in the experiment reported in Table I, the coefficient k t has the 

 value 0.030, using decimal logarithms. At the temperature of the 

 experiment (30C) it was found in a previous investigation that the 

 velocity-coefficient of the mutarotation of glucose, k 2 , had the value 

 0.017, and that the presence of salicin and emulsin in the solution 

 had no effect on k 2 . Substituting the values 0.030 and 0.017 for 

 kj and k,, respectively, in equation (3) the relative number of grain- 

 molecules of fresh glucose (w/A) which were present in the solution 

 of Table I at the different instants when the polariscopic readings 

 were made, have been calculated and are given in column 3 of Table 

 IV. 



TABLE IV. Calculated specific rotation of fresh alacose from salicin. 



In column 2 are the changes of rotation caused by the addition of 

 the sodium carbonate, obtained by subtracting in Table I column 3 

 from column 2. The last column of Table IV gives the specific 

 rotation of the fresh glucose as calculated from the data of columns 

 2 and 3 by the formula which has been given in a former article, 6 



specific rotation = 52. 5 -f f&nw? where 52.5 is the specific rotation of 



stable glucose, 286 the molecular weight of salicin, 180 that of glu- 

 cose, D the change in rotation of column 2, and W the per cent of 

 fresh glucose in gram-molecules from column 3. The average value 

 is 21, and as the specific rotation of /^-glucose has been found by 

 I*oux c to be 20, and that of a-glucose 110, the agreement proves 

 that the form of glucose which is liberated from salicin by the enzy- 

 motic action of emulsin at 30 is ^-glucose. 



J. Amer. Chem. Soc., 1908, 30: 1577. 

 b J. Amer. Chem. Soc., 1908, 30: 1581. 

 cAnn. chim. phys., 1903 [7], SO: 422. 

 [Cir. 47] 



