PREFACE. v 



enquires which appear to me to belong to an- 

 other branch of the fcience of foffils, viz. 

 Natural Hiftory, but rather to determine the 

 characters by which foffils are invariably and 

 permanently diftinguifhed from each other in 

 all times and places. In a word, rather to 

 define the fpecies than defcribe the indivi- 

 dual; even among thefe permanent charac- 

 ters I have, for the fake of brevity, omitted 

 all, except the moft obvious, a compleat de- 

 tail of them being in my opinion fitter for a 

 treatife f Chymiftry than of Mineralogy. 

 The merit of this latter feeming to me to 

 confift in prefenting fuch criteria as may 

 enable us to diftinguifh Minerals in the 

 fhorteft, eafieft, and fureft manner ; fo that 

 we may always apply the lame names to the 

 fame fubftances, and being confident of 

 fpeaking the fame language, may always un- 

 derftand each other. What confufion hath 

 heretofore arifen from the ambiguity of 

 names is well known, and will, I fear, render 

 many very mterefting refearches, even of mo- 

 dern date, intirely ufelefs. Among thefe I 

 ihall only mention thofe of the celebrated 

 Canon Recupero^ who for many years, and 

 with immenfe pains, has ftudied and de- 

 fcribed the Minerals in the neighbourhood pf 

 Mount &tna f but committed fuch miftakes 

 in their denomination as will, according to 

 the remark of that excellent Mineralogift 

 A 4 Mr* 



