Sir James Dewar (1842-1923), the Scottish chemist. In 1875 he obtained a professorial position at Cambridge and, two years later, at the Royal Institution in London. He invented the Dewar flask (known domestically as the thermos flask) and used it for the storage of liquified gases in his research on low temperatures. Dewar was the first to succeed in liquefying and then solidifying hydrogen. He also worked on specific heat capacities, electrical effects at very low temperatures, metal carbonyls, diffusion, high vacua, coal tar bases, dissociation of molecules at high temperatures, emmission and absorption spectra, soap films and the Sun's temperature.