N-03-12-18: "Rob. Rafn Dec 18 1903" [notes entitled "Substances tried for Radioactivity"; only a loose note from Edison to Rafn has been selected]

[The following note covers all of the notebooks in Group 8: Miscellaneous Experiments.]

The thirty-four notebooks in this group primarily cover the period July 1900-July 1911, but several contain entries from as late as 1914. They were used by Edison employees, including Arthur H. Glaister, Walter E. Holland, and Ludwig F. Ott, and contain only occasional notations or drawings by Edison. The entries pertain to a variety of subjects. Included is a book by Cloyd M. Chapman providing details of his work on a dry placer process for gold ore concentration and several books by other authors on radioactivity. Also included are notes on tests of primary batteries; experimental notes pertaining to lamps, mining, metals, the "Edison effect," electroplating, oil filtering, and ore separation; and a few entries regarding photography and motion pictures. In addition to the entries by Chapman, Glaister, Holland, and Ott, there are notes by Alvin D. Caskey, George Hetherington, John F. Ott, and others. Two of the books, N- Undated.38 and N-06-11-21, contain rough drawings by Edison that appear to be unrelated to the contents of the books themselves; N-03-12-18 contains a loose note from Edison to Robert Rafn.