One block of glass, one of aluminium, two of calcite and two of quartz, viewed under x-ray. Photoprint from radiograph by W.K. Röntgen, 1895.

The print is from one of the first radiographs (x-ray photographs) made by the German physicist, Wilhelm Konrad Röntgen (1845-1923). Röntgen discovered the electro-magnetic rays he named "x-rays" (also known as "Röntgen rays") in Würzburg in November 1895. Röntgen mailed this and other prints to, among others, the British physicist Sir Arthur Schuster, along with an offprint of his article "Über eine neue Art von Strahlen" (1895). Dr Nora H. Schuster, Sir Arthur's daughter, presented the prints to the Wellcome Institute Library in 1962