No. 161.] 
53 
the rock in a direction nearly parallel with the former, and at the 
depth of about thirty feet united with it. 
The galena found in this vein sometimes occurs in cubical crys- 
tals, which occasionally have their angles truncated. But it is 
most commonly found in masses imperfectly crystallized, but which 
break into cubical fragments. Throughout the whole extent of 
the vein, the ore is imbedded in calcareous spar, which is easily 
broken and separated from the galena. The proportion of this 
gangue, however, is quite variable, the ore being in some pans 
nearly pure, and separating easily from the rock which forms the 
walls of the vein. 
I have analyzed various specimens of galena from this vein, not 
so much for the purpose of ascertaining the composition of the mi- 
neral, as to determine what proportion of metal could be obtained 
with ordinary care in separating the gangue. 
Analysis of Galena from Rossie^ St. Lawrence county. 
No. 1. No. 2. 
Sulphur, 13.20 Sulphur,... 13.26 
Lead, 85.40 Lead, 85.35 
Carbonate of lime and Carbonate of lime and 
loss, 1.40 loss, 1.39 
100.00 100.00 
No. 1 was part of a cubical fragment detached from the gangue. 
It had a high metallic lustre, and a specific gravity of 7.500. 
No. 2 was a specimen having a lighter colour, and somewhat 
silvery appearance, at least on the surface. This peculiarity ap- 
pears to be owing to some tarnish, or it is perhaps produced by 
the contact of the gangue. 
It will be observed that neither of the above analyses give silver 
as one of the constituents of this ore. I employed the most ap- 
proved processes for the detection of this metal in the humid w^ay 
without success. It is possible, however, that this, like most oth- 
er specimens of galena, would afford by cupellation proportions of 
silver too minute to be detected by the other mode of analysis. 
But I have every reason to believe that the amount would not be 
sufficient to warrant the expense which must be incurred in its se- 
paration. 
