Iviii 



until the death of the latter, in 1864. In 1846 he became an asso- 

 ciate of Professor Silliman in the editing of the American Journal of 

 Science, and after the death of his father-in-law, became the principal 

 editor of that important scientific serial. In addition to his original 

 papers, upwards of 200 in number, he wrote for that journal hun- 

 dreds of abstracts, critical reviews, obituary notices, and notes on 

 many topics. In 1850 he was appointed Professor of Geology and 

 Natural History at Yale College. In 1864, on an increase of the pro- 

 fessoriate, his duties as professor were restricted to geology and 

 mineralogy. In 1892 he formally retired, and last year was made- 

 Professor Emeritus. 



Professor Dana's studies were thus of a manifold character, and as 

 a consequence he achieved distinction in various branches of science 

 mineralogy, geology, and zoology. In the former subject his chief 

 work was his Descriptive Mineralogy, the first edition of which was 

 published at his own expense in 1837 (580 pages), and of which the 

 sixth edition published in 1892, under the superintendence of his 

 distinguished son, Professor Edward Salisbury Dana maintains the- 

 high reputation for completeness and accuracy attained by the pre- 

 vious editions through which this standard work has passed. At the 

 time of the issue of the first edition, the natural history method of 

 classification of minerals was employed by many mineralogists. At 

 first Dana adopted that system, and went so far as to devise su 

 systematic nomenclature on the dual Latin plan ; but in the third 

 edition (1850), the whole system classes, orders, genera, Latin 

 names, and all was rejected, and the importance of chemical com- 

 position was recognised. In the preparation of this work Dana spared 

 | no pains, and to aid in the settlement of the vexed question of 

 \ mineral names, made an exhaustive review of the entire literature of 

 I mineralogical science. He wrote about forty separate papers on 

 ( purely mineralogical subjects ; many are descriptive of particular 

 mineral species, but most of them treat of general subjects, such as 

 nomenclature, pseudomorphism, homceomorphism, and the connection 

 between crystalline form and chemical constitution. 



In geology his work was equally extensive. In 1862 he brought 

 out the first edition of his excellent and well illustrated Manual of 

 Geology, having special regard to the geology of the North American 

 continent. A fourth edition of this work (1087 pages) was issued 

 only two or three months before his death. Each edition of this 

 manual, like those of his Descriptive Mineralogy, was characterised 

 by carefulness and thoroughness of treatment, the last edition being 

 completely re-written from beginning to end. As illustrations of the- 

 variety and philosophical character of his geological studies, we may 

 cite his papers on the origin of the grand outline features of the earth,, 

 the origin of continents, mountains, and prairies, the early conditions 



