A C                               (2
The G4ermnan Dif'penfatorieq abound with medicated Vine-
bars, chiefly aim'd againif gefilential Difeafes: but they are
.not ufed among us.-The (college retains fome of 'em, as the
ietumn Tberiacale Norimbergenfe, but it is never prefcrib'd.
ACHAT, in ronr LaWv-Ffenci, 'fignifies a 'Contrad, or
dBargain
Brveyors were by AS of Parliament 36 Ed. III. ordain-
'ed to be thenceforth called Achators. See PuRVEYORS.
AGClE, or ACH, a painful Ailment in any part of the Bo-
dy. See PAIN, and DisEksE.
Achcs are either Scorbutick, Rheumatick, owing to vio-
lent Strains, or the like.
Bead-Acii. See HEAD-,Ac7, and CEPIIALALGY.
ACHERNER, or AC lARN ER, in Alironomy, a Conflel-
lation of the firn Magnitude in the Sign Tifies.-Its Longi-
tude, Latitude, &c. See under the Article PISCES.
ACHILLES, a Name which the Schools give to the
principal Argument alledg'd by each Secd of Philofophers
in their behalf. See SECT.
In this Senfe, we fay, this is his Achilles ; that is, his
Mailer-Proof: Alluding to the Strength and Importance of
Achilles among the Greeks.
Zeno's Argument againfl Motion, is peculiarly term'd an
Acbilles.-That Philofopher made a Comparifon between
the Swiftnefs of Achilles, and the Slownefs of a Tortoife;
whence he argu'd, that a flow Moveable that precedes a
fwift 6ne by ever fo fmall Diflance, will never be outrun by
it. See MOTION.
The antient Botanifis gave the Name Achilhea to feveral
Plants; one of which is Taid to be the fame with our Mil-
lefolium; and took its Name from Acbilles, who, having
been the Difciple of Chiron, firfc brought it into ufe for the
Cure of Wounds and Ulcers.
T'he T'ndon of ACMIILLES, Corda Achillis, is a large Ten-
don, form'd by the Union of the Tendons of the four Mufcles
of the Foot, called Extenfores. See TENDON, and FOOT.
It is fo called, becaufe the fatal Wound whereby Achilles
is faid to have been flain, was given there.
ACHILLEIS, or ACIILLEID, a celebrated Poem of Sta-
tins, wherein he propofed to deliver the whole Life and Ac-
tions of that Hero. See POEM.
It only takes in his Infancy, the Poet being prevented
from proceeding, by Death.
The Achilleid is of the Heroic or Epic Kind; but ex-
treniely faulty in the Plan, or Fable. See FABLE, Let.
'Tis a Point controverted among 'the Criticks, whether
the whole Life of a Hero, e.g. of Achilles, be a proper fub-
jea Matter of an Epic Poem. See EriC, and HEROIC.
ACHOR, ACHORV-S, in Medicine, the third Species or
Degree of a ginea, or Scald Head. See TINEA.
Acdores are a fort of fpreading Ulcers, which break the
Skin into a Number of little Holes, out of which oozes a
vifcid Humour.-Achores only differ from Favi in this, that
their Holes are fmaller.
ACHRONICAL, in Aflronomy, is applied to'theRifing of
a Star when the Sun fets ; or the Setting of a Star when the
Sun rifes. See RISING, and SETTING.
The Achronical Rifing of Mars, who is then found to be
nearer the Earth than the Sun, has been one great Occafion
of exploding the antient CPtolemaic Syflem, which places
the Sun in the Centre of the World, and Mars beyond the
Sun. See EARTH, MARS, SC.
The Achronical is one of the three Poetical Rifings and
Settings of the Stars. See POETICAL.
Trhe Word comes from the Greek a and Xeiv-, Time.
ACID, ACIDUM, any thing which affieds the Tongue
with a Senfe of Sharpnefs, and Seurnefs. See TASTE.
Acids are ufually divided into manifeft and dubious.
The Manifcj2 Acids, are thofe above defined, which im-
prefs the Idea fenfibly.-Such are Vinegar, and its Spirit ;
the Juices of Citrons, Oranges ; Spirit of Nitre, Spirit of
Alurnn, Spirit of Vitriol, Spirit of Sullphur per Camnpanam,
Spirit of Sea Salt, &c. See VINEGAR, NITRE, VITRIOL,
ALUMN, SULPItUR, Sc.
Dubious Acids, are thofe which do not retain enough of
the Acid Nature to give fenfible Marks thereof on theTafle,
but agree with the Manifift Acids in fome other Properties,
fafficient to refer 'em to the fame Clafs.-Hence it appears
that there are fome Charaaers of Acidity more general than
that of the fharp Tafle; tho 'tis that Taile is chiefly regard-
ed in the Denomination.
The great and general Criterion, then, of Acids, is, that
they make a violent Effervefcence, when mix'd with ano-
ther fort of Bodies, called Alkalies. See EFFERVESCENCE.
Yet is not this Property alone univerfally to be depended
on to determine a Body an Acid, without the joint Confi-
deration of the Tafle, and the Changes of Colour produ-
cible in other Bodies thereby. - To diflinguifh dubious
Acids- from Alcalies, mix 'em with a blue Tindure of Vio-
lets: If they turn it red, they are of the Acid Tribe * if
green, Alkaline. See AtJALY.    I
Acids are all of the Tribe of Salts ; and compofe a parti.
cular Specics thereof, called Acid Sal1s. See SALT.


