GREGORY

GREGORY (David), Savilian professor of astronomy at Oxford, whom Dr Smith has termed subtilissimi ingenii mathematicus, was the eldest son of Mr Gregory of Kilmairdy, brother of the above mentioned Mr James Gregory. He was born at Aberdeen in 1661, and received the earlier parts of his education in that city. He completed his studies at Edinburgh; and, being possessed of the mathematical papers of his uncle, soon distinguished himself likewise as the heir of his genius. In the 23d year of his age, he was elected professor of mathematics in the university of Edinburgh; and published, in the same year, Exercitatio Geometrica de dimensione figurarum, seu specimen methodi generalis dimetendi quosvis figuras, Edinburgh, 1684, 4to. He saw very early the excellence of the Newtonian philosophy; and had the merit of being the first who introduced it into the schools by his public lectures at Edinburgh. "He had (says Mr Whiston*) already caused several of his scholars to keep acts, as we call them, upon several branches of the Newtonian philosophy; while we at Cambridge, poor wretches, were ignominiously studying the fictitious hypotheses of the Cartesian."

In 1691, on the report of Dr Bernard's intention of resigning the Savilian professorship of astronomy at Oxford, David Gregory went to London; and being patronised by Sir Isaac Newton, and warmly befriended by Mr Flamstead the astronomer royal, he obtained the vacant professorship, for which Dr Halley was a competitor. This rivalry, however, instead of animosity, laid the foundation of friendship between these eminent men; and Halley soon after became the colleague of Gregory, by obtaining the professorship of geometry in the same university. Soon after his arrival in London, Mr Gregory had been elected a fellow of the royal society; and, previously to his election in-

to the Savilian professorship, had the degree of doctor of physic conferred on him by the university of Oxford (a).

In 1693, he published in the Philosophical Transactions a resolution of the Florentine problem de Testudine veliformi quadrabili; and he continued to communicate to the public, from time to time, many ingenious mathematical papers by the same channel. In 1695, he printed at Oxford Catoptrica et Dioptrica Sphaerica Elementa; a work which, as he informs us in his preface, contains the substance of some of his public lectures read, eleven years before, at Edinburgh. This valuable treatise was republished first with additions by Dr William Brown, with the recommendation of Mr Jones and Dr Desaguliers; and afterwards by the latter of these gentlemen, with an appendix containing an account of the Gregorian and Newtonian telescopes, together with Mr Hadley's tables for the construction of both those instruments. It is not unworthy of remark, that, in the end of this treatise, there is an observation which shows, that what is generally believed to be a discovery of a much later date, the construction of achromatic telescopes, which has been carried to great perfection by Mr Dollond and Mr Ramsden, had suggested itself to the mind of David Gregory, from the reflection on the admirable contrivance of nature in combining the different humours of the eye. The passage is as follows: "Quod si ob difficultates physicas in speculis idoneis torno elaborandis et poliendis, etiamnum lentibus uti oporteat, fortassis media diversie densitatis ad lentem objectivam componendam adhibere utile foret, ut a natura factum observamus in oculi fabrica, ubi cristallinus humor (fere ejusdem cum vitro virtutis ad radios lucis refringendos) aqueo et vitreo (aqueo quoad refractionem haud absimilibus) conjungitur, ad imaginem quam distincte fieri poterit, a natura nihil frustra moliente, in oculi fundo depingendam." Catopt. et Dioptr. Sphaer. Elem. Oxon. 1695, p. 98.

In 1702 our author published at Oxford, Astronomiae Physicae et Geometricae Elementa; a work which is accounted his master-piece. It is founded on the Newtonian doctrines, and was esteemed by Sir Isaac Newton himself as a most excellent explanation and defence of his philosophy. In the following year he gave to the world an edition in folio of the works of Euclid in Greek and Latin; in prosecution of a design of his predecessor Dr Bernard, of printing the works of all the ancient mathematicians. In this work, although it contains all the treatises attributed to Euclid, Dr Gregory has been careful to point out such as he found reason, from internal evidence, to believe to be the productions of some inferior geometrician. In prosecution of Dr Bernard's plan, Dr Gregory engaged, soon after, with his colleague Halley,

Gregory. in the publication of the Conics of Apollonius; but he had proceeded but a little way in this undertaking when he died, in the 49th year of his age, at Maidenhead in Berkshire, A. D. 1710. To the genius and abilities of David Gregory, the most celebrated mathematicians of the age, Sir Isaac Newton, Dr Halley, and Dr Keill, have given ample testimonies. Besides those works published in his lifetime, he left in manuscript, A Short Treatise of the Nature and Arithmetic of Logarithms, which is printed at the end of Dr Keill's translation of Commandine's Euclid; and a Treatise of Practical Geometry, which was afterwards translated, and published in 1745, by Mr Maclaubin.

