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 dear, 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 her- oil B ( from 
nils only.) whole seed.) Linseed Oil. 
Specific gravity 
at 15 0 C 
Free Fatty Adds 
Acid Value 
(Calculated as 
Oleic Acid) 
Ester value 
Neutral Oil 
Saponification 
value 
Iodine value 
0.9302 
10.7 
54 per cent. 
*954 
94.6 per cent. 
206.1 
128.3 
0.9316 
19.0 
0.931 (o 0.937 
0.8 to 8.9 
04-5.7 P er cen< - ■ 
9.6 per cent 
190.3 
90.4 per cent. 95.5-99.6 per cent 
209.3 
121 2 
187-195 
1 6 o-l 8 I 
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 : 
i°C ... 
Specific gravity at 
(Acid Value) 
Free Fatty Acids (Free Acids calculated as oleic acid) 
Neutral Oil 
Ester Value 
Saponification Value 
Iodine Value 
0.91 1 
130.5 
65.6 per cent. 
344 
65.2 
*957 
136.2 
