IN the history of science there have been few more unexpected and few more fruitful discoveries than that made by Wilhelm Konrad Röntgen on November 8, 1895, and described not many days after in his paper "Über eine neue Art von Strahlen" read to the Physico-Medical Society of Würzburg. Copies of the paper reached England early in 1896, and Nature of January 23, 1896, contained a translation of it. By those fortunately in possession of the necessary apparatus, Röntgen's experiments were repeated with delight and wonder, and not only that, they were put to very good purpose. In Berlin, on January 20, 1896, a medical man had with the new methods detected a glass-splinter in a finger, and at Liverpool on February 7, Dr. C. T. Holland found by X-rays a bullet in a boy's hand. None had received news of the discovery with greater interest than Sir Arthur Schuster, who in his book "The Progress of Physics during Thirty-three Years", published in 1911, tells how his laboratory was inundated by medical men with their patients, among whom was a ballet dancer whose trouble had been diagnosed as bone disease but who all the time had a needle in her foot. In April he and his assistants were called to Nelson, Lancashire, to a woman who had been shot by her husband and whose head Schuster explored with the new rays. There was no opposition to the application of Röntgen's discovery, as there had been to those of Lister and Pasteur, and medical science and surgery have benefited universely from it. Even after two world wars, it may be that X-rays have saved more lives than bullets have destroyed.