Phelps and Eddy — Ester Formation. 299 



bismuth and antimony chlorides with the hydrochloric acid in 

 the concentration taken did not give a clear solution in any 

 case, as is also true of all the other chlorides employed as cata- 

 lyzers. In interpreting the results given in the tables some 

 slight account should be taken of the fact of the insolubility 

 of the salts used, especially where the amount is large. This is 

 obvious when it is considered that a homogenous mixture 

 could not be maintained by the agitation of the liquid as caused 

 by the bubbling of the alcoholic mixture through the mass in 

 the esteritication flask. 



The action of the catalyzers can be seen by comparing with 

 each other the experiments given in Tables I and II. Evi- 

 dently zinc chloride present in the larger amount as a second 

 catalyzer with the small per cent of hydrochloric acid causes 

 the esterification of benzoic acid with ethyl alcohol in largest 

 amounts although copper or tin chloride present in molecular 

 ratio for chlorine content are almost equally good. The pres- 

 ence of more than two grams of water of crystallization with 

 the copper chloride in experiments (21) of Table I would 

 appear to have produced no noticeable reduction in the amount 

 of ester produced by the anhydrous salt taken in experiment 

 (20) of Table I, where the yield is only 0*9 per cent better, 

 although the time of action is decidedly longer. The chlorides 

 of bismuth, antimony, and mercury in the higher condition of 

 oxidation seem to be about equally efficient as catalytic agents. 

 They are nearly as effective in their action as either zinc, 

 copper, or tin chloride. Calcium chloride present in the 

 smaller amount seems to be without effect, as is seen when 

 experiment (3) of Table I is compared with experiment (3) of 

 Table II. In larger amount it hinders esterification to a 

 marked degree. Strontium chloride in the amounts taken 

 seems to hinder esterification but not to such an extent as did 

 the larger amount of calcium chloride. Barium chloride seems 

 to hinder esterification slightly. The chlorides of lead, mer- 

 cury in the lower condition of oxidation, manganese, and potas- 

 sium at least do not assist esterification if their action is not 

 entirely without effect. It was noticed that from the mercur- 

 ous chloride small amounts of mercury distilled into the con- 

 denser, indicating decomposition of the mercurous chloride 

 under the conditions of esterification. Sodium chloride appears 

 to hinder esterification slightly, lithium chloride hinders more, 

 ammonium chloride still more, and aluminium chloride more 

 than any of the chlorides studied here except calcium when 

 present in the larger amount. 



It is worthy of note that each chloride, and, moreover, dif- 

 ferent amounts of the same chloride, tend to show an individual 

 and characteristic effect as a catalytic agent with a small amount 



