278 A CENTURY OF SCIENCE 



collector of minerals, building up the notable collection 

 that now bears his name. Perhaps, however, his most 

 important contribution to the development of mineralogy 

 in America lay rather in his influence upon his many 

 students. With his enthusiasm for accurate and pains- 

 taking investigation he was an inspiration to all who 

 came in contact with him and his own field and science 

 in general owes much to that influence. 



Among the early mineralogists in this country, who 

 were concerned in the chemical analyses of minerals, 

 none accomplished more or better work than Frederick 

 A. Genth. He was born in Germany in 1820 and lived 

 in that country until 1848, when he came to the United 

 States and settled in Philadelphia. He had studied in 

 various German universities and worked under some of 

 the most famous chemists of that time. His papers in 

 mineralogy number more than seventy-five, in the great 

 majority of which chemical analyses are given. He pub- 

 lished fifty-four successive articles, the greater part of 

 which appeared in the Journal, which were entitled Con- 

 tributions to Mineralogy. In these he gave descriptions 

 of more than two hundred different minerals, most of 

 which were accompanied by analyses. He described 

 more than a dozen new and well-established mineral spe- 

 cies. He was especially interested in the rarer elements 

 and many of his analyses were of minerals containing 

 them. Especially interesting was his work with the tel- 

 lurides, the species coloradoite, melonite and calaverite 

 being first described by him. A long and important 

 investigation was recorded on Corundum, "Its Altera- 

 tions and Associate Minerals," published in the Pro- 

 ceedings of the American Philosophical Society in 1873 

 ( 13, 361 ) . Dr. Genth died in 1893. 



The period from 1860 until 1875 was not very produc- 

 tive in mineralogical investigations. The first ten vol- 

 umes of the Third Series of the Journal, covering the 

 years 1871-1876, contained mineralogical articles by only 

 some fifteen different authors. But from that time on, 

 the amount of work done and the number of investigators 

 grew rapidly. With this increase in activity came also 

 a decided change in the character of the work. The 

 period between 1871 and 1895 can be characterized as one 



