modern philofophers, or of natural philofophers, who deduce phyfical principles according to Sir Ifaac Newton's rule of philofophizing, by analyfis from mechanical experiment; and not, after the mode of Ariftotle and the ancients, by Synthefis from abftract fpeculation. Precifion of ideas is doubtlefs of the higheft confequence to feientific inveftigation; but fo alfo is propriety of ideas, and perfpicuity of expreffion. Now the notions of the ancient philofophers, adopted by Mr. Harris, refpecting univerfal and primary forms, however precife in imagination, are applicable to no fact or natural phenomenon their lucidity is rather dazzling than clear, while the expreffion of them is to an experimental philofopher dark as Erebus. To prove at least that Mr. Berington is in the dark amidst all this brightnefs, we need only to advert a little to the lucid precision of his own ideas in the above chapter. "Extenfion," fays he, " that infeparable quality "of all bodies, is itfelf preceeded by fomething as its fource ❝of eduction, without which it would not exift." Extenfion exift! The exiftence of mere extenfion, however infeparable it may be from our idea of body, is certainly merely ideal: unlefs Mr. Berington adopts Dr. K's definition of extenfion, as a fpace defcribed and occupied by a power of expansion, as "the fource or principle of its eduction." In this cafe, indeed, extenfion or space may rank among real beings, and lay claim to phyfical exiftence. In fuch cafe, however, it would in effect be the fame thing as fubftance; and might very properly be confidered as one of the conftituent principles of body. But body cannot be deduced, in the manner pointed out by this writer, from mere extenfion; even if we allow of the fpeculative abfurdity, of faying things exift that are merely ideal. For argument's fake, we will, for a moment, lay afide the natural philofopher, (whofe exclufive province, however, it is to confider this fubject) and take up the metaphyfician; admitting the ideal exiftence of our author's body mathematical; we fay, even in this cafe fuch body is not educible, as he pretends, from the appofition of mere mathematical points. We admit, indeed, that a line is generated by the flowing of a point, a furface by the flowing of a line, and fo forth: but our author fpeaks of the effluxion of a point," and the "placing two or more points in conti guous order," as in effect the fame thing: whereas two or more points cannot be placed in fuch order but by the interpofition of a line between every two. And what is to generate fuch lines ?---Again, it is not the union of a fecond Tine with a first that forms a fuperficies; for if united they would G 2 not not even be two lines but one. Approximated by juxta-pofition, they muft neceffarily be feparated by a fuperficies of fome certain breadth: and what, as before, is to conftitute that fuperficies? Mr. B. miftakes in fuppofing that points are the conftituents of extenfion, as units are the coefficients of number. "Extenfion," he fays, " is an effect arising from "the arrangement of units or points, as number is fuppofed σε to flow from the fucceffion or conjunction alfo of units." But an arrangement is made merely by juxta-pofition; the things ar ranged have a diftinct and separate coexiftence; units may therefore conftitute number: but an unit is an integral and definite term, and it increases number by repetition, not by fucceffion or conjunction: an unit may be fuppofed to be formed by flowing from the point of nullity; but when formed an unit is as truly a number, though it be fingular, as if it were dual or plural. One does not flow into two, nor two into three ; the increafe of numbers is by appofition, and not as before obferved, like extenfion by fluxion; a point in Space does not anfwer to an unit in number; the latter is a quantity, the former no quantity at all. On this fubject of extenfion, our author introduces the conundrum of the Zenonifts, and the pertinent, though filent, answer of the peripatetic Diogenes, to the following demonftration of the impoffibility of motion. "Difputants," fays he, " may quibble eternally about aliquote and proportional parts, certainly there are in every portion of matter, for ever divifible, an actual infinite number of moities, as much diftin guished from each other by extra-pofition, as is, in any number, a feries of contiguous balls ranged lineally in contact with each other; and this infinite number of moities, though diminishing in one uniform fcale, cannot be run over, in a given time, unless an infinite number of units may be counted and exhausted by measure and fupputation. The scale of uniform diminution can never remove this infuperable difficulty against progreffive motion, which arifes not from the mafs, but from the infinite number of divifible parts. Yet the undoubted power, and actual