Alexander Graham Bell in 1876 invented the speaking telephone, and Edison and Elisha Gray in the United States followed almost immediately with other telephonic inventions for electrically transmitting speech.
To-day, by reason of other uses to which electricity is applied, electrically deposited copper of high conductivity is in everincreasing demand, and commands a higher price than copper refined by fusion.
91, p. 1938) among the gaseous products formed when a platinum wire is electrically heated under the surface of acetic anhydride.
Guntz (Comptes rendus, 1901, 133, p. 872) electrolyses a saturated solution of barium chloride using a mercury cathode and obtains a 3% barium amalgam; this amalgam is transferred to an iron boat in a wide porcelain tube and the tube slowly heated electrically, a good yield of pure barium being obtained at about looo C. The metal when freshly cut possesses a silver white lustre, is a little harder than lead, and is extremely easily oxidized on exposure; it is soluble in liquid ammonia, and readily attacks both water and alcohol.
The electrical phenomena show that there are two ions to the molecule, and that these ions are electrically charged.