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 manner the way in which the iron graduates into the adjacent minerals.

A meteoritic origin of these masses would be only possible on a wholly preposterous hypothesis. To account for them on such a theory we should have to suppose that at a time when molten lava was poured forth from a volcano or was welling upwards from the earth's interior to the surface, it so happened that an unparalleled fall of tremendous iron meteorites plumped down from the sky just into that particular spot which the lava occupied. We need not entertain a supposition so widely improbable. It is perfectly plain that the Ovifak irons have not come down from above. We must adopt the other alternative that they have come out with the basalt from the interior of the earth.

This is a conclusion of an extremely instructive character. We may note that it derives confirmation from the discovery of Andrews that metallic iron, though no doubt in minute particles, was a constituent in some specimens of basalt obtained in the north of Ireland. Other circumstances corroborate the notion that iron is extremely abundant in the interior of the earth. The phenomena of terrestrial magnetism indicate that this element must be an important constituent in the earth's interior. The argument derived from the density of the earth also deserves notice. It has been established that the mean density of our globe is upwards of five times that of water. But even the heaviest rocks which lie on the earth's surface have a density scarcely three times that of water. Of course it must be admitted that the materials in the centre of the earth are exposed to prodigious pressure, but yet there is nothing we know as