Active Ingredients. - Pale catechu contains between thirty-six and forty per cent. of tannic acid, and the important substance "catechine" or "catechuic acid," CI3H12O5 (Rochleder).

The first named, catechu-tannic acid, is soluble in cold water. Exposed to a moist atmosphere, it turns dark red, and becomes insoluble.

Catechine is a modification of tannin. It changes the persalts of iron to grayish green; crystallizes in snow-white silky needles; is soluble in boiling water, alcohol, and ether, but very sparingly soluble in cold water, which apparently simply softens it, and causes it to swell up. Heated, it becomes fusible. It very slightly reddens litmus. From tannic acid it differs in not affecting a solution of gelatine. The sweet taste of catechu is said to depend upon the presence of the catechine.

Physiological Action. - Pale catechu appears to act upon the human organism as a simple and mild astringent.

Therapeutic Action. - Catechu is a very excellent astringent, both for taking internally and for application to the surface. As an internal astringent, it is employed in affections of the mouth and throat, such as relaxed uvula and the troublesome cough induced thereby, and relaxed sore throat. For these purposes it may be sucked or chewed, or employed in the form of lozenges. Catechu may also be chewed as a remedy for atonic dyspepsia, especially when much trouble is given by pyrosis. It may be given, too, in cases of diarrhoea and chronic dysentery, but should be avoided if there be acute inflammatory symptoms, haemorrhages, mucous discharges, and incontinence of urine. Catechu, in a word, may be employed in most cases where astringents are indicated. It is often prescribed in conjunction with chalk-mixture, opium, and other narcotics. The best time for administration is half an hour or so before meals.

The powder of pale catechu is sometimes sprinkled upon indolent ulcers with good effect.

The infusion injected up the nostrils often stops epistaxis.

Preparations And Dose. - None officinal. The following, from the B. Ph.: Catechu Pallidum, gr. x. - xx. (.60 - 1.25); Pulvis Catechu Comp., gr. xx. - xl. (1.25 - 2.50); Tinct. Catechu, 3 j. - ij. (4. - 8.); Infus. Catechu,

Pale Catechu Nauclea Gambir 41

- ij. (30. - 60.); Trochisci Catechu, No. 1 - 3.