Ford— Growth of Mineralogy, 1818 to 1918. 249 



of which nine (mostly phosphates) were new to science. 

 There has certainly been no other series of descriptive 

 papers on a mineralogical locality of equal importance 

 published in this country. 



In addition to publishing original papers, Brush did 

 considerable editorial work in connection with the fourth 

 (1854) and fifth (1868) editions of the System of Miner- 

 alogy and the Appendices to them. His Manual of 

 Determinative Mineralogy, with a series of determinative 

 tables adapted from similar ones by von Kobell, was first 

 published in 1874. It was revised in 1878 and later 

 rewritten by S. L. Penfield. This book did much to make 

 possible the rapid and accurate determination of mineral 

 species. Throughout his life, Brush was an enthusiastic 

 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 o-eneral 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 this 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- 



