12 INTRODUCTION. . 16. 



The necessity of a systematic nomenclature in Natural 

 History needs no demonstration. Fundament um Botanices 

 duplex cst: Dispositio ct Denominatio. LINN. Phil. Bot. 

 151. The systematical nomenclature is the base upon 

 which the existence and the progress of the science is 

 founded, which, without it, must fall into confusion. This 

 is more obvious, indeed, in Zoology and Botany, than in 

 Mineralogy, yet by no means legs true in this part of 

 Natural History, as is sufficiently proved by long conti- 

 nued experience. 



No systematical nomenclature has hitherto, existed in 

 Mineralogy ; and even the fragments of it* to be met with 

 here and there, dp not deserve oui" attention, because they 

 refer to systems foreign to Natural History. 



Trivial names* are not fit for any scientific use, but they 

 are very convenient for common usage, particularly if they 

 are well chosen. 



. 16. CHARACTERISTIC. 



The Characteristic furnishes us with the peculiar 

 terms or marks, by which we are able to distinguish 

 objects from each other, in so far as they are com- 

 prehended in the ideas established by the Theory 

 of the System. The Characteristic is peculiar to 

 the Determinative part %f Natural History (. 11.). 



The Characteristic presupposes the general notions or 

 ideas of Natural History to have been developed and appli- 

 ed to the data of observation, and therefore is not the 

 source of these ideas, nor of any other. The natural-his- 

 torical properties, or those assemblages of them, by which 

 we can distinguish the different species of one genus, the 

 different genera of one order, the different orders of one 



* What Linnceus calls trivial names, will be explained in 

 its proper place. 



