590 Prof. H. E. Armstrong and Mr. H. W. Gosney. [June 13, 



per gramme to neutralise it ; when tartaric acid has been used, as much as 

 7-8 c.c. of alkali may be required ; the product obtained with the aid of 

 sulphuric acid has a still higher acidity and is also less active. 



Very little if any acetic acid is absorbed during the treatment but the 

 amount of tartaric acid fixed is considerable : thus in one experiment, using 



5 grm. of the residue, on titrating the washings, it was found that 15 out of 

 40 c.c. of N/10 acid were retained : on using N/10 sulphuric acid, 22-5 out 

 of 40 c.c. were absorbed. 



Effect of Acid on the Activity of the Enzyme. — The following results were 

 obtained on contrasting the action on 10 c.c. of M/20 solution of succinic 

 ether, to which different amounts of glycine had been added, of 0"5 grm. of 

 enzyme prepared with the aid of tartaric and acetic acid respectively : in the 

 latter case, two different preparations were tested. 



Molecular 

 proportions of 

 glycine 



Percentage hydrolysed by enzyme 

 prepared with tartaric acid 



Percentage hydrolysed by enzyme 

 prepared with acetic acid 







a 



b 







42 -2 



58 -5 



50 -8 



A 



2 



42 -7 



57 '6 



51 -4 



1 



46 -5 



61 -3 



53 -3 



2 



48 -5 



63 -5 



56 -9 



3 





67 -0 





4 



58 -5 





62-6 



5 





70-2 





6 



64-4 





68 -0 



