A screen glowing across the room revealed a new kind of ray

In 1895, Wilhelm Röntgen noticed a screen glowing across his lab even though his cathode-ray tube was covered in black cardboard. He'd found a new kind of ray that passed through flesh but not bone, and used it to photograph his wife's hand, bones and wedding ring visible. She reportedly said, 'I have seen my death.'

— Wilhelm Conrad Röntgen, Über eine neue Art von Strahlen (On a New Kind of Rays) — Sitzungsberichte der Würzburger Physikalisch-Medizinischen Gesellschaft, 1895