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
Multiple discovery pre-existing concepts and facts. This is what is meant when one says that a scientist or artist has been "influenced by" another—etymologically, that a concept of the latter's has "flowed into" the mind of the former. Not every new concept so formed will be viable: adapting social Darwinist Herbert Spencer's phrase, only the fittest concepts survive. Multiple independent discovery and invention, like discovery and invention generally, have been fostered by the evolution of means of communication: roads, vehicles, sailing vessels, writing, printing, institutions of education, reliable postal services, telegraphy, and mass media, including the internet. Gutenberg's invention of printing (which