the Man ufacturing of Verdigrise . 14S 
care to expose them as little as possible to the air, and 
not to compress them. One vat full of husks ought to 
fill two, and to occupy a double space after this opera- 
tion. In some manufactories the husks contained in a. 
vat are distributed into twenty or twenty-five earthen ves- 
sels or jars called oules , and which are generally sixteen 
inches in height, fourteen in diameter at the belly, and 
about twelve at the mouth. When the husks have been 
put into these vessels, they are covered by putting the 
lid merely on the opening without pressing it down. 
The covers are of straw, and made for that purpose. In 
this state the husks soon heat ; and this change may be 
known by thrusting the hand into them, and by the sour 
smell which they begin to exhale. The fermentation 
first takes place at the bottom of the vessel, and gradual- 
ly ascending extends itself to the whole mass. It pro- 
ceeds to 30 or 35 degrees of Reaumur. 
At the end of three or four days the heat decreases, 
and at length ceases entirely; and as the manufacturers 
apprehend the loss of a portion of the vinegar by the na- 
tural effect of a heat too much prolonged, they take care 
after three days fermentation to remove the husks from 
the fermenting vessels, in order that they may sooner 
cool. Those who employ vats remove them into jars, 
and those who use jars put them into others. Resides 
the loss of the acetous spirit, too great heat inclines the 
mass at the bottom of the vessel to become mouldy, which 
renders it unfit for making verdigrise. Some manufac- 
turers, to increase the effect of the husks, form them into 
heaps, which they besprinkle with generous wine before 
they bring them to ferment. 
The fermentation does not always take place at the 
same time, nor with the same energy. Sometimes it 
commences in twenty-four hours, and sometimes it has 
not begun at the end of three weeks. The heat some* 
Yol. ii: 
s 
