514 Metals. MIN E R 
7. Cobaltum cryftallinum, or grey cobalt ore: of a 
bluifh-tin colour and luftre; emitting fulphurous, and 
arfenical vapours before the blowpipe, and leaving a mag¬ 
netic bead. Found in the mines of Cornwall, and va¬ 
rious, parts of Europe ; of a dull grey colour, with the 
furface often tarnished: the cry Hals are ufually fix-fided- 
prifms terminated at each end by an irregular fix-fided. 
pyramid, fo that the cr.yftal coniifts of fix tetragons and 
twelve hexagons, with the faces ftriate in an oppofite 
manner : its primitive form is a cube, the durfaces of 
which .are remarkably brilliant. It contains cobalt 44, 
arfe'nic 55'5, fulphur 0-5. Cobalt alloyed with arfenic is 
reduced to the Hate of the limple oxyd of cobalt by the 
procefs of roaHing: the oxyd is extenfively ufed in the 
arts, for the purpofe of giving a blue colour to glafs, and 
enamels, &c. During the roaHing, the arfenic is fepa- 
rated in the Hate of a white oxyd, and is depofited in 
Hues communicating with the chambers where the ore is 
roafied. From the nature of the fiubflance depofited, thele 
flues are ufually called poifon-flues ; and probably from 
the fame circumfiance the German miners gave this me¬ 
tal the name of cobalt, which literally fignifies an evil 
Jpirit. The white fumes and the Hrong imell of garlic 
"emitted from this variety of cobalt, and its property of 
communicating a blue colour to glafs of borax, diliinguilh 
it from all other minerals. 
8. Cobaltum arfenicale, or arfenical cobalt: of a dull 
Heel-grey colour and luftre ; emitting arfenical vapours 
before the blowpipe, and leaving a magnetic bead. Found 
in the mines of Europe, accompanying the other cobalt- 
ores ; of a granular texture approaching to the flat or 
conchoidal, rarely fibrous in a parallel Hellate or fafcicled 
manner; of a common or botryoidal form, fometimes 
marked with black flirub-like lines: it greatly refembles 
the preceding. 
9. Cobaltum Hifpanicum, or Spanifli cobalt: of a Heel- 
white colour and luftre; emitting fulphurous and arfeni¬ 
cal vapours, and leaving a bead not attrafted by the mag¬ 
net. Found in the mines of Arragon in Spain ; and con- 
HHs of cobalt, fulphur, and arfenic, without a vifible mix¬ 
ture of iron. 
Magnesium, Manganefe. See vol. xiv. p. 108, 9.— 
Since that article was printed, we have met with Haiiy’s 
Tableau eomparatif, which notices, 
10. Magnefium pholphoratum, or phofphat of manga- 
fiefe. “ Phofphat of manganefe (lays Haiiy) hitherto ex- 
clufively belongs to the foil of France, in which it has 
been difeovered by the elder M. Alluau, a very learned 
thineralogifl, near Limoges, in the heart of a granite, and 
in the fame quartz-vein which contains the beryls. On 
breaking fome pieces of this fubflance M. Alluau had the 
goodneis to give me, I obferved that, of the three natural 
joints which appear to be perpendicular to one another, 
two, poffelfing the fame diftinCfnefs, are more fenfible and 
more ealily obtained than the third ; whence we may pre- 
fume that the primitive form is not a cube, butaflraight 
prifm with fquare bales, of a different extent from that of 
the fides.” 
Tungstenum, Tungflen, or Wolfram.—Generic cha¬ 
racters : Greyifh or brownilh, internally Heel-white ; very 
brittle and hard; not attracted by the magnet; lpecific 
gravity, 174; filling'with great difficulty, gradually 
changing from a black to a yellow oxyd when heated, 
which, with the addition of microcofmic fait, is at laH con¬ 
verted into a blue glafs ; foluble in the nitric acid into a 
veilow oxyd. 
There is hardly any metallic fubflance that occafions 
greater difficulties to practical chemifls than tungflen, 
both on account of j.he want of a good procefs to obtain 
its peroxyd in a Hate of purity, and on account of the very 
high temperature which is requifite to melt the tungflen 
after it has been reduced to the metallic Hate. The expe¬ 
riments of the El Luyarts are known to every chemilt; 
as are likewife the elaborate trials of Vauquelin and Hecht. 
A L O G Y. Metals. 
