opP


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they go to Battel, or undertake any Affair that requires
Vigour and Force.
opium flops, for a time, all Overfiowings of Humours,
Fluxes, Hemorrhages, Eic. probably from the fmooth-
nefs and roundnefs of its Parts, which by a kind of Ti-
tillation, oblige the Inteflines, and other Vefels to con-
tra, themfelves. SeeOPIATES.
Willis, Sylvigs, and Muller look on Opinm as a coagulating
Poifon, which fixes the Spirits in the Nerves. Wepfer and
Pitcairn, on the contrary, maintain it to be a hot ditfolving
Poifon, which fubtilizes the Blood, exalts and reduces it'
into Vapours, which bloat up the Arteries; and the
bloated Arteries comprefling the Veins and Nerves, lhut
up the Paffage of the Spirits. See POISON.
By Analyfis, it is found to contain a great deal of vola-
tile Salt.
The Word is form'd from the Greek o76;, Juice.
OPOBALSAMUM, in Pharmacy, a whitifh Juice,Gum,
or Refin, diftilling from the Branches of a Tree call'd
Balfamum, or the Balm-Tree. See BALM.
'Tis whitilh, pretty thick, tranfparent, of a Smell ap-
proaching Turpentine, but much more agreeable.
'Tis the fame with the celebrated Balfamum verum, or
Balm of the Levant; at leaft the difference is not vifible,
nor can Authors fix it. See BALM.
It obtains a Place among the Alexipharmics, and is a
good Ingredient in the Tberiaca Andromachi, and Mithri-
date ; very ill fupply'd with the expreffed Oil of Mace
for a Succedaneum, which does not at all come up to the
fubtilty and alivity of its Parts, but is of a much heavier
Texture.
This, as all other Balfams, is Suppurative, Deterfive,
and Incarnating, apply'd outwardly to Tumors, Ulcers, or
green Wounds. See BALSAM.
OPOPANAX, or OPOPONAX, in Pharmacy, a Gum,
yellow without-fide, white within, fat, brittle, of an agree-
able Tafle, and a very fIrong Smell. See GUM.
The Latins call it Panaces Herculeunm, from Hercules, who
is fuppos'd to have invented it, or rather who firft difco-
ver'd its fpecific Virtues. 'Tis one of the three celebrated
Panacea, or univerfal Medicines, they attributed fuch
wonderful Virtues to. The two others are the .Afclepium
and Cbironium; the firft found by Efculapius, the fecond by
Cbiron. See PANACEA.
The Gum Opoponax flows by Inciflon from a Plant grow-
ing abundantly in Acbaia, Beotia, Tbocis, and Macedonia:
while 'tis liquid, 'tis white; but as it dries and hardens, it
airumes a beautiful golden yellow.
There are three Kinds imported; that in Tears; that
in the Mafs; and that counterfeited, or flatted.
The firfi is the befi, and the fecond is the better, as it
has the more Tears; the third is a rank Sophiflication, and
good for little.
It is little ufed internally ; tho"Etmuller ranks it among
Cathartics. Its chief Ufe is in the Cure of Wounds;
whence it enters the Compofition of the ULnguentum Divi-
uum, with the Galbanum, .4mmoniac, and Bdellium.
The Word is form'd from the Greek ZxQ-, inice, and
mtvce, the Name of the Tree which yields it.
OPPILATION, in Medicine, the A&1 of obflruaing, or
flopping up the Duas, or Paffages of the Body, by evil or
peccant Humours. See OBSTRUCTION.
The Word is chiefly ufed for Obflructions of the lower
Belly.
Vifcid, heavy Foods, difficult of Digeflion, are oppila-
tive; don't pafs off well, but flop in the Mouths of the
Veffels.
OPPONENT, a Perfon who withflands, or oppofes an-
other. See OPPOSITION.
The Term is chiefly ufed in fpeaking of Scholaflic or
Academic Difputes or Exercifes, where a Perfon who op-
pores a Thefis, or impugns it by his Objedions, is call'd
Opponens, Opponent.
OPPOSITES, Oppofita, fimply, among Logicians, are fuch
Things as differ among themfelves; fo, as not to differ in
like manner with fome third. By which Circumflance,
Oppofites differ from Difparates.
The Sghoolmen reckon four Kinds of Oppoftes; viz. rela-
tively, contrarily, priovatvely, and contradierily Oppofites. For
either, fay they, the Oppofition is between Ens and Ens,
or between Ens and Non Ens: If the former, it is either
with a dependent Ens, which makes a relative Oppofition,
the loweaf of all; or an independent one, which is a con-
trary one: If with a Non Ens, it is either with a Non Ens
fecundum quid, which is privative; or with a Non Ens fim-
ply, which is the higheft Oppofition. See RELATIVE,
CONTRARY, PRIVATIVE, and CONTRADICTORY.
OPPOSITES, Oppfita, complexly, are Propofitions that
clafh with each other: As, Man is an Animal; and Man
is not an Animal. See OPPOSITION.
OPPOSITE Angles. If a Line ST (Tab. GEOMETRY,
Fig.46.) meet two other Lines, A P and B R, in different


