xii, a, 6 Aguilar: Linseed and Lumbang Oils 237 



Table II. — Comparative drying tests with linseed and lumbang oils.' 



No. of 

 curve. 



Oils used. 



Maxi- 

 mum in- 

 crease in 

 weight. 



Day 

 when 

 maxi- 

 mum in- 

 crease in 

 weight 

 was 

 attained. 



Condition of film. 



1 

 2 

 3 



4 



e 



6 



Linseed, boiled commercial sam- 

 ple. 

 Linseed, raw. of the best quality. 



Lumbang bato, bottled six 

 months. 



Per cent. 

 13.85 



12.13 



11.20 



11.03 



8.30 

 8.92 



1 

 4 

 2 



4 



4 



Perfectly dry, clear, and firm in 



one day. 

 Dry, clear, and firm between 



the fourth and the fifth day. 

 Dry, clear, and firm between the 



second and the third day, tacky 



at the end of twenty days. 

 Dry between the fourth and 



the sixth day. 

 Dry and firm in two days. 

 Dry in four days, but slightly 



opaque. 



Lumbang: banucalag, boiled 



Lumbang: banucalag. fresh 



a Average weight of oil taken was 0.1415 gram. 



The oil films were dry and firm about the time the maximum 

 increase in weights was attained. 



Fig. 1 shows the similarity in the behavior of the three oils. 

 The boiled and the aged oils dry much more rapidly than the 

 fresh oils, and the curves of weight increase are almost straight 

 lines from the origin to the maximum point. On the other hand, 

 the fresh oils dry very slowly the first day, then more rapidly, 

 until the maximum increase in weight is attained. 



Redman and others 6 give 11.7 per cent as the maximum in- 

 crease in weight for linseed oil at the end of the sixth day and 

 10.5 per cent for tung oil between the eighth and the ninth day. 

 Lippert 7 gives 12.4 per cent as the maximum increase in weight 

 for linseed oil. The lumbang oils are, therefore, similar in 

 this respect to linseed and Chinese tung oil. 



Paint films. — The following methods for the preparation of 

 paint films have been tested in the laboratory: 



1. The mercury method consists in allowing a paint to spread 

 on top of mercury and later removing the dried paint film by 

 lifting it off the liquid metal. Films obtained in this manner 



' Redman, L. V., Weith, A. J., Brock, F. P., Journ. Ind. & Eng. Chem. 

 (1913), 5, 630. 



'Lippert, W., Zeitschr. f. angew. Chem. (1898), 412. 



