disinterested Mr. Newton was in search after truth. In 1667, he was chosen fellow of his college, and the same year took his master's degree. In 1669, Dr. Barrow resigned to him the mathema tical chair, and his lectures, for three years, were upon his discoveries in optics; in the course of which he brought to perfection his theory of light and colours, the hint of which he is said to have obtained from seeing a child blowing bubbles of soap and water with a tobacco pipe. In 1680 he made several astronomical observations upon the comet which appeared that year, and which, for some time, he took to be not one and the same, but two different comets. He was at a great uncertainty about this, when he received a letter from Mr. Hooke, on the nature of the line described by a falling body, supposed to be moved circularly by the diurnal motion of the earth, and perpendicularly by the power of gravity. This led him to enquire what was the real figure in which such a body moved; and as Picart had, not long before, (viz. in 1679) measured a degree of the earth with sufficient accuracy, by using his measures, that planet appeared to be retained in her orbit by the sole power of gravity, and consequently this power decreases in the duplicate proportion of the distance, as he had formerly conjectured: upon this principle he found the line described by a falling body to be an ellipsis, of which.the centre of the earth earth is one focus. And finding by these means that the primary planets really moved in such orbits as Kepler had supposed, he had the satisfaction to find the result of his enquiries answer some valuable purposes: accordingly he drew up some propositions relative to the motion of the primary planets round the sun, which were communicated to the Royal Society in 1683, and were, with much solicitation on their part, printed four years afterwards at their expense, under the title of Philosophie naturalis Principia Mathematica, containing, in the third book, what is now denominated his cometic astronomy, or rather his system of the world. This immortal treatise, full of the profoundest investigations and discoveries, arose from only a few propositions at first casually advanced. A second edition, with additions, appeared at Cambridge in quarto, in 1713. This book, in which the author, built a new system of natural philosophy upon the most sublime geometry, did not at first meet with all the applause it deserved, and which it was one day to receive, owing principally to the hold which the Cartesian system had obtained in the world, and the conciseness with which our philosopher's performance was drawn up, so that the ablest mathematicians were obliged to study it with great care before they could become masters of its principles. But when its worth was sufficiently known, the approbation, which had been slowly obtained, was universal; and nothing was to be heard in all quarters, but one general shout of admiration. "Does Mr. Newton eat, drink, or sleep, like other men ?" (said the Marquis de l'Hôpital, one of the greatest mathematicians of the age, to the Englishmen who visited him.) "I represent him to myself as a celestial genius, entirely disengaged from matter." It is beside our purpose to enter into any thing like a regular biography of this wonderful man. We shall therefore briefly notice only the leading points of his life. So highly was he esteemed by the University of Cambridge, that when their rights were attacked by James the second, Mr. Newton was appointed one of their delegates to the High Commission Court; when he made so ingenious a defence, that the king thought proper to drop the affair, and to continue their pri vileges. In 1688, Mr. Newton was chosen, by the University, one of their members for the Convention Parliament, in which he sat till its dissolution. His colleague was Mr. Charles Montague, afterwards Earl of Halifax, by whose means Mr. Newton was appointed Warden of the Mint. In this office he rendered essential service to the nation, on the recoining of the money, as he also did when he was made Master of the Mint, in 1699. In a late valuable work, "On the Coins of the Realm," by the Earl of Liverpool, is the following article, respecting this great man: "In 1717, not twenty years after the re-coinage, the ministers of George I. were alarmed at the decrease of the silver coins, and applied to Sir Isaac Newton, then master of the mint, for his advice. He stated that the guinea, which then passed for 21s. 6d. was worth only about 20s. 8d. according to the relative value of gold and silver in the bullion market; and he suggested, as an experiment, that 6d. should be taken off the current value of the guinea, in order to diminish the temptation to melt down and export the silver coins. At the same time, he acknowledged that 10d. or 12d. ought to be taken off the value of the guinea, in order that the gold coins might bear the same relation to the silver, as they ought to do, according to the course of exchange throughout Europe; although it might be better to wait the effect of the measure he proposed, which would shew what further reduction would be most convenient for the public. "In consequence of this advice, the current value of the guinea was lowered, and it was ordered to be legal tender, at the rate of 21s. at which value it continues." Upon his promotion to the mastership of the Mint, worth about twelve hundred pounds a year, Mr. Newton appointed Mr. William Whiston his assistant in the professorship at Cambridge, giv ing him the full profits of the place, and soon afterwards he resigned the chair entirely to him.* In This ingenious, but eccentrick character, though a dogmatist, and a heretick, was, at the same time the most credulous and superstitious man alive. He was not contented with explaining the principles of Astronomy upon the Newtonian system, in his lectures at Cambridge, but he must go out of his way to attack the Athanasian Creed, and other formularies of the established church. This provoked the heads of the University so much, that at last Whiston was deprived of his professorship and expelled, by a decree of the senate. Sir Isaac, though he pitied the man, was displeased with his conduct; and Whiston, in the extraordinary memoirs which he has given of his own life, and which are full of the most insufferable egotism, has abused his old friend and patron, "as being the most fearful, cautious, and suspicious. temper that he ever knew. And had he been alive," says this vain old man, "when I wrote against his Chronology, and so thoroughly confuted it, that nobody has ever ventured to vindicate it, that I know of, since my confutation was published, I should not have ventured to publish it during his life time; because I knew his temper so well, that I should have expected it would have killed him." Poor Whiston, who thought himself more than a match for Newton, was himself the dupe of the weakest extravagancies. He placed the Apostolical Constitutions, a set of canons, with out authority, upon a footing with the Scriptures, and by literally expounding the prophecies, he came to foretel the exact time when the Millennium was to begin, but happening to outlive that period, and his prediction not being accomplished, he wisely put it off for about twenty years longer. Upon this the following story has been told, that having a small |