300 Phelps and Eddy — Ester Formation. 



of hydrochloric acid in the formation of ethyl benzoic ester 

 from benzoic acid and ethyl alcohol. However, it seems to be 

 true that certain of the chlorides may be grouped according to 

 their behavior as catalytic agents here. Although from the 

 theoretical considerations some of the catalytic effects shown in 

 this paper might have been predicted, such as the accelerating 

 action of antimony and bismuth chlorides and the lack of 

 action of potassium chloride, certain of the other effects could 

 not, so far as we are aware, have been predicted. The action 

 of cupric and mercuric chlorides in producing large amounts 

 of ester or of lithium chloride in hindering esterification could 

 not have been predicted. Further, Claisen* in the study of 

 catalytic effects in the formation of acetals from aldehydes 

 and ketones, found that ammonium chloride was an efficient 

 catalytic agent and that the alkali chlorides were without 

 action. It becomes evident then that catalytic effects are not 

 only specific and individual for different chlorides and for 

 different amounts of this same chloride, but, also, each catalytic 

 agent gives a characteristic effect, either positive, negative, or 

 neutral, in each specific kind of chemical change. 



All of the results given here were obtained under conditions 

 of temperature ranging from 100 to 110°. What differences 

 may be found at other temperatures will be determined and 

 given later. It is obviously too early in the study of catalysis 

 to complete our imperfect theory for such effects as are shown 

 in the contribution to the study of catalysis given in this 

 paper. 



* Berichte, xl, 3903. 



