Selenium Cells, by Thomas W. Benson 61574 [Subtitle: The Construction, Care and Use of Selenium Cells with Special Reference to the Fritts Cell] [Link: http://www.gutenberg.org/6/1/5/7/61574 ] [Files: 61574-0.txt; 61574-h.htm] Thanks to Paul Marshall and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) David