232 



THE ASSAM RUBBER TREE 



two minutes it sets to a cream and complete coagulation 

 occurs. 



It is stated that the latex may be conveniently coagu- 

 lated by adding a 2 per cent, solution of formalin and 

 allowing it to stand. 



Yield of Rubber. — The following figures showing the 

 amount of rubber obtained at the Charduar and Kulsi 

 plantations in Assam will illustrate the yield of rubber 

 furnished by the trees in that country : 



The trees at Kulsi are planted much closer than those 

 at Charduar, and hence the yields per acre are higher. 



In Cachar a number of trees tapped by making numer- 

 ous small cuts with a chisel, as described on p. 230, gave 

 the following results : 



Eight trees planted in 1882 were tapped in 1905-6 and 

 gave an average yield of 6 lb. of rubber per tree. The 

 same trees tapped in 1906-7 gave an average of 5 lb. 

 per tree, the individual yields varying from 2^ to 10 lb. 



Four younger trees, planted in 1899-90, gave an average 

 of about 2 lb. of rubber in 1905-6 and 2^ lb. in 1906-7, 

 the individual yields in the latter year bemg IJ, 2J, 2^, 

 and 3^ lb. 



A four-year-old Ficus elastica in Klang, Federated 

 Malay States, was tapped twice during a year and yielded 

 5 oz. of rubber from the first tapping and 2| oz. from the 

 second. 



It is stated that in Java Ficus elastica can be tapped 

 in the sixth year, and that the amount of rubber obtamed 

 increases with the age of the trees. 



The Forest Service in Java had 12,738 acres planted 



