Strychnine, a poisonous drug, is named from a genus of tropical trees and shrubs of the order Loganiaceæ. The most notable species is the Strychnos Nux Vomica, so called from the name Nux Vomica given to its seeds, the source of strychnine. The tree and its seeds are described as NUX VOMICA. From various species of Strychnos are obtained the Clearing Nut (q.v.), the Curari (q.v.) poison, and Ignatius' Beans (q.v.); while one kind of Upas poison (Upas tieute) is made from a species of Strychnos.
Strychnine, , is an alkaloid occurring in crystals, has an intensely bitter taste, is colourless and inodorous, scarcely soluble in water, but easily soluble in boiling rectified spirit, in ether, and in chloroform. Pure sulphuric acid forms with it a colourless solution, which, on the addition of bichromate of potash, acquires an intensely violet hue, speedily passing through red to yellow. In nitric acid it ought, if pure, to form a colourless solution; if the solution is reddish it is a sign that brucine is also present. Strychnine combines with numerous acids, and forms well-marked salts, which give the same reactions as the base itself. Nux vomica seeds contain about '2 to '5 per cent. of it.—Brucine is the subject of a separate article.
Strychnine and brucine occur not only in nux vomica, but in the seeds of Strychnos amara (St Ignatius' beans) and in the seeds and other parts of several plants of the genus Strychnos. Nux vomica and its alkaloids are very poisonous to all kinds of animals. It is believed, however, that the bird called Buceros rhinoceros eats the nuts with impunity; and a peculiar kind of Acarus lives and thrives in the extract of the nuts. In small doses (th to th grain) it is largely used in medicine as a stimulant, as a tonic, and as a bitter. The officinal preparations are made from nux vomica and from strychnine. In poisoning with strychnine the symptoms depend on excessive stimulation of the spinal cord, and when fully developed consist in rigid tetanic convulsions. These are preceded by muscular twitchings, cramps, and jerking movements. Each spasm lasts one or two minutes, and is followed by a short remission, during which the person lies completely exhausted, but able to converse and swallow. The slightest touch, a noise, or even a draught of air will bring on a spasm. The mind generally remains quite clear. Death takes place within two hours from exhaustion, or from suffocation produced by the impossibility of breathing during the spasms. Death may occur in a few minutes, however; a quarter of a grain is the smallest fatal dose of strychnine recorded, but patients have survived much larger amounts.
The treatment, after emptying the stomach, consists in keeping the patient as quiet as possible, and in administering substances which will depress the spinal cord, and thereby allay the tetanic spasms. Chloral hydrate and bromide of potassium by the mouth or rectum have been found useful in this respect. But putting the patient deeply under the influence of chloroform is probably the most efficacious mode of treatment.