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vated by various practicioners, chiefly. Ifaac's niece, relates the affair in the German. The well-known Robert following words: (Elemens de NewBoyle was one of the first who pursued ton.) it from philofophical motives; but the Un jour en l'année, &c.” One foundation of our present theory is due day in the year 1666, Newton being to Tachenius, Becker, and Stahl. retired into the country, was led, by Among experimenters in this science, observing fruit falling from a tree, inProfeffor Boerhaave of Leyden, stands to a profound meditation on the cause first.

which thus dratvs all bodies in lines, The latter end of the seventeenth, that if prolonged would pass through and the beginning of the eighteenth the center of the earth. What, said centuries form an era of discoveries. he to himself, is this force, which canThe weight of the atmosphere disco- not pofibly arise from the falsely imavered by Torricellius, but not allowed gined vortices of Descartes? It acts by all the philosophical world, was de- upon bodies in proportion to their mafeifively thewn by Boyle, by the help ses, and not after the ratio of their furof the air pump, which he had greatly facës: it would act upon these fruits improved from an invention of Otto that have fallen, even if elevated Guericke. The various refrangibility thoufands of fathoms above the surface of the rays of light discovered by News of the earth. If this be true, this ton put an end to the attenipts of force must act from the regions in grinding lenses of the figure of the conic which the moon is placed even to the lections, but the reflecting instrument center of the earth; and consequently firft perfected by him remained tinat- this power, whatever it is, may be the tended for near fifty years. The velo- same which causes the planets to bend city of light observed by Romer, was towards the sun, and occasions the faconfirmed and established by Bradley, tellites of Jupiter to gravitate towards who first observed the aberration of the his body. Now, it is demonstrated by fixed stars. And the discoveries of inductions drawn from the laws of Hawksbee and Stephen Gray are the Kepler, that all these secondary plafoundation of our prefent electrical nets gravitate towards the centers of knowledge.

their orbits with a greater degree of After the quotations concerning gra- force at a less distance; that is to say, vitation, which were pointed out in with a force which is as the square of our last number, it will seem ftrange the diftance inversely. A body placed that the knowledge of this universal in the orbit of the invon, and another property of matter was really a difco- at the furface of the earth, ought both very of Newton, though fuspected and to gravitate according to this law if even known to so many before him. the fuppofition be true. In fact, the men who are bufied in In order to be assured that the force accumulating a stock of idens from the which retains the planets in their orbits inreitigations of others are not often is the same as that which causes heavy thofe who themselves add the most to bodies to fall to the earth, nothing the general mass of knowledge by their more is required than proper admeadiscoveries. Dr. Pemberton affures surement. It is only required to deus, that Newton was not intimately termine the space which a heavy body acquainted with the works of his con- falls through in a given time near the temporaries, even when far advanced furface of the carth, and what space a in life, and in the earlier part he might heavy body would fall through in the well be fapposed to have overlooked those fame time at the region of the moon. passages of the ancients which might have The moon itself is this heavy body, led him to the knowledge of gravity. and may be considered as really falling However, we are indebted to an acci- during the whole time the revolves in dental circumstance for this grand dif- her orbit

. But the prefent business is covery. Voltaire, who received his not an hypothesis, the work of fancy; information from Mrs. Conduit, Sir which may be adopted at pleasure to any facts; neither will a rough estimate By the order of time we approach serve the purpose of calculation. A near upon our own age, and, as the beginning mui be made by discovering scene expands before us, we become the the exact distance of the moon, and for less inclined to attempt any thing bethis purpose it is necessary first to know yond a mere sketch. The present dethe magnitude of our globe.

