IMPROVEMENT IN PREPARING ETHER. gQl 



VII. 



Observations on Sulphuric Ether, and its Preparation; by 

 Mr* Boullay, Apothecary, of Par in*. 



Jl. HE use of sulphuric ether is at present very extensive, The malting of 

 and its consumption so great, that it has become a produce sulphuric ether 

 of the arts in the large way. Its preparation, though much proved, 

 simplified, still merits attention; and appears capable of 

 being improved, not only in respect to economy, but also as 

 to the purity of the product. 



In the formation of sulphuric ether, whether by the dis- The latter pro- 

 filiation of a simple mixture of concentrated sulphuric acid < lucts always 

 and alcohol, or the addition of fresh alcohol to the resi- nplyte ' 

 duutn, all the quantity obtained is not equally dulcified ; 

 and, in spite of careful rectifications, the last portions al- 

 ways retain a more or less unpleasant smell, that may be . 

 ascribed to some oil intimately united with it, which it is 

 very difficult to separate completely. 



According to the theory of Messrs. Fourcroy and Vau- Theory of tht 

 quelin, founded on their learned researches into the subject, ™he? IOD ° 

 the attraction of sulphuric acid for water, assisted by heat, 

 determines the transformation of alcohol into ether. x This 

 reaction of the principles of alcohol, exerted under the in- What injurious 

 fluen.ee of the sulphuric acid, precedes the carbonization of to lt * 

 the mixture, the formation of the oleum dulce, the extri- 

 cation of sulphuric acid, and the other phenomena of the 

 process carried to its end. We may even venture to say, 

 that ether is no longer formed, when these products appear; 

 and that what passes over after that time is only separated 

 the residuum, in which it was contained ready formed. It 

 would be an advantage therefore, to prevent, or at least re- This should b* 

 tard, the appearance of these products, which announce a P reveiUed » 

 complete decomposition of the alcohol; and, by adding at 

 a proper time fresh quantites of this liquid, to keep up 

 such proportions, that the etherification may go on much 

 )onger. For this it appears necessary, that the sulphuric 



* Annalcs de Chimie, vol. LXII, p. 242. 



acid 



