i. P. macr. albicans, the white blunt-nosed cachalot, of a white color with a smooth back. This is about fifteen or sixteen feet long, and Yesembles the common whale.

ii. P. macr. cinereus, the gray blunt-nosed cachalot; of a blackish ash color, with a hump on the back. This variety grows to sixty and even seventy feet long, by thirty or forty in circumference; has a very large head, with very small eyes; the lower jaw is much narrower than the upper, and is furnished with a considerable number of teeth, which are received into sockets of the upper jaw when the mouth is shut. It has a hump on the back, about a foot above the general surface. It is found in Davis's Straits.

iii. P. macr. niger, is black colored, and has a hump on the back twelve inches high. This variety is found in the European seas; it grows to about sixty feet long, and thirty-six in circumference: the head is exceedingly thick, and the lower jaw, which is smaller than the upper, has forty-six teeth in two rows, which rise two inches and a half above the gums, and are received into sockets in the upper jaw. The female teats are retractile. The substance improperly named spermaceti is procured from this species; and the spermaceti, or white oil, is extracted from it. It is found in the South coasts of Brasil, Patagonia, and the Pacific Ocean. Dr. Schwediaur says that ambergris is ejected from this animal. It feeds on the sepia octopodia.

3. P. microps, the black headed cachalot, with a long fin on the back, and the upper jaw considerably longer than the under one. A fish of this kind was cast ashore on Cramond Isle, near Edinburgh, December 22d, 1769; its length was fifty-four feet; the greatest circumference, which was just beyond the eyes, thirty; the upper jaw was fifteen feet; the lower ten. The head was of a most enormous size, very thick, and above onethird the size of the fish: the end of the upper jaw was quite blunt, and nearly nine feet high; the spout-hole was placed near the end of it. The teeth were placed in the lower jaw, twentythree on each side, all pointing outwards; in the upper jaw, opposite to them, were an equal number of cavities, in which the ends of the teeth lodged when the mouth was closed. One of the teeth measured eight inches long, the greatest circumference the same. It was hollow withinside for the depth of three inches, and the mouth of the cavity very wide: it was thickest at the bottom, and very small at the point, bending very much; but in some the flexure is more than in others. These, as well as the teeth of all other whales, are very hard, and cut like ivory. The eyes are very small, and remote from the nose. The pectoral fins were placed near the corners of the mouth, and were only three feet long; it had no other fin, only a large protuberance on the middle of the back. The tail was a little forked, and fourteen feet from tip to tip. The penis seven feet and a half long. Linnæus informs us that

this species pursues and terrifies the porpoises to such a degree as often to drive them on shore.

4. P. tursio, the high-finned cachalot, has a very long fin on the back, and the ends of the teeth are flat. It inhabits the Northern Ocean, and grows sometimes to 100 feet long; the back fin is very long, sharp-pointed, and erect, like a ship's mast, and the blowing-pipe is placed flat on the forehead: the teeth are slightly bent and have their ends flattened. PHYSIC, n. s. & v. a.` PHYSICAL, adj. PHYSICALLY, adv. PHYSICIAN, n. s.

Gr. puolen. Natural philosophy; particularly and

more

commonly the science of healing or curing diseases; remedies; medicines: to physic is to treat with medicine; and, sometimes, to cure: physical means relating to nature; helpful to health; natural as distinct from moral; medicinal: the adverb following these senses: a physician is one who professes the healing or medical art; one who prescribes medicines.

Use physick or ever thou be sick. Ecclus. xviii. 19. In itself we desire health, physick only for health's sake. Hooker. The labour we delight in physicks pain. Shakspeare.

It is a gallant child; one that indeed physicks the subject, makes old hearts fresh.

Id.

Is Brutus sick, and is it physical
To walk unbraced, and suck up the humours
Of the dank morning?
Id. Julius Cæsar.

Trust not the physician,
His antidotes are poison, and he slays
More than you rob. Id. Timon of Athens.

Some physicians are so conformable to the humour of the patient, as they press not the true cure of the disease; and others are so regular, as they respect not sufficiently the condition of the patient.

Bacon's Essays. Prayer is the best physic for many melancholy diseases. Peacham.

His gratulatory verse to king Henry is not more witty than the epigram upon the name of Nicolaus, an ignorant physician, who had been the death of thousands. Id. of Poetry.

The people use physick to purge themselves of huAbbot.

mours.

PHYSIC, OF PHYSICK, the art of healing, properly called medicine. The word is formed from the Gr. quoc, nature; either because medicine consists principally in the observation of nature, or that the most important natural observations first took this direction. See MEDICINE, PHYSIC, and PHYSICS.

