BOOKS.

IIIIMBOLDT'S ASPECTS OF NATURE,.

A PORTION of this work appeared nearly half a century ago, soon after Humboldt returned from America, when the grandeur, the magnificence, and the wonders of Transatlantic nature, were fresh upon his mind. in 1826 a new edition was published by the author; in which he inserted two new papers, and revised the whole, with additions to the notes and illustrations. An expedition to the Ural and Altai Mountains in 1829, by command of the Emperor of Russia, says M. Humboldt, "falls between the publication of the second and third editions. This expedition has contri- buted materially to the enlargement of my views in all that regards the form of the surface of the earth, the direction of mountain chains, the connexion of steppes and deserts with each other, and the geographical distribution of plants in relation to ascertained conditions of temperature." These larger views were embodied in this third edition, prepared by the author in his eightieth year, together with a variety of facts and conclu- sions, which the observations of travellers and the deductions of philoso- phers are continually adding to science.

The book now consists of seven papers ; four of which relate to the

" aspects of nature" as they appear in South America ; a fifth treats of the physiognomy of plants, in which American and Tropical vegetation occupies a conspicuous place; a sixth is on the structure and mode of ac- tion of volcanoes in different parts of the globe ; the seventh is a species of allegory, called " The Vital Force, or the Rhodian Genius." It is an ef- fusion of the author's youth ; and endeavours to inculcate, though not v clearly and still less conclusively, what were his ideas of that very difficult subject. To the facts or opinions of the text notes are added, under the title of "Elucidations." They are numbered like the references to annotations upon the text of an historical narrative ; they sometimes considerably exceed the text in length, as in the illustrations to the paper on Steppes and Deserts, which are upwards of fifty in number and occupy nearly four times the space of the paper they elucidate. They, of course, are very various in subject. They embrace questions as extensive as the peopling and civilization of America, down to some particular point connected with a plant or animal ; while their character changes from that of a mere note, to an essay on some important subject.

The principal end in five at least of the treatises, is to present the general idea and the more singular features of some great natural subject, connecting it at the same time with other natural objects throughout the world ; the plains, mountains, volcanoes, rivers, animals, and phrenomena of some particular continent, being passed before the reader, illustrated by similar aspects of nature in other regions. Description, mingled with discussion on topics inclining to the abstruse, is apt to become rather fa- tiguing, even when occasionally enlivened by incidents of travelling or autobiographiCal reminiscences that derive interest from the celebrity of their author; and to the unscientific reader these volumes will not always be found free from heaviness. But it is a remarkable work ; com- bining in a rare manner the lofty and all-comprehensive imagination of the poet with the precise knowledge and minute accuracy of the man of sci- ence. The vastest and grandest objects in nature are brought before the mind in all their extent and magnificence ; things stranger " than poets yet have feigned or fear conceived" are presented, not with didactic dryness, but poetical richness and artistic effect ; and truth is felt to be not only " stranger " but stronger "than fiction." Nor is Humboldt limited by the scene before him however large : all that it has in common with cognate subjects throughout the globe are brought together to enforce the principle, to impress the outward form, and to enrich the composition; while all that is peculiar to the region is exhibited in more or less of de- tail. These characteristics, which prevail through all the six papers, (for the Rhodian Genius has little in common with the others,) are most strikingly exhibited in the treatise on Steppes and Deserts ; where, after painting with a few free strokes the Pampas of South America, the masterly author presents the leading features of the great Desert of Africa, the Steppes of Tartary, and the plains of Northern Europe, it where the Heaths, which, covered with a single race of plants repelling all others, extend from the point of Jutland to the mouth of the Scheldt, may be re- garded as the Steppes, but steppes of small extent." The various and striking features peculiar to the Pampas are then successively displayed ; as in this picture of the dry season. " When, under the vertical rays of the never-clouded sun, the carbonized turfy covering falls into dust, the indurated soil cracks asunder as if from the shock of an earthquake. If at such times two opposing currents of air whose conflict pro- duces a rotatory motion come in contact with the soil, the plain assumes a strange and singular aspect. Like conical-shaped clouds, the points of which descend to the earth, the sand rises through the ratified air in the electrically-charged centre of the whirling current, resembling the loud water-spout dreaded by the expenencel mariner. The lowering sky sheds a dim almost straw-coloured light on the deso- late plain. The horizon draws suddenly nearer ; the steppe seems to contract, and with it the heart of the wanderer. The hot dusty particles which fill the air increase its suffocating heat ; and the East wind, blowing over the long-bested soil, brings with it no refreshment, but rather a still more burning glow. The pools which the yellow fading branches of the fan-palm had protected from eva- poration now gradually disappear. As in the icy North the animals become tor- pid with cold, so here, under the influence of the parching drought, the crocodile and the boa become motionless and fall asleep, deeply buried in the dry mad. Everywhere the death-threatening drought prevails; and yet by the play of tbe re- fracted rays of light producing the pbmnomenon of the mirage, the thirsty is everywhere pursued by the illusive image of a cool rippling watery mirror. The distant palm-bush, apparently raised by the influence of the contact of un- equally heated ahd therefore unequally dense strata of air, hovers above the ground, from which it is separated by a narrow intervening margin. Half c". coded by the dark clouds of dust, restless with the pain of thirst and hunger, tee traveller horses and cattle roam around, the cattle lowing dismally, and the horses stretch- ing out their long necks and snuffirig the wind, if haply a moister current BAY, betray the neighbourhood of a not wholly dried-up pool. More sagacious. opt conning, the _mule seeks a different mode of alleviating his thirst. The DIM, • Allman of Nature in Dirierent Lauds and Different Climates; with Scientific Mick dation& By Alexand9a°5-41901014. vraushysd by Mp. fiktbIne. Inivr0volulna Published by Longmein and Co:, and ig -

