beginning of 1693 Newton’s health was considerably impaired, and he laboured in the summer under some epidemic disorder. It is not likely that the precise character or amount of his indisposition will ever be discovered; but it seems, though the opinion has been much controverted, that for a short time it affected his understanding, and that in September, 1693, he was not in the full possession of his mental faculties. The disease was soon removed, and there is no reason to suppose that it ever recurred. But the course of his life was changed; and from this time forward he devoted himself chiefly to the completion of his former works, and abstained from any new career of continued research.
His time indeed was less at his own disposal than it had been. In 1696, Mr. Montague, the Chancellor of the Exchequer, an early friend of Newton, appointed him to the Wardenship of the Mint, and in 1699 he was raised to the office of Master. He removed to London, and was much occupied, especially during the new coinage in 1696 and 1697, with the duties of his office. Still he found time to superintend the editions of his earlier works, which successively appeared with very material additions and improvements. The great work on Optics appeared for the first time in a complete form in 1704, after the death of Hooke had freed Newton from the fear of new controversies. It was accompanied by some of his earlier mathematical treatises; and contained also, in addition to the principal subject of the work, suggestions on a variety of subjects of the highest philosophical interest, embodied in the shape of queries. Among these is to be found the first suggestion of the polarity of light; and we may mention at the same time, although they occur in a different part of the work, the remarkable conjectures, since verified, of the combustible nature of the diamond, and the existence of an inflammable principle in water. The second edition of the Principia appeared under the care of Cotes in 1713, after having been the subject of correspondence between Newton and his editor for nearly four years. Dr. Pemberton published a third edition in 1725, and he frequently communicated about the work with Newton who was then eighty-two years old.
These were the chief scientific employments of Newton’s latter life: and it is not necessary to particularize all its minor details. In 1712 he made some improvements in his Arithmetica Universalis, a work containing his algebraical discoveries, of which Whiston had surreptitiously published an edition in 1707. It is also worthy of remark that at the beginning of the year 1697, John Bernouilli addressed two problems as a challenge to the mathematicians of Europe, and that Leibnitz in 1716 made a similar appeal to the English analysts; and that Newton in each case undertook and succeeded in the investigation.
This enumeration of Newton’s philosophical employments has far outrun the order of time. After his return to London, compliments and honours flowed in rapidly upon him. In 1699 he was elected one of the first foreign associates of the Académie des Sciences at Paris; and in 1701 he was a second time returned to Parliament by the University of Cambridge. He did not, however, long retain his seat. At the election in 1705 he was at the bottom of the poll, and he does not appear again to have been a candidate. In 1703 he was chosen President of the Royal Society, and held that office till his death. In 1705 he was knighted by Queen Anne upon her visit to Cambridge.
Newton’s life in London was one of much dignity and comfort. He was courted by the distinguished of all ranks, and particularly by the Princess of Wales, who derived much pleasure from her intercourse both with him and Leibnitz. His domestic establishment was liberal, and was superintended during great part of his time by his niece, Mrs. Barton, a woman of much beauty and talent, who married Mr. Conduitt, his assistant and successor at the Mint. Newton’s liberality was almost boundless, yet he died rich.
The only material drawback to Newton’s enjoyment during this portion of his life, seems to have arisen from controversies as to the history and originality of his discoveries; a molestation to which his slowness to publish them very naturally exposed him. There was a long and angry dispute with Leibnitz about the priority of fluxions or the differential calculus; and, after the fashion of most disputes, it diverged widely from the original ground, and it became necessary for Newton to vindicate the religious and metaphysical tendencies of his greatest works. His success was complete on all points. Leibnitz does not appear to have been acquainted with the method of fluxions at the time of his own discovery, but there is now no doubt of Newton’s having preceded him by some years; and the attacks made on the tendency of Newton’s discoveries have long been remembered only as disgracing their author. But such discussions had always been distasteful to Newton, and this controversy, which was conducted with great rancour by his opponents and some of his supporters, embittered his later years.
The same fate awaited him in another instance. His system of Chronology had been long conceived, but he had not communicated it to any one until he explained it to the Princess of Wales. At her desire, he afterwards, in 1718, drew up a short abstract of it for her use, and sent it to her on condition that no one else should see it. She afterwards requested that the Abbé Conti might have a copy of it, and Newton complied, but still on the terms that it should not be farther divulged. Conti, however, showed the manuscript at Paris to Freret, who, without the author’s permission, translated and published it with observations in opposition to its doctrines. Newton drew up a reply which was printed in the Philosophical Transactions for 1725, and this was the signal for a new attack by Souciet. Newton was then roused to his last great exertion, that of fully digesting his system; which as yet existed only in confused papers, and preparing it for the press. He did not live to complete his task, but the work was left in a state of great forwardness, and was published in 1728 by Mr. Conduitt. Its value is well known. As a refutation of the systems of chronology then received, it is almost demonstrative; and the affirmative conclusions, if not always minutely correct, or even generally satisfactory, are yet among the most valuable contributions which science has made to history.
With the exception of the attack of 1693, Newton’s health had usually been very good. But he suffered much from stone during the last few years of his life. His mental faculties remained in general unaffected, but his memory was much impaired. From the year 1725 he lived at Kensington, but was still fond of going occasionally to London, and visited it on February 28th, 1727, to preside at a meeting of the Royal Society. The fatigue appears to have been too great: for the disease attacked him violently on the 4th of March, and he lingered till the 20th, when he died. His sufferings were severe, but his temper was never soured, nor the benevolence of his nature obscured. Indeed his moral was not less admirable than his intellectual character, and it was guided and supported by that religion, which he had studied not from speculative curiosity, but with the serious application of a mind habitually occupied with its duties, and earnestly desirous of its advancement.
Newton died without a will, and his property descended to Mrs. Conduitt and his other relations in the same degree. He was buried with great pomp in Westminster Abbey, where there is a monument to his memory, erected by his relations. His Chronology appeared, as has been already mentioned, almost immediately after his death; and the Lectiones Opticæ, the substance of his lectures at Cambridge in the years 1669, 1670, and 1671, were published from his manuscripts in 1729. In 1733, Mr. Benjamin Smith, one of the descendants of his mother’s second marriage, published the Observations on the Prophecies. These, in addition to the works already mentioned, are Newton’s principal writings; there are, however, several smaller tracts, some of which appeared during his lifetime, and some after his death, which it is not necessary here to specify. They would have conferred much honour on most philosophers;—they are hardly remembered in reckoning up Newton’s titles to fame.
Roubiliac’s Statue from the Chapel of Trinity College.
Many portraits of Newton are in existence. The Royal Society possesses two; and Lord Egremont is the owner of one, which is engraved as the frontispiece to Dr. Brewster’s Life of Newton. Trinity College, Cambridge, abounds in memorials of its greatest ornament. Almost every room dedicated to public purposes possesses a picture of him, and the chapel is adorned by Roubiliac’s noble statue. The library also has a bust by the same artist, of perhaps even superior excellence. As works of art these are far superior to any of the
