ALEXANDER VON HUMBOLDT is one of the most respectable names in the annals of natural science. Respectable is the term; but respectable in the highest sense. An ardent student of nature for fifty to sixty years, with opportunities, moreover, as rare as his inclinations, he can scarce be cited as the discoverer of a single one of her leading laws. He has written, too, as well as thought upon her in every aspect; written, perhaps, all that he has thought. And all that he has written he seems to have given to the world, in every mode of publication-from the academical memoir up to the illustrated folio. Yet, the utmost a general judgment may honestly award him, is this: that he has written always intelligently, often instructively, never profoundly. It is a high eulogy, no doubt; high, especially in an age when, under the pretext of popularity, literature is vulgarized to clap-trap, and science degraded to quackery. But was it all that might be expected from an intellect at whose service the gods seem to have vied to place every external advantage. Was it all that might have been accomplished by the sixty years' labor of a man commencing his career with a competent education and a Teutonic frame; prosecuting it throughout without interruption by sickness, without distraction by family, without disturbance by passions; personally visiting nature in all her contrasts of appearance; witnessing man in all his conditions of civilization; in fine, the companion or correspondent of the mental elect of the age; the protected of kings; and, above all, the possessor from the outset of an independent private fortune?

Yet it may well be that most of these circumstances have rather contributed to propagate his fame than to fit him to deserve it better. Dr. Johnson thought a man of rank who descended to even the congenially idle exertion of writing poetry,

ought to be handsomly commended. How much larger then should be the obligation when he submits to the duress of fact, to the drudgery of science? Then the absence in Humboldt of the stronger passions, as well as of the originative power of genius, naturally conduce to the same partiality of appreciation among the learned. He has, in fact, had no enemies, for the same reason that he has had no followers. He is one of those irreproachable mediocrities which, in philosophy as in society, you hear everybody praise, because they have not force enough to scorn the pretenders or to rival the truly great. They thus escape condemnation, between critics and competitors, as the bat escaped conscription in the battle of the beasts and birds. Not only this, but they ordinarily receive the ostentatious panegyrics of the former, and the patronising compliments of the other. And both go alike to inflame the sympathetic predilection of the general public for the average order of intellect. Hence we see Humboldt addressed familiarly by speculators in canals or railroads; and ship-owners presume to honor him by marking their water-wagons of trade with his name. This might be a compliment to an Astor or even a Baring; but who would think of thus complimenting the name of a Bacon, a Gallileo, or Napoleon?

Most

Besides, and, perhaps, above all the preceding elements in the aggregated reputation of Humboldt as a philosopher, was, at least in the eyes or the echo of the multitude, his pecuniary independence. men, feeling unwilling to toil themselves, unless for money, are apt to reason upon the matter somewhat in this wise: Here is a man with ample wealth, political distinction, and court honors at his command, and who perseveringly foregoes all for the hardships of a wandering, often the privations of a savage life. What other could be the motive of a course so uncommon than the

The origin of this complete sterility is aseribed by Humboldt to an irruption of the ocean, in this case, the Atlantic, which tore away not only the primeval vegetation, but the very soil itself, from the surface of the earth, and then, on retiring, left the desolated region overspread with a suffocating plain of sand. The barrenness thus produced, which was originally common to all the species of desert, is perpetuated in that of Africa by its position in the torrid zone. There can be no vegetation, no development of organic life, without moisture. But neither rain nor dew is permitted to light within the parched precincts of the Lybian sands. The rays of the vertical sun reflected with accumulating intensity from the bare and burning plain, have the effect of rarifying the atmosphere so as to send it upwards in perpendicular columns, that dissolve the gathering vapors, and devour the rushing clouds on their way. By this natural ascension of the rarified air in the direction of the lighter pressure, our author also explains some other curious phenomena. It had been long remarked that summer insects were frequently met with up the sides of tropical mountains beyond the region of perpetual snow. Humboldt himself observed even butterflies on the summit of Chimborazo. It was certain they would never have entered a climate so fatally uncongenial of their own will or instinct. The solution was, then, that they had been floated thither forcibly by the atmospheric current from the scorching plain below. Another singular fact was the deviation from the trade winds experienced along the Atlantic in front of the African coast, particularly between the Canary and Cape Verde Islands. It was the cool ocean air rushing landward towards the Sahara desert. And thus this wind, long so perverse to the philosopher, as well as still adverse to the mariner bound for the New World, had its mysterious cause many thousand of miles away, in a quite opposite direction. The cause was no other than the African desert in its peculiar aridity and extent, which produce, by the expansion described, an enormous and insatiable gulph in the equilibrium of the atmosphere ocean.

