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## CHAPTER XVII.

NEWTON'S HEALTH IMPAIRED — THE BOYLE LECTURES BY BENTLEY, WHO REQUESTS NEWTON'S ASSISTANCE — NEWTON'S FIRST LETTER TO BENTLEY ON THE FORMATION OF THE SUN AND PLANETS — HIS SECOND LETTER — ROTATION OF THE PLANETS THE RESULT OF DIVINE POWER — HIS THIRD LETTER — HYPOTHESIS OF MATTER EVENLY DIFFUSED — LETTER OF BENTLEY TO NEWTON — REPLY TO IT BY NEWTON IN A FOURTH LETTER — OPINION OF PLATO EXAMINED — SUPPOSED MENTAL ILLNESS OF NEWTON ASCRIBED TO THE BURNING OF HIS MSS. — REFERRED TO IN THE LETTERS OF HUYGENS AND LEIBNITZ — MADE PUBLIC BY M. BIOT — MENTIONED IN THE DIARY OF MR. DE LA PRYME — THE STORY REFERRED TO DISPROVED— NEWTON'S PAPERS BURNT BEFORE 1684 — NEWTON'S LETTER TO MR. PEPYS — LETTER OF MR. PEPYS TO MR. MILLINGTON — MR. MILLINGTON'S REPLY — MR. PEPYS' SECOND LETTER TO MR. MILLINGTON — NEWTON SOLVES A PROBLEM IN CHANCES — HIS LETTER TO LOCKE — REPLY OF LOCKE — NEWTON'S ANSWER, EXPLAINING THE CAUSE OF HIS ILLNESS — HIS CRITICAL LETTER TO DR. MILL — HIS MIND NEVER IN A STATE OF DERANGEMENT, BUT FITTED FOR THE HIGHEST INTELLECTUAL EFFORTS.

In the autumn of 1692, wlien Newton had finished his letters on fluxions, he did not enjoy that degree of health with which he had so long been favoured. The loss of appetite and want of sleep, of which he now complained, and which continued for nearly a twelvemonth, could not fail to diminish that mental vigour, and that "consistency of mind," as he himself calls it, which he had hitherto displayed. How far this ailment may have arisen from the disappointment which he experienced in the application of his friends for a permanent situation for him, we have not the means of ascertaining, but it is impossible <124> to read his letters to Locke, and other letters from his friends, without perceiving that a painful impression had been left upon his mind, as well as upon theirs. This state of his health, however, did not unfit him for studies that required perhaps more profound thought than his letters on fluxions and fluents, for it was at the close of 1692, and during the first two months of 1693, that he composed his four celebrated letters to Dr. Bentley.[1]

Upon the death of the celebrated Robert Boyle, who died on the 30th December 1691, it was found that, in a codicil to his will, he had left £50 per annum to establish a lectureship, in which eight discourses were to be preached annually in one of the churches of the metropolis, in illustration of the evidences of Christianity, and in opposition to the principles of infidelity. Dr. Bentley, then chaplain to the Bishop of Worcester, and a very young man, was appointed to preach the first course of sermons, and the manner in which he discharged this important duty gave the highest satisfaction not only to the trustees of the lectureship, but to the public in general. In the first six lectures Bentley exposed the folly of atheism even in reference to the present life, and derived powerful arguments for the existence of a Deity from the faculties of the soul, and the structure and functions of the human frame. In order to complete his plan, he proposed to devote his seventh and eighth lectures to the demonstration of a Divine Providence from the physical constitution of the universe, as established in the Principia. <125> To qualify himself for this task, he received from Sir Isaac Newton directions respecting a list of books necessary to be perused previous to the study of that work;[2] and having made himself master of the system which it contained, he applied it with irresistible force of argument to establish the existence of an overruling mind. Previous to the publication of these lectures, Bentley encountered a difficulty which he was not able to solve, and he transmitted to Sir Isaac, during 1692, a series of queries on the subject. This difficulty occurred in an argument urged by Lucretius, to prove the eternity of the world from a hypothesis of deriving the frame of it, by mechanical principles, from matter endowed with an innate power of gravity, and evenly scattered throughout the heavens. Sir Isaac willingly entered upon the consideration of the subject, and transmitted his sentiments to Dr. Bentley in the four letters which we have mentioned.

In the First[3] of these letters Sir Isaac informs him, that when he wrote his treatise about our system, viz., the Third Book of the Principia, "he had an eye upon such principles as might work, with considering men, for the belief of a Deity," and he expresses his happiness that it has been found useful for that purpose. "But if I have done," he adds, "the public any service this way, it is due to nothing but industry and patient thought." In answering the first query of Dr. Bentley, the exact import of which we do not know, he states, that, if matter were evenly diffused through a finite space, and endowed with innate gravity, it would fall down into the middle of the <126> space, and form one great spherical mass; but if it were diffused through an infinite space, some of it would collect into one mass, and some into another, so as to form an infinite number of great masses. In this manner the sun and stars might be formed if the matter were of a lucid nature. But he thinks it inexplicable by natural causes, and to be ascribed to the counsel and contrivance of a voluntary agent, that the matter should divide itself into two sorts, part of it composing a shining body like the sun, and part an opaque body like the planets. Had a natural and blind cause, without contrivance and design, placed the earth in the centre of the moon's orbit, and Jupiter in the centre of his system of satellites, and the sun in the centre of the planetary system, the sun would have been a body like Jupiter and the earth, that is, without light and heat; and consequently, he knows no reason why there is only one body qualified to give light and heat to all the rest, but because the Author of the system thought it convenient, and because one was sufficient to warm and enlighten all the rest.

To the second query of Dr. Bentley, he replies that the motions which the planets now have could not spring from any natural cause alone, but were impressed by an intelligent agent. "To make such a system with all its motions, required a cause which understood, and compared together the quantities of matter in the several bodies of the sun and planets, and the gravitating powers resulting from thence; the several distances of the primary planets from the sun, and of the secondary ones from Saturn, Jupiter, and the earth, and the velocities with which those planets could revolve about those quantities of matter in the central bodies; and to compare and adjust all these things together in so great a variety of bodies, argues that <127> cause to be not blind and fortuitous, but very well skilled in mechanics and geometry." In his answer to the third query, he expresses the opinion that the interior parts of all the planets are "as much heated, concocted, and coagulated by interior fermentation as our earth is," and that the exterior planets, Jupiter and Saturn, have a smaller density than the rest, not because they are at a greater distance from the sun, but because if their density had been greater they would "have caused a considerable disturbance in the whole system."

