121 



THE DRYING OF RUBBER. 



I cannot say that I altogether like the method Air. BURGESS pro- 

 poses for the drying of rubber. Calcium chloride is at the best a 

 very expensive material to use in this connection, and with its use 

 comes the danger of accidental contamination with the rubber. Very 

 great care would require to be exercised that not a particle of it got 

 into contact with the rubber, for the evil resulting would be very 

 great. Of the two methods he proposes, certainly the circulation of 

 dried air is by far the better, but this could be obtained more safely 

 and more economically than by the use of calcium chloride, i have 

 no intimate knowledge of how careful the native labourers are, but 

 from what I have heard, I would be disposed to think that sooner or 

 later accidents would happen and a batch of rubber be spoiled by 

 admixture with this chemical. I still remain of opinion that the 

 system of drying in vacuum is by far the best suited to the needs of 

 the planter. As Mr. BURGESS is in a much better position than I 

 am to conduct practical experiments on this, I would gladly give him 

 any details and help that I can. So far as I can see, no difficulties 

 stand in the way, and the drying is brought about so rapidiy as to be 

 economical, and the machine so arranged as to be practically " fool- 

 proof. " I shall be glad if Mr. BURGESS will communicate with 

 me in regard to this and other matters. 



Sir W. THISEL TON DYER. 



India-Rubber Journal, Vol. XXIX, p. ijj. 



I do not think that there is much fear, as suggested by Sir WIL- 

 LIAM ThiSELTON Dyer, that the calcium chloride process will in 

 any way cause risk of injury to the rubber during the course of 

 drying. We have here been using the chemical in a make-shift 

 way in small trays put into drawers with the rubber, and cannot say 

 that even handled by Malay boys we have had any serious accidents 

 with it. In cases where a little slopped over the rubber it produced 

 a patch of stickiness. If the calcium chloride is cleaned off imme- 

 diately it does no harm. If left on, however, it destroys the rubber 

 by making a sticky soft patch. But, in a manufactory on a large 

 scale, where the calcium chloride would be in pans, well away and 

 above the rubber, there need be no risk. The whole apparatus 

 could easily be made fool-proof, and there would be no more risk 

 than from fire or any other catastrophe. The expense is not great 

 as the calcium chloride is quite cheap and practically lasts for ever 

 except for a little accidentally wasted by overset or something of 

 that sort. 



However, as long as smoked rubber fetches the same price as 

 white biscuits unsmoked, smoking is certainly simpler and about as 

 quick a method of preparation. 



But, it will be strange, indeed, if the engineers cannot invent a 

 drying apparatus with unheated air to dry the rubber in the quickest 

 possible time. 



Editor. 



