From that period forward, he devoted his time and talents to the business of his profession, to the improvement of medical science, and the melioration of the ills that flesh is heir to.
In 1789, he was elected professor of the theory and practice of physic, as the successor of Dr. Morgan, and in 1791 he was appointed to the professorship of the institutes of medicine and clinical practice, and upon the resignation of Dr. Kuhn, in 1806, he was honoured by the united professorships of the theory and practice of physic and of clinical medicine, which stations he ably filled until death closed his useful career.
Besides those already mentioned he performed many duties in various associations formed for benevolent purposes. He was president of the American Society for the Abolition of Slavery, vice president of the Philadelphia Bible Society, president of the Philadelphia Medical Society, one of the vice presidents of the American Philosophical Society, and a member of several other philanthropic institutions both in this country and in Europe. For many years he was one of the physicians of the Pennsylvania Hospital, and took a deep interest in its prosperity and welfare. Wherever he could be useful by counsel, influence, or action, he was sure to be found. To soothe the troubled bosom heaving with anguish, to alleviate the suffering patient writhing under pain, to supply the pinching wants of the poor and needy sinking under adversity, afforded Dr. Rush more pleasure than to have been placed on the loftiest pinnacle of political fame; a richer joy than to have been the triumphant chieftain of a conquered world.
Amidst his multifarious duties he arranged his time with so much system and order as to produce a routine of harmonious action. His professional duties, his books, and his pen, were all attended to in proper time. He wrote numerous literary, moral, and philosophical essays, and several volumes on medical science, among which were his “Medical Inquiries and Observations,” and a “History of the Yellow Fever.” He spent much time in the investigation of that fatal disease, and in endeavouring to arrive at the best mode of treatment. In this, as well as in many other cases, the lancet was his anchor of hope. During the prevalence of any disease his exertions to alleviate distress and arrest its progress, were unremitting and indefatigable. He obeyed the calls of the poor and needy as promptly as those of the rich and affluent. He was particularly attentive to those who had employed him when prosperity cheered their onward course, and were subsequently prostrated by adversity. He was not a sunshine friend.