exports and diverted most to production of ammonium picrate. Britain also blockaded supplies from Germany. Edison responded by undertaking production of phenol at his Silver Lake facility using processes developed by his chemists. He built two plants with a capacity of six tons of phenol per day. Production began the first week of September, one month after hostilities began in Europe. He built two plants to produce raw material benzene at Johnstown, Pennsylvania, and Bessemer, Alabama, replacing supplies previously from Germany. Edison also manufactured aniline dyes, which previously had been supplied by the German dye trust. Other wartime products include xylene, p-phenylenediamine, shellac, and pyrax. Wartime shortages made these ventures profitable. In 1915, his production capacity was fully committed by midyear. Phenol was a critical material because two derivatives were in high growth phases. Bakelite, the original thermoset plastic, had been invented in 1909. Aspirin, too was a phenol derivative. Invented in 1899, it had become a block buster drug. Bayer had acquired a plant to manufacture in the US in Rensselaer, New York, but struggled to find phenol to keep their plant running during the war. Edison was able to oblige. Bayer relied on Chemische Fabrik von Heyden, in Piscataway, New Jersey, to convert phenol to salicylic acid, which they converted to aspirin. (See Great Phenol plot.) It is said that German companies bought up supplies of phenol to block production of ammonium picrate. Edison preferred not to sell phenol for military uses. He sold his surplus to Bayer, who had it converted to salicylic acid by Heyden, some of which was exported. Spirit Phone In 1920, Edison spoke to American Magazine, saying that he had been working on a device for some time to see if it was possible to communicate with the dead. Edison said the device would work on scientific principles not by an occult means. The announcement caused a press heyday, though the actual nature of this invention remained a mystery, as there were no details for some time. In 2015, Philippe Baudouin, a French journalist, found a copy of Edison's Diary in a thrift store with a chapter not found in the previously published editions. The new chapter details Edison's theories of the afterlife and the scientific basis by which communication with the dead might be achieved. Final years and death Final years Henry Ford, the automobile magnate, later lived a few hundred feet