PARA RUBBER. 



105 



The filtrate from such material is composed of water, caoutchouc, 

 resins, proteids, sugars, gums, insoluble substances, and mineral mat- 

 ter. The amount of water in pure latex varies considerably, but it 

 is usually estimated at 50 to 56 per cent. The latex from trees which 

 have been frequently or heavily tapped usually contains a much high- 

 er proportion of water ; in some instances even as much as 90 per cent, 

 of water is present. The latex collected during the dry months 

 of February and March at Henaratgoda contains much less water 

 than that obtained from the same trees in the rainy season. The 

 following table will serve to indicate the general range in composi- 

 tion according to the analyses of Seeligmann,* Lascelles Scott, and 

 Baniber : — t 



Analyses of the Latex of Hevea Beasiliensis 



The above analyses show the general composition of the latex of 

 Hevea brasiliensis and the different classifications adopted by chem- 

 ists. The analyses by Lascelles Scott is one of a latex of unnamed 

 origin, but Weber accepts it as being not far from the truth for our 

 species. There is an indefiniteness about several of the constituents, 

 which are grouped under such general heads as proteids, resins. 



It will be noticed that the caoutchouc varies from 32 to over 41 per 

 cent., and the other constituents such as resin, sugar, insoluble sub- 

 stances and the ash show considerable variation. This is not surpris- 

 ing, as the latex examined in each case was obtained from a different 

 count ly and the ages of the trees were probably quite different. 

 Furthermore, the methods of extraction of the latex involve the 

 cutting of bark tissues to different depths, and the inevitable mixing 

 of liquids would account for much variation in the soluble impurities. 



Caoutchouc Globules. 



The caoutchouc exists as globules in suspension. When pure it is 

 practically colourless, and is much lighter than water. It consists 

 essentially of carbon and hydrogen, and belongs to a class of bodies 

 known as terpenes. It is insoluble in water, but according to Weber 



* India Rubber and Gutta Percha, by Falconet, Seeligmann, and 

 Torrilhom, 1903, p. 84. 



j Bamber, Circular R. B. G., June, 1S99. 



(H) 



