84 Dr. A. D. Waller. Influence of Acids and Alkalis 



Fig. 8. — Effect of propionic acid, N/10, upon A and K. (2412). 



Fig. 9— Effect of a weak alkaline bath (KOH N/20 or 0'285 per 100) upon A 



and K (2360). 



experiments (e.g., in plates 2429 and 2424) the diminution of A/K is 

 principally due to increase of K. 



An increase of the quotient A/K may be by increase of A or by 

 diminution of K. In plate 2360, and in most of my other experi- 

 ments, it is mainly by diminution of K. 



The two plates illustrate the points that acid affects A more than 

 it does K, and that base affects K more than it does A. 



As mentioned above, acid above optimum strength causes a diminu- 

 tion of K ; we may, therefore, say that weak acid causes augmented K, 

 and stronger acid diminished K. 



On testing carefully with very weak acids we shall find that at a 

 strength below the optimum (giving diminished A and increased K, 

 e.g., Plate 2429) the " very weak " acid causes augmented A. We 

 may, therefore, say that very weak acid causes augmented A and 

 rather stronger acid diminished A. And in general summary of the 

 action of acid from, minimal to maximal effective we may state that : — 



