INDEX. 



435 



Darkness converted into light, 119. 



Davy, Sir H., xxvii., 4, 134, 245. 



Day, variation in length of the, 303. 



De Candolle, 57. 



Decay restores heat to the universe, 419. 



De la Rive, 57. 



Despritz, M., 76. 



Democritus, 127. 



Descartes, xi. 



Desormes, Clement, 75. 



Development of the embryo ; derivation 



of its force, 427. 

 Diathermancy, 278. 

 Diiferentiation in animal development, 



409. 



Diminution of the earth's volume, 303. 

 Discovery, conditions of, 104. 

 Distinctions among the forces imperfect, 



178. 



Dove, M., 126. 

 Dufour, M., 96. 

 Dulong and Petit, 189. 

 Dynamic function of the germ, 412. 



Earth, age of, 245. 



form of, 297. 



Earth's interior heat, 236, 300. 



proofs of, 302. 



reasonableness of, 803. 



Effect of electrical discharge upon gases, 



Electrical induction, 84. 



Electricity, limitation of the term, 35. 



from caoutchouc, 35. 



the link among the other forces, 87. 



as initiating other forces, 88. 



what is it? 83. 



produces chemical decomposition, 84. 



atmospheric, 87. 



intensity of, 89. 



effect upon the terminals, 90. 



molecular changes of conductors, 95. 



hypothesis of a fluid unnecessary, 98, 



101. 



animal, 99. 



in what it consists, 101. 



initiates motion, 104. 



and heat, 106. 



and light, 107. 



produced by blowpipe flame, 155. 

 Electro-chemical equivalence, 394. 



equivalents of power, 373. 

 Electro-magnetic equivalence, 393. 

 Emotions, correlations of, xxxiv. 

 Ethereal medium, 123, 242, 271, 347. 



objections to, 133. 



Equivalent, meaning applied to the term, 



829. 



Ericsson, Mr., 78. 



Erman on friction of homogeneous sub- 

 stances, 33. 



Essences, the search for, 14. 

 Euler, Leonard, 123. . 

 Events can never be repeated, 193 

 Expansion, inequality of, 54. 



Falling bodies, highest velocity of, 337. 

 phenomena of, 818. 



force, 253, 348. 



Faraday, Dr., discoveries of, 6, 85. 144, 

 145. 



biographical notice of, 858. 

 Favre, M., 371. 



Faye's theory of comets, 41. 

 Flower figures in ice, 50. 

 Fizeau, M., 129. 

 Forbes, Jas. D., xix. 

 Force, indestructibility of, xii. 



use of the doctrine, xiii. 



importance of neAV views of, xxx. 



Grove's definition of, 19. 



imparted to machines, 218. 



what is it? 251. 



definition of, 335. 



meaning of the term, 330, 379. 



living and dead, 333. 



animal, derived from decomposition of 



food, 432. 

 Foucault, M., 129. 

 Fourier, M., 309. 

 Franklin, Dr,, xvii. 

 Fresnel on heat repellancy, 41. 

 Friction, definition of, 30. 



producing electricity, 33. 



of homogeneous substances, 33. 



heat of, 3S9. 



G 



Gassiot, Mr., 59, 135. 

 Gay Lussac, M., 167. 

 Germ -force, 411. 

 Germination, dynamics of, 413. 

 Generative force in insects, 425. 

 Gravity implies a plenum, 368. 



in relation to other forces, 170, 258. 



is it a force ? 339, 340, 341. 



but half understood. 366. 



relation to conservation of force, 363. 

 Grove, aim of his essay, 19. 



biographical notice of, 2. 



claims of, 5. 



electrical images on glass, 86. 



discoveries on the relations of heat to 



the gases of water, 65. 

 Grotthns, 163. 



Growth in the mammalia, 428. 

 Guillemin, M., 151. 



II 



Heat, material hypothesis of, annihilated 

 by Kumford, xxiii., xxiv. 



definition of, 39. 



dynamical effects of, 40. 



latent, 41, 348. 



influence of structure over the con- 



dition of, 57. 



produces the various forces, 57. 



reflection of, 61. 



converted into light, 63. 



