108 THE VITAMINS 



fraction nor the charcoal concentrate obtained by the method of Kin- 

 nersley and Peters (1928) was appreciably inactivated by treating with 

 hydrochloric acid and sodium nitrite, then warming for half an hour 

 and finally boiling a few minutes. 



Whitsitt (unpublished experiments) found that a more drastic treat- 

 ment with nitrous acid than heretofore used seemed to result in a 

 considerable destruction of vitamin B in "protein-free milk." 



That vitamin B may be not wholly resistant to oxidation even at 

 pH 3 or pH 4 is suggested by the fact that Halliday (1929) observed 

 less inactivation of vitamin B when "protein-free milk" was shaken with 

 Lloyd's reagent under an atmosphere of nitrogen than when this process 

 was conducted in air. 



Solubility (Extractability) 



Sandels (1928) studied the solubility of vitamin B from yeast and 

 ground whole wheat in 80 per cent (by weight) alcohol. Four hundred 

 grams of the dry material were treated with 1,500 cubic centimeters 

 of the alcohol, thoroughly stirred, and allowed to stand at room tem- 

 perature (20° to 25° C.) for 24 hours, then filtered through a Biichner 

 funnel and washed with 750 cubic centimeters alcohol, extracted a 

 second time with 1,500 cubic centimeters alcohol, stirred, and allowed 

 to stand again for 24 hours, after which it was filtered and washed as 

 before. The residue was dried at room temperature. The extract was 

 concentrated to approximately one-fourth of its original volume on a 

 steam bath in 2 hours, and dried on cornstarch at room temperature 

 before a fan. 



The 80 per cent alcoholic extract of yeast appeared to contain much 

 the larger portion (about three-fourths) of the antineuritic vitamin 

 originally present in the yeast. The extracted residue, fed in equivalent 

 amounts, was correspondingly inactive. 



On the other hand, the 80 per cent alcohol extract of ground whole 

 wheat appeared to contain about half as much vitamin B as the un- 

 treated wheat, similar growth resulting from supplementing the basal 

 diet 3 times per week with 1.6 grams whole wheat or the alcoholic 

 extract of 3.2 grams whole wheat. 



Alleman (unpublished experiments) finds no difiference in the solu- 

 bility (extractability from skimmed milk powder) of vitamin B, in 80 per 

 cent alcohol and in alcohol of that strength containing 0.1 molar hydro- 

 chloric, benzoic or gallic acid. Bisbey (1930) finds that acidification of 

 alcohol with acetic acid does not increase the solubility of vitamin B 

 either in 80 per cent or absolute alcohol. 



