VIEWS ON MINERAL SPECIES. 



THE death of James Dwight Dana, following only 

 three years after the publication of the sixth edition 

 of his great "System of Mineralogy" calls to mind the 

 remarkable changes which have transformed mineralogical 

 science since the appearance of the first edition of that 

 work in 1837. 



It is my purpose in the present article to call attention 

 only to the change of views regarding classification and 

 nomenclature which has occurred during the intervening 

 period, and to criticise the position in which mineralogists 

 now stand in the matter of mineral species, their definition, 

 and their relationships. 



Professor J. D. Dana was attracted to the study of 

 mineralogy early in life, and died at the age of eighty-two ; 

 he was always the most prominent systematist in this science, 

 and from his intimate acquaintance with geology and zoology 

 was singularly fitted to hold wide and comprehensive views 

 upon such subjects as the definition and systematic arrange- 

 ment of species ; he reformed the nomenclature of 

 mineralogy, and constructed a system from the ruins of its 

 unsuccessful predecessors which had prevailed in the early 

 part of the century ; consequently his book in its various 

 editions may almost be regarded as an authoritative record 

 of the successive steps taken by Systematic Mineralogy 

 during more than half a century, and reflects the varying 

 aspects which that ever-shifting subject has presented at 

 different times. The sixth edition, though largely re- 

 written by his distinguished son, is carried out strictly on 

 the lines laid down in the preceding editions. 



THE NATURAL HISTORICAL SYSTEM OF CLASSIFICATION. 

 It is difficult now to believe that in the first and second 

 editions the author warmly espoused the so-called Natural 

 System of Werner and Mohs. According to that system, 

 the only characters of minerals which possess any import- 

 ance for purposes of classification are the external 



