of Oriental history will assent to the unsupported doctrine, that the intensity of the climate of tropical countries affects the intellectual status of races.  If any one be so prejudiced as to doubt this, let him turn to “Asiatic Researches,” and learn that the dark races have made some of the most invaluable contributions to science, literature, civil-engineering, art, and architecture that the world has yet known.  Here we find the cradle of civilization, ancient and remote.

Even changes and differences in color are to be noted in almost every community.

“As we go westward we observe the light color predominating over the dark; and then, again, when we come within the influence of damp from the sea-air, we find the shade deepened into the general blackness of the coast population.”

The artisan and farm-laborer may become exceedingly dark from exposure, and the sailor is frequently so affected by the weather that it is next to impossible to tell his nationality.

“It is well known that the Biscayan women are a shining white, the inhabitants of Granada on the contrary dark, to such an extent, that, in this region, the pictures of the blessed Virgin and other saints are painted of the same color."[55]

The same writer calls attention to the fact, that the people on the Cordilleras, who live under the mountains towards the west, and are, therefore, exposed to the Pacific Ocean, are quite, or nearly, as fair in complexion as the Europeans; whereas, on the contrary, the inhabitants of the opposite side, exposed to the burning sun and scorching winds, are copper-colored.  Of this theory of climateric influence we shall say more farther on.

It is held by some eminent physicians in Europe and America, that the color of the skin depends upon substances external to the cutis vera.  Outside of the cutis are certain layers of a substance various in consistence, and scarcely perceptible:  here is the home and seat of color; and these may be regarded as secretions from the vessels of the cutis.  The dark color of the Negro principally depends on the substance interposed between the true skin and the scarf-skin.  This substance presents different appearances:  and it is described sometimes as a sort of organized network or reticular tissue; at others, as a mere mucous or slimy layer; and it is odd that these somewhat incompatible ideas are both conveyed by the term reticulum mucosum given to the intermediate portion of the skin by its orignal discoverer, Malpighi.  There is, no doubt, something plausible in all the theories advanced as to the color and hair of the Negro; but it is verily all speculation.  One theory is about as valuable as another.