408 Hydrate of Nickel, a New Mineral. 
as taken in small fragments with the specific gravity bottle. Its 
lustre is highly vitreous and its fracture uneven and scaly. It is 
extremely brittle and is readily pulverized, giving a light yellowish 
green powder; it is very easily detached from the gangue on 
which it rests. Its pyrognostic character is perfectly decisive. 
Alone in a close tube it affords a copious yield of water, which 
is neutral to test paper; and it loses its fine color at a temperature 
but little above 212°; with a higher heat it becomes blackish 
~ gray and is then quite unchanged by long continued heat. 
empyreumatic odor is also found in the tube when it is heated. 
It forms no bead with carbonate of soda in either flame of the 
blowpipe ; with borax, it readily fuses into a transparent bead, of 
a dark yellow or reddish color when hot, and nearly colorless when 
cold. In the reducing flame, with a larger quantity of the min- 
eral, the bead becomes gray and opake from the presence of nu- 
merous particles of finely divided metallic nickel which cannot, 
by long blowing be fused into a bead. On crushing this borax 
i e mortar under water, a gray powder appears, 
which is strongly attached by the magnet, and which burnishes 
under the pestle, showing the reddish white color of metallic 
nickel. With salt of phosphorus its behavior is precisely like 
the artificially prepared oxyd of nickel. An examination in the 
wet way detected only trifling traces of oxyd of iron and perhaps ~ 
alumina. It dissolves completely and with very slight heat in di- 
lute chlorohydric acid, and the few black particles which collect. 
on the bottom of the flask are minute flakes of chrome iron me- 
_ chanically entangled in the mineral. The solution has the fine 
grass green tint which belongs to the salts of nickel. Sulphuret- 
ted hydrogen produces no turbidness in the solution, and no traces 
of oxyd of chrome could be detected. Indeed the blowpipe de- 
cisively indicates the absence of this oxyd, since an exceedingly 
small trace would give the borax glass its characteristic green tint 
when cold. The beautiful green color of this mineral, as ound, 
led no doubt to the supposition that it was the native green oxyd 
of chrome, which seemed a plausible conjecture. Its water was 
determined by ignition of a weighed quantity of the mineral in a 
carefully counterpoised platinum crucible, cooling after ignition 
in a desiccator over sulphuric acid. It lost as the mean 0 
trials 38-50 pr. ct. of water, which is rather more than two atoms. 
Its constitution will probably be correctly expressed by Ni2H. It 
will be remembered that the artificial hydrate of nickel prepared 
by precipitation with potash from the nitrate is Ni Hf or only one 
atom of water. 
The discovery of the composition of this mineral led me t 
amine the composition of several specimens of carbonate of ead 
or 
0 ex- 
. 
nesia from the same mines, which have a green tint more 
