An extract of the leaves and young shoots of Uncaria Gambler, Eastern Archipelago.

Characters. - In cubes about an inch square, or masses formed of coherent cubes, externally brown, internally ochrey-yellow or pale brick-red, breaking easily with a dull earthy fracture. Taste bitter, very astringent and mucilaginous, succeeded by slight sweetness.

The catechu of the U.S.P.is an extract prepared from the wood of Acacia Catechu, Leguminosae (p. 910).

Composition. - Contains catechu-tannic acid and catechuic acid or catechin, which is related to catechu-tannic acid in the same way as gallic to tannic acid. There is also a yellow colouring matter, quercitin.

Adulteration. - Starch.

Test. - The decoction when cool is not rendered blue by iodine.

Preparations.

B.P.

Dose.

Infusum Catechu (catechu, 160 gr.; cinnamon, 30 gr.; water, 1/2-pint).....................

.1-1 1/2 fl. oz.

Pulvis Catechu Compositus (pale catechu, 4 oz.; kino and rhatany, of each 2 oz.; cinnamon and nutmeg, of each 1 oz...................................................

20-40 gr.

Tinctura Catechu.........................................................................................................

1-2 fl. dr.

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

1-3 or more.

Uses. - Catechu is employed as a local remedy in relaxed sore-throat. It may sometimes be chewed with advantage before taking food by persons suffering from pyrosis. Its use in such cases is probably to diminish the coating of mucus on the gastric mucous membrane. It is also employed in diarrhoea as an astringent (vide also p. 914).