Muawin Bark. Erythrophloeum spp.
Muawin Bark.—This is the bark of a Mozambique tree, which in Eastern Africa is used as an ordeal poison. In appearance and structure it closely resembles, the erythrophloeum bark obtained from numerous species of Erythrophloeum (Fam. Leguminosae). An alkaloid, muawine, was discovered in it by E. Merck, 1891. The hydro-bromide, a yellowish powder soluble in water and alcohol. The characteristic test is said to be that with vanadinsulphuric acid, which gives with muawine first a pale green, passing into a pale blue. (H. Jacobsohn, In. Dis., Dorpat, 1892; see also Merck's Jahresbericht, 1891.) According to Jacobsohn, the hydrobromide when injected subcutaneously does not cause any irritation, but produces in frogs symptoms similar to those caused by digitalin, and in warm-blooded animals slowing of the pulse, increase of the heart action, elevation of blood pressure, and contraction of the arterioles. The action of muawine is, therefore, like that of digitalin, but is distinguished by being very temporary.