834- THE POPULAR SCIENCE MONTHLY. 



years' residence in Paris, at the School of Mines, where he became 

 the associate of Prof. Alexandre Brongniart, the Abbd Haiiy, 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 Philadel- 

 phia, 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, col- 

 lecting specimens, etc., he returned to this country and his native 

 city, " charged with all the improvements of recent chemical dis- 

 coveries, and the advancement in all its kindred arts," But he 

 preferred the more abstract pursuit of his studies to the applica- 

 tion 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. Be- 

 coming 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 pub- 

 lished 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 con- 

 nection with science, contained in the first part of this sketch, is 

 derived. He also made at times extensive and careful investiga- 

 tions in the franklinite districts and marl beds of New Jersey. 



