t 134 ] 



characlerize from external appearance only. He 

 divides the whole Regnum Lapideum into three 

 clafTes, under the names of Petr^^ Minera^ and 

 pojjilia^ each being fubdivided into feveral orders, 

 the whole comprehending 54 genera. We muft 

 only give a general account of his clajfical cha- 

 raders, and thofe of the orders \ and enumerate 

 the genera under each, with forpe of the moft dif^ 

 tinguiflied fpecies, 



Clafs I. P E T R iE. Stones. 



Foflil bodies originating from a terrene princU 

 pie by cohefion : 



Simple^ as being deftitute of faline, inflammable 

 and metallic principles, as component parts there- 

 of : 



Fixed^ as not being entirely and intimately f®* 

 luble : and. 



Similar^ as confifting of homogenous component 

 parts. 



Order I. HuMOSi^. Originating from vegeta- 

 ble earth : combuftible, and leaving grofs light 

 ^ afhes.. 



Order 11. Calcarj^. Originating from cal- 

 careous marine animal bodies : becoming light 

 and porous in the fire, and falling into an impal- 

 pable powder. 



Order III. Argii^lace^. Originating from 

 the vifcid fediment, of the fea : fomewhac unduou^ ^ 

 %o the touch, and hardening in the fire. 



Orderly. Arenat^. Originating from the 

 precipitation of rain-water: extremely hard, ftrik- 



ing 



