136 



Scientific Proceedings (127) 



determined that, after this procedure which causes hydrolysis, 

 a considerable quantity of phosphorus is present in the filtrate. 

 This amount agrees closely with that of the fraction which we 

 have termed "non-hydrolysable phosphate." 



66 (2026) 



Further observations on the chemistry of cod liver oil. 



By T. F. ZUCKER. 



[From the Department of Pathology, College of Physicans and 

 Surgeons, Columbia University, New York City.] 



It has been stated previously 1 that the constituent of cod liver 

 oil which influences the mineral metabolism, when cod liver oil 

 is used in treating rickets, is contained in the unsaponifiable 

 fraction of the oil. Further attempts towards isolating the 

 active material have yielded the following results. A good yield 

 of crude product can be obtained by directly extracting cod liver 

 oil with 95 per cent, alcohol. This mixture of fatty acids, a 

 small amount of oil, and other substances, is saponified with 

 sodium hydroxide, and w T hen the calcium soaps are precipitated 

 from an aqueous solution, the unsaponifiable material including 

 the active substance, is precipitated with the soap. From this 

 calcium soap, acetone will extract the active material. In this 

 manner we have obtained preparations of the active material 

 which after a dilution of 1 :1000, are as active as the original 

 cod liver oil. The chemical nature of the substance has not yet 

 been determined, but we believe that we are approaching its 

 actual isolation. 



With regard to the properties of the active material thus ob- 

 tained, we can say that it is not toxic in doses of more than 50 

 times the curative dose. A single large dose in our experiments 

 brought about healing at the same rate as a succession of small 

 doses. The purified active material is entirely free from fat 

 soluble A as shown by the fact that it will not cure xerophthalmia 

 when a subsequent treatment with butter fat does cure the con- 

 dition. 



i Zuckcr, Pappenheimcr and Barnett, Proc. Soc. Kxp. Biol, and Med.. 

 1922, xix, 167. 