and spherical melon-cactus coneetes under it& prickly envelop a watery pith: the mule first strikes the prickles rig& with his fore feet, and then ventures warily to approach his lips to the plant and drink the cool juice. But resort to this vege- table fountain is not always without danger; and one sees many animals that have been lamed by the prickles of the cactus."

Take the contrast offered by the rains.

" At length, after the long drought, the welcome season of the rain arrives; and then how suddenly is the scene changed. The deep blue of the hitherto per- petually cloudless sky becomes lighter ; at night the dark space in the constella- tion of the Southern Cross is hardly distinguishable; the soft phosphorescent light of the Magellanic clouds fades away; even the stars in Aquila and Ophiucus in the zenith shine with a trembling and less planetary light. A single cloud appears in the South, like a distant mountain, rising perpendicularly from the horizon: gradually the increasing vapours spread like mist over the sky, and now the distant thunder ushers in the life-restoring rain. Hardly has the surface of the earth received the refreshing moisture before the previously barren steppe be- gins to exhale sweet odours, and to clothe itself with kyllingias, the many pani- tides of the paspaltim, and a variety of grasses. The herbaceous mimosas, with renewed sensibility to the influence of light, unfold their drooping slumbering leaves to greet the rising sun; and the early song of birds, and the opening blossoms of the water-plants, join to salute the morning. The horses and cattle now graze in full enjoyment of life. The tall springing grass hides the teauti- fatly spotted jaguar, who, lurking in safe concealment, and measuring carefully thaistance of a single bound, springs, cat-like, as the Asiatic tiger, on his pass- ing prey.

"Sometimes, (so the Aborigines relate,) on the margin of the swamps the moistened clay is seen to blister and rise slowly in a kind of mound ; then, with a violent noise, like the outbreak of a small mud volcano, the heaped-up earth is east high into the air. The beholder acquainted with the meaning of this spec- tacle flies, for he knows there will issue forth a gigantic water-snake or a scaly crocodile, awakened from a torpid state by the first fall of rain. "The rivers which bound the plain to the South, the Arauca, Apure, and Payers, become gradually swollen ; and now nature constrains the same animals who in the first half of the year panted with thirst on the dry and dusty soil to adopt an amphibious life. A portion of the Steppe now presents the aspect of a vast inland sea. The brood-mares retire with their foals to the higher banks, which stand like islands above the surface of the lake. Every day the space re- maining dry becomes smaller. The animals, crowded together, swim about for hours in search of other pasture, and feed sparingly on the tops of the flowering grasses rising above the seething surface of the dark-coloured water. Many foals are drowned, and many are surprised by the crocodiles, killed by a stroke of their powerful notched tails, and devoured. It is not a rare thing to see the marks of the pointed teeth of these monsters on the legs of the horses and cattle who have

narrowly escaped from their blood-thirsty jaws. * *

"But the crocodile and jaguar aro not the only assailants of the South Ame- rican horses; they have also a dangerous enemy among fishes. The marshy waters of Bern and Ream are filled with numberless electric eels, which can at pleasure send a powerful discharge from any part of their slimy yellow spotted bodies. These gymnoti are from five to six feet in length, and are powerful enough to kill the largest animals when they discharge their nervous organs at once in a favourable direction.

