JOURNAL OP THE COLLEGE OF SOIENCE, IMPERIAL UNIVERSITY, 

 TOKYO, JAPAN. 



VOL. XXV., ARTICLE 4. 



Notes on Japanese Vegetable Oils. 



By 



Tokuhei Kametaka, Rigakushi. 



1. Japanese Wood Oil (Kiri-abura). 



{a) The iodine value. 



Whereas Japanese wood oil dries more rapidly than linseed 

 oil, the iodine value of the former is lower than that of the 

 latter. The iodine value of this oil is, however, variously stated 

 by different observers. Thus, it is 169.02 according to K. 

 HiGUCHi, 159-161 according to De Negri and Suburlati, 167 

 (Hübl's method) and 169.5 (Wijis' method) according to Ingle, 

 149.7-165.7 according to Jenkins, and 155.4-165.6 according 

 to Williams. Even the highest value 169.5, given by Ingle, is 

 lower than that (170-188 according to different observers) for 

 linseed oil. H. Ingle (J. S. C. I., 1902, 187) is of the opinion 

 that the lowuess of the iodine value of Japanese wood oil may 

 be due to its previous oxidation, stating at the same time that 

 " there are reasons for supposing that wood oil has a different 

 constitution from the other drying oils." 



In order to examine the fresh oil I procured the seeds of 

 Elœococca vernicia from Echizen and pressed them myself in 

 the cold, taking care to expose the oil as little as possible to 

 the air. The oil pressed out was slightly turbid, so it was 

 passed through a filter paper by the aid of a water-pump. The 



