214 THE ART OP WINE MAKING. 



the profession, as the "bonnet of the vintage," 

 disengaging during the action, in great abundance, 

 the carbonic acid. The temperature is raised, 

 and the sweet flavour dissipated. The liquor 

 becomes gradually more vinous, assuming a 

 deeper colour and transparency, as the particles 

 on suspension are precipitated, and i< ke their ul- 

 timate position as lees, at the bottom of the ves- 

 sel. The boiling, which so agitated the mass, 

 becomes gradually tranquil, assuming its former 

 volume, the operation is accomplished. 



Let us in a few words define the circumstances 

 by which this is effected. They are condensed 

 within four simple causes, to wit: The production 

 of the heat; The disengaging of the carbonic acid 

 gas; The fermentation of alcohol; and The pro- 

 per colouring of the liquid mass. 



The production of Heat. 



THE action of fermentation constantly disen- 

 gages the latent heat, and causes a great eleva- 

 tion of temperature; but there are some cases in 

 which there is not an equilibrium through the 

 whole mass. The centre of the mash, on plung- 

 ing deep your thermometer, will often be found 

 much heated, whilst the sides and surface remain 

 cold. It will there become indispensable that 

 the evil should be rectified, and the operation of 

 the various phenomena be rendered equal, in 