But why is the aridity thus peculiar to Africa? The LLANOS on the opposite continent of South America, is equally within

VOL. V. NO. II. NEW SERIES.

the tropical regions, yet they are visited by both dews and rains, and present accordingly a degree of vegetation which lasts a large portion of the year. This can be owing but to a difference of climate or soil, the latter, of course, including the configuration of the country. The destructive characteristics, in these particulars, of the western desert, are enumerated by Humbolt as follows:-"The comparatively limited breadth of this continent, (South America), intersected in a thousand ways throughout the equinoctial regions to the north of the equator; its prolongation towards the icy poles; the ocean, with its unbroken surface, swept over by the trade winds; the flatness of the eastern coast; the currents of very cold water which wash the western, from the Straits of Magellan along to Peru; the numerous chains of mountains cooled all over with springs, and whose snow-covered summits soar beyond the region of the clouds; the abundance of immense rivers which, through multiplied meanderings, are observed to always seek their outlet at the remotest point of the coast; the deserts without sand, and consequently less susceptible of being impregnated with heat; the forests of impenetrable thickness, which cover the plains of the equator, watered underneath with a multitude of streams, and which, in the parts of the country more remote from the ocean and the mountains, give rise to enormous masses of water, that are either the product of their confluence or the result of the luxuriant vegetationall these causes combine to produce, in the lower parts of the American continent, a climate contrasting singularly, in coolness and humidity, with the temperature of Africa. To these alone should we attribute also that vegetation so vigorous, so luxuriant, so sapful, and that foliage so copious, which constitute the special character of the New World."

The consequence of this state of the climate upon the South American desert is the production of an abundant crop of grass during the favorable season of the year. With the annual return of the drought, however, the Llanos assumes the condition of the Sahara in all except the sand. This dreary metamorphosis begins with the sudden burning of the tall grass into dust, the opening of the plain into

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deep fissures as if cracked by an earthquake. Then, if cross winds should come into collision at the surface and the conflict result in a circular motion, the dust, says the author, is whirled aloft in moving columns, like the water-spout. The heavens, overcast, shed but a murky and livid light upon the desolate plain. The horizon, before unbounded, is suddenly curtained round, contracting the area of the desert and the heart of the spectator. The burning dust which surcharges the atmosphere intensifies, by reflecting, the stifling heat of the air. And the easterly winds do but augment instead of allaying it, by accumulating the emanations of the sweltering soil. The verdure of even the palm-tree withers, and the pools of water which it protected run gradually dry. As the animals of northern regions are found to wrap themselves in the ice, so the crocodile and boa take refuge here from the opposite affliction by burying themselves in a like torpor as deep as practicable beneath the arid earth. Blinded with clouds of dust, goaded with hunger, and parched with burning thirst, the cattle and horses are seen to wander about, the former uttering hoarse and mournful lowings, the latter, with outstretched necks, directed to windward, snuffing strongly the air to discover, by the moisture of its current, the vicinity of some water-pool not yet entirely evaporated. The mules, more sagacious, take another means of assuaging their thirst. They seek out the melo-cactus, a vegetable of a spherical shape, and containing under a prickly rind a substance of a very watery character. The mule, after removing the thorns by means of its fore feet, applies the lips with caution, and sucks the refreshing juice. But it is sometimes at the cost of a string-halt, with which these animals are frequently maimed by the prickles of the cactus. Another species of prickles pursues these creatures in general by night, and denies them the alleviation of repose. During sleep they are set upon by shoals of monstrous bats, that fasten upon their backs and suck the blood like vampires, and, moreover, leave them all scarred with putrescent sores, upon which settle in turn succeeding swarms of horse-flies, mosquitoes, and a multitude of other sting-bearing insects. Such is the wretched existence of these animals during the season of drought.

