56 THEORY OF THE EARTH. 



have overthrown our strata; enclosed great qua- 

 drupeds with their flesh and skin in ice; laid dry 

 sea-shells in as perfect preservation as if just drawn 

 up alive from the bottom of the ocean; or utterly 

 destroyed many species, and even entire genera, 

 of testaceous animals. 



These considerations have presented themselves 

 to most naturalists: And, among those who have 

 endeavoured to explain the present state of the 

 glohe, hardly any one has attributed the entire 

 changes it has undergone to slowly operating 

 causes, and still less to causes which continue to 

 act, as it were, under our observation. The ne- 

 cessity to which they were thus reduced, of seek- 

 ing for causes different from those which we still 

 observe in activity, is the very thing which has 

 forced them to make so many extraordinary sup- 

 positions, and to lose themselves in so many erro- 

 neous and contradictory speculations, that the very 

 name of their science, as I have elsewhere said, 

 has become ridiculous in the opinion of prejudiced 

 persons, who only see in it the systems which it 

 has exploded, and forget the extensive and impor- 

 tant series of facts which it has brought to light 

 and established.* 



*When I formerly mentioned this circumstance, of the science of 

 geology having become ridiculous, I only expressed a well-known 

 truth, without presuming to give my own opinion, as some respecta- 

 ble geologists seem to have believed. If their mistake arose from my 

 expressions having been rather equivocal, I take this opportunity of 

 explaining my meaning. 



