ton himself, who had given him a defiance in express terms.

Leibnitz was not long in complying with this request. He addressed a letter to the Abbé Conti, dated April 9th, 1716, but he sent it through M. Ramond at Paris, to communicate it to others. When it was received by the Abbé Conti, Newton wrote observations upon it, which were communicated only to some of his friends, and which, while they placed his defence on the most impregnable basis, at the same time threw much light on the early history of his mathematical discoveries.

The death of Leibnitz on the 14th November, 1716, put an end to this controversy, and Newton some time afterward published the correspondence with the Abbé Conti, which had hitherto been only privately circulated among the friends of the disputants.*

In 1722, a new edition of the Commercium Epistolicum was published, and there was prefixed to it a general review of its contents, which has been falsely ascribed to Newton. When the third edi

* M. Biot remarks, that the animosity of Newton was not calmed by the death of Leibnitz, for he had no sooner heard of it than he caused to be printed two manuscript letters of Leibnitz, written in the preceding year, accompanying them with a very bitter refutation (en les accompagnant d'un refutation tres-amere). Who that reads this sentence does not believe that the bitter refutation was written after Leibnitz's death? The animosity could not be shown by the simple publication of the letters. It could reside only in the bitterness of the refutation. The implied charge is untrue; the bitter refutation was written before Leibnitz's death, and consequently he showed no animosity over the grave of his rival; and in our opinion none even before his death.

†M. Biot states that Sir Isaac Newton caused this edition of the Commercium Epistolicum to be printed; that Sir Isaac placed at the head of it a partial abstract of the collection; and that this abstract appeared to have been written by himself. These groundless charges may be placed, without any refutation, beside the assertion of Montucla, that Newton wrote the notes (les notes) on the Commercium Epistolicum; and the equally incorrect statement of La Croix, that Newton added to it notes (des notes), with his own hand. We should not have noticed the charges of M. Biot, had he not adduced them as proofs of Newton's animosity to Leibnitz after his death. See Mr. Herschel's History of Mathematics in the Edinburgh Encyclopædia vol. xiii. p. 368, note.

tion of the Principia was published in 1725, the celebrated scholium which we have already quoted, and in which Leibnitz's differential calculus was mentioned, was struck out either by Newton or by the editor. This step was perhaps rash and illadvised; but as the scholium had been adduced by Leibnitz and others as a proof that Newton acknowledged him to be an independent inventor of the calculus, an interpretation which it does not bear, and which Newton expressly states he never intended it to bear, he was justified in withdrawing a passage which had been so erroneously interpreted, and so greatly misapplied.

In viewing this controversy, at the distance of more than a century, when the passions of the individual combatants have been allayed, and national jealousies extinguished, it is not difficult to form a correct estimate of the conduct and claims of the two rival analysts. By the unanimous verdict of all nations, it has been decided that Newton invented fluxions at least ten years before Leibnitz. Some of the letters of Newton which bore reference to this great discovery were perused by the German mathematician; but there is no evidence whatever that he borrowed his differential calculus from these letters. Newton was therefore the first inventor, and Leibnitz the second. It was impossible that the former could have been a plagiarist; but it was possible for the latter. Had the letters of Newton contained even stronger indications than they do of the new calculus, no evidence short of proof could have justified any allegation against Leibnitz's honour. The talents which he displayed in the im provement of the calculus showed that he was capable of inventing it; and his character stood sufficiently high to repel every suspicion of his integrity. But if it would have been criminal to charge Leibnitz with plagiarism, what must we think of those who dared to accuse Newton of bor

rowing his fluxions from Leibnitz? This odious accusation was made by Leibnitz himself, and by Bernouilli; and we have seen that the former repeated it again and again, as if his own good name rested on the destruction of that of his rival. It was this charge against Newton that gave rise to the attack of Keill, and the publication of the Commercium Epistolicum; and, notwithstanding this high provocation, the committee of the Royal Society contented themselves with asserting Newton's priority, without retorting the charge of plagiarism upon his rival.

