196 THE AFRICAN RUBBER VINES 



some time in order that the latex may be completely 

 coagulated. They are then cut into lengths and made 

 into bundles, which are carried to a convenient place for 

 treatment. The separation of the bark is effected in 

 different ways in different districts : (1) by beating the 

 diy rhizomes between two stones or upon a block of 

 wood with a wooden mallet ; (2) by soaking the rhizomes 

 in water for two or three days and then beating them 

 as above (this procedure facilitates the separation of 

 the bark, but is stated to affect adversely the quality of 

 the rubber obtained) ; and (3) by stripping off the bark 

 with the aid of a knife. The separated bark is exposed 

 to the sun for several days in order to diy it thoroughly, 

 and is then beaten in a wooden mortar with a pestle 

 of wood, or upon a block of wood with a wooden mallet, or 

 sometimes between stones. By this treatment the bark 

 is reduced to coarse fragments, and the particles of rubber 

 which it contains adhere together and form a loose mass. 

 The beating is continued until as much as possible of 

 the bark has been eliminated from the rubber. The 

 cake of impm-e rubber, sometimes divided into small 

 pieces, is then placed in boiling water for a short time 

 in order to soften it and is again beaten as before. When 

 a mortar and pestle are employed, boiling water is usually 

 poured into the mortar and the beating continued in 

 the presence of the water. This treatment of the crude 

 rubber with boiling water, followed by further beating, 

 facilitates the removal of the vegetable matter, and the 

 process is continued until rubber of the requu-ed degree 

 of purity is obtained. By repeating the operations a 

 considerable number of times, very pure rubber can be 

 prepared by this process ; but as a rule the natives only 

 treat the rubber two or tlu-ee times with boiling water, 

 and consequently the product which they obtahi gener- 

 ally includes a considerable quantity of vegetable im- 

 purity. The cake of finished rubber is usually cut up 

 into small pieces which are placed in boiling water, and 

 whilst still soft are formed by pressure into balls or 

 cylindrical rolls. 



Shnilar processes to the above are also employed by 

 the natives to prepare rubber from the vines, the bark 

 of both stems and roots being used for the purpose. The 

 practice of digging up the roots of the vines for exploita- 



