1 7 EE 
FEE 
720 
place in it, and the very same phenomena 
appear which distinguish the production of 
wine. The fermentation of wort then, is 
nothing but a particular case of the vinous 
fermentation. But wort does not ferment so 
'yell, nor so soon, nor does it produce nearly 
so great a quantity of good fermented liquor, 
as when yeast is added to it. The reason of 
which is, probably, that the fermentation 
does not commence till an acid is generated 
in the wort, and before that happens part of 
the saccharine contents are decomposed ; 
whereas the yeast adds an acid, or at least 
something equivalent to it, at once. 
Wort ferments in close vessels, as Mr. 
Collier ascertained by experiment, equally 
well as in the open air. The decomposition, 
therefore, is produced entirely by the sub- 
stances contained in the wort, without the 
addition of any thing from the air. The 
quantity of beer produced in close vessels is 
much greater than when the process takes 
place in the open air. The reason of which 
is, that in the open air the beer gradually 
evaporates during the fermentation. Thus 
Mr. Collier found that 1 1 quarts, 3| oz. fer- 
mented in open vessels, lost in 12 days 40 oz. 
whereas an equal weight, fermented' in close 
vessels, lost only 8 oz. in the same time. Yet 
the quality of the beer was the same in each ; 
for equal quantities of both, when distilled, 
yielded precisely the same portion of alcohol. 
During the fermentation a quantity of car- 
bonic acid gas is constantly disengaged, not 
in a state of purity, but containing, combined 
with it, a portion of tiie wort; and if this gas 
is made to pass through water, it will depose 
wort, which may be fermented in the usual 
manner. 
When beer is distilled, alcohol is obtained, 
and the residuum is an acid liquor, the nature 
of which is still unknown. The theory of 
beer is so obviously the same with that of 
wine, that it requires no additional explana- 
tion. 
Fermentation, acetous. If wine or 
beer is kept in a temperature between 70° 
and 90°, it gradually becomes thick, its tem- 
perature augments, filaments are seen mov- 
ing through it in every direction, and a kind 
of hissing noise may be distinguished. These 
intestine motions gradually disappear, the 
filaments attach themselves to the sides and 
bottom of the vessel, and the liquor becomes 
transparent. But it has now lost its former 
properties, and is converted into acetous 
acid. This intestine decomposition has been 
long distinguished by the name of acetous 
ferinentatiop, because its product is acetic 
acid. That this fermentation may take place, 
certain conditions must be attended to. The 
most important of these will appear from the 
following observations: 
1. Neither pure alcohol, nor alcohol di- 
luted with water, is susceptible ©f this 
change. The weaker the wine or the beer 
is on which the experiment is made, the more 
readily is it converted into vinegar; the 
stronger they are, they resist the change with 
i he greater obstinacy. But it results from 
the experiments of Beecher, that strong 
wines, when they are made to undergo the 
acetous fermentation, yield a much better 
and stronger vinegar than weak wines. 
Hence it follows that alcohol, though of itself 
jt refuses to undergo the change, yet when 
other bodies are present which readily fer- 
ment, ft is decomposed during the process, 
and contributes to the formation of the acetic 
acid. 
2. Wine, entirely deprived of extractive 
matter either by spontaneous deposition or 
by clarification, does not undergo the acetous 
fermentation, unless some mucilaginous mat- 
ter is mixed with it. Chaptal exposed old 
wine destitute of this matter, in open bottles, 
to the greatest summer-heat of Montpelier 
for 40 days, and vet it did not become sour; 
but upon adding some vine-leaves to the 
same wine, it became acid in a few days. 
3. Wine never becomes sour, provided it 
is completely deprived of all access to at- 
mospheric air. 'The reason is, that during 
the acetous fermentation, oxygen is absorbed 
from the atmosphere in abundance; and un- 
less that absorption can take place, no vinegar 
is ever formed. Hence the reason that wine 
or beer is more apt to become sour after the 
cork has been drawn, and still more apt when 
part has been poured out of the bottle. 
4. A pretty high temperature is necessary 
for the commencement of the acetous fer- 
mentation. Wine or beer (unless very weak) 
scarcely becomes sour under the temperature 
of 65° or 70°. T he fermentation is very apt 
to commence when the temperature suddenly 
rises. Hence wine and beer are more apt to 
become sour at certain seasons of the year 
than at others. 
5. When the acetous fermentation is com- 
pleted, the whole of the malic acid originally 
contained in the wine has disappeared as well 
as the alcohol. We must conclude, there- 
fore, that they have been both converted into 
acetic acid. Part of the extractive matter 
has also undergone the same change, and 
seems indeed to have been the substance 
that first began the absorption of oxygen. 
