Letter to Harvey Cushing from Minis Hays, American Philosophical Society, 104 South 5th Street, Philadelphia, Pennsylvania, USA. Hays does not believe that Osler attended the International Congress of Medicine at Philadelphia in 1876. He suggests that Cushing consult the original registration manuscript kept in the Library of the College of Physicians in Philadelphia.

Letter to Harvey Cushing from Thomas McCrae, 1627, Spruce Street, Philadelphia, Pennsylvania, USA. McCrae draws Cushing's attention to the animal parasite, "Sphyranura Osleri," named after Osler. This was written about in the Journal of Morphology, Vol. I, No. I, September 1887.

Letter to Harvey Cushing from Thomas McCrae, 1627, Spruce Street, Philadelphia, Pennsylvania, USA. McCrae corrects Cushing's information regarding Osler's Ingersoll Lecture on Science and Immortality in 1904.

Letter to Harvey Cushing from Thomas McCrae, 1627, Spruce Street, Philadelphia, Pennsylvania, USA. McCrae has gathered a number of letters from Osler, which he now sends to Cushing.

Letter to Harvey Cushing from Henry H. Donaldson, Wistar Institute of Anatomy and Biology, Philadelphia, Pennsylvania, USA. Donaldson responds to Cushing's request for information regarding Osler's involvement with the Anthropometric Society.

Letter to Harvey Cushing from Henry H. Donaldson, Wistar Institute of Anatomy and Biology, Philadelphia, Pennsylvania, USA. Donaldson informs Cushing that the President of the Anthropometric Society is F.X. Dercum. The chief object of the society was the preservation of the brains of its members; Osler's name did not appear among the list of members. However, Donaldson does recall seeing Osler at a meeting of the Society at the Art Club in Philadelphia in 1890. Donaldson will send a copy of Osler's "Leaven of Science," which he delivered at the opening of the Wistar Institute.