THE AFRICAN RUBBER TREE 165 



hole is filled with latex and covered with a piece of wood, 

 or with plantain leaves, etc., in order to prevent dirt 

 from falling in. The latex is then simply allowed to 

 stand until coagulation has taken place and the mass of 

 rubber produced has become sufficiently fii-m to be 

 handled. The usual time required for this change to 

 occm- is about six weeks. The lump of rubber is then 

 lifted from the hole and allowed to dry entire, sometimes 

 being exposed to the sun for the purpose. As a rule no 

 attempt is made by the natives to remove the excess of 

 liquid from the rubber. The lumps thus prepared are 

 afterwards stored in the roof of a native hut until they are 

 sold to the traders. 



The lumps of rubber vary considerably in size, those 

 from the Gold Coast, for example, measuring from 4 to 

 10 in. in thickness. They consist of dark-coloured porous 

 masses of rubber, which usually contam in their cavities 

 a large cpiantity of the serum of the latex and frequently 

 uncoagulated latex as well. Owmg to the length of time 

 occupied by the coagulation and to the moist condition 

 in which the rubber is left, the proteins present in the latex 

 undergo decomposition, with the result that the rubber 

 develops a very offensive odom-. On account of these 

 defects the West African lump rubbers are of low quality 

 and generally realise less than one-half the price of fine 

 hard Para. 



It is stated that at one time in the Gold Coast the 

 lump rubber was cut into strips and the liquid pressed 

 out, but that the practice was abandoned as the price 

 obtamed was not sufficient to compensate for the loss in 

 weight and the laboiu: involved. 



(2) Coagulation of the Latex by Heat. — In applying this 

 method the natives usually heat the latex in an iron or 

 clay pot over a fire, stirring it with a stick until coagula- 

 tion is complete. In Sierra Leone, where this method 

 of preparation is common, the freshly coagulated rubber 

 is either kneaded in the fingers to press out the liquid, or 

 it is placed between banana leaves and stamped with the 

 feet so as to form a flat cake. The rubber is then cut 

 into thick strips, which are dried and wound into large 

 balls known as " twists." 



The drawback to this method of preparation as practised 

 by the natives is that there is very considerable danger 



