264 POPULAR SCIENCE MONTHLY. 



Washington Medical College being offered to him, he 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 ac- 

 complished : " 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 audi- 

 ence. The theme was named, which being instantly taken up and 

 amplified upon, the ease and fullness with which he spoke re- 

 lieved 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 Vir- 

 ginia. 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 Gen- 

 eral 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 pub- 

 lished in 1846. He also conducted quiz classes of medical stu- 