partment of our work is not professedly Thus it is that Newton reasoned, historical. Our chief endeavour will but the measure he made use of de- be to lay before our readers an account pended on the false eftimate of fearnen, of the arduous undertakings, the discowho allowed fixty English miles to a veries, and the researches which endegree of the meridian,

instead of near gage the attention of the vast body of feventy, which is the truth. It must philosophers of the several academies be confessed that there was a more exact and societies of Europe. A familiar admeasurement extant. Norwood, an and rational account of every interestEnglish mathematician, in 1636, mea ing philosophical event cannot but be sured a degree of the meridian with useful as well as entertaining. In the fufficient precision; but this work, mean time we lhall close this essay though accomplished thirty years be by taking a short view of the present fore, was unknown to Newton. The state of philosophical knowledge. civil wars which had troubled the Eng- Natural Philofophy in its present lish nation, and which are always as state admits of two principal divisions, pernicious to the sciences as to the namely, into mechanical and chemical. Itate, had buried in oblivion the only These divifions seem to be merely resneasure of the earth which could be lative to the state of our knowledge. depended on, and the false estimate of The mechanical part of Natural Philo. navigators continued still to be made fophy is the doctrine of such motions use of. From this account the moon as take place among masses of sensible was found to be ton near the earth, magnitude. It therefore includes me. and the proportions enquired after by chanics properly so called, physical Newton did not turn out exact. He astronomy, and hydrostatics. The chedid not think himself ac liberty to sup- mical part is conversant with such mo. ply any thing, or to accommodate na- tions as take place among mailes too ture to his own ideas; but, on the small to come under the senses. We contrary, was ftudious to adjust his do not mention the metaphysical part ideas to the ftandard of nature. He, of Natural Philosophy, the business of therefore, abandoned this capital dif- which is to enquire into the origin of covery, which the analogy of the other the properties of bodies, because it is al. heavenly bodies rendered so highly most certain that the information necessaprobable, and which wanted fo little ry for researches of this nature is placed of being demonftrated. An instance beyond our reach. Now, the mechaof candour which is very rare, and nical department is almost all dependant which alone is enough to add the great- on very few first principles, and admits eit force to his opinions.

of demonstrations built upon those But at length more exact measures data. On these accounts it is in a state were taken in France, and the demon- of very high improvement. But the ftration of this theory was one of the chemical philosophy has not only the confequences. A degree of the meri- disadvantage of its agents being placed dian was settled at twenty-five French out of the reach of sense, but likewise leagues; the dittance of the moon is labours under that of not having been about sixty semi-diameters of the earth, in the hands of men of science till of and from these data it was easy to late years. · thew that the gravitating force of the The cultivators of this science may moon towards the earth, when com- be classed from the relation their pare pared with that of a body at the earth's suits have to these several branches. furface, is in the inverted ratio of the Metaphysics is at present very little atsquares of the distances from the center. tended to, and even very imperfectly Lond. Mag. Aug. 1783.

under

understood in general. Men of real chine, and he among them that can genius seem to think it too unprofitable get the longest spark is reckoned the a field to attempt its cultivation, and greatest philosopher. In proportion the books published on the subject, if as their pretenfions to science are weak we except those of Locke, Hartley, they attach the higher idea of exceland a very few others on the human lence to things of small importance. understanding, are nothing more than 'The ufe of a new varnish, the bending an occafional reviving of the superficial of a wire, or the facility in using a opinions which the wanderings of the hamıner, file, pincers, or blow-pipe, mind have produced in all cutivated are celebrated by these gentlemen in ages, and which consequently may be very pompous ftrains, there being a found in the writings of the ancients. Sori of mutual agreement among them We may, therefore, divide philoso- to congratulate each other on their phers into theorists, empirics, and true happy discoveries. It is with relucphilosophers.

