252 THEORY of the EARtH. 



cannot, while in that hard ftate, be made to correfpond fo pre- 

 cifely to each other's fhape as to confolidate the mafs. But if 

 thefe hard bodies fhould be foftened in their fubftance, or 

 brought into a certain degree of fufion, they might be adapted 

 mutually to each other, and thus confolidate the open ftruclure 

 of the mafs. Therefore, to prove the prefent point, we have 

 but to exhibit fpecimens of filiceous and calcareous ftrata which 

 have been evidently confolidated in this manner. 



OF the firft kind, great varieties occur in this country. It is, 

 therefore, needlefs to defcribe thefe particularly. They are the 

 confolidated ftrata of gravel and fand, often containing abun- 

 dance of feld-fpar, and thus ^graduating into granite ; a body, 

 in this refpedl, perfectly fimilar to the more regular ftrata which 

 we now examine. 



THE fecond kind, again, are not fo common in this country, 

 unlefs we confider the {hells and coralline bodies in our lime- 

 ftones, as exhibiting the fame example, which indeed they do. 

 But I have a fpecimen of marble from Spain, which may be 

 defcribed, and which will afford the moft fatisfadlory evidence 

 of the fact in queftion. 



THIS Spanifh marble may be confidered as a fpecies of pud- 

 ding-ftone, being formed of calcareous gravel ; a fpecies of 

 .marble which, from Mr BOWLES'S Natural Hiftory, appears to 

 be very common in Spain. The gravel of which this marble 

 is compofed, confifts of fragments of other marbles of different 

 kinds. Among thefe, are different fpecies of oolites marble, 

 fome fhell marbles, and fome compofed of a chalky fubftance, 

 or of undiflinguifhable parts. But it appears, that all thefe 

 different marbles had been confolidated or made hard, then 

 broken into fragments, rolled and worn by attrition, and thus 

 collected together, along with fome fand or fmall filiceous bo- 

 dies, into one mafs. Lqftly, This compound body is confoli- 

 dated in fuch a manner as to give the moft diftinft evidence, 



that 



