i8 DISTRICT. 



itfelf. The former contains the Ingredient.*? 

 of flate, in a loofe impure form : and the 

 latter, part of the fame ingredients, in a 

 purer ftate. 



IX. FOSSILS. Blue slates of the 

 firft quahty, for covering houfes, are raifed 

 in different parts of the Dillricl, Slate 

 STONES, for walling, are formed in mod 

 parts of it. 



A fmgular fpecies of freestone Is 

 found near the center of this Diflridt. It 

 has formerly been diflributed over the 

 Weft of Devonlhire, and a great part of 

 Cornwall ; having been ufed moft efpeci- 

 ally for fculptural purpofes, in the Gothic 

 ornaments of churches and other buildings. 

 It appears to have received its immediate 

 formation from fire ; though evidently not 

 the produ(!^ion of a volcano, in the fituation 

 in which it is now found ; being fcattered, 

 at prefent, in detached rocks. It is called 

 " Rooborou^h ftone," from the name of 

 the conimon pafture on which it is more 

 particularly or principally found ^- . Moor- 



STONF, 



* It Is infenfible tfe the marine acid. 



