Wilhelm Conrad Roentgen, German physicist, c 1900.
© Science Museum / Science & Society Picture Library
One of a stereo pair of photographs taken by Roentgen. On 8 November 1895, Roentgen (1845-1923) discovered what came to be known as 'x-rays'. He noticed that when a current was pased though a Crookes tube covered with a piece of black card, a nearby piece of paper painted with barium cyanide fluoresced. Later, he found that these x-rays pased through flesh, enabling the bones to be clearly seen. In 1901, he was the first recipient of the Nobel Prize for Physics.