No. 161.] 125 
mining operations. Since the mine at Rossie was opened, nunaer- 
ous other veins of lead have been discovered, but none of them 
will compare for extent with the Rossie mine. This mine is a vein 
, traversing a rock much like gneiss in its general character, but 
takes much hornblende into its composition, though it is not what 
geologists call sienite. The width of this vein is about four feet. 
Much of this space is occupied by the matrix of the ore. The ore 
is regularly found in this space; sometimes it is only a string which 
leads to an expansion of the vein to a foot or 18 inches in width. 
Sometimes the ore is in the midst of its matrix, and again it is near 
the perpendicular walls. It appears to traverse it from side to side 
in a zigzag direction. The vein is continuous as far as it has been 
explored, which is between 30 and 40 rods. The depth to which 
it has been worked is 30 feet in some places, without any diminu- 
tion of the quantity of lead. 
The vein appears as if it had once been a rent in the rock, and 
subsequently filled with mineral matter. Its direction, in one place, 
bears 20° north of west, but in other places it is west. Its di- 
rection downwards is nearly perpendicular. The expense of rais- 
ing the ore is greatly increased by layers of rock, lying across the 
vein, they are called caps; these have to be encountered every 
few feet; they appear like layers which have been slid latterly 
over the vein, yet this is probably not the way in which these caps 
were made to occupy the position we find them, as they usually 
have a thin vein of ore, leading to a larger mass, immediately be- 
neath them. Ii is not easy to account for the frequent intrusion 
of masses of rock, as there is no regularity in their occurrence. 
The immediate gange or matrix of the galena, in the great vein 
in Rossie, and, in fact, in all which have been discovered, is cal- 
careous spar. Several other veins have been discovered in the im- 
mediate neighborhood of this, not in its geographical range. The 
small progress, however, which had been made in opening them, 
when we were there, makes it impossible to offer any thing satis- 
factory, as it regards their prospects. On the Black lake, five 
miles from the village of Rossie, there appears to have been another 
deposite of lead, as in this vicinity also several veins have been dis- 
covered. Not sufficient lead, at either of them, has been raised to 
meet the expense of exploration, and it is probable they will not 
be productive. The course of these veins is westerly, and the 
rock, together with the immediate gangue, is the sarrle as at Ros- 
sie; there is, therefore, a great degree of regularity attending all 
