PRINCIPLES OF GEOLOGY. 23 



teach us the great antiquity of that catastrophe, we yet might assure 

 ourselves of it by the contemplation of nature. For when we find the 

 diluvial deposits of clay, pebbles, and bones, covered by shell-marl, silt, 

 peat, and large uprooted trees, accumulations which proceed so slowly in 

 our days, as to be hardly perceived in operation, there is reason to con- 

 clude that a long period separates us from the date of the deluge. And 

 when, in these new accumulations, we find the bones of postdiluvian 

 animals, which have become extinct through accident or persecution, as 

 well as of others, whose successors still exist in the neighbourhood, we 

 may, perhaps, think that little is wanting to complete the evidence 

 of this portion of the physical chronology of the earth. 



Werner, and most of the moderns, consider the phenomena which 

 have been unfolded by geological research, as the effects of causes no 

 longer in action. But Dr. Hutton believed that all the revolutions 

 which have visited the earth, were but the result of the ordinary opera- 

 tions of nature, continued through very long periods of time. He was of 

 opinion that what is now sea, was formerly dry land ; and that by the 

 action of rains and rivers, materials are accumulated on the bed of 

 the sea, to produce the strata of new continents, which by some convul- 

 sion, like many that have happened before, will be uplifted and laid bare, 

 whilst that part of the earth which we inhabit, will be sunk under the 

 new ocean.* To this hypothesis it may be objected, that it ascribes 

 to the ordinary agents of nature effects which appear much beyond their 

 power. General changes in the relative situation of sea and land have 

 been often supposed, but never established by evidence ; for Cuvier's 

 conclusions drawn from the alternations of marine and fresh water for- 

 mations, apply only to limited districts ; and since well-conducted in- 

 quiries into the natural history of antediluvian quadrupeds, have shewn 

 satisfactorily that they lived before the flood over a very large portion 

 of the present continents, we have proof that at the period of the delude, 

 the sea and land did not change their relative situations. 



Eluvie mons est deductus in sequor. 



OVID, METAM. XV. 



