MATERIAL UNIVERSE. 47 



sufficient to melt metallic bodies will expel these 

 gases from such bodies. Admitting, then, that 

 these gases then existed around the molten mass, 

 we should suppose they might be attracted to 

 that body in the ratio of their relative specific 

 gravity or weight ; and, as carbonic acid gas is 

 the heaviest, it would, consequently, as the 

 earth's temperature became reduced, be the first 

 to approach it, and become united with it. But 

 the earth's surface was not yet prepared to admit 

 the union of this gas with it ; the fact being 

 established, by the laws of chemistry, that me- 

 tallic bodies will not combine with this gas, nor 

 with any acid, until such bodies are first oxi- 

 dized, or, in other words, until they form a union 

 with oxygen. To increase the density of oxy- 

 gen gas, so as to allow it to overcome the resist- 

 ance of the more dense carbonic acid gas, became 

 necessary. And how was this effected ? By 

 combining the two gases, oxygen and hydrogen, 

 and forming water. This combination was ren- 



