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The World's Commercial Products 



wild and there is no check on the greed of collectors. The result is, of course, rapidly to 

 exterminate the trees over any region, and, although high yields are obtained for a while, the 

 supply is soon exhausted. It is the old story of killing the goose which laid the golden 

 eggs, and the result is equally disastrous. Whenever possible this reckless waste is prevented, 

 and more rational methods insisted on. 



In Nicaragua the following method is adopted as described by Belt in his interesting book 



of travels in that country. The collectors 

 having found a tree, construct a rough 

 hanging ladder from the climbing plants 

 common in the jungle, and with the aid of 

 this make, with a cutlass or large knife, 

 V-shaped incisions in the bark, the points 

 of each V being downwards. The " milk " 

 runs out of the cuts and trickles down the 

 trunk to the foot, where it is collected in 

 vessels. A watery decoction obtained from 

 the stems of a wild convolvulus is added to 

 the rubber milk and the mixture stirred, 

 when , the rubber coagulates and forms 

 masses. which float on the surface. These 

 are taken out and kneaded into flat, round 

 cakes,, which are afterwards exported. He 

 states that a large tree, five feet in diameter, 

 yields, when first tapped, twenty gallons of 

 milk, and each gallon gives 2J- lbs. of rubber. 

 Sometimes a continuous spiral cut is 

 made up the trunk down which the juice 

 runs. Other modes are also adopted, but 

 the general result is the same. The method 

 of coagulation also varies. Thus the latex 

 may be boiled, or spread out in thin layers 

 on large leaves and exposed to the air, or 

 alum may be added, the latex of Castilloa- 

 not usually coagulating readily by itself. 



ASSAM RUBBER 



. Few plants are of greater interest to one 

 first visiting the Eastern tropics than the 

 Assam rubber tree, familiar to everyone 

 from the small plants so commonly grown 

 indoors in Great Britain and known as 

 " Rubber plants." In its native haunts in 

 place of a pot plant we see a tree, as tall as a large elm, with a confused and intricate network 

 of curious buttress roots spreading over the ground in all directions, and often apparently 

 several trunks. The latter peculiarity is due to the fact that this tree, like many other 

 members of the fig "tribe, has the power of putting down from the branches slender roots. 

 These, arising from a branch perhaps thirty or forty feet high, descend to the ground, looking, 

 like pieces of smooth twine ; on reaching the ground they penetrate it, tighten up, grow very 

 rapidly in thickness, often equalling, or even exceeding, the original trunk. As several of these 

 aerial roots may be formed and take root, one tree may have at a later stage in its growth 

 apparently several trunks. Like many of the tropical " Figs," it frequently begins its life as a 



By permission of Messrs. Maclaren, Shoe Lane 



FICUS ELASTICA WITH V-SHAPED CUTS 