oPP


Points A and B, but in the fame Direftion; the Angles
X and y, as alfo z and j, hereby form'd, are cal'd oppjfite
Angles; particularly, a the external oppofite Angle, and z
the internal ppofite Angle of y.
OPPOsITE Cones, or a double Cone, two fimilar Cone,
vertically oppofite, and having the fame common Axis.
See CONE.
OPPOSITE SeFiont, are the two Hyperbola's bade by a
Plane cutting both thofe Cones.
If a Cone be cut by a Plane through its Vertex, and
afterwards by a fecond Plane parallel to the former ; this
latter Plane produced thro the oppofite Cone will there make
the oppofiteSeffions. See SECTIONS.
OPPOSITION, in Geometry, the Relation of two
Things, between which a Line may be drawn perpendicu-
lar to both.
OFPOSI TION, in Logic, a Quality of Difagreement, be-
tween Propofitions that have the fame Subjed, and the
fame Attribute. See PROPOSITION.
Oppofition, is faid by Logicians to be either Complex,
or lncomplex.
Incomplex, or Simple OPPOSITION, is the Difagreement of
two things, which will not fuffer each other to be in the
fame Subje&: Thus Heat is oppofed to Cold ; Sight to
Blindnefs, Fc. Which Oppfition has already been ob-
ferved to be offour Kinds. See OPPOsITE.
Complex OPPoSIrION, is defined by Arfioile to be the
affirming, and denying the fame Predicate of the fame
Subjea, not taken equivocally for the fame, according to
the fame, in the fame manner, and at the fame time: As
Socrates is learned; and Socrates is not learned.
The later Schoolmen, deviating from their Mailer, de-
fine Oppofition an Affecrion of the Enunciation, whereby two
abfolute Propofitions, the fame Extremes being fuppofed
in the fame Order, and Number, and underilood, without
any ambiguity, of the fame thing, oppofe each other, either
in refpea of Quantity, or of Quality; or of both.
According to the former Definition, there are three Spe-
cies of oppofition ; Contrary, Subcontrary, and ContradiAory,
According to the fecond, a fourth Species is admitted, viz.
Subaltern.
To know how and wherein, Propofitions are oppofite,
they mufi be compared in Quantity and Quality, all the
ways they can be compared in. If they be oppofite in
Quality and Quantity; I.e. if the one be Affirmative, and
the other Negative; the one Univerfal, the other Particu-
lar, they are faid to be contradiaory; v. gr. No Pleafure
is allow'd5 fome Pleafure is allowd. See CoNTRADIC-
TORY.
If they be only oppofite in Quality, and not in Quantity,
they are call'd Contraries, if Univerfal; and Sub-contraries,
if Particular; v. gr. All ufe of Wine is Evil ; no ufe of
Wine is Evil. Some Means of preferving Reputation are
allow'd 5 fome Means of preferving Reputation are not
allow'd. See CONTRARY, SC.
If the Propofitions be only oppofite in Quantity, they
are call'd Subalterns ; v. gr. Every Man is liable to Sin ;
foms Man is liable to Sin. But this laft is no proper Op-
fjition; inafmuch as the univerfal Propofition always in-
cludes the particularone.
Singular Propofitions, which can only be oppofed in Qua-
lity, are reducible to contradicaory ones.
The effential Properties of Propofitions confider'd with
regard to their Oppofition; are, I.That of two contradidlory
Propofitions, there is one always true, and another falfe.
2. Two contrary Propofitions can never be both true; but
may be both falfe, 3. Sub-contrary Propofitions may be
all true at the fame time ; as happens when the Attribute
is accidental to the Subjedc; but when it is effential to it,
the one is true, the other falfe. 4. Subalterns may be
either true or falfe at the fame time ; or the one may be
true, the other falfe. If the Attribute be effential to the
Subje&, the Subaltern Affirmatives are true, and the Ne-
gatives falfe ; but if the Negatives deny the Subjec& an
Attribute incompatible with theSubje&t, they will be both
true. When the Attribute is accidental to the Subjecl, the
univerfal Subaltern is ordinarily falfe, and the particularone
true.
OPPOSITION, in Rhetoric, a Figure, whereby two things
are alfembled together, which appeared incompatible 3 as
when Horace fays, a wife Folly.
In Boubours's Notion, this Figure, which feems to deny
what it eflabliffies, and contradicas itfelf in Appearance, is
very Elegant.
OPPOSITION, in Afironomy, is that Afpea, or Situation
of two Stars, or Planets, wherein they are diametrically
oppofite to each other, or x8o' a-part. See CONJUNC-
TION.
When the Moon is diametrically oppofite to the Sun, fo
that lhe 1hews her whole illumined Face; The isfaid, with
regard to the Sun, to be in Obpofition ; and The is then faid
tobe in her Ful, and Ihines all Night long. Sec: PUASIS.
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