ROGERS, James Blythe, chemist, born in Philadelphia, Pennsylvania, 11 February, 1802; died there, 15 June, 1852. He was the eldest son of Patrick Kerr Rogers, who was graduated at the medical department of the University of Pennsylvania in 1802, and in 1819 was elected professor of natural philosophy and mathematics at William and Mary, where he remained until his death. James was educated at William and Mary, and, after preliminary studies with Dr. Thomas E. Bond, received the degree of M.D. from the University of Maryland in 1822. Subsequently he taught in Baltimore, but soon afterward settled in Little Britain, Lancaster County, Pennsylvania, and there practised medicine. Finding this occupation uncongenial, he returned to Baltimore and became superintendent of a large manufactory of chemicals. He devoted himself assiduously to the study of pure and applied chemistry, and became professor of that branch in Washington medical college, Baltimore, also lecturing on the same subject at the Mechanics' institute. In 1835 he was called to the same chair in the medical department of Cincinnati college, where he remained until 1839, spending his summer vacations in field-work and chemical investigations in connection with the geological survey of Virginia, which was then under the charge of his brother William. In 1840 he settled permanently in Philadelphia, where he became an assistant to his brother Henry, at that time state geologist of Pennsylvania, and in 1841 he was appointed lecturer on chemistry in the Philadelphia medical institute, a summer school. He was elected professor of general chemistry at the Franklin institute in 1844, and held that chair until his election in 1847 to succeed Robert Hare as professor of chemistry in the University of Pennsylvania. Professor Rogers was a representative at the National medical convention in 1847, and a delegate to the National convention for the revision of the United States Pharmacopoeia in 1850, and a member of various learned societies. He contributed papers to scientific journals, and with his brother Robert prepared the seventh edition of Edward Turner's "Elements of Chemistry" and William Gregory's "Outlines of Organic Chemistry," in one volume (Philadelphia, 1846). See "Memoir of the Life and Character of James B. Rogers," by Dr. Joseph Carson (Philadelphia, 1852). --His brother, William Barton, geologist, born in Philadelphia, Pennsylvania, 7 December, 1804; died in Boston, Massachusetts, 30 May, 1882, was educated by his father and at William and Mary. In 1827 he delivered a series of lectures on science before the Maryland institute, and in 1828 he succeeded his father in the chair of physics and chemistry at William and Mary, where he remained for seven years. At this time he carried on investigations on dew and on the voltaic battery, and prepared a series of papers on the green sand and calcareous marl of eastern Virginia and their value as fertilizers. He then accepted the professorship of natural philosophy and geology in the University of Virginia, where he remained until 1853, attaining a high reputation as a lecturer. In 1835 he was called upon to organize the geological survey of Virginia, mainly in consequence of his printed papers and addresses. His brother, Henry D. Rogers, was at that time state geologist of Pennsylvania, and together they unfolded the historical geology of the great Appalachian chain. Among their joint special investigations were the study of the solvent action of water on various minerals and rocks, and the demonstration that coal-beds stand in close genetic: relation to the amount of disturbance to which the inclosing strata have been submitted, the coal becoming harder and containing less volatile matter as the evidence of the disturbance increases. Together they published a paper on "The Laws of Structure of the more Disturbed Zones of the Earth's Crust," in which the wave theory of mountain-chains was first, announced. This was followed later by William B. Rogers's statement of the law of distribution of faults. In 1842 the work of the survey closed, and meanwhile he had published six " Reports of the Geological Survey of the State of Virginia" (Richmond, 1836-'40), which have since been edited and issued in one volume as "Papers on the Geology of Virginia" (New York, 1884). He resigned his professorship at the University of Virginia in 1853, and removed to Boston, where he became active in the scientific movements under the auspices of the Boston society of natural history and the American academy of arts and sciences, in whose proceedings and the "American Journal of Science " his papers of this period were published. About 1859 he began to interest the people of Boston in his scheme for technical education, in which he desired to have associated, on one side research and investigation on the largest scale, and on the other agencies for the popular diffusion of useful knowledge. This project continued to occupy his attention until in 1865 it culminated in the organization of the Massachusetts institute of technology, of which he became first president. Three years later, failing health made it necessary for him to relinquish that office, which he resumed in 1878; but he gave it up again in 1881, and was made professor emeritus of physics and geology, which chair he had held in connection with the presidency. He delivered a course of lectures before the Lowell institute on "The Application of Science to the Arts" in 1862, and in 1861 had been appointed inspector of gas and gas-meters for the state of Massachusetts. Harvard gave him the degree of LL.D. in 1866. Professor Rogers was chairman of the American association of geologists and naturalists in 1845 and again in 1847, also calling to order the first meeting of the American association for the advancement of science, of which body he was president in 1875, and elected its first honorary fellow in 1881, as a special mark of