262 Lead Mines, &c. of Hampshire County, Mass. 
thus forming granite veins in granite veins. What leads to 
this conclusion is the fact, that small granite veins in mica 
slate, often contain in themselves still smaller granite veins. 
These granite veins in granite are of all sizes, from a mere 
line in breadth, up to three or four feet. They are as firmly 
attached to the granite in which they are situated, as the 
granite is to itself, and upon a fracture, one side of the vein 
will cleave to the granite on its side, and the other to the other 
side ; but they are in reality granite veins. ‘They are of a 
coarser texture than the granite in which they are situated, 
and of so different a complexion, that they may be distin- 
guished at the distance of a furlong, and not unfrequently 
they dash off into mica slate, lying next to granite. See figures 
1, 2and 6, at the end of this communication. 
hese granite veins run in all possible directions ; some- 
times they run parallel one with another, and continue their 
breadths for rods, with mathematical exactness, and then 
grow narrow or run into one another. Sometimes they con- 
verge gradually together, and then diverge again into their 
former distances from one another; at other times they meet 
at a focus from all directions, as in figures 3 and 4; then 
again parallel veins will be cut off by one running at right 
angles with them, and these parallel veins branch out or 
into one another; and some of them are jogged out of 
their course a foot, or two or three feet, to the right or left, 
forming shoulders as in figures 6 and 7, while other pat- 
allel veins with them continue their accustomed course. 
have often seen veins in mica slate send off branches across 
the mica slate, into the neighbouring granite, as in figure 2, 
and often a vein of granite in mica slate will run parallel with 
the strata, and another vein then turns directly across the 
strata, and across the parallel vein to the other side, and then 
turns again about at the same angle, into the strata, and runs 
parallel again, asin fig. 1. Sometimes they gradually nar- 
row and come to a point as may be seen in several figures 
in this communication. The granite veins in granite and in 
mica slate, as well as hornblende veins in mica slate, all seem 
to be perfectly analogous to the galena veins in this region, 
and so far as the granite and hornblende veins are concerned, 
Must say that they seem to be cotemporaneous, or near! 
So, ¥ th the rock in which they are situated. They all adhere 
firmly to the rocks in which they are found, without the least 
fracture or fissure between them. 1 ought to have mentioned 
es 
