A New Ore of Uranium. : 175 
ec. The brown substance was dissolved in dilute sulphuric acid, 
and the solution concentrated by heat ; as the ebullition proceed- 
ed, a white precipitate was deposited, which was washed with a 
small quantity of water. When heated before the blowpipe it 
left a white earth, which gave acolorless assay with borax. The 
precipitate was therefore sulphate of thoria. 
©. The solution left after separating the sulphate of thoria, 
was evaporated to dryness, and the crucible ignited, the residuum 
was gray. 
d. This powder was boiled with hydrochloric acid almost to 
dryness ; a fine yellow mass was left, which dissolved in water 
with the exception of a few flocks, (the last portions of the thoria. ) 
The solution gave with ferrocyanuret of potassium a red-brown 
precipitate, it therefore contained uranium. An excess of solu- 
tion of carbonate of soda was added to it; the yellow precipitate 
at first formed, was almost entirely redissolved, a few brown floc- 
culi only remaining, which, when dissolved in hydrochloric acid, 
gave a deep blue precipitate with ferrocyanuret of potassium. 
They were sesquioxyd of iron. 
The constituents of the mineral thus found, are : 
(a. and d.) Protoxyd of uranium, (the peroxyd in (d) being 
formed by the decomposition of the protochlorid in (A). 
b. Alumina. 
¢e. Thoria. 
- Tron. 
A. Carbonic acid, silica and sulphur. 
B. Lim 
. e 
Now the carbonic acid could have been combined only with 
the lime, and the sulphur with the iron. The silica also was in 
very small quantity, ‘These were probably the components of 
the small veins which became apparent on heating the mass. 
Rejecting these we have left protoxide of uranium, alumina and 
oria, as the essential ingredients. ‘The pitchblende from Joa- 
chimstahl in Bohemia., was found by Rammelsberg to be a com- 
The physical characters of this mineral approach very closely 
to those of pitchblende; from which however it may be distin- 
guished by its lustre, and its less specific gravity. The presence 
of the thoria gives this mineral rather an anomalous composition ; 
but as it is contained in a very small proportion, I apprehend 
that it will be found adventitious, or that the same vein will 
eventually furnish specimens of thorite, which being very simi- 
lar in its physical properties, would not be obvious if mingled 
with the coracite. 
