The talkies (1930)

12 THE TALKIES the boundaries between what were then largelyconsidered separate sciences, and began to show that no branch of science could be considered without its relationship to others. Before the discovery of the light-sensitive properties of selenium there had only been the faintest suspicion that there could be any connection whatever between the activities of light, chemistry, and electricity, although the connection between light and chemistry was of course known to the early pioneers of the art of photography. The fact that selenium, and, indeed, a number of other substances, wTould alter their resistance to the passage of an electric current under various degrees of illumination, was a discovery of the most momentous importance. It came about in this way : There was in charge of the Transatlantic Cable Station at Valencia a certain Mr. May, an assistant of Professor Willoughby Smith ; May noticed one day that the needles of his indicators were flickering in a manner that was quite unexplainable. He made a series of tests to see if anything were wrong or if an endeavour were being made to pass a message to him ; but he was quite unable to account for these spasmodic and irregular move