23,6 Perkins and Cruz: Oils in Chaulmoogra Group 555 



work, 8 some of the strongly unsaturated acids contain the chaul- 

 moogric grouping as well as a double bond, these acids would 

 be expected to be very active, but not necessarily in a beneficial 

 way. 



Saponification number.— This was determined in the usual 

 manner, and is expressed in milligrams of potassium hydroxide 

 per gram of oil. It is about 200 in all of the oils studied. 



Acidity. — As none of the seeds were strictly fresh a slight 

 rancidity and corresponding acidity were to be expected. The 

 Taraktogenos kurzii, A (first grade) oil showed surprisingly 

 little acidity, although the seeds were more rancid than those of 

 Hydnocarpus wightiana. Commercial chaulmoogra oil is usually 

 very rancid, and only a small proportion of oil as good in this 

 respect as D, E, and J is to be found on the market. 



Freezing point of the fatty acids.— This was determined in 

 the same manner as the freezing point of the oil, and is a sim- 

 plified titer test. Only the insoluble acids were used, the soluble 

 acids being negligible. The freezing point was quite sharp in 

 most cases and is, therefore, more characteristic than the freez- 

 ing point of the oil. 



The authentic Taraktogenos kurzii samples gave, in this test, 

 the low figures of 22° to 29° for pressed oils and 32° for the ex- 

 tracted oil. This distinguishes them, though not very sharply, 

 from all the other authentic chaulmoogra-group samples, which 

 gave 34° to 39° for the pressed oils and 36° to 55° for the 

 extracted. Hydnocarpus alcalae stands entirely alone, giving 

 a value (55°) 8° higher than that of the nearest competitor, 

 H. venenata (47°) . The remaining five oils range only between 

 34° and 43°. 



The connection between this determination and composition 

 can be shown better later in the paper, when the freezing points 

 of various fractions are discussed. 



Specific rotatory power of the fatty acids. — This value was 

 found by "polarizing" a xylene solution of the fatty acids, using 

 2 grams or 5 grams in 50 mils. The readings were converted to 

 angular degrees, and divided, as is usual for substances in solu- 

 tion, by the concentration and the length of the tube in deci- 

 meters. 



Due to the difficulties in using high concentrations, especially 

 because of the color, these values were not as accurately deter- 



' Power, F. B., and Barrowcliff, M., Joum. Chem. Soc. 87 (1905) 891. 



