14 



mineralogical classification is founded, render that 

 arrangement natural, in one sense, or according 

 to the composition of its objects, it is, in a more 

 important sense, unnatural ; since it separates 

 those wider and more interesting affinities by 

 which rocks are connected with each other and 

 related to the general structure of the earth. As 

 a system, it is, in fact, an artificial one, with the 

 imposing aspect of a natural association ; since it 

 is founded 'on a correspondence of one minute set 

 of appearances, negligent of the larger features, 

 and of the numerous other points of affinity or 

 difference which prevail among the objects of its 

 contemplation. It resembles the artificial arrange- 

 ments of the antient botanists, as compared with 

 the more philosophical views of the moderns in 

 the^r attempts to found one on the characters of 

 natural orders. 



It is of little consequence, for example, whe- 

 ther a bed of hornblende schist alternating with 

 gneiss, contains a few grains of felspar or not. 

 Yet, in a mineralogical system, while the com- 

 pound rock must be placed, as was formerly ob- 



