Page:Cyclopaedia, Chambers - Volume 2.djvu/624

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1'. The fame Piece of Matter or Subftance may happen to be a. Part of two or more Bodies.— Thus a Eifh feeding on a Man, and a Man afterwards feeding on the Fifh; Part of the Bo- dy of the firft Man becomes firft incorporated with the Eft. and afterwards in the Fifti, with the laft Man. Again, Iaftances have been known of one Man's feeding immedi- ately on another; and among the Cannibals of xheWefl Indies tits Pradice is frequent.

Now, where the Subftance of one is thus converted into the Subftance of another, each can't arife with his whole Body; and to which ihall the common Part be allotted?

To this Objection fome anfwer, that as all Matter is not fit or difpofed to be ailiroilated to the Body, and incorporated with it : Human Flelh may very probably be of this Kind, and therefore what is thus eaten, may be again excreted and carried off. — But Mr. Leibnitz's Anfwer feems the more folid. — All that is effential to the Body, he urges, is the original Stamen, which exifted in the Semen of the Father," nay, and on the footing of the mo- dern Theory of Generation, which exifted in the Semen of the firft Man. This we may conceive as the moil minute Speck or Point imaginable, and therefore not to be feparated, or tore a- iunder, and any Part of it united with the Stamen of any other Man. All this Bulk we fee in the Body, is only an Accretion to this original Stamen; an Addition of foreign Matter, of new Juices to the primary, folid Stamen. There is therefore no re- ciprocation of the proper Matter of the human Body. See Stamen, Solid, &c.

The fecond Objedion is this.— The human Body, we know by the late Difcoveries in the Animal OEconomy, is continually changing : A Man has not entirely the fame Body to Day as he had Yelterday ; and it is even computed, that in lefs than feven Years time, his whole Body undergoes a change, and not a Par- ticle of the fame Body remains.— Which of thefe many Bodies, then, which the fame Perfon has in the Courfe of his Life, is it that (hall life ? Or does all the Matter that has ever belong'd to him, rife again ? Or does only fome particular Syftem thereof ? Tn= Body, e. gr. he had at 20, at 30, or at 60 Years old ? If only this or that Body arife, how fhall it be rewarded or punifhed for what was done by the other ? With what Juftice does one Perfon fuller, &c, for another?

To this it may be anfwered, on Mr. Loch's Principles, that perfonal Identity, or the fameuefj of a rational Being, confifts in Self-confcioufneis ; in the Power of confidering it felf the fame thing in different Times and Places.— By this every one is to him- felf what he calls felf; without confidering whether that felf be continued in the fame or divers Subftances. So far reaches the Identity of that Perfon. 'Tis the fame felf now it was then; and 'twas by the fame felf which now refleds on an Action, that Adian was performed.

Now, 'tis this perfonal Identity is the Objed of Rewards and Punifhments, which we have obferved may exift in different Succeilions of Matter ; fo that to render the Rewards and Pu- nifhments juft and pertinent, nothing needs but that we rife again with fuch a Body as that we retain the Confcioufnefs of our paft Actions. See Identity.

RESUSCITATION. See Resurrection and Revivifi- cation.

RETAINER, or Reteiner, in Law. See Reteiner.

To Retain, fpoken of Mares, iignifies to hold, ;. e. to Con- ceive after Covering.

RETAINING-Ew, is the firft Fee given to a Serjeant or Counfcllor at Law, whereby to make him fure, that he fliall not be on the contrary Side. See Fee.

RETAIL, in Commerce, &c. the buying of Goods in the Great, or by Wholefale, and felling them out again in fmall Par- cels. — Qui rem integrum ententes, per minutiorcs earn partes diftrahe- bant. See Commerce.

RETALIATION, the Ad of returning like for like. See TaLionis Lex.

RETARDATION, in Phyficks, the Ad of retarding, that is, of delaying the Motion or Progrefs of a Body, or of diminifh- ing its Velocity. See Motion.

The Retardation of moving Bodies arifes from two gteat Caufes : The Refijieuce of the Medium, and ihcForce of Gravity.

The Retardation from the Refflence is frequently confounded with the Refiftence it felf; becaufe with reiped to the fame moving Body, they are in the fame Proportion. See Resis- tance.

With refped to different Bodies, however, the fame Refift- ence often generates different Retardations— For if Bodies of equal Bulk, but different Deniities, be moved through the fame Fluid, with equal Velocity, the Fluid will ad equally on each ; fo that they will have equal Refijlences, but different Retardatiotis. And the Retardations will be to each other as the Velocities which might be generated by the fame Forces in the Bodies propofed : That is, they are inverfely as the Quantities of Matter in the Bodies, or inverfely as the Deniities.

Suppofe, then. Bodies of equal Denfity, but of unequal Bulk, to move equally fall: through the fame Fluid ; the Refiftences in- creafe according to their Superficies, that is, as the Squares of their Diameters ; but the Quantities are increafed in Proportion to the Cubes of the Diameters : the Refiftences are the Quanti-

ties of Motion, the Retardations are the Celerities arifing from them; and dividing the Quantities of Motion, by the Quantities of Matter, you will have the Celerities ; therefore the Retarda- tions are diredly as the Squares of the Diameters, and inverfely as the Cubes of the Diameters, that is, inverfely, as the Diame- ters themfelves.

