246 Ford — Growth of Mineralogy, 1818 to 1918. 



betical one throughout. Subsequent editions appeared 

 in 1844, 1852 and 1857. 



James Dwight Dana was graduated from Yale College 

 in 1833 at the age of twenty. Four years later (1837) he 

 published i ' The System of Mineralogy, ' ' a volume of 580 

 pages. The appearance of this book was an event of 

 surpassing importance in the development of the science. 

 The book, of course, depended largely upon the previous 

 works of Haiiy, Mohs, Naumann and other European 

 mineralogists, but was in no sense merely a compilation 

 from them. Dana, particularly in his discussion of 

 mathematical crystallography, showed much original 

 thought. He also proved his originality by proposing 

 and using an elaborate system of classification patterned 

 after those already in use in the sciences of botany and 

 zoology. He later became convinced of the undesira- 

 bility of this method of classification and abandoned it 

 entirely in the fourth edition of the System, published in 

 1854, substituting for it the chemical classification which, 

 in its essential features, is in general use to-day. The 

 System of Mineralogy started in this way in 1837, has 

 continued by means of successive editions to be the stand- 

 ard reference book in the subject. The various editions 

 appeared as follows: I, 1837; II, 1844; III, 1850; 

 IV, 1854; V, 1868; VI, 1892 (by Edward S. Dana). 



J. D. Dana also contributed numerous mineralogical 

 articles to the first series of volumes of the Journal. 

 It is interesting to note that they are chiefly concerned 

 with the more theoretical aspects of the subject, in fact 

 they constitute practically the only articles of such a 

 character that appeared during this period. Among the 

 subjects treated were crystallographic symbols, forma- 

 tion of twin crystals, pseudomorphism, origin of minerals 

 in metamorphosed limestones, origin of serpentine, 

 classification of minerals, etc. 



The volumes of the Second Series of the Journal cov- 

 ered the years from 1846 through 1870. This period was 

 characterized by great activity in the study of the chem- 

 ical composition of minerals. A number of skilled 

 chemists, notably J. Lawrence Smith, George J. Brush 

 and Frederick A. Genth, began about 1850 a long series 

 of chemical investigations of American minerals. Very 

 few articles during this time paid much attention to the 

 physical properties of the minerals under discussion, 



