Professor James Dewar (1842-1923) FRS, was a Scottish chemist and physicist.
1842 September 20th. Born
He is probably best-known today for his invention of the Dewar flask, which he used in conjunction with extensive research into the liquefaction of gases. He was also particularly interested in atomic and molecular spectroscopy, working in these fields for more than 25 years.
1923 Died on 27th March 1923.
1923 Obituary 
"The scientific world is very much the poorer by the death of Sir James Dewar, which took place early in the morning of Tuesday of this week. Sir James was not, strictly speaking, an engineer, but his life's work marched o nearly hand in hand with engineering that our profession must mourn his loss almost equally with that of the chemist, with which his career was more particularly identified. One is accustomed to associate with the Royal Institution of Great Britain the idea of progress, and Dewar, as occupying the position of Fullerian Professor of Chemistry in that historic building, ably upheld its traditions in that respect. All the world knows of his researches into the phenomena witnessed, and the behaviour of materials, at extremely low temperatures, and it will probably be in connection with his discoveries in that direction that his name will most prominently go down to posterity. His invention of the vacuum flask, now known universally as the Thermos flask , was really incidental to his other discoveries in the domain of cold, but it has proved of very considerable value to the world at large, seeing that by its means hot liquids can be kept hot, and cold liquids cold, almost indefinitely. What he sought to discover and what he did discover was a vessel in which he might store for reasonable periods without serious loss such bodies as liquid air. But he must evidently have realised what a boon his invention must confer on mankind in general, and, seeking not emolument for himself, he proclaimed his discovery to the world. He did not, we believe, make a penny piece out of it. Then, too, his researches made feasible the commercial isolation of gases in a manner impossible before, and revealed many secrets which otherwise would have remained long hidden. Nor must it be forgotten that to him, in collaboration with the late Sir Frederick Abel, is due the discovery of the smokeless "powder" used by the British Army and Navy - cordite. We make no attempt at giving a life history of this most distinguished Scotsman - he was born in Kincardine-on-Forth in the year 1842- but add our lament to that of scientist the world over that he was not spared for many years longer to carry on the beneficent work which has been of such good service to humanity at large."
1923 Obituary 
SIR JAMES DEWAR, M.A., F.R.S., was born at Kincardine-on-Forth on the 20th September, 1842.
After being educated at Dollar Academy he went to Edinburgh University, where he was a pupil of, and later became assistant to, Lord Playfair, who was at that time Professor of Chemistry.
In 1875 he was appointed Jacksonian Professor of Natural Experimental Philosophy at Cambridge. Two years later, in 1877, he became Fullerian Professor of Chemistry at the Royal Institution and retained that position until his death, which occurred on the 27th March, 1923.
His important researches on the liquefaction of gases and the properties of matter at temperatures approaching absolute zero were carried out at that Institution. By 1886 he had produced oxygen in the solid state, and by 1891 he was making liquid air in large quantities. In the following year he invented the vacuum container in which liquid air could be stored.
In 1898 he succeeded in liquefying hydrogen, and in the following year obtained this gas in the solid state. He also attacked the problem of the liquefaction of helium, but was prevented by ill-health from carrying out his purpose.
In addition to investigating the physical constants of the liquefied gases, he also conducted researches on the electrical resistance and thermo-electric, magnetic and dielectric constants of various substances at low temperatures.
In much of this work he acted in conjunction with Prof. J. A. Fleming. His research on the properties of radium at low temperatures also added much to our knowledge on the subject of radioactivity. In other branches of science his researches include the physiological effect of light, spectroscopic investigations, the diffusion of gases, and the properties of thin liquid films, while in 1888, as a member of the Explosives Committee, he invented, in conjunction with Sir Frederick Abel, the smokeless powder known as cordite.
He was elected a Fellow of the Royal Society in 1877, and a Member of the Institution of Electrical Engineers in 1881. In 1904 he received the honour of Knighthood.