764 ETHYL. 



ether till that of sulpho-vinic acid is considered, I shall at present 

 describe the process for ether. 



Ether is evolved when alcohol and oil of vitriol are heated 

 together, and may be obtained by mixing and distilling in a glass 

 retort equal weights of these materials, due attention being paid 

 to the condensation of the product, which is volatile, by keep- 

 ing the receiver very cold. But as the power of the acid to 

 decompose alcohol is not exhausted in this process, it is found 

 advantageous to make additions of alcohol to the remaining 

 acid, or to introduce the latter in a continued stream. The 

 following is a continuous process for ether, first proposed by M. 

 Mitscherlich, as it is given by M. Liebig. Alcohol is employed 

 of density 0.822, or of 90 per cent, which may be obtained by 

 digesting proof spirits upon an equal weight of well dried car- 

 bonate of potash (free from caustic potash), when two liquids 

 are formed, the upper alcohol of the strength mentioned, which 

 may be drawn off for use, and the lower, a solution of carbonate 

 of potash in water. Five parts, by weight, of this alcohol are 

 mixed with nine parts of oil of vitriol, in a copper or cast iron 

 vessel, surrounded by cold water, and the mixture afterwards 

 introduced into a tubulated glass retort, which the mixture 

 should fill one half, or even a little more. The distillation is 

 best conducted by the heat of a sand-pot, in which the retort 

 should not be deeply sunk, and commences at a gentle heat ; 

 when the temperature increases too briskly, the fire should be 

 withdrawn. A glass tube is fixed by a cork in the tubulure of 

 the retort, of which the extremity within the retort is drawn out 

 into a point, having an opening about one line in diameter, and 

 dips one inch in the liquid. Without the retort, the same tube 

 is bent at a right angle, and may extend horizontally for two or 

 three feet ; it communicates with a reservoir of alcohol by means 

 of a metallic tube and stop-cock, by which the flow of the alco- 

 hol is regulated. The latter should be supplied so as to keep 

 the liquid in the retort at its original level, at which a mark 

 should be placed for that purpose. To condense the ether 

 which distils over, the beak of the retort is connected with 

 Liebig's tube condenser, charged with the coldest water. A 

 leaden alembic is used when ether is prepared on a large 

 scale. It is said that when operation is well directed, nothing 

 is formed but ether and water ; the same sulphuric acid may 



