256 Phelps and Eddy — Purification of Esters. 



and advantageously. It is easy to see, however, that the smaller 

 the amounts of free acid, the more completely can the total 

 amount of ester present be recovered. With such amounts of 

 unesteriiied acid as remain when organic acids are treated 

 with alcohol containing mineral acid, on a return condenser, 

 according to Fischer, the loss of ester might be considerable. 

 But with such amounts of free acid as are left when esters are 

 made in the special form of apparatus described in a former 

 paper, neutralizing in the manner given here with dry potas- 

 sium carbonate is easily done without loss of ester in consider- 

 able amount. This is obviously true, since in the mixtures 

 shown in this paper the esters contain acid impurities far in 

 excess of the amount that would be found when esterifying 

 under proper conditions for ideal yields. 



