above the north-west margin. This singular cone, which from Naples appeared to be the true summit of the mountain, fell in with a dreadful noise on the eruption of the 22d October, 1822, "so that the floor of the crater, which had been constantly accessible since 1811, is now almost 800 feet lower than the northern, and 218 lower than the southern edge of the volcano."

"In the last eruption, on the night of the 23d to the 24th October, 1822, twenty-four hours after the falling in of the great cone of scoriæ, which has been mentioned, and when the small but nu

merous currents of lava had already flowed off, the fiery eruption of ashes and rapilli commenced; it continued without intermission for twelve days, but was greatest in the first four days. During this period the detonations in the interior of the volcano were so violent, that the

loose and movable as shifting sand, issued in large quantities from a crevice in the upper margin of the crater."-Pp. 229, 230.

Owing to the thunderstorm noticed in this extract, an abundant, and violent fall of rain took place, and as the rain is heaviest above the cone of ashes, torrents of mud descend from it in every direction; and when the summit of the volcano is in the region of perpetual snow, the melting of the snow produces very disastrous inundations. At the foot of volcanoes, too, and on their flanks, there are frequently vast cavities, which, having a communication by many channels with mountain torrents, become subterranean lakes or reservoirs of water. When earthquakes, as happens in the Andes, shake the entire mass of the volcano, these reservoirs are opened, discharging water, fishes, and mud. On the 19th

high, fell in, an area of nearly thirty June, 1698, when the Carguairazo, to the north of Chimborazo, and upward of 19,000 square miles was covered with mud and fishes!

mere concussion of the air (for no earthquake
movement was perceived) rent the ceilings of
the rooms in the palace of Portici. In the neigh-feet
boring villages of Resina, Torre del Greco, Tor
re del Annunziata, and Bosche tre Case, a remark-
able phenomenon was witnessed. Throughout
the whole of that part of the country the air
was so filled with ashes as to cause in the mid-
dle of the day profound darkness, lasting for sev-
eral hours: lanterns were carried in the streets,
as had often been done in Quito during the
eruptions of Pinchincha. The flight of the in-
habitants had never been more general. Lava
currents are regarded by those who dwell near
Vesuvius with less dread than an eruption of
ashes, a phenomenon which had never been known
to such a degree in modern times; and the ob-

scure tradition of the manner in which the de

struction of Herculaneum, Pompeii, and Stabiæ, took place, filled the imaginations of men with appalling images.* The hot aqueous vapors which rose from the crater during the eruption, and spread themselves in the atmosphere, formed, in cooling, a dense cloud, surrounding the column of fire and ashes which rose to a height of Flashes of forked lightning issuing from the col umns of ashes darted in every direction, and the rolling thunders were distinctly heard, and distinguished from the sounds which proceeded from the interior of the volcano. In no other eruption had the play of the electric forces formed so striking a feature.

between nine and ten thousand feet.

"On the morning of the 26th October, a surprising rumor prevailed that a torrent of boiling water was gushing from the crater, and pouring down the slope of the cone of ashes. Monticelli soon discovered that this was an optical illusion. It was in reality a flow of dry ashes, which, being

*The thickness of the bed of ashes which fell during the twelve days was little above three feet on the slope of the cones, and only about eighteen inches on the planes. This is the greatest fall of ashes since the eruption of Vesuvius, which occasioned the death of the elder Pliny.

Vesuvius, and other similar volcanoes, of their craters with the interior of the earth. have permanent communications by means They alternately break forth and slumber, and often "end by becoming solfataras, emitting aqueous vapors, gases, and acids." There is, however, another and a rarer class, which are closely connected with the earliest revolutions of our planet. Trachytic mountains open suddenly, emit lava and ashes, and The gigantic close again perhaps for ever. mountain of Antisana on the Andes, and Monte Epomeo in Ischia, in 1302, are examples of that phenomenon. Eruptions of this kind sometimes takes place in the plains, as happened in Quito, in Iceland, at a distance from Hecla, and in Euboea in the Lelantine fields. Many of the islands upheaved from the sea belong to the same class. The communication of the external opening with the interior of the earth is not permanent, and as soon as the cleft or opening closes, the volcanic action wholly ceases. Humboldt is of opinion that "veins or dykes of basalt, dolerite, and porphyry, which traverse almost all formations, and that masses of syenite, augitic porphyry, and amygdaloid, which characterize the recent transition and oldest sedimentary rocks, have probably been formed in a similar manner.'

