Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/362

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Which the Italian journals mentioned, as the principal part of this difcovery, was no other than an artery fent off'from that of the capfula on each fide, to the tefticles of men, and ovaria of women. Morgagni explained Valfalva's doc- trine more fully. Valfalva gives the following reafons for his opinion. He obferves the feminary vellels of feveral fowls to come out from thefe capfula;, before they arc fent from the tefticles. In the viper and water tortoife, he re- marks fuch membranous connections between the renesfuc- centuriati, and tefticles, as make it probable that fuch excre- tories are fent through the capfula; to the tefticles. He af- firms, his having feen vefl'els, which were neither nervous, fanguiferous, or lymphatic, going from the human capfula; to the tefticles. His obfervations are much the fame as to females. To thefe he fubjoins the confent and fympathy obferved between the loins and genital parts. To confirm all he cut away one tefticle, and extirpated the kidney of the oppofite fide, of a whelp. The wounds healed, but the creature was of a very lax habit, and fo far from attempting coition, that he did not feem fond of bitches when they were proud. Acad. Bonon. Comment, p. 376. & feq. See alfo Phil. Tranf. N° 387. Sedf. 3. where we have an inquiry into this difcovery, made by Valfalva, of an excretory duct from the glandula renalis to the epididymis by Mr. John Ranby. And in N° 395. ScS. 12. there are mentioned, by the fame gentleman, two newly difcovered arteries in women going to the ovaria ; which he thinks to be probably the fame with what Valfalva took for excretory ducts of the trlandula; renales. Valfalva's difcovery was firft mentioned fn tie gitrmk di htcrati of Venice for 1719, and inferted in the Phil. Tranf. N J 385. Sefl. 9.

RENETTE, in the manege, is an inftrument of pohfhed fteel, with which they found a prick in a horfe's foot.

RENIFORM leaf, among botanifts. See Leaf.

RENTAL, a roll wherein the rents of a manor are written and fet down, and by which the lord's bailiff collects the fame : it diftinguilh.es the lands and tenements, and the names of the tenants, the feveral rents arifing, and for what time, ufuallyayear. Comp. Court Keep. 475.

REPART, in the manege, is to put a horfe on, or make him part a fecond time.

REP AND leaf, repandnm folium, among botanifts. See the article Leaf.

REPHON. See the article Re mphan.

REPOLON, in the manege, is a demivolte, the croupe in, clofed at five times. The Italians are mighty fond of this fort of manege. In making a demivolte, they ride their horfes ftiort, fo as to embrace or take in lefs ground, and do not make way enough every time of the demivolte.

REPRISE, in the manege, is a leflbn repeated, or a manege recommenced. Thus we fay to give breath to a horfe up- on the four corners of the volte with only one rtfrife, that is, all with one breath.

REPROOF, objurgatio, in rhetoric, is diftinguifhed from in- veclive. See the article Invective.

REPRODUCTIVE fyjitm of prefervation. See the article Annihilation.

RERE county, a word ufed in the ftatutes of Weftm. 2. c. 39. And 2 Ed. 3. c. 5. And feems by thofe ftatutes to be fome public place, which the fheriffs appointed for the re- ceiving of the king's money after his county court was done. Terms of Law. Blount.

REPUDIUM, among the Romans. See Divorce.

RESCUSSOR, in law, the party that commits a refcous. 2 Cro. 419. Blount.

RESEDA, baft rocket, in botany, the name of a genus of plants, the characters of which are thefe. The flower is of the polypetalous anomalous kind, confiding of feveral dif- fimilar petals ; from the cup of which there arifes a piftil, which finally becomes a membranaceous capfule ufually of a trigonal form, or elfe fquare, though fometimes oblong and cylindric, and containing roundilh feeds. The fpecies of refeda enumerated by Mr. Tournefort are thefe. 1. The common refeda. 2. The French refeda with curled leaves. 3. The broad leaved refeda with yellow flowers. 4. The white flowered refeda with leaves like the calcitrapa. 5. The common fmall refeda, called by many authors the phyteuma. 6. The common Iefler refeda with leaves not fo deeply cut. 7. The common whole or uncut leaved fmall refeda. Town. Inft. p. 423.

RESIANT rolls, are rolls wherein the refiants of a tithing, lie. are fet down. Comp. Court Keep.

RESIDUARY legatee, is he to whom the refiduum, or what remains of an cftate, after funeral charges, debts, and lega- cies are paid, is left by will.