tance that we are under the neceflity ... The age when the invention of the- of including a considerable number of ories, by which in this place we mean chemists in this class. We shall, there. to imply hypotheses, met with the fore, proceed to the true philosopher. greatelt encouragement was that in The true philofopher is he who pofwhich philosophical liberty was in a selles abilities, industry, and literature. great measure restored to Europe by Since every thing in nature is performthe destruction of the empire of Arifto-ed by motion, it is absolutely neceftle. But there have been and eversary he should be deeply skilled in mawill be a considerable number of men, thematical science; and because in exwho, supposing themselves to possess periments the cause is usually very regenius, are willing to display it by a mote from the effect, his imagination folution of those difficulties that more should be lively, his habits of reasonknowing or more modeft enquirersing quick and accurate, and above all, have left to the investigation of futu- his mind free from the influence of rity. These men imagine genius to prejudice. Perfections which rarely consist in a certain inspiration or inde- center in one person, but when they finable faculty that confers the power do, they render him a blessing to manof excelling others without that labour kind, and an ornament to his age and to which common minds must submit. nation. Such a man will be without But genius, in fact, can be nothing arrogance, for he has ikill to see his else but mental strength, and it is in own imperfections. He will be affavain for the possessor of strength to ex- ble, mild, and patient in conversation, pect to go beyond others by any means for he knows that the discourse of the besides that of exerting himself. An most ignorant may sometimes afford occasional work by writers of this facts of the most interesting nature. class appears now and then among us; He will be jutt, benevolent, and finbut as they generally display their ig- cere, for he is enamoured of truth. norance of the first principles of that Even in the midst of the most successphilosophy they attempt to confute, ful research, when he begins to enjoy their works remain in oblivion, and that Supreme delight which arises from are treated with too much contempt to discovery, he will never fuffer himself receive even an answer by those who to be seduced by the delusions of fancy. are capable of making the easy con- All his productions will be chaste, acquest. It will readily be imagined that curate, perspicuous, and important. this class of philosophers, it they may 'His reward awaits him; for he is en he so named, are of no use to fciénce.'. titled to consider himself as the bene.

The empirics are a set of ingenious factor of the world, and can fit down men, who receive vast amusement hy with the fatisfaction of saying, I have ebrau ing sparks from an electrical ma- done my duty,

NATL'RAL

2

NATURAL HISTORY.
From the PHILOSOPHICAL TRANSACTIONS, Vol. LXXII. Part II.

for the Year 1782.
ACCOUNT OF THE ORGAN OF HEARING IN FISH.

BY JOHN HUNTER, Esq. F. R. S.

Read Nov. 14, 1782.
NATURAL History has ever been

As I do not intend to give, in this paper, a full account of this

organ

in tion of the curious philosopher, and any one fish, or of the varieties in diftherefore has in all ages kept pace with ferent fish, but only of the organ in the other branches of knowledge; and general, those, who may choose to puras both arts and sciences have, of late sue this part only of the animal coyears, been cultivated to a degree, per. nomy, may think it deficient in the dehaps, beyond what was ever known scriptive parts. If it was a difficult before, we find also, that Natural Hif- talk to expose this organ in fish, I Mould tory has not been neglected; all Europe perhaps be led to be more full in my appears to be awake to it. In this description of it, but there is nothing illand it has been pursued with more more easy than the exposure of this orphilosophic ardour chan what was ever gan in this animal in general. known in any country. It has become As this paper is to be confined to the study of men of independent for this order of animals, I may be allowed tunes, who not only spend their for- just to observe here, that the class caltunes in the cultivation of this science, led sepia has this organ also, but somebut have risqued their health and lives what differently constructed from what in parsuit of it, searching unknown it is in the filh. regions to improve mankind, fertling The organ. of hearing in ghis latter correspondences every where, so as to order of animals are placed on the sides bring in its materials into this country, of the skull, or that cavity which conin order to make it the school of Na- tains the brain; but the skull itself tural History. It is no wonder, then, makes no part of the organ, as it does that a spirit of inquiry is diffused in the quadruped and the bird. In through almost all ranks of men; and some fish this organ is wholly furroundthat though many cannot pursue ited by the parts composing this cavity, themselves, yet they are eager to know which in many is cartilaginous, the what is already known, choosing at skeleton of these fish being like those leaft to benefit by the industry of others. of the ray kind; in others also, as in

These reflections have induced me çod, salmon, &c. whose skeleton is to trouble this learned Society with a bone, yet this part is cartilaginous. hort account of the Organ of Hearing In fomne fish this organ is in part in Fish, it being still a subject of great within the cavity of the skull, or that dispute, whether filh hear or not. farity which also contains the brain,

