54 CHEMISTRY OF THE KOCKS. 



ing in gaseous forms, or they were created in the condition 

 of melted and oxidized masses ready to cool into granite and 

 limestone. The latter supposition will hardly be seriously 

 entertained in these days of free inquiry into the natural causes 

 of tilings. It is now not only conceded, but expected, that 

 science shall have sole jurisdiction in every case where compound 

 bodies are the subject of investigation. To follow them back to 

 the primal laws and elements of their being, to reveal the cause 

 and manner of their birth among the atoms, is now the highest 

 aim of inductive research. On this border-line of inquiry where 

 the known shades off into the unknown and the finite into the 

 infinite, science has of late gained its most signal triumphs. And 

 it scarcely requires a prophetic sense to discern that the ground- 

 work of all systems of scientific knowledge will soon be laid in 

 molecular physics. 



In the constituents of the solid earth we have forms and con- 

 ditions of matter of remarkable composition and complexity. 

 The original materials of the ground, of the rocks, and of the 

 mines, are found to be, in every case, fully saturated chemical 

 compounds. Many of them, as the silicates, are adamantine acids 

 neutralized by alkaline bases harder than the flint. They could 

 not be made more stable, inert, and solid. They are materials 

 that have apparently gone through stupendous changes, activities, 

 and combustions, and at last have settled down to a rest that 

 knows no waking. Science has no duty more legitimate or more 

 imperative than to inquire how these rock-masses came to be 

 where they are, and in the condition they are. 



In pursuing this inquiry, since we find one of the alternatives 

 to be inadmissible, it is necessary to accept the other, namely, 

 that the matter which composes the geological formations 

 preexisted as simple elements, in a gaseous form. Oxygen, 

 which makes up fully one-half the weight of the solid parts 

 of the earth, is and always was a gas in its free state. In 

 regard to the remaining elements that enter into the composi- 

 tion of the rocks, such as silicon, aluminum, calcium, and 

 sodium, they could not all have existed on the earth at the same 

 time as melted liquids ; for the same heat which would hold one 



