The correspondence is written chiefly from Priestley in America (1790-1802). The printed works include Priestley's "Syllabus of a Course of Lectures on the Study of History" (1765), John Aikin's "Heads of Chemistry" (1781), and a catalog of books belonging to the Warrington Academy (1775).

These letters are to Rev. Theophilus Lindsay and Rev. Thomas Belsham pertaining to natural history, science, and theology.

These letters, from the Wellcome Historical Medical Society's collections, are on a variety of topics, primarily natural history and medicine.

This collection includes correspondence to and from Boskovic; a travel journal in Europe; and a large number of manuscripts on astronomy, hydrography, hydro-mechanics, mathematics, geometry, mechanics, and optics; and a volume of poetry.

These letters of American Philosophical Society members and prominent early American scientists were selected from Carson's extra-illustrated draft of "A History of the Medical Department of the University of Pennsylvania" (Philadelphia, 1869).