1845-1923

German physicist who discovered x rays in 1895. Although other scientists had probably unknowingly observed x rays previously, Röntgen was the first to notice that the glass wall of his cathode-ray tube was emitting rays. He discovered the penetrating properties of x rays and took a number of photographs, including one of his wife's hand, showing for the first time the living skeleton. News of his discovery spread rapidly, and x rays were soon put to use in medicine, metallurgy, and physics. See long biography on p. 369.