This folder contains correspondence and other documents relating to the technical and commercial development of Edison's technologies for ore separation and concentration, as well as to other ore concentration processes. Among the items for 1919 is a letter about a purported business venture in Wyoming involving Edison and Buffalo Bill Cody. Also included is correspondence with William O. Manson about the possibility of building an electric plant to refine platinum ore. In addition, there are inquiries about the defunct Edison Ore Milling Co., Ltd., and Edison's crushing roll and magnetic ore separation technologies. The correspondents include the Marble Cliff Quarries Co. of Columbus, Ohio, and the National Tin Corp. of Hill City, South Dakota.

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