Page:Cyclopaedia, Chambers - Volume 2.djvu/395

 PER

PERMEABLE, denotes a Body confider'd as its Pores are capable of Jetting Come what pafs thro' 'em. See Pore.

PER MINIMA, in Medicine, denotes a perfect Mixture of the fmallett Particles of feveral Bodies, or Ingredients. See Mixture and Minima.

PERMUTATION, the Truck, or Exchange of one Thing for another. See Exchange.

The Commerce of the Ancients, was perform *d wholly by way of Permutation. See Commerce.

Permutation, in the Canon Law, a real and active Ex- change of two Benefices. See Benefices.

Permutation, is a Means of bringing Benefices into Commerce without Simony. See Simony.

The Conditions requir'd to a canonical (Permutation are ; i°. That there be Benefices permuted on either Side; tho* the Revenues be unequal; and in Cafe of Inequality, no Com- penfation to be made in Money j but only a Penfion charged on the bigger. z° That each of the Permutants quit his Benefice, and make a Procuration ad refignandum. 3° That the Permutation he followed by a Collation of the Ordina- ry. 4. That the Ordinary be inform 'd of the Caufe of the Permutation. 5 That thofe to whom the Prefentation or Election to the Benefices belongs, give their Confcnt; or in Cafeof their Refufal,that the Confent of the1)iocefan behad.

The chief Rules of Permutation are, that if one of the Compermutants cannot enjoy, he re-enters with full right in- to the Benefice he has quitted ; and that if he die 'ere he have accomplish 'd the Permutation on his Part by the taking of PottMlion, the Compermutant who hasaccompliih'd, retains both Benefices, un lei's they fall into the Regale.

Permutations of Quantities, in Algebra , the Changes, Alternations, or different Combinations of any Kumberof Quantities. See Combination and Change. PERMU-FJ'flONEJrcMdiaccnatus & Ecclefios eideman- nex# cum Ecckjia i$prebenda, is a Writ iffued to an Ordinary, commanding him to admit a Clerk to a Benefice upon Ex- change made with another. Reg. of Writs.

PER MY & PER TOUT, a joint Tenant is faid to be feiz'd of the Land he holds jointly per my £5? per tout, i. e. he js feiz'd by every Parcel, and by the whole, T'otum tenet, £5? nihil tenet, fc.tottim conjunBim & nihil fepamtim.'Sr -acton.

PERNANCY, in Law, the taking or receiving any Thing ; from the French Prendre, to take.

Tithes in Pernancy are Tithes taken in kind. See Tithes.

PERNIO, in Medicine, a Difeafe afflicting the Hands and Feet in Winter-time, popularly call'd a Kibe or Chilblain. See Chilblain.

The Parts affected fwell, inclining from a white to a blue- ifh Colour, itch and ake 5 yet, the Tumour vanifhes without any Exulceration, upon anointing the Part with Petrol.

PERNOR of Profits, he who takes, or receives the Pro- fits of any Thing 5 from the French Preneur, Taker.

PERONE, in Anatomy, a Bone of the Leg, more ufually caWd Fibula. See Fibula. Hence

PERONE US Jnticus, longus or primus, a Mufcle of the Leg, arifing flefhy and tendinous from the Head to the Mid- dle of the Perone; whence running as in a Pulley, thro' the Channel on the hind Part of the outer Ankle Bone, it is in- ferted into the Upper-end of the Bone of the Metatarfus, which joins the great Toe : The Office of this Mufcle is to draw the Foot upwards.

Peron^lus Pofiicus, brevis, or fecundus, a Mufcle fome- times alfo call'd Semifibul<sits, arifing flefhy and (harp in the Back-part of the Perone; whence, continuing down the Outer- fide of the Bone till below the Middle, it forms a fmooth, flrong, flat Tendon, which runs thro' the fame Channel at he Bottom of the Malleolus externtis, with the Longus, to he Out-fide of the Os Metatarfi of the little Toe; Its Office is to pull the Foot upwards.

PERORATION, in Rhetoric, the Epilogue, or Iaft Part of an Oration j wherein, what the Orator had infifled on thro' his whole Difcourfe is urg'd a-frefh, with greater Vehemence and Paffion : Thus gHiintilian. See Oration. The peroration confifls of two Parts, {.Recapitulation, where- in the Subflance of what is diffufed throughout the whole Speech, is collected briefly, and curforiiy 5 and fum'd up with new Force and Weight. See Recapitulation.

And, z. The Moving of tire PaJJicns • which is fo peculiar to the peroration, that the Matters of the Art call this Part Ce- des afecJuum. See Passions.

The Paffions to be rais'd in the Peroration are various, according to the various Kinds of Orations: In a Panegyric, Love, Admiration, Emulation, Joy, ££c. In an Invective, Hatred, Contempt, &c. In a Deliberation, Hope, Confi- dence or Fear.

The Qualities required in the Peroration are, that it be vehement and paflionate; and that it be fliort : Becaufe as Cicero obferves, Tears foon dry up.

