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or 125 feet in 1"; and the time of its paffing through that space being about 32 or of 1", the medium quantity of refiftance muft, in thefe inftances, have been about 120 times the weight of the ball; which as the ball was nearly

of a pound, amounts to about 10 lb. avoirdupoife.

bafis, and then its vertex foremost, has its refftances, as the tangent to an arch of a circle, whofe diameter is equal to the parameter, and the tangent equal to half the basis of the parabola. 5. The refiftances of an hyperbola, or the semiellipfis, when the bafe and when the vertex goe foremost, may be thus computed; let it be, as the fum, or difference, of the tranfverfe axis, and latus rectum, is to the tranfverfe axis, fo is the fquare of the latus rectum to the fquare of the diameter of a certain circle; in which circle apply a tangent equal to haif the basis of the hyperbola or ellipfis. Then fay again, as the fum, or difference, of the axis and parameter is to the parameter, fo is the aforefaid tangent to another right line. And further, as the fum, or difference, of the axis and parameter is to the axis, fo is the circular arch, correfponding to the aforefaid tangent, to another arch. This done, the refiftances will be as the tangent to the fum, or difference, of the right line thus found, and that arch laft mentioned. 6. In general, the refiftances of any figure whatfoever going now with its base foremost, and then with its vertex, are as the figures of the bafis to the fum of all the cubes of the element of the bafis divided by the squares of the element of the curve line.

All which rules, he thinks, may be of ufe in the fabric or construction of ships, and in perfecting the art of navigation univerfally. As alfo for determining the figures of the balls of pendulums for clocks. See the article SHIP, &c.

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As to the refiftance of the air, Mr. Robins, in his new principles of gunnery, took the following method to determine it he charged a musket-barrel three times fucceffively with a leaden ball of an inch diameter, and took fuch precaution in weighing of the powder, and placing it, as to be fure, by many previous trials, that the velocity of the ball could not differ by 20 feet in 1" from its medium quantity. He then fired it against a pendulum, placed at 25, 75, and 125 feet diftance, &c, from the mouth of the piece respectively. In the firft cafe it impunged against the pendulem with a velocity of 1670 feet in 1"; in the fecond cafe with a velocity of 1550 feet in "; and in the third cafe with a velocity of 1425 feet in 1"; fo that in paffing through 50 feet of air, the bullet loft a velocity of about 12,9,

Now if a computation be made, according to the method laid down for compreffed fluids in the 38th Propof. of lib. 2. of Sir Ifaac Newton's Principia, fuppofing the weight of water to be to the weight of air, as 850 to 1, it will be found that the refiftance of a globe of three quarters of an inch diameter, moving with a velocity of about 1600 feet in 1", will not, on thofe principles, amount to any more than a force of 4th. avoirdupoife; whence we may conclude (as the rules in that propofition for flow motions are very accurate) that the refifting power of the air in flow motions is less than in fwift motions, in the ratio of 4 to 10, a proportion between that of 1 to 2, and 1 to 3. Again charging the fame piece with equal quantities of powder, and balls of the fame weight, and firing three times at the pendulum, placed at 25 feet diftance from the mouth of the piece, the medium of the velocities with which the ball impinged was 1690 feet in 1′′. Then removing the piece 175 feet from the pendulum, the velocity of the ball, at a medium of five fhots, was 1300 feet in 1". Whence the ball, in paffing through 150 feet of air, loft a velocity of about 390 feet in 1"; and the resistance, computed from thefe numbers, comes out fomething more than in the preceding inftance, amounting to between 11 and 12 pounds avoirdupoife: whence, according to thefe experiments, the refifting power of the air to fwift motions is greater than in flow ones, in a ratio which approaches nearer to the ratio of 3 to 1, than in the preceding experiments.

