E: V. McCollum and N. Simmonds Rt 
Period 2.—Ration: Same as Period 1 plus the alcoholic extract of 15 
gm. of ether-extracted cooked beans. 
Period 3.—Ration: Same as Period 2, but with the extract increased to 
equal 40 per cent of beans in the food mixture. 
This illustrates the difficulty of complete extraction of the 
dietary factor B from beans by alcohol after cooking. 10 per cent 
of beans furnish enough of this substance for normal growth dur- 
ing 7 weeks, but the alcoholic extraction is so incomplete when 
cooked beans are employed that the extracts used in this experi- 
ment were not hee 
7 aaScoe LOT San 
Four} 
Weeks | 
Lot 972 B. eerad 1.—Ration: Purified food mixture plus 5 per cent of 
butter fat. 
Period 2.—Ration: Same as Period 1, but with the residue of 25 per 
cent of cooked beans, after extraction with ether and then with alcohol. 
110 
{04 Se a 
30 
This experiment supports the evidence afforded by Chart 9, 
Lot 999 A and by Lot 999 B, that the failure.of the alcoholic ex- 
tract of cooked beans to induce growth is due to physical changes 
‘in the bean during cooking whereby the water-soluble B is pro- 
tected from contact with the solvent and not because of destruc- 
tion of the physiologically active substance. 
Preparation of the Extract and Residue Employed with the Rations 
of Chart 9, Lots 999 A, 999 B, and 972 B.—1,176 gm. of cooked 
navy beans were extracted with alcohol-free ether for 18 hours 
and then with 95 per cent alcohol in three consecutive 6 hour 
. periods, removing the flask with the extract at the end of each 
period to prevent excessive heating. - The first 12 hours’ extrac- 
THE JOURNAL OF BIOLOGICAL CHEMISTRY, VOL, XXXIII, NO. l 
