THROUGH THE GEOLOGIST’S EYES 
at one time in the original granite, or in the primor- 
dial seas, or in the primordial atmosphere, or in 
the heavens above, or in the interior of the earth 
beneath. We must sweep the heavens, strain the 
seas, and leach the air, to obtain all this material. 
Evidently the growth of these rocks has been mainly 
a chemical process —a chemical organization of 
preéxisting material, as much so as the growth of 
a plant or a tree or an animal. The color and tex- 
ture and volume of each formation differ so radically 
from those of the one immediately before it as 
to suggest something more than a mere mechanical 
derivation of one from the other. New factors, 
new sources, are implied. “‘The farther we recede 
from the present time,” says Lyell, “and the higher 
the antiquity of the formations which we exam- 
ine, the greater are the changes which the sedi- 
mentary deposits have undergone.” Above all have 
chemical processes produced changes. This con- 
stant passage of the mineral elements of the rocks 
through the cycle of erosion, sedimentation, and re- 
induration has exposed them to the action of the 
air, the light, the sea, and has thus undoubtedly 
brought about a steady growth in their volume and 
a constant change in their color and texture. Marl 
and clay and green sand and salt and gypsum and 
shale, all have their genesis, all came down to us in 
some way or in some degree, from the aboriginal 
crystalline rocks; but what transformations and 
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