' 
is Geology, §c. of the Connecticut. 
mass will thus be cut up into segments of pseudomorphous 
erystals. And so it is in the natural specimens: and it 
seems as though the hand of ici had really made use of 
a saw in their construction. The plates of mica meet at 
various angles, yet never cross each other; and the smallest 
piece of quartz or felspar is sometimes bisected, so that a 
part appears on one side of the plate of mica and a part on 
the other. This rock occurs in the S. Hampton granite ; 
and may frequeotly be found in other parts of the region 
extending fifty miles south from Conway. Ata little dis- 
tance the dark bronzé coloured mica appears like prisms of 
some imbedded mineral: and the travelling geologist is of- 
ten tempted from his carriage in the almost certain expecta- 
tion of obtaining from this rock shor] or titanium. 
2. GNeEIss. 
Coloured Orange. 
Although this is the most abundant re in New-England, 
yet the map includes no very extensive portion of it. It 
stretches over a broad region without the limits of the ma 
on the east and west, especially on the east. On the west it 
forms a part of the Hoosack or Green Mountains; though a 
much less part than has been usually supposed. On the east 
appears with some interruptions of granite, mica slate, &c. 
within twenty or thirty miles of the coast, and on the north 
it spreads over a considerable part of New-Hampshire. 
The White hills are said to consist chiefly of this rock : 
though they have not, I believe, been thoroughly explored. 
The dip of the layers of gneiss in this region varies frora 
20° to 90°—and it dips, like most other stratified rocks along 
the Connecticut, to the east. When it approaches to horp-— 
blende slate the dip is generally greater than when pure. 
This rock often contains crystals of hornblende; in every 
propertion, indeed, until the characters of gneiss are lost in 
hornblende slate. Especially is this the case on the east 
side of Connecticut river. More, however, will be said on 
this subject when we come to describe hornblende slate. 
ood examples of this gneiss containing detached crystals and 
even veins of black hornblende may be seen in the base- 
ment of the new Collegiate Institution in Amherst. It fur- 
