60 
natural history. (Minerals.) 
[north 
latter presented by His Majesty George IV.), many of which are aggre- 
gations of minute crystals . — Native mercury , and hydrarguret of silver 
or native amalgam; the former chiefly as globules, disseminated in cin- 
nabar, sparry limestone, &c. ; the latter crystallized in perfect and mo- 
dified rhombic dodecahedrons, globular, &c. : to which are added some 
figures and ornaments moulded and modelled in amalgam, by the miners 
of Mexico . — Native platinum, massive and as grains: rock specimens 
of the formation in which it occurs in the Ural, Siberia, &c . — Palladium 
and osm-iridium in a wrought state. — The irite of Hermann, found as 
minute scales in hollows of large lumps of platina and in the platina 
sand of the Ural Mountains. 
Case 3. Native gold , subdivided into pure and alloyed gold ; the 
former (though scarcely ever in absolute purity) is chiefly found 
massive, in detached crystals and as grains (in the alluvial deposits of 
Guinea, Sumatra, Bengal, Brazil, Leadhills in Scotland, 8cc.), also in 
brown iron-stone, in quartz, with needle-ore, &c., in Siberia; — the 
alloyed gold (principally from Transylvania) crystallized in minute 
cubes and octahedrons variously aggregated, in reticular plates, &c. 
Of the native alloys known by the names of electrum , that of Smeof or 
Schlangenberg, in Siberia, is best known : it is said to contain one-third of 
silver; but in general the two metals do not unite in definite proportions. 
In this Table Case begin (continued to Case 12) the electro-negative 
metallic substances called metalloids, and their non-oxidized combina- 
tions. — Tellurium and tellur ets : the scarce native tellurium , which ele- 
ment (like sulphur and selenium) has the property of mineralizing several 
metals, combining with them as electro-negative substance, viz — with 
bismuth (a compound formerly called molybdena-silver) from Bastnaes : 
to which also belongs the tetradymite ; — with silver ( tellur-silber of G. 
Rose), from the Savodinsky mine, Altai, Siberia; — with lead ( foliated 
tellurium , or Nagy ag ore ) ; — with silver and lead ( white and partly yellow 
tellurium ) ; — with silver and gold ( graphic tellurium or schrift-ertz of 
authors), all from Transylvania, where they occur in veins traversing 
greywacke and porphyry .- — Native antimony from Allemont, Dauphiny, 
and the scarce antimonial silver or stibiuret of silver from the Hartz, &c. 
Case 4. Native arsenic (formerly called testaceous cobalt and scher- 
ben-cobalt), in reniform and botryoidal shapes, from Andreasberg, &c. ; 
and its chemical combinations (arseniurets ) — with nickel (a variety of 
which is commonly called red or copper-nickel on account of its 
colour) ; — with cohalt , (arsenical cobalt of authors partly,) comprising 
the grey and part of the white cobalt of some mineralogists (to which 
probably belongs the bismuth- cob alt or her stenite of some mineralogists). 
The remainder of this Case contains the substances belonging to the 
orders of Carbon and of Selenium. To the former element are referred 
the diamond, anthracite, and graphite ; to the latter the selenium 
metals or seleniurets. Among the specimens selected to illustrate the 
crystalline forms of the diamond are : — the primitive regular octahedron ; 
the same with solid angles truncated ; with edges truncated, forming the 
passage into the rhomb-dodecahedron ; varieties of the latter, giving 
rise to the six-sided prismatic and the tetrahedral forms ; cubes with 
truncated and bevelled edges ; various hemitropic crystals or macles of 
diamonds ; an octahedral diamond, attached to alluvial gold ; two 
others in a siliceous breccia with cement of hydrous oxide of iron, and 
