This folder contains correspondence and other documents relating to Edison's search for an inexpensive supply of cobalt ore for possible use in his alkaline storage battery. Included is correspondence with Albert W. Johnston of the American Nickel Works, Frank E. Stoneman of the North American Lead Co., and former Edison associate Francis Jehl. There are also letters from field workers R. D. Casterline and John Morris, who collected sample ores from around the United States. Related material can be found in the records of the Mining Exploration Company of New Jersey in the Company Records Series.

Approximately 20 percent of the documents have been selected. Among the items not selected are numerous field reports from Casterline and Morris; information collected regarding cobalt, cobalt suppliers, and possible deposits in Mexico and the United States; and documents that duplicate information in selected material.