CH. XIII] INDIARUBBER, GUTTAPERCHA, AND CAMPHOR 123 



stock exchanges during 1910 that completely overshadowed the 

 eastern boom of 1907. As a result there is now an area of 

 probably 3,250,000 acres or more planted in rubber, chiefly in 

 tropical Asia, and there especially in the Federated Malay 

 States, where a vast area of virgin forest has been removed, 

 and the country has become a rubber country, thanks mainly 

 to the work of Mr Ridley, late director of the Botanic Gardens 

 of Singapore. 



Not only did Mr Parkin work out the wound-response, and 

 thus change what appeared to be only a moderately remune- 

 rative industry into a very profitable one, but he also worked 

 out the way of coagulating rubber into "biscuits," the form 

 in which the bulk of the cultivated Para rubber has hitherto 

 appeared on the market (for the sheets of Malaya are simply 

 larger biscuits). Instead of allowing the latex to run down the 

 tree, and thus become dirty, and instead of allowing it to dry 

 into a mass of dingy black rubber in a coconut shell, he showed 

 that it could be collected in little tins, placed one under each 

 cut, and then mixed, heated, and coagulated by the addition of 

 the calculated amount of acetic or other acid. The milk having 

 been filtered before clotting, this resulted in the formation of 

 clean biscuits free of all tangible dirt, which is so largely 

 present in all the wild rubbers of commerce. These biscuits 

 as a matter of fact lose but little in the washing and drying 

 through which crude rubber subsequently goes. 



During the last ten years an enormous trade in rubber 

 biscuit, sheet, and other forms has sprung up between the 

 Malay Peninsula, Ceylon, and the other equatorial countries of 

 Asia, and the markets of Europe and North America. The 

 following figures of export are of interest in this connection : 



Ceylon 



1901 66 cwt. 



1904 676 



1907 7,093 



1910 32,000 



1912 134,000 



1914 316,000 



1916 488,000 



1918 413,000 



1920 790,000 



