them with yellow flowers, the seeds of either being very poisonous, and often administered with criminal intent, as well as for the cure of disease. Graham[1692] says of the plant that it possesses very strong narcotic properties, and has on several occasions been fatally used by Bombay thieves, who have administered it in order to deprive their victims of the power of resistance.
The seeds and fresh leaves have a place in the Pharmacopœia of India, 1868.
Description—The seeds of D. alba are very different in appearance from those of D. Stramonium, being of a light yellowish-brown, rather larger size, irregular in shape and somewhat shrivelled. Their form has been likened to the human ear; they are in fact obscurely triangular or flattened-pearshaped, the rounded end being thickened into a sinuous, convoluted, triple ridge, while the centre of the seed is somewhat depressed. The hilum runs from the pointed end nearly half-way up the length of the seed. The testa is marked with minute rugosities, but is not so distinctly pitted as in the seed of the D. Stramonium; it is also more developed, exhibiting in section large intercellular spaces to which are due its spongy texture. The seeds of the two species agree in internal structure as well as in taste; but those of D. alba do not give a fluorescent tincture.