E W 3 



the touch, friable and {tains the fingers flightiy, 

 difFufible in water and duftile ; efTervefces a lit- 

 tle with acids. Anal. Carbonate of argill and 

 filex. 



d. Porcelain Clay % white, and greyifh, foft to the 

 touch ; when mixed with and moulded into vef- 

 fels, and expofed to a flrong heat, affumes the ap- 

 pearance of a. femi-tranfparent glafs ; firikes hre 

 with fteel ; is not acled upon by acids ; and pre- 

 ferves it's fhape. Anal. Argill 60. Silex 20. 

 Wedgewood. 



e. Lithomarga, Mountain foap, friable, indu- 

 rated, amorphous ; texture frequently poiilhed, 

 flaty, conchoidal ; colour white, yellowilh or 

 reddifh white; emits a phofphorefcent light, when 

 rubbed in the dark with a pin ; foft and foapy to 

 the touch, abforbs water rapidly, and retains it 

 for a long time. Anal. Argill 11. Silex 60. 

 Carbonate of lime 5,7. Carbonate of magnefia 

 0,5. Oxyde of iron 4,7. Air and water 18. 

 Bergman. 



f. Fullers Earth, greenifh white colour, or 

 greyifh white, receives a polifh from fri&ion ; 

 does not adhere to the tongue ; feels fomewhat 

 greafy; falls into powder in water. Anal. Ar- 

 gill 0,25. Silex 0,51. Carbonate of lime 0,03. 

 Carbonate of magnefia 0,007. Oxyde of iron 

 0,03. Moifture and air O3I5. Bergman. 



g. Bole, particles very fmall, and cohere 



Q flightiy ; 