distinction. He was active in founding the American social science association and its first president; also he was one of the corporate members of the National academy of sciences, and its president from 1878 until his death. Besides numerous papers on geology, chemistry, and physics, contributed to the proceedings of societies and technical journals, he was the author of "Strength of Materials" (Charlottesville, 1838) and "Elements of Mechanical Philosophy" (Boston, 1852). --Another brother, Henry Darwin, geologist, born in Philadelphia, Pennsylvania, 1 August, 1808; died near Glasgow, Scotland, 29 May, 1866, was educated in Baltimore, Maryland, and Williamsburg, Virginia, and in 1830 was elected professor of chemistry and natural philosophy at Dickinson college, Pennsylvania In 1831 he went to Europe and studied science in London. During the winter of 1833-'4 he delivered a course of lectures on geology at the Franklin institute, and in 1835 he was elected professor of geology and mineralogy at the University of Pennsylvania, where he remained until 1846. In 1835 he was chosen to make a geological and mineralogical survey of New Jersey, and, in addition to a preliminary report in 1836, he published "Description of the Geology of the State of New Jersey" (Philadelphia, 1840). On the organization of the geological survey of the state of Pennsylvania in 1836, he was appointed geologist in charge, and engaged in active field-work until 1841, when the appropriations were discontinued. During the ten ensuing years his services were retained as an expert by various coal companies, but the field-work of the survey was resumed in 1851 and continued until 1854. Six annual reports were published between 1836 and 1842, and in 1855 the preparation of a final report was confided to him Finding that the work could be done less expensively abroad, he transferred his residence to Edinburgh and issued "The Geology of Pennsylvania, a Government Survey" (2 vols., Edinburgh, 1858). In 1858 he was appointed professor of natural history in the University of Glasgow, and he continued in that chair until his death. Professor Rogers also delivered a series of lectures on geology in Boston during 1844. He received the degree of A. M. from the University of Pennsylvania in 1834, and that of LL. D. from the University of Dublin in 1857. During his residence in Philadelphia he was active in the American philosophical society and in the Philadelphia academy of natural sciences, and he was a member of other American societies, and of the Geological society of London, a fellow of the Royal society of Edinburgh, and president of the Philosophical society of Glasgow in 1864-'6. He edited "The Messenger of Useful Knowledge" in 1830-'1, and later was one of the conductors of the "Edinburgh New Philosophical Journal." His published papers are about fifty in number, and pertain chiefly to geology. In addition to his geological reports, he published "A Guide to a Course of Lectures in Geology," and is the author of a geological map of the United States and a chart of the arctic regions in the "Physical Atlas." In conjunction with William and Alexander K. Johnson, he published a geographical atlas of the United States (Edinburgh, 1857).--Another brother, Robert Elnpie, chemist, born in Baltimore, Maryland, 29 March, 1813 ; died in Philadelphia, Pennsylvania, 6 September, 1884, was educated first under the care of his father, and then by his elder brothers. It was intended that he should be a civil engineer, and for a time he acted as assistant in the survey of the Boston and Providence railroad, but he abandoned this in 1833, and was graduated at the medical department of the University of Pennsylvania in 1836, where he followed a full course of chemistry under Robert Hare. The active practice of medicine not being congenial to him, he was appointed chemist to the geological survey of Pennsylvania in 1836, and continued so for six years. In 1841-'2 he was temporary instructor in chemistry at the University of Virginia and was elected, in March, 1842, to the chair of general and applied chemistry and materia medica in that institution. He continued in this place until 1852, when he was called to succeed his brother James as professor of chemistry at the University of Pennsylvania, where he became dean of the medical faculty in 1856. In 1877 he resigned these appointments to accept the professorship of chemistry and toxicology in Jefferson medical college, which he then retained till 1884, when he was made professor emeritus. During the civil war he served as acting assistant surgeon, in 1862-'3, at the West Philadelphia military hospital. Professor Rogers was appointed in 1872 by the United States treasury department one of a commission to examine the melters' and refiners' department of the United States mint in Philadelphia. He visited the mint in San Francisco in 1873, and in 1874 the assay-office in New York, and subsequently until 1879 he was frequently engaged on government commissions for the various mints, making valuable reports, in addition to which he served on the annual assay commissions in 1874--'9. From 1872 until his death he was one of the chemists that were employed by the gas-trust of Philadelphia to make analyses and daily photometric tests of the gas. The degree of LL. D. was conferred on him by Dickinson in 1877. He was a fellow of the College of physicians and surgeons, member of various scientific societies, one of the incorporators of the National academy of sciences, and president of the Franklin institute in 1875-'9. Besides various articles in the transactions of the societies of which he was a member, and in scientific journals, he was associated with his brother James (q. u.) in editing "Elements of Chemistry" (Philadelphia, 1846), and edited Charles (3. Lehman's "Physiological Chemistry" (2 vols., 1855). See "The Brothers Rogers," by William S. W. Ruschenberger (Philadelphia, 1885).