=Young=, Thomas, Principal Forbes's opinion of, 194;
birth and parentage, 194;
early education, 195;
becomes a London medical student, 199;
paper on the power of adjustment of the eye, 199;
elected F.R.S., 200;
visit to Cornwall, 201;
first visit to the Duke of Richmond, 201;
enters the Medical School at Edinburgh, 202;
declines secretaryship to the Duke of Richmond, 202;
visits Gordon Castle, 204;
visits Inverary Castle, 205;
enters the University of Goettingen, 206;
examination in medicine at Goettingen, 207;
enters Emmanuel College, 207;
discovers the principle of interference, 208;
appointed Professor of Natural Philosophy at the Royal
Institution, 174, 210;
lectures at the Royal Institution, 212;
theory of colour-vision, 214;
his colour-top, 215;
colour-diagram, 215;
his Bakerian lectures, 218;
explanation of the rectilinear propagation of light, 221;
of Newton's rings, 222;
eriometer, 223;
explanation of coloured halos, 224;
of the colours exhibited by mother-of-pearl, 224;
interference spectra, 225;
explanation of spheroidal waves in Iceland-spar, 226;
of the colours of thin plates, 227;
hypothesis of an electric ether, 227;
investigations on surface-tension, 229;
modulus of elasticity, 230;
his marriage, 231;
appointed physician in St. George's Hospital, 231;
superintendent of the Nautical Almanack, 232;
death, 233.