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324 family directing his attention to the beauty of the fruit of the Siberian crab, when he found himself unable to distinguish the scarlet fruit from the green leaves of the tree. One of the rules by which he guided himself in literary matters, was never to publish anything anonymously: a rule which, if generally observed, would probably save the world the reading of much inferior and much vicious composition.

STEWART, (, an eminent geometrician, and professor of mathematics in the university of Edinburgh, was born at Hothsay, in the island of Bute,—of which his father, the reverend Mr Dugald Stewart, was minister,—in the year 1717. On finishing his course at the grammar school, he was entered at the university of Glasgow in 1734. At college, he became acquainted with Dr Hutcheson and Dr Simson. In the estimation of the latter, he rose, in after life, from the rank of a favourite pupil, to that of an esteemed friend. They were long intimate personal companions, admired the same branches of their common science, and exhibited in their works symptoms of mutual assistance. It is said, indeed, that we are indebted to the friendship and acuteness of Simson, for the suggestion of mathematics as a study suited to the genius of Stewart. At all events, there is every reason to suppose that the love of the latter for the geometry of the ancients, was derived from his intercourse with his instructor. While attending the lectures of Dr Gregory in Edinburgh, in 1741, the attractions of the new analysis were not sufficient to make him neglect his favourite study; and he communicated to his friend his discoveries in geometry, receiving similar communications in return. While Simson was conducting the laborious investigations, which enabled him to-revive the porisms of the ancients, Stewart received the progressive benefit of the discoveries, long before they were communicated to the world; and while he probably assisted his friend in his investigations, he was enabled, by investigating the subject in a new direction, to publish, in 1746, his celebrated series of propositions, termed " General Theorems." "They are," says the author's biographer, "among the most beautiful, as well as most general propositions known in the whole compass of geometry, and are perhaps only equalled by the remarkable locus to the circle in the second book of Apollonius, or by the celebrated theorems of Mr Cotes. The first demonstration of any considerable number of them, is that which was lately communicated to this society [the Royal Society of Edinburgh]; though I believe there are few mathematicians, into whose hands they have fallen, whose skill they have not often exercised. The unity which prevails among them, is a proof that a single, though extensive view, guided Mr Stewart in the discovery of them all."

Meanwhile, Mr Stewart had become a licentiate of the church of Scotland; and through the joint influence of the earl of Bute and the duke of Argyle, had obtained the living of Roseneath. The "General Theorems" made their appearance at a time when they were calculated to have a considerable effect on the prospects of the author. In the summer of 1746, the mathematical chair of Edinburgh became vacant, by the death of Mr Maclaurin. Stewart was not at that period known to the learned world; and Mr Stirling, a gentleman of well known reputation, was requested to become the new professor. This gentleman declined the situation; and, towards the end of the year, when the patrons of the university were looking for another candidate worthy of the important duty, Stewart's book was published. The author was readily offered the situation, which he accepted. "The duties of this office," says his biographer, "gave a turn somewhat different to his mathematical pursuits, and led