CENANTH1C ETHER. 817 



SECTION XI. 



ETHEREAL OIL OF WINES. 



The characteristic odour of wine by which it is distinguished 

 from dilute alcohol, is due to a particular substance, possessing 

 the properties of an essential oil. This is common to all wines, 

 and is not to be confounded with the principle which is gene- 

 rally termed the flower, aroma or bouquet of individual wines, 

 which is not volatile, and appears to be different in diverse 

 kinds of wine and to be altogether wanting in many kinds. 



This oil is less volatile than alcohol, and a small quantity of 

 it is found in the still after the distillation of a large quantity of 

 wine. The same oily liquid is also obtained on distilling the 

 lees of wine, especially what is deposited at the bottom of the 

 tun after the fermentation has begun. It constitutes about 

 4uiu part of wines. This oil belongs to the class of compound 

 ethers, and contains a new acid, which has been named cenan- 

 thic acid,* in combination with ether ; the oil, therefore falls to 

 be named renanthic ether. 



(Enanthic ether, C 4 H 5 O,C 14 H 13 O 2 . The crude ether con- 

 tains a variable quantity of free acid in a state of mixture ; 

 being more volatile than the acid, the oil may be separated from 

 it by a simple distillation, collecting only the first fourth of the 

 product. To obtain it perfectly pure, it is preferable to agitate 

 the oil frequently with a hot solution of carbonate of soda, which 

 dissolves the free acid without altering the ether. The small 

 quantity of water and alcohol it retains may be withdrawn from 

 it by digestion with chloride of calcium. 



The ether purified in this manner, is very fluid, colourless 

 with the odour of wine extremely strong, and almost intoxicating 

 when closely inspired. Its taste is very strong and disa- 

 greeable. It dissolves easily in ether and in alcohol, even 

 when the latter is pretty dilute ; water does not sensibly dis- 

 solve it. Its density is 0.862, its volatility very feeble; it boils 

 between 437 and 446 (225 and 230 centig.) ; the density of 

 its vapour is by experiment 10508, by calculation 10476.9, its 

 combining measure 2 volumes. CEnanthic ether is instantly 



* From O'IVOQ wine, and av0of flower. 



2 H H 