PHYSICAL, Something belonging to, or really existing in nature. In this sense we say a physical point in opposition to a mathematical one, which only exists in the imagination; a physical substance or body, in opposition to spirit, or metaphysical substance, &c.

PHYSICIAN OF THE FLEET, in the royal navy, is a person appointed by the Admiralty with the medical superintendence of a fleet or squadron of ships employed on any particular_station, as the Channel, Mediterranean, West Indies, &c., and is under the immediate orders of the commander-in-chief: if an hospital ship is with the fleet, his residence is generally on board her; if not, it is usual for him to be in the flag-ship with the commander-in-chief.

The arrangement of every thing appropriated to the reception of the sick, sent on board the hospital ship for cure, shall be under his direction; and the surgeon, and all other persons appointed to attend them. He is to propose to the commander-in-chief every thing which he may think likely to be of service to the sick, to increase their comforts, or to accelerate their cure. He is also to visit the different ships of a squadron frequently; to enquire into the health of the ships' companies, and the treatment of the sick; and, if any unusual sickness prevails on board, he is to represent the same to the commander

of

in-chief, with the nature of the disease, and the necessary means which he deems requisite for eradicating and putting a stop to the progress the malady. He is also authorised to examine the journals of the medical officers, to enquire into the practice of the surgeon of any ship he visits, and his manner of treating the diseases of the men under his care, and to give him such directions as he may deem necessary. He is also to enquire into the conduct and abilities of the assistant-surgeons, that he may be able to point out to the sick and hurt board, or to the commanderin-chief, those who may he best qualified for any particular service, or for promotion. And, whenever he shall think it necessary, he is to examine the instruments, medicines, and necessaries, on board any ship.

PHYSICIAN OF A NAVAL HOSPITAL, is a person appointed by the admiralty to one of his majesty's naval hospitals, to superintend and prescribe medicine for the inward complaints of the sick and wounded seamen; and to attend such physical patients every day, or as often as circumstances may require.

PHYSICIANS. According to an ancient statute no person within London, or seven miles thereof, shall practise as a physician or surgeon, without license from the bishop of London, or dean of St. Paul's; who are to call to their assistance four doctors of physic, on examination of the persons, before granted and in the country, without license from the bishop of the diocese, on pain of forfeiting £5 a month. Stat. 3 Hen. VIII. c. 11. By the charter for incorporating the College of Physicians, they have power to choose a president, and have a perpetual succession, a common seal, ability to purchase lands, &c. Eight of the chiefs of the college are to be called elects, who from among themselves shall choose a president yearly and if any practise physic in the said city, or within seven miles of it, without license of the college under their seal, he shall forfeit £5. Also persons practising physic in other parts of England are to have letters testimonial from the president and three elects, unless they be graduate physicians of Oxford or Cambridge, &c. Stat. 14 and 15 Hen. VIII. c. 5, confirmed and enlarged by stat. 1 Mary, stat. 2, c. 9. 32 Hen. VIII. c. 40, ordains that four physicians, called censors, shall be yearly chosen by the college, to search apothecaries' wares, and have an oath given them for that purpose by the president; apothecaries denying them entrance into their houses, &c., incur a forfeiture of £5. And physicians refusing to make the search are liable to a penalty of 40s. And every member of the College of Physicians is authorised to practise surgery.

PHYSICIANS, COLLEGES OF. See COLLEGE. PHYSICO-MATHEMATICS, a science which includes those branches of physic, which, uniting observation and experiment to mathematical calculation, undertake to explain the phenomena of

nature.

PHYSICO-THEOLOGY, from physic and theology. Divinity enforced or illustrated by natural philosophy.

PHYSICS, Lat. physica, of Gr. quoc nature, is a term that has been used as synonymous both with PHYSIOLOGY, which see, and natural philosophy. It has, therefore, been made to embrace the entire doctrine of the bodies and existences of the universe; their phenomena, causes, and effects.

Mr. Locke would include God, angels, and spirits, under this term; but these are more usually referred to metaphysics. The more immediate and proper objects of physics are said to be body, space, and motion.

The origin of physics, thus considered, is referred, by the Greeks, to the barbarians, viz. the brachmans, magi, and the Hebrew and Egyptian priests.

From these it was derived to the Greek sages or sophi, particularly to Thales, who is said to have first professed the study of nature in Greece. Hence it descended into the Pythagoric, Platonic, and Peripatetic schools; whence it was propagated into Italy, and thence through the rest of Europe: though it is clear that the Druids, Bards, &c., had a system of physics of their own.