In answering the fourth query, he says that, in the system of vortices, even if "the sun could, by his rays, carry about the planets, yet he does not see how he could thereby effect their diurnal motion."

In the Second letter,[4] he admits that the spherical mass formed by the aggregation of particles would affect the figure of the space in which the matter was diffused, provided the matter descends directly downwards to that body, and the body has no diurnal rotation; but he states, that by earthquakes loosening the parts of this solid, the protuberances might sink a little by their weight, and the mass by degrees approach a spherical figure. He then proceeds to correct an error of Dr. Bentley's in supposing that all infinites are equal, and refers him for information to Dr. Wallis's Arithmetic of Infinites. He admits that gravity might put the planets in motion, but he maintains that, without the Divine power, it could never give them such a circulating motion as they have about the sun, because a proper quantity of a transverse motion is necessary for this purpose; and he concludes that he is compelled to ascribe the frame of this system to an intelligent agent.

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In the Third letter,[5] he states, that the hypothesis that matter is at first evenly diffused through the universe, is in his opinion inconsistent with the hypothesis of innate gravity without a supernatural power to reconcile them, and therefore it infers a Deity. "For if there be innate gravity, it is impossible now for the matter of the earth and all the planets and stars to fly up from them, and become evenly spread throughout all the heavens without a supernatural power; and certainly that which can never be hereafter without a supernatural power, could never be heretofore without the same power."

Having learned from his bookseller that the publication of his sermons might be delayed, Bentley, upon the receipt of the preceding letter, wrote to Newton a long letter,[6] containing "an abstract, and thread of his first unpublished sermon," and requested him, in order to make "his mind at ease," to "acquaint him with what he found in it not conformable to truth and his hypothesis." In citing, in his abstract, Newton's opinions on gravity, he gives the full passage in his sermon, and adds in a parenthesis, "I have written these words at large that you may see if I am tender enough how I engage your name in this matter."

To this letter Newton replied in a few days by a fourth letter[7] of great interest, and touching on all the points to which his correspondent, had called his attention.

The Fourth letter contains opinions confirming or correcting several positions which Dr. Bentley had laid down, and closes with a curious examination of the opinion of Plato, that the motion of the planets is such as <129> if they had been all created by God in some region very remote from our system, and let fall from thence towards the sun, their falling motion being turned aside into a transverse one whenever they arrived at their several orbits. Sir Isaac shows that there is no common place such as that conjectured by Plato, provided the gravitating power of the sun remains constant; but that Plato's affirmation is true if we suppose the gravitating power of the sun to be doubled at that moment of time when they all arrive at their several orbits. "If we suppose," says he, "the gravity of all the planets towards the sun to be of such a quantity as it really is, and that the motions of the planets are turned upwards, every planet will ascend to twice its height from the sun. Saturn will ascend till he be twice as high from the sun as he is at present, and no higher; Jupiter will ascend as high again as at present, that is, a little above the orb of Saturn; Mercury will ascend to twice his present height, that is, to the orb of Venus; and so of the rest; and then, by falling down again from the places to which they ascended, they will arrive again at their several orbs with the same velocities they had at first, and with which they now revolve.

"But if so soon as their motions by which they revolve are turned upwards, the gravitating power of the sun, by which their ascent is perpetually retarded, be diminished by one-half, they will now ascend perpetually, and all of them, at all equal distances from the sun, will be equally swift. Mercury, when he arrives at the orb of Venus, will be as swift as Venus; and he and Venus, when they arrive at the orb of the earth, will be as swift as the earth; and so of the rest. If they begin all of them to ascend at once, and ascend in the same line, they will constantly, in ascending, become nearer and nearer to <130> gether, and their motions will constantly approach to an equality, and become at length slower than any motion assignable. Suppose, therefore, that they ascended till they were almost contiguous, and their motions inconsiderably little, and that all their motions were at the same moment of time turned back again, or which comes almost to the same thing, that they were only deprived of their motions, and let fall at that time, they would all at once arrive at their several orbs, each with the velocity it had at first; and if their motions were then turned sideways, and at the same time the gravitating power of the sun doubled, that it might be strong enough to retain them in their orbs, they would revolve in them as before their ascent. But if the gravitating power of the sun was not doubled, they would go away from their orbs into the highest heavens in parabolical lines."[8]

These letters, of which we have endeavoured to give a brief summary, will well repay the most attentive perusal by the philosopher as well as the divine. They are written with much perspicuity of language, and great power of thought, and contain results which incontestably prove that their author was fully master of his noblest faculties, and comprehended the profoundest parts of his own writings.[9] In the present day they possess a peculiar in <131> terest. They show that the Nebular hypothesis, the dull and dangerous heresy of the age, is incompatible with the established laws of the material universe, and that an omnipotent arm was required to give the planets their position and motions in space, and a presiding intelligence to assign to them the different functions they had to perform.[10]

The illness of Newton, which increased till the autumn of 1693, was singularly misrepresented by foreign contemporary authors, to whom an erroneous account of it had been communicated. During the century and a half which has elapsed since that event, it has never been mentioned by any of his biographers; and it was not till 1822 that it was brought before the public as a remarkable event in the life of Newton. The celebrated Dutch philosopher, Van Swinden, made the following communication to M. Biot, who published it,[11] with comments, that gave great offence to the friends of Newton: —

"There is among the manuscripts of the celebrated Huygens," says Van Swinden, "a small journal in folio, in which he used to note down different occurrences. It is note ζ, No. 8, in the Catalogue of the Library of Leyden, p. 112. The following extract is written by Huygens himself, with whose handwriting I am well acquainted, having had occasion to peruse several of his manuscript and autograph letters: —

