273 



Saps and Exudations. 



in an of great experience and knowledge, greatly interested in rubber, the very- 

 serious question has arisen as to whether the present mode of curing rubber in 

 Ceylon and the Straits will prove the right oue as quantities increase. 



The theory our friend puts forward is this : — That Ceylon pancakes and 

 Straits sheets are at present made too " pure," that is to say too much moisture, etc., 

 is taken out of the latex with the result that the elasticity and strength is reduced 

 and that it will be found the rubber in this form will not keep, but will inevitably 

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

 raised temperature. He further believes that it is the extra moisture left in the 

 Fine Para, "smoke cured" that renders it fit and strong enough for all purposes, 

 and accounts for it not deteriorating if kept for any length of time. His argument 

 is that the only remedy is for planters to smoke cure their rubber and make it 

 into large balls, bottles or cakes like they do in Para. He further states that 

 there are plenty of nut-producing trees in Ceylon of the Borassus family that 

 when burnt can produce the thick heavy smoke containing the active principle 

 " Creosote " Avhich is the antisceptic that cures the Para rubber in Brazil. 



He predicts that Plantation rubber so cured would fetch rather less than 

 the biscuits and sheets, but that the gain in weight of the moisture left in the 

 rubber would mo^e than make up for the slightly lower price. He thinks that 

 biscuits and sheets will have to be abandoned in favour of balls or other forms like 

 Fine Para comes over in. He argues that the very form of thin biscuits lends 

 itself to heating when under pressure whereas the ball shape and thick biscuits 

 are far less liable, and he prophesies that when the article is coming in tons the 

 defect will be very evident by the state the biscuits and sheets arrive in. 



He adds that even if the rubber does not get heated on the voyage it would 

 inevitably do so if stored for any length of time in warehouse. He gives as proof 

 of his theory that the same thing occurred to certain other rubbers and the remedy 

 in their case was making it into large balls and no further trouble has been ex- 

 perienced. His remedy is smoke curing and he is very positive and emphatic. 

 We ourselves have seen Rangoon and Assam rubber washed and cleaned in India 

 and very nicely prepared, arrive in London a mass of heat and with it the same 

 rubber native cured and a little mixed with earth, &c. quite sound and free of 

 heat, the idea being that the cleaning, etc., weakened and destroyed the fibre 

 of the rubber and rendered it too weak to stand the heat of a ship's hold or varia- 

 tions of the temperature. Apologising for the length of this letter. We are, 

 dear Sir, your obedient servants, 



LEWIS AND PEAT. 



London E.C., March 22nd, 



Commenting on the above letter the Ceylon Observer says :— 



We are well aware that many changes and improvements in the methods 

 of preparing plantation rubber must be made before an entirely satisfactory 

 product results ; there are many objections that can be raised against the present 

 Ceylon product and the method used in curing it. Messrs. Lewis & Peat write 

 us to-day a lengthy letter on the subject; and their conclusion is that to prevent 

 heating of the rubber it must be smoke cured and shipped in a much moister 

 condition than is done at present. Hitherto the dry condition in which plantation 

 rubber has been shipped has been considered one of its characteristics, and it yet 

 remains to be proved that Messrs. Lewis & Peat's adviser is correct when he says 

 that it is " the extra moisture left in the Fine Para, smoke-cured, that renders 

 it strong .... and accounts for it not deteriorating." It may be that smoked- 

 rubber will eventually be adopted but it will have to be by means of machinery, 

 and already one machine has been invented : we refer to Mr. R. C. Dickson's, and 



