ALLUVIA. 627 



been considered in another place. Most of the 

 secondary rocks indeed, and, perhaps, not a few 

 of the primary, may be supposed to have had a 

 similar origin ; but these are questions appertain- 

 ing to geology. 



Respecting the texture and composition of 

 these rocks, it is scarcely possible to say any thing 

 which would not be a repetition of what has been 

 said in treating of the loose alluvia, or which may 

 not be as easily deduced from the preceding ob- 

 servations. The more minute peculiarities will 

 find a more proper place in the Synopsis. 



Like the loose alluvia, they may also contain 

 imbedded minerals ; and the diamond has thus 

 been found forming part of a conglomerate al- 

 luvial rock. Organic remains also occur in them ; 

 and some of the instances, such as that of the 

 West Indies so well known as containing human 

 skeletons, are particularly interesting ; as, from 

 confounding them with earlier rocks of similar 

 character, the most serious geological errors 

 might arise. 



s s 2 



