Used with
permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA,
http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps
Michael Faraday's (1791-1867) interests in electricity and magnetism were wide and varied. Observing the alignment of iron filings around a bar magnet, he decided that they followed lines of force of a magnetic field. He induced a current in one of two wire coils wrapped around a metal ring by passing a current through the other coil, creating a transformer. His ideas about force fields were later expressed mathematically by Maxwell as Maxwell's equations. As a chemist Faraday liquified carbon dioxide and chlorine and discovered benzene.