106 CELLAKING. 



Wines which can be cellared are those which im- 

 prove, or to speak more correctly, those wines are stored 

 which do improve with age. In these, odoriferous sub- 

 stances are formed, the wine becomes less acid and 

 better tasted; such as is coloured often deposits a 

 considerable amount of sediment, and if the wine be 

 stored in casks, there is constant increase of alcohol. 



"We must begin by considering the change which 

 takes place in the wine. 



The ancients knew that wine improved if kept in 

 leathern bottles, and the same result is obtained by 

 keeping it in wooden vessels : for both leather and 

 wood are more easily penetrated by water than by 

 alcohol ; evaporation ensues from both, but more 

 freely from water, and the wine consequently becomes 

 richer in alcohol. Sommering's experiments rendered 

 this very intelligible ; since, by putting weak spirit into 

 a bladder, and hanging it in a warm place, he increased 

 its strength. Later observations have caused Som- 

 mering's result to be received with modification, so 

 that the simple evaporation of water is no longer 

 spoken of, since it has been ascertained that a certain 

 quantity of alcohol, though proportionately less, eva- 

 porates with the water. 



Even supposing equal quantities of alcohol and 

 water to be evaporated, the wine would still be im- 

 proved, as all the other constituents would remain 

 undiminished. But Graham* a short time since 



* Chem. Gaz. 1854, p. 420. 



