475 



i. 136; free will, 257; quantification 

 of predicate, ii. 387." 



Hamilton, Sir W. Rowan, ii. 175. 



Haughton, Rev. S., on muscular exer- 

 tion, ii. 114. 



Heat, ii. 297 ; unit of, i. 378; measure- 

 ment of, 405 ; mechanical equivalent 

 of, ii. : 1 1. 



Heavy glass, ii. 235, 260. 



Helmholtz, sound vibrations, ii. 8, 20, 

 98. 



Hereditary descent, ii. 407. 



Herschel, Sir J. F. W., plagihedral 

 quartz crystals, i. 148, 283 ; density 

 of earth, 210 ; photometry, 316, 

 352; numerical precision, 317; unit 

 of length, 367 ; actinometer, 389 ; 

 use of mean, 42 1 ; method of least 

 squares, 437 ; double stars, 457; ii. 

 125 ; active and passive observation, 

 2 ; fluorescence, 2 ; full moon, 15 ; 

 comets, 16; spectrum, 39 ; collective 

 instances, 59 ; principle of forced 

 vibrations, 65, 332 ; meteorological 

 variations, 112; direct action, 129; 

 use of theories, 136 ; ethereal 

 medium, 145 ; experimentum crucis. 

 149 ; interference of light, 175 ; 

 interference of sound, 1 76 ; residual 

 phenomena, 212; discovery by ana- 

 logy, 286. 



Hindenburg, combinatorial analysis, i. 

 198. 



Hipparchus, i. 337 ; ii. 306 ; use of 

 moon, i. 342. 



Hobbes, cause, i. 257 ; time, 359 ; 

 hypothesis, ii. 138. 



Hofmann, crith, i. 374; prediction, ii. 

 181 ; anomalous vapour densities, 340. 



Homogeneity, law of, i. 179. 



Hooke, ii. 153, 342; gravity, 46; 

 philosophical method, 135 ; memory, 

 288. 



Horrocks, use of means, i. 415; hypo- 

 thesis, ii. 135 ; planetary motions, 

 281. 



Huxley, on classification, ii. 348, 354. 



Huyghens, Saturn's satellites, i. 341 ; 

 ii. 280; pendulum, i. 353, 369; 

 cycloidal pendulum, 394 ; differential 

 method, 399 ; stars, ii. 8 ; projectiles, 

 85 ; philosophical method, 135 ; un- 

 dulatory theory, 151 ; double refrac- 

 tion, 231 ; analogy, 301. 



Hybrids, ii. 416, 417. 



Hydrogen, dilatation of, ii. 91; refrac- 

 tive power, 1 60; metallic nature of, 

 366. 



Hygrometry, ii. 206. 



Hypothesis, use of, i. 262 ; requisites 

 of, 307 ; substitution of simple, ii. 

 74; representative, 156; descriptive, 

 359- 



I. 



Identity, expression of, i. 18; pro- 

 pagating power, 24 ; simple, 44 ; 

 partial, 47; limited, 51; inference 

 from, 6 1, 66. 



Illicit process, i. 77, 119. 



Incommensurables, i. 319. 



Independence, of events, i. 233 ; of 

 small effects, ii. 96. 



Indexes, value of, ii. 405. 



India-rubber, ii. 182. 



Indifferent circumstances, abstraction 

 of, i. 112 ; exclusion of, ii. 26. 



Indirect method, i. 133; ii. 370; rules 

 of, i. 105; illustrations of, 113. 



Induction, i. 13, 70, 139 ; inverse 

 nature of, 14 ; of partial identities, 

 149 ; perfect, 164 ; imperfect, 168 ; 

 grounds of, 262. 



Inequality, reasoning by, i. 184, 186. 



Inference, process of, i. 1 1 ; immediate, 

 60; from two simple identities, 61 ; 

 sum of predicates, 73 ; with disjunc- 

 tive propositions, 90 ; indirect method 

 of, 95; nature of, 136; mathe- 

 matical, 183. 



Infima species, ii. 380, 382. 



Infiniteness of universe, ii. 431. 



Inhabitants of planets, ii. 301. 



Instantiae, citantes, evocantes, radii, 

 curriculi, i. 313; monodicae, irregu- 

 lares, heteroclitae, ii. 260 ; clan- 

 destinae, 262. 



Insufficient enumeration, i. 199. 



Insulators, ii. 265. 



Intension, of logical terms, i. 31 ; pro- 

 positions, 57. 



Interpolation, ii. 120. 



Inverse, operation, i. 140 ; problem, 



i?4- 



Iodine, ii. 155, 366. 

 Iron, magnetic power of, ii. 40. 

 Isomorphism, ii. 312, 330. 



J. 



Jet of water, ii. 9, 58, 60. 



Jevons, W. S., cirrous clouds, ii. 15 ; 

 elevated rain-guage, 40; experiments 

 on liquids, 60 ; experiments on 

 muscular exertion, 114; cometary 

 retardation, 213; microscopic move- 

 ments, 264. 



Joule, ii. 179, 182, 187, 197; thermo- 

 pile, i. 349 ; heat of compression, 

 350 ; temperature of air, 398 ; ex- 

 periments on heat, 402 ; measure- 

 ment of temperature, ii. 47 ; gases, 

 56 ; equivalent of heat, 211. 



Jupiter, satellites of, ii. 298, 322 ; 

 eclipses of satellites, i. 433 ; figure 

 of, ii. 196. 



