NUX VOMICA, a poisonous drug, consisting of the seed of Strychnos Nux-Vomica, a tree belonging to the natural order Loganiaceae, indigenous to most parts of India, and found also in Burma, Siam, Cochin China and northern. Australia. The tree is of moderate size, with a short, thick, often crooked, stem, and ovate entire leaves, marked with three to five 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 I to 5 seeds are vertically embedded. The seed is disk-shaped, rather less than I in.. in diameter, and about 3/4 in. in thickness, slightly depressed towards the centre, and in some varieties furnished with an. acute keel-like ridge at the margin. The external surface of the seed is of a greyish-green color 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 halves by a fissure, in which lies the embryo. The latter is about 1a~ in. long, and has a pair of heart-shaped membranous cotyledons.