Shortly after the death of Faraday in 1867, three biographies of him--each admirable in its own line--were published. The “Life and Letters of Faraday,” by Dr. Bence Jones, secretary of the Royal Institution, which was issued in 1868 in two volumes, has long been out of print. “Faraday as a Discoverer,” written in 1868 by Professor Tyndall, which, though slighter as a record...