Dr David Gregory married, in 1695, Elisabeth, the daughter of Mr Oliphant of Langtown in Scotland. By this lady he had four sons, of whom, the eldest, David, was appointed regius professor of modern history at Oxford by king George I. and died in 1767, in an advanced age, after enjoying for many years the dignity of dean of Christ church in that university.

Gregory (Dr John), professor of medicine in the university of Edinburgh, was the son of Dr James Gregory professor of medicine in King's college Aberdeen, and grandson of James the inventor of the Gregorian telescope. His father was first married to Catharine Forbes, daughter of Sir John Forbes of Monymusk; by whom he had six children, most of whom died in infancy. He married afterwards Anne Chalmers, only daughter of the Rev. Mr George Chalmers principal of King's college, by whom he had two sons and a daughter. John, the youngest of the three, was born at Aberdeen, June 3. 1724. Losing his father when only in the 7th year of his age, the care of his education devolved on his grandfather Principal Chalmers, and on his elder brother Dr James Gregory, who, upon the resignation of their father a short time before his death, had been appointed to succeed him in the professorship of medicine in King's college. He likewise owed much in his infant years, and during the whole course of his studies, to the care and attention of his cousin, the celebrated Dr Reid, now of the university of Glasgow. The rudiments of our author's classical education he received at the grammar-school of Aberdeen; and, under the eye of his grandfather, he completed, in King's college, his studies in the Latin and Greek languages, and in the sciences of ethics, mathematics, and natural philosophy. His master in philosophy and in mathematics was Mr Thomas Gordon, the present philosophy professor of King's college, who has ably filled an academical chair for above half a century.

In 1742, Mr Gregory went to Edinburgh, where the school of medicine was then rising to that celebrity which has since so remarkably distinguished it. Here he attended the anatomical lectures of the elder Dr Monro, of Dr Sinclair on the theory of medicine, and of Dr Rutherford on the practice. He heard likewise the prelections of Dr Allston on the materia medica and botany, and of Dr Plummer on chemistry. The medical society of Edinburgh, instituted for the free discussion of all questions relative to medicine and philosophy had begun to meet in 1737. Of this society we find Mr Gregory a member in 1742, at the time when Dr Mark Akenfide, his fellow student, and

intimate companion, was a member of the same institution.

In the year 1745 our author went to Leyden, and attended the lectures of those celebrated professors Gaubius, Albinus, and Van Royen. While at this place he had the honour of receiving from the King's college of Aberdeen, his alma mater, who regarded him as a favourite son, an unfolicited degree of doctor of medicine; and soon after, on his return thither from Holland, he was elected professor of philosophy in the same university. In this capacity he read lectures during the years 1747, 1748, and 1749, on mathematics, on experimental philosophy, and on moral philosophy. In the end of 1749, however, he chose to resign his professorship of philosophy, his views being turned chiefly to the practice of physic, with which he apprehended the duties of this professorship, occupying a great portion of his time, too much interfered. Previously, however, to his settling as a physician at Aberdeen, he went for a few months to the Continent; a tour of which the chief motive was probably amusement, though, to a mind like his, certainly not without its profit in the enlargement of ideas, and an increased knowledge of mankind.

Some time after his return to Scotland, Dr Gregory married, in 1752, Elisabeth daughter of William Lord Forbes; a young lady who, to the exterior endowments of great beauty and engaging manners, joined a very superior understanding, and an uncommon share of wit. With her he received a handsome addition of fortune; and during the whole period of their union, which was but for the space of nine years, enjoyed the highest portion of domestic happiness. Of her character it is enough to say, that her husband, in that admired little work, A Father's Legacy to his daughters, the last proof of his affection for them, declares, that, "while he endeavours to point out what they should be, he draws but a very faint and imperfect picture of what their mother was." The field of medical practice at Aberdeen being at that time in a great measure pre-occupied by his elder brother Dr James Gregory, and others of some note in their profession, our author determined to try his fortune in London. Thither accordingly he went in 1754; and being already known by reputation as a man of genius, he found an easy introduction to many persons of distinction both in the literary and polite world. The late George Lord Lyttleton was his friend and patron. An attachment, which was founded on a striking similarity of manners, of tastes, and of dispositions, grew up into a firm and permanent friendship; and to that nobleman, to whom Dr Gregory was wont to communicate all his literary productions, the world is indebted for the publication of the Comparative View of the State and Faculties of Man, which made him first known as an author. Dr Gregory likewise enjoyed the friendship of the late Edward Montague, Esq; and of his lady, the celebrated champion of the Fame of Shakespeare against the cavils and calumnies of Voltaire. At her assemblies, or conversazione, the resort of taste and genius, our author had an opportunity of cultivating an acquaintance with many of the most distinguished literary characters of the present times.

