GUAIA'CUM, a genus of trees of the natural order zygophyllacecr, natives of the tropical parts of America, having abruptly pinnate leaves, and axillary flowers on one-flowered stalks, often in small clusters. The flowers have a 5-partite calyx, 5 petals, 10 stamens and a tapering style; the fruit is a capsule, 5-angled and 5-celled, or the cells by abortion fewer, one seed in each cell. The trees of this genus are remarkable for the hardness and heaviness of their wood, generally known as lignum vitte, but sometimes as gaaiaeum 'wood, and sometimes as Brazil wood; as well as for their peculiar resinous product, guaiacum, often but incorrectly called guns guaiacans. The species to which the com mercial lignum vitae and guaiacum are commonly referred, is G. officinale, a native of some of the West India islands, and of some of the continental parts of America; a tree sometimes 30 or 40 ft. high, with two or three pairs of ovate, obtuse, and perfectly smooth leaflets, pale blue flowers, a furrowed bark, and generally a crooked stem and knotted branches. It seems probable, however, that other species, as well as this, sup ply part of the guaiacum wood and resin of commerce. At present they are obtained chiefly from Cuba, Jamaica, and St. Domingo. The wood is imported in billets about 3 ft. long and 1 ft. in diameter, of a greenish-brown color. This is the color of the heart wood, the sap-wood is pale yellow. Guaiacum wood is remarkable for the direction of its fibers, each layer of which crosses the preceding diarronally; annual rings are scarcely to be observed, and the pith is extremely small. It sills in water. It is much valued, and used for many purposes, chiefly by turners; ships' blocks, rulers, pestles, and bowls (see BowLs)are among the articles most commonly made of it. When rubbed or heated, it emits a faint, disagreeable aromatic smell; its taste is also pungent and aromatic. Slew.
ings and ra.spings of thewood are bought by apothecaries for medicinal use, The bark is also used in medicine on the continent of Europe, although not in Britain. The-vir tues of both wood and bark depend chiefly on the resin which they contain, and which is itself used in powder, pill, and tincture. It is an acrid stimulant, and has been employed with advantage in chronic rheumatism, in chronic skin diseases, in certain cases of scanty and painful menstruation (and hence it is occasionally an effectual in cases of sterility), and in chronic catarrh. It has also been highly praised as it pre ventative of gout. The resin is an ingredient of the well-known Plummer's pills?. In the 1Gth and 17th centuries, guaiacum was the remedy most in repute for syphilis. The resin sometimes flows spontaneously from the stem of the guaiacum tree; it is sometimes obtained artificially. It is of a greenish-brown color, and has a brilliant resinous frac ture. It has scarcely any taste, but leaves a burning sensation in the mouth. One of its most striking characteristics is, that it is colored blue by its oxidizing agents. It contains guaiacic acid which closely resembles benzoic acid, and yields on distil• lation, certain definite compounds known as guaiaqine, pyroguaiacine, and hydride of guaiacyl.
GUAICUTZtS, Indians of Brazil, near the river and country of Paraguay. They are a hardy race, living mainly by raising cattle. They know little of agriculture, and subsist on fish and other animal food, and wild fruits. They have ranks of slaves, warrior, and a ruling caste. They have the hideous practice of deforming the under lip by inserting in it a piece of wood as large as the palm of a man's hand. The women are hardy, and assist in the chase and fishing.