"'On the 29th May, 1694, M. Colin,[12] a Scotchman, in <132> formed me, that eighteen months ago the illustrious geometer, Isaac Newton, had become insane, either in consequence of his too intense application to his studies, or from excessive grief at having lost, by fire, his chemical laboratory and several manuscripts. When he came to the Archbishop of Cambridge, he made some observations which indicated an alienation of mind. He was immediately taken care of by his friends, who confined him to his house, and applied remedies, by means of which he had now so far recovered his health that he began to understand the Principia.'"[13] Huygens mentioned this circumstance in a letter to Leib <133> nitz, dated 8th June 1694,[14] in the following terms: — "I do not know if you are acquainted with the accident which has happened to the good Mr. Newton, namely, that he has had an attack of phrenitis, which lasted eighteen months, and of which they say that his friends have cured him by means of remedies, and keeping him shut up." To which Leibnitz replied in a letter, dated the 22d June: — "I am very glad that I received information of the cure of Mr. Newton at the same time that I first heard of his illness, which doubtless must have been very alarming. 'It is to men like you and him, sir, that I wish a long life and much health, more than others, whose loss, comparatively speaking, would not be so great.'"[15]

The first publication of the preceding statement produced a strong sensation among the friends and admirers of Newton. They could not easily believe in the prostration of that intellectual strength which had unbarred the strongholds of the universe. The unbroken equanimity of Newton's mind, the purity of his moral character, his temperate and abstemious life, his ardent and unaffected piety, and the weakness of his imaginative powers, all indicated a mind which was not likely to be overset by any affliction to which it could be exposed. The loss of a few experimental records could never have disturbed the equilibrium of a mind like his. If they were the records of discoveries, the discoveries, themselves indestructible, would have been afterwards given to the world. If they were merely the details of experimental results, a little time could have easily reproduced them. Had these records contained the first-fruits of youthful genius — of <134> obscure talent, on which fame had not yet shed its rays, we might have supposed that the first blight of early ambition would have unsettled the stability of a mind unannealed by the world. But Newton was satiated with fame. His mightiest discoveries were completed, and diffused over all Europe, and he must have felt himself placed on the loftiest pinnacle of earthly ambition. The incredulity which such views could not fail to encourage, was increased by the novelty of the information. No English biographer had ever alluded to such an event. History and tradition were equally silent, and it was not easy to believe that the Lucasian Professor of Mathematics at Cambridge, recently a Member of the English Parliament, and the first philosopher and mathematician in Europe, could have lost his reason without the dreadful fact being known to his countrymen.

But if the friends of Newton were surprised by the nature of the intelligence, they were distressed at the view which was taken of it by foreign philosophers. "The fact," says M. Biot, "of the derangement of his intellect, whatever may have been the cause of it, will explain why, after the publication of the Principia in 1687, Newton, though only forty-five years old, never more published a new work on any branch of science, but contented himself with giving to the world those which he had composed long before that epoch, confining himself to the completion of those parts which might require development. We may also remark, that even these developments appear always to be derived from experiments and observations formerly made, such as the additions to the second edition of the Principia, published in 1713, the experiments on thick plates, those on diffraction, and the chemical queries placed at the end of the Optics in 1704; for in giving <135> an account of these experiments Newton distinctly says, that they were taken from ancient manuscripts which he had formerly composed; and he adds, that though he felt the necessity of extending them, or rendering them more perfect, he was not able to resolve to do this, these matters being no longer in his way. Thus it appears that though he had recovered his health sufficiently to understand all his researches, and even in some cases to make additions to them, and useful alterations, as appears from the second edition of the Principia, for which he kept up a very active mathematical correspondence with Mr. Cotes, yet he did not wish to undertake new labours in those departments of science where he had done so much, and where he so distinctly saw what remained to be done." Under the influence of the same opinion, M. Biot finds it "extremely probable that his dissertation on the scale of heat was written before the fire in his laboratory;" and he describes Newton's conduct about the longitude bill as exhibiting an inexplicable timidity of mind, and as "so puerile for so solemn an occasion, that it might lead to the strangest conclusions, particularly if we refer it to the fatal accident which befell him in 1695."

The illness of Newton was viewed in a light still more painful to his friends. It was maintained that he never recovered the vigour of his intellect, and that his theological inquiries did not commence till after that afflicting epoch of his life. In reply to this groundless assertion, it may be sufficient to state, in the words of his friend John Craig,[16] that his theological writings were composed "while his understanding was in its greatest perfection, lest the infidels might pretend that his apply <136> ing himself to the study of religion was the effect of dotage."

Such having been the consequences of the disclosure of Newton's illness by the manuscript of Huygens, I felt it to be a sacred duty to the memory of that great man, and to the feelings of his countrymen, to inquire into the nature and history of that indisposition which seems to have been so much misrepresented and misapplied. From the ignorance of so extraordinary an event which has prevailed for such a long period in England, it might have been urged with some plausibility, that Huygens had mistaken the real import of the information that was conveyed to him; or that the person from whom he received it had propagated an idle and a groundless rumour. But we are fortunately not confined to this very reasonable mode of defence. There exists at Cambridge a manuscript journal written by Mr. Abraham de la Pryme, who was a student in the University while Newton was a Fellow of Trinity. This manuscript is entitled "Ephemeris Vitæ?, or Diary of my own Life, containing an account likewise of the most observable and remarkable things that I have taken notice of from my youth up hitherto." Mr. A. de la Pryme was born in 1671, and begins the Diary in 1685. This manuscript is in the possession of his collateral descendant, George Pryme, Esq., Professor of Political Economy at Cambridge, to whom I have been indebted for the following extract, which is given verbatim, and occurs during the period when Mr. de la Pryme was a student in St. John's College, Cambridge: —

"1692, February 3d. — What I heard to-day I must relate. There is one Mr. Newton (whom I have very oft seen,) Fellow of Trinity College, that is mighty famous for his learning, being a most excellent mathematician, <137> philosopher, divine, &c. He has been Fellow of the Royal Society these many years; and amongst other very learned books and tracts he's written one upon the mathematical principles of philosophy, which has got him a mighty name, he having received, especially from Scotland, abundance of congratulatory letters for the same; but of all the books that he ever wTote, there was one of colours and light, established upon thousands of experiments, which he had been twenty years of making, and which had cost him many hundred of pounds. This book, which he valued so much, and which was so much talked of, had the ill luck to perish, and be utterly lost, just when the learned author was almost at putting a conclusion at the same, after this manner: — In a winter's morning, leaving it amongst his other papers on his study table whilst he went to chapel, the candle, which he had unfortunately left burning there too, catched hold by some means of other papers, and they fired the aforesaid book, and utterly consumed it and several other valuable writings; and, which is most wonderful, did no further mischief. But when Mr. Newton came from chapel, and had seen what was done, every one thought he would have run mad, he was so troubled thereat that he was not himself for a month after. A long account of this his system of light and colours you may find in the Transactions of the Royal Society, which he had sent up to them long before this sad mischance happened unto him."

