Radiograph of a hand with a ring, 1895.

Photograph of a radiograph of a hand, covered with glass, taken by Roentgen, Wurzburg, Germany. The X-ray or 'new' photography caused a sensation when it was discovered by German scientist Professor Wilhelm Conrad Roentgen (1845-1923) in 1895. In 1895, as Professor of Physics at the University of Wurzburg, Roentgen was experimenting with a Crookes' radiometer (cathode ray tubes), invented in 1875. He noticed that when cathode rays struck the end of a discharge tube, rays of a new kind were emitted, capable of penetrating matter. Roentgen was awarded the first Nobel Prize for physics in 1901.