But, on the whole, these true Deserts offer ample material for the admiration of the artist, the meditations of the thinker, the researches of the naturalist and the physician. Theirs is that kind of beauty which borders on the sublime, and which impresses us so powerfully in the Ocean. And, like the Ocean, they awake in the soul the feeling of infinity. They render it forgetful of the tumultuous regions which are perturbed by petty passions, and vexed by the contentions of ephemeral interests, and transport it to the boundless space and the eternal spheres, or allow it to draw back within itself and muse upon its future destiny. Finally, what grave problems does the Desert place before the man of science! And first, why do life and fertility prevail elsewhere,--here, sterility and death? Why does an irrevocable curse seem to weigh upon certain parts of the world, while others rejoice in Nature's fairest gifts? It is by examining the constitution of the soil and the character of the climate that we discover the key to this enigma, and recognize in this apparent anomaly a necessary effect of the harmonious laws of the universe. Then the Desert has a geology and a meteorology of its own; is the theatre of special phenomena, which we do not observe in more favoured regions. Life itself is not completely absent from it; specimens of the organic kingdoms are rare, no doubt, but for this very reason are the more interesting. And if, from the Desert properly so called, we pass to those countries where the genial air and the abundant waters favour the action of the productive forces, the interest increases with the increasing development of life. The picture changes every moment, and every moment grows more animated. The scenes of the savage world unfold before our eyes like a moving panorama; unexpected incidents and dramatic episodes multiply one upon another. Every region appears before us with its primitive aspect, its grand and picturesque landscapes, its characteristic fauna and flora--frequently, also, with its tribes of white, or tawny, or black, or copper-coloured men, whose singular manners, brutal instincts, fierce passions, and wretched condition offer, in all its mournful reality, the spectacle of that "state of nature" celebrated by a great writer as the ideal of virtue and happiness. * * * * *