CHEMISTRY. 355 



hydrochloric acid, by sulphuric acid, by phosphoric acid, and by potas- 

 sium acid phosphate is found at about the same hydrogen ion concen- 

 tration. On account of its fundamental importance, this point is being 

 determined with great care by the electrometric method, although the 

 work is ver}^ time-consuming because of the nature of the solutions and 

 the low concentrations of hydrogen ion involved. We plan to follow 

 this by a similar series of experiments upon the influence of neutral 

 electrolytes. 



In the experiments already made it has been found that the optimum 

 acidity is much lower for the amyloclastic than for the saccharogenic 

 action of malt amylase. This observation is of special interest in con- 

 nection with the facts brought out in a comparison of amyloclastic 

 and saccharogenic powers which we published last year (Journal of the 

 American Chemical Society, November 1913). It is planned to make 

 in the future a similar comparative study of the optimum conditions 

 for activation of the amyloclastic and the saccharogenic powers of 

 other amylases. The relationship of these two phases of amylase 

 action to each other and to the proteolytic power which has been found 

 to be such a marked property of the pancreatic amylase bears directly 

 upon fundamental problems of enzyme action in general. 



Two papers dealing with the purification and properties of malt 

 amylase and certain differences between the amylases of the pancreas 

 and of malt are now being prepared for publication, and a paper on the 

 influence of acid activators upon malt amylase will probably follow 

 during the winter or spring. 



Grateful acknowledgment should be made of indebtedness to several 

 collaborators. Miss M. D. Schlesinger has continued to give her entire 

 time to the investigation; Mr. A. W. Thomas has given almost con- 

 tinuous attention to the problem of activation and especially to the 

 electrometric measurements; and at times, during the year. Professor 

 H. T. Beans, Dr. C. F. Hinck, Mr. P. W. Punnett, and Mr. A. P. 

 Tanberg have cooperated in different parts of the work. 



