James Dewar was born in 1842 in England. His scot parents had moved from Scotland and settled down in England few years before his birth. After his primary and, secondary education he entered St Mary’s Medical College in London. He started practising as a doctor after passing out.
As there were no thermos flasks those days people were unable to keep drinks like cocoa, tea and coffee warm even for a short time after preparation. Doctor Dewar’s small son refused drinking cold milk and this posed the doctor a considerable problem.
In order to overcome the problem doctor Dewar began a series of experiments and after a time he succeeded in producing the vacuum flask.
What he really did was making a bottle both with an outer wall and an inner wall and a vacuum space between the two. When hot liquids such as milk, water, tea or coffee was poured into the inner bottle the liquid remained hot for few hours. That was because the heat could not escape through the vacuous space. The new invention kept the son’s milk warm enough and the doctor was happy and satisfied.
Later, many others made numerous improvements on Doctor Dewar’s flask so that it may keep the contents hot or cold for longer periods.
Doctor Dewar built a device that could produce liquid oxygen also. In his later years James Dewar joined the academic staff of the University of Cambridge. He passed away in the year of 1923 in Cambridge, England.
