OF THE ARTH. 465 



fossils in the primary strata, as described in the last 

 chapter; but if there is no proof that the land was 

 also thus occupied, I have shown in that chapter, that 

 the reverse cannot be inferred. If the anthracite of 

 which I there spoke be admitted to be of vegetable 

 origin, there is proof of what were probably terrestrial 

 plants : and if, as is said, vegetable fossils have been 

 found in the primary argillaceous schists, this proof is 

 unquestionable. We have, at least, no right whatever 

 to assume that it was not an inhabited earth in every 

 mode. 



I may now inquire whether, by the same mode of 

 investigation, we can trace a still anterior globe. This, 

 it is plain, can no longer be done by the examination 

 of the nature of whole strata, but it may be attempted 

 by that of their fragments. It might indeed be de- 

 termined by the fragments of clay slate alone which 

 enter into the composition of the primary strata. We 

 are certain, from the imbedded fossils, that our own 

 primary slates were formed out of mud deposited in 

 the sea, and the produce of rocks once existing above 

 the surface. I may extend the same reasoning to 

 those rocks antecedent to the primary strata, which, 

 once elevated above the earth, furnished the fragments 

 in question. These then were the produce of a former 

 sea, the receptacle of the ruins of rocks still more 

 antient, and similarly elevated above the waters to 

 which their waste was conveyed. There is no reason 

 for limiting the application of this argument; for it 

 applies equally to each preceding set of similar phe- 

 nomena, as it does to the latest, which we can almost 

 be said to witness in the present deposits of clay. But 

 as no one deserving the name of a geologist can doubt 

 that the imbedded fragments in the older strata are 

 really the fragments of prior rocks^ whatever may 

 VOL. r. H H 



