Editorial Conimcnt. 113 
These economic collections are the most systematic of their 
kind in the country, and in many respects the most complete 
and systematic of any public museum in the world. 
By law, as noted above, the museum is the repository of all 
mineralogical and geological material collected by the various 
departments of the government, when the various investiga- 
tions for which they were made are completed. This results 
in bringing together a vast amount of material, worthy of pres- 
ervation, in fact, of the very greatest scientific value for refer- 
ence and study purposes, but cjuite unsuited for exhibition. 
Materials of this nature are classified by kinds or by areas, ac- 
cording to the conditions under which they have been studied, 
and put away in drawers in storage cases, where they may be 
available whenever desired. Among the more important col- 
lections, which may be mentioned here, are those made by the 
early Hayden and Wheeler surveys ; the tenth census iron ore 
series described by Pumpelly ; the collections of the 40th par- 
allel survey, including the lithological series described by Zir- 
kcl ; the Washoe collections representing the work done by G. 
F. Becker and colleagues in the Washoe district and Comstock 
lode, Nevada, the results of which were published in Mono- 
graph 3 of the U. S. Geological Survey ; the rocks of the Eu- 
reka district, as described by Hague and Iddings, in mono- 
graph 20, U. S. Geological Survey ; the Pacific coast quick- 
silver collections, comprising several hundred specimens as 
described by G. F. Becker and colleagues in monograph 13 of 
the U. S. Geological Survey ; the Leadville collection, compris- 
ing nearly four hundred eruptive, sedimentary and metamor- 
phic rocks and ores collected and studied by Messrs. S. F. Em- 
mons and Whitman Cross, and described in monograph 12 of 
the U. S. Geological Survey. It also includes type series of the 
rocks described by the survey petrographer.s — as those of the 
Silver Clifi^ and Ten Mile districts, Colorado — and representa- 
tive series of rocks of the various ]nil)lished quadrangles. 
The mineral collection is evidently very systematic and con- 
tains much material worthy of special mention. Among the 
more noteworthy specimens is a fine large octahedron of gold 
and a cluster of crystallized gold showing nearly 20 more or 
less perfect octahedra- The collection also contains type speci- 
mens of warrenite, hanksite, spangolite, lawsonitc, zunyite, and 
