This notebook was used during December 1904 and May-June 1905. Most of the book contains notes by Edison and an unidentified experimenter regarding storage batteries. The experiments are numbered from 1 through 645. Among the entries are items pertaining to the loss of capacity, including an examination of the presence of mercury in the electrolytic solution. Other entries relate to the rejuvenation of the nickel electrode. At the end of the book is a phonograph drawing from June 1905. The pages are unnumbered. Approximately 140 pages have been used.