INDEX 313 



Hertz, G 299 



Heinrich 293, 297 



Hertzian waves 293 



Hess's law 285 



Hittorf 30 



Hoeffding, Harald 41 



Hoff, H. J., van't 59, 303 



Holmyard, E. J 150, 296 



Hull, A. W 304 



Human body, cells in 261 



chemical constituents of the 100, 102 



brain, shrinking of the 61 



embryo, water contents of the 61 



Huxley, Thomas Henry 65, 205, 298 



Hydrocarbons 52, 53 



Hydrogen 52, 103, 104, 105, 108, 282 



atom 88, 94, 104, 105 



ions 108, 116 



molecule 94, 121 



how split 105 



nuclei 103 



nucleus 85, 108 



H2+-ion 109 



constituents of 108 



Hydrolysis 293 



Hylozoism 165 



Hypothesis, the place of, in science 23-25 



Hypotheses, essential, of the Gaskell theory of life 270 



Hysteresis 293 



Immortality of cells 147-149 



unicellular organisms 147 



Infancy, cause of difference in length between man's and ape's. . . 185-188, 264 



length of, standard for rating intelligence of a race 189-194, 196 



Intelligence of a race, standard for rating 189-194, 196 



Intergrades 242 



Iodine 101 



Ion 90 



Ions, critical concentration of, postulated by the Gaskell theory of 



life 117, 121, 178, 235 



Ionization 100, 106, 107 



in liquids 106, 107, 120 



of gases 106, 107 



