136 



It would be hard to say why Mr. Strickland's trees all died 

 under the operation, it may have been that the method of tapping 

 employed was too severe, and the trees were unable to recover 

 from the shock; or the wounded surface may have been attacked 

 by a fungus. One who had seen the trees would be able to form 

 a much better opinion as to the cause. 



After the outer rough bark has been stripped off, the inner bark 

 remaining is very thin, compared with that of Para, and conse- 

 quently much greater care is required in tapping or the cambium 

 is bound to be injured. 



The latex of "Ceara" is treated in the same way as that of 

 "Para" and the rubber to all outward appearance is as good. 



The outer rough bark of " Ceara" can be stripped off at all seasons 

 of the year in the Malay Peninsula without any apparent injury 

 to the tree. But in India where long droughts are experienced it 

 might not perhaps be wise to strip it off during the very dry season, 

 as the dry air and hot sun might have some injurious effect on the 

 tender bark freshly exposed. 



The "Ceara" is not a tree for the Malay Peninsula. It does well 

 in a young state and up to 20-25 years, when it begins to show 

 signs of decay and in a year or two dies right off. I do not know 

 why this should be, but have heard it suggested that the excessive 

 rainfall of the Peninsula does not suit it. One of the oldest trees 

 at Kuala Kangsa is now going off in this way. It carries very few 

 leaves and those, on the tree look sickly, and good portion of the 

 trunk on one side has decayed. In previous cases where this decay 

 of old trees was noticed the trees had never been tapped. 



J. W. CAMPBELL, 

 Superintendent Govt. Plantation^ 



Perak. 



ANALYSES OP RUBBERS. 



A number of specimens of commercial rubbers were analysed by 

 Mr. D. SPENCE and the results published in the Quarterly Journal 

 of the Institute for commercial research in the tropics of Liverpool 

 University (No. 2 p. 75). The samples were crude and had under- 

 gone no treatment before analysis. The method of analysis, was to 

 cut up the rubber very fine and dry it in an air oven over Calcium 

 chloride at 55c. until constant in weight. It was then extracted 

 with acetone and the extract dried and weighed. The residue again 

 dried and digested with chloroform till complete solution of the 

 caoutchouc took place, after being allowed to settle till the coagul- 

 ated proteid had settled out, the chloroform evaporated and the 

 caoutchouc dried and weighed. 



