THE ANTIBERIBERI VITAMINE 195 



McCollum and Simmonds (I.e. 315), does not affect the activity of 

 vitamine B, and this has recently been confirmed by Funk and Dubin 

 (I.e. 493) who also showed that the substance stimulating the growth 

 of yeast was not destroyed by reduction with palladium and hydrogen, 

 as well as with zinc and hydrochloric acid ; neither was it affected by 

 oxidation with finely divided platinum and oxygen for 7 to 8 hours. 

 Besides this, we (512) showed in 1916 that the action of radium in 

 doses used in radium therapy is without destructive influence on vita- 

 mine B originating from autolyzed yeast. In accord with this, there 

 is the work of Zilva (513) who investigated the effect of ultra-violet 

 light on this substance. Contrary to the above findings, Sugiura 

 and Benedict (514) report that large doses of X-rays of radium almost 

 obliterates the vitamine of autolyzed as well as dried yeast. Weill 

 and Mouriquand (515) carried out analogous experiments with 

 Rontgen rays on barley kernels. 



DEMONSTRATION AND ESTIMATION OF ANTIBERIBERI VITAMINE 



At the outset of vitamine investigations, only one method was 

 available for the demonstration of vitamine B. Beriberi was pro- 

 duced in chickens and pigeons (the latter being more commonly 

 used) by feeding white rice, and then the preparation to be tested 

 was given either per os or intramuscularly. 5 The latter method had 

 the advantage of giving a more speedy effect and of making it certain 

 that the solution was utilized by the animal, and had not trickled 

 out of the beak. A negative finding of this therapeutic measure 

 did not entirely indicate that the solution to be tested was inactive. 

 Negative results may be due to the fact that the animal had pro- 

 gressed too far to be affected by the above measures or they might 

 be due to the presence of toxic products. It was chiefly through the 

 efforts of Osborne and Mendel, as well as McCollum and his co- 

 workers, that the second method was then developed, of which we 

 have already spoken in the chapter on the vitamine requirements of 

 rats. This method consists in adding the preparation to be tested 

 to a diet complete in everything but vitamine B. If growth was 

 obtained with young rats, then the presence of this vitamine was 



6 We were one of the first to make use of the parenteral administration of 

 this vitamine. Unfortunately, we have been unable to discover in the liter- 

 ature by whom this method was first introduced. 



