160 NATURAL HISTORY. [NORTH 
modified rhombic dodecahedrons, globular, &c. : to which are added 
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_ Palladium and 
osm-iridium , in a wrought state. 
Case 3. Native gold , subdivided into pure and alloyed gold; the 
former chiefly massive, in detached crystals and as grains (from al¬ 
luvial deposits of Guinea, Sumatra, Bengal, Brazil, Leadhills in Scot¬ 
land, &c.), and in brown iron-stone, in quartz, with needle-ore, &c., 
from Siberia ? the alloyed gold (principally from Transylvania) crystal¬ 
lized in minute cubes and octahedrons variously aggregated, in reticular 
plates, &c. With these are placed a few specimens of the alloys known 
by the names of auriferous silver and electrum. 
In this Case begin (continued to Case 12) the electro-negative me¬ 
tallic substances (metalloids), and their not oxidized combinations.— 
Tellurium and tellurets : the scarce native tellurium , which (like sulphur 
and selenium) has the property of mineralizing several metals, combin¬ 
ing with them as electro-negative substance, viz—with bismuth (for¬ 
merly called molybdena-silver) from Bastnaes : to which also belongs 
the tetradymite ; — with silver , from the Altai, Siberia ; — with lead (foli¬ 
ated tellurium, or nagyag ore);—with silver and lead (white and partly 
yellow tellurium) ;—with silver and gold (graphic tellurium or schrift- 
ertz of authors), all from Transylvania.— Native antimony from Dau- 
phinv, and 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 (commonly 
called copper-nickel) ;— with cobalt , comprising the grey and part of 
the white cobalt of some mineralogists ;—with bismuth (kerstenite.) 
The remainder of this Case contains the substances belonging to the 
confined orders of Carbon and of Selenium. To the former are re¬ 
ferred 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 rhombic 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 some alluvial gold; two 
others in a siliceous breccia with cement of hydrous oxide of iron, and 
one in compact brown iron stone, from Brazil; models of large dia¬ 
monds, &c. With these are placed specimens of the alluvial rock in 
which this precious substance occurs in the East Indies and in Brazil. 
Varieties of anthracite or kohlenblende (to which may be referred the 
Kilkenny coal), from various localities, with native silver from Kongsberg, 
&c. ; —graphite (commonly called black-lead), massive, disseminated in 
porcelain earth, &c.— Seleniurets: lead seleniuret;—copper and lead 
seleniuret;—mercury and lead seleniuret, all from Tilkerode, Hartz; 
—cobalt and lead seleniuret;—copper seleniuret;—copper and silver 
seleniuret ( eukairite ), both from Strickerum, Sweden ;—to which are 
added specimens of sulphur, from the island of Volcano, incrusted and 
coloured by reddish-brown or orange-red particles of selenium. 
