108 On the Cultivation of the Vine , 
because it is founded not on hypothesis but on the nature 
of things. 
In cold countries, where the grapes are very aqueous 
and little saccharine, they ferment with difficulty : fer- 
mentation in that case may be excited by two or three 
principal means : 
1st, By the help of a funnel of tin plate with a very 
wide tube, which descends to within four inches of the 
bottom of the vat, and through which boiling must is in- 
troduced into it. Two pailfuls may be used for 300 bot- 
tles of must. This process proposed by Maupin, has 
produced good effects. 
Sd, By shaking the vintage from time to time : this 
motion is attended with this advantage, that it renews the 
fermentation when it has ceased or become weak, and 
causes it to be uniform throughout the mass. 
3d, By laying a covering not only over the vintage, but 
round about the vat. 
4th, By heating the atmosphere of the place in which 
the vat stands. 
It often happens that the working of the vintage slack- 
ens, or that the heat is unequal through the mass : it is 
to obviate these inconveniences, especially in cold coun- 
tries, where they are more frequent, that the vintage is 
from time to time trod upon. Grentil made two vatfuls 
of eighteen butts each, and with grapes from the same 
vines, and collected at the same time : the grapes were 
freed from the skins, stalks, &c. and bruised ; the juice 
of both was perfectly equal in quality, and the vintage 
was put into vats of equal size : the weather, but parti- 
cularly in the morning and at night, was exceedingly 
cold. 
At the end of some days the fermentation began : it 
was observed that the centre of the vats was exceedingly 
warm and the edges very cold ; the vats were so close as 
