In the mid-to late-1800s, the world was experiencing a scientific revolution. Phenomena that had never before been truly understood, such as light, heat, and radiation, were systematically unravelled, and by such great scientists as Henri Becquerel, Marie Curie and Thomas Young. Among these phenomena was the nature of electricity: how it worked, and why. The early experiments to solve the riddle of electricity often included the use of anode-cathode tubes--glass tubes containing an anode at one end and a cathode at the other. When most of the air was evacuated from this tube, an electrical charge could be observed jumping across the gap between the two electrodes. one scientist who performed such an experiment was Michael Faraday; he noticed that, as the amount of air within the tube decreased, a faint glow could be detected between the anode and the cathode. However, the...