Mineralogy, according to the Principles of Professor MOHS. 299 



the foundation of scientific Mineralogy, and it must, on that ac- 

 count, be reduced to constant and philosophical principles, and 

 not be left at the mercy of chance and empiricism. 



If we consider the progress of mineralogical systems from 

 the first attempts of LINNJBKJS to the present day, it appears 

 that, while the general scientific form of the systems was insen- 

 sibly lost, while essential degrees of classification were aban- 

 doned, while even the characteristic marks between substances 

 resembling each other were deemed superfluous * ; the determi- 

 nation of the species continued gradually to approach nearer to 

 perfection. The system of LINNAEUS, with its ternary distribu- 

 tion, containing three classes, each of which comprises three or- 

 ders, and the system of WALLERIUS, with its quaternary distri- 

 bution, each of his four classes comprehending four orders, gave 

 way to the systems of CRONSTEDT and WERNER, in which the 

 characteristic differences, and the order, as a unity of classifica- 

 tion, disappeared, and to the system of HAUY, in which distinc- 

 tive characters are introduced, not for discriminating a newly 

 observed individual from all the rest, but for producing a con- 

 trast between it and one or a few others, mentioned by name, 

 and which, moreover, at least in one, and the most numerous of 

 its classes, contains neither orders nor genera. 



However valuable the labours of WERNER may have been in 

 clearing the mineral system of compound rocks formerly held, along 

 with the simple minerals, to be proper objects of mineralogy, yet 

 it is particularly to the accurate investigations of the forms by 

 HAUY, resting, in part, upon ROME' DE L'!SLE'S observations, 

 that we are indebted for a more correct determination of the 

 species contained in his system. This greater degree of correct- 



* LINNAEUS, when speaking of the system and principles of CRONSTEDT, says 

 " J)efinit\ow8 characteristicas inutiles judicat : sufficere npsse." Syst. Nat, 



