Washington Medical College being offered to him, lie hesitated to accept it, thinking he was not sufficiently ready of speech for a lecturer. He finally undertook the work, and, although it was not remunerative, it served to discover the fact that he shared the gift of eloquence which distinguished his brothers. The ice being thus broken, he found it easy to give chemical lectures before the Mechanics' Institute, in Baltimore, and later he lectured also on physics.
Dr. Joseph Carson states in his memoir of Dr. Rogers that it was William B. Rogers who induced his brother to venture upon the career of a college lecturer, and thus relates how it was accomplished: "To convince him that he had nothing to apprehend on that score [lack of fluency], his brother William prevailed upon him to accompany him to the lecture room, and there, placing the future professor behind the desk, constituted himself the audience. The theme was named, which being instantly taken up and amplified upon, the ease and fullness with which he spoke relieved him of his diffidence and apprehension. This was his first effort to lecture, and, like this, all his future performances were without notes or facilities of recollection, except those incident to the arrangement of the topic."
In September, 1830, being then twenty-eight years of age, he married Rachel Smith, of Baltimore, a birthright member of the Society of Friends.
Cincinnati was the residence of Dr. J. B. Rogers from 1835 to 1839, this period being the whole term of existence of the Medical Department of Cincinnati College, in which he had accepted the professorship of Chemistry. . The summer vacations of these four years he spent as an assistant to his brother William in fieldwork and chemical investigations on the Geological Survey of Virginia. While in Cincinnati he declined the office of melter and refiner in the branch mint at New Orleans, offered to him by the President of the United States.
Dr. Rogers now, 1840, removed to Philadelphia and became an assistant to his brother Henry, who was the State Geologist of Pennsylvania. He also turned his knowledge of chemistry to account in various other occupations. He was appointed in 1841 lecturer on chemistry in the Philadelphia Medical Institute, then a flourishing summer school, which had been founded by Dr. Nathaniel Chapman. From 1844 to 1847 he was Professor of General Chemistry in the Franklin Institute, of which institution he had become a member when he went to live in Philadelphia. In this period he and his brother Robert compiled a text-book on Chemistry from the Inorganic Chemistry of Dr. Edward Turner and the Organic Chemistry of Dr. William Gregory. It was published in 1846. He also conducted quiz classes of medical stu-