Keill, John

, an eminent mathematician and philosopher, was born Dec. 1, 1671, at Edinburgh, where he received the first rudiments of learning; and, being educated in that university, continued there till he took the degree of M. A. His genius leading him to the mathematics, he studied that science very successfully under David Gregory the professor there, who was one of the first that had embraced the Newtonian philosophy; and, in 1694, he followed his tutor to Oxford, where, being admitted of Baliol, he obtained one of the Scotch exhibitions in that college. He is said to have been the first who taught Newton’s principles by the experiments on which they are grounded, -which he was enabled to do by an apparatus of instruments of his own providing; and the lectures he delivered in his chambers upon natural and experimental philosophy, procured him very great reputation. The first public specimen he gave of his skill in mathematical and philosophical knowledge, was his “Examination of Burnet’s Theory of the Earth,” which appeared in 1698, and was universally applauded by the men of science, and allowed to be decisive against the doctor’s “Theory.” To this piece he subjoined “Remarks upon Whiston’s New Theory of the Earth;” and these theories, being defended by their respective inventors, drew from Keill, in 1699, another performance entitled “An Examination of the Reflections of the Theory of the Earth, together with ‘ a Defence of the Remarks on Mr. Whiston’s New Theory’.” Dr. Burnet was a man of grea.t humanity, moderation, and candour; and it was therefore supposed that Keill had treated him too roughly, considering the great disparity of years between them. Keill, however, left the doctor in possession of that which has since been thought the great characteristic and excellence of his work: and, though he disclaimed him as a philosopher, yet allowed him to be a man of a fine imagination. “Perhaps,” says he, “many of his readers will be sorry to be undeceived about his Theory; for, as I believe never any book was fuller of mistakes and errors in philosophy, so none ever abounded | *vith more beautiful scenes and surprizing images of nature. But I write only to those who might expect to find a true philosophy in it: the*y who read it as an ingenious romance will still be pleased with their entertainment.”

The following year Dr. Millington, Sedleian professor of natural philosophy in Oxford, who had been appointed physician in ordinary to king William, substituted Keill as his deputy, to read lectures in the public schools. This office he discharged with great reputation; and the term of enjoying the Scotch exhibition at Baliol-college, without taking orders, now expiring, he accepted an invitation from Dr. Aldrich, dean of Christ-church, to reside there. In 1701 he published his celebrated treatise, the substance of several lectures on the new philosophy, entitled “Introductio ad veram physicam,” which is supposed to be the best and most useful of all his performances. In the preface he insinuates the little progress that Sir Isaac Newton’s “Principia” had made in the world and says, that “though the mechanical philosophy was then in repute, yet, in most of the writings upon this subject, scarce any thing was to be found but the name.” The first edition of this book contained only fourteen lectures; but to the second, in 1705, he added two more. About 50 years ago, when the Newtonian philosophy began to be established in France, this piece was in great esteem there, being considered as the best introduction to the “Principia;” and a new edition in English was printed at London in 1736, at the instance of M. Maupertuis, who was then in England, and subjoined to it a new hypothesis of his own, concerning the ring of the planet Saturn.

In Feb. 1701 he was admitted a fellow of the royal society; and, in 1708, published, in the “Philosophical Transactions,” a paper “Of the Laws of Attraction, and its Physical Principles.” At the same time, being offended at a passage in the “Acta Eruditorum” at Leipsic, in which Sir Jsaac Newton’s claim to the first invention of the method of fluxions was called in question, he communicated to the royal society another paper, in which he asserted the justice of that claim. In 1709 he was appointed treasurer to the Palatines, and in that station attended them in their passage to New England; and, soon after his return in 1710, was chosen Savilian professor of astronomy at Oxford. In 1711, being attacked by Leibnitz, he entered the lists against that mathematician, | in the dispute about the invention of fluxions. Leibnitz wrote a letter to Dr. Hans Sloane, then secretary to the royal society, dated March 4, 1711, in which he required Keill, in effect, to give him satisfaction for the injury he had done him in his paper relating to the passage in the “Acta Eruditorum” at Leipsic. He protested, that he was far from assuming to himself Sir Isaac Newton’s method of fluxions; and desired, therefore, that Keill might be obliged to retract his false assertion. Keill desired, on the other hand, that he might be permitted to justify what he had asserted which he performed to the approbation of Sir Isaac, and other members of the society and a copy of his defence was sent to Leibnitz, who, in a second letter, remonstrated still more loudly against Keill’s want of candour and sincerity; adding, that it was not fit for one of his age and experience to enter into a dispute with an upstart, who acted without any authority from Sir Isaac Newton and desiring that the royal society would enjoin him silence. Upon this, a special committee was appointed who, after examining the facts, concluded their report with “reckoning Mr. Newton the inventor of fluxions; and that Mr. Keill, in asserting the same, had been no ways injurious to Mr. Leibnitz.” In the mean time, Keill behaved himself with great firmness and spirit; which he also shewed afterwards in a Latin epistle, written in 172O, to Bernoulli, mathematical professor at Basil, on account of the same usage shewn to Sir Isaac Newton; in the title-page of which he put the arms of Scotland, viz. a thistle, with this motto, “Nemo me impune lacessit.” The particulars of the contest are recorded in Collins’s “Commercium Epistolicum.”

About 1711, several objections were urged against Sir Isaac Newton’s philosophy, in support of Des Cartes’s notions of a plenum; which occasioned Keill to draw up a paper, which was published in the “Philosophical Transactions,” “On the Rarity of Matter, and the Tenuity of its Compo sition,” in which he points out various phenomena, which cannot be explained upon the supposition of a plenum. But, while he was engaged in this controversy, queen Anne was pleased to appoint him her decipherer; a post for which he was, it seems, very fit. His sagacity was such, that, though a decipherer is always supposed to be moderately skilled in the language in which the paper given him to decipher is written; yet he is said once to have | deciphered a paper written in Swedish, without knowing a word of the language. In 1713, the university conferred on him the degree of M. D. at the public act; and, two years after, he published an edition of Commandinus’s “Euclid,” with additions of his own, of two tracts on Trigonometry and the nature of Logarithms. In 1717 he was married to some lady, who recommended herself to him, it is said, purely by her personal accomplishments. The facetious Mr. Alsop wrote some lines on this occasion (Gent. Mag. vol. XXXVIII. 238), which intimate that Keill had been a man of gallantry in his youth; and this appears, indeed, to be confirmed by the writer of his life in the Biographia Britannica. In 1718 he published his “Introductio ad veram Astronomiam:” which treatise was afterwards, at the request of the duchess of Chandos, translated by himself into English; and, with several emendations, published in 1721, under the title of “An Introduction to the true Astronomy, or, Astronomical Lectures read in the Astronomical Schools of the University of Oxford.” This was his last gift to the public; for he was seized this summer with a violent fever, which put an end to his life Sept. 1, 1721, when he was not quite fifty years old. ¹