A Pillar of the Royal Institution
The Collected Papers- of Sir James Dewar. Two vols. (Cambridge University Press. Sis.) -
AT the top of Albemarle Street stands a building handsomely fronted with Corinthian pillars, in which the architecturally
learned will recognize an imitation of the Temple of Antoninus at Rome. This is the Royal Institution, which, if such an expression is ever justified, may well be called a temple of
science. The twin demi-gods indissolubly associated with it, Davy and Faraday, are among the few EngliSh men of science of whose fame and achievements the average educated man knows something. 'Tyndall, for long years the Professor of Natural Philosophy of the Institution, on his retirement in 1887 handed over the handsome apartments at the top of the building to a comparatively young man, of forty-five years of age,, who had already for ten years been the Professor of Chemistry. This man, James Dewar, who was -knighted in 1904, speedily identified himself with the Institution, and for thirty-six years he and Lady Dewar made their home there a centre of graceful hospitality appreciated equally by men of science and by those enlightened amateurs who support the Royal Institution. The Institution was ever near his heart : he feared for its fate during the dark days of the War and, recalling the difficulties through which it passed after the Napoleonic wars, was not without forebodings for its future after the newer European struggle. The two volumes of his Collected Papers now published are Dewar's best memorial, but the present flourishing state of the Royal Institution under Sir William Bragg, who has worked wonders, would probably gratify him even more.
Dewar is best known to the rank and file of scientific workers by the great body of work which he carried out on the liquefac- tion of gases. He was the first in this country to produce liquid air in any quantity, and to demonstrate its sensational properties. He was, in a sense, not actually the first man to prepare liquid hydrogen, for the Polish experimenter, Wro- blewski, had seen a momentary froth of it in his attempts to liquefy the gas, but Dewar was definitely the first to collect hydrogen in the liquid state, and already in 1899 he was preparing it by the pint. In the following year he solidified it. The degree of cold with which he was dealing in such experiments May. be best. conveyed by pointing out that the temperature of the melting of solid hydrogen is only fourteen degrees centigrade above the absolute zero of temperature, anything below which is scientifically inconceivable. The liquefaction and solidification of hydrogen was a particularly. important service to science, since, quite apart from providing us with a new step on the downward path to absolute zero, it definitely disproved the pretty conjecture, based on the chemical behaviour of hydrogen, that hydrogen in solid form
might have metallic properties. . In the course of his researches on liquefying gases Dewar was led to invent the vacuum-jacketed flask, for preserving the contents from the passage of heat. - The device is familiar to everyone under the name of " Thermos flask." Dewar never patented or protected his invention ; had he done so it would probably hive brought him a fortune.
The liquefaction of gases, and the various researches on the properties of bodies at low temperatures which the free supply of liquid air and liquid hydrogen enabled Dewar to
carry out, are far from constituting Dewar's life work, as a glance at the Collected Papers' is sufficient. to demonstrate. The beautiful coloured plate which adorns Volume II. recalls his researches on soap films, those• tenuous membranes which
charm layman and philosopher alike, and, having been made to reveal so much, still remain mysterious. Dewar worked out% technique, described in his papers, by which soap bubbles could be made to endure—how long may be judged from the fact that a bubble blOwn by him lived in a bottle at the Institution for eighteen months, and then broke only on being moved. He showed that soap films could be used as detectors of sound and demonstrators of liquid motions. This was his last work : his early work was on difficult problems of organic chemistry, and on the physiological action of light. Them are two hundred and fifty odd papers reprinted in the volumes before us, and even then all the spectroscopic work which Dewar carried out in collaboration with Liveing is omitted; for it was published in a separate volume a few years ago. Neither is there any mention of the part which •DeWar played in the invention of cordite, for the work was never published.
His services during the Great War are recalled by the paper " Liquid Oxygen in Warfare," which describes how at his hands liquid oxygen was used to supply, breathing air to aeroplane pilots at high altitudes, and also how large metal Vacuum vessels for liquid air can be made. It will interest Men of science to know that the volumes include two papers con- taining hitherto unpublished material, one on Calorimetry with Liquid Gases, and the other on Molecular Specific Heats at Low Temperatures, compiled from the notes of Mr. W. J. Green, his trusted assistant.
Neither by inclination nor training was Dewar an academic scientist. He founded no school, attracted no body of young researchers such as Sir William Bragg has gathered round him. In nearly all his researches the general plan of campaign was simple enough, and success was largely a matter of experience; resource and extraordinary manipulative technique, so that he hadto depend entirely upon his own skill and the services of specially trained assistants. He did not, as a University Professor is bound to do, have ready a large number of minor problems which could be carried out under his direction by inexperienced men, or, rather, perhaps, the direction of such men would not have suited with his character. These things are matters of temperament. In many ways he recalls the virtuosi who made the early -days of the Royal Society so memorable a time for English science. In those days men such as Robert Boyle and Robert Hooke did not restrict themselves to a narrow range of problems or a particular technique, but were ready to adventure upon any problem whose solution seemed of philosophic interest. To be chemist; physicist, and physiologist is rather more difficult in our days than it was then, and it is well for English science that she can still produce such men, who combine versatility with authority, and, with a kind of masterly amateurism, are ready to undertake any subject with a certain touch, and an assur- ance of obtaining valuable results. E. N. DA C. ANDRADE.
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