Vol. 69.] ANNIVERSARY ADDRESS OF THE PRESIDENT. IV 



further study he then went to Germany, and, on receiving an 

 appointment as Professor of Metallurgy in the Yale Scientific School 

 in 1855, extended his experience by studying at the lloyal School 

 of Mines, London, and by visiting the chief mines and smelting- 

 works of Great Britain and the Continent. 



The scientific department of Yale College, which had lacked both 

 funds and organization, was enriched in 1860 by the liberality of 

 Mr. Joseph E. Sheffield, and became known as the Sheffield Scientific 

 School. To its organization Prof. Brush thenceforward devoted 

 his great administrative abilities ; but, although as Secretary, 

 Treasurer, and eventually President of the Board, he took a leading 

 part in its affairs, he maintained to the last his interest in the 

 subject in which he had specialized as a boy. His collection of 

 minerals became notable for its completeness for the purposes of 

 scientific study, and for the care with which it was arranged and 

 catalogued. It was presented to the Sheffield Scientific School in 

 1904, and will remain at Yale as a permanent monument to its 

 founder. Among his published works mention must be made of 

 the ' Manual of Determinative Mineralogy.' He contributed also 

 largely to Dana's ' System of Mineralogy,' and in his presidential 

 address to the American Association for the Advancement of Science 

 at Montreal in 1882, he summarized the early history of American 

 Mineralogy. 



He was elected a Foreign Correspondent of this Society in 1877, 

 and a Foreign Member in 1891. Previously, in 1868, he had 

 been elected a member of the National Academy of Sciences ; and 

 in 1886 he received the degree of Doctor of Laws at Harvard. 



He died on February 6th, 1912, in the 81st year of an eminently 

 active and useful life. 



By the death of Geheimrath Professor Ferdinand Zirkel, the 

 geological world has lost a pioneer in the science of microscopical 

 petrography, and the Geological Society one of its oldest and most, 

 distinguished Foreign Members. He was born at Bonn on May 20th, 

 1838; and, although the greater part of his long and active life was 

 spent away from that city, he always regarded it as his home, re- 

 turning to it whenever his professorial and other duties permitted. 



In 1855 Zirkel entered the University of Bonn, applying him- 

 self especially to chemistry and mineralogy, and to practical work 

 in the mines of Bhineland, with a view to the career of a mining 

 engineer. But, before he had completed his studies, the opportunity 



