centuries previous there had been an immense and almost continuous emigration from Asia, not of individuals, as we witness in the present day, to America, but of tribes, communities, whole nations. History is indeed imperfect, if not altogether silent, in respect to the cause of these mighty migrations which so long pressed upon Europe. But there can be little doubt that the Mongolian race about this time changed, to a considerable extent, its location, and pressing down on the old Caucasian populations of Asia, impelled those vast masses to seek shelter and safety, if not homes and happiness, in Europe. In the mighty invasions of Italy in the fifth century by Attila, the truth of this is certainly demonstrated. He himself was doubtless a white man, and so were his chiefs; but the mighty populations he ruled over, and which extended from the Danube to the frontiers of China, were mainly Mongolian. But no Mongolians settled permanently in Europe—none but Caucasians, and except the modern Turks, none but pure Caucasians—and, being the same men as the Romans themselves, why should they be barbarians? They were conquerors; a pretty good proof that, though not so refined perhaps, certainly not so effeminate as the Romans had become, they could not have been barbarians. Other things being equal, the nation that has made the greatest advance in knowledge will be able to conquer, because it has only to apply its knowledge to this object to succeed. There can be no doubt that we ourselves surpass all the nations of our times in knowledge, or in our capacity to apply our knowledge to the purposes of material existence. Our railroads, canals, public works, our ship-building, commerce, etc., prove this, and we have only to apply this knowledge to purposes of offence or defence, to invade others or to defend ourselves, to demonstrate our immense superiority. Nevertheless, if we should conquer Spain, or any other ancient and effete empire, doubtless their writers would take their revenge in calling us barbarians, as indeed the poor, feeble, and adulterated hybrids of Mexico actually did thus represent us when in possession of their capital. Nothing, therefore, can be more improbable than the theory of Gibbon and others, that the nations that conquered Rome were barbarians, and that the dark ages were the result of that conquest. But there was a cause for the subsequent darkness which so long spread over the European world much more palpable. Christianity had become generally accepted, and bad and ambitious men, in the then general ignorance of the masses of the populations, might wield it with stupendous effect in advancing their ambition and securing their own personal objects. The assumption that Christ had delegated a power on earth to interpret the will of Heaven, both as to temporal as well as religious interests, was enough; of course all human investigation and mental activity terminated, and was denounced as impiety.