72 CLASSIFICATION OF ROCKS. 



assuredly, these views had never entered the mind of 

 this inventor of "Transition." 



As an artificial arrangement, it neither facilitates the 

 examination nor the classification of rocks : leading, 

 on the contrary, to a vicious reasoning in a circle : 

 certain rocks being first called " transition," and then 

 used to determine the "transition" class: while, its 

 members never having been defined and limited, it 

 serves any purpose that any one may choose. In the 

 other classes, we can always prevent any abuse of this 

 nature by recurring to their geological positions, which 

 are almost always very decided. But that which 

 seems to be the real history of this invention is, per- 

 haps, the best answer to it. As I have shown, under 

 argillaceous schist, its contriver .had mistaken the up- 

 per red sandstone for the lower ; and hence the infe- 

 rior secondary strata became members of his transition 

 class ; while proceeding to assume the presence of or- 

 ganic remains, and of fragments, as a criterion, some 

 members of the primary also fell into it, with the effect 

 of confounding these two real classes, in addition to 

 all the objections already stated. The confusion which 

 it has thus introduced into geological writings is so 

 great as to render many of them unintelligible ; since 

 scarcely any thing but a re-examination of the rocks 

 described, can enable us to translate them into a 

 meaning. It is indeed fruitless to seek knowledge in 

 the works of those who, use names instead of descrip- 

 tions ; and he who values his time and patience will 

 avoid all those where the term transition occupies a 

 prominent place. 



In now examining the faults of the antient binary 

 division, the first is the confounding of granite and trap 

 with the stratified rocks. With respect to the asserted 

 characters of these, it is not true that, in the pri- 



