80 



FOREST PRODUCTS 



It is extensively used for railway cross ties in Argentine where it is said 

 to resist decay for over fifty years. The tree is generally small and poorly 

 shaped; the quebracho forests resembling the live-oak stands of the 

 southeast and southern California. Individual trees are generally only 

 from 15 to 30 in. in diameter and 20 to 40 ft. in total height. Its center 

 of production is now in rather remote districts along the Parana River, 

 where the forests are very scattered and open. When seasoned, the wood 

 is cut and converted into logs for shipment with great difficulty on account 

 of its exceeding hardness. 



The tannin is found chiefly in the heartwood, although the sapwood 

 and the bark as well contain small percentages of it. Excepting chestnut, 

 it is the only wood which has been developed and used on a large scale 

 for this purpose, all the other materials consisting of bark, leaves, or other 

 parts of the tree. 



A number of analyses of the percentage of tannin contained in que- 

 bracho wood give the following results: 1 



The wood is generally accredited with 20 to 28 per cent of tannin. 

 One analysis of the wood gave the following results: 1 



The first of the above tables indicates that the tannin content of the 

 sapwood and bark is so low, and the weight of the wood so great, that it 

 is only profitable to transport the heartwood long distances to market. 



1 From " Tanning Materials of Latin America," by T. H. Norton, Department of Com- 

 merce, 1918. 