Having thus afcertained the refiftance to a velocity of near 1700 feet in 1", he next proceeded to examine this refistance in fmaller velocities: the pendulum being placed at 25 feet distance, was fired at five times, and the mean velocity with which the ball impinged was 1180 feet in 1". Then removing the pendulum to the distance of 250 feet, the medium velocity of five fhot at this diftance, was 950 feet in 1"; whence the ball, in paf

for what is more ufually called analyfic, or the analytic method. See the articles ANALYSIS and METHOD.

hing through 225 feet of air, loft a velocity of 230 feet in 1", and as it paffed through that interval in about 3 of 1", the refiftance to the middle velocity will come out to be near 33 times the gravity of the ball, or 2 lb. 10 oz. avoirdupoife. Now the refiftance to the fame velocity, according to the laws obferved in flower motions, amounts to 7 of the fame quantity; whence in a velocity of 1065 feet in 1", (the medium of 1180 and 950) the refifting power of the air is augmented in no greater proportion than of 11 to 7; whereas in greater degrees of velocity, as before, it amounted very near the ratio of 3 to 1.

That this refifting power of the air to fwift motions, is very fenfibly increased beyond what Sir Ifaac's theory for flow motions makes it, feems hence to be evident. It being, as has been faid, in musket, or cannon fhot, with their full charge of powder, near three times the quantity affigned by that theory. The refiftance of a bullet of three quarters of an inch diameter, moving in air with a velocity of 1670 feet in 1", amounting, as we faid, to 10 lb, the refiftance of a cannon ball of 24 lb. fired with its full charge of powder, and thereby moving with a velocity of 1650 feet in ", may hence be determined. For the velocity of the cannon ball being near the fame as the mufket bullet, and its furface above 54 times greater, it follows, that the resistance on the cannon ball will amount to more than 540 lb.. which is near 23 times its own weight. And from hence it appears how rafh and erroneous the opinion of thofe is, who neglect the confideration of the refistance of the air as of no importance in the doctrine of projectiles. See the articles PROJECTILES and GUNNERY. RESISTANCE of the fibres of folid bodies is more properly called cohesion. See the article COHESION

Solid of leaft RESISTANCE. See SOLID. RESOLUTION, in chemistry, &c. the reduction of a mixed body into its component parts, or first principles, by a proper analyfis. See the articles MENSTRUUM and SOLUTION.

The refolution of bodies is effected by
divers operations, as distillation, fubli-
mation, fermentation, precipitation, &c.
See the articles DISTILLATION, SUB-
LIMATION, &c.

Some logicians ufe the term refolution
VOL. IV.

RESOLUTION, in medicine, that coction or alteration of the crude peccant matter of any difeafe, either by the natural Atrength of the patient, or of its own accord, or by the application of remedies, whereby its bulk, figure, cohefion, &c. are lo far changed, as that it ceases to be morbid, and becomes laudable. This Boerhaave obferves, is of all others the most perfect cure, where it is effected without any evacuation, as fuppofing the matter favourable, the conftitution excellent, and the medicines good. RESOLUTION, in mufic, is when a canon or perptual fugue is not wrote on a line, or in one part, but all the voices that are to follow the guide or first voice are wrote feparately either in fcore, that is in feparate lines, or in feparate parts, with the paufes each is to oblerve, and in the proper tone to each.

RESOLVENTS, refolventia, in medicine, remedies proper to refolve and diffipate tuntors and gatherings, to foften indurations, and, by their tenuity and warmth, evacuate redundant and peccant humours through the pores. Under this clafs come various unguents, emplafters, &c. RESONANCE, RESOUNDING, in mufic, &c. a found returned by the air, inclosed in the bodies of ftringed mufical inftru-. ments, as lutes, &c. or even in the bodies of wind inftruments, as flutes, &c. See SOUND and Music.

Elliptic and parabolic vaults, refound ftrongly, that is, they will reflect or return a found. The mouth and the parts thereof, as the palate, tongue, teeth, nofe, and lips, Monfieur Dodart obferves, contribute nothing to the tone of the voice, but their effect is very great as to the refonance: of this we have a very fenfible inftance in that vulgar inftru ment called a jews-harp, or trompe de Bearn; for if you hold it in your hand, and ftrike the tongue or fpring thereof, which is the method practifed to found this inftrument, it yields fcarce ary. noife, but holding the body of it between the teeth, and friking it as before, it makes a musical buzz, which is heard at a good distance, and especially the

lower notes.