RESIN (Cycl.) — According to Theophraftus re/in was ob- tained by ftripping off the bark from pines, and by incifions made in the filver fir and the pitch pine. The inhabitants of mount Ida, he tells us, ftripped the trunks of pines, on the funny fide two or three cubits from the ground. He ob- ferves, that a good pine might be made to yield refin every year, but the indifferent pines only every other year, and the weaker trees once in three years ; and that three run- nings were as much as a tree could bear. It is remarked

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by the fame author, that a pine doth not at once produce fruit and refln; but the former only in its youth and the latter in its old age. RESISTANCE (Cycl.)— Resistance of fluids. The great- eft part of authors have eftablifhed it as a certain rule, that, whilft the fame body moves in the fame medium, it is al- ways refljied in the duplicate proportion of its velocity ; that is, if the refljied body move in one part of its track, with three times the velocity with which it moved in fome other part, then its reflflance to the greater velocity will be nine times the reflflance to the lefier. If the velocity in one place be four times the velocity in another, the reflflance to the greater velocity will be fixteen times the reflflance to the Iefler^ and fo on. This rule, though exceflivcly erroneous, when taken in a general fenfe, is yet undoubtedly very near the truth, when confined within certain limits. In order to conceive the reflflance of fluids to a body moving in them, it is neceffary to diftinguiih between thofe fluids which being comprefled by fome incumbent weight, per- petually clofe up the fpace deferted by the body in motion, without permitting, for an inftant, any vacuity to remain behind it ; and thofe fluids in which (they being not fuffi- ciently comprefled) the fpace left behind the moving body remains for fome time empty. Thefe differences, in the refilling fluids, will occafion very remarkable varieties in the laws of their reflflance, and are abfolutely ncceflary to be confidered in the determination of the action of the air in fhot and fhells ; for the air partakes of both thefe affections, according to the different velocities of the projected body. If a fluid was fo conftituted, that all the particles compofing it were at fome diftance from each other, and there was no action between them, then the reflflance of a body moving therein, would be eafily computed, from the quantity of motion communicated to thefe particles : for inftance, if a. cylinder moved in fuch a fluid in the direction of its axis, it would communicate to the particles it met with a velocity equal to its own, and in its own direction, fuppofmg that neither the cylinder, nor the parts of the fluid were elaftic ; whence, if the velocity and diameter of the cylinder be known, and alfo the denfity of the fluid, there would thence be determined the quantity of motion communicated to the fluid, which (action and re-action being equal) is the fame with the quantity loft by the cylinder, consequently the re- flflance would be hereby afcertained.

In this kind of difcontinued fluid, the particles being de- tached from each other, every one of them can purfue its own motion in any direction, at leaft for fome time, independent of the neighbouring ones ; wherefore, if, inftead of a cy- linder, moving in the direction of its axis, a body, with a furface oblique to its direction, be fuppofed to move in fuch a fluid, the motion the parts of the fluid will hereby acquire, will not be in the direction of the refljied body, but perpen- dicular to its oblique furface ; whence the reflflance to fuch. a body will not be eftimated from the whole motion commu- nicated to the particles ofthefluid, butfrom that partof it only, which is in the direction of the refljhd body. In fluids then, where the parts are thus difcontinued from each other, the different obliquities of that furface, which goes foremoft, will occafion confiderable changes in the reflflance ; al- though the fection of the folid, by a plain perpendicular to its direction, fhould in all cafes be the fame. And Sir Ifaac Newton has particularly determined, that in a fluid thus conftituted, the reflflance of a globe is but half the reflflance of a cylinder of the fame diameter, moving in the direction of its axis with the fame velocity.

But though the hypothefis of a fluid, thus conftituted, be of great ufe in explaining the nature of reflflances ; yet, in reality, no fuch fluid does exift within our knowledge : all the fluids with which we are converfant are fo formed, that their particles either lie contiguous to each other, or at leaft act on each other in the fame manner, as if they did; confequently, in thefe fluids, no one particle, conti- guous to the refljied body, can be moved, without moving at the fame time a great number of others, fome of which will be diftant from it ; and the motion thus communicated to a mafs of the fluid will not be in any one determined direction, but will in each particle be different, according to the different manners in which it lies in contact with thofe, from which it receives its impulfe ; whence, great num- bers of the particles, being diverted into oblique directions, the refljlance of the moving body, which will depend on the quantity of motion communicated to the fluid in its own direction, will be hereby different in quantity, from what it would be in the preceding fuppofition, and its eftimation becomes much more complicated and operofe. If the fluid be comprefled by the incumbent weight of its upper parts (as all fluids are with us, except at their very furface) and if the velocity of the moving body be much lefs than that with which the parts of the fluid would rum into a void fpace, in confequence oi their compreflion ; it is evi- dent, that in this cafe the fpace left by die moving body will be inftantaneoufly filled up by the fluid ; and the parts of the fluid, againft which the foremoft part of the body prefles in its motion, will, inftead of bqing impelled forwards in the 3 direction