In this state they would remain buried deep under the superincumbent oxidated crust of the earth, until water and air should find access to them. When this should take place a rapid, and extensive _chemical action_ would commence, generating immense quantities of hydrogen gas, the metals _decomposing_ the air and water, in the process of oxidation, and setting the _hydrogen_ of the water, and _nitrogen_ of the air _free_. Thus a large amount of the most inflammable of all gases would be disengaged. The rapid chemical action would _raise the temperature_ of these gases, and thus _increase their bulk_ immensely, which would produce an irresistible _expansive force_, which would _increase the pressure_ against the sides of the cavern in which the gases were generated, _and the_ IGNITION _of the hydrogen would be a necessary consequence_. Such an immense volume of gas being ignited, and confined, would produce such a degree of heat, as rapidly to _decompose_ or _melt_ the substances in its neighborhood, and set at liberty a vast quantity of other gases; all of which being _ignited_, and of course _expanded_ immeasurably, would not only shake a given section of the earth, but, if placed in its centre, would shake the solid globe throughout, and rend it into ten thousand pieces, if it did not find means to escape. If it found means of escape by some opening forced from its seat to the surface of the earth, _that opening would_ CONSTITUTE A VOLCANO; from which the gases would escape, and throw out before them the vast amount of volcanic products which are known to come forth of the craters. It now remains to inquire, _whether a sufficient quantity of water can be supposed to have access to these metals_? From what we know of the distribution of water generally in the bowels of the earth, we should have no difficulty in admitting the _affirmative_. But this question may be clearly answered by two circumstances. First: Large quantities of boiling water and mud, are frequently ejected from volcanos. This proves an _excess_ of water at, or near the seat of action, which could not be decomposed, before the amount of gases generated, and acting with incredible force, drove it out of the crater. This fact is true in some measure of all volcanos, but eminently so of those in South America. “Bouguer and Condamine saw these formidable torrents tear up the surface of a whole country. Six hours after an explosion of Cotopaxi, a village nearly eighty miles distant in a straight line, and probably one hundred and forty by the winding channel, was entirely swept away by the flood.” _Ure’s New Sys. Geol._ p. 386.