1838.] Report on the Caoutchouc Tree of Assam. 137 



This plan is simple, and far superior to that of incising the trunk 

 as it ensures greater cleanliness. The larger roots are preferred in ad- 

 dition to their being half exposed, for yielding a richer juice. 



The fluid on issuing is, when good, nearly of the consistence of 

 cream, and of a very pure white. 



Its excellence is known by the degree of consistence, and the quantity 

 of caoutchouc, on which this would appear to depend, is readily ascer- 

 tained by rubbing up a few drops in the palm of the hand, when the 

 caoutchouc rapidly becomes separated. By kneading this up again, it 

 rapidly becomes elastic. 



Many incisions are made in one tree. The juice flows rapidly at 

 first, but the rapidity diminishes after a few minutes. 



It is said to flow fastest during the night : it continues during two 

 or three days, after which it ceases, owing to the formation of a layer 

 of caoutchouc over the wound. 



The quantity obtainable by the above method from a single tree has 

 not yet been exactly ascertained. Some of the natives affirm that four or 

 even five maunds may be procured; others only give one ghurrah full 

 or ten seers as the amount procurable. From the slowness with which 

 it flows, I should consider half a maund to be a fair average produce 

 of each bleeding. The operation is repeated at the expiration of 18 or 

 20 days. Assuming the rate of half a maund to be nearly correct, 

 20,000 trees will give as the aggregate of four bleedings 12,000 maunds 

 of caoutchouc, that is if Dr. Roxburgh's proportion of this product to 

 aqueous matter, viz. 15| oz. to 50, be correct. 



I should however, observe that the proportion of caoutchouc in the 

 American juice is given by Dr. Faraday as 45 in 100*, or nearly one 

 in two. On the excellence of the Assamese products as compared with 

 that of America, it does not become me to pronounce. If strength, elasti- 

 city, clearness and freedom from viscidity as well as from foreign matter 

 be test of excellence, then this product may be considered superior to any 

 other hitherto manufactured. Nothing can in fact well exceed, at least 

 in these points, the best specimens manufactured by Mr. Scott. It has 

 been pronounced by persons resident in Calcutta to be excellent, and the 

 only objection that has hitherto been raised against it on sufficient ex- 

 amination is that of Mr. Bell, who says it snaps. But if by this we 

 are to understand snapping from being allowed to return to its original 

 dimensions from the state of tension, the objection amounts to an excel- 



* Mechanic's Magazine, 24, 440. Mr. Scott finds that the proportion varies 

 from four to six parts in 10, the variation depending probably on the part of the 

 tree from which the juice is extracted. 