In 1754 Dr Gregory was chosen fellow of the roy-

Gregory. al society of London; and, daily advancing in the public esteem, it is not to be doubted, that, had he continued his residence in that metropolis, his professional talents would have found their reward in a very extensive practice. But the death of his brother, Dr James Gregory, in November 1755, occasioning a vacancy in the professorship of physic in King's college, Aberdeen, which he was solicited to fill, he returned to his native country in the beginning of the following year, and took upon him the duties of that office to which he had been elected in his absence.

Here our author remained till the end of the year 1764, when, urged by a very laudable ambition, and presuming on the reputation he had acquired as affording a reasonable prospect of success in a more extended field of practice, he changed his place of residence for Edinburgh. His friends in that metropolis had represented to him the situation of the college of medicine as favourable to his views of filling a professorial chair in that university; which accordingly he obtained in 1766, on the resignation of Dr Rutherford professor of the practice of physic. In the same year he had the honour of being appointed first physician to his majesty for Scotland on the death of Dr Whytt.

On his first establishment in the university of Edinburgh, Dr Gregory gave lectures on the practice of physic during the years 1767, 1768, and 1769. Afterwards, by agreement with Dr Cullen, professor of the theory of physic, these two eminent men gave alternate courses of the theory and of the practice.—As a public speaker, Dr Gregory's manner was simple, natural, and animated. Without the graces of oratory, which the subject he had to treat in a great degree precluded, he expressed his ideas with uncommon perspicuity, and in a style happily tempered between the formality of studied composition and the ease of conversation. It was his custom to premeditate, for a short time before entering the college, the subject of his lecture, consulting those authors to whom he had occasion to refer, and marking in short notes the arrangement of his intended discourse: then fully master of his subject, and confident of his own powers, he trusted to his natural facility of expression to convey those opinions which he had maturely deliberated. The only lectures which he committed fully to writing, were those introductory discourses which he read at the beginning of his annual course, and which are published in these volumes under the title of Lectures on the Duties and Qualifications of a Physician. Of these, which were written with no view to publication, many copies were taken by his pupils, and some from the original manuscript, which he freely lent for their perusal. On hearing that a copy had been offered for sale to a bookseller, it became necessary to anticipate a fraudulent, and perhaps a mutilated publication, by authorising an impression from a corrected copy, of which he gave the profits to a favourite pupil. These lectures were first published in 1770, and afterwards in an enlarged and more perfect form in 1772.

In the same year, 1772, Dr Gregory published Elements of the Practice of Physic, for the use of Students; a work intended solely for his own pupils, and to be used by himself as a text-book to be commented upon in his course of lectures. In an advertisement prefixed

to this work, he signified his intention of comprehending in it the whole series of diseases of which he treated in his lectures on the Practice of Physic; but this intention he did not live to accomplish, having brought down the work no further than to the end of the class of Febrile Diseases.—In his academical lectures, Dr Gregory never attempted to mislead the student by flattering views of the perfection of the science; but was, on the contrary, anxious to point out its defects; wisely judging, that a thorough sense of the imperfection of an art or science is the first step towards its improvement. In this view he was careful to expose the fallaciousness of the several theories and hypotheses which have had the most extensive currency, and perpetually inculcated the danger of systematizing with limited experience, or an imperfect knowledge of facts. Yet in the work last mentioned it will appear, from the order in which he has treated of the several diseases, that he did not entirely neglect the systematic arrangements of other authors. These, however, he warned his pupils, that he had not adopted from any conviction of the rectitude of those theories to which they referred, but only as affording that degree of method, and regularity of plan, which is found to be the best help to the study of any science.

Considering a rational theory of physic to be as yet a desideratum, it was his object to communicate to his pupils the greatest portion of practical knowledge, as the only basis on which such a theory could ever be reared. His method, in treating of the several diseases, was first to mention those symptoms which are understood among physicians to characterise or define a disease; proceeding from the general to the more particular series of symptoms and their occasional varieties; to point out accurately the diagnostic symptoms, or those by which one disease is essentially distinguished from others that resemble it, and to mark likewise the prognostics by which a physician is enabled to conjecture of the probable event of a disease, whether favourable or otherwise. He then proceeded to specify the various causes, predisposing, occasional, and proximate; accounting, as far as he thought could be done on just principles, for the appearance of the several symptoms; and, finally, he pointed out the general plan of cure, the particular remedies to be employed, and the cautions requisite in the administration of them. Thus desirous of establishing the science of medicine upon the solid foundation of practice and experience; and knowing that many things asserted as facts by medical writers have been assumed on a very careless observation, while confirming a favourite theory; and that, on the other hand, many real and important facts have, from the same spirit of system, been explained away and discredited; he constantly endeavoured, both by his precept and example, to inculcate to his pupils the necessity of extreme caution either in admitting or in denying medical facts, or what are commonly given as such. To the desire of enforcing this necessary caution is owing that multitude of queries respecting matters of fact, as well as matters of opinion, which occurs in the Elements of the Practice of Physic.

