242 LEGUMINOS.E 



253- MUCUNA. COWAGE, OR KIWACH, the Hindustan name, vulgarly corrupted 

 into cow-itch. The hairs from the pods of Mucu'na pru'riens De Candolle, 

 a high-climbing plant growing in tropical Africa, America, and India. These 

 hairs are about 3 mm. (% in.) long, stiff, brown-red, and readily penetrate 

 the skin, causing violent itching. Detached from the pod (which forms an 

 article of diet in India) by dipping it in honey and then scraping. An elec- 

 tuary is used in doses of a teaspoonful to a tablespoonful. Cowage acts as 

 an anthelmintic mechanically, penetrating the bodies of the worms and thus 

 irritating and dislodging them. 



254. ARAROBA. GOA POWDER. A mixture of neutral principles obtained from 

 radial fissures in the wood of a Brazilian tree, Andi'ra araro'ba Aguiar. This 

 powder is of a light yellow color, with a somewhat earthy appearance, turning 

 dark brown or purplish on exposure; somewhat crystalline, rough, and mixed 

 with pieces of wood-fiber; inodorous and very bitter. It consists chiefly of 

 chrysarobin (Chrysarobinum). Used externally, in ointments, in skin dis- 

 eases caused by fungi. 



255. ACACIA. ACACIA 



GUM ARABIC 



A gummy exudation from Aca'cia sen'egal Willdenow and of other species of 



Acacia. 



BOTANICAL CHARACTERISTICS. A small tree about 20 feet high, with a gray bark. 

 Leaves bi-pinnate. Flowers pale yellow, in dense spikes. Legumes broad, 

 three to four inches long. 



HABITAT. The acacia tree forms dense scrubby forests in the sandy re- 

 gions watered by the Senegal, and in Abyssinia and Kordofan. 



DESCRIPTION OF DRUG. In roundish, brittle tears or broken fragments 

 about the size of a pea, or larger, with an opaque appearance, due to 

 the numerous fissures. Inodorous; taste mucilaginous and insipid. 

 Soluble in water, forming a thick mucilaginous liquid; insoluble in 

 alcohol. The aqueous solution has an acid reaction and yields gela- 

 tinous precipitates with subacetate of lead, ferric chloride, and con- 

 centrated solution of borax. Oxalates precipitate the calcium base. 

 There are two kinds of "powdered acacia" on the market, the "granu- 

 lated" and the "finely dusted." The former is more soluble and less 

 liable to form lumps, and is, therefore, preferable for pharmaceutical 

 purposes. 



VARIETIES AND GRADES. The Kordofan and Senegal gums are the prod- 

 uct of A. Senegal. The former has been described above. Gum 

 Senegal, deriving its name from the river Senegal, comes in larger 

 tears than the former, varying in color between yellow and yellowish- 

 brown, being less fissured and more transparent. As to the grades 

 of gum, it may be said that the quality entering the market varies 

 exceedingly in its solubility, viscosity of its mucilage, and its color. 

 In the market the grades are designated by numbers, No. i being 

 the best carefully selected tears, No. 2 the next best, and so on until 



