346 Messrs. A. Harden and W. J. Young. [June 10, 



VI. Specific Character of the Inductive Action of Fructose. 



This inductive effect is specific to fructose and is not produced when 

 glucose is added to mannose or fructose, or by mannose when added to 

 glucose or fructose, under the proper conditions of concentration of phosphate 

 in each case. 



The experiments on this point were carried out by ascertaining in each 

 case the excess of phosphate necessary to produce a slow rate of fermenta- 

 tion and then making two parallel experiments, one with, and the other 

 without, the addition of the small quantity of the sugar to be tested for 

 inductive power. All the observations were made with 15 c.c. of yeast- 

 juice. 



Table X. — Specific Character of the Inductive Effect of Fructose. 





Cubic 





Grammes of sugar present. 







No. of 



centimetres 



Total 









Gas 



Time. 



experiment. 



- 6 molar 



volume. 









evolved. 





phosphate. 





Mannose. 



Fructose. 



G-lucose. 











c.c. 









c.c. 



mins. 



31a 



15 



' 37 



1 











8-7 



30 



b 



15 



37 



1 



o-i 







43 3 



30 



c 



15 



37 



1 







o-i 



10 -9 



30 



32a 



10 



32 



1 











18 -9 



30 



b 



10 



32 



1 



o-i 







76 -3 



30 



33a 



60 



82 -5 







1 







13 -6 



20 



b 



60 



82 -5 



0-15 



1 







7-9 



20 



34a 



10 



30 











1 



11 -4 



30 



b 



10 



30 



o-i 







1 



14 -1 



30 



35a 



75 



90 







2 







18 -4 



30 



b 



75 



90 







2 



o-i 



16-1 



30 



This remarkable property of fructose, taken in connection with the facts 

 that this sugar in presence of phosphate is much more rapidly fermented 

 than glucose or mannose, and that the optimum concentration of phosphate 

 for fructose is much higher than for glucose or mannose, appeal's to indicate 

 that fructose when added to yeast-juice does not merely act as a substance to 

 be fermented, but, in addition, bears some specific relation to the fermenting 

 complex. 



All the phenomena observed are, indeed, consistent with the supposition that 

 fructose actually forms a permanent part of the fermenting complex, and that, 

 when the concentration of this sugar in the yeast-juice is increased, a greater 

 quantity of the complex is formed. As the result of this increase in the 



