<a href="https://en.wikipedia.org/wiki/Harald_Hirschsprung" class="extiw" title="en:Harald Hirschsprung">Harald Hirschsprung</a>, for whom <a href="https://en.wikipedia.org/wiki/Hirschsprung%27s_disease" class="extiw" title="en:Hirschsprung's disease">Hirschsprung's disease</a> is named
Jens and Charles Bendix Petersen. The caption on the photo says (in Danish) "Royal Court Photographer".
between 1860 and 1916 <div style="display: none;">date QS:P,+1500-00-00T00:00:00Z/6,P1319,+1860-00-00T00:00:00Z/9,P1326,+1916-00-00T00:00:00Z/9</div>
The <a rel="nofollow" class="external text" href="http://www.kb.dk/images/billed/2010/okt/billeder/object457223/da/">Royal Danish Library</a>. I losslessly cropped the image from their website with the command <tt>jpegtran -crop 1150x1680+224+80</tt> to remove copyrighted elements.