778 



INDEX. 



of, 349 ; experiments on, 444 ; 

 meclianical equivalent of, 568. 



Heavy glass, 588, 609. 



Helmholtz, on microscopy, 406 ; 

 nndulatious, 414 ; sound, 476. 



Hcmihedral crystals, 649. 



Herschel, Sir John, on rotation of 

 plane of polarisation of light, 129, 

 630 ; quartz ciystals, 246 ; nu- 

 merical precision, 273 ; photo- 

 metry, 273 ; light of stars, 302 ; 

 actiuometer, 337 ; mean and. 

 average, 303 ; eclipses of Jupiter's 

 satellites, 372 ; law of error, 377 ; 

 error in observ.itions, 392 ; on 

 observation, 400 ; moon's influ- 

 ence on clouds, 410 ; comets, 411 ; 

 spectrum analysis, 429 ; collective 

 instances, 447, principle of forced 

 vibrations, 451, 663 ; meteoro- 

 logical variations, 489 ; double 

 stars, 499, 685 ; direct action, 

 502 ; use of theory, 508 ; ether, 

 615; cxjjerimentum, crucis, 519; 

 interference of light, 539 ; inter- 

 ference of sound, 540 ; density of 

 earth, 567 ; residual phenomena, 

 569 ; helicoidal dissymmetry, 

 630 ; fluorescence, 664. 



Ilindenburg, on combinatorial 

 analysis, 176. 



Hipparchus, used method of repeti- 

 tion, 289 ; longitudes of stars, 294. 



Hippocrates, area of hniule, 480. 



History, science of, 760. 



Hobbes, Thomas, definition of cau.sn, 

 224 ; definition of time, 307 ; on 

 hypothesis, 510. 



Hofmaim, unit called crith, 321 ; 

 on prediction, 544 ; on anomalies, 

 670. 



Homogeneity, law of, 159, 327. 



>iooke, on gravitation, 436, 581 ; 

 philosopliical method, 507 ; on 

 strange things, 671. 



Hopkinson, John, 194 ; method of 

 interfiolatioii, 497. 



Horrocks, use of mean, 358 ; use 

 of liypothesis, 507. 



Hume on pei-c(qitioii, 34. 



Hutton, density of earth, 566. 



]^uxk■y, Professor Thomas, 764 ; 

 on hypothesis, 509; chis.sification, 

 676 ; mammalia, 682 ; palicon- 

 tology, 682. 



Huyghens, theory of pendulum, 302 ; 



pendulum standard, 315 ; cycloidal 

 pendulum, 341 ; differential me- 

 thod, 344 ; distant stars, 405 ; use 

 of hypothesis, 508 ; philoso]ihical 

 method of, 685 ; ou analogy, 

 639. 



Hybrids, 727. 



Hydrogen, expansion of, 471 ; re- 

 fractive power, 527 ; metallic 

 nature of, 691. 



Hygrometry, 563. 



Hypotheses, use of, 265, 504 ; sub- 

 stitution of simple hypotheses, 

 458 ; working hypotheses, 509 ; 

 requisites of, 510; descriptive, 

 522, 686 ; representative, 624 ; 

 prohaliility of, 559. 



Identical propositions, 119. 



Identities, simple, 37 ; partial, 40 ; 

 limited, 42 ; simple and partial, 

 111 ; inference from, 51, 55. 



Identity, law of, 5, 6, 74 ; expres- 

 sion of, 14 ; propagating power, 

 20 ; reciprocal, 46. 



Illicit process, of major term, 65, 

 103 ; of minor terra, 65. 



Immediate inference, 50, 61. 



Imperfect induction, 146, 149. 



Inclusion, relation of, 40. 



Incommensural)le quantities, 275. 



Incompossible events, 205. 



Independence of small effects, 475. 



Independent event.s, 204. 



Indestructibility of matter, 465. 



Indexes, cla.ssification by, 714; 

 formation of, 717. 



India-rubber, properties of, 545. 



indirect method of deduction, 49, 

 81 ; illustrations of, 98 ; fallacies 

 analysed by, 102 ; the test of 

 equivalence, 115. 



Induction, 11, 121 ; symbolic state- 

 ment of, 131 ; perfect, 146 ; im- 

 l)erfect, 149 ; philo.sophy of, 218 ; 

 grounds of, 228 ; illustrations of, 

 229 ; quantitative, 483 ; problem 

 of two classes, 134 ; problem of 

 three classes, 137. 



Inductive truths, classes of, 219. 



Inequalities, reasoning by, 47, 163, 

 165-166. 



Inference, 9 ; general formula of; 

 17 ; immediate, 50 ; with two 

 simple identities, 51 ; from 

 simple and partial identity, 53 ; 



