37 



caoutchouc pass, there can scarcely be a doubt that the elastic 

 substance in each case possesses a very similar, if not identical, 

 chemical structure. Nearly all the latices and similar fluids furnished 

 by plants contain more or less caoutchouc. Even opium, which is 

 the dried juice of the capsule of the poppy, contains caoutchouc, 

 whilst the opium yielded by certain Indian species contains a 

 notable proportion. Chemistry must determine the means by which 

 caoutchouc can best be separated from these relatively poor latices. 

 In view of the increasing production of the nearly pure caoutchouc 

 which is furnished by Hevea brasiliensis, Funtumia elastica, Castilloa 

 elastica, Fiats elastica, and a few other plants which occur or can 

 be cultivated in several of our tropical possessions, the question is 

 not a pressing one at the moment. 



Moreover, it cannot be doubted that chemical science will sooner 

 or later be able to take a definite step towards the production of 

 rubber by artificial means. 



The production of caoutchouc by chemical means has, indeed, 

 virtually been accomplished in its formation from isoprene. The 

 exact nature of this change has still to be determined. When 

 this has been done it will only remain to cheapen the cost of 

 production to make the manufacture of synthetic rubber a purely 

 practical problem. I should be the last to discourage the great 

 extension of rubber planting which is now taking place. It is 

 warranted by the present demand for the material. It has also 

 to be remembered that the actual cost of producing cultivated 

 raw rubber, which is at present about one shilling per pound, 

 will probably be reduced, and the market price of rubber may 

 eventually be so considerably lowered that, as with quinine, the 

 synthetic production could not be profitably carried on. That 

 is a question which involves many factors at present unknown, 

 and only time can decide. Chemists may, however, confidently 

 predict that before the British Association again meets at York 

 the synthetic production of rubber will be a fully accomplished fact. 



As I have said, our science is concerned with nearly every 

 problem connected with the great rubber industry, and in conclud- 

 ing these few remarks I may allude to the production of vulcan- 

 ised rubber depending on the formation of additive compounds 

 of the hydrocarbon with sulphur. In this connection I should 

 mention the recent experiments of Mr. Bamber in Ceylon, which 

 appear to show that vulcanisation may be accomplished by acting 

 on the uncoagulated latex with chloride of sulphur. If this proves 

 to be practicable, it may mean the transference to the tropics of 

 the subsidiary industry of vulcanisation, which is at present carried 

 on in Europe. 



II. 



Notes on these Extracts by H. N. RIDLEY, M.A., F.L.S., Director 

 of Botanic Gardens, Straits Settlements.* 



There are two main points in the paper, one that chemistry 



*Agricultura Bulletin of the Straits & Federated Malay States, Vol. 10, Oct. 1906 

 P- 372. 



