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PREPARATION OF E\THER. 
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 in the main reaction, the formation of sul- 
phurie 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 nas 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 reaciion cannot be the inhibiting fac- 
tor, for it has been learned that it is practicable 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 conditions 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. 