PART I.

HISTORY OF PHYSICAL SYSTEMS. Treatises upon this subject have usually embraced, therefore, an account of the ancient systems of the universe, replete as they are with exploded errors. We know no writer who has placed the folly of this spirit of system, the idola tribus, specus, fori et theatri of lord Bacon in a more lively manner before his readers than the abbé le Pluche.

Though we commonly, he says, give the appellation of systems to the different suppositions by which Ptolemy, Copernicus, and Tycho Brahe, have endeavoured to account for the course of the heavens, it is not what we now mean by general and systematical physics. We are now supposed to be considering a philosophy which undertakes to explain the profound construction of the whole universe. The project is noble: various celebrated philosophers have employed themselves in it; they have made numerous parties, and many disputes. The history of their pretensions may either determine us in the choice of the best side, or in remaining entirely neuter.

Epicurus, reviving the ideas of Leucippus and Democritus, thought he very well comprehended that particles of matter different in form, having subsisted from all eternity, had, after a certain time, linked themselves to one another in the vacuum; that some proceeding in straight lines, and others in curved, fell into different clusters, and formed bodies and spirits; that the free agency of man was, above all, the work of atoms which moved in a declining line; thus chance made the sun, peopled the earth, established the order which subsists in it; and framed, out of one and the same paste, the world, and the intelligent being which is the spectator of it; that we are not to imagine the sun was made to light us, or

our eyes to see; but we having perceived that the sun might serve to light us, and that our eyes might serve to see with, we made use both of the sun and our eyes to that purpose.

Aristotle, and his partisans, believed the world was composed of a first matter, which, they say, had no form, but is capable of all forms; out of which the four elements issued, composing all bodies, and into which they are all resolved, or return in their last analysis. There is, indeed, some difference between this first matter and the atoms; but Epicurus and Aristotle agree in this, that they admit, at setting out, a first fund of indeterminate matter, capable of entering into all sorts of conditions and compositions.

Gassendi resumes these atoms and this vacuum of Epicurus for the construction of his world, with this difference, that he put them all into the hands of God, to give them motion according to the wise designs of his Providence.

Descartes rejects the vacuum, and will have every thing in his world full; though we can hardly reconcile the liberty of motion with a thorough exactness of plenitude. It is thus that he conceives of the creation of the world:-God, in the first place, formed an immense mass of homogeneous matter; all the different parts of which were cubical, or at least angular. He afterwards impressed on these particles a double motion. He makes the greater part of them turn on their centre, and several clusters among them round their common centre, which he names vortices. This being done, according to him, all is done; and by the friction of the angles of these parcels, from thence was formed a very fine dust, which he calls the first element or subtile matter; next a globulous matter, which he calls the second element or light; and lastly, a massive dust striped and branched, which he names the third element, from which he formed all sorts of massive bodies. This chaos, coming out of the hand of God, disposed itself in order, according to Descartes, by virtue of the two motions impressed upon it by God, and of itself became a worki like ours; in the which, though that God placed no order or proportion,' these are his own terms. one may see all things, as well general as particular, which appears in the real world.'

The alchymists, to be in a condition to make gold, and to prepare a restorative which immortalizes, or at least greatly prolongs life, were obliged to search to the profound of nature, and found they imagined, that salt, sulphur, and mercury, with some other ingredients, respecting which they could not agree upon among themselves, were certainly the immediate elements of metals, and all bodies; but yet there was really a first matter susceptible of all sorts of forms, as all the sages of Egypt and Greece, and all the philosophers of all ages averred; wherefore they had nothing to do but to work upon this first matter, to mould it different ways, and to give it a certain turn, to be possessed of gold, jewels, and the vivifying elixir.

Hitherto, then, we see a perfect agreement

among all these sects of philosophers upon the principal point. They all, though under different terms, go back to a chaos of the first matter, and numberless particles which are neither gold, silver, salt, bud, fruit, or any thing determinate but which will serve for a composition of all things, by their mixtures; and into which all things may at last be resolved. The only difference we find between them in this point is, that the alchymists have more wit than the others, and make a better use of wisdom. The Aristotelians and the Corpusculists are always ready to enter into the lists about a plenum and vacuum, matter and form, the principles of bodies, and the last term of their dissolutions, and all this to no purpose. They are all battling among themselves about the best method of disposing of matter, as if the world was now to be made or governed. But, alas, it is already made, and goes on in its course without them! According to Aristotle, Epicurus, Gassendi, and Descartes, gold and sand are originally the same matter. Descartes, by breaking his cubes, saw sun, gold, and light itself, arise. Let us put the sand into motion by force of fire and friction, break its angles, deprive it of that accidental form which makes it sand, and by a proper manuduction transmute it into gold. What riches! what felicity and assistance to human society! should we once arrive to this point.