The story of the burning of Newton's laboratory and papers, as stated by Mr. de la Pryme, has been greatly exaggerated and misrepresented, and there can be no doubt that it was entirely unconnected with Newton's illness. Mr. Edleston[17] has placed it beyond a doubt <138> that the burning of the manuscripts took place between 1677 and 1683, and I have found ample confirmation of the fact from other sources of information. Dr. H. Newton, as we have seen, tells us that he had heard a report that Newton's Optics had been burnt before he wrote his Principia, and we know that no such accident took place during the five years that Dr. Newton lived with him at Cambridge. The following memorandum of Mr. Conduitt's, written after conversing on the subject with Newton himself, appears to place the event at an early period: — "When he was in the warmest pursuit of his discoveries, he going out, left a candle upon his table amongst his papers, he went down into the bowling-green, and meeting somebody who diverted him from returning as, he intended, the candle set fire to his papers (and he could never recover them.^[18]). Upon my asking him whether they related to his Optics or the Method of Fluxions, he said he believed there was some relating to both, and that he was obliged to work them all over again." The version of the burnt papers in which "Diamond" is made the perpetrator, and in which the scene of the story is laid in London, and in Newton's later years, we may consign to a note, with the remark of Dr. Humphrey Newton, that Sir Isaac never had any communion with dogs or cats.[19]

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By means of this extract from Mr. de la Pryme' s Diary, we are enabled to fix the latest date of the accident by which Newton lost his papers. It must have been previous to the 3d January 1692, a month before the date of the extract; but if we fix it by the dates in Huygens's manuscript, we should place it about the 29th November 1692, eighteen months previous to the conversation between Colin and Huygens. The manner in which Mr. Pryme refers to Newton's state of mind is that which is used every day when we speak of the loss of tranquillity which arises from the ordinary afflictions of life; and the meaning of the passage amounts to nothing more than that Newton was very much troubled by the destruction of his papers, and did not recover his serenity, and return to his usual occupations, for a month. The very phrase, that every person thought he would have run mad, is in itself a proof that no such effect was produced; and, whatever degree of indisposition may be implied in the phrase, "he was not himself for a month after," we are entitled to infer that one month was the period of its duration, and that previous to the 3d February 1692, the date of Mr. Pryme's memorandum, "Newton was himself again."[20]

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These facts and dates cannot be reconciled with those in Huygens' manuscript.[21] It appears from that document, that, so late as May 1694, Newton had only so far recovered his health as to begin to again understand the Principia. His supposed malady, therefore, was in force from the 3d of January 1692, till the month of May 1694, — a period of more than two years. Now, it is a most important circumstance, which M. Biot ought to have known, that in the very middle of this period, Newton wrote his four celebrated letters to Dr. Bentley on the Existence of a Deity, — letters which evince a power of thought and a serenity of mind absolutely incompatible even with the slightest obscuration of his faculties. No man can peruse these letters without the conviction that their author then possessed the full vigour of his reason, and was capable of understanding the most profound parts of his writings. The first of these letters was written on the 10th December 1692, the second on the 17th January 1693, the third on the 11th February, and the fourth on the 25th February 1693. His mind was, therefore, strong and vigorous on these four occasions; and as the letters were written at the express request of Dr. Bentley, to assist him in preparing his lectures for publication, we must consider such a request as showing his opinion of the strength and freshness of his friend's mental powers.

In August and September 1692, as we have already seen, Newton transmitted to Dr. Wallis the first proposition of his book on quadratures, with examples of it in <141> first, second, and third fluxions.[22] These examples were written at the request of his friend: and the author of the review of the Commercium Epistolicum, in which this fact is quoted, draws the conclusion, that he had not at that time forgotten his method of second fluxions. It appears, also, from the second book of the Optics,[23] that in the month of June 1692, he had been occupied with the subject of haloes, and had made accurate observations both on the colours and the diameters of the rings in a halo which he had then seen around the sun. We find also from his manuscripts, that he was deeply engaged in chemical experiments in the months of December 1692 and January 1693; and on the 26th October 1693, he wrote a letter to Leibnitz, giving him, at his request, an account of his method of reducing quadratures to the rectification of curves, and, three months afterwards, another letter to Dr. Mill at Oxford.[24] In addition to these facts, it may be useful to mention that Facio Duillier visited Newton at Cambridge in the middle of November 1692;[25] and it is evident from Facio's letter to him, dated November 17, and from a letter of Newton's to Facio of the 14th March 1693,[26] that he was in comparatively good health.

But though these facts stand in direct contradiction to the statement recorded by Huygens, the reader will be naturally anxious to know the real nature and extent of the indisposition to which it probably refers. The following letters, written by Newton himself to Mr. Pepys, Secretary to the Admiralty, and Mr. Millington of Mag <142> dalene College, Cambridge, for which I have been indebted to the kindness of Lord Braybrooke, will throw much light upon the subject.

Newton, as will be presently seen, had fallen into a bad state of health in the autumn of 1692, in consequence of which both his sleep and his appetite were greatly affected. About the middle of September 1693, he had been kept awake for five nights by this nervous disorder, and in this condition he wrote the following letter to Mr. Pepys: —

"September 13, 1693.

"SIR, — Some time after Mr. Millington had delivered your message, he pressed me to see you the next time I went to London. I was averse; but upon his pressing consented, before I considered what I did, for I am extremely troubled at the embroilment I am in, and have neither ate nor slept well this twelvemonth, nor have my former consistency of mind. I never designed to get anything by your interest, nor by King James's favour, but am now sensible that I must withdraw from your acquaintance, and see neither you nor the rest of my friends any more, if I may but leave them quietly. I beg your pardon for saying I would see you again, and rest your most humble and most obedient servant,

"Is. NEWTON."

