TRAP ROCKS. 163 



State, and inclined positions in which we now tind them, is 

 iiostile to every thing like ftiir induction from facts and pro- 

 positions conceded on all hands. Then to assign an ade- 

 quatc cause for the effects discoverable in the disjointed and 

 scattered condition of the earth's crust, we are driven hy 

 necessity to liave recourse to the tiieory of Dr. Hutton,* 

 which, although we may not choose to adopt it in its lull 

 extent, alone affords a rational solution of the difficidties 

 that embarrass the subject. While I acknowledge that his 

 theory of the consolidation of the stiata by means of heat 

 at the bottom of the sea, appears to be altogetlier unneces- 

 sary and beset with insuperal)le difficulties, I am compelled 

 by the want of any other adequate agent to assent to his 

 doctrine that the changes between oceans and continents arc 

 due to tlie expansive ])ower of heat from below. Earth- 

 quakes are doubtless tlie more languid efforts of the same 

 power ; and when during these, we behold the surface of the 

 earth tossing like a sea, while mountains are raised or districts 

 of country swallowed up, wc may judge of what it is capable 

 of effecting, when roused into full activity. In earthquakes 

 as well as volcanoes, electiicity acts an efficient l)ut subor- 

 dinate part ; for during an eruption, vivid flashes of liglit- 

 ning issue from the clouds of pumice and ashes sent up, 

 and shocks of earthquakes are frequent and violent. Moun- 

 tains are nothing but dislocated portions of the eartli's crust, 

 anrl nnist thciefore owe their formation to the same general 

 cause that effected the other parts of the giand revolution. 

 Else how could granite, the lowest of the known formations, 



• The changes that have taken place on llie earth's surface, were, it seems, 

 at a very early perioil ascribed by Xanthus to earthquakes and subterraneous 

 6res, which, at the delude, elevated some portions of the bed of the sea, as 

 well as depressed others, and produced (lie iiic(|ualitic.s of tlie solid parts of 

 the globe. This o]iinion was afterwards, in 1692, in substance adopted by an 

 English geologist of the name of Hay ; and alsn iti 1740 by an Italian called 

 Laz^ro Moro. 'I'iieir writings may have suggested to Dr. Hutton a distin- 

 guishing feature of his theory : but none of them appear to have suspected 

 what he has, I think, established, a succession of continents which he calls a 

 succevsiun of worlds. 



