 According to his 1902 FRS application citation he proved that "dry carbon and phosphorus will not inflame when heated in dry oxygen; that dry ammonia and hydrogen chloride when mixed do not unite, and that dry ammonium chloride and calomel respectively vaporise without dissociation... [and that] dry hydrogen and oxygen mixed together are not ignited by exposure to the temperature of melting silver".During WWI Baker was appointed scientific adviser to the War Office.He worked with his father-in-law in the development of specially resistant glass for the contact ‘horns’ of submarine mines.