ilUTTONIAN THEORY. 



I 



\ 



\ 



r 



% 



1 



iti 



pofe, that 



long 



fter the 



folid 



of the 



flrata, and during the time of their elevation, 

 the materials of the former were melted by the 

 force of fubterraneous heat, and injeded among 

 the rents and filTares of the rocks already formed. 

 In this manner were iiroduced the veins or dikes 



here circnmflances allow- 



of whinftone 



1 



and 



ed the llream of melted matter to difFufe itfelf 



widely, tabular maffes were formed 



ij 



were afterward 

 fur rounding fir; 



fed 



up 



g 



with th 



above the level of the fe 



and have been fince laid open by the oper 

 of thofe caufes that continually change 

 walle the furface of the land. 



Thefe unftratified rocks are not, 

 the work of the fame period j they differ 

 dently in the date of their formation, and 

 not unufual, to find tabular maffes of one 

 cies of whin. 



1 



wev 



in, interfered by veins of anot 

 Indeed, of all the foffil bodies wh 



fpecies. 



compofe the prefent land, the veins of whin ap- 

 pear to be the moil recently confolidated *. 

 . Porphyry may fo properly be regarded as a 

 variety of whin, diftinguiihed only by involv- 



ing 



yftallized feltfp 



th 



in a geological 



Iketch like the prefent, it is hardly entitled 



a 



fep 



f^ 



article. Like the other kinds of 



F 



whin 



* Note XIV, 



