they had lost one of the truest representatives of the national spirit and character, as well as one of the ablest and most valuable writers that had ever adorned the national literature. His posthumous works were a volume of pulpit lectures on the Book of Esther; a volume of sermons, some of them of great excellence; and a volume of miscellaneous writings—all edited by his eldest son, Dr. Thomas M'Crie, who published also a full and valuable Life.—P. L.
M'CULLAGH, James, M.R.I.A., one of the most eminent mathematicians and physicists of his day, was born near Strabane in Ireland in the year 1809. He entered Trinity college, Dublin, in November, 1814, as a pensioner; and the following year he obtained a sizarship. Throughout his undergraduate course he was eminently successful, both in classics and science. In 1827 he was elected a scholar, and in 1832 he obtained a fellowship. In 1833 he was elected a member of the Royal Irish Academy, and in 1838 was put upon the council; and from 1844 to 1846 filled the office of secretary to that body. The chair of natural philosophy in the university becoming vacant in 1843, M'Cullagh was elected to it without opposition. From an early age he was a distinguished scientific investigator. While yet an undergraduate he had completed a new and original theory of the rotation of a solid body round a fixed point, which he was preparing for publication when he was anticipated by Poinsot, who published a very elegant tract on the subject. By this theory M'Cullagh completely solved the case of a body abandoned to its own motion, on receiving a primitive impulse in any direction, under the action of no accelerating forces. He next turned his attention to the wave theory of light, in which he afterwards became so eminent. On this subject he communicated his first paper to the Academy in June, 1830, followed by one on the "Rectification of the conic sections." M'Cullagh's first entirely original paper was read to the Academy, February 22, 1836. In it he linked together, by a single and simple mathematical hypothesis, the peculiar unique laws which govern the motion of light in its propagation through quartz. A further advance on the subject of light was communicated in a paper, "On the laws of crystalline reflection and refraction," in January, 1837, resolving the problem—partially solved by Fresnel—and reducing it to geometrical laws of the greatest simplicity and elegance. The originality of this discovery was contested by Neumann of Königsberg; but M'Cullagh vindicated beyond all doubt his own claim; and unquestionably results of greater importance, were arrived at by M'Cullagh. Both had set out independently from the same principles, and both solved the question analytically; but the geometrical interpretation of the laws had been given by M'Cullagh only. Other valuable papers on the subject of light followed at intervals; and he also produced highly original papers on purely mathematical subjects; amongst others, one on "Surfaces of the second order." M'Cullagh received in 1838 the Cunningham medal of the Academy for his essay on the "Laws of crystalline reflection and refraction." In 1846 the Royal Society awarded him the Copley medal for his investigations in the theory of light. As professor of natural philosophy M'Cullagh gave a great impetus by his lectures to the study of the severer sciences. "It was in the delivery of them," says a high authority, "that Professor M'Cullagh used to display the extensive information, the elaborate research, and the vast acquired treasures of his highly-cultivated mind. . . . Nothing could exceed the depth, or surpass the exquisite taste and elegance of all his original conceptions, both in analysis and in the ancient geometry in which he delighted." In his investigations on the dynamical theory of light—"the unaided creation of his own surpassing genius—he has reared the noblest fabric which has ever adorned the domains of physical science, Newton's system of the universe alone excepted." M'Cullagh had a high appreciation of every branch of knowledge, and was a munificent patron of Irish antiquities. In private life he was unobtrusive, modest, and utterly unselfish; charitable, generous, and religious. Severe mental application produced bodily and mental derangement; and in a moment of aberration he put an end to his life on the 24th of October, 1847.—J. F. W.
M'CULLOCH, Horatio, R.S.A., an eminent Scottish landscape painter, son of a manufacturer in Glasgow, was born there in 1806. At the age of twenty-three, after studying his art devotedly in his native city and in Edinburgh, he exhibited a "View on the Clyde," and from that time continued to contribute to the annual exhibitions of the Scottish Academy some of their most attractive pictures. Elected an associate of the academy in 1836, two years afterwards he became a member. During that period he resided in Hamilton, studying the scenery of Cadzow forest, a "View" in which, exhibited in 1838, attracted great attention. M'Culloch from that time resided in Edinburgh. His fame steadily increased, and as a painter of romantic Scottish scenery he was unrivalled. He died on the 24th of June, 1867.