The alchemists, therefore, labored far more to the purpose apparently. If the systematical philosophers think rightly on the article of a first matter, in which they all agree, the latter think still better in reducing these speculations to practice, and attempting to change this matter so as to produce gold and immortality. But here, unluckily for the honor of this sort of philosophy, alchemists die; and not only so, but they sooner than others. The greater number of them are parched among their furnaces and pestiferous exhalations; and this is certain, they all ruin themselves. Their fruitless attempts prove the falsity of the principle which they had from the philosophers, and dispense with our entering into a tedious examination of this imaginary philosophy.

As it is but loss of time for us to stir the atoms of Gassendi, or to whirl about the angular bodies of Descartes, continues our lively abbé, we shall possibly find the attractive, centripetal, and centrifugal philosophers of the north turn to better account.

The difference between M. Descartes and Sir Isaac Newton is, that the former undertakes to account for every thing; and the other, modestly acknowledging that we are ignorant of the secrets of nature, pretends only to evince one matter of fact (see our article PHILOSOPHY) without undertaking to explain the cause; but as this one point extends, according to him, to all nature, his system for that reason becomes a kind of universal philosophy. According to M. Descartes, that gravity which causes bodies to fall is nothing different from the action of the fluids in which the planets are carried away; because all bodies moved and impelled by the bodies surrounding them, to describe a circular instead of a straight line, incessantly endeavour to recede from the

centre; whence it happens that when the parts of the vortex meet with the bodies which have no centrifugal force, or which have less, they are compelled to fly to the centre; so that the precipitation of heavy bodies towards the centre is nothing but the action of more active bodies which have a tendency to avoid it.

Sir Isaac Newton at first thinks with M. Descartes, from whom he had learned it, that all bodies continue in a state of inaction, or repose, till drawn out of it or interrupted. But again, Sir Isaac Newton imagines that he has observed throughout all nature, and it is the distinguishing point of his system, that all bodies attract one another in proportion to their distance and bulk; that they have a certain tendency towards, and press upon another; that the sun tends towards the earth, and the earth towards the sun; but that, the latter being incomparably larger, we perceive only the approaches of the former towards it: that in like manner the earth tends towards the stone which is separated from it by projection, as the stone tends towards the earth, or rather that, the stone attracts the earth to it, as the earth attracts the stone; but the earth, by reason of its bulk, having a stronger attraction than a small stone, it happens from thence that the earth does not quit its place, and that the stone approaches or is drawn to it by the attractive power which the earth exercises upon it.

the

This action, which Newton imagines he every where perceives between bodies and bodies, throughout all nature, he calls attraction, and gives it out as an effect residing in every part of the universe, without being able to assign other cause than the will of God to put all nature in motion. Thus, the earth moving round the sun, if it was only moved, and not drawn towards it, would infinitely recede from it. The moon, if it obeyed without obstacle the law of motion which carries it away, would avoid the earth, and at length disappear. In the same manner, if the earth obeyed only the law of attraction, that law by which the sun draws the earth to it, it would draw near to, and precipitate into the sun; moon, being only attracted, would fall upon the earth but the earth being moved and cast off from the sun, is at the same time drawn toward it; instead of receding from it in a straight line, this line will be curved by the attraction which brings it back to the sun : being always under the influence of two powers, one of which always removes it from the sun, and the other draws it back, it describes round the sun a curved line, which Newton demonstrates ought to be an ellipsis, or near to an oval. The moon, in like manner, obeying two powers, one which makes it fy from, the other which makes it tend towards the earth, revolves round it; the centrifugal and the centripetal forces are checks one upon the other; and the moon, instead of being carried far from us by the first power, or precipitated upon our earth by virtue of the second, is, by the impres sion of both, kept within its orbit.

'Sir Isaac Newton afterwards examines what would be the measures of motion of the moon beginning to fall towards the earth, from the height of its orbit, after it had lost its centrifugal force, and was freed from all attraction of the

earth. The distance of the moon from the earth is known, also the duration of its revolution; one may then know what is the portion of the orbit in a minute. Geometry teaches us what space the moon runs through in a right line falling towards the earth, by virtue of the force which makes it pass through its arch, or portion of its orbit. Afterwards, having laid it down that the attraction diminishes as the square of the distance increases, Newton finds by his calculations that the moon, in falling from its station, would at first fall fifteen feet in a minute; and that near the earth, by virtue of the same law, it would in a minute pass through 3600 times fifteen feet. Lastly, examining the spaces which a body of wood or stone let fall would pass through near the earth, he concludes, from the experience gained by the fall of bodies, that a stone runs in one minute, near our globe, through 3600 times fifteen feet. The moon, being loosed from its orbit, would therefore obey the same law which precipitates the stone. By a necessary consequence, if the stone was carried as high as the orbit of the moon, being there let fall, it would run through fifteen feet in a minute. Attraction and gravity are then one and the same thing.