From this letter we learn, on his own authority, that his complaint had lasted for a twelvemonth, and that during that period he neither ate nor slept well, nor enjoyed his former consistency of mind. It is not easy to understand exactly what is meant by not enjoying his former consistency of mind; but whatever be its import, it is obvious that he must have been in a state of mind <143> which enabled him to compose the four letters to Bentley, and the other productions we have mentioned.

On the receipt of this letter, his friend, Mr. Pepys, seems to have written to Mr. Millington, to inquire after Mr. Newton's health; but the inquiry having been made in a vague manner, an answer equally vague was returned. Mr. Pepys, however, who seems to have been deeply anxious about Newton's health, addressed the following more explicit letter to Mr. Millington: —

"September 26, 1693.

"S. PEPYS."

"COLL. MAGD. CAMB., Sept. the 30, 1693.

"JOH. MILLINGTON."

Mr. Pepys was perfectly satisfied with this answer, as appears from the following letter: —

"October 3d, 1693.

"SIR, — You have delivered me from a fear that indeed gave me much trouble, and from my very heart I thank you for it, an evil to Mr. Newton being what every good man must feel for his own sake as well as his. God grant it may stopp here. And for the kind reflection hee has since made upon his letter to mee, I dare not take upon mee to judge what answer I should make him to it, or whether any or no; and therefore pray that you will bee pleased either to bestow on mee what directions you see fitt for my own guidance towards him in it, or to say to him in my name, but your own pleasure, whatever you think may be most welcome to him upon it, and most expressive of my regard and affectionate esteem of him, and concernment for him. I have a debt to acknowledge to you, (but was prevented in my last, by the thoughts I <146> was then overborne with in this matter), from the great satisfaction you was pleased to give me by your pupil (on whose behalf I have lasting thanks also to pay you) to my enquiries about Mr. Pyets, beseeching you to make the same scruplelesse use of me in whatever relation you can think me capable of rendering you any service, for I would do it with great pleasure, remaining, dear Sir, your most humble and most faithful servant,

"S. PEPYS."

It does not appear from the Memoirs of Mr. Pepys that he returned any answer to the letter of Mr. Newton, which occasioned this correspondence; but we find, that in less than two months after the date of the preceding letter, an opportunity occurred of introducing to him a Mr. Smith, who took a journey to Cambridge to obtain his opinion on a problem in the doctrine of chances. This problem related to "the project of Mr. Neale, the groom-porter's lottery," which Pepys says Newton "cannot but have heard of," as it "has almost extinguished, for some time, at all places of public conversation, especially among men of numbers, every other talk but what relates to the doctrine of determining between the true proportion of the hazards incident to this or that given chance or lot." "Mr. Smith," he says, "was concerned (more than in jest) to compass a solution, that may be relied on beyond what his modesty would suffer him to think his own alone, or any less than Mr. Newton's to be."

Mr. Pepys's introductory letter was dated November 22, 1693, and Newton returned an answer on the 26th, in which he explains the ambiguity of the question as proposed to him. He takes the question, however, to be, —

<147>

"What is the expectation of A to throw every time one six at least with six dice?

"What is the expectation of B to throw every time two sixes at least with twelve dice?

"What is the expectation of C to throw every time three sixes at least with eighteen dice?

"And whether has not B and C as great an expectation to hit every time what they throw for?

"If the question be thus stated, it appears by an easy computation that the expectation of A is greater than that of B and C, — that is, the task of A is the easiest, — and the reason is because A has all the chances in sixes on his dice for his expectation; but B and c have not all the chances upon theirs, for, when B throws a single six, or C but one or two sixes, they miss of their expectations."

In his reply, which I have not found among the Portsmouth papers, Pepys concurred in this statement of the question, and desired to have the "easy computation." Newton accordingly sent, on the 16th December, a table of eight progressions for making it. In returning thanks for the "easy computation," Pepys confessed that he did not understand how to make the full use of the table of progressions, and therefore put the question in a different form. This letter is dated December 21, 1693,[27] but Newton's answer to it has not been found. In perusing this correspondence, the mathematical reader will have no doubt of the consistency of Newton's mind, and of its fitness for the most profound research.

It is obvious from Newton's letter to Pepys, of the <148> 13th September, that the subject of his receiving some favour from the Government had been a matter of anxiety with himself, and of discussion among his friends. Mr. Millington was no doubt referring to this anxiety, when he represents Newton as an honour to the nation, and expresses his surprise "that such a person should lye so neglected hy those in power." We have already shown that the same subject was alluded to in his letters to Locke in 1692. In all these letters Newton no doubt referred to some appointment in London which he was solicitous to obtain, and which Mr. Montague and his other friends may have failed in procuring. This opinion is confirmed by the letter of Mr. Montague, announcing to him his appointment to the wardenship of the Mint, in which he says that he is very glad he can at last give him good proof of his friendship.

In the same month in which Newton wrote to Mr. Pepys, we find him in correspondence with Mr. Locke. Displeased with his opinions respecting innate ideas, he had rashly stated that they struck at the root of all morality, and that he regarded the author of such doctrines as a Hobbist. Upon reconsidering these opinions, he addressed the following remarkable letter to Locke, written three days after his letter to Mr. Pepys, and consequently during the illness under which he then laboured: —

"SIR, — Being of opinion that you endeavoured to embroil me with women, and by other means, I was so much affected with it, as that when one told me you were sickly and would not live, I answered, 'twere better if you were dead. I desire you to forgive me this uncharitableness; for I am now satisfied that what you have done is just, and I beg your pardon for my having hard thoughts of <149> you for it, and for representing that you struck at the root of morality, in a principle you laid in your book of ideas, and designed to pursue in another book, and that I took you for a Hobbist.[28] I beg your pardon also for saying or thinking that there was a design to sell me an office, or to embroil me. — I am your most humble and unfortunate servant,

"Is. NEWTON.

"At the BULL, in Shoreditch, London, Sept. 16th, 1693."

To this letter, characterized by Mr. Dugald Stewart as ingenuous and infantine in its simplicity, Locke returned the following answer, which, as the same author justly remarks, "is written with the magnanimity of a philosopher, and with the good-humoured forbearance of a man of the world, breathing throughout so tender and unaffected a veneration for the good as well as great qualities of the excellent person to whom it is addressed, as demonstrates at once the conscious integrity of the writer, and the superiority of his mind to little passions."[29]

<150>

"OATES, Oct. 5th, 1693.

