Vlll PREFACE. 



The ore of Zink, or Lapis Calaminaris, 

 is found in vast quantities in the counties 

 of Somerset and Flint ; while black lead 

 or wadd, a substance searce known in 

 other kingdoms, abounds in the moun- 

 tains of Cumberland. 



To the Swedish Petroleum, we may 

 oppose the Weil at Pitchford, and that 

 of St. Catherines new Edinburgh. Our 

 amber and our jet, together with our in- 

 exhaustible strata of coal found in so 

 many parts of this kingdom, will, in the 

 article of bitumens, give us the superiority 

 over these so much boasted productions 

 of Sweden. 



To avoid a tedious enumeration, we 

 shall only mention our wonderful mines 

 of rock salt; our allum and our vitriol 

 works ; our various marbles, alabasters, 

 and stones ; our most excellent clays and 

 earths ;* all which articles, and many 



* If the inquisitive reader is desirous of a farther 

 account of the number and excellence of our subter- 

 raneous productions, we refer him to the learned Dr. 

 Woodward's Catalogue of the English Fossib, London 

 1729, particularly to' p. 5. 