Although an attempt has been recently made to place the conduct of Leibnitz on the same level with that of Newton, yet the circumstances of the case will by no means justify such a comparison. The conduct of Newton was at all times dignified and just. He knew his rights, and he boldly claimed them. Conscious of his integrity, he spurned with indignation the charge of plagiarism with which an ungenerous rival had so insidiously loaded him; and if there was one step in his frank and unhesitating procedure which posterity can blame it is his omission, in the third edition of the Principia, of the references to the differential calculus of Leibnitz. This omission, however, was perfectly just. The scholium which he had left out was a mere historical statement of the fact, that the German mathematician had sent him a method which was the same as his own; and when he found that this simple assertion had been held by Leibnitz and others` as a recognition of his independent claim to the invention, he was bound either to omit it altogether, or to enter into explanations which might have involved him in a new controversy.

The conduct of Leibnitz was not marked with the same noble lineaments. That he was the aggressor is universally allowed. That he first dared to breathe the charge of plagiarism against Newton, and that he often referred to it, has been sufficiently

When

apparent; and when arguments failed him he had recourse to threats-declaring that he would publish another Commercium Epistolicum, though he had no appropriate letters to produce. All this is now matter of history; and we may find some apology for it in his excited feelings, and in the insinuations which were occasionally thrown out against the originality of his discovery; but for other parts of his conduct we seek in vain for an excuse. he assailed the philosophy of Newton in his letters to the Abbé Conti, he exhibited perhaps only the petty feelings of a rival; but when he dared to calumniate that great man in his correspondence with the Princess of Wales, by whom he was respected and beloved; when he ventured to represent the Newtonian philosophy as physically false, and as dangerous to religion; and when he founded these accusations on passages in the Principia and the Optics glowing with all the fervour of genuine piety, he cast a blot upon his name, which all his talents as a philosopher, and all his virtues as a man, will never be able to efface.

CHAPTER XIII.

James II. attacks the Privileges of the University of Cambridge-Newton chosen one of the Delegates to resist this Encroachment-He is elected a Member of the Convention Parliament-Burning of his Manuscripts-His supposed Derangement of Mind-View taken of this by foreign Philosophers-His Correspondence with Mr. Pepys and Mr. Locke at the time of his Illness-Mr. Millington's Letter to Mr. Pepys on the subject of Newton's Illness-Refutation of the Statement that he laboured under Mental Derangement.

FROM the year 1669, when Newton was installed in the Lucasian chair, till 1695, when he ceased to reside in Cambridge, he seems to have been seldom absent from his college more than three or four

weeks in the year. In 1675, he received a dispensation from Charles II. to continue in his fellowship of Trinity College without taking orders, and we have already seen in the preceding chapter how his time was occupied till the publication of the Principia in 1687.

An event now occurred which drew Newton from the seclusion of his studies, and placed him upon the theatre of public life. Desirous of re-establishing the Catholic faith in its former supremacy, King James II. had begun to assail the rights and privileges of his Protestant subjects. Among other illegal acts, he sent his letter of mandamus to the University of Cambridge to order Father Francis, an ignorant monk of the Benedictine order, to be received as master of arts, and to enjoy all the privileges of this degree, without taking the oaths of allegiance and supremacy. The university speedily perceived the consequences which might arise from such a measure. Independent of the infringement of their rights which such an order involved, it was obvious that the highest interests of the university were endangered, and that Roman Catholics might soon become a majority in the convocation. They therefore unanimously refused to listen to the royal order, and they did this with a firmness of purpose which irritated the despotic court. The king reiterated his commands, and accompanied them with the severest threatenings in case of disobedience. The Catholics were not idle in supporting the views of the sovereign. The honorary degree of M.A. which conveys no civil rights to its possessor, having been formerly given to the secretary of the ambassador from Morocco, it was triumphantly urged that the University of Cambridge had a greater regard for a Mahometan than for a Roman Catholic, and was more obsequious to the ambassador from Morocco than to their own lawful sovereign. Though this reasoning might impose upon the ignorant, it pro