382 flnfcia*1Rul>ber Culture in /IDejtco, 



ten years; for from eight cents, the price at which it was sold to ex- 

 porters in 1863, it rose this year (1872) to thirty-five cents a pound; 

 the cost of transportation to the port of shipment, etc., being at the 

 expense of the exporter. 



Rubber is an article which, even assuming that instead of rising in 

 price it were certain to retain its present value, or were even to decline 

 as low as fifty cents a pound, would still yield enormous profits, as will 

 be seen in the following chapter. 



IV. 

 PROFITS OF THE CULTURE OF THE RUBBER-TREE. 



The large profits yielded by the culture of rubber are obvious. 

 Supposing, for instance, a plantation of ordinary size, containing 

 about one hundred thousand trees, will give, at the end of a few years 

 making a low estimate, six pounds of sap a year for every tree ; 

 that sap, reduced to rubber, would lose about one-half by evapora- 

 tion, then each tree would yield three pounds net of rubber. 



From the analysis made by Prof. Faraday, the sap contains only 

 forty-four per cent, of rubber, the balance being composed of differ- 

 ent substances; therefore, supposing that these evaporate, it will re- 

 sult that from one hundred pounds of sap forty-four pounds of rubber 

 will remain. This conclusion agrees with the opinion of Dr. Ure, who, 

 in his Dictionary of Arts, Manufactures, and Mines, says that in re- 

 ducing the sap to rubber there remains forty-five per cent, of the latter, 

 the balance of fifty-five per cent, being lost. 



The number of pounds of sap furnished yearly by each tree being 

 reduced to rubber on that basis, two pounds and a half of rubber 

 would be obtained from each tree, or a revenue of two dollars and a 

 half per tree, if the price was one 'dollar a pound; or of one dollar 

 and twenty-five cents per tree, if the price was fifty cents a pound. In 

 the first case, the plantation would give a return of two hundred and 

 forty thousand dollars a year; and in the second of one hundred and 

 twenty thousand. Admitting that this estimate of six pounds per tree 

 is too high, let it be one-half, one-quarter, or even one-fourth of it, 

 which would be the minimum yield, as will be seen further on, the re- 

 turns of the plantation will be one hundred and twenty thousand 

 dollars, eighty-six thousand dollars, and seventy thousand dollars, re- 

 spectively, in the first case, that is to say, if the price of rubber was 

 one dollar per pound ; and sixty thousand, forty thousand, and thirty 

 thousand, in the second case, if the price was fifty cents a pound. 



It is to be observed, that sixty cents a pound is to-day the average 

 price of rubber in foreign markets, and that, taking into account the 



