417 
Geology* 
highest mountains — breaking out to the day, in the well 
chosen phraseology of the miners. Nor is the older gra- 
nite always in its original situation, undermost: it is 
found sometimes overlaying gneiss and other primitive 
strata. Evidently the result of eruptions : taking place, 
not in cavities that occur in or between the layers of the 
crust, but below them all ; for they have all been raised 
Up from the lowest granite, with its superincumbent for- 
mations by some deep seated and mighty force. 
Will it not be allowed, that this force is probably vol- 
canic ? Whence otherwise is it to be derived ? 
Electrical earthquakes have had their day : they will 
occur no more. Nor shall we imitate (I suspect) the Nea- 
politan philosopher who proposed to sink wells to let out 
the steam of the great abyss. I venture to assert it, as a 
theory at least as likely as any other hitherto proposed, 
that volcanoes and earthquakes, are owing to the chemi- 
cal action on each other, of iron, sulphur, moisture and 
atmospheric air. Where are these to be found ? 
All the sulphur of Europe, is supplied by the sublima- 
tion of that substance in the Solfaterras — in the immedi- 
ate vicinity of European volcanoes. 
All lavas contain (on the average) 24 per cent, of 
iron. I think this is the quantity which Kir wan states. 
We have then as volcanic products, sulphur and iron ; 
and if through the lower strata or formations, water 
should be supplied, we have even without atmospheric 
air, all the materials for earthquakes, volcanoes, eruptions 
and subversions. The water is decomposed : the iron 
and sulphur oxygenated : caloric evolved : hydrogen 
escaping through immense cavities inflamed, and all the 
phenomena at once accounted for. 
Having now arrived, per varios casus , per tot discrimina 
rerum* from the nucleus to the crust of the earth, we will 
