What Geology teaches to demonstration is, that all parts of the dry land have been not once only but many times under the waters of the ocean; but it teaches likewise to demonstration that at least for many and many an age, almost beyond our powers of conceiving duration of time, there has been no total submergence of the land. That interchange of lake and sea with isle and continent which is now going on under our eyes, has been going on for ages innumerable. By this and kindred means human beings, like all kinds of animals and all kinds of plants, have at intervals experienced severance into groups and isolation. Thus has mankind been broken up into distinct families, at first with no line of demarcation except the geographical, but gradually in successive generations becoming more and more unlike in manners, morals, language, features, intelligence, and civilization. But since the era of the Noachian Deluge neither has there been time for Nature, with her slow though certain processes, to effect so great a reconstruction of barriers as to break up the human family, if till then continuous and united; nor, if there had been time for the geographical severance, would there have been time for the constitutional changes. Among the ancients some believed that the sun, moon, and stars were in reality about the size which they appear to the unassisted eyesight; others supposed the vault of the sky to be a revolving dome of solid crystal pierced with little holes through which men saw in starry shapes the fire of the ethereal region beyond it. Persons with such ideas of space and physical science might not readily have accepted on the moment the Copernican system of astronomy. In the same way persons with a narrow and limited view of the duration of time may find a difficulty in receiving arguments based on or implying the enormous extent of it, which all sciences are now combining to demonstrate. But this mental incapacity, the result of false education and early prejudice, may be defied to resist any real investigation of the facts or study of what has been written upon them. Let any man of mature mind and average intellect read through Sir John Lubbock’s ‘Prehistoric Times,’ Mr. Darwin’s ‘Origin of Species,’ and Sir Charles Lyell’s ‘Principles of Geology,’ and retain if he can the opinion that our globe was first peopled about 6000 years ago, and subsequently all but depopulated by an universal Flood. Let him see, indeed, whether he can read Sir Charles Lyell’s account of the progress of opinion and controversy on these subjects and refrain from blushing. He will recognize in that account a turmoil and clamour of fools and philosophers, of laymen and divines. He will have to set to the credit of intelligent humanity and enlightened Christendom a long tissue of pious frauds, jesuitical defences, arguments based on imaginary facts, and facts perverted by imagination, till he comes down to the present