770 ETHYL. 



liquid with water, part of the ether separates in a free state, and 

 part remains in combination with the acid. 



The same compound, however, is obtained from the action of 

 sulphuric acid on alcohol, a chemical action which cannot yet be 

 said to be fully explained, although it has been the subject of 

 much research. There are two steps in this action : 1. the pro- 

 duction of sulphovinic acid, and 2. the liberation of ether. 



1. Formation of sulphovinic acid. Equal weights of strong 

 alcohol and oil of vitriol heated together to the boiling point 

 of the mixture, and saturated at that temperature with milk of 

 lime, give the sulphovinate of lime, or sulphate of ethyl and 

 lime, which is soluble and may be separated by nitration 

 from a considerable quantity of insoluble sulphate of lime, 

 which is always formed at the same time. It is observed 

 that the cooling and the dilution of the mixture of alcohol and 

 sulphuric acid, before saturation, diminishes the proportion of 

 sulphovinic acid, or of sulphovinate of lime formed, by causing a 

 reproduction of alcohol. Even when the sulphuric acid is in 

 great excess, a considerable proportion of alcohol, often nearly 

 the half of it, escapes decomposition, or is not found in the sul- 

 phovinic acid when neutralised. That the whole alcohol, how- 

 ever, is at first converted into sulphovinic acid appears from the 

 circumstance that the mixture is not decomposed by a current 

 of dry chlorine, no hydrochloric being formed, a property of 

 sulphovinates, which undergo no modification by the action of 

 chlorine, while free alcohol is immediately decomposed into hydro- 

 chloric acid and other chloruretted products. A mixture of 100 

 parts of oil of vitriol, 48 parts of alcohol, and 18.5 parts of water, 

 which contains the elements of 2 atoms of sulphuric acid, I 

 atom of ether, and 6 atoms of water, boils at 284 (140 cent.), 

 and is not affected by chlorine ; it may be represented as 

 (EO,S0 3 + HO,S0 3 ) + 5 HO. 



The protohydrate of sulphuric acid, diluted with 55 per cent, 

 of water, or HO,SO 3 -f3HO, does not decompose alcohol at the 

 ordinary temperature, but the reaction occurs when the mixture 

 is boiled. 



It is observed by Mitscherlich that in the formation of sul- 

 phovinic acid, there is only a feeble disengagement of heat. If 

 to two parts of alcohol, one part of sulphuric acid and then one 

 part of water be added, the temperature of the mixture rises to 

 518 (70 cent.) ; about half of the alcohol being converted into 



