OF FOSSILS. 



shrax *, aluminous fchiftus, aluminous ore of 

 La Tolfa, and many others, contain fome extra- 

 neous earthy matter, and in confiderable quan- 

 tity. 



xciv. Third Genus. 



IN the third genus, the metallic nature is pre- 

 dominant. It has been long obfcrved, that 

 ibmc metals ailed a difpofhion to aflociate with 

 each other; ib that if one is discovered, it may 

 be properly conjectured that the other is not ve- 

 ry tar diilant. Relations fuch as thefe, as arc ob- 

 vious in this genus, arc worthy attention and 

 enquiry, as they prciniJc no Imall advantage to 

 the inhabitants of mountainous countries. 



xcv. Fourth Genus. 



IN the fourth genus we meet with variou3 

 mixtures of fofllls, of which this ruling principle 

 belongs to the lail clafs. 



V 



$ xcvi. DlJllnCl and mixed Particles of FcJJih. 



To this appendix likewife, the diftinft and 

 mixed particles of foil i Is may conveniently be 

 referred, inferting them under their proper ge- 

 nera, according to circuiullances. Such, for 



example 



Pit coal. 