"The route from Datunu through the Steppe was formerly obliged to be changed, because the gymnoti had increased to such numbers in a small stream, that in crossing it many horses were drowned every year, either from the effects of the shocks they received, or from fright."

Extracts of this kind might readily be multiplied from the textual de- scriptions; but we will now take, as a sample of the notes a quotation having a practical bearing on a subject which events have rendered of great importance—a communication between the Atlantic and Pacific Oceans by the Isthmus. The text that furnishes the note is a passing allusion to the expedition of Vasco Nunez de Balboa.

"Having for more than forty years been occupied with the subject of the means of communication between the two seas, I have constantly, both in my printed works and in the different memoirs which with honourable confidence the Free States of Spanish America have requested me to furnish, urged that the Isthmus should be examined hypsometrically throughout its entire length, and more es- pecially where, in Darien and the inhospitable former Provincia de Biruquete, it joins the continent of South America; and where, between the Atrato and the Bay of Cupica, (on the shore of the Pacific,) the mountain-chain of the Isthmus

almost entirely disappears. *

" General Bolivar at my request caused an exact levelling of the Isthmus be- tween Panama and the mouth of the Rio Chagres to be made in 1828 and 1829 by Lloyd and Falmarc. (Philosophical Transactions of the Royal Society of Lon- don for the year 1830, p. 59-68.) Other measurements have since been executed by accomplished and experienced French engineers, and projects have been formed for canals and railways with locks and tunnels, bat always in the direction of a meridian between Portobello and Panama,—or more to the West, towards Chagres and Cruces. Thus the most important points of the Eastern and South-eastern part of the Isthmus have remained unexamined on both shores! So long as this part is not examined geographically by means of exact but easily obtained de- terminations of latitude and of longitude by chronometers, as well as hypso- metrically in the conformation of the surface by barometric measurements of elevation, so long I consider that the statement I have repeatedly made and which I now repeat in 1849, will still be true—viz. 'that it is as yet unproved and quite premature to pronounce that the Isthmus does not admit of the formation of an oceanic canal, (i e. a canal with fewer locks than the Caledonian Canal,) permitting at all seasons the passage of the same sea-going ships between New -York and Liverpool on the one hand, and Chili and California on the other.' "On the Atlantic side, (according to examinations which the Direccion of the Deposits Hidrografico of Madrid have entered on their maps since 1809,) the Eu- senada de Mandinga penetrates so deeply towards the South that it appears to be only four or five German geographical miles, fifteen to an Equatorial degree, (i e. sixteen or twenty Euglish geographical miles,) from the coast of the Pacific on the East of Panama. On the Pacific side the Isthmus is almost equally indented by the deep Golfo de San Miguel, into which the Rio Tuyra falls, with its tribu- tary river the Chuchunque (Chuchunaque). This last-named stream in the upper part of its course approaches within sixteen English geographical miles of the Atlantic side of the Isthmus to the West of Cape Tiburon. For more than twenty years I have had inquiries made from me on the subject of the problem of the Isthmus of Panama, by associations desirous of employing considerable pecuniary meansi but the simple advice which I have given has never been fol- lowed. Every scientifically-educated engineer knows that between the Tropics, (even without corresponding observations, good barometric measurements (the heresy variations being taken into account afford results which are well assured to be less than from seventy to ninety French or seventy-live to ninety-six English feet. It would besides be easy to establish for a few months on the two shores two fixed corresponding barometric stations, and to compare repeatedly the portable in- struments employed in prelimin.ary levelling, with each other and "nth thoseat the fixed stations. Let that part be particularly examined where, near the con- tinent of South America, the separating mountain ridge sinks into hills. Seeing, the imPortinee of the subject to the great commerce of the world, the res-urch ought dot, as hithtito, to be restricted to a limited field.*

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