508 



Dr. E. F. Armstrong. 



[Apr. 5, 





Table XL 







Table XII. 





Maltose, 5 per 



cent. 



Maltose, 10 per 



cent. 



t. 



X. 



K. 



t. 



X. 



K. 



1 hr. 



7-3 



0-0329 



1 hr. 



4-7 



0-0209 



2 hrs. 



13-9 



0-0325 



3 hrs. 



11-7 



0-0180 



4 „ 



24-4- 



0-0304 



5 „ 



17-8 



0-0170 





31-7 



0-0229 



23 „ 



23-9 



0-0052 



23 „ 



35-2 



0-0082 



28 „ 



25-0 



0-0045 









47 „ 



31-4 



0-0035 



Concentration of Hydrolyte. — Although the experiments recorded in 

 Tables I — XII furnish evidence that the rate of change decreases as 

 the concentration of the sugar solution is increased, while the actual 

 weight of sugar hydrolysed increases ; as the experiments were made 

 at different times and with different materials, it was necessary to 

 carry out a strictly comparable series in which the amount of sugar 

 present was the only factor varied. Table XIII shows the results 

 obtained in experiments with relatively concentrated solutions of milk 

 sugar and lactase in which the amount of enzyme present was quite 

 small. As the concentration of sugar was increased, the rate of change 

 diminished so that the fraction of sugar hydrolysed in a given time 

 was inversely proportional to the amount of sugar present — so that 

 a constant weight of sugar was changed independently of the con- 

 centration — a result which is in agreement with Adrian Brown's 

 observations with invertase. 



Table XIII. — Amount of Sugar Hydrolysed. 



Solutions 

 containing — 



24 hours. 



46 hours. 



144 hours. 



Propor- 

 tion. 



Weight. 



Propor- 

 tion. 



Weight. 



Propor- 

 tion. 



Weight. 



20 „ 



14 -2 

 7-0 

 4-8 



1 -42 

 1 -40 

 1 -44 



22 -2 

 10-9 

 7-7 



2-22 

 2 -18 

 2-21 



33 -4 

 16-9 

 11 '0 



3-34 

 3-38 

 3-30 



Table XIV relates to a series of experiments made with emulsin 

 and milk sugar in which, however, the proportion of emulsin taken 

 was not particularly small. Although the rate of change decreased as 

 the concentration increased, the experiments afforded no evidence that 

 a constant weight of sugar was hydrolysed in a given time inde- 

 pendently of the concentration. In a second series, however, in which 

 a considerably smaller proportion of enzyme (see Table XV) was used, 



