Radiation Fundamentals

In 1895, Wilhelm Conrad Roentgen, a German physicist, accidentally discov- ered that he could see the bones of his hand when he held it in front of a high voltage cathode ray (Crooke's) tube.  As the electricity passed from the Crooke's tube through objects, a fluo- rescent glow was cast on a piece of cardboard painted with barium platino- cynide.  Roentgen called this mysteri- ous ray "x-ray" named for the math symbol "x" or unknown quantity.

X-rays became a valuable diagnostic tool for medical science.