Gums, Resins, 



278 



situation is in my opinion to try and lend the same properties as regards 

 elasticity and resistibility which now distinguish fine Para to the Ceylon article. 



Note by translator. — I have translated " Widerstandsfahigkeit " which 

 is literally "Power of resistance" as resistibility, perhaps "Resiliency" would 

 have been the more correct technical expression. 



THE GROWTH OF THE RUBBER TRADE. 



In your article on " Growth of the Rubber Trade," published in the Financial 

 and Commercial Supplement of The Times of February 26, you state that the 

 estimated production of rubber in the year 1905 amounted to 65,000 tons, of which 

 Brazil produced 34.000 tons, or rather more than half of the total production. 

 You also state that the area of rubber plantations to date is estimated at about 

 150,000 acres, an area which is rapidly increasing. On the strength of these data 

 you express the opinion that the activity in planting in various parts of the earth 

 makes the outlook less promising for the shareholders in new rubber-growing 

 companies, as the supply will overreach the demand. 



I have had to do with the supply of rubber in my official capacity in India, 

 and I have watched the development of the industry for many years. My 

 experience has taught me two things— (1) that the natural sources are rapidly 

 diminishing, and (2) that to supplant the natural sources we require not less than 

 800,000 acres of plantations. As regards the first point I can, unfortunately, not 

 bring direct evidence referring to Brazil, but the following data regarding British 

 Colonies may prove interesting to your readers : — 



Production of rubber in 1896=12,457,187 lb. 



„ 1904= 5,055,460 lb. 

 This represents a falling-off amounting to 60 per cent. It is my belief that 

 the natural sources are being rapidly worked out. Owing to the natural rubber 

 trees and plants being scattered over enormous areas, it is impossible to insist 

 on a rational treatment of the trees, and they are sure to disappear everywhere 

 within a limit space of time. Hence future supplies must depend on plantations 

 Referring now to the second point, I am confident that to yield permanently a 

 ton of rubber per year requires not less than 10 acres of plantation. Hence to 

 supply 65,000 tons a year, we require 650,000 acres of plantation ; or allowing for 

 some to increase, 800,000 acres. There is^thus plenty of room for further extensions. 

 The danger connected with this industry is the possibility of an efficient substitute 

 for rubber being discovered. 



Oxford. W. SCHLICH. 



— London Times Supplement. 



RUBBER CURING: THE USE OF SMOKE. 



I am, as you know, a rubber planter, having since 1898 planted, near Blue- 

 fields in Nicaragua, nearly 200,000 Castilloa trees, which now measure mostly from 4 

 to 10 inches or more in diameter . . . The coagulation of rubber latex has so far been 

 a difficult problem. Drying in the sun in a moist tropical climate is tedious, and the 

 sun is injurious to Castilloa rubber. Drying out of the sun is not practicable. Drying 

 by steam is expensive and all methods of evaporation yield a Castilloa rubber prone 

 to the viscous disintegration and tackiness, which characterise " Centrals." The 

 same objections, I think, apply to the method of absorption by pouring the milk 

 on blotting paper or porous clays or bricks, followed by my neighbours Belangers. 



