25 



THE EARTH FORMED GEOLOGICAL 

 CHANGES. 



IN our version of the romance of nature, we now descend 

 from the consideration of orb- filled space and the character of 

 the universal elements, to trace the- history of our own globe. 

 We shall see that it falls into connexion in an interesting 

 manner with the primary order of things indicated by La- 

 place's Hypothesis. 



The nature of the materials of the externe or crust of our 

 globe, is known to a greater depth than might be supposed, 

 in consequence of the relation of position of its various 

 masses. C'onfused as these at first appear, an order of ar- 

 rangement, connected with time, has been detected in them 

 by the labours of modern geologists. It is found that a cer- 

 tain kind of rock, below which there is never, in ordinary 

 circumstances, any other kind, is of crystaline character. 

 Sometimes elevated in naked mountain masses, sometimes 

 found only at great depths below other rocks of a different 

 kind, Granite (for such is its name) appears as the basis 

 rock of the earth's crust ; the form into which the once 

 fluid matter of our planet was primarily resolved, although, 

 in many instances, subjected, under heat, to new move- 

 ments at times' long subsequent. The crystals of granite 

 are of distinct substances quartz, felspar, mica, and horn- 

 blende (each of which is, again, a combination of a cer- 

 tain number of the simple or elementary substances) : two 



