"The mind of men became sharpened in order to comprehend the boundless store of new phenomena, to work them out, and by comparison to employ them for the attainment of general and higher views of the creation. If we carefully examine the original works of the earliest historians of the _Conquista_, we are astonished at finding, in a Spanish author of the sixteenth century, the germs of so many important physical truths. Upon the occasion of the discovery of a continent, which appeared to be separated from all the other regions of the creation, in the distant solitude of the ocean, a great number of the same questions with which we are employed at the present day occurred to the excited curiosity of the travelers, and to those who were collected together by their narratives; these questions were, Of the unity of the human race, and the derivation of its varieties from a common original form; of the migration of nations, and the affinities of language; of the possibility of varieties in the species of plants and animals; of the causes of the trade winds, and of the constant currents in the ocean; of the regular decrease of temperature at the declivities of the Cordilleras, and in the various strata of water at different depths of the ocean; and of the respective effects of chains of volcanic mountains, and their influence upon the frequency of earthquakes, and the extension of the range of the volcanic forces. The foundation of what is at the present day called physical geography is, exclusive of mathematical considerations, found in the works of the Jesuit, Joseph Acosta, and in the work of Oviedo, which appeared scarcely twenty years after the death of Columbus. In no other period of time since the existence of man in a social condition has the range of ideas in respect to the external world, and the relations of different places, been so suddenly and so wonderfully extended, or the necessity of observing natural phenomena in different latitudes and at different elevations above the level of the sea, or of multiplying the means of examining them, so deeply felt."--Humboldt's _Cosmos_, vol. ii., p. 295-337. No. XII.