Acacia catechu. Catechu. (Cutch. Gambeer. Terra Japonica.)
Nat. Ord. — Fabaceae, or Leguminosae. Tribe. — Mimoseae. Sex. Syst. — Polygamia Monoecia.
Extract of the Wood.
Description. — The Acacia Catechu is a small tree, seldom more than twelve feet high, and with a trunk one foot in diameter. The bark of the tree is thick, scabrous, ferruginous, red within, very astringent and somewhat bitter. The branches are spreading and irregular, and when young, pubescent ; the older ones have many stipular prickles, in pairs and recurved. The leaves are alternate, and consist of ten to thirty pairs of pinnae about two inches long, each having many small, linear leaflets, covered with short hairs, and of a pale-green color. At the base of each pair of pinnae is a small gland upon the common petiole, and attached to the stem at the base of each leaf, are two short, recurved spines. The /lowers are numerous, axillary, in slender cylindrical spikes, about four or five inches long, and of a pale-yellow color. The calyx tubular, hairy, and five-toothed. The corolla is composed of five petals, united into a tube at the base, and is longer than the calyx. Stamens numerous, distinct, with roundish anthers. The ovary is green, oval, glabrous, supporting a slender style, and terminated by a simple stigma. The legume is lanceolate, flat, straight, smooth, and brown, with an undulated thin margin, containing six or eight roundish, flattened seeds, which emit a nauseous odor when chewed.
History. — This species of Acacia is a native of the East Indies, growing abundantly in Hindostan and in the Burman empire. The officinal catechu is prepared by boiling the leaves or wood in water, then evaporating to the proper consistence, and pouring into quadrangular earthen molds. Catechu is likewise obtained from the Areca Catechu and Uncaria Gambir. There are several kinds of it met with in commerce, but the best is that which possesses the most astringency, and which can be determined by the taste.
Catechu varies in its color and appearance, being from pale to a dark-brown, in square, round, and irregular pieces, friable, specific gravity 1.2 to 1.3, inodorous, astringent, and succeeded by an agreeable sweet taste. That which is preferred is of a dark color, easily broken into small angular fragments, with a smooth, glossy surface, bearing some resemblance to Kino. It is soluble in hot water, which deposits a reddish matter on cooling. Cold water partially dissolves it. Alcohol or proof spirit dissolves it readily. It contains tannin, extractive, and mucilage. Ether dissolves its tannin and catechuic acids. The dark-colored catechu is the most astringent.
It is incompatible with solutions of the pure earths, with sulphuric acid or muriatic acids, salts of alumina, lead, copper, and of the sesquioxide of iron, also with gelatin, opium, cinchona, and those salts of the vegetable alkaloids, which form insoluble salts with tannin.
Properties and Uses. — Catechu is a pure and powerful astringent, and slightly tonic. It is used for arresting mucous discharges when excessive, for removing relaxation or congestion of mucous membranes, and for checking hemorrhages. In chronic diarrhea, chronic catarrh, colliquative diarrhea, and chronic dysentery, it has proved beneficial especially when combined with opium. As a local application it is a valuable agent for removing cynanche tonsillaris, aphthous ulcerations of the mouth, elongation of the uvula, and relaxation and congestion of the mucous membrane of the fauces, especially of the kind to which public singers are subject ; it is also useful in congestion, tenderness and sponginess of the gums, particularly when the result of mercurial ptyalism. The tincture of catechu is often useful in fissure of the nipples, when applied twice a day with a fine hair pencil. Catechu is likewise beneficial as a topical application to ulcers of a phagedenic character, and to indolent ulcers. An infusion of catechu may be used as an injection in obstinate gonorrhea, gleet, and leucorrhea ; and thrown up the nostrils is beneficial in epistaxis. The dose of powdered catechu is from ten to thirty grains, frequently repeated, and is best given with sugar, gum arabic, and water ; dose of the tincture from one drachm to half a fluidounce.