C H E M : 
advances i a brown mafs, confiderably refembling a re¬ 
fin, remains in the retort. 
The acetic ether mull be rectified by a gentle heat with 
potalh. This ether has a very agreeable fmell, peculiar 
to itlelf; it neither reddens nor greens the blue vegeta¬ 
ble colours ; it rather makes paper Itained with turnfole 
darker. Poured on the back of the hand, it evaporates 
inftantly, leaving no humidity on the (kin, but a degree 
of foftnefs. In a long narrow bottle with an equal quan¬ 
tity of water, it will fwim on the furface in the propor¬ 
tion of four fevenths; that is to fay, three fevenths of its 
volume combine with the water, and difappear. This 
ether lofes none.of its properties by age. 
The acetous acid, or common vinegar, affifted by heat, 
difl'olves the precipitate of gold made from oxygenated 
muriatic acid by adding a fixed alkali. This acetous l'o- 
lution of gold precipitated by ammoniac affords fulmi¬ 
nating gold, as Bergman has fhewn. Vinegar does not 
aft on platina or filver while they are in the metallic 
ftate, but it diffolves their oxyds. 
Vinegar combines with many of the immediate princi¬ 
ples of vegetables. It diffolves extrafts, mucilages, and 
effential falts; unites with aroma, and is confidered as 
the proper folvent of gum refins. It has even, after a 
certain length of time in the way of diflillation, a con- 
fiderable aftion on fat oils, which it converts into a fa- 
ponaceousflate. But the combination of vinegarwith vege¬ 
table fubftances has been by no means accurately examined 
This acid is ufed to extraft fome of the vegetable prin¬ 
ciples, more efpecially that of fmell ; and vinegars of dif¬ 
ferent nature, either fnnple or compound, are prepared 
for medical ufe. The vinegars of fquills, colchicum, &c. 
afford an example of the firfl j the theriacal vinegar, and 
the vinegar of the four thieves, are of the fecond kind. 
Thefe medicines are prepared by maceration and digef- 
tion continued for feveral days. As the acid is volatile, 
it is dillilled from aromatie plants, whofe odorant prin¬ 
ciple it takes up ; the dillilled vinegar of lavender, uted 
as a perfume, is of this kind ; thefe liquors are in general 
lefs agreeable than fpirituous dillilled waters. 
Vinegar is much ufed, as to feafon food. It is likewife 
of excellent ufe in medicine, as a refrefhing and antifep- 
tic fluid. A fyrup is made with fugar, which is' given 
with great fuccefs in burning or putrid fevers, &c, This 
acid, externally applied, is allringent and bracing. All 
its combinations are likewife applied to medical ufes. 
The acetit of potafh and of foda, which are known by 
the names of terra foliata tartari , and mineral acetous fait, 
are powerful deobftruent and aperient remedies; they 
are adminiflered in the dole of from half a drachm to a 
drachm. The fpirit of Mindererus, or folution of am- 
moniacal acetit, taken in the dofe of a few drops in a 
proper liquid, is aperient, diuretic, cordial, antifeptic, 
&c. It often fucceeds in the leucophlegmatia, or fwell- 
ing of the external parts of the body. The acetit of 
mercury, or mercurial terra foliata, is an excellent anti- 
venerea! ; it is the principal ingredient in Keyfer’s pills. 
The extraft of Saturn, vinegar of Saturn, and the ve- 
geto-mineral water, are applied externally as deficcatives. 
Thefe medicines, being ftrongly repellent, ought to be 
adminiflered with great caution, efpecially when applied 
to parts which are ulcerated or without fkin. Boerhaave 
mentions feveral young women attacked with confump- 
tions, in confequence of the external ufe of preparations 
of lead. 
Cerufe enters into the compofltion of drying unguents 
and plallers, and verdigris is a component part of leveral 
collyria and unguents. Acetic acid, or radical vinegar, 
is ufed as a very powerful flimulant to be refpired by 
fuch as fall into fainting fits. For the convenient ufe of this 
remedy, a certain quantity is poured on fulphat of pot- 
a(h grofsly powdered, which is kept in a well-clofed bot¬ 
tle; this medicine is univerfally known by the name of 
fait of vinegar. Acetic ether has not yet been applied to 
S T R Y, 355 
any ufe ; neither is it known whether it has any peculiar 
virtues, differing from thole of other ethers. 
