In 1803 Lewis had instructions from President Jefferson that required him to visit five members of the American Philosophical Society. He had already spent several weeks being tutored at Andrew Ellicott's home in Lancaster. Lewis's first objective was to continue his instruction in celestial observation with Robert Patterson at the building to which the University of Pennsylvania had moved just the year before. It too had been called the President's House in prospect that Philadelphia would become the permanent national capital, but Washington and Adams, who might have occupied it, chose not to do so.
"House intended for the President, in Ninth Street"
Begun by the Commonwealth of Pennsylvania in 1792 as a gift to the nation's first President, the mansion was still under construction during Washington's two terms, and his successor, John Adams, declined the honor. When Lewis reached Philadelphia in 1803 to begin preparations for the expedition, the mansion was occupied by the University of Pennsylvania, and it was here that he may have consulted with mathematician Robert Patterson. In the background are the Alms House and House of Employment.
Benjamin Rush and Caspar Wistar lived within a block of each other, Benjamin Smith Barton only a few blocks farther at Fifth Street, north of High (Market) Street. This proximity, and the fact that the three men were members of the same medical faculty, neither ensured nor required friendship. Rush and Barton had not been on speaking terms for at least ten years. The relationship between Wistar and Rush had cooled when Wistar, recovered from yellow fever in 1793, had rejected Rush's therapies of purging and bleeding—as had many of Rush's colleagues in the College of Physicians. There followed bitter disputes about whether the disease was imported or domestic, contagious or non-contagious, all in the absence of knowledge of cause. It was an age in which the words "microbe" and "asepsis" were unknown, let alone part of theory or practice.
Jefferson's letters to Patterson and Ellicott explicitly asked that they instruct Lewis. On the other hand, the three physicians were simply to identify "those objects" to which it was "most desireable" that Lewis turn his attention. Only Rush admitted supplying medical advice. He might have considered that he had after all provided it to Jefferson personally, despite Jefferson's known and perhaps selective skepticism regarding medical practice of the time.
Lewis's letters provide little comment on his interviews with the physicians. It is not clear how much time he spent with each of them, how widely their conversation ranged, or what further communication Jefferson might have conveyed in oral instructions to Lewis.1
1. For instance, the latest news about efforts to buy the Louisiana Territory, a matter significantly affecting the circumstances under which the Expedition would be approaching native peoples. Lewis did reveal the effort being made in a letter to Clark.
Funded in part by a grant from the National Park Service, Challenge Cost Share Program