2*4 ON A NATURAL SYSTEM 



The Indian fpccics agrees in all thing with 

 the European, except its being fofter, and want* 

 ing the volatile fait*, which lad circumftance 

 feems to eilablifh a fpecific difference. Cop;il, 

 commonly fo called, is to be diilinguifhed from 

 the gum rciin of tbat name fold by the apothe- 

 caries. 



$ CLXJI. Origin of PbJogi/llc Sub/lances. 



DIFFERENT opinions are maintained by phU 

 lofophers, refpecling the origin of phlogiilic fub- 

 ftances. Some contend, that thefe bodies arc 

 proper to the foflil kingdom; while others, pro- 

 bably with more reafon, afcribe them to thofe 

 organic fubilanccs which abound in various oi- 

 ly and fat juices, and iirc not fo much ailcclcd 

 by time, as they are gradually changed in the 

 bowels of the earth by neighbouring pyrites and 

 other foilils, until they acquire a bituminous 

 quality. Heterogeneous fubilanccs encloled 

 within them are cxident proofs of original flui- 

 dity. The dittcrcnt degrees of purity of naptha, 

 coagulation performed by time, acids, or other 

 media, and various urcumiliinces bciidcs in the 

 great laboratory of nature, all influence the dcn- 

 fity, colour, clcarnefs and other properties. 



As to ambergrife, Aublet infills, that it is the 

 juice of a tree growing in Guiana, and there 



called 



X 



* I*chman, Chcm. SchnTt. 



