272 



Prof. J. Walker. 



[Oct. 19, 



ordinary way, is evidently the sum of the concentrations of the 

 substances containing X, since this by hypothesis undergoes neither 

 association nor dissociation. The total concentration is therefore 



or r --= 



since b + c = a + d* and b is vanishingly small in an acid solution. 



The following table contains the values of a and d multiplied by 

 10 5 , and is an extended and corrected form of the table given on p. 160 

 of the original paper, for which it is to be substituted. 



10~ 5 . 



This table shows even more plainly than the original one the 

 peculiarities noted in the previous paper. When the numbers it 

 contains are used to calculate the apparent dissociation constant &o> it 

 is found that the values up to &&/K= 10 undergo no alteration (p. 162). 

 The new values for the other ratios are as follows : 



x 10 5 calculated from a = a + d/5 and a = 



These numbers are only slightly different from those previously 

 obtained. 



Turning now to the calculation of & for the amino-benzoic acids, the 



* Loc. cit. t p. 158. 