That the earth is a melted mass at no very great depth below its surface, is placed beyond a doubt, not only by the preceding facts, but by a great mass of observations

collected by Humboldt and Arago, on the increase of temperature as we descend into the bowels of the earth. "The primitive cause of this subterranean heat is, as in all planets, the process of formation itself, the separation of the spherically condensing mass from a cosmical gaseous fluid, and the cooling of the terrestrial strata at different depths by the loss of heat parted with by Elastic vapors press the molten oxydizing substances upward through deep fissures. Volcanoes might thus be termed intermitting springs or fountains of earthy substances; that is, of the fluid mixture of metals, alkalis, and earths, which solidify into lava currents, and flow softly and tranquilly, when being upheaved they find a passage by which to escape."

radiation.

Our author concludes this instructive section with a speculation which he himself characterizes as bold; the object of which is to explain, by means of the internal heat of our globe, the existence, in a fossil state, of the tropical forms of animals and plants in the cold regions of the globe. This hitherto unexplained fact has been ascribed to various causes, to a change in the obliquity of the ecliptic by the approach of a comet, and to a change in the intensity of the sun's light and heat. We have been led to suppose that, as the two poles of maximum cold are nearly coincident with the magnetic poles, they may partake in their revolution, and thus make the warm and the cold meridians which are now proved to exist, occupy in succession every position on the earth's surface; and that variations in the forces or causes by which that cold is produced, may produce a still farther variation of temperature.*

ern regions, it should be assumed that the longhaired species of elephant now found enclosed in ice, was originally indigenous in cold climates, and that forms resembling the same leading type may, as in the case of lions and lynxes, have been able to live in wholly different climates; still this solution of the difficulty presented by fossil remains cannot be extended so as to apply to vegetable productions. From reasons with which the study of physiology makes us acquainted, palms, musacea, and arborescent monocotyledones, are incapable of supporting the deprivation of their appendicular organs, which would be caused by the present temperature of our northern regions; and in the geological problem which we have to examine, it appears to me difficult to separate vegetable and animal remains from each other. The same mode of explanatiou ought to comprehend both."-Vol. ii. pp. 239, 241.

The next chapter of the "Aspects of Nature" is one of seven pages, entitled, "The Vital Force, or the Rhodian Genius." It was first printed in Schiller's Hora for 1795, and contains "the development of a physiological idea in a semi-mythical garb." In an earlier work, our author had defined the vital force as "the unknown cause which prevents the elements from following their original affinities;" and he endeavors to illustrate this position by the following story:-A picture, called the Rhodian Genius, was brought to Syracuse from Greece, and was supposed to be the work of the same artist who cast the Colossus of Rhodes. It was placed in the Gallery of Paintings and Sculpture, and excited much difference of opinion, both respecting its author and its object. On the foreground were youths and maidens, handsome and graceful, but unclothed, and expressing in their features and movements, only the desires and sorrows of an earthly habitation. Their arms outstretched to each other, indicated "their desire of union;" but they turned their troubled looks toward a halo-encircled Genius who stood in the midst of them. On his shoulder was a butterfly, and in his hand a lighted torch. Though childlike in his form and aspect, a celestial fire animated his glance, and he gazed as with the eye of a master upon the gay throng at his feet. The object of the picture became volcanoes would be that of the interior of the a problem, which philosophers and connoisEarth; and the same cause, which, operating through volcanic eruptions, now produces devasseurs strove to solve. "Some regarded the tating effects, might, in primeval ages, have Genius as the personification of Spiritual clothed the deeply-fissured rocks of the newly Love forbidding the enjoyment of sensual oxydized Earth, in every zone, with the most luxu-pleasure: others said, that it was the asserriant vegetation.

66

Everywhere," says our author, "the ancient world shows a distribution of organic forms at variance with our present elimate. It

may be that, in the ancient world, exhala ions of heat issuing forth from the many openings of the deeply-fissured crust of the globe, may have favored, perhaps, for centuries, the growth of palins and tree-ferns, and the existence of animals requiring a high temperature, over entire countries where now a very different climate prevails. According to this view of things, the temperature of

"If, in order to explain the distribution of tropical forms, whose remains are now buried in north

* Edinburgh Transactions, vol. ix. pp. 211, 212.

tion of the Empire of Reason over Desire.". A collection of pictures having arrived from Rhodes, there was found among them the companion or pendant of the Rhodian Genius.

