CHAPTER XV.

Xicolas Facio de Duillier attacks Leibnitz—Leibnitz appeals to Ne.wton—He reviews Newtons Quadrature of Curves," and accuses him of Plagiarism—Newtons opinion of the Review—Dr. Keill defends Newton as the true Inventor of Fluxions, and apparently retorts the charge of Plagiarism on Leibnitz, who complains to the Royal Society—Keill explains his Defence—The Royal Society approves of his Explanation —Leibnitz calls Keill an Upstart, and begs the Royal Society to silence him—The Society appoints a Committee to inquire into the Claims of Leibnitz and Newton— The Committee report to the Society, who publish the result in theCommercium Epistolicum"—Instigated by Leibnitz, John Bernoulli attacks the Report, and asserts, in a private letter to Leibnitz, that he was the first Inventor of the new Calculus— Leibnitz circulates this Letter in a Charta Volans, and gives up Bernoulli as the Author of it—Keill replies to this Letter, and attacks Bernoulli as its Author, who solemnly denies it to Newton—Leibnitz attacks Newton in a Letter to the Abb6 Conti—Newton replies to it—The Controversy excites great interest—Leibnitz urges Bernoulli to make a Public Declaration in his favour—Bernoulli sends to Leibnitz the celebrated Letter Pro Eminente Mathfmatico," en condition of his Name being kept secret—Leibnitz and Wolf alter this Letter improperly, and publi>h it in such a form, that Bernoulli is proved to be its Author—Bernoulli is annoyed by the discovery, and endeavours, by improper means, to evade the truth—The Abbg Varignon reconciles Newton and Bernoulli—Death of Leibnitz—Newton writes a History of the Calculus—General view of the Controversy, and of the conduct of the parties.

Nicolas Facio de Duilliee, a Genevese by birth, came to England in the spring of 1687, and, with the exception of a visit to Switzerland in 1699, 1700, and 1701, remained there during the rest of his life. He had become acquainted with the celebrated Huygens at the Hague in 1686, and had attained

VOL. IT. A



Z LIFE OF SIR ISAAC XEWTON. CHAP. XV.

to such a proficiency in mathematics, that he was introduced to Sir Isaac Newton, and visited him at Cambridge in the month ^of November 1692. Though only in the 28th year of his age, his health was precarious, and he seems to have consulted Newton on the subject of his spiritual as well as of his bodily condition. On his return from Cambridge, he caught a severe cold, which affected his lungs, and gave him great alarm. In communicating to Sir Isaac an account of his symptoms, he says, I thank God that my soul is extremely quiet, in which you have had the chief hand;" and fearing that his illness would prove fatal, he expresses the wish that his eldest brother, a man of an extraordinary integrity, shoidd succeed him in his friendship." Sir Isaac answered this letter in course of post, making inquiries about his brother, and telling Facio that he remembered him in his prayers. In his reply, Facio gave him his most humble thanks, both for his prayers and his kindness,—requested him thus to remember him as long as he lived, and assured him that he always remembered him in a similar manner.^

1 Nicolas Facio de Duillier, an eminent mathematician, was bom at Basle on the 16th February 1664. In 1684 and 1685 he became acquainted with Count Fenil, a Pied-montese, who, having incurred the displeasure of the Duke of Savoy, took refuge in France, where he became captain of a troop of horse. Having quarrelled one day with the commanding officer of his regiment, when drawn up on parade, the Count shot him dead, and, being well mounted, escaped from his pursuers. He fled to Alsace, where he took refuge in the house of Mr. Facios maternal grandfather; but, in order to assist him more eflFectually, he was sent to the house of Facios father, who lived at Duillier. When walking alone with young Facio, the Count told him that he bad offered to M. De Louvois to seize the Prince of Orange, and deliver him into