Geological Obfervations. 373 



APPENDIX III. 



Geological Obfervations. 

 Mountains: 



pLEVATIONS, confifting chiefly of day, 

 ** fand or gravel, are called Hills 9 thofc 

 that confift chiefly of ftone are by mine- 

 ralogifts called Mountains. As they are the 

 chief repofitories of minerals, and particu- 

 larly of metallic ores, I fhall here relate the 

 moft interefting obfervations relative to them 

 that have occurred to me, or that have been 

 made by others. 



Mountains may be confidered either with 

 a view to their antiquity and origin, their 

 height, or their ftrudure. 



Of the Antiquity and Origin of Mountains. 



In this point of view mountains are di- 

 vided into primxvaly that is, of equal date 

 with the formation of the globe, and fecon- 

 dary, or alluvial; fome add even tertiary ; 

 but this diftin&ion I think fuperfluous. 



Among the primaeval, thofe that confift of 



granite hold the firft place. The higheft 



mountains, and moft extenfive ridges in every 



B b 3 part 



