John William Strutt
English physicist
November 12, 1842 - June 30, 1919

John William Strutt, the third Lord Rayleigh, was born on November 12, 1842. Rayleigh succeeded Clerk Maxwell as professor physics at the Cavendish Laboratory in Cambridge, England in 1879 and directed the Royal Institution. During his professorship women from Girton and Newnham colleges were for the first time admitted on the same terms as the men.

Rayleigh studied electrochemistry and the chemistry and physics of gases. He studied sound and optics.  He investigated the ratio of the densities of hydrogen and oxygen, and measured the density of nitrogen. His observation that nitrogen prepared from the atmosphere was more dense than nitrogen prepared from pure ammonia led the way to the discovery of the rare gases with William Ramsay and a Nobel Prize in 1904.