The Caspar Wistar Papers are now digitized and available to view in the APS Digital Library. The entirety of the collection is presented in a bound volume titled Letters to Caspar Wistar. Caspar Wistar (1761-1818, APS 1787) was a physician and paleontologist from Philadelphia. Along with serving on the faculty of the University of Pennsylvania, Wistar also served in a variety of roles at the American Philosophical Society, including Curator and Vice President of the Society. In 1815 Wistar would also go on to succeed Thomas Jefferson as President of the Society.
The bound volume, which contains over 40 letters, mainly consists of correspondence sent to Wistar. Most of the letters reflect his wide range of interests within the sciences, such as distillation, fossils and skeletons, and scientific expeditions. For example, the volume includes a 1793 letter from the American Philosophical to André Michaux, written by Jefferson, in which directions are laid out for exploring along the Missouri, then westward toward the Pacific Ocean. Also of note are several letters from German naturalist Wilhelm Gottlieb Tilesius von Tilenau, in which Tilesius discusses natural history, skeletons, and Siberian mammoths.
Wistar’s correspondence also touches upon the discovery of elk in Virginia, a description of a new invention for distilling fresh water from salt, as well as a discussion about the flora of Egypt. Correspondents include Thomas Jefferson, André Michaux, and Hugh Williamson. The letters in this bound volume present a glimpse into the scientific world of the late 18th and early 19th centuries written by some of the most important scientific figures of the time.