Pioneers/Discovery of X-Radiation in Dentistry In 1895, Professor Wilhelm C. Roentgen, a German physicist, was working with a cathode ray tube, very similar to our fluorescent light bulb . The tube consisted of positive and negative electrodes encapsulated in a glass casing. On November 8, 1895, Roentgen was conducting experiments in his laboratory on the effects of cathode rays. He evacuated all the air from the tube and passed a high electrical voltage through it after filling it with a special gas. When he did, the tube began to emit a fluorescent light. Roentgen then shielded the tube with heavy black paper and found that a green fluorescent light could be seen coming from a screen located a few meters away from the tube. It had produced an unknown beam emitted from the tube that could pass through paper. He discovered that this new ray would pass through most objects, casting shadows of solid substances. He first investigated with his hand and was surprised when he saw his bones. His discovery would open up an exciting field for doctors because it was now possible to study...