LIGNUM-VITae, or Guaiacum is a very hard and heavy wood. It is shipped from Cuba, Jamaica, St. Domingo, and New Providence, in logs from 2 1/2 to 36 in. diameter, and is one of the heaviest of the woods. Col. Lloyd says that it grows in the Isthmus of Darien to the size of 5 or 6 ft., and is there called Guallacan, and that it is one of the most abundant woods of the country. When first cut, it is soft and easily worked, but it becomes much harder on exposure to the air. The wood is cross-grained, covered with a smooth yellow sap-like box, almost as hard as the wood, which is of a dull brownish green, and contains a large quantity of the gum guaiaeum, which is extracted for the purposes of medicine. Lignum-vitse is much used in machinery, etc. for rollers, presses, mills, pestles and mortars, sheaves for ship-blocks, skittle-balls, and a great variety of other works requiring hardness and strength. It was employed by the Spaniards for making gun-carriages and wheels.

The fibrous structure of this wood is very remarkable: the fibres cross each other sometimes as obliquely as at an angle of 30 degrees with the axis, as if one group of the annual layers wound to the right, the next to the left, and so on, but without much apparent exactitude.

The wood can hardly be split, it is therefore divided with the saw; and when thin pieces, such as old sheaves, are broken asunder, they exhibit a fracture more like that of a mineral than an ordinary wood. The chips, and even the corners of solid blocks, may be lighted in the candle and will burn freely from the quantity of gum they contain, which is most abundant in the heart wood.

The Bahama lignum-vitae has a very large proportion of sap-wood, pieces of 8 or 10 inches diameter have heart wood that scarcely exceeds 1 or 2 inches diameter. One variety of cocoa-wood and also the almond-wood are somewhat similar to lignum-vitae.

There are two species, Guaiacum officinale and G. sanctum, both of which probably yield the lignum-vitae of commerce. This name is also sometimes applied to the wood of Arbor vita.