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the tune of refonance produced in the mouth, by the greater or lefs aperture, and the various motions of the lips. RESORT, or RESSORT. See RESSORT. RESPECTU COMPUTI VICECOMITIS

HABENDO, in law, a writ directed to the treasurer and barons of the exchequer for the refpiting of a sheriff's

account.

RESPIRATION, refpiratio, the act of refpiting, or breathing the air. What

refpiration is, and why it is uninterruptedly carried on without the concurrence of the mind, will appear from the following confiderations of Boerhaave. The lungs fufpended in the air, which every where acts upon them, and equally preffes them always, collapfe, contract themselves into a fmaller space, and become much less than when they remained in the intire thorax. This is principally performed by the contractile force of the mufcular fibres, which connect the fquamous fegments of the bronchia If the lungs thus contracted, are filled with air, forcibly blown through the glottis, they are fo diftended as in bulk not only to equal that which they had in the intire thorax, but even to exceed it all which is fufficiently certain from experiments. The fame thing happens if, when an accefs for the air through the glottis is left to the lungs, the air, externally acting on the lungs, is either removed, or its preffure diminished. Hence it is obvious, that the lungs, by their proper force have always a tendency to become lefs in all their parts than they are when placed in the intire thorax. For this reafon, it is certain that they are in a continual ftate of diftraction fo long as a perfon is alive, fo that they must collapfe, and be diminished, whilft the whole of the animal remains in a vacuum, obtained by an exhauftion of the air in an air-pump. For there is nothing fimilar to a circumambient air between the external membrane of the lungs, and all the internal furface of the pleura in a found perfon; nothing therefore externally compreffes the lungs, except the diaphragm. There is, however, always an internal air contained in them, and freely conveyed to them through the glottis. Hence the lungs are always fomewhat more diftended by the internal, than they are compreffed by the external, air, the access of which is hinder

ed by the diaphragm, which is fo connected with the ribs and vertebræ, that the air cannot enter the thorax in fuch a manner as would be requifite for an equilibrium. See the article LUNGS, DIAPHRAGM, &c.

Since, therefore, in infpiration, a greater quantity of air enters the lungs through the glottis, it will extend the lungs more, and overcome their natural force, fo that in this action the lungs are paffive; but how far they are active is only to be difcovered from certain phænomena. In vital infpiration, then, especially confidered in a fleeping perfon, first the ribs, particularly the nine fuperior ones, articulated at the vertebræ, and by cartilages joined to the sternum, with their arched part, rife to the clavicles, fo that this motion is principally obferved in the middle of the arch, whilst three, or perhaps four, inferior ribs are turned downwards, backwards, and obliquely outwards, but in such a manner that the seventh, eighth, ninth, and tenth ribs are by their cartilaginous fegments, as it were, drawn inwards. Secondly, the whole abdomen, to the very end of infpiration, is gradually rendered more tumid and preffed downwards. Thirdly, at the fame time the cavity of the thorax is enlarged, as is obvious from repeated experiments. Whilft the parts remain in this fituation, the air acts upon the lungs with a force equal to that with which the thorax refilts, fo that the lungs will remain in a ftate of rest. Hence lefs blood will pafs through them, and a fmaller quantity of it will be forced into the left ventricle of the heart, and confequently lefs blood will be conveyed to the cerebellum and its nerves. The arterial blood will alfo act lefs upon the intercoftal muscles and diaphragm, fo that the caufes dilating the thorax are weakened. Hence the elafticity of the cartilaginous fegments again depreffes the ribs, in which work they are alfo affifted by the mufcular fibres arifing from the fide of the fternum within the thorax, and inferted into the bony extremities, and cartilages of the true ribs. At the fame time the distracted fibres of the peritoneum and abdominal mufcles reftore themselves. Hence the compreffed vifcera thrust the relaxed diaphragm upwards into the thorax, which is by this means contrafted, and the air expelled from the

lungs.

