i: '6 ] 



I. ROCKS are fteril (loner, produced by cohefion frorti a terrene 

 origin. 



Simple^ without extraneous mixture (of Salt^ Sulphur or M^r- 

 cui>). 



Fixcdy not totally foluble in any memlruum. 



Similar, of panicles confufcdly mixed together, 



1. HuMOSE, from the earthy dcpofition of Vegetables. 

 Comhujlihle y burning into afhes. 



In its minute particles branny^ coarfer and lighter, 



2. Calcareous, from animal earth. 



Penetrable^ and becoming more porous by fire. 



In its minute particles farinaceous, when burnt falling into fa* 

 rinaccous particles, 



3. ApdiLLACEOUS, from a vifcid marine fediment. 

 Hariieningy and becoming harder and more rigid by fire.. 

 la its minute particles lubricous before being burnt. 



4* Arenate, from the precipitation of xtherial fhowers. 



Scintillating^ when ftruck with fteel, and very hard. 



In its minute particles rough, and angular like particles of 

 broken glafs. 



5. Aggregate, and compofed of the 4 preceding fubftances. 



Participating of the conftituent particles of the former ones* 



In its minuted p-irticles varying according to the nature of the 

 m^ierials (i — 4) which compofe it. 



ll. MP^^FRALS are fruitful ftones, produced by crydallization 

 trom a falinc oriain. 



Compound y from rock impregnated with extraneous fubftances, 

 (Salt, ^u'phiir, ar.d Mercury). 



Soluble entirely in their proper menftrnum, (fome calces are 

 diirohibie into earth, but not totally folubie). 



Cryftalliney certainly produced by cryilallization, fbefore they 

 have biicn bu rut's. 



