The X rays were discovered by Wilhelm Conrad Roentgen
Roentgen got the help of his wife for the first Xray. Roentgen scanned his wife's hands and identified that the rays can pass through flesh and skin to showcase bones.
German scientist discovered X rays accidentally while working in the lab. The discovery turned the medical industry drastically.
Roentgen was experimenting with an electron discharge tube while the discovery took place.
First X ray
image source: https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=2ahUKEwjIlLGl-vnZAhUJkpQKHVDfBjoQjRx6BAgAEAU&url=https%3A%2F%2Fobservationdeck.io9.com%2Flets-learn-about-a-random-scientist-vol-2-wilhelm-con-1625515752%2F1625577436%2F%2Briamisra&psig=AOvVaw3IBAEdjxC8YYR39v4_vSK1&ust=1521602774815359