The Genius was still the central figure; but his head was now drooping. The butterfly was no longer on his shoulder; and his torch was inverted and extinguished. "The youths and maidens pressing around him had met and embraced. Their glance, no longer sad and subdued, announced, on the contrary, emancipation from restraint, and the fulfillment of long-cherished desires."

The companion picture afforded no clue to the solution of the problem; and in this crisis of baffled ingenuity and disappointed curiosity, Dionysius ordered the picture, along with a faithful copy of the Rhodian Genius, to be carried to the house of Epicharmus, a Pythagorean philosopher, who fixed his eyes upon the picture, and thus addressed his disciples:

them, without regard to their ancient rights, to obey his laws.

Now view with me the new picture which the Tyrant has sent to me for explanation; turn your eyes from the image of life to that of death. The butterfly has left its former place and soars upward, the extinguished torch is reversed, the head of the youth has sunk, the spirit has fled to other spheres, and the vital force is dead. Now the youths and maidens joyfully join hands, the earthy substances resume their ancient rights; they are free from the chains that bound them, and follow impetuously after long restraint, the impulse to union. Thus inert matter, animated awhile by vital force, passes through an innumerable diversity of forms, and perhaps in the same substance which once enshrined the spirit of Pythagoras, a poor worm may have enjoyed a mopp. 255-257. mentary existence.”__Vol. ii.

The closing chapter of Baron Humboldt's work contains an account of the Plateau "As living beings are compelled by natural de- of Caxamarca, the ancient capital of the sires to salutary and fruitful union, so the raw materials of inorganic matter are moved by simi- Inca Atahualpa, and describes the first lar impulses. Thus the fire of Heaven view of the Pacific Ocean as seen from follows metal,-iron obeys the attraction of the the crest of the Andes. After mentioning loadstone, amber rubbed takes up light sub- the Quina (or fever-bark)* producing forests stances, earth mixes with earth, salt collects in the valleys of Loxa, and the alpine vegetogether from the water of the sea,-and the acid tation and mountain wildernesses of the Pamoisture of the Stypteria, as well as the flocculent salt of Trichitis, love the clay of Melos. In ramos, our author describes the gigantic reinanimate nature, all things hasten to unite with mains of the ancient artificial roads of the each other, according to their particular laws. Incas of Peru, which formed a line of comHence no terrestrial element is to be found any- munication through all the provinces of the where in its pure and primitive state. Each as empire, extending more than a thousand Ensoon as formed tends to enter into new combina-glish miles. The road itself is 21 feet wide, tions, and the art of man is needed to disjoin and present in a separated state substances which you would seek in vain in the interior of the Earth, and in the fluid ocean of air and water. In dead inorganic matter, entire inactivity and repose reign, so long as the bands of affinity continue undissolved, so long as no third substance comes to join itself to the others; but even then the action and disturbance produced are soon again succeeded by unfruitful repose.

"It is otherwise, however, when the same substances are brought together in the bodies of plants and animals. In these the vital force of power reigns supreme, and regardless of the mutual amity or enmity of the atoms recognized by Democritus, commands the union of substances which, in inanimate nature, shun each other, and separates those which are ever seeking to enter into combination.

"Now come nearer to me, my friends; look with me on the first of the pictures before us, and recognize in the Rhodian Genius, in the expression of youthful energy, in the butterfly on his shoulder, and in the commanding glance of his eye, the symbol of vital force animating each individual germ of the organic creation. At the feet are the earthy elements desiring to mix and unite conformably to their particular tendencies. The Genius, holding aloft his lighted torch with commanding gesture, controls and constrains

and above a deep understructure was paved with well cut blocks of blackish trap porphyry. Station-houses, of hewn stone, are built at nearly equal distances, forming a kind of caravanserai. In the pass called the Paramo del Assuay, the road rises to the height of 15,526 feet, almost equal to that of Mon Blanc. Across the wide and arid plains between the Pacific and the Andes, and also over the ridges of the Cordilleras, these two great Peruvian roads, or systems of roads, are covered with flat stones, or "sometimes even with cemented gravel, (Macadamized.)" The roads crossed the rivers and ravines by three kinds of bridges, "viz., those of stone, wood, and rope, and there were also aqueducts for bringing water to the caravanserais and to the fortresses." As wheel-carriages were not then used upon roads, they were occasionally interrupted by long flights of steps, provided with resting-places at suitable

*The Cinchona Condaminia (officinalis). This beautiful tree, though only six inches in diameter, often attains a height of sixty feet. The bark was introduced into Europe in 1682 or 1640.

