Halos, coloured, Young's explanation of, 224.
Hawksbee's observations on capillary attraction, 228.
Heat, a form of energy, 32;
generated by friction in vacuum, 32;
generated by friction, Rumford's experiments on, 189.
Herapath's explanation of gaseous diffusion, 299.
Herschel's, Sir John, comments on Young's principle of interference,
208.
Hicks's, Principal, investigations on the influence of temperature
on gravitation, 184.
Hieroglyphics, Young's work on, 234.
Hobbes, opposition of, to Boyle, 25.
Hollow conductor, Franklin's experiments on, 91;
Cavendish's experiments on, 135;
Faraday's experiments on, 270.
Honorary degrees conferred on Franklin, 66, 101.
Hooke's law, 229.
Hooke, Theodore, founds the Royal Society, 14.
Huyghens's explanation of double refraction, 219;
principle, 218.
Hydrogen, electro-chemical equivalent of, 267.