6J8 



UN GEOLOGY. 



But this is to sjippose the earth of a far higher antiquity, and to have heeu 

 the subject of more numerous general deluges, and inversions of sea and 

 land, than are called for by the Wernerian system, or appear reconcileable 

 with the Mosaic narrative. M. Cuvier apprehends, indeed, that such ca- 

 tastrophes may have occurred five or six times in succession, at a distance 

 of four, five, or six thousand years from each other ; and that even the 

 chalk formation found in the basin of Paris originated in a revolution of this 

 kind that occurred antecedently to that which is usually regarded as the 

 flood of Noah. And, following up this idea, he conceives, towards the 

 close of his Introductory Theory of the earth, that if the science of fossil 

 organic productions could be carried to a much higher degree of perfection, 

 we should be able to obtain far fuller information upon this subject ; " and 

 man, to tvhom only a short space of time is allotted upon the earth, would 

 have the glory of restoring tJte history of thousands of ages whichpreceded 

 tlie existence of the human raqe^ and of thousands of animals that never 

 were contemporaneous with bis species." 



LECTURE VIL 



ON GEOLOOy. 

 (The subject continued.) 



In our last study I attempted a brief sketch of the chief phaenomena tha^ 

 occur to the eye of the geologist upon a survey of the solid crust of the 

 earth, as far as he is able to penetrate into it. The conclusion to which 

 such phasnomena lead us is the following : that the rudimental materials 

 of the globe, to the utmost depth we are able to trace them, existed at its 

 earliest period, in one confused and liquid mass ; that they were aflerwards 

 separated and arranged by a progressive series of operations, and an uni- 

 form system of laws, the more obvious of which appear to be those of 

 gravity and crystallization ; and that they have since been convulsed and 

 dislocated by some dreadful commotion and inundation that have extended 

 to every region, and again thrown a great part of the organic and inor- 

 ganic creation into a promiscuous jumble. 



Now the only two causes that can enter into the mind of man as being 

 competent to the fluidity that appears at first to have existed throughout 

 the whole crust of the earth are fire, or a peculiar solvent. But, if a 

 solvent, that solvent must have been water : for there is no other liquid 

 in nature in sufficient abundance to act the part of a solvent upon a scale 

 so extensive. 



And hence our inquiries into this subject become in some degree limited, 

 and are chiefly confined to what have been called the Plutonic and the 

 Neptunian hypotheses ; the origin of the world in its present state from 

 igneous fusion, and from aqueous solution. Both these theories are of a 

 very early date, and both of them have been agitated in ancient as well as 

 in modern times with a considerable degree of warmth as well as of plau- 

 sible argument. 



Among the ancients, Heraclitus seems to have headed the advocates 

 for the former theory, and Thales, or rather Epicurus, the supporters of 

 ihe latter. In what may be regarded as modern times, Hooke may, jK^r- 



