Dr. Boase in reply to Mr. Hopkins. 15 



in their original position, in mass or insulated between loose 

 earthy beds, — in as much, I say, as all these exhibit joints or 

 lines of structure, I think that I am justified in regarding 

 this condition as a species of crystallization, — the inseparable 

 consequence of the particles of an originally unconsolidated 

 mass liaving been completely subjected to the operation of 

 cohesive attraction. 



If Mr. Hopkins's hypothesis requires it to be otherwise, it 

 is incumbent on him to adduce facts in support of his opinion. 

 Perhaps, he will not dispute this position, but content himself 

 with maintaining that the rocks, when elevated, were not in a 

 solid state. I shall, however, have no difficulty in establish- 

 ing the contrary ; for there is ample evidence of rocks, before 

 dislocation and elevation, having been solidified. 



But, says Mr. Hopkins, "in my investigation it is unneces- 

 sary to suppose any but the lowest degree of solidification in 

 the elevated mass ; and therefore it is^ manifestly quite inad- 

 missible to assume that it could not be dislocated by an eleva- 

 tory force before its jointed structure had become sufficiently 

 developed to determine the directions of dislocation." I do 

 not assume that an unconsolidated mass cannot have been 

 elevated or depressed ; because it is evident, that recent se- 

 dimentary deposits must be acted on, according to the move- 

 ments of the older solid rocks on which they repose ; but I do 

 assert that rocks over extensive regions in every part of the 

 globe, (and only one instance would suffice for the argument,) 

 when thus acted on, were not in the lowest, nor in any inter- 

 mediate degree of the process of induration, but were per- 

 fectly consolidated. 



For instance, various series of rocks, including those of 

 more than one epoch, have accumulated, during the lapse of 

 ages, from the comminuted debris, angular and water-worn 

 fragments of older rocks, in the hollows of which they have 

 been deposited; these derivative rocks now exhibit faults, 

 veins, and other indications which Mr. Hopkins ascribes to 

 elevatory movements. Now it is of no consequence whether 

 these upper derivative rocks were solid or not ; but it is evi- 

 dent that the parent fundamental rocks must have been per- 

 fectly solid or they could not have furnished the pebbles, which 

 very commonly consist of quartzose and other siliceous sub- 

 stances, not only belonging to older sedimentary formations 

 but also to igneous rocks which cannot be supposed to have 

 been reduced to a state of detritus by aqueous action until 

 they were actually so/zW. It may also be remarked, that it i 

 generally admitted that movements, such as have taken pi 

 in former days, are now and will be hereafter in operation: 



