Correspondence; manuscripts, including drafts of his autobiography; reprints of his writings; subject files relating to his research and to work during World War I, and to professional activities; laboratory notebooks, his own and those of his students; clippings; photographs; and certificates of election or appointment to scientific societies.

Also included: two boxes of correspondence and papers of his son, Hermann, mainly letters of condolence on the death of his father, and laboratory notebooks of some of his students.