660 
Proceedings of the Royal Society of Edinburgh. [Sess. 
-° for *0061 volt - M27. 
= (*015625 x -9692) x _ L =-01192. 
1 *2 7 
Hydrolysis at v = 32 is 32 + ’01192 = '3815, 
and ^=136-0. 
E.M.F. of combination 
N. Calomel. 
A HCl/HoPt. 
1 OQ 1 
N. Calomel. 
N Antliranilic /„ p 
64 Hydrochloride/ 2 ' 
Difference. 
•4001 volt. -3996 volt. ’0005 volt. 
£l for -0005 volt = 1-02. 
c o 
c, = (-0078125 X -9835) x 1-02 = '007839 IST. 
Hydrolysis at v = 64 is 64 x -007839 = -5017, 
and g = 127 '6. 
These values for the hydrolysis constant are much nearer the results of 
catalysis than those of conductivity experiments. 
The Depression of the Freezing-Point by solutions of o-amidobenzoic 
acid as compared with the depression caused by the same concentration of 
hydrochloric acid was then considered as a measure of the number of 
molecules in the solution. 
The degree of ionisation of the hydrochloride was assumed to be the 
same as that of the same concentration of hydrochloric acid. Any extra 
depression must therefore be caused by the free base present, which was 
considered to be un-ionised. Its concentration, and thus the hydrolysis 
of the solution, was then easily obtained from the normal molecular 
depression caused by an un-ionised substance. 
The freezing-point of o-amidobenzoic acid itself proved to be quite 
normal : — 
Concentration. 
Depression. 
Corresponding 
Molecular 
Depression. 
•01717 N. 
•032° 
1-864° 
•0214 
•040 
1-869 
*02205 
•041 
1-860 
Mean 
1-864° C. 
