After leaving Harvard, he travelled westward, and lectured on physiological subjects--the comparative anatomical and physical conformation of the cranium of the Caucasian and negro races,--besides giving class lectures. These he rendered successful. While his arguments on these subjects were in strict conformity to acknowledged scientific principles, they are also marked by his peculiar and original theories. For instance, he argues on this subject that the pigment which makes the complexion of the African black is essentially the same in properties as that which makes the ruddy complexion of the European, the African’s being concentrated rouge, which is black. This he urges by illustrations considered scientifically true. He maintains that these truths will yet be acknowledged by writers on physiology. On his return to Pittsburg, after the completion of his lecturing tour, he entered upon the duties of a physician, for which his native benevolence and scientific ardor eminently qualified him. Here he was known as a successful practitioner. His skilful treatment of the cholera, which prevailed to some extent in Pittsburg in 1854, is still remembered. It is worthy of interest, in view of the pro-slavery spirit which brooded over every locality, to record that while there, on the occasion of the establishment of a municipal and private charity, he was selected, with other physicians, as one of the sub-committee of advisers and referees to whom applications were made by white and colored persons to enjoy its provisions. This demonstration of courtesy on the part of the municipal authorities of Pittsburg towards one of its citizens belonging to an unpopular race was certainly an evidence of liberality hardly to be expected at that time. He still took part in all movements relative to the advancement of his people. He held in most of these a prominent position; his long experience and life devotion to the cause of progress insured him this always. He published a call for a national emigration convention, and, it finding favor, there assembled at Cleveland, Ohio, August, 1854, many of the eminent colored men of the northern and western states, to discuss the question of emigration. At best, emigration found but little encouragement among the people of the free states, and could hardly be called popular at the South. Knowing the aversion held by the colored people of the country to colonization in any form, it was a matter of surprise to note the course taken by this convention. An importance was attached to this movement, so unprecedented as to constitute it a remarkable feature in their political history.