Michael Faraday (1791-1867) discovers that light propagation in a material can be influenced by external magnetic fields
Citation:
Editors. "Discovery that light propagation is influenced by external magnetic fields".
The Literary Encyclopedia. First published 01 May 2009
[http://www.litencyc.com/php/stopics.php?rec=true&UID=6294, accessed 18 May 2013.]