THE ANTIBERIBERI VITAMINE 



179 



chiefly in combination. This filtrate was then hydrolyzed with 

 sulphuric acid, and the subsequent procedure again repeated. Here 

 too we met with a mixture of pyrimidine bases, among which thymine 

 could be demonstrated, so that finally after a long procedure, only a 



FIG. 41. PIGEOX BEFORE TREATMENT 



FIG. 42. THE SAME PIGEON (CF. FIG. 41) CURED WITH 8 MGM. OP YEAST 

 VITAMINE AFTER Two HOURS 



trace of active substance was found. This observation shows that 

 in working with vitamines, the number of manipulations had best 

 be kept down to a minimum, if results are to be obtained. 



Later on (485, and I.e. 465), we again investigated the vitamine 

 fraction, using 2.5 grams of the crude fraction, obtained from 100 



