396 SCIENCE PROGRESS 



the tax on this export, which is one of the main productions of 

 the country at the present time. This policy would undoubtedly 

 pay with the price of rubber at anything like the present figure. 

 But as far as one can foresee, the more distant future of Brazil 

 as a great rubber-producer must lie largely in its adoption of 

 cultivation. 



At present plantation rubber forms a mere fraction of the 

 world's supply — perhaps 5 per cent. Since 1905, when about 

 200 tons of it were exported from the East, the output has 

 doubled year by year. If this continues the yield in 

 four years' time will be equal to the total annual output 

 of wild rubber at the present time — viz. 70,000 tons. Such 

 a quick rate of increase may not be maintained. Half a 

 million acres, however, will be in bearing in 1914, and, even 

 allowing only a crop of 100 lb. per acre, a low estimate, this 

 would mean an output of 22,000 tons — a considerable part of 

 the world's present supply. In ten years' time the amount 

 of plantation rubber, on a conservative basis, can hardly be 

 less than 100,000 tons per annum. At this period probably 

 supply may begin to overtake demand, with an inevitable 

 drop in prices. Rubber might then descend to 3s. per lb., a 

 price, judging from present conditions, quite remunerative to 

 the planters, but not to the collectors of the wild product. 

 Thus it seems that the world's supply sooner or later will be 

 derived from plantation sources. The possibility of a synthetic 

 commercial caoutchouc appears as far off as ever, and no adequate 

 substitute seems forthcoming. Rubber, then, like the majority 

 of economic plant-products, will in all probability in the near 

 future be obtained largely, if not solely, from cultivated sources. 

 The study, therefore, of the cultivation of rubber trees is of 

 great importance. The methods in use at present for extracting 

 the latex and preparing the rubber therefrom, though fairly 

 satisfactory, cannot be regarded as final. Everything connected 

 with this novel form of cultivation is still in the experimental 

 stage, requiring not only the close attention of the practical 

 agriculturist, but also the services of the botanist, chemist, and 

 physicist, and especially of that much-needed but rarer expert, 

 the biochemist. 



It is the purpose of this article to describe briefly the methods 

 employed on the estates, and to dwell somewhat on the pro- 

 blems connected with them, hoping thereby to arouse a general 



