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PREPAEATIOlSr OF EtHEE. 



By p. N. Evans. 



It is commonly stated that in the preparation of ether by running alco- 

 hol into sulphuric acid kept at about 140 deg. Centigrade, while the opera- 

 tion is nominally a continuous one, the acid acting catalytically, the volume 

 of ether obtainable amounts to only about six times that of the acid used 

 before the action is seriously impaired, soon to cease altogether. 



Various causes for this limitation have been suggested, including the 

 accumulation of water formed iu the main veactioii, the formation of sul- 

 phuric and sulphonic esters rendering the acid unavailable, and the actual 

 destruction of the acid by reduction to sulphurous acid by the organic com- 

 pounds present. Little or no experimental evidence is given in support of 

 any of these hypotheses, and the present difference of opinion leaves the 

 question still open. 



With the assistance of Miss Lena Sutton the writer is attempting to 

 get more definite information as to the actual limits of the reaction and 

 their cause or causes. At the time of writing the work has not proceeded 

 far enough to provide the solution of the problem, but it has already been 

 learned that instead of the efficient limit being reached when the volume of 

 the ether amounts to about six times that of the acid used there is no dim- 

 inution of efficiency at about fifty times the volume, when ordinary com- 

 mercial alcohol and acid are employed. It has been found, too, that the 

 accumulation of water formed in the reaction cannot be the inhibiting fac- 

 tor, for it has been learned that it is practical^le to start with highly di- 

 luted acid and obtain the usual results, the acid evidently becoming con- 

 centrated to the necessary degree by loss of water at the temperature 

 ordinarily employed 



In order to determine the proportions of ether, alcohol and water in 

 the successive distillates, they are submitted to fractional distillation, and 

 the results compared with those from known mixtures in the proportions 

 possible under the coiiclitions of the experiment, assuming the alcohol used 

 to have undergone the reaction with varying degrees of completeness. 



It is hoped to obtain further experimental evidence bearing upon the 

 problem during the present academic year. 



