shortly after it had attained a solid exterior, but while its internal fervour was more vigorous than it is at present? I have pointed out, that though a great column of gases and vapours, projected vertically from a volcano, may be exposed to tremendous atmospheric resistance at its exterior, it may yet contain missiles in its interior whose movements are but little interfered with. In illustration of this I cited the well-known fact, that notwithstanding the resistance of the solar atmosphere, metallic vapours are often projected through it, with prodigious velocity, to an altitude of scores of thousands of miles. Lastly, I have dealt with the argument that may be derived from the fact that the minerals at present most abundant on our earth are not those which come down in meteorites. It has, however, been demonstrated, both at Ovifak and at Coon Butte, that the iron-nickel alloy, which is above all other substances most characteristic of meteoritic masses, is a terrestrial mineral. It has been found in the two places I have named, under such circumstances as to prove that it must have been extruded from the earth's interior. It therefore seems that there can be no doctrine, with regard to the source of meteorites, which has the same probability in its favour as that which assigns to them an origin in volcanoes in a primeval condition of the earth.
