John William Strutt
John William Strutt (1842-1919) 3rd Baron Rayleigh, referred to as Lord Rayleigh, OM, was an English physicist who, with William Ramsay, discovered argon, an achievement for which he earned the Nobel Prize for Physics in 1904.
He also discovered the phenomenon now called Rayleigh scattering, explaining why the sky is blue, and predicted the existence of the surface waves now known as Rayleigh waves.
1919 Obituary 
JOHN WILLIAM STRUTT, third BARON RAYLEIGH, P.C., O.M., D.C.L., LL.D., F.R.S., was born at Langford Grove, Essex, on 12th November 1842.
He was educated at Trinity College, Cambridge, and was Senior Wrangler and Smith's Prizeman in 1865. Twelve months later he was elected to a Fellowship at Trinity College, which he retained for four years.
In 1873 he was chosen a Fellow of the Royal Society, and succeeded Professor Clerk Maxwell as Cavendish Professor of Physics in 1879, which post he held until 1884. During that period he carried out valuable investigations for the Committee of the British Association to improve the construction of the practical standards for electrical measurement, in which he was assisted by Professor Schuster and Dr. Glazebrook.
In 1884 he served as President of the British Association at Montreal, and soon after his return from Canada he was elected one of the Secretaries of the Royal Society, a position he held until 1896.
In 1887 he became Professor of Natural Philosophy at the Royal Institution in succession to John Tyndall, and held this position until 1905, when he became President of the Royal Society.
Three years later the University of Cambridge elected him Chancellor in place of the late Duke of Devonshire.
The Nobel Prize was awarded to him 1904. He held the Copley Medal, was a Knight of the Prussian Order Pour Is Merits and of the Legion d'Honneur, and was made a Privy Councillor in 1905. He was Chairman of the Treasury Committee which recommended the establishment of the National Physical Laboratory, and subsequently presided over its Executive Committee.
He acted as Chief Gas Examiner under the Metropolitan Gas Acts, and sat on the Board of Trade Committee which reported on the methods of testing gas.
His best known and most remarkable achievement was the discovery of argon in the atmosphere, which was announced in 1894, and in the later stages of his investigation he was associated with the late Sir William Ramsay.
In recognition of the value of his discoveries, Lord Rayleigh's name was included in the original list of twelve upon whom King Edward VII conferred the Order of Merit in 1902. He was nominated an Honorary Life Member of this Institution in 1896.
His death occurred at his Essex home, Terling Place, near Witham, on 30th June 1919, in his seventy-seventh year.