Tungsten and Tellurium. 407 
5. This powder is infusible by the blow-pipe, but ignited 
with borax in a platinum crucible, it became of a superb blue, 
like smalt, or between that and Prussian blue. 
6. The quantity obtained was too small to make it conve- 
nient to attempt its reduction to the metallic state; no doubt 
remained, however, that it was oxyd of tungsten, or as it is 
sometimes called, tungstic acid. 
7. There were traces of manganese, and all the facts per- 
haps justify the conclusion, that the ore is very similar to the 
silt tungsten or wolfram. 
. The calcareous tungsten occurs in octahedral crystals, 
«4 we have not before heard of this form in the ferruginous 
species, which generally affects the Brinpatics! forms. 
B. REMARK. 
We had been for some time inclined to believe, that the 
above ore was’ferruginous tungsten, but although fortified by 
the opinion of Col. Gibbs, we were witheld from RE 
it, because the form of the crystals, the specific gravity, th 
color, and perhaps some other characters, were not viecteetty 
accordant with European descriptions, and with the specimens 
in our possession, which are from Saxony and Cornwall. 
During the necessary chemical trials (which have, we trust, 
established the correctness of the above opinion,) we very 
unexpectedly discovered in some of the ores of tungsten, proofs 
of the existence of tellurium. The conclusion was induced 
by the phenomena, for nothing was farther from our expecta- 
tions. 
Two fragments were pulverized by an assistant, and we 
therefore cannot say whether they had any external characters 
different from those of the other pieces; they came, however, 
from the same part of the vein, and their powder resembled 
that of the other pieces. 
1. Digested in nitro-muriatic acid, a straw-yellow solution, 
slightly inclining to green, was. obtained, and a black paméer 
was left behind. 
2. More acid digested on this powder, gave a deep red solu- 
tion of iron, and left the yellow oxyd of tungsten, which being 
+ 
