The Samuel Theobald Collection spans much of his medical career and consists primarily of professional correspondence. The correspondence (1871-1918) includes exchanges with surgical instrument manufacturers, medical societies, colleagues abroad, and noted American ophthalmologists Adolf Alt, Clarence Blake, Swan Burnett, Isaac Hays, and Henry D. Noyes. The correspondence with his peers includes mixed reviews regarding several controversial papers of Theobald's, such as his advocacy of the use of large probes in the treatment of strictures of the nasal duct, and the use of boracic acid in the treatment of eye diseases. The collection also includes patterns for "Theobalds Eye Bandages", with pen and ink figures illustrating their use. In addition, there are notes regarding the diameters of probes and the results of probing canals (c.1878), as well as lecture notes and notes regarding pharmaceutical mixtures. There is a 1925 prohibition permit for prescribing intoxicating liquor for medicinal purposes. Two pages of notes written by his great-grandfather Nathan Smith, of Yale College, describe eye operations performed in 1811 on Massachusetts Governor Levi Lincoln and on a 16-year-old girl. The Theobald papers also include Annual Reports (1876-1883) of the Baltimore Charity Eye and Ear Hospital & Dispensary and a small collection of photographs (10 images) of patients and medical specimens. There is one folder of letters (1850-1869) to W. White Cooper, which Cooper gave to Theobald. (Correspondents include B.C. Brodie, William Jenner, and Richard Owens.) Also included is an account book of payments to household servants (1882-1890).