376 HEINRICH ROSE ON /ETHERIFICATION. 



contained less alcohol ; but only in the sixth product was there 

 so much water that it separated, and the quantity increased in 

 proportion as the distillation was continued. 



The first six products smelt but slightly of oil of wine ; but 

 the seventh contained a portion, and also smelt of sulphurous 

 acid. After the first seven products had been mixed together, 

 and the separated water removed, they had a specific gravity of 

 0-788. 



It is well known that iether is prepared, of late, in the most 

 advantageous manner, by allowing a small stream of alcohol to 

 flow constantly into a mixture of alcohol and the hydrate of sul- 

 phuric acid, and distilling oflf «ther in proportion as alcohol is 

 added*. It has been denied that the presence of sulphovinic 

 acid is of essential influence in the formation of aether, and as- 

 serted that it is not necessary that the formation of this acid 

 should precede that of Eether, because in the method of preparing 

 aether alluded to, the boiling mixture must be constantly at a 

 temperature of 140° cent., at which sulphovinic acid could not 

 exist. But at the point where the current of cold alcohol flows 

 into the boiling mixture, the temperature is under 140°. The 

 sulphovinic acid formed is decomposed it is true, in a very 

 short time, from its soon acquiring the temperature of the 

 boiling liquid. The preparation of aether, according to the 

 above method, consists therefore in a constant formation, and 

 continual decomposition of sulphovinic acid. It is a pretty ge- 

 nerally entertained opinion that the production of aether from a 

 mixture of alcohol and sulphuric acid, is solely effected by the 

 boiling of the mixture, which takes place at a high temperature, 

 about 140° cent. In many works on chemistry we meet with 

 the assertion that when a mixture of sulphuric acid and alcohol 

 are heated at a temperature, not high enough for it to boil, no 

 aether, but merely anhydrous alcohol, is obtained. 



Were this assertion correct, it would be an important objec- 

 tion to the hypothesis I have advanced ; for, according to that, 

 it would be somewhat difficult to explain the circumstance why 

 the oxide of aethyl is separated at a lower temperature, as a hy- 

 drate, and at a higher one in an anhydi'ous state. 



But this common opinion is founded on an error, which to 

 me is quite incomprehensible. yEther is obtained even fi'om a 

 mixture of the hydrate of sulphuric acid and anhydrous alcohol, 



* See Poggendorif's Annalen, vol. xx. p. 461. 



