IS, 6 
West and Montes: Lumbang Oil 
631 
ing, quality of film, and the percentage change in weight when 
drying. They did not, however, determine any of the oil con- 
stants during the drying process. 
The ability to absorb oxygen may be regarded as an indica- 
tion of the drying power of an oil. We have carried out ex- 
periments on the oxidation of lumlbang oil by allowing a slow 
current of dried air to pass through the oil which was heated 
to a certain temperature and stirred constantly. The apparatus 
was arranged in the following manner : A glass salt bottle con- 
taining about 400 cubic centimeters of lumbang oil was placed 
in a water bath which was heated to a temperature of 80°. The 
glass bottle contained a stopper having three holes. Through 
one hole passed a stirrer operated by a hot-air motor. The 
second hole held an entrance tube reaching to the bottom of 
the bottle and drawn out to a fine opening. The third hole 
contained a short exit tube also drawn out to a fine opening. 
A slow current of air was passed through a Drechsel wash bot- 
tle containing concentrated sulphuric acid, after which it was 
passed through three tubes containing soda-lime, and then into 
the oil. The experiment was started each morning and discon- 
tinued at night. At frequent intervals samples of about 15 cubic 
centimeters were taken and these were later analyzed by deter- 
mining various constants such as the iodine and saponification 
numbers. This method of procedure enabled us to follow the 
changes caused by slow oxidation. The results of these experi- 
ments are recorded in Table 9. 
. Table 9 . — Constants of lumbang oil blown at 80° C. 
As a result of continued oxidation the oil gradually became 
slightly darker in color and very thick and viscous, and the 
specific gravity increased considerably. The figures in Table 9 