"My book is going to press for a second edition; and, though I can answer for the design with which I write it, yet, since you have so opportunely given me notice of what you have said of it, I should take it as a favour if you would point out to me the places that gave occasion <151> to that censure, that, by explaining myself better, I may avoid being mistaken by others, or unawares doing the least prejudice to truth or virtue. I am sure you are so much a friend to them both, that, were you none to me, I could expect this from you. But I cannot doubt but you would do a great deal more than this for my sake, who, after all, have all the concern of a friend for you, wish you extremely well, and am, without compliment, &c."[30]

"SIR, — The last winter, by sleeping too often by my fire, I got an ill habit of sleeping; and a distemper, which this summer has been epidemical, put me farther out of order, so that when I wrote to you, I had not slept an hour a night for a fortnight together, and for five days together not a wink. I remember I wrote to you, but what I said of your book I remember not. If you please to send me a transcript of that passage, I will give you an account of it if I can. — I am your most humble servant,

"IS. NEWTON.

"CAMBRIDGE, Oct. 15th, 1693."

Although the first of these letters evinces the existence of a nervous irritability which could not fail to arise from want of appetite and of rest, yet it is obvious that its author was in the full possession of his mental powers. The answer of Mr. Locke, indeed, is written upon the supposition that Newton was then qualified to point out the objectionable passages in his Book, that they might be corrected and better explained; and it deserves to be <152> remarked, that Mr. Dugald Stewart, who first published a portion of these letters, never imagined that Newton was labouring under any mental alienation.

In the autumn of 1693, when Newton was suffering most severely from want of appetite and sleep, we find him deeply engaged in biblical research — collating ancient manuscripts of the New Testament — criticising the manuscript works of Dr. John Mill of Edmund Hall, Oxford, and communicating to him the results of his labours. Only two letters of this correspondence have been found, the letter from Dr. Mill to Newton, requesting the return of his manuscript with his observations, and Newton's reply, showing how busily he had been occupied in the task assigned to him by his friend.[31]

Among the other evidences of Newton's consistency of mind, in May 1694, when he is said to have been only beginning to understand the Principia, we may mention the visit paid to him in the beginning of that month by David Gregory, who went to Cambridge for the purpose of "consulting the divine author of the Principia," on certain errors which appeared to have crept into that work.[32] On the 7th of the same month, probably when Gregory was at Cambridge, we find Newton denouncing the imposture of the haunted house, and scolding the Fellows <153> of Trinity and several of the scholars for their credulity.[33]

The erroneous opinion that Newton devoted his attention to theology only in the latter part of his life, may be considered as deriving some countenance from the fact, that the celebrated general scholium, at the end of the second edition of the Principia, published in 1713, did not appear in the first edition of that work. This argument has been ably controverted by the late Dr. J. C. Gregory of Edinburgh, on the authority of a manuscript of Newton, which seems to have been transmitted to his ancestor. Dr. David Gregory, between the years 1687 and 1698. This manuscript, which consists of twelve folio pages in Newton's handwriting, contains, in the form of additions, and scholia to some propositions in the third book of the Principia, an account of the opinions of the ancient philosophers on gravitation and motion, and on natural theology, with various quotations from their works. Attached to this manuscript are three very curious paragraphs. The two first appear to have been the original draught of the general scholium already referred to; and the third relates to the subject of an ethereal medium, respecting which he maintains an opinion diametrically opposite to that which he afterwards published at the end <154> of his Optics.[34] The first paragraph expresses nearly the same idea as some sentences in the scholium beginning "Deus summus est ens æternum, infinitum, absolute perfectum;"[35] and it is remarkable that the second paragraph is found only in the third edition of the Principia, which appeared in 1726, the year before Newton's death.

In reviewing the details which we have now given respecting the health and occupations of Newton from the beginning of 1692 to 1694, it is impossible to draw any other conclusion than that he possessed a sound mind, and was perfectly capable of carrying on his mathematical, his physical, and his theological inquiries. His friend and admirer, Mr. Pepys, residing within fifty miles of Cambridge, had never heard of his being attacked with any illness till he inferred it from the letter to himself written in September 1693. Mr. Millington, who lived in the same University, had been equally unacquainted with any such attack, and, after a personal interview with Newton, for the express purpose of ascertaining the state of his health, he assures Mr. Pepys, "that he is very well — that he fears he is under some small degree of mel <155> ancholy, but that there is no reason to suspect that it hath at all touched his understanding."

During this period of bodily indisposition, his mind, though in a state of nervous irritability, and disturbed by want of rest, was capable of putting forth its highest powers. At the request of Dr. Wallis he drew up examples of one of his propositions on the quadrature of curves in second fluxions. He composed, at the desire of Dr. Bentley, his profound and beautiful letters on the existence of the Deity. He was requested by Locke to reconsider his opinions on the subject of innate ideas. Dr. Mill engaged him in profound biblical researches, and we shall presently find him grappling with the difficulties of the lunar theory.

But with all these proofs of a vigorous mind, a diminution of his mental powers has been rashly inferred from the cessation of his great discoveries, and from his unwillingness to enter upon new investigations. The facts, however, here assumed, are as incorrect as the inference which is drawn from them. The ambition of fame is a youthful passion, which is softened, if not subdued, by age. Success diminishes its ardour, and early pre-eminence often extinguishes it. Before the middle period of his life Newton was invested with all the insignia of immortality; but endowed with a native humility of mind, and animated with those hopes which teach us to form a humble estimate of human greatness, he was satisfied with the laurels which he had won, and he sought only to perfect and complete his labours. Although his mind was principally bent on the improvement of the Principia, yet he occasionally diverged into new fields of scientific research — he created, as we shall see, his fine theory of astronomical refractions — he made great improvements on the lunar <156> theory — he solved difficult problems, which had been proposed to try his strength, — he wrote a profound letter to Leibnitz, — he made valuable additions to his "Opticks," — he continued his chemical experiments, — and he devoted much of his time to profound inquiries in chronology and theological literature.

