338 E. W. Dean — Esters of Substituted Aliphatic Acids. 



II. Ethyl iso-butyrate decomposes more slowly than the ester 

 of the normal acid ; a difference in the same direction but of 

 greater magnitude occurs with the corresponding alpha hydroxy 

 esters. 



III. Ethyl beta-hydroxy-butyrate decomposes more Blowly than 

 the alpha ester. 



IV. Esters of the butyric acid series appear in general to de- 

 compose more slowly than propionates and acetates. 



V. The effect of the hydroxyl group upon the velocity of acid 

 hydrolysis is not an additive property. 



VI. The velocities of saponification, measured in centinormal 

 sodium hydroxide at zero degrees, vary in the following order 

 with the numerical values representing approximate ratios : 



Ethyl alpha hydroxy-butyrate ( 1 3-5), ethyl beta-hydroxy- 

 butyrate (4 , 5), ethyl alpha-hydroxy-iso-butyrate (3 - 4), ethyl buty- 

 rate (1'5) and ethyl iso-butyrate (TO). 



The author wishes to acknowledge his indebtedness to Pro- 

 fessors W. A. Drushel and E.. G. Van Name for the assistance 

 and advice they have so kindly given during these experiments. 



