As the principal cause of the colour of mankind, we ought to consider the climate; the effects of nourishment are less upon the colour, yet upon the form they are prodigious. Food which is gross, unwholesome, or badly prepared, produces a degeneracy in the human species; and in all countries where the people are wretchedly fed, they are ugly, and badly shaped. Even in France, the inhabitants of country places are more ugly than those of towns; and I have often remarked, that in villages where poverty and distress were less prevalent, the people were in person more shapely, and in visage less ugly. The air and the soil have also great influence on the form of men, animals, and vegetables. The peasants who live on hilly grounds are more active, nimble, well-shaped, and lively, than those who live in the neighbouring vallies, where the air is thick and unrefined. Horses from Spain or Barbary cannot be perpetuated in France; in the very first generation they degenerate, and by the third or fourth they become downright French horses. So striking is the influence of climate and food upon animals, that the effects of either are well known, and though they are less sudden and less apparent upon men, yet, from analogy, we must conclude they extend to the human species, and that in the varieties we find therein, they plainly manifest themselves. From every circumstance may we obtain a proof, that mankind are not composed of species essentially different from each other; that, on the contrary, there was originally but one species, which, after being multiplied and diffused over the whole surface of the earth, underwent divers changes from the influence of the climate, food, mode of living, epidemical distempers, and the intermixture of individuals, more or less resembling each other; that at first these alterations were less conspicuous, and confined to individuals; that afterwards, from continued action, they formed specific varieties; that these varieties have been perpetuated from generation to generation, in the same manner as deformities and diseases pass from parents to their children, and that in fine, as they were first produced by a concurrence of external and accidental causes, and have been confirmed and rendered permanent by time, and by the continual action of these causes, so it is highly probable that in time they would gradually disappear, or become different from what they at present are, if such causes were no longer to subsist, or if they were in any material point to vary. _END OF THE FOURTH VOLUME._ T. Gillet, Printer, Wild-court. * * * * * Transcriber Note