gallery.] natural history. (Minerals.; 65 
varieties of which exhibit spontaneous combustion when mixed with 
linseed oil. 
Case 14. In this and the two following Table Cases are deposited 
most of the oxides of iron :—magnetic iron-ore or magnetite (magnet- 
eisenstein of Werner), a compound of protoxide and peroxide of 
iron, most of the varieties of which are strongly attracted by the magnet, 
'while some of them possess polarity in a high degree (natural magnets), 
of wdiich several specimens are here deposited:—among the more 
interesting crystallized varieties may be particularized those from Tra- 
versella in Piedmont: among the granular varieties that from the East 
Indies, which yields the w r ootz, or salam-steel, remarkable for its hard¬ 
ness ;—magnetic iron-sand. 
Case 15. Iron-glance or specidar oxide, among the specimens of 
wdiich those from Elba are much admired for their beautiful iri¬ 
descence and play of colours; the variety in large laminar crystals 
appearing like polished steel, from Stromboli and Vesuvius;—the 
micaceous iron-ore of Werner, belonging partly to this species, partly 
to hydrous oxide of iron;—also the red iron-ore , generally divided 
into compact red iron-stone and red hematite , are now considered as 
a variety only of this species. 
Case 16. Hydrous oxide of iron or brown iron-stone , among the 
most remarkable varieties of which species are, the micaceous, called 
gdthite , in delicate transparent tables of a blood-red colour; that in fine 
scales coating the cells of lava; a shining brownish-black variety used 
as hair powder by the Bootchuana natives beyond the Great River in 
South Africa; the fibrous brown iron-stone or brown hematite; the 
compact and the ochrey brown iron-stone. With these are placed speci¬ 
mens of several sub-species of argillaceous or clay iron-stone, such as the 
columnar, the reniform, the pisiform (pea-ore): among the varieties here 
deposited of this latter, is a sample of the rounded and angular grains 
from the size oi a millet-seed to that of a small hazel nut, wdiich, on the 
10th of August, 1841, descended as a shower at Iwan, in the Comitate 
of Oedenburg in Hungary, and were considered as a new r species of real 
meteorites, until their terrestrial origin w 7 as fully ascertained by micro¬ 
scopic observation and analysis. 
Case 17. Oxide of copper :—red or ruby-copper (cuprite, Haid.), 
compact and foliated, of which the finest crystallized varieties occur 
in the Bank mines, Siberia, and in Cornwall: one of the more re¬ 
markable varieties is the bright-red capillary cuprite called chalco - 
trichite, (in which selenium has been found by Kersten,) from Rhein- 
breitenbach;—the tile-ore, most varieties of which are intimate mixtures 
of red copper and brown iron-ochre, from Hungary, Siberia, &c. ;—the 
tenorite of Semmola, a pure oxide of copper occurring in six-sided 
filmy plates, on the rifts of some Vesuvian lavas;—the black oxide or 
melanoconite, generally found mixed with the oxides of iron and man¬ 
ganese. Oxide of bismuth or bismuth-ochre, from Saxony and Bo¬ 
hemia .—Red oxide of zinc (zincite of Haidinger, also called spar - 
talite and sterlingite ), from Sparta in New Jersey; to which is added, 
from the same locality, th efranklinite, a mineral composed of the oxides 
of zinc ancf manganese .—Black and yellow earthy cobalt, both called 
cobalt-ochre, which seem to be hydrates of the oxides of cobalt and 
manganese, frequently mixed with oxide of iron. — Oxide of uranium, 
or uran-ochre, occurring at Johanngeorgenstadt. and Joachimstha! 
