THEORY OF THE EARTH. 37 



perature of the globe is either diminishing or in- 

 creasing ; none of these causes could have over- 

 turned our strata; enveloped in ice large ani- 

 mals, with their flesh and skin ; laid dry marine 

 testacea, the shells of which are, at the present 

 day, as well preserved as if they had been drawn 

 up alive from the sea ; and, lastly, destroyed nu- 

 merous species, and even entire genera. 



These considerations have struck most natura- 

 lists ; and among those who have endeavoured to 

 explain the present state of the globe, hardly any 

 one has attributed it entirely to the agency of slow 

 causes, still less to causes operating under our 

 eyes. The necessity to which they are thus re- 

 duced, of seeking for causes different from those 

 which we see acting at the present day, is the very 

 circumstance that has forced them to make so 

 many extraordinary suppositions, and to lose 

 themselves in so many erroneous and contradic- 

 tory speculations, that the very name of their 

 science, as I have elsewhere remarked, has long 

 been a subject of ridicule to prejudiced persons, 

 who have only looked to the systems which it has 

 been the means of hatching, and have forgotten 

 the extensive and important series of authentic 

 facts which it has brought to light #. 



* When I formerly mentioned this circumstance of the 

 science of geology having become ridiculous, I only expressed 

 a fact, to the truth of which every day bears witness ; but in 