lungs. By this means, expiration and the action already mentioned, are performed. But in a particular manner by these two actions the blood is not only carried through the lungs, but its motion accelerated. See CIRCULATION, &c. Phyficians are not agreed about the ufe and effects of refpiration; fome think that the air is infinuated into the veels of the lungs, to give a greater fluidity and motion to the blood; others, that it conveys very fubrile nitrous corpucles thereunto, which gives it the red colour; others again believe the air feives to condense the blood, which has been heated by circulation. This is certain, that the air entering into the lungs, and all the fmall ramihcations which furround its vehicles is broke, comminuted, and rendered more fluid, and that it is deprived of a ferofity, which proceeds from the lungs by perfpiration in the form of a vapour that is visible in cold weather. It may be added, that the voice, laughter, coughing, fneezing, yawning, and fucking, depend upon tespiration. Boerhaave takes the principal ules of refpiration to be the further preparation of the chyle, its more accurate mixture with the blood, and its converfion into a nutritions juice, proper to repair the decays of the body, Other authors take a great use of refpiration to be, by the neighbourhood of the cold nitrous air, to cool the blood coming reeking hot out of the right ventricle of the heart through the lungs, and to act as a refrigeratory; others affert one grand ufe of refpiration to be the throwing off the fuliginous vapours of the blood, along with the expelled air; and for infpiration they affert, that it conveys a nitro aerial ferment to the blood, to which the animal fpirits, and all mufcular motion, are owing. But Dr. Thurston rejeas all thefe, as being the principal ufes of refpiration, and from the experiments of Dr. Croon, Dr. Hook, and others, made before the Royal So. ciety, he fhews the principal use of refpiration to be that of moving, or paffing the blood from the right to the left ventricle of the heart, and fo to effect circulation; whence it is, that perions hanged, drowned, or ftrangled, fo fuddenly die, viz. because the circulation of the blood is stopped, and for the

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but carries farther, making it the true caufe of the diaftole of the heart, which neither. Bore!!i, Dr. Lower, nor Mr. Cowper, had well accounted for. See the articles DIASTOLE and SYSTOLE. From experiments made upon dogs, and other animals, Dr. Hales fhews, that without refpiration, the blood world foon turn putrid and peftilential; and indeed the only animal exempted from the nec.ffity of refpiration is a foetus. See the article FOETUS.

With regard to the force of refpiration, the laft mentioned author obferves, that though a man by a peculiar action of his mouth and tongue, nav fuck mercury twerty-two inches, and fome men twenty leven or twenty eight, high, yet he found from experience, that by the bare inipiting action of the diaphragm and dilating thorax, he himself could forcely raife the mercury two inches, at which time the diaphragm mult act with a force equal to the weight of a cylinder of mercury, whole baie is commenfurate to the area of the diaphragm, and its height two inches, whereby the diaphragm must at the fame time fuftain a weight equal to many pounds; neither are its counteracting mufcles, thofe of the abdomen, able to exert a greater force.

With regard to the quantity of moisture carried off by respiration, the Doctor, from an experiment on wood-afhes, eftimates that quantity to be equal to feventeen grains in fifty expirations, whence there will proportionably be four hundred and eight grains evaporated or breathed off in twelve hundred expira tions, being the number in an hour, and thence in twenty four hours 9792 grains, or 1.39 pounds, which fuppoting the furface of the lungs to be 41635 fquare inches, then the quantity evaporated from that inward furface will be 7+ th part of an inch depth. From the violent and fatal effects of very noxious vapours on the refpiration and life of animals, the Doctor fhews how the refpiration is proportionably incom moded when the air is loaded with leffer degrees of vapours, which vapours do in fome measure clog and lower the air's elafticity, which it beft regains by hav ing thefe vapours difpelled by the ventitilating motion of the fice open air, that is belt rendered wholfome by the agita

fame reafon it is, that animals die fotion of winds; thus what we call a clofe

fpeedily in the air-pump. This ufe of refpiration Dr. Drake not only confirms,

warm air, fuch as has been long contined in a room, without having the vapours 16 Ca

in

RESPONSE, an answer or reply. A word chiefly used in fpeaking of the answers made by the people to the priest, in the litany, the pfalms, &c. RESSAULT, in architecture, is the effect of a body which either projects or finks back; that is, ftands more out or in, than another, fo as to be out of the line or level with it.

