TACKINESS OF RUBBER 79 



the first tappings of a Para tree which is inclined to 

 become tacky, but on the other hand the reverse is the 

 case in the rubber obtained from forest trees of Sapium 

 Jenmani in British Guiana. The rubber from the first 

 tapping of these Sapium trees is usually of excellent 

 quality, whereas that from the succeeding tappings 

 steadily deteriorates in physical properties and finally 

 becomes a soft sticky mass. 



It will be evident from these facts that the question 

 of tackiness in rubber is by no means simple, and it seems 

 probable that the condition may arise from a variety 

 of different causes. 



