He employs, for this purpose, two achromatic prisms, to which he gives (the one upon the other) a circular motion: these will therefore reprefent fucceffively all prifms, from the plane to the prifm, whofe angle is the double of that of each prifm; thus the obferver, viewing the fame object, at the fame time, directly and through this prifm, and turning the prifm till it comes to the point where the two images of the object will only touch one another, the angle of the prifm will then give the apparent diameter of the object. The accuracy of the inftrument here, depends upon the means of knowing exactly the angle of a given prifm, and the Abbé ROCHON has found out means for this end, whofe precifion and efficacy may be entirely depended upon. A defcription of thefe inftruments was read by the Abbé to the Royal Academy in the year 1777, fo that, though the Author has neither publifhed as yet the conftruction, nor the different ufes of his inftruments, they may be confidered as known to the public fince that epocha. This is a good caveat against fuch as may be difpofed to ufurp the merit of other men's inventions.

The part of this volume, that is confecrated to the memory of deceafed academicians, contains the Eulogies of four men, eminent, indeed, for their talents and their virtues: Meffieurs, Trudaine, De fuffieu, Bourdelin, and Haller. Many amiable and interefting lines might be presented to our readers from the characters of thefe illuftrious men; but want of space obliges us to confine ourselves to fome particularities of the life and genius of the late M. HALLER, Member of the Sovereign Council at Bern, and of all the academies of Europe, who may be juftly confidered as one of the prodigies of the prefent age.

He was born of a family, where piety feemed to be hereditary, and, at four years of age, he ufed to addrefs exhortations from texts of fcripture to his father's domeftics. "At the age of NINE, he had compofed, for his own ufe, a Chaldaic Grammar, a Hebrew and Greek Lexicon, and an Hiftorical Dictionary, containing near two thoufand articles, extracted from Bayle and Mareri. The care taken of his education had no part in this monstrous progrefs; he had a fevere and disgusting preceptor, who had made fuch impreffions on his mind at this early period, that he never met him, in riper years, without feeling an involuntary emotion of terror. He was born a poet, and had a paffion for this fine art, which he exercised with all the fuccefs, that attends true taste and elevated genius, and with which he embellished and softened his philofophical labours. The ftudy of nature was, however, his great and predominant propenfity, and it was with a view to gratify it, that he chofe the medical profeffion, which allowed him to pursue this study

without

without reftraint. He ftudied at Tubingen, under Camerarius and Duvernoi; at Leyden, under Boerhaave and Albinus; at London he enjoyed the intimacy of Sir Hans Sloane, Chefelden, and Douglas; and at Paris he followed the directions of Winflow and Juffieu. He began to travel at the age of fixteen, and at that dangerous and critical period, he was confirmed for the reft of his life in the paths of virtue, by the disgust which he felt once, at a view of the excefs committed in a licentious party of pleasure into which his fellow-ftudents had drawn him at Tubingen. From that period he never tafted wine any more, and impofed upon himself a fevere difcipline with respect to morals. His lively imagination, and warm feelings, rendered this difcipline wife and expedient.

M. HALLER returned to Switzerland about the year 1730, in the 22d year of his age. The practice of phyfic, vaft anatomical enterprizes and labours, excurfions into the mountains of Switzerland, where he extended his ardent attention to all the branches of natural history, all these were not fufficient to fill up his time. His mufe invited him to ftrike the lyre amidft the beautiful and magnificent scenes of nature. But the philofopher always accompanied the poet, and kept him in the arms of real nature. He defcribed what he faw, when he climed rocks of eternal ice, and traverfed the awful fummits of the Alpine mountains. He defcribed what he felt, when he painted the sweets of friendship and of rural life, the pleasures that accompany fimplicity of manners, the charms of the mild and gentle virtues, and the happiness that flows from the facrifices that are required by the more auftere. His muse even founded the depth of metaphyfical and moral fcience; fhe fung alfo the fublime delights of religion, and its genuine fruits, charity, and concord, and drew the hideous forms of hypocrify and perfecution in the most odious and natural colours. The poems of HALLER were foon tranflated into almoft all the European languages, and the poets, and wits of the age, were furprized to learn, that thefe elegant and fublime compofiions, came from the pen of a man, who paffed his days in diffecting bodies, culling plants, and prying into the fecrets of animal and vegetable organization. The philologifts and antiquarians must have been equally furprized, at least, to find this two-fold fon of Apollo, while he was teaching anatomy, and directing a famous hofpital at Bern, at the age of 26, charged with the inspection of the public library, and the arrangement of a cabinet of five thousand ancient medals.

His reputation grew rapidly, and was spread abroad, though not yet diftinguifhed by any great work in the line of his profeffion. Several differtations had announced him, however, to anotomifts, as a young man of fuperior genius, when George

