62 Report of the President 



Hall of Minerals, and, viewed in this light, the percentage of 

 students in the whole number of the attendance is much above 

 fifty per cent., a very satisfactory evidence of the serious use 

 of the collections. The people, preponderatingly men, who 

 remained in each hall for a considerable time evinced a studi- 

 ous interest, attributable perhaps to previous knowledge, or to 

 newly awakened recognition of the character and beauty of 

 minerals, though obviously, in the Gem Room, their attention 

 partook of the popular admiration that gems universally excite. 



The Collection of Minerals, during the past year, has been 



enriched by a very considerable group of specimens, some of 



which have unusual beauty, some are of phenomenal 



size, while among the additions are specimens of 



rare or lately described species. 



The collection has been enlarged by the addition of two 

 hundred specimens, among which may be mentioned some 

 interesting examples of the change from Anhydrite to Thau- 

 masite, both found in the New Jersey trap-rocks, confirming 

 the discovery of Mr. Frederick I. Allen of the origin of the 

 latter singular compound, through a progressive alteration in 

 the former. Some of the specimens, together with others illus- 

 trating the origin of the diamond-shaped cavities in the New 

 Jersey Zeolites and Quartzes, of the trap region, as derivative 

 from vanished crystals of Glauberite, will appear in Dr. W. T. 

 Schaller's forthcoming Bulletin (United States Geological 

 Survey). A Neptunite specimen of great size and richness, 

 rivaling the examples now in the National Museum at Wash- 

 ington ; a superb series of the Pyrites of Colorado with others 

 from Utah, remarkable for their beauty, size and crystallo- 

 graphic novelty; Tellurium crystals (furnace products) ; addi- 

 tions to the suite of Californian precious and parti-colored 

 Tourmalines; Benitoite (the unique gem-stone of California 

 now rapidly disappearing in the mineral market) ; some ad- 

 mirable crystallized Golds, and a large single nugget of Gold 

 from the placer of Hunter Creek, Alaska; an astonishing 

 crystallized surface of Dioptase from Siberia; Native Copper 

 in clustered strings of crystals, with Calcite, from Bisbee, Ari- 

 zona; and rare or new species, such as Ampangabeite, Beta- 



