98 A SYSTEM OF 



d. Blue, is very common in Sweden, 

 in the provinces bordering upon 

 the Baltic. 



e. White, is found in the woody parts 

 of Sodermanland, Dalarne, and 

 of other provinces. It is often 

 found in a flaty form, with fine 

 fand between its ftrata. It is not; 

 eafy to be baked in the fire : when 

 it is burnt, it is of a pale red colour, 

 and is more fufible than the pre- 

 ceding ones. 



/. Fermenting clay, Argilla intu~ 

 mefcens. 



This is very like the preceding 

 (^), as to the external appearance, 

 and other qualities ; but when they 

 are both found in the fame place, 

 which is not uncommon in feveral 

 of our mine countries, they feem 

 to be different in regard to the fer- 

 menting quality of this variety. 

 This fermentation cannot be the 

 efFecl: of the fand mixed with it, 

 becaufe fand is found in them 

 both : and befides, this kind fer- 

 ments in the fame manner when it 

 is mixed with gravel or flones; 

 and then it ferments later in the 

 fpring than the other, fince by the 

 flones, perhaps, the frofl is longer 

 retained in it. 

 ?. Mixed with lime, fee Marle 3 Seclio£ 



SECT, 



