487 
tlie secoiid effect predotuinates over tlie fii-st and llie velocity coëffi- 
ciënt instead of decreasing, increases witli the concentration of 
sodium picrate. 
Moreover Walden has showii tfiat there are Iwo types of salts 
witli regard to tlieir effects' on tlie di-electric constant of the solvent. 
He has observed tiiat N(CH3)4C1 markedly increases the di-electric 
constant of the solvent whilst CH,NHjHCl atfects tliis constant to 
a very slight extent. It is qnite possible that even in aqueons solntion 
salts like potassimn oxalate, sodium acetate, etc. do not increase 
appreciably the ionising power of the solvent and the velocity of 
the reaction in its presence does not increase. In this way we can 
explain the negative effect of potassium oxalate and positive effect 
of sodium picrate on ester hydrolysis from the point of view of the 
change of the di-electric constant of the solvent due to the dissolution 
of electrolytes. 
S U M M A R ¥. 
a. The hydrolysis of methyl acetate was investigated in presence 
of oxalic acid and picric acid and sodium picrate. In the fortner case, 
the velocity coëfficiënt falls off, whilst in the case of picric acid, 
the velocity coetficient increases with the concentration of sodium 
picrate up to a certain extent and then decreases with the increase 
of the concentration of sodium picrate. 
b. An explanation of these results is suggested on the basis of the 
increase of the di-electric constant and ionising power of the solvent 
observed by Walden when salts are dissol ved in it. 
Chemical Laboratory Muir Central College, 
A llahaba.d, India . 
