These documents cover the years 1847 to 1953, the year of Millikan's death, but the core of the collection consists of the official papers generated by Millikan after his move to Pasadena in 1921. The collection includes more than 125,000 pages of letters, notebooks, unpublished speeches, addresses, lecture notes, and family papers.

This collection is primarily correspondence and also notes on experiments concerning the cytology research of Lewis and his wife, Dr. Margaret Reed Lewis, at Johns Hopkins University, Carnegie Institution of Washington, and finally at the Wistar Institute of Anatomy and Biology in Philadelphia. There is significant material relating to his professional society activity in the American Association of Anatomists (President, 1934-1936) and the International Society for Experimental Cytology.

An electrical engineer, inventor, and entrepreneur, Elihu Thomson was an innovator in electrification in both a technical and corporate sense. With interests that ranged from the technical (electrical meters, high-pressure steam engines, dynamos, generators) to scientific (fused quartz optics, X-rays), Thomson acquired over 700 patents in his career, and in 1882, founded one of the early electrical corporations in the United States, the Thomson-Houston Company, which merged with the Edison Electric Company in 1892 to form the General Electric Company. The Thomson Papers are a massive and nearly comprehensive collection documenting the wide range of Thomson's scientific and technical interestsm from his electrical experiments, inventions, and patents, to his interests in astronomy, geology, and medicine, as well as his role in the development of two major corporations involved in electrification, the Thomson-Houston Electric Company and General Electric Company. Roughly three quarters of the collection is dated between 1890 and 1920 when Thomson was associated with General Electric, and was active in professional groups such as the American Institute of Electrical Engineers (AIEE), International Electrotechnical Commission. His research interests. The balance of the collection is comprised of eight boxes and five volumes relating to Thomson's patents; a series of notebooks kept at Central High School; 43 letterbooks, 1882-1936; diaries of trips to Europe; notebooks on genealogy; scrapbooks of cards, photographs, clippings, and other souvenirs; and 2 vols. of tributes on his eightieth birthday, etc.

Mostly concerned with Blakeslee's studies on beans, blood groups, colchicine, Datura, embryo cultures, and horticulture. Many letters relate to the support and direction of the Smith College Genetics Experiment Station, which he headed. Other letters are about the Carnegie Institution of Washington, "Biological Abstracts," American Association for the Advancement of Science, American Philosophical Society, Institut de France, University of Connecticut. Also contains travel letters from Germany and miscellaneous lectures.

Leonard Carmichael was a psychologist whose most significant contributions were made in the fields of child psychology and biopsychology. Educated at Tufts and Harvard, he taught at Princeton, Brown, and Rochester, later returning to Tufts to serve as its President from 1938-1952. An outstanding administrator, Carmichael served as executive officer for the Smithsonian Institute from 1952-1964, and was subsequently vice president for research and exploration at the National Geographic Society. In his later years, he served as President of the American Philosophical Society from 1970-1973. This large and varied collection reflects the entire range of Carmichael's prolific career. It includes a variety of types of records, including correspondence, committee reports and records, long series of articles and speeches, drafts of papers and books, and pocket notebooks. All phases of his professional life are covered, from his years in academia, to his time at the Smithsonian Institute and the National Geographic Society, as well as his involvement in a large number of professional organizations.

After receiving his doctorate from Harvard in 1923, the physicist John Clarke Slater did postgraduate work at Cambridge University and on the continent working n quantum theory with both Niels Bohr and Werner Heisenberg. Slater was appointed to the head of the department of physics at MIT in 1930, which he and Karl Compton worked effectively to transform into one of international stature. His own work on the electromagnetic theory of microwaves was fundamental to the development of radar systems. During the Second World War, he was affiliated with the radiation laboratory and after he helped found the solid state and molecular theory group, the interdisciplinary Center for Materials Science and Engineering, the Research Laboratory of Electronics, and the Laboratory for Nuclear Science. After his retirement from MIT in 1966, Slater moved to the University of Florida, remaining active until his death in 1976. The Slater Papers contains a wealth of information on the development of physics at MIT, as well as Slater's post-1966 work at the University of Florida. There are about 133 (7 linear ft.) research notebooks, 1944-1976, and a long series (30 linear ft.) of folders, containing lectures, scientific notes, drafts of manuscripts and papers, correspondence during his collaboration with the Los Alamos Labs, 1966-1970, and extensive correspondence relating to the National Academy of Science. Information about American-Swedish exchange in quantum science is located in the correspondence with Per-Olov Löwdin.