Periodical Literature. 453 



or Aspidosperma quebracho. The former yields the best quali- 

 ties of tannin extract and very durable railroad ties. 



In 1907 there were 28,195 tons of extract exported of which 

 17,733 tons were sent to the United States. The bark, sap and 

 heartwood all yield extract. The bark has 6-8%, the sap 3-4%, 

 and the heart 20-25%. The heart represents two-thirds, often 

 three-fourths of the tree. 



For extracting the tannic acid the wood is shaved into fine 

 pieces, then treated in immense kettles by chemical processes to 

 remove the extract; the fluid is then evaporated into a thick jelly- 

 like mass which is poured into sacks and dried into the solid sub- 

 stance sold in commerce. The industry of manufacturing sleep- 

 ers from this wood has assumed large proportions and large com- 

 panies with modern machinery are sawing out lumber and ties 

 and making extract. One company owns 4,000,000 acres and 

 another turns out 20,000-30,000 sleepers per week. 



The Hardzvoods of the Americas. Bulletin of the International Union 

 of the American Republics. September, 1909. 



For the fiscal year ending June 30, 1909, 



Chicle, there were imported into the United States 



The Basis of 5,450,139 pounds of chicle, valued at $1,- 



Chczuing Gum. 987,112, to be used in the manufacture of 

 chewing gum. Chicle is obtained from the 

 sap of the Achras Sapota tree of the northern South American 

 countries, Central America, and Mexico. The Sapota tree reaches 

 an average height of 25 to 40 feet and reaches maturity at 40 to 

 50 years. A tree 25 years old producing 20 to 25 pounds of gum 

 will be about 22 inches in diameter and 25 to 30 feet high. 



The wood is of a reddish color, closely resembling mahogany, 

 is quite hard, heavy, compact in texture and fine grained. The 

 wood is very durable and in great demand by cabinetmakers. 



The operation of gathering chicle and preparing it for market 

 is similar to that employed in the sugar maple industry in the 

 United States. Under careful management trees have been tap- 

 ped for 25 years. 



As yet the systematic cultivation of the Achras Sapota has not 

 been carried on to any extent, but experiments have shown that 

 trees planted at a distance of 10 feet apart will yield from 5 to 6 



29 