Dr Gregory, soon after the death of his wife, and, as he himself says, "for the amusement of his solitary hours,"

Gregory. hours," employed himself in the composition of that admirable tract, intitled, A Father's Legacy to his Daughters, a work which, though certainly never intended by its author for the public eye, it would have been an unwarrantable diminution of his fame, and a capricious refusal of a general benefit to mankind, to have limited to the sole purpose for which it was originally designed. It was, therefore, with great propriety, published after the author's death by his eldest son. This work is a most amiable display of the piety and goodness of his heart, and his consummate knowledge of human nature and of the world. It manifests such solicitude for their welfare, as strongly recommends the advice which he gives. He speaks of the female sex in the most honourable terms, and labours to increase its estimation, whilst he plainly, yet gently and tenderly, points out the errors into which young ladies are prone to fall. It is particularly observable, in what high and honourable terms he speaks of the Holy Scriptures, of Christian worship, and faithful ministers; how warmly he recommends to his daughters the serious and devout worship of God in public and private. He dwells largely on that temper and behaviour, which were particularly suited to their education, rank, and circumstances; and recommends that gentleness, benevolence, and modesty, which adorn the character of the ladies, and do particular honour to their sex. His advice, with regard to love, courtship, and marriage, are peculiarly wise, and interesting to them. They show what careful observation he had made on female domestic conduct, and on the different effects of possessing or wanting the virtues and qualities which he recommends. There is something peculiarly curious, animated, and useful, in his directions to them, how to judge of, and manifest an honourable passion in, and towards the other sex, and in the very accurate and useful distinction which he makes between true and false delicacy. Nothing can be more striking and affecting, nothing more likely to give his paternal advice its desired effect, than the respectful and affectionate manner in which he mentions his lady their mother, and the irreparable loss which he and they sustained by her early death. In short, in this tract, the professor shines with peculiar lustre as a husband and father, and it is admirably adapted to promote domestic happiness.

These letters to his daughters were evidently written under the impression of an early death, which Dr Gregory had reason to apprehend from a constitution subject to the gout, which had begun to show itself at irregular intervals even from the 18th year of his age. His mother, from whom he inherited that disease, died suddenly in 1770, while sitting at table. Dr Gregory had prognosticated for himself a similar death; an event of which, among his friends, he often talked, but had no apprehension of the nearness of its approach. In the beginning of the year 1773, in conversation with his son the present Dr James Gregory, the latter remarking, that having for the three preceding years had no return of a fit, he might make his account with a pretty severe attack at that season; he received the observation with some degree of anger, as he felt himself then in his usual state of health. The prediction, however, was too true; for having gone to bed on the 9th of February 1773, with no

apparent disorder, he was found dead in the morning. His death had been instantaneous, and probably in his sleep; for there was not the smallest discomposure of limb or of feature,—a perfect Euthanasia.

Dr Gregory, in person, was considerably above the middle size. His frame of body was compacted with symmetry, but not with elegance. His limbs were not active; he stooped somewhat in his gait; and his countenance, from a fullness of feature and a heaviness of eye, gave no external indication of superior power of mind or abilities. It was otherwise when engaged in conversation. His features then became animated, and his eye most expressive. He had a warmth of tone and of gesture which gave a pleasing interest to every thing which he uttered: But, united with this animation, there was in him a gentleness and simplicity of manner, which, with little attention to the exterior and regulated forms of politeness, was more engaging than the most finished address. His conversation flowed with ease; and, when in company with literary men, without affecting a display of knowledge, he was liberal of the stores of his mind. He possessed a large share of the social and benevolent affections, which, in the exercise of profession, manifested themselves in many nameless, but important, attentions to those under his care; attentions which, proceeding in him from an extended principle of humanity, were not squared to the circumstances or rank of the patient, but ever bellowed most liberally where they were most requisite. In the care of his pupils, he was not fatigued with a faithful discharge of his public duties. To many of these, strangers in the country, and far removed from all who had a natural interest in their concerns, it was matter of no small importance to enjoy the acquaintance and countenance of one so universally respected and esteemed. Through him they found an easy introduction to an enlarged and elegant society; and, what to them was still more valuable, they experienced in him a friend who was ever easy of access, and ready to assist them to the utmost with his counsel and patronage.—The same spirit of philanthropy endeared him in a particular manner to his intimate friends; among whom may be ranked most of the Scottish literati of his time.—Some time after his death, the professorship of the Theory of Medicine was bellowed upon his eldest son the present Dr James Gregory; who has since succeeded to the Practical Chair, lately filled by that other most eminent professor Dr Cullen.