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 profitably cultivated The soil is in many places strongly impregnated with the muriate pf soda, and in others it abounds with asphaltum, by which it is rendered too compact, especially during the excessive heats of the dry season, for tillage. The experiment has been tried on these soils, with fruit trees and esculent roots, and has repeatedly failed. Thus the apple and the potato have both been introduced, and to both the prairie has been found uncongenial, although they both flourish in the hilly region, and near the seashore. My belief is that these prairies are the results of ancient volcanic action, in which respect they do not differ from all the rest of that territory. But while the conformation of the hilly country, has aided the efforts of nature, by rains, and dews, and streams of water, to carry off these salts and other elements which are unfriendly to vegetation, and hasten the return of fertility and productiveness, the level prairie has advanced much more slowly in the same direction, retaining for ages, in defiance of the tardy process of leaching and infiltration, vast quantities of mineral substance, destructive to vegetable life. Without the aids of agricultural science, centuries more must elapse before the pure waters of the skies shall wash out from the soil of the prairie these poisonous relics of that awful convulsion of nature which, in ages far beyond human tradition, overwhelmed the western shores of our continent. Immediately along the banks of the rivers by which the prairie is intersected, as if to [49] demonstrate the correctness of my hypothesis, there is always found a strip of the choicest alluvion.

The seasons of this country are two—the wet and the dry. The wet or winter season extends from November to March, covering about five months of the year. During this period it rains without cessation for many days or weeks together; and during the rest of the year the rain seldom or never falls, and nothing but the heavy dews of the short summer nights relieves the fiery monotony of those seven long months. By the abundant waters of the rainy season, immense tracts of