NUX VOMICA, a poisonous drug, consisting of the seed of Strychnos Nux-Vomica, L., a tree indigenous to most parts of India, and found also in Burmah, Siam, Cochin China, and northern Australia. The tree, which belongs to the natural order Loganiaceae, is of moderate size, with a short, thick, often crooked stem, and ovate entire leaves, marked with 5 or 6 or 7 veins radiating from the base of the leaf. The flowers are small, greenish-white, and tubular, and are arranged in terminal corymbs. The fruit is of the size of a small orange, and has a thin hard shell, enclosing a bitter, gelatinous, white pulp, in which from 1 to 5 seeds are vertically embedded. The seed is disk-shaped, rather less than 1 inch in diameter, and about I inch in thickness, slightly depressed towards the centre, and in some varieties furnished with an acute keel-like ridge at the margin. This is particularly the case with the seeds imported from Bombay and collected in that province. Those imported from Madras and Cochin China have usually a rounded margin (Pharm. Journ. [3], xii. p.
1053). The acute margin is considered in commerce indicative of superior quality, seeds so characterized yielding the largest quantity of the active principles. The external surface of the seed is of a greyish-green colour and satiny appearance, due to a coating of appressed silky hairs. The interior of the seed consists chiefly of horny albumen, which is easily divided along its outer edge into two halves by a fissure, in which lies the embryo. The latter is about three-tenths of an inch long, having a pair of heart-shaped membranous cotyledons....
The drug owes its poisonous property chiefly to the alkaloids strychnia and brucia, the mixed alkaloids found in the seed being in the proportion of about 1 per cent, of the former to 2 per cent, of the latter. These alkaloids occur in the seeds in combination with a probably complex body which has been named strychnic or igasuric acid. Brucia is distinguished from strychnia by giving a red colour when moistened with strong nitric acid, and by being soluble in 150 parts of boiling water, while strychnia requires 2500 parts for its solution. It is remarkable that although the pulp contains strychnia it is not poisonous to birds, being eaten by the hornbill, Buceros malabaricus, and other species. Parasitic plants of the natural order Loranthaceae, when growing on Strychnos Nux-Vomica, acquire the poisonous properties of the latter.
Nux Vomica seeds are imported into Great Britain from Bombay, Madras, and Cochin China to the average extent of about 200 tons per annum, valued at £1600.
