367 



Gilbert, Dr., of Colchester, his 

 knowledge of magnetism 

 and electricity, 112. 



Gravitation, law of, a physical 

 axiom of a very high and 

 universal kind, 98. Influ- 

 ence of, decreases in the in- 

 verse ratio of the square of 

 the distance, 123. 



Greece, philosophers of, their 

 extraordinary success in 

 abstract reasoning, and their 

 careless consideration of 

 external nature, 105. Their 

 general character, 106. Phi- 

 losophy of, 108. 



Grimaldi, a Jesuit of Bologna, 

 his discovery of diffraction, 

 or inflection of light, 252. 



Guinea and feather experi- 

 ment, 168. 



Gunpowder, invention of, 55. 

 A mechanical agent, 62. 



Haarlem lake, draining of, 6 1 . 



Harmony, sense of, 248. 



Head,captain, anecdote of,84. 



Heat, 193. Radiation and 

 conduction of, 205. One 

 of the chief agents in 

 chemistry, 310. Our ig- 

 norance of the nature of, 

 310. Abuse of the sense 

 of the term, 311. The ge- 

 neral heads under which it 

 is studied, 312. Its most 

 obvious sources, 312. Ani- 

 mal heat, to what process 

 referable, 813. Radiation 

 and conduction of, 314. 

 Solar heat differs from ter- 

 restrial fires, or hot bodies, 

 315. Principal effects of, 

 317. The antagonist to mu- 

 tual attraction, 322. Latent 

 heat,322. Specific heat,323. 



Herschel, sir William, his ana- 

 lysis of a solar beam, 314. 



Hipparchus, his catalogue of 

 stars, 276. 



Holland drained of water by 

 windmills, 61. 



Hooke almost the rival of 

 Newton, 116. 



Huel Towan, steam-engine 

 at, 59. 



Huyghens, his doctrine of 

 light, 207. Ascertains the 

 laws of double refraction, 

 254. 



Hydrostatics, first step to- 

 wards a knowledge of, made 

 by Archimedes, 231. Law 

 of the equal pressure of 

 liquids, 232. General ap- 

 plicability of, 232. 



Hypothesis, not to be deterred 

 from framing them, 196. 

 Conditions on which they 

 should be framed, 197. 

 Illustrated by the laws of 

 gravitation, 1 98. Use and 

 abuse of, 204. 



Induction, different ways of 

 carrying it on, 102. Steps 

 by which it is arrived at on 

 a legitimate and extensive 

 scale, 1 1 8. First stage of, 

 1 44. Verification of, 1 64. 

 Instanced in astronomy, 

 1 66. Must be followed intc 

 all its consequences, and 

 applied to all those cases 

 which seem even remotely 

 to bear upon the subject of 

 enqui ry , 1 7 3 . Nature of the 

 inductions by which quan- 

 titative laws are arrived at, 

 1 76. Necessity of induc- 

 tion embracing a series of 

 cases which absolutely in- 