'M. Privat de Molieres, of the Academy of Sciences, has retained, in his Philosophical Lectures, the ground-work of Newton's observations. He admits all the proofs which show that the same cause which makes a stone gravitate upon the earth makes the earth gravitate upon the sun and the moon upon the earth; but he attributes this effect to a cause very different from that which Newton has imagined. The French academician, at the same time that he extols the exactness of the geometrical system of the learned Englishman, finds it incompatible with the plan of nature. He is not reconciled to a principle which makes of our world, one All, whose parts are as naked, and less united than those of a skeleton. All the ideas which we have of mechanics seem to him to be overthrown by this imaginary attraction, which, according to the partisans of the English geometrician, reciprocally acts between bodies separated by a great vacuum, and makes them move in a void, without uniting by any intermediate bond. M. Molieres resumes the vortex of M. Descartes; the existence of which seems to him to be almost palpably nature. He corrects it in the whole; and, making all the effects which Newton had observed to flow from the very structure of the vortex, he in some measure reconciles the two contending schools. This vortex is no longer composed, as Descartes has imagined, of hard inflexible globules, but of small vortices, the particles of which are incessantly inclining to recede from their peculiar centre, while the whole tends to remove from the common centre. A solid body, as the moon or earth, cast into this vortex, ought immediately to be moved by it, and carried the same way with it; but the parts of this unwieldy body being strictly united, and at rest among themselves, make no effort for motion, and have no other impulsion than what the whole body of the planet receives from the vortex in which it floats; whereas the globules of the vortex have a double motion, and make a double ef

fort; all of them tend to remove from the common centre, the moment they are forced, by the surrounding vortices, to move in a circular line. Moreover, all the particles of these globules perform that in little, round their centre, which the great ones do in general round their common centre. From this double tendency results a double force, which more powerfully removes them from the centre than the motion impressed on the planet removes it from the centre of the sphere. The planet cast into this vortex has indeed received a centrifugal force, in receiving a circular motion; but, its parts being at rest, it has less centrifugal force than the vortex, in which this force is double, as well from the motion of the little vortices which fly from the common centre, as their particles, which all at the same time avoid their respective centres. Thus the centrifugal force in the matter of the vortex, exceeding the centrifugal force of the planet, ought to prevail: and, the planet tending less to recede from the centre than the matter which pushed it on, it must follow, that the earth will by degrees draw nearer to the sun, and the moon fall upon the earth. In a word, De Molieres makes use but of one action, or same cause, to produce the centrifugal force of the vortex, and to make the planets, and all solid bodies, gravitate to one and the same centre: instead of which Newton adds a motion impressed on all these bodies; another power and another law, which he names attraction, and which disposes them all to draw near to one another, with more or less velocity, in proportion to their solidity, or their distances; while, indeed, the second power is useless and inconceivable.

'M. de Molieres, after having given us this assistance, by his ingenious explanation of gravity, to comprehend the double centrifugal force of vortices, and the advance of solid bodies towards the centre, as a simple effect of this force, left us at first in doubt of the power he would make use of to sustain the planets in their orbit, and to prevent their falling upon the centre. But it was easy to perceive, at the same time, that he would be compelled to make use of different vortices, at least of different atmospheres, cast round the planets, to make them roll over one another, without falling, like the globules of different matter, which, crowding together, flatten a little by their pressure upon each other; while, in the interim, the centres which tend one towards another, by the impulsion of the encompassing vortices, can never approximate. This explanation of M. de Molieres is so much the more ingenious as it is not made use of for the creation of a world, but to give an idea of its motion and support, as it may be employed in the particular explanation of a number of phenomena, and of particular cases; such, for example, as the flux and reflux of the sea, by the pressure of the sphere of the moon on that of the earth; the shifting of the satellites of Jupiter, by the pressure of the sphere of Saturn on that of Jupiter; the attractions and repulsions of electric bodies, by the small atmospheres which they acquire or lose, according to the different manner they are touched; the dissolutions and fermentations in chemistry, by the different powers of the little