This collection contains correspondence, reports, notes, and notebooks. Clarke's participation in various organizations is documented, including the American Philosophical Society, American Chemical Society, American Otological Society, and the American Society of Biological Chemists. His chemistry research is detailed in thirteen notebooks, 1903-1971 (the 1903 volume is on photographic chemistry and processes). There is also one volume on the clarinet, for Clarke was an expert clarinetist. The personal and family correspondence is principally with Mrs. Dorothy Clarke Middleton and Mrs. Agnes Helfreich Clarke.

Working on bacterial viruses in 1945, Seymour S. Cohen offered the first systematic exploration of the biochemistry of virus-infected cells and of how viruses multiply. His subsequent research included delineating the phenomenon of thymineless death, developing derivatives of ara-A compound, working on RNA synthesis, studying the effects of polyamines on metabolic systems, and studying plant viruses (including viral cations). Much of his research has contributed to the chemical treatment of cancer and viral infections.