200 



THE VITAMIXES 



The method of Funk and Dubin is still more simple and is briefly 

 as follows: A yeast suspension is prepared by shaking 100 cc. of 

 Nageli solution inoculated with a platinum loop-full of a 48 hours 

 pure yeast culture, preferably bottom yeast. Two test tubes are 



FIG. 48. CENTRIFUGE TUBES USED IN THE DETERMINATION OF THE EFFECT 

 OF VlTAMINE ON YEAST GROWTH 



The tube at the left shows the reading of the blank, while the other two 

 tubes show the readings obtained with different amounts of autolyzed yeast 

 (Funk-Dubin). 



prepared, containing the unknown vitamine solution to be tested; 

 in addition, there are two controls one with yeast suspension alone, 

 and one with the vitamine solution alone. The last control is not 

 very important and serves only to detect the formation of a pre- 



