704 THE AMERICAN NATURALIST.  [Vou. XXXII. 
The italicized portion of the label is written in by hand, the 
rest being printed. The specimens are mounted on painted 
wooden blocks of a pearl gray color. The effect is rather 
cheap. The labels rest on pins on the sloping fronts of the 
blocks. Minerals like ruby silver, horn silver, the bromiodides, 
etc., which are liable to injury from exposure to direct sunlight 
or to very strong diffused daylight, are placed under covers 
made of orange brown glass. These, of course, do not improve 
the appearance of the cases, but they preserve the minerals, 
and they may be readily removed for the benefit of a student. 
The foundation of this general collection was laid more than a 
hundred years ago, hence it has had considerable time in which 
to grow to its present high state of perfection as to the number 
of species represented. 
Special Collections. — There are seven of these: A. Collec- 
tion of the minerals of France and her colonies. This contains 
in particular the types described in “ The Mineralogy of France,” 
by A. Lacroix, each species, however, being represented by 
only two specimens. The primary arrangement is by districts. 
B. Technological series. Under this head are brought together 
those minerals, cut or polished, which are used for ornamental 
purposes, jewelry, bric-a-brac, etc., such as agate, jade, jadeite, 
fluor spar, pagodite, etc. C. Collection to illustrate the occur- 
rence of minerals. In the general collection the minerals are 
considered merely as minerals, but in this new collection they 
are regarded from the point of view of their formation, and are 
classified according to their occurrence and association in 
nature. This is a highly instructive and very interesting series, 
but thus far there have been placed on exhibition only the 
minerals of igneous rocks, those of sedimentary rocks which 
have been metamorphosed by contact with igneous rocks, and 
those of certain calcareous bands, in gneiss. D. Collection of 
cut precious stones. The principal specimen in this gem collec- 
tion is a beautiful blue sapphire weighing 132 carats and cut In 
rhombohedral form. The series of diamonds comprises about 
seventy-five crystals. The beauty of the gem collection 1s 
marred by its unsatisfactory installation. Æ. The Bischoffsheim 
collection of diamond crystals. This is kept separate from the 
