[In. mod.L. catechu (also Ger. katechu, kateschu), app. ad. Malay kachu, (Tamil, Telugu, Canarese kācchu, kaycchu, kāshu) catechu (of acacia). The direct representatives of the latter are Pg. cacho, F. cachou; the exact history of the form catechu is obscure. See also the other names CACHOU, CASHOU, CATE2, CUTCH.]
A name given to several astringent substances, containing from 40 to 55 per cent. of tannin, which are obtained from the bark, wood or fruits of various Eastern trees and shrubs. They are used in medicine, and in tanning, calico printing, and dyeing.
The name was apparently first applied (in Europe) to the pale sort called also GAMBIER, obtained from the leaves and young shoots of Uncaria or Nauclea Gambir; this is the Catechu of Pharmacy (Syd. Soc. Lex.): when first brought to Europe in the 17th c. it was from its appearance believed to be an earth, and called Terra Japonica. The dark sort obtained from the wood of Acacia Catechu, is more commonly called CUTCH; of this Pegu Catechu is a good variety. (There is doubt whether the connection with Japan assumed in the name terra japonici is not purely imaginary, and owing to the Burmese name for Acacia Catechu, sha-pin, shabin, or shaben.)
[1654. Schröder, Pharmacop. Medico-chym. (Lyons), Catechu … Terra Japonica … genus terræ exoticæ. (Y.)
1679. Hagendornius (title), Tractatus Physico-Medicus de Catechu, seu Terra Japonica.
1683. Weekly Mem. Ingen., 157. A History of Catechu, or Terra Japonica.
1741. Compl. Fam.-Piece, I. i. 64. 2 Drams of choice Catechu or Japan Earth.
1805. C. Hatchett, in Phil. Trans., XCV. 288. Twenty grains of the common cutch or catechu being dissolved in nitric acid.
1875. Ure, Dict. Arts, I. 749. Gambir Catechu … imported under the name of Gambir, from Singapore and some of the neighbouring islands…. In the trade it is distinguished from the black catechu and cutch by the name of Terra Japonica.
b. Catechu Acacia, -tree; the Acacia Catechu.
1831. J. Davies, Manual Mat. Med., 450. Catechu tree.
1876. Harley, Mat. Med., 640. Catechu Acacia is a small tree, with straggling thorny branches, and hard, heavy, dark-red wood.
Hence Catechutannic acid, the tannic acid of catechu.
1863–75. Watts, Dict. Chem., Catechutannic acid softens when heated, and yields by distillation a yellow empyreumatic oil.
