LEA, Thomas Gibson, botanist, born in Wilmington, Delaware, 14 December, 1785; died in Waynesville, Ohio. 25 September, 1844. He was of Quaker descent, and his ancestors were among those who accompanied William Penn to this country. He was occupied with business pursuits until 1827, when he withdrew from all mercantile occupations and devoted himself to botany. He was an industrious collector, and left at his death an extensive herbarium with the synonyms and description of many new species, and an unfinished catalogue. There was published posthumously from his papers, by William S. Sullivan, a "Catalogue of Plants, Native and Naturalized, collected in the Vicinity of Cincinnati, Ohio" (Philadelphia, 1849). --His brother, Isaac, naturalist, born in Wilmington, Delaware, 4 March, 1792; died in Philadelphia, Pennsylvania, 8 December, 1886, showed in early youth great fondness for natural history. This was fostered by his mother, who was familiar with botany, and was developed by his association with Lardner Vanuxem, who encouraged his interest in mineralogy and geology. His birthright in the Society of Friends was forfeited by his joining a company that was raised for the defence of the United States in 1814, although the organization was never called into service. In 1815 he was elected a member of the Academy of natural sciences in Philadelphia, and soon afterward published an account of the minerals that he had observed in the vicinity of Philadelphia. This was his first paper, and appeared in the "Journal of the Academy." he became in 1821 a member of the publishing firm of Mathew Carry, whose daughter he had married, and continued as snell until 1851. Meanwhile his leisure was devoted to science, and in 1825 he began a series of memoirs on new forms of fresh-water and land shells, which he maintained throughout his life. The genus Unio received his special attention, and in 1827 he published his first paper on it, afterward issuing a synopsis of this genus (1836; 4th ed., 1870). The separate papers collected under the title of "Observations on the Genus Unio" (Philadelphia, 1827-'74) form thirteen quarto volumes magnificently illustrated. His "Contributions to Geology" (1835) was the best illustrated paleontological work that had appeared in the United States. In his "Fossil Footmarks in the Red Sandstones of Pottsville" (1852) he described his discovery of the saurian footprints in the sandstone 700 feet below the conglomerate of the coal formation. This discovery was of great interest, for the existence of an air breathing animal as low as the coal measures had not at that time been definitely accepted. Subsequently the first bones and teeth ever found in this stratum in the United States were described by him, and he named the animal clepsysaurus Pennsylvanicus. The number of new forms, recent and fossil, that were made known by him amount to nearly 2,000. These descriptions he communicated to the Academy of natural sciences in Philadelphia. His collection of fresh-water shells, marine and land shells, minerals, fossils, and geological specimens were bequeathed to the National museum in Washington, on condition that a room be devoted exclusively to them and the whole called the "Isaac Lea Collection." Mr. Lea received the degree of LL.D. from Harvard in 1852, and was a member of many scientific societies in the United States and Europe. He was elected president of the Philadelphia academy of natural sciences in 1858, and of the American association for the advancement of science in 1860. His papers include 279 titles, and a complete bibliography of them, illustrated by an etched portrait, was published as a "Bulletin of United States National Museum, No. 23" (Washington, 1885).--Isaac's son, Mathew Carey, chemist, born in Philadelphia, Pennsylvania, 18 August, 1823, received his education at home, and then turned his attention to chemistry, which he studied under James C. Booth. His early researches were numerous, and the titles of nearly fifty papers are credited to him by the younger Silliman in his "American Contributions to Chemistry" (Philadelphia, 1875). Mr. Lea has become best known through his large contributions to the literature of photographic chemistry. He has made a specialty of the chemical effects of light, especially on the haloid salts of silver, on which subject he has published numerous papers in the. "British Journal of Photography" and in home journals. He is the author of a "Manual of Photography" (Philadelphia, 1868; 2d ed., 1871), which is recognized as a work of standard authority among photographers.--Another son, Henry Charles, publisher, born in Philadelphia, Pennsylvania, 19 September, 1825, was educated in Philadelphia, and at the age of seventeen entered the publishing house of his father, ultimately becoming principal of the concern. Several papers on chemistry and conchology, notably "Description of New Species of Shells," were published by him. During the civil war he organized the system of municipal bounties to encourage volunteering, and also wrote much for the periodicals. Since 1857 he has devoted special attention to European mediveval history, and has published "Superstition and Force: Essays on the Wager of Battle, the Wager of Law, the Ordeal and Torture" (Philadelphia, 1866); "Studies in Church History: the Rise of the Temporal Power, Benefit of Clergy, Excommunication, the Earn Church and Slavery" (1869); "An Historical Sketch of Sacerdotal Celibacy" (1867); and "A History of the Inquisition of the Middle Ages" (3 vols., New York, 1888).