Hand of an eight year old girl, 1896.
© National Media Museum / Science & Society Picture Library
Photogravure taken from the original X-ray. In 1895, as Profesor of Physics at the University of Wurzburg, Wilhelm Conrad Roentgen (1845-1923) 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. On 22 December 1895 he took the first X-ray, an image of the ringed hand of his wife Bertha. He was awarded the first Nobel Prize for physics in 1901.