HEINRICH ROSE ON iETHERIFICATION. 379 



be perceived that the second, and especially the third product, 

 consisted of aather far more pure than is obtained in other 

 modes of preparing that substance. 



III. As the idea is so general, that aether is formed from a 

 mixture of alcohol and sulphuric acid only on boiling, and as 

 in the usual mode of distilling, hydrated, and not anhydrous 

 alcohol is employed, a new series of experiments were performed 

 with the former. 



A pound of alcohol of 90° Tralles, such as is usually employed 

 in the preparation of aether, was mixed in the cold with a pound 

 of the hydrate of sulphuric acid, and the mixture subjected to 

 distillation in a water-bath, as in the second series of experi- 

 ments. The results were : 



First product : 4 drs. 3G grs. ; spec. gr. 0*833. 

 Second product : 2 oz. 4 drs. 20 grs.; spec. gr. 0"787. 

 Third product '. 4 drs. 50 grs. ; spec, gr, 0*789. 

 Fourth product : 5 drs. 17 grs.; spec. gr. 0'789. 

 Fifth product. 



The first product consisted almost entirely of alcohol, as in- 

 dicated by the specific gravity. The succeeding ones contained 

 much aether, or consisted mostly of it. Free water also "was 

 evident in this case only in the fifth and last product, which 

 consisted of 1 drachm of liquid, of which only one fourth was 

 separated water. To distil this small quantity over, it was ne- 

 cessary to heat for more than five hours. 



The tether obtained from a mixture of sulphuric acid and al- 

 cohol, at the temperature of boiling water, is far more pure, as 

 may be anticipated, and is indicated by the specific gravities 

 of the products, when anhydrous, instead of h3'drated, alcohol 

 is employed. The aether obtained from hydrated alcohol in 

 this way contains more alcohol, because upon mixing hydrated 

 alcohol with sulphuric acid, less is converted into sulphovinic 

 acid, and more remains in a free state in the mixture, than 

 when absolute alcohol is used. According, however, to the 

 theory advanced in this memoir, only that portion of the coal- 

 hol can produce aether which has been converted into sulpho- 

 vinic acid, and this aether distils over when heated, in com- 

 pany with the free alcohol. 



The fact that aether is produced from a mixture of alcohol and 

 sulphuric acid even at the boiling-point of water, is indeed 

 highly important in the theory of the formation of sether, and 



