62 



theless with propriety be admitted as an artificial 

 division ; the hypothetical opinions on which it 

 was originally founded, being such as, probably, 

 to have now few advocates even among those who 

 have adopted it. 



In trying it by this test, it is plain that it 

 cannot facilitate the classification and nomencla- 

 ture of species; as the same substances which 

 occur in the primary, must necessarily also occur 

 in the transition class. They are indeed acknow- 

 ledged thus to occur, and, for want of real dis- 

 tinctions, are generally denoted by the use of the 

 hypothetical term, often applied in a manner 

 purely arbitrary. Since also it has been shewn 

 that this division cannot be distinguished by any 

 geological characters, it can evidently be of no 

 use in geological investigation, or in classing the 

 phenomena which may be observed. On the 

 contrary, it is productive of confusion, and tends 

 to mislead observers ; as it is only by some pre- 

 sumed mineral distinction of the species, that a 

 rock can be referred to this imaginary division. 

 Hence, the nature of the species alone forms the 

 ground of judgment ; not only for the character 



