The heart-wood of Haematoxylum campechianum.

Imported from Campeachy, Honduras, and Jamaica.

Characters. - The logs are heavy, hard, purplish-black externally, reddish-brown internally. The chips (which are the officinal form) are reddish-brown, and have often a greenish lustre; they have a feeble, agreeable odour and sweetish taste; a small portion chewed imparts to the saliva a dark pink colour.

Composition. - The colouring principle of logwood is a crystalline substance, haematoxylin. It is soluble in hot water or in alcohol. Logwood also contains tannic acid, which imparts to it its astringent properties.