238 TROPICAL AGRICULTURE 



lands. The United States imported 40,000 tons of logwood in 

 1914. The tree is propagated by seed, usually in nurseries, 

 and the young seedlings are then transplanted about 15 by 15 

 feet apart both ways. The trees are felled at the age of 10 

 to 12 years. The bark and white sapwood are removed and 

 the red heartwood is packed in bales or bundles for shipment. 

 The wood yields a red dye known as hematoxylin. 



GAMBOGE 



Several species of the same genus of trees (Garcinia cam- 

 bogia, G. morella, and G. hanburyi) yield the commercial prod- 

 uct gamboge. These trees are native of the East Indies, Cey- 

 lon, Siam, and Cambodia. The gamboge belongs to the family 

 Guttiferae and the tree attains a height of 30 to 50 feet. A 

 yellow viscid latex exudes from incisions made in the bark 

 and dries into a hard mass upon exposure to the air. The best 

 quality of gamboge comes from Siam. Crude gamboge yields 

 about 70 per cent, of a beautiful yellow resin which is soluble 

 in alcohol and is used by painters to give the well known gam- 

 boge yellow. Rarely, gamboge is employed in medicine as a 

 violent cathartic. 



FUSTIC WOOD 



Fustic wood has long been used as a source of yellow and 

 brown dyes for leather and wool. The importation of this 

 wood into the United States since 1905 has ranged between 

 3,000 and 4,500 tons annually. On account of the present 

 scarcity of aniline dyes the importation increased during 191 5 

 to about 14,000 tons, and the value of the wood has also con- 

 siderably increased. 



Fustic wood is obtained from Madura tinctoria, a tree closely 

 related to the osage orange and native of the West Indies and 

 tropical America. The sap wood of this tree is thin and the 

 greater part of the thickness of the trunk is therefore heart- 

 wood, which is light yellow when fresh, gradually turning to a 