The powers of his mind were therefore in full requisition; and, when we consider that he was called to the discharge of high official functions which forced him into public life, and compelled him to direct his genius into new channels, we can scarcely be surprised that he ceased to produce any very original works on abstract science. In the direction of the affairs of the Mint, and of the Royal Society, to which we shall now follow him, he found ample occupation for his time; while the leisure of his declining years was devoted to those exalted studies in which philosophy yields to the supremacy of faith, and hope administers to the aspirations of genius.

[1]

These letters, which were first printed by Richard Cumberland in 1756, and reviewed by Dr. Samuel Johnson in the Literary Magazine, vol. i, p. 89, have been reprinted in Dr. Horsley's Newtoni Opera, vol. iv. pp. 429-442; and in Nichol's Illustrations of the Literary History of the Eighteenth Century, vol. iv. pp. 50-60; but in both these works, the third and fourth letters are transposed, as their dates will show.

[2]

See vol. i., APPENDIX, p. 463.

[3]

Dated December 10, 1692. This letter is indorsed in Bentley's hand. — "Mr. Newton's answer to some queries sent by me after I had preached my two last sermons." — Monk's Life of Bentley, p. 34, note.

[4]

Dated Jan. 17, 1692-3.

[5]

Dated February 11, $169\frac{2}{3}$.

[6]

Dated February 19, $169\frac{2}{3}$, and printed in APPENDIX, No. X. This is the only letter of Bentley's on this subject which I have found aniong the Portsmouth Papers.

[7]

Dated February 25, $169\frac{2}{3}$.

[8]

"These things," says he, "follow from my Principia Math. lib. i. prop. 33-36."

[9]

The originals of these four letters "were given by Dr. Richard Bentley to Richard Cumberland, his nephew and executor, while a student at Trinity College, and were printed by him in a separate pamphlet in 1756. This publication was reviewed by Dr. Samuel Johnson in the Literary Magazine, vol. i. p. 89. See Johnson's Works, vol. ii. p. 328. In one or two cases Newton acknowledges that he had not before considered some of the conclusions from his own discoveries, and that some of the queries proposed by Bentley were new to him. Whence Dr. Johnson beautifully remarks "how even the mind of Newton gains ground gradually upon darkness." Dr. Monk, who notices this remark, justly observes, that as Bentley "availed himself of all the suggestions of his illustrious correspondent, his reasonings and conclusions appear with the highest of all human sanctions, and this department <131> of natural theology has perhaps never yet been so satisfactorily illustrated." — Life of Bentley, p. 34.

[10]

The views of Newton and Bentley, so distinctive of the College which they adorned, have been maintained and illustrated, with all the lights of modern science, by Professor Sedgwick in his noble Discourse on the Studies of the University.

[11]

Life of Newton, Biog. Universelle, tom. xxxi. p. 168.

[12]

It appears from a letter of Newton to Flamsteed, that he had proposed Sir Collins, of "this University," as one of the candidates for the vacancy in Christ Hospital, <132> occasioned by the resignation of Mr. Paget. He thought that he had mathematics enough, though young and inexperienced. From Flamsteed's unpublished reply to this letter, it would appear that Sir Collins was a son of John Collins, Newton's great and early friend. "Young Collins," he says, "may live to restore it, (the Hospital,) whom, therefore, you may do well to encourage to mind these studies. I doubt not he will be good in algebra; that was his father's talent. Astronomy will be most useful in the school. Our teachers in town understand little of it. Pray advise him to study the theory of the planets, and to make himself expert in calculation. Though I never saw him, yet for his father's sake, my good friend, and his own good report, he shall find me always ready to serve him." — April 27, 1695.

[13]

M. Uylenbroek, the editor of the correspondence between Huygens and Leibnitz, has given in an appendix the correct text of this passage, with his own observations upon it: —

"29 Maj. 1694. — Narravit mihi D. Colm (not Colin) Scotus virum celeberrimum ac summum geometram Is. Neutonum in phrenesin incidisse abhine anno et sex mensibus. An ex nimia studii assiduitate, an dolore infortunii, quod incendio laboratorium chymicum et scripta quædam amiserat? Cum ad Archiepiscopum Cantabrigiensem (Cantuariensem, as Mr. Edleston conjectures) venisset, ea locutum, quæ alienationem mentis indicarent. Deinde ab amicis cura ejus susceptam, domoque clauso remedia volenti nolenti adhibita, quibus jam sanitatem recuperavit, ut jam rursus librum suum Principiorum Philosophiæ Mathematicorum intelligere incipiat."

M. Uylenbroek adds his own opinion of the matter, as explained in my former Life of Newton: — "Hæc Colmi narratio, quam ex his ipsis MSS., Hugeniensis petitam, quondam evulgaverat Biotus, nuperrime Brewstero ansam præbuit inquirendi utrum revera Newtonus mentis morbo correptus fuerit necne. Testimonia, quæ attulit vir Cl. ea esse videntur e quibus probabiliter efficias Newtonum, currente anno 1692, solita mentis, corporisque valetudine non fuisse usum, at non ita eum morbo decubuisse ut eo impeditus fuerit quo minus studiis suis vacaret." — Christiani Hugenii Exercitationes Mathematicæ. Ed. P. J. Uylenbrock, fascic. ii. p. 171, Hag. An. 1833.

[14]

He made the same communication to the Marquis L'Hospital on the 16th June. Ch. Hug. Exercit. Math, fascic. i. p. 318.

[15] Ibid. fascic. i. p. 182.

[16]

Unpublished letter to Conduitt, April 7, 1727.

[17]

Correspondence, &c. pp. lxii. lxiii.

[18]

This observation, which is in another edition of the manuscript, is not inconsistent with the statement of Newton's having "worked them over again."

