X. A, 2 Bj'ill and Agcaoili: Philippine Oil-bearing Seeds 115 



At the end of the experiment both had become thick and gummy 

 with none of the original oily appearance, while cato oil, on 

 the other hand, showed very little change in its weight and 

 practically no difference in its physical properties when treated 

 thus. The above oils were heated to 270"" C. and held there for 

 fifteen minutes. The sample of lumbang bato used suffered a 

 loss of 1.5 per cent in weight, but showed no deposit of foots 

 on cooling; lumbang banucalag lost 0.8 per cent and showed a 

 slight deposit of foots; cato oil lost 1.6 per cent of its original 

 weight and deposited a small amount of foots when allowed to 

 stand. All three darkened somewhat. Seventy-five hundredths 

 per cent precipitated lead and 0.75 per cent manganese borate 

 were added to each, and they were then heated on the water 

 bath for three hours. Only a part of the dryer went into so- 

 lution, but the effect on the lumbang oils was decidedly marked. 

 When the "boiled" oils were spread evenly on glass plates and 

 placed in a horizontal position in a box protected from dust in 

 subdued light at room temperature, lumbang banucalag oil dried 

 to a clear film in five hours, while lumbang bato oil underwent 

 a like change in six hours. Cato oil did not dry and at the end 

 of twenty days remained wet and without having undergone 

 any noticeable change in consistency. These experiments de- 

 monstrate that the lumbang oils are drying oils of good quality 

 and capable of taking a dryer ; cato oil, on the other hand, shows 

 no improvement when treated thus. 



Further drying tests were arranged for the native oils under 

 conditions approxim.ating those existing when the oil is used for 

 painting purposes, to determine the rate of drying and the 

 change in weight. These changes are demonstrated in figs. 1 

 and 2. The oils were spread evenly on glass plates 7.5 by 4 

 inches in size, previously weighed and again weighed when 

 covered with the oil film. They were then placed in a horizontal 

 position on racks in boxes, the sides of which were made of a 

 good quality of cheese cloth. This prevented the entrance of 

 dust, insects, etc., but allowed a free passage of air. They were 

 weighed each morning. Duplicates were run in all cases, and 

 the average result is plotted. In figs. 1 and 2 the time in days 

 is plotted along the horizontal axis and the per cent increase 

 along the vertical axis. 



133958 2 



