329 



with a sample of fine Para. Both samples were subjected to the 

 same treatment, and as will be seen by the following figures, the re- 

 sults, obtained were practically identical. 



Name 

 of Sample. 



Malayan 

 Fine Para 



Breaking Strain 



Weight. Extension. Pull. 

 58 lb. 9i ins. 21 lb. 



58 lb. gh ins. I9i lb. 



Elasticity and Recovery. 



Permanent set 

 Pull after after 5 

 5 minutes, minutes rest. 



I/i lb. 10 

 17 lb. 8 



The only point in favour of Fine Para is in permanent set after 

 five minutes extension and five minutes rest. The figures given re- 

 present set of 7.81 and 6.25 per cent., so that in this respect there is 

 1.56 per cent, advantage to Fine Para. Against this must be put 

 lYz lb. in the third column and 5^ lb. in the fourth column. These 

 represent 7.I and 2.8 per cent, resistance to pull in favour of Malayan 

 rubber. All these differences are, however, so slight that were a 

 number of tests instituted they would doubtless practically disappear. 

 We may, I submit, conclude as the result of these most interesting 

 experiments, that when Malayan plantation rubber is prepared in the 

 same way as Brazilian rubber, the two substances are indistinguish- 

 able in quality, and that there is the strongest probability that they 

 are the product of one and the same species of Hevea. 



As people may hastily jump to the conclusion, from the above- 

 stated facts, that the only way to prepare Para rubber so as to retain 

 its best characteristics is the Brazilian method, I may add that at the 

 same time and under the same conditions a sample of Malayan un- 

 smoked sheet plantation rubber, coagulated by the acetic acid 

 method, was also vulcanized and tested, and the results obtained 

 were much higher than those of either of the two rubbers already 

 mentioned. I cannot give the name of the producing company, nor 

 the details of the tests and manufacture, until the consent of the com- 

 pany has been obtained. 



The conclusion which these and other tests so gener^^usly made 

 by the Continental Rubber Company of New York, during the Exhi- 

 bition, forces upon me is the urgent necessity of the Mid-Eastern 

 rubber planters having a properly equipped vulcanizing and testing 

 laboratory of their own, where the many problems connected with 

 the growing and preparation of rubber could be worked out, and the 

 quality of their product the by raised and standardised. I had the 

 opportunity of meeting and talking to many manufacturers at the 

 Exhibition, and what they all seem to require is a rubber of a definite 

 character, so that before they buy, say, a hundred ton lot, they will 

 know exactly how to treat it without wasting time and money in bul- 

 king it and in experimental work. This points to the necessity of 

 concerted action on the part of the planters. 



L. Wray. 