Meffrs. Allan and Aikin fucceeded in reducing it to the 
metallic Hate, and verified its great fpecific gravity as de¬ 
termined by the Spanifh chemifls. An elaborate fet of 
experiments on this metal were publifhed fome years ago 
by JBucholtz. He afeertained that the methods hitherto, 
employed by chemifls for procuring pure tungftat of am¬ 
monia do not lucceed ; and he verified the great fpecific 
gravity of this metal, having obtained it in grains of the 
fpecific gravity 17-4. Now this is the mean of 17-6 given 
by the El Luyarts, and 17-2 given by Allan and Aikin. , 
The literal meaning of the word Tungflen is heavy - 
ftove. The metal was fo called from the great fpecific gra¬ 
vity of the mineral in which it was firfl difeovered. It is 
alfo called Scheelium: in honour of Scheele, who firfl af¬ 
eertained the real nature of this mineral. It exifts in two. 
natural forms ; in one of which it is combined with lime 5 
in the other, with iron and manganefe ; the firfl is ufually 
called Tungflen ; the laft Wolfram. 
1. Tungflenum calcareum, tungftat of lime, ortung- 
ften : ponderous, lamellar, extremely brittle, yellowilh- 
white or grey; digelted with hot nitric acid, becoming 
yellow. Many of the fpecimens of tungflen met with in 
cabinets come from Zinnwalde in Bohemia; and are ac¬ 
companied with mica cryftallized in hexagonal plates, and 
with fmoky quartz. Numerous minute cryftals of tung- 
ften fometimes incruft the furface of the latter fubflance. 
Tungflen is alfo met with in Cornwall; and in Sweden. 
It ufually accompanies tin-ore ; and was at firfl miftaken 
for a white variety of native oxyd of tin ; from which it 
may be diftinguilhed by the change of colour it undergoes 
when thrown into nitric acid. It is diftinguilhed from 
carbonat of lead by not effervefeing with an acid, and in 
not being blackened by an alkaline fulphuret; from ful- 
phatof barytes by its greater lpecific gravity, and by the. 
yellow colour it affumes when thrown into nitric-acid. 
Specific gravity ? from 5 - S to 6. Contains oxyd of tung- 
ften 70, lime 30. 
2. Tungflenum magnefiatum, tungftat of manganefe, 
or wolfram: very ponderous, lamellar, opake, of a blackilh- 
brovvn colour and reddilh-brown ftreak, forming a green- 
ilh glafs with borax. Found in Cornwall, Spain, Brittany, 
Saxony, and Bohemia, in tin-mines, maflive or cryftallized 
in right-angled four-fided tables, or fix-fided compreffed 
prifms ending in four-fided fummits ; texture foliated, 
and eafily feparated into plates by percuflion : it is infu* 
fible by the blowpipe, and forms a deep red glafs with mi¬ 
crocofmic fait. Specific gravity, 7-333. Contains oxyd 
of tungflen 65, oxyd of manganefe 22, oxyd of iron 13. 
Plate VII. fig. 1 is an ore of native nickel. This is 
what the German miners call hupfer-nichel, or fparkling- 
copper; it contains, however, but little copper. 
Fig. 2 is an ore of calamine, or oxyd of zink, in four- 
fided figures, with a fmooth furface, and bone-like ap¬ 
pearance where broken. From the Halken-mountain in 
Flintlhire. Fig. 3 is yellow calamine, called waxen cala¬ 
mine, in figures forming hollow fquares. From a mine 
near Workfworth in Derbylhire. Fig. 4 is reddilh-brown 
calamine-ore, in hollow triangles, like the corners of 
cubes of fluor, projecting on the ftone ; the fluor being 
decompoled, and calamine fubftituted in its place. A 
rare follil, from Bonfal Dale in Derbylhire. 
Fig. 5 is an ore of bifmuth mixed with cobalt. 
Fig. 6 is an ore of antimony with large Arise ; i. e. as if 
compoled of large needles glued together; the needles 
lie in different pofitions. Sometimes the whole mafs is 
luperficially tinted with livid blue, or with iridefeent co¬ 
lours, which arifes probably from a mixture of vitriol, and 
has a pretty effedf. Between the needles there are hol¬ 
lows or interftices which exhibit a bright luftre, as if po- 
lilhed. Fig. 7 is a mafs containing large needles conglu- 
tinated, having an ochraceous covering, but without any 
ftony fubflance. The needles here lie in all directions; 
they are livid with a filvery glofs. Fig. 8 an ore of feather¬ 
ed antimony, confifting of eifiorefcences of a feathery or 
even cottony nature. Thele ores are moftly reddifh, fome- 
3 times 
