A GREAT SCIENTIST.

Dominion, Volume 1, Issue 225, 16 June 1908, Page 10

A GREAT SCIENTIST.

■THE NEW CHANCELLOR OF CAMERIDCE. LORD RAYLEIGH'S CAREER. " In electing Lord Rayleigh to bo lier new Chancellor, in succession to the _Duke of Devonshire, Cambridge University confers tlio highest honour at her disposal upon ono of her most distinguished sons —certainly, now that Sir George Stokes and Lord Kelvin are no longer with us, her most distinguished living representative in the' field of physical science," says "The Times." Lord Rayleigh was the Senior Wrangler of his year, and, like the seventh Duke of Devonshire, first Smith's prizeman, and his success was followed in 1866 by election to a Fellowship at his college, Trinity, which, however; ho had to vacate in 1871 on bis marriage with a sister of Mr. 'Balfour. He began to contribute original papers to scientific periodicals in 1869, and soon made himself such a reputation that on Clerk Maxwell s premature death in 1878 lie was. chosen to succeed him as professor of experimental physics at Cambridge. ■He did not hold this position for very long—only fivo years—but in that time, in addition to much research,' lie applied himself to the reorganisation of tlio teaching and practical work in his department, ono result of his efforts being seen m the considerable increase in the number of men_ who entered for the Natural- Scienco fripos m 1884 as compared with 1879. SUCCESSOR TO TYNDALL. In 1887 lie was elccted professor of natural philosophy at the Royal Institution, in successiou to Tyndall, and thus the important experimental resources of the homo of • Farada y w ere put at his disposal, m ~ on 10se his private laboratory at Terlmg Place, his scat in Essex. This position he retained till 1905, when ha reached the highest honour to which a man of science can aspire in this country, the presidency of the Royal Society. The year hetore he had been awarded the Nobel Prizo tor physics, and, he was one of the select few admitted to the English Order of Merit instituted % king Edward at his Corona--tlOll.

To the ordinary mail Lord Rayleigh is probably best known as the discorcrer of tho inert gas argon, tho definite existence of which he announced, jointly with Sir William Ivatnsay, to the British Association at its 11 n Irt 6 ,' 11 1894 > although it'had in all likelihood been actually obtained bv . nry Cavendish more than a century previously. _ But this discovery, striking though c r' a V™ y , J noans . tlio most remarkable ot Lord Rayleigh s achievements, and is not even a very important part of tho foundations upon which his scientific reputation rests. Indeed, it he had never made it, liia tamo would not have been less than it is now. let. it affords an excellent illustration ot two characteristics which mark his scientuic work. . ■ THE ATMOSPHERE. Ono is his caution in taking nothing for granted, which has led on more than ono occasion to. his exorcising a disturbing inliuonco 111 connection with matters that have been supposed to bo perfectly well known and generally accepted as established facts.' t or many years chemists had been comfortably reposing in tho belief that they had fully ascertained the composition of the atmosphere, until he showed them that an-' other element, of which thev had .taken no •account, was present in it'to tho not inconsiderable extent of about one per cent. It was soon found,' too, that argon is associated with four, previously unrecognised companions, and thus its. discovery meant the addition of an entirely new ' and interesting group of gaseous substances to those already on the list of tho elements. In the place, the isolation of argon illustrates the extreme accuracy and careful-, ness of his. work. The existence of argon was dotected solely through exact weighing. Wishing to test the so-called law of Prout that tho atomic weights of. the other elements are exact 'multiples of that of ■hydrogen, Lord Rayleigh undertook a'long and laborious redetermination of the densities of the principal gaseous elements. When ho came to nitrogen ho found that a given volume of what was supposed to' bs the pure gas persistently woighed more when it had been extracted from tlio atmosphere than when it had been prepared by chemical moans from some compound which contained it. The difference was not great, .but it was greater than could be explained by any errors that were possible under the conditions in which the. experiments had been carried out; and finally it became evident; that one kind of nitrogen contained something, of different donsity, which was absent in the other. HOW HE ISOLATED ARGON.

This conclusion having been reached by Lord Rayleigh, tho next, step was to isolate the impurity which caused tho difference. This task was effected by removing the truo nitrogen, Lord Rayleigh submitting tho mixed gases with the addition of oxygen to tho action of the electric discharge over weak alkali, while Sir William Ramsay absorbed tho nitrogen by means of heated magnesium. The residue left by both motliods was argon. ' ■ In this research there was no room for tho application of mathematics; it was merely a matter of delicate manipulation and accurate measurement. ; But it is as a mathematical physicist that Lord Rayleigh excels; fo.r that reason his work must largely remain caviare to tho general public, and his eminence can be fully appreciated only byphysicists having a similar, equipment. Hia mathematical powers are of tho highest order; but they aro strictly his sorvant, novor his master, and there is an economy in their application which partially accounts for the refinement and elegance of expression noticcable in his mathematical treatment. , < DISTINGUISHED IN MANY FIELDS. Everywhere his results are checked by wido knov.-lcdgo and deep insight, and by consummate experimental skill. There is scarcely any branch of physics at which Iw has not worked. His treatise on sound at once attained tho position of a standard, and his articlo on the'wave theory in the "Encyclopaedia Britannica" is an acknowledged masterpieco of lucid if compressed expos'-' tion. But his name is not associated with any wido original generalisations; his part had rather been _ to point / but and frequently remove difficulties which have been glossed over or imperfectly realised by earlier investigators, to bring light into tho dark places of established theories, ,to fill up gaps in knowlcdgo and givo tho final polish.