290 Materia Medica. — Dorstenia Contrajerva. vart ii.

old, is a tea-spoonful, given in the morning for three daysand then followed by a brisk cathartic.

DORSTENIA. Spec. Plant. Willd. i. 682.Cl. 4. Ord. 1. Tetrandria Moaogynia. Nat. Ord. Scabridae, Linn.

Urtiea;, Juss.G. 244. Receptacle common, one-leafed, fleshy, in which solitary

seeds are nestled (or placed in sockets without attachment.)Spec. 5. D. Contrajerva, Contrayerva. Med. Bat. 2d edit. 705. 240.Officinal. CoNTRAjERViE radix, Lond. Dorstenije contra-

yeRvte radix, Ediii. Contrajerva Root.Syn. Contrajerva (F-), Giftvrarzel (G.), Contrajerva (/.), Contrahierba (S.')

This is a perennial plant, a native of Peru, Mexico, andsome of the West India islands. The root is fusiform, knotty,and branching, compact, furnished with many rough fibres; ex-ternally of a brown colour, and internally whitish. It sends upseveral leaves, which are about four inches in length and thesame m breadth ; of an irregular shape, but in general deeplylaciniated into five or seven obtuse parts; and placed on longradical footstalks, winged towards the leaves. The fructification,which is remarkable, and on radical stalks or scapes which riseabout four inches high, is a fleshy receptacle, shaped like ananimal placenta, about an inch long, and three-fourths of aninch broad, placed vertically; and containing on its upper sur-face very small, scarcely conspicuous flowers, situated closelytogether, immersed in the receptacle, and occupying the wholeof its disc. The capsule possesses an elastic power when ripe,by which the seeds are thrown out with considerable force.

Monardus is the first author who mentions this root, which,he says, is called Contrajerva' by the Spanish Indians, on ac-count of its alexipharmic qualities. Dr. Houston % however,asserted that the officinal contrajerva was the roots of two otherspecies of Dorstenia, the D. Hcmstonia andD. Drakena of Will-denow; but the British Colleges follow the authority of Lin-naeus. It is brought to this country from the West Indies,packed in bales, in pieces of about two inches long.

Qualities. — Contrajerva root has a peculiar, but not unplea-sant odour, and a bitterish, warm taste, leaving a pretty last-ing impression on the tongue. It preserves its qualities whendried; and in the state of powder. Both water and alcohol,assisted by heat, extract its virtues. The watery decoction isof a dark, brownish-red colour, and exceedingly mucilaginous..— The alcoholic tincture reddens litmus paper, is not alteredby a solution of-sulphate of iron, but is precipitated by water.Medical properties and uses. — This root is a stimulant sudo-rific and tonic. Huxham and Pringle first pointed it out as aremedy well suited to fevers of a typhoid type, and k is often em-

1 The Spanish, for the English word antidote, is contrahierba.» Phil. Tram. .No, 421. />. 195.