=Boyle=, Hon. Robert, birth, 8; conversion, 11; first air-pump, 17; conception of the constitution of the air, 19; experiments with the air-pump, 19, _et seq._; argument on the cause of a vacuum, 23; experiments establishing his law, 25; statement of his law, 29; observations on cold, 32, and on the expansion of water in freezing, 33; experiments on induced magnetism, 34; the province of experimental science, 37. Boyle's law, 29. Brocklesby, Dr., death of, 208. Brougham's criticisms of Thomas Young, 218. Bumper, electrical, 80. C. Camera obscura, invention of, 2. Canada balsam, stresses in, 298. Candle-flame, effect of, in discharging electricity, 75. Capacity, electrical, 137; Franklin's experiments on, 81, 89; Cavendish's unit of, 138; Cavendish's measures of, 134, 138; of disc, measured by Cavendish, 134. Capillarity, 228. Cascade method of charging Leyden jars, 77. =Cavendish=, Hon. Henry, F.R.S., birth and parentage, 126; social habits, 127; appointed member of the R.S. Committee on Lightning-Conductors, 131; elected Foreign Associate of the French Institute, 132; death, 133; proof of the law of inverse squares, 135; experiment with the spheres repeated by MacAlister, 137; experiments on the torpedo, 140; experiments on the resistance of conductors, 142; discovery of Ohm's law, 143; view of latent heat, 144; apparatus for determining the melting point of mercury, 145; the Cavendish experiment, 146. Cavendish experiment, 146; Laboratory, 288; Manuscripts, 134; Maxwell's work on the Manuscripts, 293. City Philosophical Society, joined by Faraday, 245; Faraday's lectures to, 251. Cold, Boyle's observations on, 32. Collinson, Peter, present of, to the Library Company, 72. Colour-blindness, Maxwell's experiments on, 296. Colour-box, Maxwell's, 297. Colours, effect of, on absorption of sun's rays, 99, 186. Colours of the spectrum mixed by Boyle, 31. Colour-top, Maxwell's, 284, 295; Young's, 215. Colour-vision, Maxwell's theory of, 294; Young's theory of, 214. Commonplace-book, Faraday's, 253. Compound-interest principle, 316. Condenser, use of, in induction coils, 321. Conduction of heat, Rumford's experiments on, 186. Conductors, multiple, flow of electricity through, 141. Conductors necessarily opaque, 307. Conservation of energy, Maxwell's statement of the principle of, 325. Copley Medal awarded to Franklin, 66, 74. Cork, Earl of, autobiography of, 5. Creeping of electricity on glass, 139. Crystalline lens, fibrous structure of, 200; mode of adjustment of, 201. Cuneus's discovery of the Leyden jar, 4. D.