These logbooks record two voyages (to Corunna, Spain, 1789-1790, and to Oporto, Portugal, 1791, and returns to Philadelphia), with observations of differences in temperature between air and water, especially when passing the Gulf Stream or any land or banks.

This volume was made at Wilmington, Delaware, for determining the longitude, from 1 July-14 October. It records the position of selected stars and planets. Contains also: Note regarding his astronomical clock, and entries relative to his work in continuing the Mason & Dixon's line.

This volume contains medical notes by Wistar, including observations on yellow fever and arguments to prove its foreign origin, facts relative to the progress of the fever in 1797, the infection and death of Colonel Van Emburgh, the infection of the crew of the ship "Deborah" and of the Durham boat (1802), an account of the diseases which afflicted the family of James Hammar in Montgomery County (Pa.), facts relating to the typhus fever of 1812-1813, case histories (1796-1803), temperature chart (1758-1759, 1760), and a thermometrical journal (1760-1765) kept by Charles Norris and copied by Wistar from notes in possession of Joseph Parker Norris.