tops or crowns, they have aspiring branches like a laurel or bay tree."

near

"Not far from hence," says Humboldt, the Ford of Cavico, we were surprised by a very unexpected sight. We saw We saw a grove of small trees, only about 18 or 19 feet high, which, inrose-colored leaves. It was a new species of stead of green, had apparently perfectly red or Bougainvillæa, a genus first establ shed by the elder Jussieu from a Brazilian specimen in Commerson's herbarium. The trees were almost entirely without true leaves, as what we took for bracteas. The appearance was altogether different in the purity and freshness of the color from the autumnal tints which, in many of our forest trees, adorn the woods of the temperate zone at the season of the fall of the leaf. We often found here the Porlieria hygrometrica, which, by the closing of the leaflets of its finely pinnated foliage, foretells an impending change of much better than any of the Mimosacea. It weather, and especially the approach of rain, very rarely deceived us."--Vol. ii. pp. 279, 280.

intervals. Along with their grand artificial | paths, the Peruvians possessed a highly improved postal system. These splendid remains of the Incas, however, have been wantonly destroyed, and Humboldt mentions that in one day's journey they were obliged to wade through the Rio de Guancabamba twenty-seven times, while they continually saw near them the remains of the high built roads, with their caravanserais. In the lower part of the same river, which, with its many falls and rapids, runs into the Amazons, our author was amused with the singular contriv-leaves at a distance proved to be thickly crowded ance of a "Swimming Post," for the conveyance of correspondence with the coast of the Pacific. Α young Indian, who usually discharges this important duty, swims in two days from Pomahuaco to Tomependa, carrying the few letters from Truxillo, which are intended for the province of Jaen de Bracamora. The letters are carefully placed in a large cotton handkerchief, which he winds round his head in the manner of a turban. He then descends the Rio de Chamaya (the lower part of the Guancabamba), and then the Amazons. When he reaches waterfalls, he quits the river and makes a circuit through the woods. In this fatiguing voyage, the Indian sometimes throws one arm round a piece of a very light kind of wood, and he has sometimes the advantage of a swimming companion. They carry no provision, as they are always sure of a hospitable reception in any of the scattered huts surrounded with fruit trees, which abound in the beautiful Huertas de Pucara and Cavico. Letters thus carried are seldom either wetted or lost; and Humboldt mentions, that soon after his return from Mexico to Europe, he received letters from Tomependa, which had been bound on the brow of the swimming post. The "Correo que nada,' as he is called, returns by land by the difficult route of the Paramo del Paredon. Several tribes of wild Indians, who reside on the banks of the Upper Amazons, are accustomed to travel "by swimming down the stream sociably in parties." Humboldt had an "opportunity of seeing in this manner in the bed of the river the heads of 30 or 40 persons (men, women, and children), of the tribe of the Xibaros, on their arrival at Tomependa."

When the travelers approached the hot climate of the basin of the Amazons, they were delighted with the splendid orange trees, sweet and bitter, of the Huertas de Pucara. "Laden with many thousands of their golden fruit, they attain a height of from 60 to 64 feet, and instead of rounded

when they were ascending the eastern declivAs night was closing upon our travelers, ity of the Cordilleras, they arrived at an elevated plain where the argentiferous mountains of Gualgayoc, the chief locality of the celebrated Silver Mines of Chota, afforded them a remarkable spectacle. The cerro of Gualgayoc, an isolated mass of silicious rock, stands like an enchanted castle, separated by a deep ravine from the limestone mountains of Cormolatsche. It is traversed by innumerable veins of silver, and terminated on the N. W. by a nearly perpendicular precipice. "Besides being perforated to its summit by many hundred galleries driven in every direction, this mountain presents also natural openings in the mass of the silicious rock, through which the intensely dark blue sky of those elevated regions is visible to a spectator standing at the foot of the mountain. These openings are popularly called windows," and "similar ones were pointed out to us in the trachytic walls of the volcano of Pinchincha."

On their way to the ancient city of Caxamarca, Humboldt and his companions had to cross a succession of Paramos at the height of about 10,000 feet above the sea, before they reached the Paramo de Yanaguanga, from which they looked down upon the fertile valley of Caxamarca, containing in its oval area about 112 English square miles. The town stands almost as high as the city of Quito, but being encircled by mountains, it enjoys a far milder climate. The fort and palace of Atahualpa exist only in a few ru