Acacia. - Synonym. - Gum Arabic. A gummy exudation from Acacia Senegal Willdenow (nat. ord. Leguminosae).

Habitat

Eastern Africa, principally Kordofan; Western Africa, near the river Senegal.

Characters

In roundish tears of various sizes, or broken into angular fragments, with a glass-like, sometimes iridescent fracture, opaque from numerous fissures, but transparent and nearly colorless in thin pieces; nearly inodorous; taste insipid, mucilaginous; insoluble in Alcohol, but soluble in water, forming a thick, mucilaginous liquid.

Solubility

Slowly but completely soluble in 2 parts of water; insoluble in Alcohol.

Composition

The chief constituent is Arabin, C12H22O11; combined with Calcium, Magnesium and Potassium. This is not affected by lead acetate.

Impurities

Starch, and gum resins.

Incompatibles, - Alcohol, sulphuric acid, borax, ferric salts and lead subacetate.

Acacia is contained in Emulsum Amygdalae, Pulvis Cretae Compositus, and in some Trochisci.

Preparations

1. Mucilago Acaciae. - Mucilage of Acacia. Acacia, 340; Water, to 1000.

Mucilage of Acacia is contained in Mistura Glycyrrhizae Composita and Syrupus Acaciae. Dose, freely.

2. Syrupus Acaciae. - Syrup of Acacia. Mucilage of Acacia, 25; Syrup, 75.

Dose, freely.

Action And Therapeutics Of Acacia

Acacia is demulcent. It is used to suspend insoluble substances, as oils, resins, and insoluble powders. A fluid ounce 30. c.c.of most oils or resinous tinctures requires 3 fl. dr. 12. c.c of mucilage of acacia for suspension, but copaiba requires 10 fl, dr. 40. c.c.. A disadvantage of it is that it is liable to undergo acetous fermentation, which greatly diminishes its emulsifying powers. This may be overcome, to some extent, by making it with tolu or clove water. It may give rise to indigestion and diarrhoea.