James Dewar
James Dewar (1842-1923), Scottish chemist and physicist. He became a professor at Cambridge University in 1875 and at the Royal Institution, London, in 1877. His researches into low-temperature phenomena enabled him to produce liquid hydrogen and oxygen and solid hydrogen. The liquefied gases were stored in vacuum flasks, which Dewar invented, using the absorbent qualities of charcoal to create the necessary vacuum.