X-rays have eluded mankind for a long time, since the only natural source of X-rays on earth stems from the decay of rare radioactive substances such as Uranium. The discovery of X-rays was an accident: On November 8, 1895 W.C. Röntgen (Ref: Figure 1), a professor at the University of Würzburg in Germany, had been experimenting with a cathode ray tube, similar in construction to a light bulb. After covering up the tube to shield the visible light emitted from it, he noticed that a fluorescent screen present in the room was glowing. He deduced correctly that he discovered a new, mysterious kind of radiation that was different from visible light. He worked feverishly for the next several weeks, mentioning his discovery to no one. Röntgen quickly realized that these rays could penetrate materials that are opaque to visible light and that photographic film could be used to detect their presence. Roentgen himself produced the first X-ray shadowgraphs of bones by simply placing an object in front of a sheet of photographic film and turning his cathode ray tube on.

On December 22 he took his wife to his laboratory, and made the famous photograph of the bones of her hand. (Ref: Figure 2) He wrote up his findings, calling the new radiation X-rays and submitted his remarkable paper for publication on December 28. He sent out a few preprints, and the news spread like wildfire. His results were confirmed in dozens of laboratories within days. He was invited to show his results to the Emperor, which he did on January 13 1896. The discovery was reported in the February issue of the Scientific American, and on March 1 X-rays were used to locate bullets in soldiers injured in a battle in Ethiopia. Over the same calendar year over 1000 articles were devoted to X-rays.

Figure 1: W.C. Röntgen.

Figure 2: One of the first X-ray shadowgraphs taken by Röntgen showing the bones of his wife's hand including the wedding ring.

The amazing power of X-rays to take internal images of the body to diagnose bone fractures and other medical conditions was quickly realized and the technology was spread quickly to hospitals and doctors. Röntgen received the first Nobel prize awarded.