18 Evolution of Matter 



§9. The Evolution of Matter. 



To our picture of the making of worlds must be 

 added that of the evolution of matter. It is now 

 known that the radio-active substances are continu- 

 ally producing from themselves other chemical ele- 

 ments. They cannot be stopped doing so or provoked 

 to do so ; therefore while the unchangeableness of the 

 elements has been overthrown, their unchange ability 

 remains, as Professor Soddy says, in a limited sense 

 true. 



In some cases a chemical genealogical tree is 

 known. Uranium may produce ionium, which pro- 

 duces radium. Or uranium may produce protactin- 

 ium, which produces actinium. From thorium may be 

 produced lead, and from radium another lead, and 

 from actinium yet another lead. 



The epoch-making conclusion has been reached 

 that the atoms of the different elements are not dif- 

 ferent in essential nature, but are constituted out of 

 different numbers and arrangements of similar units. 

 The atom is a planetary system in which the planets 

 are represented by electrons (unit charges of nega- 

 tive electricity) circulating around a central body, 

 which consists of hydrogen nuclei or protons and 

 more electrons. Many authorities declare that the 

 hydrogen nuclei or protons are just positive charges 

 of electricity. All the world is one. 



Here is a unification not less overpowering than 

 the unity of a solar system or a galaxy of stars ; we 

 have come close to the stuff out of which worlds are 