in it carried off by communicating with the open air, is apt to give us more or lefs uneafinefs in proportion to the quantity of vapours which are floating in it. And thus many of those who have weak lungs, but can breathe very well in the fresh country air, are greatly incommoded in their breathing, when they come into large cities where the air is full of fuligenous vapours; and even the most robust and healthy, in changing from a city to a country air, find an exhilerating pleasure arifing from a more free and kindly infpiration, whereby the Jungs being lefs loaded with condensing air and vapours, and thereby the vehicles more dilated with a clearer and more elastic air, a freer courfe is thereby given to the blood, and probably a purer air mixed with it. See the article AIR. RESPITE, in law, &c. fignifies a delay, forbearance, or prolongation of time, granted any one, for the payment of a debt, or the like.

RESPONDENT SUPERIOR, in law, is a fuperior's anfwering for the infufficiency of an inferior. Thus, if the fheriffs of London are infufficient, the lord mayor and commonalty muft anfwer for them, as the fheriffs fuperior. ·

Superior officers must alfo answer for their deputies, in civil actions, in cafe they are infuficient to answer damages; as where a gaoler deputes another under him, and the perfon deputed fuffers an efcape, the gaoler mult anfwer for his deputy's infufficiency.

RESPONDENT, in the fchools, one who maintains a thefis, in any art or science; who is thus called, from his being to anfwer all the objections propofed by the opponent.

The relpondent is to fee whether the pofition made by the contrary party be jutt and legitimate; or whether some of the laws of oppofition be not broken. He is alfo to manage the modes and figures of the fyllogifms, to fee whether the premises be just; and through the whole, to answer rather by diftinguos, than by direct negation.. RESPONDENT, in law, a perfon who undertakes to answer for another; and also, one who binds himlelf as a fecurity for another perfon's good behaviour. RESPONSALIS, in law, is a perfon who astovers for another, in court, at a day signed.

RESPONSARY SONG, an anthem, in which the charifters fing by turns.

RESSORT, or RESORT, a french word, fometimes ufed by english authors, to fignify the jurifdiction of a court, and particularly one from which there is no appeal.

Thus it is faid, that the house of lords judge en dernier reffort, or in the last resfort. RESSOURCE, a fench word, used by engJifh writers, to denote an after-game, for recovering a perfon's loffes, or fomething to apply back to, for fuccour. REST, quies, the continuance of a body in the fame place, or its continual application or contiguity to the fame parts of the ambient or contiguous bodies; and, therefore, is opposed to motion. See the article MOTION.

Sir Ifaac Newton defines true or abfolute reft, to be the continuance of a body in the fame part of abfolute space; and relative reft to be the continuance of a body in the fame part of relative space. See the article SPACE.

It is one of the laws of nature, that matter is indifferent to motion or reft, as has been fhewn under the article INERTIA. Reft, confidered in a phyfical view, is only falutary, in fo far as it is duly proportioned to the exercife; for a fedentary idle life brings on many indispositions. See the article EXERCISE. REST, in poetry, is a fhort pause of the voice, in reading, being the fame with the cæfura, which, in alexandrian verses, falls on the fixth fyllable; but in verfes of ten or eleven fyllables, on the fourth. See the articles CÆSURA, ALEXANDRIAN, &c.

REST, in mufic, the fame with paufe. See the article PAUSE.

RESTAURATION, the act of re-eftablishing or fettling a thing in its former good itate. RESTAURATION, in architecture, the act of repairing thofe parts of a building that are gone to decay, in fuch a manner as to give it its original ftrength and beauty.

From the plinths of the corinthian columns of the Pantheon, which are almoft

wholly

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