and VPoleanie Substances. 239 
Were those climates warmer formerly ? Has the surface 
gradually cooled? Will it account for the supposed in- 
crease of cold in European summers? Or for the supposed 
accumulation of ice in the Alps, or in the polar regions ? 
f the volcanic region in the United States 
Hitherto it has generally been believed that there is no 
evidence of volcanic action or volcanic ejection in the United 
States. Iam persuaded otherwise ; as may be supposed 
from my ranking the flcetz trap formation, among the rocks 
of igneous origin 
[have seen decided specimens of igneous rocks from the 
Mandan village, but I suspect them as pseudo-voleanic. 
We have heard also of volcanoes in the western ae 
toward the commencement of the barren that reaches to 
stony mountains. Of all this, 1 know nothing. 
ess compact and figurate pentagonal basalt, ‘with 
and without pores ‘illed with the carbonat of lime, — 
Mount Holyoke in Massachusetts. I have never bee 
there: but my collection of volcanic matter from various 
countries is pretty extensive ; and I have no doubt on the 
subject of this being a real volcanic ejection, if Basalt and 
Whin be so. 
No person accustomed to volcanic specimens can look at 
the porphyries from the neighbourhood of Boston, in my 
possession, and doubt of their volcanic origin. 
According to the description of Prof. Silliman, i in his inter- 
esting travels to Canada, the floetz trap formation described 
by him as covering the red sand stone through Connecticut, 
is also voleanic.* So is the basaltic region described by Mr. 
Eaton, extending in fact from Deerfield in ar apiece 
ew Haven in Reamantionts The basa a“ greenstone, 
question, Are basalt cod greenstone trap of ie origin ? 
(p- 258.) Ishould venture to say yes: they ar 
From the neighbourhood $ New Haven and Woodbury 
in Connecticut, I possess many specimens of fleetz 
with imbedded prehnite. The volcanic region, deoralere, 
ef * That is, the facts stated in eccapaaad in the hg in ae AB 3 
this point 
8 opinion, j 
the tour to Quebec. —Fa. 
