62 Elements of Mineralogy. 



According to Mr. Bergman's analyfis, 100 

 parts of it contain 80 of filex, 17 of mild 

 magnefia, 2 of argill, and nearly i of iron 

 in a femiphlogifticated ftate. 



II. VARIETY. 



Soap-rock^ Lapis Ollaris* Pot-pone^ Speck/iein 

 of the Germans^ Spanifh Chalk. 2 Margr. 

 14. 



This is of a yellow colour, and fometimes 

 whitifh, and but rarely black : it is alfo 

 fomewhat harder than the former variety, 

 and probably the proportion of argill is 

 fomewhat greater, but in other refpets it 

 perfectly refembles it. The black contains 

 a mineral oil. 



This ftone is eafily worked and turned, in- 

 fomuch that pots and mortars are often made 

 of it. 



Mr. Gerhard remarks, that the Swedifh 

 fpeckftein often effervefces with acids, and 

 contains calcareous Earth, but that of Saxony 

 and Silefia never. The limeftone is merely 

 an accidental mixture. 4 Berlin^ Schrift* 

 300. 



SPECIES III. 



