Founded in 1936, the Oskar Diethelm Library houses, preserves, and provides access to printed books and serials, archives and manuscripts, photographs, prints, sound and video recordings, and other ephemera and is part of Weill Cornell Medical College's DeWitt Wallace Institute of Psychiatry: History, Policy, & the Arts. The library's rare book collection contains approximately 35,000 titles dating back to the 15th century dealing with psychiatry, psychology, psychoanalysis, mesmerism, spiritualism, phrenology, witchcraft, and related topics. World-renowned individuals and organizations are also represented in the approximately 1500 linear feet of archives, including Donald W. Winnicott, Thomas Salmon, and the American Psychoanalytic Association.