THE PARA RUBBER TREE 105 



the trees during the collecting season varies from 90 to 

 120 according to the district. It is generally stated that 

 only a very small yield of rubber is obtained from the 

 initial tappings as the latex is at first thick and does 

 not flow freely, but that after several tappings have been 

 made the latex becomes more fluid and the yield of 

 rubber considerably increased. 



The coagulation of the latex is effected in the following 

 manner : The collector makes a small fire over which 

 he places a conical ii*on or earthen chimney which serves 

 to direct the smoke upwards. The fire is fed from time 

 to time with the shells of certain palm nuts which in 

 burning give off dense clouds of smoke containing creosote 

 compounds. The nuts commonly used for this pui-pose 

 are the Urucury {Attalea excelsa) and the Inaja {Maxi- 

 milliana regia). He then takes a round pole of wood 

 about 6 ft. long, which he supports at one or both 

 ends so that the middle portion can be held in the smoke. 

 A small quantity of latex is poured on to the centre of the 

 pole which is immediately turned round and round in 

 the smoke until the latex is completely coagulated, 

 forming a thin film of rubber. This procediu-e is repeated 

 until the whole of the latex obtained in the day's tapping 

 is coagulated and it is continued day by day until a 

 sufficiently large ball of rubber is formed, which is then 

 removed from the pole. These balls of rubber usually 

 weigh from 20 to 60 kilograms (44 to 132 lb.), and, when 

 cut, they are seen to be built up of a number of well- 

 marked concentric layers of rubber each of which repre- 

 sents a day's yield. 



If the smoking has been carefully done so that each 

 layer of latex is completely coagulated, the rubber is 

 classed as " fine " ; if, however, the coagulation is not 

 complete throughout the ball, the rubber is known as 

 " entrefine." A third class of rubber, known as " scrnam- 

 by," consists of the scrap rubber from the incisions, col- 

 lectmg-cups, etc. 



The amount of rubber obtained from the wild Para 

 trees of the Amazon valley appears to vary considerably 

 in the different districts. According to figures published 

 by various observers, the average annual yield of freshly 

 coagulated rubber ranges from about 2 lb. to as much as 

 8 or 10 lb. per tree. The higher yields are obtained in 



