48 



COMPOSITION OF LATEX 



Para latex containing 32 per cent, of caoutchouc had a 

 specific gravity of 1018 at 60° F. Beadle and Stevens 

 examined a large number of specimens of Para latex from 

 eight-year-old trees, and their results show specific gravi- 

 ties ranging from 0973 to 0-980 with a mean of 0975 ; 

 they also found specific gravities of 0-975, 0974, and 0-975 

 for tlu-ee specimens of Rambong latex {Ficus elastica). 

 Spence gives the specific gravity of a specimen of Funiumia 

 elastica latex containing only 20 per cent, of caoutchouc 

 as 0-9989, and Fickendey records a value of 0-988 at 

 25° C. for the latex of tliis species. A sample of Landolphia 

 owariensis latex examined at the Imperial Institute had 

 a specific gravity of 0-956. 



Composition o£ Latex. — The latex as it exudes from 

 the stem is usually slightly acid, but it may be neutral, 

 or even faintly alkaline. 



In addition to the globules of rubber substance, latex 

 always contains varying amounts of resin and protein, 

 and the aqueous liquid holds in solution various salts 

 (organic and inorganic), free organic acids, carbohydi'ates, 

 and other substances. The following analyses of Para 

 latex which have been recorded by Bamber and by Beadle 

 and Stevens will indicate its general composition : 



Beadle and Stevens have also recorded the following 

 analyses of the latices of Rambong {Ficus elastica) and 

 Castilloa trees grown in the IMalay Peninsula : 



* Mineral matter, f Four-year-old trees, % Ten-year-old trees. 



