Blood-sugar Reducing Substance in Yeast 423 



vantage. We have not as yet succeeded in obtaining similar 

 results with Fleischmann's yeast treated in the same way. 



The slow and lasting action of the yeast substance suggests 

 strongly its non-identity with insulin. It seems possible that the 

 substance undergoes slowly a change into insulin. The demon- 

 stration of a blood-sugar reducing substance in various foods 

 will perhaps explain the marked hyperglucemia that one of the 

 authors has described in pigeons on a diet devoid of vitamine 

 B (blood sugar of 30 normal pigeons was found to be 0.170 per 

 cent., of 32 animals fed on polished rice 0,243 per cent., with 

 occasional figures as high as 0.3-0.5 per cent.). It may be 

 that the increase of sugar found is due to deficiency of an 

 insulin-precursor in the food. If this should prove to be true 

 diabetes might be caused by non-functioning of the pancreas, 

 or theoretically, at least, by a deficiency of the insulin precursor 

 in the food. 



208 (2168) 



Extraction of vitamines from yeast and rice polishings using 

 various water-miscible solvents. 



By CASIMIR FUNK, BENJAMIN HARROW and JULIA B. PATON. 



[From the Biochemical Laboratory of Columbia University, Col- 

 lege of Physicians and Surgeons, and the Research 

 Laboratory of H. A. Metz, New York City] 



The comparative values of the following solvents in extracting 

 vitamine from yeast were studied: ethyl alcohol (50, 60, 70, 

 and 80 per cent.), methyl alcohol (60 to 70 per cent.), propyl 

 alcohol (70 per cent.), butyl alcohol (70 per cent.), isobutyl al- 

 cohol (70 per cent.), acetone (70 per cent.), methyl ethyl ketone 

 (70 per cent.) and acetic acid (70 per cent.). The extracts 

 and residues were tested on pigeons and rats, and the extracts 

 were also tested for their content of vitamine D (yeast growth), 

 co-ferment, total nitrogen and total solids. 



If inactivity of residue be taken as a criterion, then 70 per cent. 



