474 



INDEX. 



442 ; probable, 451 ; constant, 460; 

 theory of, ii. 90. 

 Ether, friction of, ii. 254. 

 Euclid, axioms, i. 183 ; incommensur- 

 ables, 319; right angle, 358; ana- 

 logy, ii. 289. 



Euler, on knowledge, i. 273; gravity, 

 274; ii. 8 1 ; medium of light, 

 143; corpuscular theory, 152. 

 Exceptions, in induction, i. 152 ; classes 

 of, ii. 308 ^imaginary or false, 309; 

 apparent, 313; singular, 316; diver- 

 gent, 320 ; accidental, 324 ; novel, 

 328; limiting, 331; real, 336; un- 

 classed, 338. 



Excluded middle, law of, i. 7. 



Exclusive alternatives, i. 234. 



Experiment, ii. 2, 22 ; simplification of, 

 30 ; failure in, 33 ; blind or test, i. 

 402 ; ii. 43 ; negative results of, 45 ; 

 limits of, 48 ; collective, 57 ; discord- 

 ance of, 198. 



Experimentum crucis, ii. 135, 337- 



Explanation, ii. 157, 166. 



Extent of, logical terms, i. 31 ; propo- 

 sitions, 57, 



Extrapolation, ii. 1 20. 



F. 



Factorials, i. 202. 

 Fallacies, i. 74, 117. 

 Faraday, Michael, on gold-leaf, i. 346 ; 

 gravity, 396 ; ii. 236 ; magnetism 

 of gases, i. 407 ; lycopodium, ii. 25 ; 

 electrolysis, 29, 32, 83 ; electric poles, 

 29 ; electro-magnetism, 31, 184, 274 ; 

 polarized light, 31, 318; precautions 

 in experiment, 40 ; lines of force, 58 ; 

 Arago's experiment, 1 70 ; velocity 

 of electricity, 1 80 ; his researches, 

 223 ; reservation of judgment, 240 ; 

 heavy glass, 261 ; electricity, 264 ; 

 radiant matter, 304 ; hydrogen, 366. 

 Fatality, i. 305. 

 Figurate numbers, i. 212, 214. 

 Figure of earth, ii. 76, 207. 

 Fizeau, Newton's rings, i. 347 ; ii. 227 ; 

 quartz, i. 367 ; revolving mirror, 349 

 Flamsteed, i. 314 ; use of wells, 342 

 standard stars, 351 ; parallax of pole 

 star, 391 ; choice of observations 

 415 ; instruments, 456 ; solar eclipses 

 ii. 109. 



Fluorescence, ii. 332. 

 Forbes, J. D., i. 286 ; ii. 89, 454. 

 Force, unit of, i. 375. 

 Fossils, ii. 327. 



Foucault, revolving mirror, i. 349 



pendulum, 396 ; ii. 41 ; velocity o 



light, 53, 202. 



Fourier, theory of heat, ii. 89, 438. 



Fowler, Professor, inductive inference, 

 i. 261 ; method of variations, ii. 51. 



Freezing mixtures, ii. 183. 



Fresnel, inflexion of light, ii. 27; double 

 refraction, 59 ; undulatory theory, 



Friction, determination of, i. 401 ; heat 

 of, ii. 22, 187. 



Functions, definition of, ii. 113; dis- 

 covery of, 121. 



G. 



Galileo, falling bodies, i. 333; differ- 

 ential method, 399; projectiles, n. 

 85 ; gravity, 254; continuity, 270. 

 Galton, Francis, i. 214, 373; ii. 3 21 - 

 Galvanometer, i. 407. 

 Gas, ii. 90, 250, 266, 320, 334. 

 Gauss, use of mirror, i. 334 ; pendulum 

 experiments, 370; ii. 81 ; law of 

 error, i. 436 ; constant errors, 461. 

 Gay-Lussac, barometer, i. 401 ; law of, 



ii. 274 ; boiling point, 325. 

 Genealogical tree, ii. 407. 

 General names, twofold meaning of, 



i. 31. 

 General principles, ii. 309 ; reasoning 



by, 243. 



Generalisation, ii. 242, 389 ; two mean- 

 ings of, 246 ; value of, 248 ; hasty, 

 278. 



Genius, ii. 219, 321. 

 Genus, ii. 376 ; generalissimum, 379, 



382 ; natural, 414. 

 Geology, ii. 327, 335, 337 > negative 



arguments in, 18. 

 Geometric mean, i. 418. 

 Geometry, reasoning in, i. 183, 268, 309. 

 Gilbert, Copernican system^ i. 287 ; 

 magnetism, ii. 41 ; on experiment, 55. 

 Gold-assay process, ii. 45. 

 Gold-leaf, i. 346. 

 Gradation of character, ii. 410. 

 Graham, Professor, ii. 267, 366. 

 Grammar, rules of, i. 37; ii. 3 2 8; 



equivalents in, i. 138. 

 Granite, classification of, ii. 422. 

 Graphical method, ii. 116. 

 Gravity, ii. 29, 75, 95, 9 6 > H 1 . M4 

 254, 313; measure of density, i. 371, 

 375 ; uniformity of, ii. 36, 56 ; Hooke's 

 experiments, 46 ; law of, 80 ; Fara- 

 day's experiments, 236. 

 Great Britain steamship, voyages of, 



Grove, ii. 267, 268 ; magnetism, i. 397 ; 

 medium of light, ii. 143. 



H. 



HaUey's Comet, ii. 172, 315. 

 Hamilton, Sir William, on reasoning, 



