SCIENTIFIC PROCEEDINGS 



Abstracts of Communications. 



One hundred thirty-second meeting. 



Havemeyer Hall, Columbia University, May 16, 1923. 

 President Wallace in the chair. 



206 (2166) 



On the presence of a fat-soluble substance in purified casein. 

 By CASIMIR FUNK. 



[From the Research Laboratory of H. A. Metz, New York City.] 



A sample of casein, purified by three reprecipitations and ex- 

 traction with alcohol and ether in the cold, yields on extraction 

 with boiling alcohol and cooling a fat-like substance, which at- 

 tracted our attention. The crystals obtained proved to be free 

 from nitrogen, melted at 52° and gave no cholesterol reactions. 

 On treatment with boiling alcoholic potash the substance was 

 incompletely saponifiable. Various samples of well purified 

 casein gave 0.5-1 per cent, of this material, whereas A-free 

 casein Harris failed us so far in this respect. 



The question whether the presence of this fat-like product fed 

 along with the casein, plays a role in nutrition experiments, is 

 being taken up in a series of experiments. It follows from the 

 above data, that casein cannot be completely freed from lipins 

 by extraction in cold with alcohol and ether and that the method 

 of purification adopted by the present writer with Macallum 

 (repeated boiling out with alcohol) is probably the most suitable 

 one to use in preparing casein for feeding experiments. 



