GUAIACUM OFFICINALE. OFFICINAL GUAIACUM, OK LIGNUM VITAL 
Class X. DECANDRIA.— Order I. MONOGYNIA. 
Natural Order, ZYGOPHYLLE^E. THE BEAN-CAPER TRIBE. 
This tree, the wood of which is well known in England under the name of Brazil wood, or Lignum 
vita, is a native of Jamaica, Hispaniola, and the warmer parts of America. It has been long in use, and 
appears from the MSS. of Sir Hans Sloane, in the British Museum, to have been first cultivated in this 
country by the Duchess of Beaufort in 1699. It is said to flow*er from July to September. 
The tree rises to the height of thirty or forty feet, and is near a foot in the diameter of its trunk, with 
numerous divaricated knotty branches, leafy at the ends. The bark is very smooth, variegated with green 
and white; that of the branches being uniformly ash-coloured, striated, and marked with fissures. The 
wood is hard and ponderous, dark, olive-brown within, whitish towards the bark, and has a peculiar acid 
aromatic scent. The leaves are opposite, abruptly pinnate, consisting of two or three pairs of ob-ovate or 
roundish, obtuse, entire, smooth, dark-green, rigid, leaflets, various in size, with several radiating veins, and 
nearly sessile. The flowers are pale blue, on simple, axillary, clustered stalks, shorter than the leaves. The 
calyx consists of five ovate-oblong, obtuse, concave, spreading deciduous leaves; the two outer ones rather 
the smallest. The petals are five, roundish, ob-ovate, concave, spreading, with short linear claws, inserted 
into the receptacle. The. stamens are ten, awl-shaped, erect and villous, with oblong incumbent, cloven 
anthers ; the germen is obcordate, with a short awl-shaped style. The capsule is somewhat turbinate, on a 
short stalk, smooth, succulent, pale, ferruginous or yellow, with from two to five rounded, slightly bordered 
angles, and as many cells bursting at the angles ; but two or three of the cells are frequently abortive. The 
seeds are solitary, pendulous, ovate, convex on one side, angular at the other, the albumen cartilaginous and 
chinky, the embryo nearly straight with thickish cotyledons. 
Guaiacum is a barbarous name, derived from the Spanish one Guaiae or Guayacdu, which itself origi- 
nated from Hoaxacan, the Mexican appellation of the plant. 
Qualities and Chemical Properties. — The wood of this tree, and the peculiar matter wdiich it 
yields, are the parts medicinally employed. The wood is hard and heavy, and is much used for ship-blocks 
and for toys. It is nearly inodorous, but has a warm, somewhat bitter taste ; and its virtues depend upon 
the resin-like substance which it contains. It is rasped for medical use, but we are inclined to think that it 
yields little of its powers to decoction. 
The Guaiacine exudes spontaneously from the trunk and branches of the tree; and concreting, forms 
tears of a semi-pellucid and pure nature. By making incisions in the month of May, greater quantities 
flow, and after becoming hard, by exposure to the sun and air, it is collected and packed in casks for ex- 
portation. Another method for obtaining it, is by sawing the trunks and large limbs into billets, about 
three feet long: an auger hole is then bored lengthways in each, and the other end of the billet being put 
in a fire, the melted matter flows into calabashes, placed purposely to receive it. By boiling chips, or 
raspings of the wood in water, with common salt, the Guaiae swims at the top, and may be skimmed off. 
Sometimes it is adulterated with common resin and the Machineel gum. The former is detected by its 
smell, if heat be applied, and the latter “by adding to the alcoholic solution a few drops of sweet spirits of 
nitre, and diluting with water ; the guaiae is precipitated, but the adulteration floats in white striee.” 
Guaiacum was considered by chemists as a resin, till Mr. Hatchett observed, that when treated with 
nitric acid it yielded products very different from those of resinous bodies. This induced Brandeto examine 
its chemical properties in detail. To his valuable paper we are indebted for almost all the accurate infor- 
mation which we possess respecting its chemical nature. 
“ Guaiacum is a solid substance, resembling a resin in appearance. Its colour differs considerably, 
being partly brownish, partly reddish, and partly greenish ; and it always becomes green when left exposed 
to the light in the open air. It has a certain degree of transparency, and breaks with a vitreous fracture. 
When pounded it emits a pleasant balsamic smell; but has scarcely any taste, although when swallowed it 
excites a burning sensation in the throat. When heated it melts, and diffuses at the same time a pretty 
strong fragrant odour. Its specific gravity is 1*2289. 
“When guaiacum is digested in 'water a portion of it is dissolved, the water acquiring a greenish-brown 
colour and a sweetish taste. The liquid, when evaporated, leaves a brown substance, which possesses the 
properties of extractive ; being soluble in hot water and alcohol, but scarcely in sulphuric ether, and forming 
precipitates with muriates of alumina, tin, and silver. This extractive amounts to about nine parts in the 
hundred of Guaiacum. 
