48 GUTTA CULTIVATION. 



extracted." With these facts in view Mr. Wray sent to Kew, at the 

 end of 1885, a quantity of the dried bark, in order that it might be 

 ascertained whether the residiial gutta could be extracted in this country. 

 The investigation was undertaken, as I informed you in my letter of 

 the 6th August, 1886, by the India Rubber, Gutta Percha & Telegraph 

 Works Company, Limited. I may quote the result: — "After a very 

 careful study of the question they find that though a large proportion 

 of the gutta percha is undoubtedly recoverable, it is so intermixed with 

 a brittle resin that the resulting product is commercially valueless." 



5. This result is, however, not incompatible with the more favour- 

 able results obtained by M. Eugene Serullas. It is quite possible that 

 by acting upon fresh material the gutta percha may be obtained free 

 from deterioration. 



6. The idea, however, of obtaining the residual gutta is not alto- 

 gether a new one. The same problem presented itself in Demerara 

 in the case of gum balata. The late Sir William Holmes attempted, 

 by a method, apparently purely mechanical, to extract the balata 

 from the bark by means of a steam crushing mill. The process was, 

 however, I believe, abandoned, the product being too impure for com- 

 mercial purposes. 



7. The method of extracting the caoutchouc or gutta percha by 

 moans of a solvent is much more promising if it proves practicable, and 

 yields a product the essential properties of which are not impaired. It is 

 not, however, novel. In Geae, Mr. Sowerby, the Secretary of the Botanical 

 Society of London, appears to have suggested to Mr. Thomas Christy a 

 plan for growing the African rubber vines " in plantations and cutting 

 down the stems yearly." The stems were then to be crushed and 

 digested with bisulphide of carbon in which the rubber is soluble. The 

 subject was briefly referred to in the Kew Report for 1877 (p. 32). I 

 do not remember meeting with any account of the method being carried 

 out practically. 



8. Gutta percha is a siibstauce which is at present of first-rate 

 importance to civilisation. The trees which yield it are confined to a 

 very limited area on the earth's surface ; they are of slow growth, and I 

 believe, at present, no steps are being taken to plant them so as to 

 provide for the gutta percha supply of the future. The exhaustion of 

 this important product would seem to be within a measurable distance. 

 The experiments of M. Serullas, in as much as, if successful, they will 

 economise the yield, appear to me to deserve every encouragement. 



I am, etc., 



(Signed) W. T. Thiselton-Dyer. 



The Hon. R. II. Meade, c.b., 



Colonial Office. 



In tlie year 1892 Messrs. Eigole and Serullas took out 

 patents for the extraction of gntta percha from the leaves by 

 the bisulphide of carbon process, for the " acid which is the 

 main secret of the invention " mentioned by Sir Cecil C. Smith, 



