Michael Faraday, as we have seen, by researches of consummate ability laid the foundation of modern electrical science and art. In that field there is to-day no inventor more illustrious than Professor Alexander Graham Bell, the creator of the telephone, that simplest and most important of electrical devices.[34] Not content with obliging a wire to carry speech in electric waves, Professor Bell has impressed beams of light into the same service. The successive steps by which he arrived at the photophone are of extraordinary interest. His story as given in the proceedings of the American Association for the Advancement of Science, 1880, is here somewhat condensed:-- [34] Professor Bell’s narrative of how he invented the telephone is given in “Invention and Discovery,” one of the six volumes of “Little Masterpieces of Science,” Doubleday, Page & Co., New York. In “Flame, Electricity and the Camera” by the present writer, published by the same firm, is a chapter describing the telephone in its later developments. This chapter was revised by the late Professor Alexander Melville Bell, father of the inventor. “In bringing before you some discoveries by Mr. Sumner Tainter and myself, which have resulted in the production and reproduction of sound by means of light, let me sketch the state of knowledge which formed the starting point of our experiments. I shall first describe selenium, and the uses of it devised by previous experimenters; our researches have so widened the class of substances sensitive, like selenium, to light-vibrations that this sensitiveness seems to be a property of all matter. We have found this property in gold, silver, platinum, iron, steel, brass, copper, zinc, lead, antimony, german-silver, ivory, celluloid, gutta percha, hard and soft rubber, paper, parchment, wood, mica, and silvered glass. At first carbon and microscope glass seemed insensitive; later experiments proved them to be no exceptions to the rule.