The Peroration was Cicero's Matter-piece : Here that great Orator not only fet his Judges and Auditors on Fire but even feem'd to burn himfelf; especially when he was to raife Pity and Commiferation towards the accufed 5 where, as he himfelf tells us, he frequently iitt'd the Forum with Weeping

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PER

and Lamentation. He adds, that where there wore fcra-al Orators to fpeak for the fame Perfon, the •Peroration was always referv'd to Cicero 5 and fubjoins, that if he exccll'd herein, 'twas not owing to Genius, but to the Grief he him- felt fhew'd. This is abundantly evident in his Milonian 'Per. oration; where he Cays fed Jims Jit: neque enimpne Lacbry. mis jam loqui pojfum; & hie fe Lecrymis defendi vetat—saA in that for Rabirius Poflhamus: fed jam, queniam, ut fpero fidem qtiam potui, tibipfafiiti, Pofihmm, reddam etiam Lai crymas quas debeo - Jam tndicat tot bomimim flews quamfis earns tuts, $ me dolor debilitat, includitqne vecem.

PERPENDICULAR, in Geometry, a Line falling di- rectly on another Line, or fo as to make equal Angles on each Side 5 call'd alfo a normal Line. See Line.

Thus the Line IG. (Tab. Geometry Fig. 5 7.J is Perpendi- cnlar to the Line K H. i. e. makes right and equal Angles therewith :.

Prom the very Notion of 'Perpendiculars, it follows ; 1. That the Perpendicularity is mutual, i. e. if a Line as J G be Perpendicular to another, A B 5 that other, is alio 'Perpendicular to the firft.

1. That only one Perpendicular can be drawn from one Point in the fame Place.

3. That if a Perpendicular be continu'd thro' the Line it was drawn Perpendicularly to; the Continuation will alio be Perpendicular to the fame.

4.. That if there be two Points of a right Line, each of which is at an equal Diftance from two Points of another right Line ; that Line is Perpendicular to the other.

5. That a Line which is perpendicular to another, is alfo Perpendicular to all the Parallels of the other. See Pa- rallel.

6. That a Perpendicular Line is the fhorteft of all thofe which can be drawn from the fame Point to the fame right Line.

Hence the Diftance of a Point from a Line, is a right Line drawn from the Vdmtperpendicular to the Line or Plane 3 and hence the Altitude of a Figure is a Perpendicular let fall from the Vertex to the Bafe. See Distance.

T"o ereS a Perpendicular G Ion any given Point G, in a right Line ML; one Foot of the CompafTes being in G, with any Interval at Pleafure, cut off equal Parts on each Side G H and G K 3 from the Points K and H, with an Interval greater by half than K H ftrike two Arches interfering in 7j the right Line G 1 is Perpendicular to M L.

'Perpendiculars are beft defcrib'd in Praflice by means of a Square 3 one of whofe Legs is applied along that Line to, or from which the Perpendicular is to be let fall or rais'd. See Square.

Pb ereS a Perpendicular on the End of a given Line, fup- pofe at P 5 open your Cofnpaffes to any convenient Diflance, and feiting one Foot in C, defcribe the Arch R P S 5 lay a Ruler from S through C, it will find the Point if in the Aich, whence draw P R, which is Perpendicular to P M.

To let fall a Perpendicular on a given Line MP, from a given Point Lj fet one Foot of the CompafTes in L, and with the other crofs the given Line in the Points M and G. Then fetting the Compaffes in G and M, firike two Arches inter- fefling each other below in 8 : Then lay a Ruler from L to 8, and the Line K L delcrib'd thereby is the perpendicular requir'd.

Perpendicular to aParabola, is a right Line cut- ting the Parabola in the Point in which any other right Line touches it, and is alfo itfelf Perpendicular to that Tan- gent. See Parabola.

A Line is faid to be Perpendicular to a Plane, when it is Perpendicular to all the Lines it meets with 'in that Plane ; and a Plane is Perpendicular to another Plane, when a Line in one Plane is 'Perpendicular to the other Plane. See Plane.

PERPENDICULARITY of Plants, is a curious Pbmio- mencn, in Nat. Hiftory, firfr. obferv'd by M. 'Dodart, and publim'd in an exprefs Effay on the Affectation of Perpendi- cularity, obfervabte in the Stems or Stalks of all Plants; of the Roots of many, and even of the Branches as much aspofflble.

The Matter of Fail is, that tho' almoft all Plants rife a little crooked 5 yet, the Stems fhoot up perpen- dicularly, and the Roots fink down Perpendicularly : Even fuch as by the Declivity of the Soil come out inclin'd, or fuch as are diverted out of the Perpendicular by any violent Means; again ftreighten tbemfelves, and recover their Perpendiculari- ty, by making a'fecond and contrary Bend or Elbow, without rectifying the firft.

A common Eye looks on this Affectation without any Sur- prize 5 but a Man that knows what a Plant is, and how rbrm'd, finds it a Subject of Aftonilhment.

In effefl, each Seed contains a little Plant, already form'd, and needing nothing but to be unfolded: The little Plant has its little Root 3 and the Pulp, which is ufually feparated into two Lobes, is the Foundation of the firlt Food the Plantule draws, by its Root, when it begins to germinate. See Seep, Radicle, ifjC.

Now, if a Seed in the Earth, be fo difpofid, as that the

Root