Nikola Tesla film in his laboratory in previous experiments (later identified as ""Roentgen rays"" or "X-Rays"). His early experiments were with Crookes tubes, a cold cathode electrical discharge tube. Tesla may have inadvertently captured an X-ray image—predating, by a few weeks, Wilhelm Röntgen's December 1895 announcement of the discovery of X-rays when he tried to photograph Mark Twain illuminated by a Geissler tube, an earlier type of gas discharge tube. The only thing captured in the image was the metal locking screw on the camera lens. In March 1896, after hearing of Wilhelm Röntgen's discovery of X-ray and X-ray imaging (radiography), Tesla
Ludwig Wilhelm Sachs "Geheimen Medizinalrat" (private medical advisor). Ludwig Wilhelm Sachs Ludwig Wilhelm Sachs (29 December 1787 in Groß-Glogau – 17 June 1848 in Königsberg) was a German physician. From 1807 studied medicine at the universities of Königsberg, Berlin and Göttingen, receiving his doctorate at the latter institution with the dissertation-thesis ""De Humorum corporis animalis vi vitali"" (1812). He later served as a physician in war-time hospitals in Königsberg, and in 1816 obtained his habilitation. In 1818 he became an associate professor at Königsberg, followed by a full professorship in 1826. In 1832 he was named director of the medical clinic, then in