Sir James DewarArticle Free Pass Sir James Dewar, (born Sept.
20, 1842, Kincardine-on-Forth, Scot.—died March 27, 1923,
London, Eng.), British chemist and physicist whose study of low-
temperature phenomena entailed the use of a double-walled vacuum
flask of his own design which has been named for him. Educated
at the University of Edinburgh, Dewar became a professor at the
University of Cambridge (1875) and at the Royal Institution of
Great Britain, London (1877), holding both posts throughout his
life. Dewar developed structural formulas for benzene (1867),
did research in spectroscopy for more than 25 years, and by 1891
had constructed a machine for producing liquid oxygen in
quantity. About 1892 he conceived the idea of using vacuum-
jacketed vessels for the storage of low-temperature liquid
gases, and the resulting device proved so efficient in
preventing the influx of external heat that it became an
essential tool in low-temperature scientific work. The principle
of the Dewar flask has also been used exte