ON A NATURAL SYSTEM. 



LXXXIV. Sulphur. 



SULPHUR is an inftance of the mod fimple 

 compofition, confiding of two principles only, 

 acid faturated with phlogifton. 



LXXXV. Petroleum. 



IN petroleum we difcover an union more com* 

 plex ; a final! portion of water combined, by 

 means of an acid, with the principle of inflam- 

 inability. 



LXXXVJ. drnber. 



THE origin of amber is evidently from the ve- 

 getable kingdom, for, befidcs its peculiar acid 

 and oil, we obtain tjie acetous acid by diftilla- 

 tion. The earthy refiduum may be coniideied 

 as a matrix. 



Lxxxvji. Diamond. 



WITH regard to the diamond, 1 have hitherto 

 found no place fo proper for it as this clafs. 

 In a fufficient degree of lire, it is entirely con- 

 fumed, and with an appearance of cloud or 

 rlame; and, in the focus of a burning lens it 

 difcovcrs iigns of a footy matter. 



LXXXVJ 1 1. 



