It has been said a day will come when the Polar ice shall have accumulated, till it forms vast continents many thousands of feet above the level of the sea, all of solid ice. The weight of this mass will, it is believed, cause the world to topple over on its axis, so that the earth will be upset as an ant-heap overturned by a ploughshare. In that day the icebergs will come crunching against our proudest cities, razing them from off the face of the earth as though they were made of rotten blotting-paper. There is no respect now of Handel nor of Shakespeare; the works of Rembrandt and Bellini fossilise at the bottom of the sea. Grace, beauty, and wit, all that is precious in music, literature, and art--all gone. In the morning there was Europe. In the evening there are no more populous cities nor busy hum of men, but a sea of jagged ice, a lurid sunset, and the doom of many ages. Then shall a scared remnant escape in places, and settle upon the changed continent when the waters have subsided--a simple people, busy hunting shellfish on the drying ocean beds, and with little time for introspection; yet they can read and write and sum, for by that time these accomplishments will have become universal, and will be acquired as easily as we now learn to talk; but they do so as a matter of course, and without self-consciousness. Also they make the simpler kinds of machinery too easily to be able to follow their own operations--the manner of their own apprenticeship being to them as a buried city. May we not imagine that, after the lapse of another ten thousand years or so, some one of them may again become cursed with lust of introspection, and a second Harvey may astonish the world by discovering that it can read and write, and that steam-engines do not grow, but are made? It may be safely prophesied that he will die a martyr, and be honoured in the fourth generation. PERSONAL IDENTITY. (CHAPTER V. OF LIFE AND HABIT.) "Strange difficulties have been raised by some," says Bishop Butler, "concerning personal identity, or the sameness of living agents as implied in the notion of our existing now and hereafter, or indeed in any two consecutive moments." But in truth it is not easy to see the strangeness of the difficulty, if the words either "personal" or "identity" are used in any strictness.