The physician Charles Caldwell received his medical degree under Benjamin Rush at the University of Pennsylvania in 1796, but shared little, theoretically or stylistically with his mentor. After accepting a chair in medicine at Transylvania University in 1819, Caldwell became a champion of phrenology and racial polygenism, and he was an ardent opponent of the introduction of chemistry into the medical curriculum. In his master's thesis from the University of Pennsylvania, Richard A. Glock traces Caldwell's opposition to the introduciton of chemistry into medical education in the United States during the early decades of the 19th century, his idiosyncratic vitalistic physiology, and the relations between medical schools in the eastern and western states.

This volume includes several printed and manuscript items related to the death of Caspar Wistar, in January 1818.

The collection includes letters between Hutchinson and his uncle Israel Pemberton, written while Hutchinson was a student of medicine in London. There are also 12 tickets of admission to medical lectures in Philadelphia and London, including one given by William Hunter, and 3 unused cards of admission to Hutchinson's own lectures. Miscellaneous items include Hutchinson's marriage certificate; genealogical data on the Hutchinson, Hare, and Pemberton families; and stock certificates, 1857-1872, of the McKean and Elk Land and Improvement Company. Materials dated post-1793 are to and from Hutchinson family members.

These papers reflect Isaac Hays' interests and activities in the medical profession and as an editor. His interest in paleontology, especially in the controversy with G. W. Featherstonhaugh, is also represented. There is one separate volume (77 letters) containing correspondence about natural history and naturalists, written to Hays by C. L. Bonaparte, George Ord, Thomas Say, and Charles A. Lesueur. The correspondence in the larger collection, however, contains much material on the American Journal of the Medical Sciences, particularly illuminated in the correspondence with John D. Godman. The I. Minis Hays material consists of letters from doctors, relating to medicine and medical publications and editing, as well as medical organizations. Most significant of the correspondence is that with John Shaw Billings (ca. 60 letters).