Curcuma longa. Turmeric.
Nat. Ord. — Zingiberaceae. Sex. Syst. — Monandria Monogynia.
Description. — This plant has a perennial, tuberous, oblong, palmate root, of a deep-orange color internally. The leaves are radical, large, lanceolate, obliquely nerved, sheathing at their base, tapering at each end, smooth, of a uniform green color, and closely embracing each other. The scape rises from the center of the leaves, is short, thick, smooth, green, and constitutes a spike of numerous imbricated bracteal scales, between which the flowers successively make their appearance.
History. — Turmeric is a native of the East Indies and Cochin-China. The best is said to come from China. The dried root is in cylindrical or oblong pieces, about as thick as the finger, but not so long, tuberculated, somewhat contorted, externally yellowish-brown, internally deep orange-yellow, hard, compact, and having a waxy fracture. It has a peculiar odor and a warm, bitterish, and feebly aromatic taste ; and yields its properties to water or alcohol. The saliva is tinged yellow by it, when the root is chewed. It contains lignin, a fourth of its weight of yellowish starch, a small quantity of acrid, volatile oil, gum, a brown coloring matter, chloride of calcium, and an uncrystallizable yellow coloring matter named Cur cumin. This may be obtained by digesting the alcoholic extract of turmeric in ether, and evaporating the ethereal tincture. In this state it is mixed with a little volatile oil, from which it may be separated and obtained pure, by oxide of lead. It is brown in mass, yellow in powder, inodorous, tasteless, scarcely soluble in water, freely soluble in alcohol, ether, and the oils, fusible at 104°, and turned to a reddish-brown by the action of alkalies.
Properties and Uses. — Stimulant aromatic. Seldom used, except to color ointments and other pharmaceutic preparations. Turmeric Paper is used as a test of acids and alkalies, and is prepared by tinging white unsized paper with a tincture or decoction of Turmeric. The tincture may be made with one part of turmeric to six of proof spirit ; the decoction, with one part of the root to ten or twelve parts of water. Alkalies change turmeric to a reddish-brown. The concentrated mineral acids, boracic acid, and numerous salts, are said also to turn turmeric paper red, or reddish-brown — if this be so, its indications cannot be relied on with certainty.