110 CELLARING. 



deny that the wine being kept in bottles increases it. 

 Evaporation is very much hindered by the cork, even 

 when it is not covered with resin and sealing-wax. 

 The sugar which exists, for example, in red wine, 

 is in too insignificant a quantity to evolve alcohol 

 by means of fermentation ; and in old wine, the open- 

 ing of the bottle causes no escape of carbonic acid. 

 Therefore, the formation of alcohol in the bottles is 

 impossible. 



The simple explanation of our finding old wine rich 

 in alcohol is, that only the stronger wines can be pre- 

 served, and the weaker ones cannot resist the effects 

 of time. 



The colour of wine is materially affected by another 

 change which it undergoes when cellared (I am sup- 

 posing it to be in bottles). The colour of liqueur- 

 wines becomes darker, but such wines as are rich in 

 tannic acid, port, for example, deposit a sediment, and 

 become lighter. Bed-wines, which contain no large 

 amount of tannic acid, generally grow darker. The 

 details, which must be mentioned in order to ex- 

 plain this change, will be better understood when we 

 come to consider more particularly the colouring 

 matter of wine. With regard to the fact just men- 

 tioned, that wines which are not rich in tannic acid 

 acquire a darker colour, I will only observe that the 

 diminution of free acid in the wine (be it tartaric or 

 acetic) is always connected with this appearance, for 

 the red hue is the effect of free acid, and the de- 