But the condition of some of them is scarce improved by the inundating rains. The face of nature indeed is freshened. The desert buds anew with the lank blades of its grasses. The aquatic vegetables throw open their flowers. The earth is seen to rise here and there into hillocks, whence issues at last with a bubble-bursting explosion, some huge water-snake or cuirassed crocodile from its temporary tomb. The birds sing, the horses and cattle bound for joy. But the delight of the latter is soon turned into a new distress. Not only is their pasture submerged by the rising waters, but, insulated upon the elevated spots to which they had gradually retired from the advancing flood, they are penned up into close company with the jaguar and the crocodile. But they have still a more fatal, because unknown, enemy in the waters. This enemy is the electric eel, against whose nervous battery the most powerful animals would defend themselves in vain. The method of catching this singular fish, which man can neither hook nor even strike with impunity, is worth citing in the lively description of our author:-"The fishery of the electric eels affords a picturesque spectacle. In a marsh or pool which is first surrounded by a close circle of Indians, a troop of mules and horses is made to run about, until the strange noise brings these spirited fishes to the attack. Then you see them float like serpents on the surface of the water, and press themselves adroitly against the bellies of the horses. Several of the latter drop lifeless by dint of the invisible blow. Others exhausted, palpitating, with mane erect, and eyes haggard, sparkling, and expressive of intense anguish, attempt to evade the suffering by quitting the place. But the Indians, armed with long bamboo canes, repulse them into the water. Gradually the impetuosity of the unequal combat declines. The eels, at last fatigued, disperse about the pool. They need long repose and abundant nutriment to repair their expenditure of galvanic energy. Their shocks more and more feeble produce commotions less effective. Scared by the splashing of the horses, they timorously approach the bank; here they are struck with harpoons, and then drawn up upon the desert-sward by means of sticks well dried and non conductive of the fluid."

Such is the singular battle of the horses and fishes. Though a veritable fact, it is, perhaps, more poetical than the fabled "battle of the frogs and mice." Humboldt adds this philosophic reflection:-That which constitutes the living and invisible weapon of these dwellers of the watery element; that which, developed by the contact of humid and heterogeneous parts, circulates through the organs of all animals and vegetables; that which kindles through the storm the firmament of heaven; that which attracts iron to iron, and determines the tranquil and retrograde veering of the magnetic needle-all this, is derived from one and the same source, like the diversified colors of a refracted sunbeam. All these forces have their fountain in the universal and eternal energy, which animates the organizations of nature and governs the motions of the stars.

The third species of desert is the STEPPE; of which the principal sample belongs to Central Asia. Here it takes the character of an immense table-land, stretching along the backs of the enormous congeries of mountains .which cover a large portion of that continent. These steppes are therefore the most elevated, and they are also the most extensive in the world. They are estimated to contain 160,000 square leagues, and rise some 8 or 9,000 feet above the level of the sea. They extend from the 30th to the 50th degree of latitude north, and lie therefore mostly within the temperate zone. Accordingly, the plains are some of them clothed with the finer grasses; others are adorned with saline plants perpetually green, vigorous, and pointed. "A large number shine at a distance with muriatic efflorescences, which crystallize in the shape of lichens, and cover the clayey soil with scattered spots not unlike to new-fallen snow."

But there is another production of this Asiatic modification of the desert, of a nature which should perhaps lead humanity to wish it had been as inhospitable as the African. These steppes have been the "northern line" of the oriental world; the source whence have issued all those nomad hordes of barbarians who have extinguished or retarded civilization at successive periods of history, from the shepherds of ancient Egypt to the sultans of modern Greece. Here also the Huns, Alans, and more or

less immediately, the Vandals, Goths, &c., who carried their devastations into the heart, and even to the utmost extremeties of Europe. And this long series of disasters, with which the world is perhaps not yet done, seems due to the existence in northern Asia of those immense regions of land at once incapable of agriculture, yet affording pasture to flocks enough to feed a vast population in that idle and adventurous mode of life called the shepherd state. For this is not a stage of transition alone. It may, we think, become nent by necessity, as in this instance. necessity perhaps imposed, not so much by the pre-occupancy of the arable countries, as by the correlation that long subsists between the moral condition of communities and the physical character of the region of earth upon which they chance to have been cast.

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How otherwise account for the persistence in the shepherd state of the Arabs of the desert," whose ancestry had been semi-civilized and agricultural when Europe was still a wilderness? The same principle would perhaps help to explain a circumstance noted by Humboldt, but which he does not attempt to reconcile with the prevailing theory, though citing the latter with undoubting assent. striking fact-if it be a fact is this, that the "shepherd state" has never existed upon the American continent. The North was still savage, the South agricultural, and the latter had no traditions of having passed through such a stage. The alleged fact is, we say, striking at first, because it is contrary to the current hypothesis upon the subject. But if it were asked to name the country of Europe, for example, which is known to have passed through this mode of life in its characteristic acceptation, one would be surprised to find perhaps that, with all the advantages of historical record, the absence or the oblivion of the matter is here no less complete than in the instances of Mexico and Peru. Was there ever, in short, a country, originally well wooded, and thus adapted to agriculture, where, after reclaiming it, the community derived its sole sustenance from milk and cheese? Is it not, on the other hand, in those regions of the earth where the vegetation, starved back to its primary stage of the coarse grasses, announces the hopelessness