M'CULLOCH, John, an English physician and distinguished geologist, was born in Guernsey in 1773. His early education was received in Cornwall, whence he removed to Edinburgh to study medicine. He obtained his degree of M.D. at the early age of eighteen, and soon after received an appointment as assistant-surgeon in the army. He served for some years in the artillery, but in 1807 established himself in private practice at Blackheath. On occasional visits made to his father who had settled in Cornwall, he had made the acquaintance of Sir Humphrey Davy, whose advice was of great use to him in his chemical studies. Some years afterwards he was employed by government in a mineralogical and geological survey of Scotland, a work which was only brought to a conclusion in 1832. In 1820 he was appointed physician in ordinary to Prince Leopold, and held till the time of his death the professorship of chemistry and geology in the East India Company's military school at Addiscombe. He died in Cornwall in 1835, in consequence of an accident. M'Culloch was remarkable for the versatility of his powers. Thanks to assiduous labour and an extraordinary memory, he acquired an extensive knowledge of geology, mineralogy, chemistry, mathematics, the natural sciences, and industrial arts He was besides a draughtsman, architect, and musician. His greatest work, perhaps, is his "Highlands and Western Islands of Scotland," of which it has been said it has never been surpassed, scarcely even equalled, by any work of a similar kind.—W. B—d.
M'CULLOCH, John Ramsay, an eminent political economist, was born in Wigtonshire in 1789. He was a contributor to the Edinburgh Scotsman during its early years, and also to the Edinburgh Review; of the former he was for a period editor. From the knowledge of political economy displayed in his writings he was twice appointed to deliver the Ricardo lectures in London; and in a criticism in the Edinburgh Review for November, 1825, on his "Discourse on the rise, progress, &c., of political economy," published the same year, he was recommended as a very fit person to fill a separate chair of political economy in the university of Edinburgh. Such a chair was not instituted; but in 1828 Mr. M'Culloch was appointed professor of political economy in the university of London, and held the post until 1832. In 1838 he became comptroller of the stationery-office. Of his numerous contributions to political economy, statistics, &c., among the more important are—the "Principles of Political Economy," 1825; the valuable "Dictionary of Commerce," 1834; the "Statistical Account of the British Empire," 1837; and, "Dictionary, geographical, statistical, and historical, of the world," 1842; the "Treatise on Taxation and the Funding System," 1845; and the "Literature of Political Economy," 1845—a very useful contribution to the bibliography and biography of his favourite science. Most of these works have gone through several editions. In 1853 Mr. M'Culloch collected his "Treatises and Essays on subjects connected with economical policy," 2nd edition, 1859. Among his latest works are the elaborate treatises on "Money" and "Taxation," contributed to the eighth edition of the Encyclopædia Britannica, and republished separately. He edited, with a life of the author, the works of Ricardo; with supplemental dissertations, Adam Smith's Wealth of Nations; and the volumes of scarce early English tracts on trade, &c., privately printed by Lord Overstone. In the great controversy on the corn-laws Mr. M'Culloch advocated a moderate fixed duty on corn. He died on the 11th of November, 1864.—F. E.
MACDIARMID, John, an unfortunate literary Scotchman, who fills a niche in the elder D'Israeli's Calamities of Authors, was the son of a Perthshire minister, and born in 1779. He studied at Edinburgh and St. Andrews, was tutor in a gentleman's family, and in 1801 repaired to London to become an author by profession. He contributed to periodicals; edited the St. James' Chronicle, then a journal of note; and in 1803 published an "Inquiry into the system of military defence of Great Britain," pointing out the defects of the volunteer system, and followed in 1804 by an "Inquiry into the nature of civil and
