Canadian-born physician and researcher (1849–1919) who was a founding professor of Johns Hopkins Hospital. ALS signed “Wm. Osler,” one page, 4 x 6, personal letterhead, postmarked March 25, 1897. Letter to a fellow doctor. In full: “Wilson is coming in tomorrow at 7 p. m. to dine with me—will you not join us? Do not dress—come as you are.” In fine condition. Accompanied by the original mailing envelope, addressed by Osler to “Dr. Green, Marine Hospital Service, Custom House, city.” RR Auction COA.