NOTES ON JAPANESE VEGETABLE OILS. 3 



By WiJis' method we usually obtain an iodine value which 

 is a little higher than that obtained by Hübl's method. But 

 owing to the oxidation, which has taken place during the three 

 months, the iodine value obtained by Wuis' method was found 

 to be lower than the value obtained by Hübl's method with the 

 original oil. Determination with WiJis' method was also repeated 

 wdth the eleven months oil, which gave the values 153.6, 151.6 

 and 154.3, mean 153.2, so that during the eight months the 

 decrease of iodine value amounted to 156.3—153.2 = 3.1. 



These experiments show that the fact that the iodine value 

 of Japanese wood oil, which, as above found, is 161.3, or lower 

 than that of linseed oil, can not be ascribed to previous oxidation, 

 as has been believed by many, and that on oxidation the value 

 is much diminished. 



The lowness of the iodine value is also apparent from a 

 consideration of the composition of the oil. This oil, unlike 

 linseed oil, contains none of the highly unsaturated acids, such 

 as linolenic acid CisHgoOo, but consists of the glyceride of elseo- 

 margaric acid and olein, in the proportion, according to Cloëz, 

 of 75^0 of the former to 25?^ of the latter. The theoretical 

 iodine value of the former glyceride being 173.6 and that of the 

 latter 86.2, the calculated iodine value of the oil, assuming the 

 above proportion to be correct, is 151.8. Or, taking the above 

 found iodine value, 161.3, the proportion of the two constituents 

 may be calculated thus, 



173.6 a;+86.2(l-:c)=161.3, .'. a'=0.8592; 

 that is, the oil consists of about 86?^ elœomargarin and 14^^ 

 olein. This proportion, rather than the one given by Cloëz, 

 seems to be justified by the yield of eleeomargaric acid from the 

 oil. 



