76 REPORT—1850.. 
quently alludes to “their upheaving or depressing force,” and to land 
elevated by them (Principles of Geol. pp. 431, 433, 435, 439, 689); but 
whatever be the ultimate nature of the elevatory and depressive forces to 
which earthquakes are due when in action, these forces manifest themselves 
to us in the reaction of the inner portions of our planet, acting through their 
exalted temperatures upon its outer crust. The term volcanic fire has been 
so long used, and so loosely, and become so habitual, that its abuse has pro- 
duced in almost every mind, a conception of chemical interchange of ele- 
ments, of fire in its popular sense, in which something enters into combination 
with something else and burns with a true combustion (like that of a metal 
in chlorine, or of coal or wood in the air), as a true representation of 
the heat of the inner portions of the earth, the external manifestations of 
which we behold in the voleano. Yet nothing probably can be further 
from the truth; the main phenomena of volcanic action, so far as we 
know them, are those of ignition, up to liquefaction of solid bodies incapable 
of any combustion; nor is there any evidence of this ignition being produced 
or maintained by the consumption of a fuel, 7.e. by chemical combination, 
in which a body, or part of a body, before solid, becomes gaseous. 
For as the explosive energy shown in volcanic eruptions is but the by- 
play, and not of the same nature with the enormous and quietly-acting force 
by whose (hydrostatic) action from beneath the great elevations are effected, 
so are the local evidences of combustion at the crater of the volcano, but the 
by-play also, and not of the nature of that rise of temperature up to ignition 
without the consumption of a fuel, which is the main phenomenon. 
In a word, let us not be dazzled by the glare of the volcano itself, grand, 
and to us vast, as may seem its forces and their phenomena, so as to confound 
these, the true combustions, gaseous explosions, and all the other superficial 
actions at the crater, with the mighty and quietly-acting forces deep below, 
of which these are all but symptoms, and perhaps as slight ones, as some 
cutaneous disorders are of deep-seated and all-pervading inflammatory 
action in the human frame. 
This error is not fallen into by the greater observers amongst continental 
cosmologists: hear Von Hoff (Gesch. Veran. Erdober, Th. iv.) :— 
“In the great mountain-chains of Europe there exists at present no vol- 
canic energy. It seems to have ended by the great act of the upheaving of 
these mountains, and since then to have been turned into other channels. 
“‘ The same seems to be true, at least for the most part, with respect to 
the mountains of Asia. Only some portions of the Andes are remarkable as 
being continually affected by volcanic eruptions. Such are parts of Chili, 
Quito, and Guatemala. Here we cannot avoid making the remark, that the 
Andes pass along and close to the great Pacific ocean, whereas the great chains 
of mountains of Europe and Asia constitute the inmost centre of great conti- 
nents, whose whole condition of surface has been determined by them. This 
is especially true with respect to Asia, and perhaps this want of volcanic 
openings has been the reason of the upheaval of such a large extent of land. 
“‘ These volcanic springs are the outlets for the violent efforts of the sub- 
terranean vulcanismal processes; and it is remarkable that in countries where 
there are these outlets, and especially where they exist in large numbers, the 
inner forces never increase sufficiently in strength to upheave large tracts of 
land, or to alter the character of the sea-bottom, whilst in places where 
these outlets for the vapours and gases produced by the subterranean pro- 
cesses are wanting, their concentrated force is able to upheave whole coun- 
tries. Hence probably the neighbourhood of the sea to the most active vol- 
canoes, of which by far the greater number are found on coasts and islands. 
