290 



ILLUSTRATIONS OF THE 



evidently concreted from fuiion, in which the 

 marine foflil bodies, originally, as he fuppo- 

 fes, contained in the ftrata, were perfectly di^ 

 flinguifhable, though varioully disfigured*. It 

 may be, that in this, as in the foregoing exam- 

 ples, it was not real bafaltes, or real lava, 'which 



1 



contained the (liells, but the conterminal rock; 

 but, fuppofmg it to be as Mr Strange reprefents 

 it, there appears to be no inconfiftency between 

 the phenomenon, and the igneous origin of the 

 rock in which the Ihells were included. Here, 

 however, it lliould be remarked, that the pre- 

 fence of great preflTure, to prevent the conver- 

 lion of the fliells into quicklime, feems abfolute- 



* 



]y neceffary ; and that the phenomenon of thefe 

 bafaltic petrifad:ions, requires the application of 

 heat to have been deep under the furface of the 

 earth. 



255. The phenomena we have been conlider- 

 ing, have been feleded as the moil unfavourable 

 to the igneous origin of bafaltic rocks ; and we 



ha\' 



fee 



that 



hen duly examined, they 



not at ail 



onfift 



We 



take a view of fome appearances, that feem quite 



irreconcilable 

 thefe rocks. 



th th 



aq 



formation of 



x' 



Where 



* Phil.Tranf. 1775, p. 25 



*^ 



