MACLAURIN (Co /./ NO in biography, a most eminent mathematician and phi losopher, was the son of a clergyman, and born at Kilmoddan in Scotland, in the year 1698. Ile was sent to the university of Glasgow in 17v9; where lie continued five years, and applied to his studies in a very intense manner, and particularly to the mathematics. His great genius for mathematical learning discovered itself so early as twelve years of age ; when, having accidentally met with a copy of " Euclid's aements" in a friend's cham ber, he became in a few days master of the first six books without any assistance; and, it is certain, that in his sixteenth year he had invented many of the propo sitions which were afterwards published as part of his work, entitled, " Geome trix Organica." In his fifteenth year he took the degree of Master of Arts ; on which occasion he composed, and pub licly defended, a thesis on the power of gravity, with great applause. After this he quitted the university, and retired to a country seat of his uncle, who had the care of his education ; his parents being dead some time. Here he spent two or three years in pursuing his favourite stu dies; but in 1717, at nineteen years of age only, he offered himself a candidate for the professorship of mathematics in the Marischal College of Aberdeen, and ob tained it after a ten day's trial, against a very able competitor.
In 1719, Mr. Maclaurin visited London, where he left his " Geometria Organica" to print, and where he became acquainted with Dr. Hoadley, then bishop of Bangor, Dr. Clarke, Sir Isaac Newton, and other eminent men , at which time also he was admitted a member of the Royal Society ; and in another journey in 1721, he con tracted an intimacy with Martin Folkes, Esq. the president of it, which continued during his w hole life.
In 1722, Lord Polworth, plenipoten tiary of the King of Great Britain at the congress of Cambray, engaged Maclaurin to go as a tutor and companion to his eldest son, who was then to set out on his travels. After a short stay at Paris, and visiting other towns in France, they fixed in Lou rain, where he wrote his piece on the percussion of bodies, which gained him the prize of the Royal Academy of Sciences for the year 1724. But his pupil dying soon after at Montpelier, he re turned immediately to his profession at Aberdeen. He was hardly settled here when he received an invitation to Edin burgh; the curators of that university being desirous that he should supply the place of Mr. James Gregory, whose great age and infirmities had rendered him in capable of teaching. He had here some
difficulties to encounter, arising from competitors, who had good interest with the patrons of the university, and also from the want of an additional fund for the new professor ; which, however, at length were all surmounted, principally by the means of Sir Isaac Newton. Ac cordingly, in November 1725, he was in troduced into the university, as was at the same time his learned colleague and intimate friend, Dr. Alexander Munro, professor of anatomy. After this, the mathematical classes soon became very numerous, there being generally upwards of one hundred students attending his lectnres every year ; who being of differ ent standings and proficiency, he was obliged to divide them into four or five classes, in each of which he employed a full hour every day, from the first of No vember to the first of June. In the junior class he taught the first six books of " Eu clid's Elements," plane trigonometry, practical geometry, the elements of forti fication, and an introduction to algebra. The second class studied algebra, with the eleventh and twelfth books of Euclid, spherical trigonometry, conic sections, and the general principles of -astronomy. The third went on in astronomy and per spective, read a part of " Newton's Prin. cipia," and had perfilmed a course of experiments for illustrating them ; he af terwards read and demonstrated the ele ments of fluxions. Those in the fourth class read a system of fluxions, the doc trine of chances, and the remainder of "Newton's Principia." In 1734, Dr. Berkley, Bishop of Cloyne, published a piece called the " Analyst," in which betook occasion, from some dis putes that had arisen concerning the grounds of the fluxionary method, to ex plode the method itself ; and also to charge mathematicians in general with infidelity in religion. Maclaurin thought himself included in this charge, and be gan an answer to Berkley's book ; but other answers coming out, and as be proceeded, so many discoveries, so many new theories and problems occurred to him, that instead or a vindicatory pam phlet, he produced a complete system of fluxions, with their application to the most considerable problems in geometry and natural philosophy. This work was published at Edinburgh in 1742, 2 vols. 4to.; and as it cost him infinite pains, so it is the most considerable of all his works, and will do him immortal ho. nour, being indeed the most complete treatise on that science that has yet ap peared.