PUTRID FERMENTATION of VEGETABLES. 
All the vegetable fubftances, which have puffed the vi¬ 
nous and acid fermentation, are fufceptible of a third in¬ 
teftine commotion, by which they are changed; this is 
called the putrid fermentation. Stahl, and feveral other 
chemids, have thought, that this kind of fermentation 
is merely a confequence of the two preceding, or rather 
that thefe three phenomena depend on a fingle procefs, 
or motion, which tends to deftroy the texture of folid 
fubftances, and to change the properties of fluids. It is 
true, in faft, that if certain vegetable fubftances be left 
to themfelves, they pals through the three fermentations 
fuccelfively, and without interruption. For example; 
all faccharine matters, dilfolved in a certain quantity of 
water, and expofed to a degree of heat of about fixty or 
eighty degrees, afford, firfl wine, afterwards vinegar, 
and at lafl the acid charafter is deftroyed ; they putrify, 
lofe all their volatile principles, and become dry, infipid, 
and earthy. But it mult be obferved, that a great num¬ 
ber of vegetable fubftances do not pafs through thefe 
three kinds of fermentation, at leaft as far as lenfe can 
diflinguifli. Infipid mucilages, and folutions of gum in 
water, become four, without exhibiting any appearance 
of wine; and the glutinous matter appears to pafs im¬ 
mediately to putrefaftion, without previoufly becoming 
acid. It therefore appears, that though thefe three fer • 
mentations fucceed each other in many of the vegetable 
principles, there are, neverthelefs, many others which 
are capable of the two laft, without the foregoing, or 
even of putrefying, without exhibiting previous figns 
of acidity. Thefe lafl participate of the nature of ani¬ 
mal fubftances, and afford ammoniac by the aftion of 
heat, and azotic gas by the nitric acid. It appears to be 
from this charafter, that the vegeto-animal fubftances 
putrify fo readily. 
The inteftine motion which changes the nature of ve¬ 
getable matters, and reduces them to their elements, re¬ 
quires the following conditions. Humidity, or the pre¬ 
fence of water, is one of the moll necefiary; dry and fo¬ 
lid vegetables, fuch as wood, are not at all changed, 
while they remain in that ftate ; but if they be moilten- 
ed, and their fibres feparated, the inteftine motion foon 
commences : water, therefore, appears to be one of the 
caufes of putrefaftion; and we fhall fee, in the animal 
kingdom, that the decompofition of this liquid appears 
to produce fermentation. Heat is" not lefs necefiary,. 
Cold, or the temperature of ice, not only oppofes this 
fpontaneous deftruftion, but retards its progreis, and in 
fome meafure reftores the former ftate of fubftances which 
have begun to change. The degree of heat necefiary to 
putrefaftion, is much lefs than that which maintains the 
vinous and acid fermentation, fince it require no more 
than about forty-five degrees of temperature ; but a 
ftronger degree of heat is more favourable to this pro¬ 
cefs, provided it be not lb ftrong as to volatilize all the 
humidity, and entirely to dry the fubftances which it 
putrefies. Accels of air is a circumftance which Angu¬ 
larly promotes putrefaftion, lince vegetable lubftances 
are very well preferved in a vacuum. This prelervation, 
however, has its limits; and the contaft of air does not 
appear to be indifpenfable for carrying on putrefaftion, 
like the two conditions before mentioned. 
The putrefaftion of vetables has its peculiar pheno¬ 
mena. Vegetable fluids, which putrefy, become turbid, 
loie their colour, and depolit different fedinients; bub¬ 
bles rife to the furface, and mouldinels appears at the 
beginning. Vegetable matters, Amply moiftened, and 
foft, exhibit the fame phenomena ; the commotion is 
never fo great as in the vinous and acetous fermenta¬ 
tions. The bulk of the matter which putrefies does not. 
appear to increafe, neither does its temperature rile; 