[19]

"Newton's temper was so mild and equal, that scarce any accident disturbed him. One instance in particular, which is authenticated by a person now living (1780,) brings this assertion to a proof. Sir Isaac being called out of his study to a contiguous room, a little dog called Diamond, the constant but incurious attendant of his master's researches, happened to be left among the papers, and by a fatality not to be retrieved, as it was in the latter part of Sir Isaac's days, threw down a lighted candle, which consumed the almost finished labours of some years. Sir Isaac returning too late but to behold the dreadful wreck, rebuked the author of it with an exclamation, (ad sidera palmas,) "O Diamond ! Diamond! thou little knowest the <139> mischief done!' without adding a single stripe." — Notes to Maude's Wensleydale, p. 102, fourth edit. 1816. M. Biot gives this piece of fiction as a true story, which happened in some year after the publication of the Principia, and he characterizes the accident as having deprived the sciences for ever of the fruit of so much of Newton's labours. Dr. Wallis received another edition of the story from his correspondent Sturm, a professor at Altorf. "Sturm sends me word of a rumour amongst them concerning Mr. Newton, as if his house and hooks, and all his goods were burnt, and himself so disturbed in mind thereupon as to be reduced to very ill circumstances; which being all false, I thought fit presently to rectify that groundless mistake." — Letter to Waller, Secretary to the Royal Society, quoted by Mr. Edleston from the Letter-book of the Royal Society. See pp. 93 and 97.

[20]

We entirely concur with Mr. Edleston in his opinion that this story refers to an antecedent period. It is obviously a repetition of the story referred to by Dr. Newton respecting the burning of the Optics before 1684.

[21]

In the Journal des Savans, 1832, p. 325, M. Biot has tried to reconcile these facts and dates by arguments which have been so ably exposed and refuted by Mr. Edleston, who entirely concurs with the view I have taken of the subject, that any further controversy is unnecessary. The evidence of Dr. Humphrey Newton leaves no doubt whatever that the fire in Sir Isaac's room took place before 1684. — See Correspondence, &c. pp. lx.-lxlii.

[22]

See Newtoni Opera, tom. iv. p. 480; and Wallisii Opera, 1693, tom. ii. pp. 391-396.

[23]

Optics, part iv. obs. 13.

[24] Dated January 29, 1964.

[25] See p.37

[26]

Gentleman's Magazine, tom. lxxxiv. p. 3, 1814.

[27]

The three first letters above-mentioned have been published by Lord Braybrooke in his Memoirs of Samuel Pepys, vol. ii. pp. 131-135: Lond. 1825. The fourth letter I have given in the APPENDIX, No. IX., in order to complete the published correspondence.

[28]

The system of Hobbes was at this time very prevalent. According to Dr. Bentley, "the taverns and coffee-houses, nay, Westminster Hall, and the very churches, were full of it;" and he was convinced, from personal observation, that "not one English infidel in a hundred was other than a Hobbist."— Monk's Life of Bentley, p. 31.

[29]

Newton and Locke occasionally corresponded on theological subjects. In the autumn of 1702, Newton visited Locke at Oates, and having read his Essay on the Corinthians, he promised to give him his observations and opinion upon it after a more careful perusal. Locke accordingly sent it to him before Christmas 1702; but in consequence of receiving no answer, he wrote to him again on the 30th April 1703, and received his observations in a letter dated May 15, 1703, published by Lord King. In this letter Newton tells him that he had purposed to pay him a visit at Oates, on his way to Cambridge, in summer, but was "now uncertain of this journey." We believe they never met again. Locke died on the 28th October 1704, in the seventy-third year of his age; and it has been stated that Newton visited his tomb at High Laver, in Essex, in all probability when he paid his next visit to Cambridge.

[30]

"The draft of this letter is indorsed J. L. to I. Newton." I have not found the original among Newton's papers.

[31]

The letter of Dr. Mill, dated Nov. 7, 1693, I found among Newton's papers. That of Newton, dated Jan. 29, $169\frac{3}{4}$, is preserved in the library of Queen's College, Oxford, and is No. 26 of the printed Catalogue. Having been kindly favoured with a copy of this letter by Dr. Fox, I have given both of them in the APPENDIX, No. XII., as they possess a peculiar interest.

[32]

"Quoniam varii errores in propositiones 37 et 38 (Lib. 2) irrepsisse, illos omnes restitutos hic apponam, prout in auctoris exemplari inveni, ineunte Maio 1694, dum Cantabrigiæ hærerem, consulendi divini auctoris gratia." — MS. of David Gregory, Rigaud, Hist. Essay/>, p. 100. Mr. Rigaud adds, that this is "the place in which Fatio says he convinced Newton of his mistakes." See Edinburgh Transactions, 1829, vol. xii. p. 71.

[33]

The following account of this affair is given by Mr. Edleston from De la Pryme's Diary: — "On {the} Monday {night} likewise, there being a great number of people at the door {of the haunted house, — it was a house opposite St. John's College, in the occupation of Valentine Austin,} there chanced to come by Mr. Newton, Fellow of Trinity College, a very learned man, and perceiving our Fellows to have gone in {three Fellows of St. John's, with a Fellow Commoner of that College, had rushed in armed with pistols,} and seeing several scholars about the door, 'Oh ye fools!' says he, 'will ye never have any wit? know ye not that all such things are mere cheats and impostures? fie, fie! go home for shame,' and so he left them, scorning to go in." In this Diary, to which we have already referred, there is a full account of the proceedings of the "spirit," which the writer of the Diary had received in a letter from Cambridge. — Edleston's Correspondence, &c., p. lxiv.

[34]

Dr. Gregory concludes his account of this manuscript, which he kindly lent me, in the following words: — "I do not know whether it is true, as stated by Huygens, 'Newtonum incidisse in Phrenitim;' but I think every gentleman who examines this manuscript will be of opinion that he must have thoroughly recovered from his phrenitis before he wrote either the Commentary on the Opinions of the Ancients, or the Sketch of his own Theological and Philosophical Opinions which it contains." An account of this manuscript, by Dr. J. Gregory, has been published in the Edinburgh Transactions for 1829, vol. xii. pp. 64-67. — See Rigaud's Hist. Essay, p. 99.

[35]

This paragraph is as follows: — "Deum esse ens summe perfectum concedunt omnes. Entis autem summe perfecti Idea est ut sit substantia una, simplex, indivisibilis, viva et vivifica, ubique semper necessario existens, summe intelligens omnia, libere volens bona, voluntate efficiens possibilia, effectibus nobilioribus similitudinem propriam quantum fieri potest communicans, omnia in se continens tanquam eorum principium et locus, omnia per presentiam substantialem cernens et regens, et cum rebus omnibus, secundum leges accuratas ut naturæ totius fundamentum et causa constanter co-operans, nisi ubi aliter agere bonum est."