Such are the elements of the present population of Europe,—a population which, in its western and southern portions, no longer presents distinct masses of diverse tribes, and whose various sections every century is drawing into closer contact. The progress of commerce and civilisation produces not only an interchange of products of various climes, and of ideas between the various races of mankind, but also a commingling of blood; and as the most nobly developed races are always the great wanderers and conquerors, it will be seen that the progress of the world ever tends to improve the types of mankind by infusing the blood of the superior races into the veins of the inferior. The settlements of the Normans are an instance of this. And a still more remarkable, though exceptional, exemplification of the same thing may at present be witnessed in America—where the Negroes, transported from their native clime, have already become a mixed race, owing to the relation in which all female slaves stand to their masters, and the consequent frequent crossing of the European blood with the blood of Africa. In point of fact, there are slaves to be found in the Southern States, who, like “George” in _Uncle Tom’s Cabin_, are as Caucasian in their features and intellect as their masters,—a circumstance fraught with considerable danger to the White caste in these States, because producing the extremest irritation in these nearly full-blood “white slaves,” and at the same time providing able and fiery leaders for the oppressed Negro race in the event of an insurrection and servile war.