686

ELEMENTS OF MATERIA MEDICA.

Curcumin: Yellow Colouring Matter.— Is obtained, mixed with some volatile oil * nchloride of calcium, by digesting- the alcoholic extract of turmeric in ether, and evapO'rating the etherial tincture to dryness. In the mass, curcumin is brownish-yell 0 ')’but when powdered it becomes full yellow. It is tasteless, odourless, almost insolubl®in water, but readily soluble in alcohol and ether. These properties shew that it is °a resinous nature. The alkalies colour it reddish-brown, and readily dissolve it. I®alcoholic solution, evaporated with boracic acid, becomes red. Hydrochloric acid alsoreddens it. The alcoholic solution of curcumin produces coloured precipitates wit"several salts, as acetate of lead and nitrate of silver.

Characteristics. —The alkalies change an infusion of turmeric, ° rturmeric paper, to reddish-brown. A similar alteration of colour occurswhen turmeric paper is exposed to the vapour of hydrochloric acid g 3 ^or is touched with oil of vitriol. If to tincture of turmeric boracic ad°be added, and the mixture be evaporated to dryness, an orange-r eresidue is obtained, whereas, without the acid, the residue is yell 0 ")Sulphate of copper causes a yellowish precipitate with an infusion 0turmeric. A similar effect is produced by sesquicliloride of iron.

Physiological Effects. —Are those of a mild aromatic, vide p-The colouring matter becomes absorbed, and communicates a yell 0 "'tinge to the urine (Lewis, Mat. Med.; andReiger, quoted by Murray*App. Med. vol. v. p. 78). According to Mr. Gibson [Mem. of the Ld-and Phil. Soc. of Manchester,\ ol. i. Sec. Ser. p. 148), the colouring matt® 1 -of turmeric is somewhat changed by the digestive organs; for the sto° lsof animals fed with this root were green, whilst either logwood or madd° rexhibited its respective hues after passing through the intestines.

Uses. —Employed as a condiment, colouring ingredient, and test. ,.is a constituent of the well-known curry powder and curry paste , and 0many other articles of Indian cookery. Formerly it had some reputati 0 "in hepatic and other visceral diseases, and especially in jaundice.test it is used to detect the presence of free alkalies, which change 1yellow colour to reddish-brown. But some acids, and several sal^*produce the same effect on it. Turmeric paper is prepared with whd e *bibulous, or unsized paper, which is to be brushed over with, or soak 0in, a decoction of turmeric (prepared by boiling one ounce of f 9coarsely-powdered rhizome in ten or twelve ounces of water, strain 111 'Jthrough a cloth, and allowing the fluid to settle for a minute or two), aIlt ,drying in the air, the access of alkaline and acid fumes being prevent 0(Faraday, Chem. Manipulation ).

Curcu'ma angustifo'lia, Roxburgh.— The narrow-leaved Turmeric.

(Fecula tuberis. East Indian Arrow-root, Offic.)

History. —This plant was found by H. T. Colebrook, Esq. 1)1 ^forests extending from the banks of the Sona to Nagpore , and was .him introduced into the Botanic Garden at Calcutta (Roxburgh, * 'Indica ).

Botany. Gen. Char. —Vide Curcuma longa. ,

Si>. Char. — Bulb oblong, with pale, oblong, pendulous tubers on )Leaves stalked, narrow-lanceolate. Flowers longer than the bracts.

Hab .—East Indies: from the banks of the Sona to Nagpore . *■ .fecula obtained from its tubers is sold in the markets of Benares, an