



TABLE III. Real course of the hydrolysis of salicin by emulsin, temperature SO C\ 



This experiment also shows a satisfactory constancy for k r 



THE FORM OF GLUCOSE WHICH IS LIBERATED FROM SALICIN 

 BY THE ACTION OF EMULSIN. 



From the fact that the addition of alkali to the salicin solutions 

 which are undergoing hydrolysis causes an increase of dextrorotation, 

 it may be concluded that the glucose which is liberated from the 

 salicin is less dextrorotatory than 52, the rotation of stable or alka- 

 line solutions of glucose. Only one form of glucose is known which 

 has such lower rotation, namely, /^-glucose, of specific rotation 20. 

 That this is indeed the form which is liberated from salicin may be 

 accurately shown as follows: Start with A molecules of salicin in 

 unit volume of solution at constant temperature and let there be 

 present at the time t, w molecules of fresh glucose and y molecules 

 of stable glucose. The rates of formation at the time t are: 



(1) For fresh glucose, dw/dt = k t [A-w-y] k 2 w. 



(2) For stable glucose, dy/dt = k 2 w. 



In these expressions k x is the velocity-coefficient of the real rate of 

 hydrolysis, and k 2 is the velocity-coefficient of the mutarotation of 

 glucose. The solution of these equations under the conditions which 

 obtain (that at the time zero, w, y, and dy/dt are all zero) is 



(3) w = A 



' " 



] 



k 2 kj 



a This mathematical treatment is closely analogous to that previously used in 

 studying the inversion of cane sugar by invertase. See J. Amer. Chem. Soc., 1908, 

 SO: 1576. 

 [Cir. 47] 