2                        ACI
Add, that the Acid Salts are all found to be volatile; by
which they are diflinguifh'd from the reff, which are either
fix'd, or at leat have a urinous, inflead of an acid Taik,
See VOLATILE, Fix'D, and URINOUS.
Some late Chymical Philofophers have even made it very
probable, that 'tis the Acid is the faline Part or Principle in
all Salts.-They confider it as a fubtile, penetrating Sub-
flance, dififed thro' the feveral Parts of the Globe * which,
according to the different Matters it happens to be united
withal, produces dilferent Kinds of Bodies: If it meets a
foffil Oil, it converts it into Sulphur; if it be received into
the Lapis Calarius, it coagulates with it, and becomes
Alumn; with Iron it grows into green Vitriol; with Cop-
per, into blue Vitriol, Wc.
Of this Sentiment is Sir L Newt'on.-. In decompomnding
' Sulphur, fays that Author, we get an Acid Salt, of the
' fame Nature with Oil of Sulphur per Campaniam; which
' fame Acid abounding in the Bowels of the Earth, unites
' fometimes with Earth, and thus makes Alumn; fometimes
' with Earth and Metal, and makes Vitriol; and fometimes
' with Earth and Bitumen, and thus compounds Sulphur.'
Opticks.
In elTca, all our native Salts, tho without any Mixture
from Art, are yet found to be real Mixtures; and their Coin-
pofition and Decompofition is eafily made.-,' As many as they
are, they may be all reduced, according to M. Homberg,
' to three Kinds, viz. Salt-petre, Sea-Salt, and Vitriol,
' each whereof has its feveral Species. Of the Combina.-
' tion of thefe with different oily Matters, are all the other
' Salts produced. By the Analyfes we have made of 'em,
they all appear to be compofed of an aqueous, an ear-
thy, a fulphurous, and an acid Part; but the Acid we
' hold the pure Salt: This makes our Chymical Principle
Salt, the common Bafis of all Salts; and which, antece-
' dent to its Determination to any particular Species, appears
to be one fimilar, uniform Matter, tho never found alone,
but always accompany'd with fome fulphureous Mixture or
£ other; which determines it to fome one of the three forts
' of Foffil Salts abovemention'd.' Mem. de I'Acad. R. das
Sciences. An. 1708.  See PRINCIPLE.
The Acid, accompany'd with its detetmining Sulphur, ne-
ver becomes fenfible to us, except when lodg'd either natu-
rally in fome earthy Matter, or artificially in an aqueous
one.-In the firfi Cafe, it appears under the Form of a cry-
Pralliz'd Salt, as Salt-petre, Sea Salt, Eec. In the fecond,
it appears in form of an Acid Spirit; which, according to
the Determination of the Sulphur accompanying it, is either
Spirit of Nitre, or Spirit of Salt, or Spirit of Vitriol.
What is here fpoke of the three fimple fbffil Salts, may be
equally applied to all the compound Salts of Vegetables
and Animals, with this difference, that the latter have al-
ways a larger Proportion of the earthy Matter than the fim-
ple ones, when in form of a concrete Salt; and a larger
Proportion of the aqueous Matter, when in form of an acid
Spirit.-And hence we account for two important Phaxnome-
na; 10, That the acid Spirits of Animal and Fouil Salts,
are always weaker, and lefs penetrating, as well as lighter
in Weight, than thofe of the Foffil Salts : 20, That after
a vehement Diffillation, they leave a larger quantity of ear-
thy Matter behind them than the Poffil do.
The Salt naturally contain'd in Plants, may be confider'd
as a Mixture of Earth, Oil, a little Water, and an acid
Salt: This lafl Ingredient being feparated from the Plant
with a vehement Fire, fhoots into a new Salt, which fome-
times retains an acid Tafle, as in the Tartar of Wine;
fometimes it affumes a Sweetnefs, as in Sugar ; fomertimes
is bitter, as in Quinquina ; and fometimes almofl infipid, as
in Sage. This, M. Rlomberg calls the ceffntial Salt of the
Plant; which, by a gentle Diflillation, refolves into an infi-
pid Water, an acid Liquor, and a ruddy fetid one; con-
taining part of the acid Salt, and part of the fetid Oil of
the Plant: of the Combination of which, is compofed a
particular Kind of fetid Salt, fmelling like Urine, called
the Volatile Salt or Volatile Alcaly Salt of the Plant: And
the Caput Mortuum remaining, being reduc'd into Afhes, is
feparated by Lixiviation into one Part of fix'd Alcaly Salt,
and another of infipid Alcaline Earth.-Add, that the ef.
fential Salt always difrolves entirely in Water, even the ear-
thy Part join'd with it. But if the fame Salt have been
robb'd, by means of Fire, of a great part of its Acid; the ear-
thy Part will not wholly diffolve, but a Sediment of infipid
Earth, indiffoluble in Water, will be round at bottom ; to
which, if an acid Spirit be added, it then becomes entirely
diffoluble in Water: Whence it may be fairly concluded,
that the other Part of the Affies, before diffolved in the
Water, and which after Evaporation appears in form of a
fx'd lixivial Salt, was only diffolved by Virtue of the Acid
it contain'd; or as having retain'd enough of the Acid to ef-
fecS a Diffolution.
Again, when the Earth of the Plant, fatiated with its
Acid, becomes a cryflalliz'd Salt; no more of the fame Acid
can be introduc'd into it; whereas the lixivious Salt drawn
froul