Muriatic Genus. 7 1 



2. Steatites mixed with Shiftus, or bitu- 

 minous Shiftus. This is blue or black, and 

 rougher to the touch than pure fteatites. 



3. Serpentine mixed with veins or fpots of 

 Shiftus. 



4. Soap-rock mixed with Mica. Cronft. 

 265. Grey, yellow, or greenifh. 



SPECIES V. 

 Compounds of the Muriatic and Siliceous Species. 



i. Serpentine with veins of Quartz or 

 Feltfpar, or Shoerl, 



CHAP. VII. 



Argillaceous Genus. 



SPECIES I, 

 Saturated with Aerial Acid* 



Lac Lun&. 



This fanciful name was heretofore thought 

 to denote a very fine fpecies of calcareous 

 Earth, but Mr. Scbreber has lately fhewn 

 that the Earth to which this name is given, 

 is a very uncommon fpecies of argil i. It 

 is generally found in frnall cakes of the 



V 4 hardnefs 



