<p><strong>This 115-year-old picture of fingers is one of the first images ever made with <a href="http://www.britannica.com/EBchecked/topic/650351/X-ray">x-rays</a>, whose discovery is being feted Monday with an anniversary <a href="http://www.google.com/doodle4google/history.html">Google doodle</a>. (See <a href="http://news.nationalgeographic.com/news/2010/101108-x-rays-google-doodle-115th-anniversary-years-science-logo/">"X-Rays on Google: Surprising Ways the Rays Are Used Today."</a>) </strong></p><p>The hand belonged to Anna Bertha, wife of German physicist Wilhelm Röntgen, the discover of x-rays. The black glob on the fourth finger is a ring made of gold, which absorbs x-rays.</p><p>Röntgen stumbled across x-rays on November 8, 1895, while experimenting with an early vacuum tube known as a Crooke's radiometer. He noticed that, when the cathode rays from the tube struck the end of a discharge tube, a previously unknown type of radiation that could penetrate matter was emitted.</p><p>Röntgen created the picture of his wife's hand using the unknown, or <em>x,</em> rays a few days later.</p><p>"She apparently was not impressed by his photography," said Martin Richardson, a professor of optics at the University of Central Florida, whose group has been helping to pioneer the use of x-ray microscopy for biological studies since the early 1990s.</p><p>According to some accounts, Anna exclaimed "I have seen my death!" after seeing the now famous image.</p><p>(Related: <a href="http://news.nationalgeographic.com/news/2007/06/070607-iceman-murder.html">"Iceman Bled Out From Arrow Wound, X-Rays Reveal."</a>)</p><p>—<em>Ker Than</em></p>