648 Proceedings of the Royal Society of Edinburgh. [Sess. 
XXXIX. — Hydrolysis of Salts of Amphoteric Electrolytes. By Miss 
Heather Henderson Beveridge, B.Sc., Carnegie Research Scholar. 
Communicated by Professor James Walker. 
(MS. received June 12, 1909. Read June 21, 1909.) 
Different experimenters on the degree of hydrolysis of amphoteric 
electrolytes in acid solution have obtained very discordant results, according 
to the method they employed. 
Winkelblech,* for instance, from his work on the rate of catalysis of 
methyl acetate by ortho-amidobenzoic acid hydrochloride at 25° C., estimates 
the hydrolysis constant ^ at 120. 
From the electrical conductivity of the same solution at ^ = 16 he gives 
the value 180 for 
The calculation of the hydrolysis constant in these two cases rests on 
quite a different basis. The rate of catalysis depends simply on the con- 
centration of hydrion in the solution, and therefore should give as directly 
as possible the amount of free acid present, and so the hydrolysis. 
The conductivity of the solution, on the other hand, is the sum of the 
molecular conductivities of all the substances present. It depends, therefore, 
on various factors, any of which may conceivably exert a disturbing 
influence on the others. 
There are present in the solution — 
(1) The Salt, of the general formula HRC1, probably largely dissociated 
into its ions, HR and Cl. 
(2) Hydrochloric acid, formed by the hydrolytic action of waf er, and 
also highly ionised. 
(3) The amphoteric base HROH, equivalent in amount to the free acid. 
It probably contributes but little to the total conductivity, as it is only 
slightly dissociated. 
(4) Water practically un-ionised. 
It was thought, in view of these results, that some effort should be 
made to find out what values are given by methods independent of these, 
in order to be in a position to judge which of the original methods is at 
fault, and, if possible, for what reason. 
* Zeitschrift fur Physikal. Chem ., vol. xxxvi. p. 546. 
