These tributes were read at the American Philosophical Society on the centenary of Wistar's death. Included are tributes by Isaac M. Hays, "Caspar Wistar as a Citizen and Philosopher," and George A. Piersol, "Dr. Caspar Wistar as a Human Anatomist."

Accompanying this reprint from A.P.S. "Proceedings" 37(1898):88-107, are facsimilies of the Jefferson draft of the Declaration of Independence; 3 original letters from Richard Henry Lee, Jr., to John Vaughan, 1836 and 1840; an original letter from Isaac Lea to Vaughan, 1840; a note on the manuscript by Vaughan; and two original letters between Vaughan and George Combe, 1841.

This collection 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).

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).

The Calendar of the Papers of Benjamin Franklin prepared by Isaac Minis Hays for the bicentennial of Franklin's birth in 1906 provides access to the largest portion of the Franklin Papers at the APS. The items were originally bound into volumes in roughly chronological order, with letters to Franklin preceding those from Franklin and at the end of the collection, Franklin's letters owned by the University of Pennsylvania. Each manuscript is still identified by Hays' reference numbers, which include a roman numeral refering to the original volume followed by an arabic number to identify the folio. The electronic version of the finding aid replicates Hays' calendar, including the introductory material and item-level descriptions. It has been updated to reflect corrections in the metadata, corrections of personal names, dates, and description.