628 
The Philippine Journal of Science 
1921 
of oleic dibromide (if present) is calculated readily. In carrying 
out these experiments we found that the ordinary commercial 
petroleum ether did not give very good results ; but, by redistill- 
ing the commercial product and using only the fraction boiling 
from 35° to 55°, fairly good results could be obtained. Our 
residue, however, still had a perceptible odor of petroleum ether, 
which we were unable to eliminate by distilling. Probably better 
results could be obtained, if some other solvent suitable for this 
work could be used in place of petroleum ether. 
In investigating the liquid unsaturated acids of lumbang oil 
by means of the bromo-derivative method we performed duplicate 
experiments. The results of these experiments are recorded in 
Tables 4 and 5. In Table 6 is given a summary of the results 
recorded in Tables 4 and 5. 
TABLE 4. — Analysis of liquid unsaturated acids of lumbang oil ( bromo- 
derivative method) . Experiment I. 
Grams. 
Sample of liquid acids 2.8400 
Hexabromide (ether-insoluble bromide) ; melting point, 
178.5° ; bromine content, 63.59 per cent 0.5502 
First crop of tetrabromide ; bromine content, 53.92 per 
cent 0.1308 
Second crop of tetrabromide; melting point, 112° 
to 113° ; bromine content, 53.10 per cent 0.6666 
Residue (dibromide and tetrabromide) ; bromine con- 
tent, 41.80 per cent 3.9546 
Dibromide in residue, 67.23 per cent 2.6586 
Tetrabromide in residue, 32.77 per cent 1.2960 
Total tetrabromide found 2.0934 
Linolenic acid equivalent to hexabromide 0.2019 
Linolic acid equivalent to tetrabromide 0.9778 
Oleic acid equivalent to dibromide 1.6960 
Table 5. — Analysis of liquid unsaturated acids of lumbang oil ( bromo- 
derivative method). Experiment II. 
Grams. 
Sample of liquid acids 2.6372 
Hexabromide (ether-insoluble bromide) ; melting point, 
178° ; bromine content, 63.69 per cent 0.4586 
First crop of tetrabromide; bromine content, 53.78 per 
cent 0.1826 
Second crop of tetrabromide; melting point, 112°; 
bromine content, 53.08 per cent 0.5316 
Residue (dibromide and tetrabromide) ; bromine con- 
tent, 42.04 per cent 3.6032 
Dibromide in residue, 65.83 per cent 2.3722 
Tetrabromide in residue, 34.17 per cent 1.2310 
Total tetrabromide found 1.9452 
Linolenic acid equivalent to> hexabromide 0.1684 
Linolic acid equivalent to tetrabromide 0.9086 
Oleic acid equivalent to dibromide 1.5150 
