INDEX. 



261 



Excited activity 

 Exradio 



Faraday on transmutation 

 Fraunhofer's lines 



PAGE 

 122 

 147 



140 

 198 



Gallium, successful prediction 



of 34 



Gamma-rays, properties of 110 

 Gamma-rays compared with 



X-rays 110 



Gases, conductivity of 47 



Germanium, successful predic- 

 tion of 34 

 Gravitation 189 



Halogens, relations of 32 



Helium, a decomposition prod- 

 uct of radium 124 

 Helium, discovery of 124 

 Helium in radio-active minerals 124 

 Helium from radium 147 

 Helium, its existence in the 



stars 221 



Helium, position of, in periodic 



table 38 



Helium, the possible substance 



of the alpha-rays 124 



Helium, spectrum of 125 



Heating effect caused by cor- 

 puscles 71 

 Heat emitted by radium 172 



Induced radio-activity 113 

 Inert elements, position of, in 



periodic law 38 

 Inert elements, corpuscular 



explanation of 168 



Inertia of matter 179 



Inertia of electricity 180 

 Inorganic evolution indicated 



in periodic law 41 



PAGE 

 Inorganic evolution, relation 



of, to organic evolution 213 



Inorganic devolution 217 et seq. 

 Inorganic devolution, evidence 



for 218 



Inorganic devolution, its rela- 

 tion to inorganic evolution 222 

 Interatomic energy, discovery 



of 172 et seq. 



lonisation, definition of 50 



Ions, gaseous 48 et seq. 



Iron, spectrum of, in the sun 200 

 Iron, spectrum of, in the sun 

 spots 201 



Knowledge, the new, the valid- 

 ity of 252 et seq. 



Lenard rays 72 



Light, the mechanical pressure 



of 232 



Light, undulatory theory of 4 

 Lockyer, Sir Norman 197 



Magnesium, spectrum of, in the 



sun 203 



Magnetism 186 



Mass, law of the conservation 



of 3 



Mass, conservation of, recon- 

 sidered 249 

 Mass electrical in its origin 184 

 Mass, increase of, with velocity 182 

 Mass, the increase of, with 

 velocity; experimental veri- 

 fication 183 

 Matter, preliminary definition 



of 2 



Matter, the mystery of 15 



Matter, electrical nature of 



179 et seq. 

 Matter, transmutation of 137 et seq. 



