Ether, Cathode Rays, and Electrons

William Crookes was one of the most enigmatic scientists of the nineteenth century. His pioneering work on spectroscopy led to the discovery of new elements and his cathodeCathode rayCathode rays tube was a forerunner of several modern electronic devices. Yet, he actively participated in psychic research with charlatans and strongly believed in a psychic force that could be transmitted through space by the living and the dead. While working with Crookes cathodeCathode rayCathode rays tube, Wilhelm Röntgen identified highly penetrating emissions that could pass through solid objects and produce an image on a photographic plate. There was immediate worldwide interest in the medical applications of Röntgen’s X-rays. JJ Thomson used Crooke’s tube to study the effects of cathodeCathode raysCathode rays on gases and was able to measure the charge-to-mass ratio of the negatively charged corpusclesCorpuscles in cathodeCathode raysCathode rays. The corpusclesCorpuscles (later called electrons) were several orders of magnitude smaller than a hydrogen atom. The discovery of the electron marked the beginning of the subatomic world of modern physics.