MATERIAL UNIVERSE. 39 



be instantly decomposed, not, however, in this 

 instance, without producing a change on the 

 surface of the earth ; for, the oxygen would be 

 attracted to the metallic surface, and, uniting 

 with it, would oxidize or rust it ; thereby pro- 

 ducing a thin coating, or crust, and for ever 

 depriving it of the brilliant lustre which, till 

 then, it had exhibited. The hydrogen would 

 escape, to be united with more oxygen, and form 

 water. This oxide, or rust, gradually accumula- 

 ting, and being a bad conductor of heat, would 

 materially aid in reducing the temperature of the 

 exterior of the globe. 



While this process was going on, the tempera- 

 ture of the exterior of the earth, becoming con- 

 stantly reduced, would gradually admit the water 

 in a more condensed form, which would event- 

 ually come in contact with it without being 

 decomposed. Ages must, however, have elapsed 

 before the water could have been suffered to 

 approach the heated exterior in a liquid state ; 



