Greetings from iainthepict. This blog of mine is meant to be like a 'Book of Days' or a kind of 'Scottish Year Book' if you will. The idea was to present an event for each day of the year. Somewhere in here, you can find out what happened, affecting Scotland and the Scots, on any given day of the year. Your comments and observations are very welcome.
The photograph is by Sam Perkins (check him out on Facebook at Sam Perkins Photography) and was taken near Oban.

Tuesday, 27 March 2012

Sir James Dewar

Sir James Dewar, chemist and physicist, died on the 27th of March, 1923.

When he was but a laddie, James Dewar built himself a violin, but that’s not what he’s famous for. Dewar never became a famous violin maker or luthier in the mould of a Stradivarius. However, Dewar became equally famous in his own field, physics, having turned his attention to more practical and pragmatic things. What Dewar is arguably most famous for, in Scotland and amongst chemists anyway, is the Dewar flask. Many Scots households would have owned a Dewar flask, known outside Scotland as a Thermos or vacuum flask. Dewar invented the Dewar flask in 1892, to aid him in his research work; primarily so that he could store liquified gases at extremely low temperatures.

Dewar's invention of the vacuum flask was not manufactured for commercial or home use until
1904, when two German glass blowers from Munich obtained the patent for the flask. Somehow, Dewar lost an ensuing court case against the thieves from Thermos. Incidentally, the Germans came up with the name after holding a contest to rename the Dewar flask and a resident of Munich offered 'Thermos', which came from the Greek word ‘therme’ meaning hot. In 1907, Thermos GmbH sold its trademark rights to three independent companies: The American Thermos Bottle Company of Brooklyn, NY; Thermos Limited of Tottenham, England; and Canadian Thermos Bottle Co. Ltd. of Montreal, Canada. Nevertheless, Scots steadfastly refuse to call it anything other than a Dewar flask.

Apart from his eponymous flask, Dewar is well known for his work on the properties of matter at very low temperatures (approaching absolute zero) and the liquefaction of gases. That science is what you’d call cryogenics today. Dewar was also the first person to liquefy hydrogen and was the scientist who first came up with a way to produce liquid oxygen in large quantities, although some credit must be given to the Frenchman, Louis Cailletet, whose initial success, in 1877, helped in Dewar's method. Dewar was also particularly interested in atomic and molecular spectroscopy as he worked in those fields for more than twenty-five years.

During a long and successful career, Dewar was nominated several times for the Nobel Prize, but never won the coveted award. Despite being the first to liquefy hydrogen and producing a means of doing the same to oxygen, Dewar didn't  win the race to liquefy helium. That latter achievement was made by the Dutchman, Heike Kamerlingh Onnes, of the University of Leiden, in 1908, for which work the Belgian received the Nobel Prize. So helium was more of an achievement or what?

When Dewar turned his attention to hydrogen, which at the tail end of the 19th Century could not be liquefied at the low temperatures then obtainable, his problem was getting down to the temperatures needed. Using what was called the Joule-Thomson effect, together with improvements made by a Bavarian called Karl Paul Gottfried von Linde, Dewar eventually produced a machine that enabled him to reach temperatures as low as 14 degrees Kelvin. His breakthrough came in 1898, when Dewar became the first person to liquefy hydrogen. The following year, Dewar also became the first scientist to produce solid hydrogen.

Despite not being Nobelled, the list of Dewar’s major achievements is quite impressive. Sir James Dewar developed structural formulas for benzene (1867); studied the specific heat of hydrogen; became the first person to produce hydrogen in liquid form (1898); was the first to solidify hydrogen (1899); constructed a machine for producing liquid oxygen in quantity (1891); invented the Dewar flask (1892); co-invented cordite, a smokeless gunpowder, with Sir Frederick Abel (1889); and discovered that cooled charcoal can be used to help create high vacuums (1905), which later proved useful in atomic physics.

Sir James Dewar was born in Kincardine-on-Forth on the 20th of September, 1842. Jamie was the son of an innkeeper (or a wine merchant, depending on which biography you read) and the youngest of six boys. When he was ten, Dewar suffered a serious case of rheumatic fever, which lasted for two years. As the biographies will tell you, “showing his future prodigious nature” during that period of illness, he built himself a violin. And yes, he could play the thing – why bother otherwise, eh!  Music remained a lifelong interest of Dewar's.

In 1858, after leaving Dollar Academy, James Dewar entered the University of Edinburgh to study physics and chemistry, where he was a pupil of Lyon Playfair. Whilst there, James developed a mechanical model of Alexander Crum Brown's graphic notation for organic compounds. That model was sent to the German, August Friedrich Kekulé von Stradonitz, who invited Dewar to spend some time in his laboratory in Ghent as a result, which was nice.

Dewar undoubtedly had a very successful career. In 1869, he was appointed lecturer in chemistry at the Royal Veterinary College, Edinburgh, and from 1873, he also held the post of assistant chemist to the Highland and Agricultural Society of Scotland. Dewar was appointed Jacksonian Professor of Philosophy at the University of Cambridge in 1873, and four years later he was appointed Fullerian Professor of Chemistry at the Royal Institution in London. Dewar was also responsible for one of the most important developments in the history of the Royal Institution. That was the establishment and endowment of the Davy-Faraday Research Laboratory, of which he became Director.

Whilst at Cambridge, Dewar collaborated with George Downing Liveing on an extensive spectroscopic study to do with atomic and molecular states. That led to a very public disagreement with Norman Lockyer about the dissociation of matter. That spat is illustrative of one of Dewar's chief characteristics. Apart from his scientific achievements, he was also a great arguer. As Robert John Strutt, the fourth Lord Rayleigh, once wrote, arguing with Dewar, “was akin to being a fly in molasses.”

James Dewar was knighted in 1904 and died Sir James Dewar in London on the 27th of March, 1923. Dewar's funeral service was held in the Director's flat at the Royal Institution in London.

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