Background Information

Wilhelm Conrad Roentgen was appointed professor of physics at the University of Wuerzburg on October 1, 1888. Roentgen, who was 44 years old at that time.
In the late evening of Friday, November 8, 1895, Roentgen was working alone in his darkened laboratory with a Hittorf valve in a black box which was closely covered.
During these experiments, he observed that a few crystals of barium platinocyanide, which accidentally lay on the table , gave off a fluorescent glow. Roentgen examined this observation, deducing that the fluorescence could only have been caused by a hithert o unknown radiation stemming from the Hittorf valve.
Without divulging this information to anybody, he thoroughly examined, during the following eight weeks, the specific nature of this radiation. During this time, he took his meals in the laboratory; he even had his bed placed there. He discovered that th is radiation could penetrate solid substances and that it has the same effect on a photographic plate as light.
The first "Roentgen exposures" that were made were of metal objekts locked in a wooden case, and of the skeleton of his wife's hand.