TANS AND DYES 231 



quebracho tree is unusually hard. The trees cover enormous 

 areas in Argentina, where they occur in almost pure stands. 

 The heartwood of quebracho contains 20 to 25 per cent, of 

 tannin and the extract of this wood gives a reddish color to 

 leather. In 1914 the United States imported 74,cxx) tons of 

 quebracho wood and 93,000,000 pounds of extract of que- 

 bracho. It is one of the hardest known woods. The bark and 

 sap wood are useless for tanning purposes and only the heart- 

 wood is used as a source of tannin. The quebracho logs which 

 are shipped to the United States sometimes come from trees 

 which were 1,000 years old or more. The quebracho extract 

 is called a sweet tan since it does not ferment. It is used in 

 tanning harness, belting, and sole leather. It penetrates leather 

 rapidly and uniformly. 



DIVI-DIVI 



A small leguminous tree (CcEsalpinia conaria), native of 

 Central America and West Indies, produces small twisted pods 

 which are used as a source of tannin and which bear the trade 

 name divi-divi pods. The tree reaches a height of 20 feet 

 and bears white flowers and flat pods about ^ inch wide and 3 

 inches long. These pods yield from 30 to 50 per cent, of tan- 

 nin. Divi-divi pods are used in the tanning industry as a 

 substitute for sumac and oak gall apples. The tree is propa- 

 gated by seed and planted about 16 by 16 feet apart both ways. 

 The pods are picked when fully ripe. Mature trees yield from 

 40 to 75 pounds of dried pods annually. 



LOGWOOD 



This well known dyestuff is obtained from a small legumi- 

 nous tree {Hematoxylon campeckianum) , native of Central 

 America, but now introduced into nearly all parts of the 

 Tropics. At present logwood is produced chiefly in Mexico, 

 Haiti, Dominican Republic, Cuba, and other West Indian Is- 



