ETHERS. 305 



The action of sulphuric acid upon alcohol is not quite so 

 simple as described above, in connection with the general 

 methods for obtaining ethers, where the final result only was 

 given. An intermediate product, known as ethyl-sulphuric acid 

 or sulphovinic acid, is formed, which, by acting upon another 

 molecule of alcohol, forms sulphuric acid and ether, which latter 

 is volatilized as soon as formed. The decomposition is shown 

 by the equations : 



C 2 H 5 HO + H 2 S0 4 = C 2 H 5 HSO 4 -f H 2 O. 



Alcohol. Sulphuric Ethyl-sulphuric Water, 



acid. acid. 



C 2 H 5 HS0 4 + C 2 H 5 HO = H 2 S0 4 + (C 2 H 6 ) 2 O. 



Ethyl->ulphuric Alcohol. Sulphuric Ether, 



acid. acid. 



The liberated sulphuric acid at once attacks another molecule 

 of alcohol, again forming ethyl-sulphuric acid, which is again 

 decomposed, etc. Theoretically, a given quantity of sulphuric 

 acid should therefore be capable of converting any quantity of 

 alcohol into ether ; practically, however, this is not the case, 

 because secondary reactions take place simultaneously, and be- 

 cause the water which is constantly formed does not all distil 

 with the ether, and therefore dilutes the acid to such an extent 

 that it no longer acts upon the alcohol. 



Ether thus obtained is not pure, but contains water, alcohol, 

 sulphurous and sulphuric acids, etc. ; it is purified by mixing it 

 with chloride and oxide of calcium, pouring off the clear liquid 

 and distilling it. 



Pure ether is a very mobile, colorless, highly volatile liquid, 

 of a refreshing, characteristic odor, a burning and sweetish 

 taste, and a neutral reaction ; it is soluble in alcohol, chloroform, 

 liquid hydrocarbons, fixed and volatile oils, and dissolves in 

 eight volumes of water. Specific gravity at is 0.720 ; boil- 

 ing-point 35. It is easily combustible and burns with a lumi- 

 nous flame. When inhaled, it causes intoxication and then loss 

 of consciousness and sensation. The great volatility and com- 

 bustibility of ether necessitate special care in the handling of 

 this substance near fire or light. 



Stronger ether, jEther fortior of the U. S. P., contains about 94 

 per cent, of pure ether and 6 per cent, of alcohol, with a little 

 water, while ether, (Ether of the U. S. P., contains 74 per cent, 

 of pure ether and 26 per cent, of alcohol, with some water. 



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