30 RUBBER 



which flourishes in the forests where the Heveas are 

 found. Various products are turned to account as 

 fuel for curing rubber in other parts of the world, but 

 the results, taken as a whole, have led to a general 

 opinion that the smoke of the palm-nuts used in the 

 Amazon country plays an important part in keeping 

 the rubber of this region first of all rubbers as regards 

 quality ; but the secret of this smoke's special power 

 has not yet been discovered. 



Entrefine or medium Para is made from Hevea milk 

 other than the very richest ; or it may be the result of 

 best quality milk which has only been indifferently 

 well cured. 



Coarse Para, or negro-heads, is uncured or partly 

 cured refuse. When a tree has been tapped, some of 

 the milk in the collecting-cups cakes into a thin crust 

 on the inside of the bowls, and drops fall and congeal 

 on the rim and outer surface. The scraps have to be 

 cleaned off the cups every morning, for new milk loses 

 much of its value if it is allowed to come into contact 

 with dirt or refuse ; sometimes they are thrown away, 

 but frequently they are hoarded in a bag which the 

 seringueiro takes with him on his tapping round for 

 this particular purpose. The refuse is well worth 

 saving, for it will fetch quite a good price as negro- 

 heads. But such coarse rubber is not always an extra 

 source of income to the seringueiro. Sometimes he 

 loses considerably by it, for he finds himself, through 

 no fault of his own, with nothing but this poor quality 

 material as the reward for his day's toil. If it rains 

 hard whilst the trees are being tapped, the latex 

 curdles in the collecting-cups, and the seringueiro has 

 to collect a supply of negro-heads instead of fresh 