exercise of progreffive motion, are popular truths fo very manifeft, that no man in his fenfes would pretend to contest their reality. If the buffoon Diogenes feriously thought, that to get up and walk was a fufficient refutation of Zeno's reasoning, it only proved that the man had not penetration enough to discover the force of the philofopher's argument." There can hardly be a greater quibble or fallacy invented, than the above propofition, viz. that a finite line cannot be run over in a given time, unlefs an infinite number of units may be counted and exhaufted. There is no common meafure applicable to matter and motion; the parts of the one are coexiftent coexiftent, the other fucceffive: there requires no certain duration to diftinguish between two fucceffive points of time, as there does of extenfion to diftinguish between two points of Space. The buffoon Diogenes, therefore, as Mr. Berington calls him, gave Zeno a very proper reply to his futile argument. Difmiffing, therefore, our author's eduction of body mathematical, we fhall examine into that of his body phyfical, in a future review. W. An Account of the Scarlet Fever and Sore Throat, or Scarlatina The public are much indebted to Dr. Withering for this early and accurate account of a difeafe, which may be faid to be, in a manner, new to the inhabitants of this island; many perfons having already fallen victims to its feverity. The following is a defcription of its moft ufual appearance. "This disease first appeared in Birmingham, about the middle of May, and in the beginning of June was frequently in many of the towns and villages in the neighbourhood. It was preceded by fome cafes of the true ulcerated fore throat, and accompanied in its courfe through the fummer by the chin-cough, the measles, the fmall-pox, and feveral inftances of the true quinfy. *It has, indeed, been faid that motion is as definite and precife in quantity.as extenfion; for that nothing can move without moving with fome determinate ve locity. But this plea is fallacious for what is velocity, but the relation between a certain given time and a certain given space? Now as space, though it may be divided indefinitely into coexiftent parts of fome certain extent, it cannot be divided into mathematical points, so time cannot be divided into coexiftent parts at all; no two fucceffive moments either paffing at the fame time, or yet requiring any certain extent of duration, to diftinguish them from each other. There is, therefore, no comparative relation between the conftituent elements of space and time, although there be fuch a relation between a finite quantity of extenfion and a finite quantity of duration. For motion to have any determinate velocity, it is neceffary that it should defcribe a given space in a given time; but this cannot be done before motion have actually taken place, and fuch fpace is fo described; which is not the cafe at the commencement of fuch motion; which must therefore, of neceffity, commence before any determinate velocity is attained. Celeritas fibi fecit eundo. For, it is to be confidered, that, though the momentum, or force of the impetus generating motion be determinate, the celerity of the motion thereby generated depends on the refiftance of the medium oppofing its direction; which refiftance is at first nothing, and increafes from nothing till it arrives at a maximum, determining the celerity of fuch motion. Increase and diminution may proceed ad infinitum, but not addition and divifion. These must have aliquot parts; which parts obtain in space or extenfion, deferibed by local apposition, but not in time or-succession, described by local motion. "It "It continued in all its force and frequency to the end of Oc. tober, varying however in fome of its. fymptoms as the air grew colder. In the beginning of November it was rarely met with, but towards the middle of that month, when the air became warmer, it increased again, and in fome measure refumed thofe appearances which it poffeffed in the fummer months, but had loft during the cold winds in October. *It affected children more than adults; but feldom occured in the former under two years of age, or in the latter when more than fifty. In children the number of boys and girls that fuffered from it was nearly equal; but in adults the number of female patients confiderably exceeded that of the male; probably because the former were more employed in attendance upon the fick, and confequently more expofed to the infection. "On the first seizure the patients feel an unusual wearinefs, or inaptitude to motion; a dejection of fpirits, and a flight foreness or rather stiffness in the throat; with a fenfe of ftraitnefs in the muscles of the neck and fhoulders as if they were bound with cords. In a few hours chilly fits take place, generally alternating with flushing heat; but at length the heat prevails