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THE ORIGIN OF METEORITES.
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similar to those which now lie around Coon Butte and testify to its former activity. If it had projected those materials aloft with the necessary speed, they might well have been the meteorites which sometimes fall down here to-day.

In conclusion I will just recapitulate the main points of the argument on which we have been engaged in this chapter and the last. I have started from the doctrine put forward by Tschermak, and not, so far as I know, successfully impugned by any other mineralogist, that meteorites have had a volcanic origin on some large celestial body. I have examined the different globes that might possibly be presumed to be the source of the meteorites. I have shown that though the moon may once have been the parent of certain missiles, it cannot be reasonably held to be the source of the meteorites which now fall, inasmuch as the lunar volcanoes are now extinct, and the ejects of the volcanoes of a past epoch must, if they escaped at all, have fallen long ago or shortly after their ejection. I have then brought under review certain of the planets belonging to our system. I have shown how it would be extremely improbable for any missile projected from one of the smaller of these bodies ever to tumble on the earth. I have also shown that the orbits of the small planet are so situated that a very high velocity of projection would be necessary, in order to convey a missile from a volcano there to a resting-place here. I have shown the extreme unlikelihood that any missile discharged from a volcano, on a globe lying somewhere in the stellar distances, could ever reach this earth. I have shown this improbability to be so great, that even though there might be hundreds of millions of

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