2

George II. honoured him with an invitation to the univerfity of Gottingen, where a chair of anatomy, botany, and surgery was erected for him. Here he paffed 17 years of his life in the moft intense application to ftudy, and found his labours alleviated by the pleasure which a generous mind must feel from diftinguished fuccefs and univerfal applaufe. His principal object was phyfiology, that important branch of medical science, which, confidering the ftructure of the body in its minuteft parts, examines the laws by which the human being is formed, developed, grows, lives, propagates, declines, and dies,-how each organ performs its functions and repairs its ftrength by nourishment and fleep, by what mechanism an unknown power produces thofe voluntary and involuntary motions, that are effential to the exiftence, prefervation, and happiness of man,-how the changes in the bodily organs are sometimes the caufe, and fometimes the effect of the diforder of the vital functions, and how remedies of every kind may contribute, by their action on these organs, to restore order in the animal economy. M. HALLER brought about a fignal and happy revolution in phyfiological fcience, which had long been subjected to the tyranny of fyftem, and became, on that account, an object of fufpicion and diffidence to the Philofophical Obferver of Nature. He propofed to fhew that phyfiology was a fcience as real and certain as any other ;-the key of the knowledge of man to the philofopher, and the bafis of medical practice to the phyfician. For this purpose he established physiology on its true foundations, on the anatomy of the human body, and on that of other animals, which latter has fo often revealed fecrets in the conftitution of man, that the ftudy of the human body alone would not have discovered. He banished from it that kind of metaphyfics, which had long concealed profound ignorance under the cover of fcientific terms, and thofe theories, whether mathematical or chemical, which were employed with the moft confidence, and adopted with the moft refpect, by those who were the most ignorant of mathematics and chemistry. In the place of all these fyftems and theories, he fubftituted general facts afcertained by obfervation and experience; and, to prepare himself for embracing the fcience of phyfiology in all its extent, he compofed a long feries of differtations, in which he discussed the niceft, the most difficult and important queftions, relative to refpiration, the circulation of the blood, generation, and offification. After all these labours, he gave the first edition of his phyfiology, the modeft title of a Sketch, and it was only at the end of thirty years, employed in the most laborious diffections, experiments, and researches, that he ventured to give his work the title it deferved. All the learned, in all countries, know the merit of this immortal work; they know the multitude of

errors

errors it has removed, the new facts it has difcovered, the ingenious and extenfive views with which it abounds, the doubts it has cleared up, and the theories it has rectified or improved.

But the labours which perhaps contributed moft to establish the fame of M. HALLER, as one of the firft men of his age in philofophical genius, were his researches into the mysteries of generation, offification, and irritability. Here he appears with all the luftre of an original obferver and thinker, who opens for himself paths of investigation untrod before, and follows a lamp that is lighted only by his own genius. But while he was fo ardent and fuccefsful in the discovery of curious and important truths, the nature of his experiments expofed him to mistakes, and feveral of thefe he candidly acknowledged: he even placed at the head of one of his works a compass for a device, with this motto, Fidem non abftulit error. This fhewed his candour, and at the fame time his juft confidence in the refult of his labours. It would fwell this extract to an undue length, even to enumerate fimply the different branches of study and objects of literature that occupied this great man at the fame time, during his refidence at Gottingen; where in confequence of his intereft with the late king, he founded an academy of sciences, a feminary for furgery, a lying-in hofpital, a fchool for drawing or defigning, and other eftablishments. for the improvement of science, and the relief of humanity.

In the year 1753, M. Haller returned to Bern, where he was chofen member of the fovereign council, and thus entered upon a new scene. In the sphere of magiftracy he appeared with dignity and reputation; and in the adminiftration of the government and police of that republic he was more especially employed in those branches which require the fpirit of a philofopher, and the knowledge of nature. Public education, orphan-houses, establishments for promoting the health of the citizens and peasants, particularly the Council of Health formed at Bern, the fuperintendence of the falt-works; all thefe and other objects of police and public utility, were under the more immediate infpection and influence of this patriotic and philofophical magiftrate. Amidft the laborious and useful occupations they gave him, he ftill found leifure for ftudy and writing: for it was amidst thefe occupations that he composed and published a regular fyftem of political economy, in three productions, which have the form of romances, but convey inftructive views of fovereignty in monarchical, mixed, and ariftocratical governments. It was alfo during these occupations that he completed his phyfiology, compofed, in an excellent ftile, a great number of anatomical and medical articles for the Encyclopedie of Paris, and continued to fend Memoirs to all the

learned academies of Europe of which he was a member.

The Academy of Sciences (fays our panegyrift) inferted feveral of these into its collection, and the fe would have been fufficient materials for the eulogy of any man but HALLER."

His activity was unexampled; his library was a perpetual fcene of inftruction, communicated to his friends, his fellowcitizens, his wife and children, with whom he was furrounded, and who read, converfed, delineated plants and animals under his infpection. After having adorned life and filled time, as we have been seeing, he died with the pious tranquillity of a Chriftian hero: he faw his end approach flowly, and beheld it without either fear or regret. The artery beats no more, faid he, with the utmoft calm, to the phyfician that attended him, and then expired.

ART. III.

Hiftoire de Ruffie, tirée des Chroniques`originales et des meilleurs Hif toriens de la Nation, &c. i. e. A History of Ruffia, drawn from authentic Records, and the best hiftorical Writers of that Nation. By M. L'EVESQUE, Profeffor in the Imperial Corps of Cadets at Petersburgh. 5 Vols. in 12mo, enriched with Two Maps of Eaftern and Western Ruffia. Paris, 1782. Price 15 Livres.

HIS Hiftory is 'recommended to the attention and curio

Tfity of the public by a variety of circumftances. Its Au

thor has refided long in Ruffia, has made himself mafter not only of the modern language of that country, but also of the ancient Sclavonian dialect of that language, and has certainly employed great industry and perfeverance in studying all the various chronicles and records, ancient and modern, that could furnish materials for his work, which is the firft complete hiftory of Ruffia that has been yet published. Prefixed to this useful and inftructive work, we find an account of the true orthography of the Ruffian names of perfons and places, which the Author has followed as far as was practicable;-a critical catalogue of the records and writers that have furnished him with materials;-a learned differtation on the antiquity and religion of the Sclavonians, from whom the modern Ruffians derive principally their origin, and on the palpable analogy which their language bears to that of the ancient inhabitants of Latium.

This valuable hiftory of Ruffia is brought down to the prefent time; and we have no doubt but it will be well received thoughout Europe in general.