236 Dr. Cooper on Volcanoes 
We must explain, (if we do attempt explanation) a doubt- 
ful fact, by its analogies, not to what we may suppose, but 
to what we know, and to that only. 
I take a piece of hard clink stone hackly basalt: I offer 
it to the reader, I say to him, “vou are a chemist: this 
piece of floetz trap weighs ra agi ’s avoirdupois : how 
much water will it take to dissolve 
Well : but you urge, the enc does not require solu- 
tion, only suspension—be it ow came these pores, 
in a stone gradually ebdisblidated ‘and indurated from a paste 
coarse or fine, suspended in water? Did you in any other 
case ever witness a similar Ba of a stone from its 
parts diffused in water? Is not sucha oa common in 
pseudo-volcanoes and in the seo of furnaces 
Again: how can a soft pasty mass, form a rough ragged 
peak as Ae cht of a mountain ? 
gain: how can a pasty mass find its way upward, for- 
cing acta, fonsing one one +44 upward, and another down- 
ward ofa series thomable depth, till it ar- 
rives at the Sos! as in oie ae lt of Whin-Dykes? Read 
account of Dykes in 4 Geol. trans. and account = them if 
you can by aqueous solution, or aqueous suspensio 
Look at the ice in winter in any of our great rivets =< o 
cially at the time of their breaking uP in the spring. 
exact analogy of peaks, rough summits, prominencies of all 
shapes and sizes, and in all directions, rough masses formed 
one over another, the result of great presure a tergo of li- 
quid masses suddenly congealed, will strike you at once 
« The fields of extinct Volcanoes which 1 have had the 
opportunity a examining (says M’Clure, 1 trans. of the 
Philad. Academy of Sciences, p. 332) were as similar as 
possible in their component parts and relative position. / 
extensive field round Oilok? ieee Hamila, and at Cap de 
t in Spain—round Rome—between Rome and Florence, 
and in the Vincentin in Italy—in Auvergne in France— 
round Andernack on the Rhine—at Cassel in Germany— 
all of them, leave no doubt on my mind of their volcanic or- 
igin. In all of them I found abundance of Basalt; in some 
of them i Soe part of the solid Lavas was in the 
of b The Austrian police prevented me twice 
from rege Hungary, but I have seen repeated collec 
