ELECTRONS 75 



of the universe, and talked of him as a microcosm ; 

 and the atom is in very truth a microcosm, or at 

 least a miniature solar system. Probably in the 

 centre of the atom there is a corpuscle like a sun, and 

 round this central sun the other corpuscles whirl. 

 The velocity with which the corpuscles gyrate and 

 rotate is enormous, and the power developed 

 correspondingly colossal. When the forces within 

 the atom are in equilibrium they are known only 

 as apparently passive matter ; but when this 

 equilibrium is disturbed, and when the corpuscles 

 become dissociated, as occurs in radium, then the 

 intra-atomic energy becomes more apparent. 



The case of radium is especially interesting. It 

 has a large, and therefore presumably unstable, 

 atom ; and the a particles it emits seem identical 

 with helium (an element which was discovered in 

 the sun before it was discovered upon earth), while 

 the residue of the radium atom left after the emis- 

 sion of sundry a, /3, and 7 rays seems identical with 

 lead. Thus helium and lead are products of the 

 decomposition of a larger atom, the atom of radium ; 

 and thus, again, we have a verification of the dream 

 of the alchemists with regard to the transmutation 

 of elements, and a verification, too, of the doctrine 

 of Albertus Magnus, that the birth of one element 

 is in some way due to the corruption and death of 

 another. Could anything be more amazing } Not 



