50 ILLUSTRATIONS OF THE 



the foftnefs of the rock, but many of its com, 

 plete induration. 



The fame phenomenon which is thus exem- 

 plified on a great fcale in the bowels of the 

 earth, is often moll beautifully exhibited in fin- 

 gle fpecimens of ftone, and is accompanied with 

 this remarkable circumftance, that the inte^ 

 gr'ity of the ftone is not deftroyed by the fhifts, 

 whatever wounds had been made in it being I \ 

 healed, and the parts firmly re-united to one ano- I .1 



ther 



gular 



] 



^ 



3 

 t 



t 



a 



c, 

 r( 



n 



43. Though fuch marks of violence as have 

 been now enumerated are common in fome de- 

 gree to all the ftrata, they abound moft among I \x 

 the primary, and point out thefe as the part 

 of our globe which has been expofed to the I j 

 greateft viciffitudes. At their jun6lion with the I ^i 

 fecondary, or where they emerge, as it were, 

 from under the latter, phenomena occur, which 

 mark fome of thofe viciflStudes with aflionifiiing 

 precifion ; phenomena of which the nature was I j 

 firfl accurately explored, and the confequences 

 fully deduced, by the geologift whofe fyllem I I \ 

 am endeavouring to explain. He obferved, 

 in feveral inftances, that where the primary 

 fchifl;us rifes in beds almoft vertical, it is co- 

 vered by horizontal layers of fecondary fand- | ^^ 

 ftone, which laft are penetrated by the irre- 





ge: 



rac 

 wit 



^\\ 



Note si. 



