NATURAL HISTORY. 
48 
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metallic 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 (a com¬ 
pound formerly called molybdena-silver) from Bastnaes : to which also 
belongs the tetradymite ; — Wtfhsilver, from the Altai, Siberiawith lead 
(foliated 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, where they occur in veins 
traversing greywacke and porphyry .—Native antimony from Dauphiny, 
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 
orders of Carbon and of Selenium. To the former 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 
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 (the purest and 
most compact variety of which is that from Cumberland)/disseminated 
in porcelain earth, &c. 
Selenium is found in chemical combination with several metals: 
the seleniurets here deposited are : lead-seleniuret; — copper-lead- 
seleniuret;—mercury-lead-seleniuret;—cobalt-lead-seleniuret, all from 
Tilkerode, Hartz ; — copp^r-seleniuret; — copper-silver-seleniuret 
( eukairite ), both from Strickerum, Sweden ;—to which are added spe¬ 
cimens of sulphur, from the island of Volcano, incrusted and coloured 
by reddish -brown or orange-red particles of selenium. 
Case 5. The suite of specimens of sulphur (among wdiich may be 
specified the splendid crystallizations from La Catoliea in Sicily, and 
from Conilia in Spain, the stalactic, and other varieties, accompanied 
by selenite, sulphate of strontia, &c. ; and the massive and pulverulent 
sulphur found sublimed near the craters of volcanos, &c.) is succeeded 
by the Sulphurets ,-which occupy half of this and seven of the next fol¬ 
lowing Table Cases. They begin with sulphuret of manganese or man¬ 
ganese-blende, from Nagyag in Transylvania and from Peru.—Among 
he numerous varieties of sulphur et of zinc, or zinc-blende, may be 
articularized those relative to colour, viz., the yellow, the brown, and 
