The earth is divided into two great continents: and though this division is more ancient than all human structures and monuments, yet man is still older, for he is found the same in both. The Asiatic, the European, and the Negro, propagate alike with the American. Nothing proves more strongly that they have issued from one source than the facility with which they reunite with the common stock. The blood is different, but the germ is the same. The skin, the hair, the features, and the size, have varied, but the internal form has not changed. The type is general and common, and if it should ever happen, by some revolution not to be foreseen, but within the possibility of things, that man should be obliged to forsake those climates which he has possessed himself of, and return to his native country, he would in time resume his original features, his primitive size, and his natural colour. But the mixture of races would produce the same effect in a much shorter time. The conjunction of a white male with a black female, or a black male with a white female, equally produce a mulatto, whose colour is brown, that is, a mixture of black and white. The mulatto intermixing with a white, produces a second mulatto not so brown as the former; and if this second mulatto unites with a white, the third mulatto will have no more than a slight tincture of the brown, which will entirely disappear in succeeding generations. Thus, by this mixture with a white, one hundred and fifty, or two hundred years is sufficient to bleach the skin of the Negro; but it would, perhaps, require many centuries to produce this effect by the influence of climate alone. Since the Negroes were transported to America, which is about two hundred years, not the smallest shade of difference is perceivable in the colour of those families which have preserved themselves from mixture. It is true the climate of South America being hot enough to give the natives a brown tint, we ought not to be astonished that the Negroes retain their colour in that part of the world. Indeed, to make a proper experiment of the change of colour in the human species, some individuals of this black race should be transported from Senegal to Denmark, where the people have generally fair skins, golden locks, and blue eyes; and where the difference of blood, and opposition of colour, are the greatest. We must keep these Negroes with their females apart from the inhabitants, and scrupulously prevent all crossing of their breed. This is the only method of learning how much time it would require to change a Negro into a White, or a White into a Black, by the influence of climate.