*iv PREFACE. 



cies antiently known, denominating all thofe 

 which difcovered any fmgular properties 

 m&j* rapacious and arfenical compounds. 

 Hence the oppofition which the introduction 

 of the new femi-metals, cobalt, nickel, and 

 manganefe ftill meets with among Mine- 

 ralogifts of the antient ftamp. 



However at laft, happily for fcience a few 

 diftingmfhed characters appeared, who, re- 

 jecting all hypothetical delufions, determined, 

 not only to fubmit to no other guide but 

 actual experiment, and its neceflary confe- 

 quences, but alfo to follow it wherever it led 

 them. Of this truly philofophic band, Mr. 

 Margraqf of Berlin led the van, followed by 

 a few others, particularly in Sweden. Dit- 

 coveries now multiplied apace in the hands of 

 a Brandt i S e wab^ Cronfted, Gahn^ and particu- 

 larly Mr. Scbeele, until at laft Mr. Bergman of 

 Upfal, by the folidity of his judgment, the 

 ingenuity and accuracy of his methods, and 

 the multiplicity of his experiments, brought 

 Mineralogy to that degree of perfection at 

 which we at prefent behold it. 



CONTENTS 



