DESCRIPTION

Gum Guaiac occurs as irregular masses enclosing fragments of vegetable tissues; as large, nearly homogeneous masses; and occasionally, as more-or-less rounded or ovoid tears. It is externally brown-black to dusky brown, acquiring a green color on long exposure to air, the fractured surface having a glassy luster, the thin pieces being transparent and varying in color from brown to yellow-orange. The powder is moderate yellow-brown, becoming olive brown on exposure to air. It is the resin of the wood of Guajacum officinale L. or Guajacum sanctum L. (Fam. Zygophyllaceae). Gum Guaiac dissolves incompletely, but readily, in alcohol, in ether, in chloroform, and in solutions of alkalies. It is slightly soluble in carbon disulfide.