GUATACUM. This is the name of a genus of small crooked trees inhabiting several of the West India Islands, in low places near the sea. The most remarkable species yields the hard, compact, black-green wood called Lignum Tito, Which is so heavy that it sinks in water, and from which pestles, ship-blocks, rollers, castors, &c., are turned. The same species also produces the gum-resin known in medicine under the name of Gum Guaiacum. For medicinal purposes, the wood should be procured from the central part of the trunk, as being the richest inthe active principle. This wood is very dense, heavier than water, of an obscure greenish fawn colour ; but the recent fracture is yellowish, exhibiting an unequal cleavage, with a fatty shining appearance, if the specimen be good. The wood of the cir cumference is lighter, both in colour and weight, pale fawn, and opake. Genuine gnsiae
wood or lignum vita; is destitute of smell, but if rubbed, and still more if set on fire, it evolves an agreeable aromatic odour. If long chewed, the taste is peculiar, guttural and bitterish. The wood is less used than the resin. Guaiac-resin •exudes spontaneously, or in consequence of incisions, and hardens on the bark. Resin obtained in this way is generally in spherical or long tear-shaped pieces.
G-uaiac possesses the property of stimulating the system generally. It is not prized now so highly as on its introduction into European practice in the sixteenth century, when it bore a most extravagant price, four ducats being often given for a pound. of the wood. It is however a useful medicine, and the wood is applied to many purposes in the arts.