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previously formed. The same may be said of secondary 

 or shell lime-stone, and several other secondary rocks i 

 and who can say that the several constituent parts of 

 the primitive rocks were not formed, previously to their 

 aggregation ? 



2dly. It may be objected to, on account of the diffe- 

 rence in the several results, that are manifested in 

 rocks of secondary formation, and those of alluvial 

 districts. 



3dly. It may be objected to, on the score, that while 

 secondary formations are the results of a natural ope- 

 ration ; alluvial formations are the results of accidental 

 operations, consequently, differing materially in their 

 essential characters. 



With regard to the first objection, the remarks which 

 I have already advanced in reply, I consider quite 

 sufficient. 



In reply to the second, it may be necessary, in the 

 first place, to observe, that by " the difference in the 

 several results," I have a reference to the various ma- 

 terials that enter into the composition of secondary and 

 alluvial formations, and their different modifications. 

 In this respect, it must be admitted that a very great 

 difference exists, not only in their texture and composi- 

 tion, but in the process of their formation. Yet as 

 great as it is, the difference between alluvial and se- 

 condary formations, is not greater than that between se- 

 condary and primitive. 



To place the subject in a proper light, it may not be 

 amiss to present a slight view of the two formations 



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