232 Professor Necker on Mineralogy considered 



only to point out the more general leading principles of our 

 inquiries. 



Sect. III. — Principles of classification. 



§ 37. Mohs is one of the first mineralogists who has treated 

 mineralogy as a branch of Natural History. If by setting 

 aside some of the most important considerations and characters, 

 the chemical ones, he has been prevented from attaining the 

 natural method, it is to be observed, that he at least made an 

 attempt to obtain this object ; and what is worthy of remark, 

 he proceeded in his classification according to the method of ge- 

 neral comparison, introduced into botany by Adanson, as the first 

 step towards a natural and philosophical arrangement of plants. 

 He, in imitation of Adanson, first formed as many series or ar- 

 tificial systems as he had characters, and then disposed in the 

 same orders those minerals which he had found to come near 

 each other in the greater number of those series or systems. 



But here the vices which have been pointed out by De Can- 

 dolle, in what he has called the method of general comparison, 

 were fully exemplified, and though Mohs has in some cases, as 

 we have mentioned before, hinted at some very natural orders 

 or families, the greatest part of his divisions shows his want of 

 acquaintance with the notion of the subordination of characters ; 

 and by the omission of the chemical properties, his system 

 has become more than any other liable to the strong objections 

 urged by De CandoUe against all the methods of general com- 

 parison, viz. that of never embracing all the characters and all 

 the points of view under which those characters may be consi- 

 dered, and that of attributing to all the characters the same 

 degree of importance, and to all the points of view the same 

 degree of interest. 



§ 38. We are now to point out in a very summary way the 



chief principles, which have guided us in our attempt to iru 



troduce into mineralogy a method resting on the subordination 



of characters. We shall not at present insist on what is but an 



application of the rules laid down in the preceding section, as 



the following sketch of the first divisions of the classification 



will afford practical examples of what would be here mentioned 



theoretically. But it is necessary to bring under the notice of 



3 



