National Geographic : 1897 Mar
RUBBER FORESTS OF N1CARAG UA AND SIERRA LEONE 87 is passed. " plug up " the tubes of that season with wood that has been dipped in some liquid insecticide and saw off the tube and its wooden core even with the thin exterior bark of the tree. The coagulation of the milk-like exudation and the separation from it of the elastic material can be effected by heating to 167 to 175 degrees F. and stirring in a hot decoction of some species of convolvulaceae, as morning glory, or stirring into the emulsion, when fresh and hot, the smoke from burning palm or other oleag inous nuts, which are abundant in rubber-yielding districts. Secondary crops, planted between the rows of rubber-produc ing trees, could be the Liberia coffee tree, bananas, or such fibrous plants as hennequen, sisal, etc., of the agave family; also, the vanilla bean, one vine to each rubber tree, which would yield an annual crop equal in value to the rubber product. While the vanilla vine needs trees of this class for sustenance, yet it is probable that the vanilla would not materially reduce the flow of sap or the quantity of elastic material from the tree. A comparative estimate of the annual value per acre in Nica ragua of coffee trees and rubber trees at nine years of age and thereafter, at present (1896) prices, gives $192 net profit from an acre in rubber trees. RUBBER FORESTS OF SIERRA LEONE The following information concerning the undeveloped rubber forests of Sierra Leone is drawn from the address of His Excel lency Colonel Cardew to the legislative council of Sierra Leone on his journeys, aggregating 1,300 miles, in the hinterland and protectorate of Sierra Leone in 1894-'95. There are large forests with abundance of rubber awaiting ex ploitation by intelligent and systematic methods and that will yield wealth to the first enterprising comer. An extensive rub ber forest lies between Makali and Kruto, covering the greater part of the district between the Sell and Bagwee rivers. This area comprises portions of the .Kuniki and Koranko districts, and the extent of the rubber forests is estimated at 600 square miles. The portion of the forests seen is composed of rubber trees about ten years old, called " Kewatia." These trees grow rapidly, and in ten years attain a girth of two or three feet, but under present methods they are felled by the rubber-gatherer. Two vines, the "nofe " and the "lilibue," yield rubber, the latter of the choicest quality. The "nofe" is invariably cut up and destroyed for its rubber, and the "lilibue " generally so.