The heart-wood of Guaiacum officinale and G. sanctum. St. Domingo and Jamaica. It should be deprived of the sapwood and reduced to chips, raspings, or shavings.

Characters. - The wood is known as Lignum vitae, occurs in logs, and is very hard and heavy. The alburnum, or sapwood, is yellow in colour, the duramen, or heart-wood, is dark greenish-brown, which should become dark blue-green on the addition of nitric acid.

Composition. - Contains resin, chiefly in the heart-wood.