History of X-rays

In the latter half of the year 1895, a German scientist called Roentgen was working in his laboratory at the Physical Institute of the University of Wurzburg, Germany, experimenting with a type of discharge tube called Crooke's tube. The tube displayed a fluorescent glow when a high voltage current was passed through it. When he shielded the tube with heavy black cardboard, he found that a greenish fluorescent light could be seen on a fluorescent screen kept some 9 feet away. Roentgen concluded that a new type of ray was emitted from the tube that could pass through the black covering. The rays could pass through most substances, including the soft tissues of the body, but left the bones and most metals visible. One of his earliest photographic plates from his experiments was that of a film of his wife, Bertha's hand with a ring. Roentgen named the invisible radiations as X-rays (or unknown rays).