Ch. XIV.] OF THE STRATIFIED ROCKS. 295 



secondary strata is thought to be substantiated, is not free 

 from objections. The same difficulties may be equally advanced 

 on the present occasion ; for, if the prevailing theory fails to 

 show that the primary slates were once in the condition of 

 sedimentary deposits if it fails to demonstrate that the 

 former, at the period of their formation, did perfectly resem- 

 ble the latter then it does not follow that the present nature 

 of the crystalline slates has resulted from any superinduced 

 action or metamorphosis ; on the contrary, their existing 

 state may be original. In the previous examination of this 

 question, one important consideration which has been ad- 

 vanced in support of the crystalline slates being altered rocks, 

 was omitted : before proceeding, therefore, to discuss the 

 capability of caloric to effect such changes, the subject of this 

 omission must engage our attention. 



In tracing the nature and position of the stratified rocks 

 which surround granite, from distant points up to the central 

 unstratified mass, it has been remarked, that the fossiliferous 

 strata appear to pass gradually into the primary slates which 

 are in immediate contact with the granite. And, since these 

 strata belong to various geological epochs, in different coun- 

 tries, it has been concluded, that the primary slates are 

 altered rocks belonging to the same periods as the adjoining 

 sedimentary deposits. 



This is clearly and distinctly propounded ; and is an argu- 

 ment not to be easily opposed, for it is based on the observa- 

 tions of the most experienced geologists ; and it can, therefore, 

 be only disputed by questioning the accuracy of their con- 

 clusions. This is a painful alternative, and more especially 

 as we cannot appeal to Nature, and positively demonstrate 

 the fallacy of the data from which they have formed their 

 deductions ; but can only advance our views of the subject, 

 which may, very probably, prove equally fallacious. To differ 

 from the best authorities on such grounds, may be deemed 

 an unpardonable proceeding ; but, as these distinguished phi- 

 losophers are lovers of truth, we feel assured that they will 



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