years' residence in Paris, at the School of Mines, where he became the associate of Prof. Alexandre Brongniart, the Abbé Haüy, and other distinguished men then prominent as professors in the schools of that great scientific metropolis. There he formed an intimate acquaintance with the late Prof. Keating, of Philadelphia, who in the same walks was drinking from the same fountain of knowledge. Being graduated in 1819, after a short tour through some districts of France, investigating the rock formations, collecting specimens, etc., he returned to this country and his native city, "charged with all the improvements of recent chemical discoveries, and the advancement in all its kindred arts," But he preferred the more abstract pursuit of his studies to the application of his knowledge to the practical arts.
Almost immediately after his return home, he was invited by President Cooper, of Columbia College, in South Carolina, to take the chair of Chemistry and Mineralogy in that institution. Becoming a member of the president's family, a warm friendship was formed between him and each member thereof, which ended only with their lives.
In 1826 he retired from the college and devoted his attention exclusively to geology as a profession. During that year he published in the newspapers and in Robert Mill's Statistics of South Carolina reports on the geology of the State, of which he made a survey or assisted in making one, having previously made one of North Carolina. "He also made quite a collection of minerals and rocks of the State, which were deposited in the University of South Carolina."
He then visited Mexico to examine gold-mining property, of which he had been solicited to take charge. His inspection soon convinced him that no profitable results could accrue to the owners, and he advised that it be abandoned.
In 1827-'28 he studied the geological features of the States of New York, Ohio, Kentucky, Tennessee, and Virginia, under the auspices of the State of New York, and made his report to its Legislature.
It was either at this time or immediately after his return from France that he spent much time in geological investigations in the vicinity of Philadelphia in company with Dr. Isaac Lea, who was his chosen and most intimate friend and associate from his early days to the end of his life. Subsequently Dr. Lea honored him by naming after him a class of fresh-water shells which he had been the first to discover and make known. It is from Dr. Isaac Lea's record of him that much of the information in connection with science, contained in the first part of this sketch, is derived. He also made at times extensive and careful investigations in the franklinite districts and marl beds of New Jersey.
