CAOUTCHOUC 



425 



Pur us, Jurna, &c. The tree is also largely cultivated in Ceylon, the 

 Straits Settlements, &c. 



In the collection of the latex, spiral, herring-bone or isolated 

 incisions are made in the bark of the trunk and the latex collected. 

 This latex consists of globules of caoutchouc with small quantities of 

 other bodies held in suspension by proteid substances ; it is treated in 

 various ways for the production of rubber. 



In Brazil the small tin cups in which the latex has been collected 

 are emptied into calabashes which the collector carries to his hut. 

 Here he has a pole, about the length of a broomstick and thickened 



FIG. 235. Sampling Para rubber ; in the centre balls of Para rubber cut 

 transversely, showing the central hole. 



for a few decimetres at a little distance from one end, supported 

 horizontally on a cross-bar. Under the thickened portion a clay dome, 

 or sheet iron cone, is placed in which a fire is kindled on to which 

 palm nuts are thrown. The latex is emptied into a large basin and 

 a little is poured by means of a dipper on to the thickened part of the 

 pole. This is now rotated in the dense smoke of the burning nuts. 

 The latex is rapidly coagulated by the acetic acid in the smoke to a 

 layer about 1 mm. thick, the creosote and other tarry substances from 

 the smoke acting as preservatives. The coating and coagulation is 

 repeated again and again until a short, thick, cylindrical mass weigh- 

 ing usually from 3 to 30 kilograms, but sometimes much more, has 

 been obtained. The pole is then removed and the ball hung up to 



