

f*50 A SYSTEM OF 



this work ; they are here only defcribed, fuch as 

 they are naturally found, viz. entangled in certain 

 heterogeneous bodies, of which they require but 

 very little for their faturation. 



SECT. CXLIV. 



The THIRD CLASS. 



MINERAL INFLAMMABLE SUBSTANCES, 

 Pblogifia Miner alia. 



To this clafs belong all thofe fubterraneous bo- 

 dies that are diflbluble in oils, but not in water, 

 which they repel 5 catch flame in the fire; and are 

 electrical. 



It is difficult to determine what conflitutes the 

 difference between the purer forts of this clafs, 

 fince they all muft be tried by fire, in which they 

 all yield the fame product-, but thofe which in 

 the fire mew their differences by containing diffe- 

 rent fubflances, are here confidered as being mixed 

 with heterogeneous bodies : that fmall quantity of 

 earthy fubftance, which all phlogifta leave behind 

 in the fire, is, however, not attended to, 



SECT. CXLV. 



I. Amber grife, Ambra grifea* 



Is commonly reckoned to belong to the mi- 

 neral kingdom, although it is faid to have doubt- 

 ful marks of its origin. 



a. It has an agreeable fmell, chicflv when 

 burnt. 



b. It is confumed in an open fire. 



c. It 



