268. Guaiaci lignum, N.F.—Lignum vitae.
268. GUAIACI LIGNUM, N.F.—LIGNUM VITAE. The heart-wood of Gua'iacum officina'le and G. sanctum Linné. Greenish-brown, resinous raspings or chips, mixed with yellowish particles of the sap-wood; odor slight, agreeable, increased by heating or rubbing; taste slightly aromatic, but irritating and persistent after chewing some time. The heart-wood of guaiac is imported in billets or logs and used for turning out various instruments and utensils, the shavings from these being used in pharmacy. The sap-wood is yellowish, the heart-wood dark greenish-brown, hard and heavy, remarkable in that its specific gravity is such as to sink in water.
Constituents: The resin (soluble in alcohol and alkaline fluids) is the most important constituent, of which it contains about 26 per cent.; it also contains 0.8 per cent. of bitter, pungent extractive. The wood or chips are turned a bluish-green by the action of nitric acid fumes.
Stimulant, diaphoretic; also a reputed antirheumatic and antisyphilitic. Generally given in the form of compound decoction of sarsaparilla. Dose: 15 to 60 gr. (1 to 4 Gm.).