Page:Cyclopaedia, Chambers - Volume 2.djvu/317

 OPP

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OPP

they go to Battel, or undertake any Affair that requires Vigour and Force.

Opium flops, for a time, all Overflowings of Humours, Fluxes, Hemorrhages, £?c. probably from the fmooth- nefs and roundnefs of its Parts, which by a kind of Ti- tillation, oblige the Inteftines, and other Veffels to con- tract themfelves. See Opiates.

Willi;, Sylvius, and Muller look on Opium as a coagulating Poifon, which fixes the Spirits in the Nerves. Wepfer and Pitcairn, on the contrary, maintain it to be a hot diffolving 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, fhut up the Paffage of the Spirits. See Poison.

By Analyfis, it is found to contain a great deal of vola- tile Salt.

The Wordisform'd from the Greek mis, 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 whitiih, 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. SeeBALM.

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 activity 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-iide, white within, fat, brittle, df an agree- able Tafte, and a very flrong Smell. See Gum.

The Latins call it Pamces Herculeum, 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 Chiron. See Panacea.

The Gum Opoponax flows by Incifion from a Plant grow- ing abundantly in Achaia, Beotia, Phocis, and Macedonia : while 'tis liquid, 'tis white ; but as it dries and hardens, it affumes a beautiful golden yellow.

There are three Kinds imported ; that in Tears ; that in the Mafs; and that counterfeited, or flatted.

The firft is the beft, and the fecond is the better, as it has the more Tears ; the third is a rank Sophiftication, and good for little.

It is little ufed internally ; tho~£iM«l/er ranks it among Cathartics. Its chief Ufe is in the Cure of Wounds ; whence it enters the Competition of the Vnguentum Divi- Kum, with the Galbattum, Ammoniac, and Bdellium.

The Word is form'd from the Greek »»©-, Juice, and TOKt|, the Name of the Tree which yields it.

OPPILATION, in Medicine, the Afl of obftrufling, or flopping up the Ducts, or Paffages of the Body, by evil or peccant Humours. See Obstruction.

The Word is chiefly ufed for Obftruflions of the lower Belly.

Vifcid, heavy Foods, difficult of Digeflion, are oppM- itve ; don't pafs off well, but flop in the Mouths of the Veffels.

OPPONENT, a Perfon who withflands, or oppofcs an- other. See Opposition.

The Term is chiefly ufed in fpeaking of Scholaflic or Academic Difputes or Exercifes, where a Perfon who op- pofes a Thefis, or impugns it by his Objections, is call'd Opponent, Opponent.

OPFOSITES, Oppofita, [imply, among Logicians, are fuch Things as differ among themfelves ; fo, as not to differ in like manner with fome third. By which Circumflance, Of fofites differ from Difparates.

The Schoolmen reckon four Kinds of Oppofites; viz. rela- tively, contrarily, frivatively, and contradictorily 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 dependant Ens, which makes a relative Oppofition, the loweft 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 (im- ply, which is the higheft Oppofition. See Relative, Contrary, Privative, and Contradictory.

Opposites, Oppofita, 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.4<f.) meet two other Lines, A.P and BR, in different

Points A and B, but in the fame Direction ; the Angles « and y, as alfo zandjy, hereby form'd, are call'd oppofite Angles ; particularly, u the external oppofite Angle, and a the internal oppofite Angle of y.

Opposite Cones, or a double Cone, two fimilar Cones, vertically oppofite, and having the fame common Axis. See Cone.

Opposite SeBiorit, are the two Hyperbola's made by at Plane cutting both thofe Cones.

If a Cone be cat 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 oppofite Se&ions. See Sections.

OPPOSITION, in Geometry, the Relation of two Things, between which a Line may be drawn perpendicu- lar to both.

Opposition, in Logic, a Qualityof Difagrecment, be- tween Propofitions that have the fame Subject, and the fame Attribute. See Proposition.

Oppofition, is faid by Logicians to be either Complex, or Incomplex.

Incomplex, or Simple Opposition, isthcDifagreementof two things, which will not fuffcr each other to be in the fame Subjefl ; Thus Heat is oppofed to Cold ; Sight to Blindnefs, (Sc. Which Oppofition has already been ob- ferved to be of four Kinds. See Opposite.

Complex Opposition, is defined by Artflotle to be the affirming, and denying the fame Predicate of the fame Subject., not taken equivocally (or 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 Mafrer, de- fine Oppofition an Affection of the Enunciation, whereby two abfolute Propofitions, the fame Extremes being fuppofed in the fame Order, and Number, and underft'ood, without any ambiguity, of the fame thing, oppofe each other, either in refpecT : of Quantity, or of Quality; or of both.

According to the former Definition, there arc three Spe- cies of Oppofition ; Contrary, Subcontrary, and Contradictory : According to the fecond, a fourth Species is admitted, v'm. Subaltern.

To know how and wherein, Propofitions are oppofite, they muft 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 contradictory ; v. gr. No Pleafure isallow'd; fome Pleafure is allow d. See Contradic- tory.

If they be only oppofite in Quality, and not in Quantity, they are call'd Contraries, itXJniverhl; and Sub-contraries, if Particular ; v. gr. All ufe of Wine is Evil ; no ufe of Wine is Evil. Some Means of prcferving Reputation are allow'd ; fome Means of preferving Reputation are not allow'd. See Contrary, i£c.

If the Propofitions be only oppofite in Quantity, they are call'd Subalterns ; v. gr. Every Man is liable to Sin ; fome Man is liable to Sin. But this laft is no proper Op- ^■fition ; inafmuch as the univerfal Propofition always in- cludes the particular one.

Singular Propofitions, which can only be oppofed in Qua- lity, are reducible to contradictory ones.

The effential Properties of Propofitions confider'd with regard to their Oppofition ; are, I. That of two contradictory Propofitions, there is one always true, and another falfe. l. Two contrary Propofitions can never be both true ; but may be both falfe, ;• Sub-contrary Propofitions may be all true at the fame time ; as happens when the Attribute is accidental to the Subject ; 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 Subject, thefubaltern Affirmatives are true, and the Ne- gatives falfe ; but if the Negatives deny the Subject an Attribute incompatible with the Subject, they will be both true. When the Atttibute is accidental to the Subject, the univerfal Subaltern is ordinarily falfe, and the particular one true.

Opposition, in Rhetoric, a Figure, whereby two things are affembled together, which appeared incompatible; as

when Horace fays, awife Polly.

In Bouhours's Notion, this Figure, which feems to deny what it eftablifhes, and contradicts itfelf in Appearance, is very Elegant.

Opposition, in Aftronomy, is that Afpect, or Situation of two Stars, or Planets, wherein they are diametrically oppofite to each other, or 180 a-part. See Conjunc- tion. , c

When the Moon is diametrically oppofite to the Sun, io that fhe (hews her whole illumined Face ; (he isfaid, with regard to the Sun, to be in Oppofition ; and (lie is then faid to be in her pull, and fliines all Night long. See Fhasis.

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