Roentgen's X-ray photograph, 1895.
© Science Museum / Science & Society Picture Library
X-ray photograph taken by Wilhem Conrad Roentgen (1845- 1923), of his wife's hand in December 1895 (some sources give the date as 22 December 1895). Roentgen was Profesor of Physics at the University of Wurzburg, and it was in 1895 that he experimented with cathode rays and made the discovery which he named X-rays: the 'X' signifying their unknown origin. The property which made X-rays so interesting was their ability to pas through matter. As a result it became posible for the first time to make visible images of the bones inside the body. This is the oldest surviving X-ray image of a part of the human body.