https://creativecommons.org/publicdomain/zero/1.0/https://www.rawpixel.com/image/13976032
W. C. Roentgen, professor of physics at Giessen, Wuerzburg and Munich, discoverer of X-rays. Reproduction of etching by J. Lindner-Mohn, 1900.
Original public domain image from Wellcome Collection
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