45 



cent, of oil (specimen A) whilst the whole seed (husk and kernel 

 ground together) furnished 20 per cent, of oil (Specimen B). 



The oil obtained from the kernels alone is clear, of a light yellow 

 colour, and has an odour somewhat resembling that of linseed oil. 

 It belongs to the class of drying oils and yields a clear, transparent 

 film, when allowed to dry by exposure to air. The husks contain 

 a solid fat, which has a high saponification number and a low iodine 

 value, but since the amount of this solid fat in the husks is very 

 small it makes but little difference to the properties of the oil ob- 

 tained from kernel and husks ground together. The following table 

 gives the constants found for both specimens of the oil, those of 

 linseed oil being added for comparison. 



Para Rubber seed Para Rubber seed 



oil A {from ker- oil B {from 



nets only.) whole seed.) Linseed Oil. 



Specific gravity 



at 15 C 0.9302 u.9310 (, . ( Jji l< -> 0.937 



Free Fatty Acids 



Acid Value 10.7 [9.0 0.8 to c'.(j 



(Calculated as 



OLEIC ACID) 5.4 per cent. 9.6 per cent. 0.4-5.7 per cent . 



Ester value 195-4 l 9°-3 



Neutral Oil 94.6 per cent. 90.4 per cent. 95.5-99. 6 percent. 



Saponification 



value 206.1 209.3 I ^7- I 95 



Iodine value 128.3 1212 160-181 



On saponification with Caustic Soda, Para Rubber seed oil yields 

 a rather soft soap of a yellowish colour. It was found that the time 

 required for the complete saponification of this oil is about half as 

 much again as that required in the case of olive oil. 



Examination of Para Rubber Seed Meal. 



The sample consisted of about seven pounds of finely ground 

 meal of a pale buff colour ; it was free from husk and possessed the 

 pleasant odour characteristic of oil meals. The results of its chemi- 

 cal examination in the Scientific and Technical Department of the 

 Imperial Institute are as follows : — 



Extraction and Examination of the Oil. 



On extraction with light petroleum, the meal yielded 36.1 per 

 cent, of an oil which had a slightly acid odour, and, on standing 

 solidified as a soft crystalline, yellow mass. It furnished the fol- 

 lowing constants : 



Specific gravity at 1.5° C ... ... 0.91 1 



(Acid Value) ... ... ... 130.5 



Free Fatty Acids (Free Acids calculated as oleic acid) 65.6 P cr Cent. 



Neutraf Oil ... ... ... 34.4 



Ester Value ... ... ... 65.2 



Saponification Value ... ... 195/ 



Iodine Value ... ... ... 136.2 