Part of it is deposited in the state of Hakes ; 
part remains in solution, and disposes the 
vinegar to decomposition. Vinegar also con- 
tains a little tartar, and probably also citric 
acid. Malic acid is also found in new vine- 
gar; a proof that this part of the wine is the 
last to undergo the acetous fermentation. 
6. Acetic acid is formed in many other 
cases of the decomposition of vegetables be- 
sides the acetous fermentation These have 
been pointed out with much ingenuity by 
Vauquelin and Fourcroy. They may be 
reduced under three heads: 1st. Vvhen 
sugar, gum, tartar, wood, &c. are distilled in 
a retort, or even burnt in the open fire, 
acetic acid separates in combination with an 
empyreumatic oil which distinguishes its 
odour. Hence it was mistaken for other 
acids, and distinguished by the names of py- 
romucous, pyrolignous, pyrotartarous acids, 
till its real nature was ascertained by these 
distinguished chemists. 2dly. When concen- 
trated sulphuric acid is poured upon the 
same vegetable bodies, they are decomposed 
in a very different manner, being converted 
into water, charcoal, and acetic acid. 3dly. 
Acetic acid is evolved in considerable quan- 
tity during the spontaneous decomposition 
of urine, and some other animal substances. 
Thus it appears, that the component parts of 
this important acid are extremely apt to com- 
bine together in those proportions which 
constitute it. 
Fermentation, putrid, as it has been 
termed by the old chemists, is that process 
which converts vegetable and animal matters 
FES 
into soil. It is, however, net fermentation, 
but a different process, wanting almost all 
the characteristics of fermentation, and there- 
fore will be treated separately under the ar- 
ticle Putrefaction. 
FERN. See Filix. 
FERRARI A, a genus of the triandria or- 
der, in the gynandria class of plants, and in 
the natural method ranking under the sixth 
order, ensala:. The spathic are unifiorous ; 
the petals six in number, and wavingly curl- 
ed;* the stigmata cuculiatcd or cowled; the 
capsule is trilocular, inferior. There are two 
species, natives of the Cape of Good Hope 
and Mexico. There is a great singularity m 
the root of one these species, that it vegetates 
only every other year, and sometimes every 
third year ; in the intermediate time it re- 
mains inactive, though very sound and good. 
FERRET, in zoology. See Mustela. 
FERRUGINOUS, any thing partaking of 
iron, or that fcontains particles of that metal. 
It is particularly applied to certain mineral 
springs, whose waters are impregnated with 
the particles of iron generally termed chqly- 
beats. See Mineral Waters. 
FERRY, is a liberty by prescription, or 
the king’s grant, to have a boat for passage 
upon a river, for carriage of horses and men, 
for reasonable toll. Savil, 11 & 14. The 
owner of a ferry cannot suppress that ferry, 
and put up a bridge in its place, without" a 
licence. Show. 243. 257. 
FERRUM. See Iron, Chemistry, &c. 
FERULA, fennel giant, a genus of the 
digynia order, in the pentandria class of 
plants, and in the natural method ranking 
under the 45th order, umbellate. The fruit 
is oval, compressed plane, with three striae on 
each side. There are nine species, all of 
them herbaceous perennials, rising from three 
to ten or twelve feet high, with yellow llowers. 
They are propagated by seeds", which should 
be sown in autumn, and when planted out, 
ought to be four or five feet distant from each 
other, or from any other plants ; for no other 
will thrive under their shade. The drug assa- 
fetida is obtained from a species of ferula, 
though not peculiarly ; being also produced 
by some other plants, hee Plate Nat. Hist, 
rig. 206. 
Ferula, in the antient Eastern church, 
signified a place separated from the church, 
wherein the audientes were kept, as not being 
allowed to enter the church; whence the 
name of the place, the persons therein being 
under penance or discipline. 'This word was 
sometimes used to denote the prelate’s crozier 
or stall'. 
FESSE, in heraldry, one of the nine ho- 
nourable ordinaries, consisting of a line drawn 
directly across the shield, from side to side, 
and containing the third part of it, between 
the honour-point and the nombril. 
hESTT dies, in Roman antiquity, certain 
days in (he year devoted to the honour of the 
gods. Numa, when he distributed the year 
into twelve months, divided the same into 
the dies festi, dies profesti, and dies intercisi. 
The festi were again divided into days of 
sacrifices, banquets, games, and ferix. 
The profesti were those days allowed to 
men for the administration of their affairs* 
whether of a public or private nature ; these 
were divided into fasti, comitiales, comperen- 
dini, stati, and prseliares. 