If the Bodies be equal, move equally fwift, and are of the fame Denfity, but moved through different Liquids ; their Retarda- tions are as the Denfities of thofe Fluids. See Fluid!

When Bodies equally denfe, and of Bulk equal, are carried through the fame Liquid with different Velocities, the Retarda- tions are as the Squares of the Velocities. See Density, &c.

The Retardation from Gravity is peculiar to Bodies projeded upwards — A Body thrown upwards is retarded after the fame Manner as a falling Body is accelerated; only in the one Cafe the Force of Gravity confpires with the Motion acquired ; and in the others ads contrary to it. See Acceleration.

As the Force of Gravity is uniform, the Retardation from that Caufe will be equal in equal times. See Gravity.

Hence, as 'tis the fame Force which generates Motion in the falling, and diminifhes it in the rifing Body, a Body riles till it has loft all its Motion ; which it does in the fame time wherein a Body falling would have acquired a Velocity equal to that where- with the Body was thrown up. See Projectile.

Thus alfo, a Body thrown up will rife to the fame Height from which falling it would acquire the Velocity wherewith it is thrown up : Therefore the Heights which Bodies thrown up with dirfe- rent Velocities can rife to, are to each other as the Squares of the Velocities. See Projectile and Descent.

Hence the Retardations of Motions may be compared toge- ther : For they are firft, as the Squares of the Velocities ; fecond- ly, as the Denfities of the Liquids, through which the Bodies are moved ; thirdly, inverfely as the Diameters of thofe Bodies ; latt- ly, inverfely, as the Denfities of the Bodies themfelves.

The Numbers in the Ratio compounded of thole Ratio's, ex- prefs the Proportion of the Retardations; multiplying the Square of the Velocity by the Denlity of the Liquid, 'and dividing the Produd by the Produd of the Diameter of the Body, multi- plied into its Denfity, and working thus for feveral Motions ; the Quotients of the Divifions will have the fame compound Ratio to one another.

General Laws of Retardation of Motion.

1°. If the Motion of a Body be uniformly retarded; that is, if its Celerity be diminifhed equally in equal Times, the Space it paffes over is one half of that it would pais over in the fame time by an uniform Motion.

2?. The Spaces defcribed in equal times by an uniformly re- tarded Motion; decreafe according to the uneven Nurnbet, t>, 7, 5, 3, e^-c. — See farther under Acceleration.

RETCHING, or Reaching, the Effort or Endeavour to Vomit. See Nausea and Vomiting.

RETE Mirabile, in Anatomy, a fmall Plexus, or Net-work of Veffels in the Brain. See Plexus and Brain.

It furrounds the Glandula Pituitaria, and is very confpicuous in Brutes, but either not exiftent in Man, or fo very minute that its Exiftence is fairly doubted.

Willis will have it to confift of Arteries, Veins, and Nerves; Vteujfens of Arteries only; and others, of Arteries and fmall Veins. —Vteujfens affetts, with many other Anatomifts, that there is no Retc Mirabile in Man, in the Horfe, Dog, drc. 'Tis found in the Calf, Sheep, Goat, &c.

It was firft obferved, and defcribed by Galen ; who upon find- ing it in fome Brutes, concluded it to be likewise in Man : but all we fee like it in Man, is, that on the Sides of the Pitui- tary Gland, where its Place fhould be, the Carotid Arteries make a double Flexure, in Form of w, before they penetrate the Dura Mattr.

The ufe of the Retc Mirabile, Galen takes to be for concod- ingand elaborating the animal Spirits; as that of the Epididymides is for elaborating the Seed. See Spirit and Seed.

Dr. Willis thinks, with more probability, it may fervc to bridle the too rapid Incurfions of the Blood into the Brain of thole Creatures whofe Head hangs down much; to feparare iome of the fuperfluous ferous Parts of the Blood, and fend them to the Salival Glands as the Blood enters the Brain ; and to obviate Obftru6tions which may happen in the Arteries.

Rete Penny, in antient Records, a cuftomary Due of one Pen- ny for every Perfon, to the Pa.-ifh-Prieft.

RETEINER, or Retainer, in Law, a Servant not menial nor Domeftic ; that is, not continually dwelling in the Houfe of his Lord or Mailer ; but only wearing his Livery, and attending on fpecial Occafions. See Servant.

This Livery was antiently given by gteat Men, and fiequentiy for the Maintenance of Quatrels ; whence it was juftly prohibit- ed by feveral Statutes; as, 1 Richard II. on Pain of Imprison- ment, and grievous Forfeiture to the King. See Livery, Yeo- man, ejyc.

It was further prohibited by other Statutes of the fucceeding

Kings, whereby the Delinquents were fubjecfed to make Ran"

fom at the King's Pleafuie ; and Knights and Efquires hereof du-

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