$56 
On the Cultivation of the Tine y 
heat, the disengagement of gas, the formation of alcohol* 
and the coloration of the liquor. 
I shall here speak of each of these phenomena, ac- 
cording to what we know of them with certainty from 
observation. 
1st, Production of Heat . — It sometimes happens in 
cold countries, but particularly when the temperature is 
above 55 degrees, that the liquor put into the vat experi- 
ences no fermentation, unless some means can be found 
to heat the mass. This may be done by introducing into 
it warm must, stirring the liquor strongly, heating the at- 
mosphere, or covering the vat with cloths. 
But as soon as the fermentation begins, the heat ac- 
quires intensity. Sometimes a few hours’ fermentation is 
sufficient to carry it to the highest degree. In general it 
is in the ratio of the swelling up of the mass $ it increases 
and decreases like it, as will be proved by the experi- 
ments which I shall subjoin to this article. 
The heat is not always equal throughout the whole 
mass ; it is often more intense towards the middle, espe- 
cially when the fermentation is not sufficiently tumultu- 
ous to mix and confound by violent movements all the 
parts of the mass : in that ease the vintage is trod again ; 
it is agitated from the circumference to the centre, and 
an equal temperature is established in every point. 
We may admit as incontestable truths : 1st, That, at 
an equal temperature, the greater the mass of the vintage 
the greater will be the effervescence, movement, and 
heat. 3d, That the effervescence, the movement, and 
heat, are greater in vintage where the juice of the grapes 
is accompanied with the pellicles, stones, stalks, &c. 
than in must separated from all these matters. 3d, That 
fermentation can produce from 5 9 to 9 5 degrees of heat : 
at least, I have seen it in activity between these two ex- 
tremes. 
