PARA RUBBER. 139 



at present made too pure — too much moisture being taken out of the 

 rubber — with the result that the elasticity and strength are reduced ; 

 such rubber, it is stated, will not keep, but inevitably becomes soft 

 and treacly if stored for any time or subjected to pressure and a 

 raised temperature." It is finally suggested that the Plantation 

 rubber should be smoked and made up into large balls, bottles, or 

 cakes, as in Para. The same firm in their circular dated December, 

 1.905, state that " the very greatest care should be taken that all rub 

 ber is absolutely dry before being packed. ' ' b viously , in the opinioi i 

 of Messrs. Lewis & Peat, the question of how to prepare the rubber 

 for the market is a vexed one and deserving of much experiment. 



It has been pointed out. elsewhere, how Para rubber is smoked 

 in Brazil, and in addition to the nuts of specified palms certain 

 antiseptic reagents such as creosote, dilute hydrofluoric acid, and 

 corrosive sublimate have been mentioned as being of use in the 

 preparation of rubber. It has also been shown that rubber prepaied 

 from trees 30 years old may, if not properly dried, become quite 

 as heated or tacky as that from young trees. If a larger 

 proportion of moisture is left in Plantation rubber, putrefactive 

 changes will be more apt to occur, and the use of antiseptics either 

 by direct application to the latex or by smoking or coating the 

 lubber will be imperative. In any case, the coating of the rubber 

 particles or smoking the freshly-prepared rubber biscuits or sheets 

 with any antiseptic is always an advantage as far as the keeping 

 properties of the rubber are concerned ; inost of the heating or 

 tackiness in Plantation rubber is due to bacteria, which can 

 be prevented from spreading by the use of antiseptic.* ; if not 

 destroyed they will lead to putrefactive changes in rubber with which 

 they are brought into contact. It is really a disease which in 

 unsmoked rubber can certainly be spread by contact ; but whether 

 it is more likely to develop on rubber from young or old trees, is still 

 a point to be determined. If the consumers will accept the Planta- 

 tion rubber, prepared by the use of antiseptics as described, the 

 producers will find no difficulty in meeting their requirements ; in 

 fact, several Ceylon estates have, for some time past, sent their 

 rubber to Europe in the smoked condition, but whether better 

 average prices for large quantities have been obtained is not known 

 to the public. 



The subject of Plantation versus wild fine Para has been discussed 

 in a recent issue of the " German Rubber Trade Journal," by Gus- 

 tave van der Kerckhove, and, as in other communications, the writer 

 points out that fine Para has not been deposed by the plantation 

 product, and that the former probably owes its better physical 

 properties of elasticity, durability, &c, to the creosote emitted 

 during the smoking process. 



Chemical and Physical Tests. 

 The inferiority of Plantation rubber is commonly attributed to the 

 trees being immature as compared with (hose in the Amazon District. 



