Let us now then enquire why, in this new world, the reptiles and insects are so large, the quadrupeds so small, and the men so cold. These effects must depend on the quality of the earth and atmosphere, on the degrees of heat and moisture, on the situation and height of mountains, on the quality of running and stagnate waters, on the extent of forests, and, in a word, on the state in which inanimate nature presents itself in that country. In the new world there is much less heat and more moisture than in the old. If we compare the heat and cold, in each degree of latitude, we shall find a very great difference; that at Quebec, which is under the same degree of latitude as Paris, the rivers are covered with ice for months in the year, and the grounds with snow several feet thick; the air, indeed, is so cold, that the birds fly off at the approach of winter, and return not till invited by the warmth of spring. This difference of heat under the same latitude in the Temperate Zone, though considerable, is perhaps less so than the difference of that under the Torrid Zone. At Senegal, we are scorched, while at Peru, situate under the same line, we enjoy the benign influence of a temperate climate. In such a situation is the continent of America placed, and so formed, that every thing concurs to diminish the action of heat. There we find the highest mountains and greatest rivers in the known world; these mountains form a chain which seems to terminate the length of the continent towards the west, while the plains and low grounds are all situated on this side of the mountains, from whose base they extend to the sea, which separates the American from the European continents. Thus the east wind, which constantly blows between the tropics, does not reach America until it has traversed a vast extent of ocean, and has consequently been greatly cooled; and for this reason it is much less warm at Brasil and Cayenne, for example, than at Senegal and Guinea, where this east wind arrives, charged with the heat of all the burning sands and desarts which it necessarily passes in traversing both Asia and Africa.