51 
GALLERY.] NATURAL HISTORY. 
which sulphuret of arsenic takes the place of the sulphuret of antimony 
of the former;—the miargyrite of H. Rose, first separated by Mohs 
from red silver under the name of hemiprismatic ruby-blende ;—to these 
is related the melan-glance , as are some varieties of the sulphur-salt 
commonly called brittle silver-glance (the roschgewachs of the Hunga¬ 
rian miners), which appears to be composed of the same constituent 
elements as the dark and the bright red ruby-silver ores, but in different 
proportions;— bournonite , a sulphur-salt known also by the names of 
endellion, and triple sulphuret of lead, antimony, and copper, chiefly 
from Hungary and the Hartz :—the scarce polybasite. There are 
some other substances belonging to this order, such as, in 
Case 12, the fahl-ore or grey copper (a double sulphur-salt, on the 
chemical constitution of which much light has lately been thrown by 
the researches of H. Rose), crystallized, massive, and disseminated in 
various substances; the more remarkable specimens are those from Hun¬ 
gary. The remaining space in this Case is occupied by the following 
sulphurets :—* sulphuret of arsenic , viz. the yellow orpiment , massive and 
in striated, separable laminae; and the red orpiment or realgar, 
perfectly massive and crystallized, but decomposing by the action of 
light into an orange-coloured powder;—several of the arsenio- 
sulphurets , such as the arsenic-pyrites or mispickel (some varieties of 
which, containing accidentally admixed silver, constitute Werner’s 
weiss-ertz) ;—the cobalt-glance, massive and crystallized in the form of 
the cube and its modifications &c., chiefly from Tunabergin Sweden;— 
the sulphuret of molybdenum or molybdena-glance, sometimes con¬ 
founded with scaly varieties of graphite. 
In the six following Cases the oxides of the electro-positive metals 
are deposited. 
Case 13 contains the oxides and hydrous oxides of manganese, 
formerly distinguished as foliated, compact, and earthy grey manganese ; 
but now, from chemical and crystallographical distinctive characters, 
divided into the species called manganite, pyrolusite, psilomelane, 
hausmannite, braunite, &c., to several of which, but particularly the 
first two, may be referred the earthy manganese or wad, (a name also 
frequently given to earthy cobalt,) some varieties of which have the 
property of inflaming spontaneously when mixed with linseed oil. To 
these may be added the franklinite, in the next case, a mineral sub¬ 
stance composed of oxides of iron, zinc, and manganese. 
Case 14. In this and the two following Table Cases are deposited 
most of the oxides of iron :— magnetic iron-ore, (magneteisenstein 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, of which several specimens are placed in this 
Table Case:—crystallized, compact and granular varieties, in ser¬ 
pentine, chlorite-slate, &c. ; variety with granular quartz, from the East 
Indies, which yields the wootz, or salam-steel, remarkable for its hard¬ 
ness ; magnetic iron-sand. 
Case 15. Specular oxide or iron-glance, among the specimens 
which may be specified those from Elba, remarkable on account of 
their beautiful iridescence 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 
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