An extract prepared from the wood of Acacia Catechu. Pegu.

Characters. - In dark brown, irregular masses, containing fragments of leaves, brittle, somewhat porous and glossy when freshly broken; soluble in alcohol and partly soluble in water. It is nearly inodorous, and has a strongly astringent and sweetish taste.

It was formerly officinal in the B.P. It is sometimes called black catechu to distinguish it from the pale catechu got from Uncaria Gambier.

Composition and Reactions. - It contains a form of tannic acid called catechu-tannic acid. This differs from other forms of tannic acid in not being a glucoside. It gives a greenish-black colour with iron, and precipitates gelatine but not tartar emetic.

Preparations

U.S.P.

Dose.

Tinctura Catechu Composita ...................................

15 min. 2 fl. dr. (1 8 c.c.)

Trochisci Catechu (1 grain in each ) ...........................

ad lib.

Tinctura Catechu Composita. Compound Tincture of Catechu. - Catechu, 12; cinnamon, 8; diluted alcohol to 100.

Uses. - It is a powerful astringent. It may be employed as an injection in gonorrhoea and gleet. The lozenges are useful in sore-throat, hoarseness, relaxed uvula, and the tickling cough consequent on it (p. 248). Internally it is useful in diarrhoea, and in internal haemorrhages, especially from the uterus (vide also p. 951).

Erythrophlceum. Casca Bark, Sassy Bark. Not officinal.- The bark of Erythrophloeum guinense, a large tree growing on the coast of Africa.

Composition. - It contains an alkaloid, erythrophlceine.

Preparation.

Dose.

Tinctura Erythrophloei (1 in 10)...............................

.5-10 min.

Action. - The powder when inhaled causes violent sneezing. Internally the infusion or tincture causes vomiting and purging. Erythrophloeum has an action on the circulation (p. 273) and kidneys like that of digitalis (p. 430). The alkaloid appears to combine the actions of digitalin and picrotoxin, producing convulsions like the latter. (Harnack.)

Uses. - I have found it useful in dilated heart without valvular disease. It is also useful in mitral disease and dropsy. It has the disadvantage of disturbing the digestion still more readily than digitalis.

Indigo, B.P. C8H5NO. - A blue pigment prepared from various species of Indigofera.

Composition. - Solution of sulphate of indigo. Use. - As a test for chlorine.