Acacia Catechu, Catechu; Catechu Nigrum (Br.) -- An extract prepared from the heart-wood, U.S.P. 1820-1890; India, Hindustan. Plant crooked, shrubby tree, 4.5-12 M. (15-40 degrees) high, 15-45 Cm. (6-18') thick, bark brown, wood whitish and reddish, leaves paripinnate, prinnae in 10-20 pairs, with a pair of hooked, brown prickles at each base, leaflets 20-30 pairs in each in each pinna, flowers yellow, fruit, pod (loment), brown, flat, 5-12.5 Cm. (2-5') long, seed 3-10 brown, shining; extract (catechu) in irregular masses, dark brown, brittle, porous, fracture conchoidal, little glossy, inodorous, taste sweetish, astringent. It is prepared by removing bark and sapwood, and boiling in water, for about 12 hours, the reddish-black heart-wood, cut in chips, straining, evaporating, stirring frequently and vigorously to improve the product - over-boiling being injurious, as it converts catechin into catechu-tannic acid; when of syrupy consistency it is cooled somewhat with cow-dung ashes; by morning it is hard, brittle, when it is broken up into suitable pieces for market; contains catechu-tannic acid 35 p.c., catechin 13-34 p.c., quercetin, gum, extractive. There are several varieties: 1, Plano-convex (Cake); 2, Pegu; 3, Quadrangular (Cake), Bengal; 4, Ball, Bombay. Adulterations: Largely with leaves, mats, cloths, sticks, sand, dried blood, ashes, clay, starch, ferrous carbonate, sometimes to 65 p.c.; artificial variety made from roasted mahogany, walnut, etc. Astringent, tonic, similar to tannic acid - much more harsh than gambir, owing to which it is used chiefly for tanning, arts, etc.; diarrhea, leucorrhea, gonorrhea, chronic sore throat, relaxed uvula, spongy gums (mouth wash), hemorrhages, bronchitis. Dose, gr. 5-30 (.3-2 Gm); compound tincture, 10 p.c. (Diluted alcohol) dose, 3 ss-2 (2-8 cc.); fluidextract; infusion. A. Arabica (vera) and A.Decurrens, bark (Acacia Cortex - Br.) Rusty brown blackish, striated, spines and fruit long; contains tannin, mucilage: Decoctum, 6 p.c.; A. Gummif'era, A. Ehrenbergia'na, A. Adanso'nii, A. Tor'tilis, A. Fis'tula, and several others give valuable gums. A. Su'ma differs from A. Catechu only in its white bark, more leaflets, shorter corolla, and stronger spines; S. India, E. Africa (forests), S. America once furnished most of the commercial catechu, and still some; the bark used in tanning. A. Arabica, Babul Bark, India; furnishes good extract; the fruit contains tannin 22 p.c.