1904] Studies on Enzyme Action. 5?1 



is known to be true both of cane sugar and of maltose. Our 

 experiments show that it is equally true of milk sugar. Using a half 

 normal (J gramme molecular) solution of HC1, we have found that K has 

 the following values : — 



Table VI. 



Concentration of sugar. K. 



9 per cent 2-88 



18 „ 3-53 



27 „ 4-10 



From these figures the following empirical law may be deduced 

 connecting K withj?, the concentration in grammes per 100 c.c. : 



K - 2-27 (1 +0-03^). 



. Arrhenius has calculated a similar expression from Spohr's results 

 for cane sugar, viz., K = 19*26 (1 + 0-0131 p). 



It would, therefore, appear that the rate at which hydrolysis takes 

 place is more than twice as much influenced by changes in concentration 

 in the case of milk sugar than in that of cane sugar. 



Influence of the Products of Change. — The influence of the products of 

 change on the rate of hydrolysis is of particular interest in view of the 

 results obtained with enzymes. In the case of acids the products 

 accelerate instead of retarding the change but they exercise no selective 

 influence ; moreover, about the same effect is produced by the addition 

 of equal weights of glucose, of galactose or of milk sugar or even of 

 the equivalent quantity of a neutral salt. 



Table VII. 

 Amount added to 18 per cent, solution 



of milk sugar (K — 3" 53). K. 



9*0 grammes milk sugar 4*10 



9*0 „ glucose, 1st expt 3'89 



9-0 „ „ 2nd „ , 4-06 



9*0 ,, galactose 4*14 



3*7 „ potassium chloride 3*79 



Hydrolysis by Sulphuric Acid. — Several experiments were made, with 

 an acid equivalent in strength to the chlorhydric acid used in the 

 experiments previously referred to. 



VOL. LXXIII. 



