Röntgen's X-Rays

A new kind of radiation passes through flesh

First published: W. C. Röntgen, "Ueber eine neue Art von Strahlen", *Sitzungsberichte der Würzburger Physik.-medic. Gesellschaft* (1895).

A barium platinocyanide screen glows on the far side of a covered cathode-ray tube. Invisible rays pass through cardboard, wood, and (with the famous photo of his wife's hand) flesh.

In November 1895 Röntgen noticed that a barium platinocyanide screen near a covered cathode-ray tube glowed when the tube was operating, even with the screen sealed from light. He had discovered penetrating radiation (X-rays), capable of passing through opaque materials but absorbed differentially by tissue and bone. The first famous X-ray image, of his wife Anna's hand showing the bones and her wedding ring, captivated the world. The discovery — recognised by the first Nobel Prize in Physics in 1901 — opened medical diagnostics, atomic structure studies (X-ray diffraction → crystallography → DNA structure), and the modern era of penetrating-radiation physics.