Some time between the years 1750 as in the falmon, cod, &c. the cavity and 1760, I observed the organ of of the full projecting laterally, and hearing in filh; and from that time to forming a cavity there, this, I only considered it as a link in The organ of hearing in fish appears the chain of the varieties in this sense to grow in size with the animal, for in different animals, in which there is its size is nearly in the same propora regular progrellion, viz. from the tion with the size of the animal, which most perfect animals down to the most is not the case with the quadruped, &c. imperfect possessed of this organ*. the organs being in thein nearly as large

P 2 * Preparations to illustrate these facts have been ever since shewn, in my collection, to the curious both of this country and foreigners: when, in Thewing whatever was new, or supposed to be acw, inc ears of fish were always considered by me as one important article.

in

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in the growing fætus as in the unite with the other two arms of the aduit.

perpendicular near the entrance into the It is much more fimple in fish than common canal or cavity. in all those orders of animals who may Near the union of those canals inbe reckoned superior, such as quadru- to the common, they are swelled out peds, birds, and amphibious animals, into round bags, becoming there much but there is a regular gradation from larger. the first to fish.

In the ray kind they all terminate in It varies in different orders of fish; one cavity, as has been observed; and but in all it consists of three curred in the cod they terminate in one canal, tubes, all of which unite with one ano- which in these fish is placed upon the ther; this union forms in some only a additional cavity or cavities. In this canal, as in the cod, falmon, ling, &c. cavity or cavities there is a bone or and in others, a pretty large cavity as bones. In some there are two bones ; in the ray kind." In the jack there is as the jack has two cavities, we find in an oblong bag, or blind process, which one of those cavities two bones, and in is an addition to those canals, and the other only one; in the ray there is which communicates with them at their only a chalky substancet. union. In the cod, &c. this union of At this union of the two perpendithe three tubes ftands upon an oval ca- culars in some filh enters the external vity, and in the jack there are two of communication, or what may be called those cavities; these additional cavities the external meatus. This is the case in these fish appear to answer the same with all the ray kind, the external ori. purpose with the cavity in the ray or fice of which is small, and placed on cartilaginous fiin, which is the union the upper flat surface of the head; but of the three canals.

it is not every genus or species of fish The whole is composed of a kind of that has the external opening. cartilaginous substance, very hard or The nerves of the ear pass outwards firm in some parts, and which in fome from the brain, and appear to termifilm is crusted over with a thin bony nate at once on the external surface of lamella, so as not to allow them to col- the fwelling of the semi-circular tubes japse; for as the full does not form above described. They do not appear any part of those canals or cavities they to pass through those tubes so as to get must be composed of such fubftance as on the inside, as is supposed to be the is capable of keeping its form. case in quadrupeds; 1 fhould, therefore,

Each tube deferibes more than a fe. very much suspect, that the lining of mi-circle. This resembles in some re- those tubes in the quadruped is not spect what we find in most other ani- nerve, but a kind of internal periosteum. mals, but differs in the parts being di- As it is evident that fish posless the ftinct from the skull*.

organ of hearing, it becomes unnecefTwo of the semi-circular canals are fary to make or relate any experiment fimilar to one another, may be called a made with live fish which only tends pair, and are placed perpendicularly; to prove this fact; but I will mention the third is not fo long; in some it is one experiment, to few that sounds placed horizontally, uniting as it were affect them much, and is one of their the other two at their ends or termina- guards, as it is in other animals, In tions. In the skait it is something dif- the year 1762, when I was in Portugal, ferent, being only united to one of the I observed in a nobleman's garden, perpendiculars.

near Lisbon, a small fish-pond, full of The two perpendiculars unite at one different kinds of fish. Its bottom was part in one canal, by one arm of each level with the ground, and was made uniting, while the other two arms or by forming a bank all round. There horns have no connection with each was a fhrubbery close to it. Whilft I other, and the arms of the horizontal was lying on the bank, observing the

fish * The turde and the crocodile have a structure fomewhat similar to this; and the intention is the

fame, for their skulls make no part of the organ.
+ This chalky subítance is also found in the ears of amphibious animals.

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