French physicist <a href="https://en.wikipedia.org/wiki/Augustin-Jean_Fresnel" id="mwRA" rel="mw:WikiLink" title="Augustin-Jean Fresnel">Augustin-Jean Fresnel</a>, in a "note" read to the <a href="https://en.wikipedia.org/wiki/French_Academy_of_Sciences" id="mwRQ" rel="mw:WikiLink" title="French Academy of Sciences">Academy of Sciences</a>,<!-- signed 8 September, read 16 September --> reports a direct refraction experiment verifying <a href="https://en.wikipedia.org/wiki/David_Brewster" id="mwRg" rel="mw:WikiLink" title="David Brewster">David Brewster</a>'s hypothesis that <a href="https://en.wikipedia.org/wiki/Photoelasticity" id="mwRw" rel="mw:WikiLink" title="Photoelasticity">photoelasticity</a> (as it is now known) is stress-induced <a href="https://en.wikipedia.org/wiki/Birefringence" id="mwSA" rel="mw:WikiLink" title="Birefringence">birefringence</a>.<sup about="#mwt25" class="mw-ref reference" data-mw='{"name":"ref","attrs":{"name":"fresnel-1822s"},"body":{"id":"mw-reference-text-cite_note-fresnel-1822s-2"}}' id="cite_ref-fresnel-1822s_2-0" rel="dc:references" typeof="mw:Extension/ref"><a href="./September_16#cite_note-fresnel-1822s-2" id="mwSQ" style="counter-reset: mw-Ref 2;"><span class="mw-reflink-text" id="mwSg">[2]</span></a></sup>