INTRODUCTION. 



Of the Palcetiological Sciences. 



WE now approach the last class of sciences 

 which enter into the design of the present 

 work ; and of these, Geology is the representative, 

 whose history we shall therefore briefly follow. By 

 the class of sciences to which I have referred it, I 

 mean to point out those researches in which the 

 object is, to ascend from the present state of things 

 to a more ancient condition, from which the present 

 is derived by intelligible causes. 



The sciences which treat of causes have some- 

 times been termed cetiological, from atria, a cause : 

 but this term would not sufficiently describe the 

 speculations of which we now speak; since it might 

 include sciences which treat of permanent causality, 

 like Mechanics, as well as inquiries concerning pro- 

 gressive causation. The investigations which I now 

 wish to group together, deal, not only with the pos- 

 sible, but with the actual past; and a portion of 

 that science on which we are about to enter, Geo- 

 logy, has properly been termed Palaeontology r , since' 

 it treats of beings which formerly existed 1 . Hence, 

 combining these two notions' 2 , Palwtiology appears 

 to be a term not inappropriate, to describe those 



i/ra. 2 FlaXcu, aiT/a. 



