ON THE STRUCTURE OF ATOMS. 85 



bodies attract eacli other. All the other elements vary in their 

 electric properties between these two, and the fact that they do 

 vary shows that they are composed in varying proportions of 

 parts or substances that attract or repel. 



There is indubitable evidence that the earth was-once a mass 

 of melted rock material. The crystalline structure of all the 

 primitive rocks shows this. They could not have crystallized 

 except they had been previously in a state of fusion. There is 

 also evidence that in still earlier periods all the matter forming 

 the earth's crust was in a gaseous state. In no other condition 

 could all the silicon and calcium and every other mineral have 

 become completely oxidized. The chemistry of the rocks is a 

 complete vindication of the nebular hypothesis. The moon has 

 gone through the same fiery ordeal, as the volcanic nature of its 

 surface gives evidence. The planet Mars is exactly like the 

 earth in all its main features, and in all probability reached this 

 similitude through the same cycle of changes that the earth has 

 gone through. The sun is to-day still in the later stages of its 

 gaseous state. Iron, calcium, magnesium and sodium are still 

 vapors on its heated surface. Every indication goes to show that 

 all the bodies of our solar system were once in gaseous or nebu- 

 lous conditions. 



Now either the material substances composing each planet and 

 satellite were created separate from all the others and around 

 each one's own center of gravity, or else the matter of the whole 

 system was once equally diffused through all the space comprised 

 within the planetary orbits, with but one center of gravity. 



In regard to the first alternative we must of course acknowl- 

 edge that it is impossible to argue against the assertion of direct 

 creation ; because certainly the Creator could, if he had seen fit, 

 have spoken into being every part of the universe in fully devel- 

 oped conditions. But inasmuch as he has not done so in any 

 single instance that has been closely investigated, but has left his 

 purposes to be worked out by the laws which he has ordained, so 

 I maintain that if we can form a reasonable and probable theory 

 of the formation of the planetary worlds out of a more general 

 diffusion of nebular matter, we are fully authorized to adopt it. 



