This collection contains individual letters or small groups of letters from the correspondence of scientists, physicians, and other health practitioners. Provenences vary greatly. Some were donated by collectors or descendents of the recipient, others purchased, and others removed from books in the Historical Library in which collectors had placed them. Most letters were acquired in the period before 1960. Members of the Beaumont Medical Club collected and donated letters related to Connecticut medicine. John F. Fulton, in particular, purchased individual letters from book stores and book sellers for the collection. A number of the letters in the collection are to and from Yale School of Medicine faculty members. There are also some letters by Yale medical students and alumni. Of particular note in this collection are letters on inoculation and vaccination for smallpox, and on anesthesia.