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Scientific Proceedings (130) 



sary solutions, 10 c.c. of each being inoculated with 0.5 c.c. of 

 yeast suspension obtained from the 14th sub-culture. After 

 suitable incubation, the growth was measured in millimeters by 

 the centrifuge method. The results were as follows : 



TABLE I. 



Growth in mm. 







after 3 days 



4 days 



1. 



Medium consisting of purified ingredients 









(Medium P) 



1.5 



1.5 



2. 



Medium P with ordinary sugar replacing 









purified 



5.0 



5.0 



3. 



Medium P with ordinary salts replacing 









purified 



1.5 



1.5 



4. 



Medium P with ordinary water replacing 









purified 



1.5 



1.5 



5. 



Medium 0 plus one drop autolyzed yeast. 









Viability test 



25.5 



23.5 



6. 



10 c.c. sterile water plus 0.5 c.c. yeast 









suspension 



1.4 



1.5 



7. 



Same as No. 6, but with yeast killed be- 











1.0 



1.0 



These results prove that the cane sugar was the only vitamine 

 D bearing factor in the medium and hence to this factor our 

 whole attention was directed. The cane sugar was recrystallized 

 three times from alcohol and each fraction tested in conjunction 

 with the usual salts and distilled water. The same yeast sus- 

 pension was used as in the previous experiment. 



TABLE II. 



Growth in mm. 

 after 3 days 



1. Medium O 6.12 



2. Medium O with once recryst. sugar replacing ordinary 



sugar 2.5 



3. Medium O with twice recryst. sugar replacing ordinary 



sugar 2.37 



4. Medium O with thrice recryst. sugar replacing ordinary 



sugar 2.12 



5. Medium O plus one drop autolyzed yeast 23.0 



6. Medium P plus ash from one gram of ordinary sugar 2.12 



7. 10 c.c. sterile water plus 0.5 c.c. yeast suspension (killed) 2.0 



We have also tested the activity of the residue obtained from 

 the concentrated mother liquors, and found that this concentrate, 

 when purified and added to medium P, influenced the growth of 