altogether. The pa ments now complain of flight head-ach, and tranfitory fits of ficknefs. They pafs a reftless night, not fo much from pain, as from want of inclination to fleep. The next day the forenefs in the throat increases, and they find a difficulty in fwallowing, but the difficulty feems lefs occafioned by the pain excited in the attempt, or by the ftraitnefs of the paffage, than by an inability to throw the neceffary mufcles into action. A total difrelish to food takes place, and the fickness frequently arifes to a vomiting. The breathing is fhort and often interrupted by a kind of imperfect figh. The skin feels hot.and dry, but not hard and the patients experience frequent, fmall, pungent pains, as if touched with the point of a needle. Towards evening the the heat and restleffnefs increase; the breathis hot and burning to the lips; thirft makes them with to drink, but the tendency to sicknefs, and the exertions neceffary to frequent deglutitions are fo unpleasant, that they feldom care to drink much at a time. This night is paffed with ftill greater inquietude than the former. In the morning the face, neck, and breast, appear redder than ufual; in a few hours this redness becomes univerfal, and increases to such a degree of intenfity, that the face, body, and limbs, refemble a boiled lobster in colour, and are evidently fwollen. Upon preffure the redness vanishes, but foon returns again. The fkin is fmooth to the touch, nor is there the least appearance of pimples or puftules. The eyes and noftrils partake more or lefs of the general redness ; and in proportion to the intenfity of this colour in the eyes, the tendency to delirium prevails. "Things continue nearly in this ftate for two or three days longer, when the intenfe fcarlet gradually abates, a brown colour fucceeds, and the fkin becoming rough, peels off in fmall branny fcales. Icales. The tumefaction fubfides at the fame time, and the pa tients gradually recover their strength and appetite. During the whole courfe of the fever, the pulfe is quick, finall and uncommonly feeble. The bowels regular in their discharges. The urine finall in quantity, but fcarcely differing in appearance from that of a perfon in health. The fubmaxillary glands are generally enlarged, and rather painful when preffed by the fingers. The tongue is red and moift, at the end and at the fides, but drier in the middle, and more or lefs covered with a yellowish brown mucus. The velum pendulum palati, the uvula, the tonfils, and the gullet as far as the eye can reach, partake the general redness and tumefaction. I never faw any real ulceration in these parts, but fometimes collections of thick mucus, particularly on the back of the oefophagus, greatly refembling the specks or floughs in the putrid fore throat, but these are easily washed away by any common gargle. After the fever ceafes, it is not uncommon to have abfceffes from one or both fides of the neck under the ears, but the matter easily discharges itself through the ruptured teguments, and they heal in a few days without much trouble." Such, fays Dr. Withering, is a picture of the difeafe, and its moft ufual appearance; but it too frequently affumes a much more fatal form. He proceeds, therefore, to defcribe its more uncommon fymptoms both in infants and adults; as well as the peculiarity of its autumnal appearances. On a confequential disease, after the ceffation of the fever, the doctor obferves, that "Happy would it be for the ease of the practitioner, but still more fo for that of the patient, if the baleful influence of the fcarlet fever and fore throat had its termination here. But in ten or fifteen days from the ceflation of the fever, another train of symptoms demands the attention of the former, and exercifes the fufferance of the latter. They feel, after a few days amendinent, a fomething that prevents their further approach to health: an unaccountable languor and debility prevails, together with a stiffness in the limbs, an accelerated pulfe, difturbed fleep, difrelish to food, and a paucity of urine. "These symptoms are foon followed by an univerfal fwelling of the anafarcous kind, and fometimes an afcites. In fome patients the feverish difpofition runs high, in others it exifts only in a moderate degree. In fome the dropfy affects the brain, producing coma-vigil, delirium, blindnefs; with the moft enlarged expanfion of the iris, which is incapable of contraction in the strongest light. In others, the dropfy falls upon the lungs, and produces every fymptom of the true hydrops pectoris. The tongue is dry and brown; the skin harfh; the urine of a deep mahogany colour, fmall in quantity, and depofiting a fediment of a ftill deeper hue, and in a powdery form. "The urgency of these symptoms, added to the very evident appearance of difeafe, foon compel the patients or their friends to apply |