In order to escape as much as possible from the heat of the day, we

set off at two in the morning, with the hope of reaching Calabozo

before noon, a small but busy trading-town, situated in the midst of

the Llanos. The aspect of the country was still the same. There was no

moonlight; but the great masses of nebulae that spot the southern sky

enlighten, as they set, a part of the terrestrial horizon. The solemn

spectacle of the starry vault, seen in its immense expanse--the cool

breeze which blows over the plain during the night--the waving motion

of the grass, wherever it has attained any height; everything recalled

to our minds the surface of the ocean. The illusion was augmented when

the disk of the sun appearing on the horizon, repeated its image by

the effects of refraction, and, soon losing its flattened form,

ascended rapidly and straight towards the zenith.

Sunrise in the plains is the coolest moment of the day; but this

change of temperature does not make a very lively impression on the

organs. We did not find the thermometer in general sink below 27.5;

while near Acapulco, at Mexico, and in places equally low, the

temperature at noon is often 32, and at sunrise only 17 or 18 degrees.

The level surface of the ground in the Llanos, which, during the day,

is never in the shade, absorbs so much heat that, notwithstanding the

nocturnal radiation toward a sky without clouds, the earth and air

have not time to cool very sensibly from midnight to sunrise.

In proportion as the sun rose towards the zenith, and the earth and

the strata of superincumbent air took different temperatures, the

phenomenon of the mirage displayed itself in its numerous

modifications. This phenomenon is so common in every zone, that I

mention it only because we stopped to measure with some precision the

breadth of the aerial distance between the horizon and the suspended

object. There was a constant suspension, without inversion. The little

currents of air that swept the surface of the soil had so variable a

temperature that, in a drove of wild oxen, one part appeared with the

legs raised above the surface of the ground, while the other rested on

it. The aerial distance was, according to the distance of the animal,

from 3 to 4 minutes. Where tufts of the moriche palm were found

growing in long ranges, the extremities of these green rows were

suspended like the capes which were, for so long a time, the subject

of my observations at Cumana. A well-informed person assured us, that

he had seen, between Calabozo and Uritucu, the image of an animal

inverted, without there being any direct image. Niebuhr made a similar

observation in Arabia. We several times thought we saw on the horizon

the figures of tumuli and towers, which disappeared at intervals,

without our being able to discern the real shape of the objects. They

were perhaps hillocks, or small eminences, situated beyond the

ordinary visual horizon. I need not mention those tracts destitute of

vegetation, which appear like large lakes with an undulating surface.

This phenomenon, observed in very remote times, has occasioned the

mirage to receive in Sanscrit the expressive name of desire of the

antelope. We admire the frequent allusions in the Indian, Persian, and

Arabic poets, to the magical effects of terrestrial refraction. It was

scarcely known to the Greeks and Romans. Proud of the riches of their

soil, and the mild temperature of the air, they would have felt no

envy of this poetry of the desert. It had its birth in Asia; and the

oriental poets found its source in the nature of the country they

inhabited. They were inspired with the aspect of those vast solitudes,

interposed like arms of the sea or gulfs, between lands which nature

had adorned with her most luxuriant fertility.

The plain assumes at sunrise a more animated aspect. The cattle, which

had reposed during the night along the pools, or beneath clumps of

mauritias and rhopalas, were now collected in herds; and these

solitudes became peopled with horses, mules, and oxen, that live here

free, rather than wild, without settled habitations, and disdaining

the care and protection of man. In these hot climates, the oxen,

though of Spanish breed, like those of the cold table-lands of Quito,

are of a gentle disposition. A traveller runs no risk of being

attacked or pursued, as we often were in our excursions on the back of

the Cordilleras, where the climate is rude, the aspect of the country

more wild, and food less abundant. As we approached Calabozo, we saw

herds of roebucks browsing peacefully in the midst of horses and oxen.

They are called matacani; their flesh is good; they are a little

larger than our roes, and resemble deer with a very sleek skin, of a

fawn-colour, spotted with white. Their horns appear to me to have

single points. They had little fear of the presence of man: and in

herds of thirty or forty we observed several that were entirely white.

This variety, common enough among the large stags of the cold climates

of the Andes, surprised us in these low and burning plains. I have

since learned, that even the jaguar, in the hot regions of Paraguay,

sometimes affords albino varieties, the skin of which is of such

uniform whiteness that the spots or rings can be distinguished only in

the sunshine. The number of matacani, or little deer,* (* They are

called in the country Venados de tierras calientes (deer of the warm

lands.)) is so considerable in the Llanos, that a trade might be

carried on with their skins.* (* This trade is carried on, but on a

very limited scale, at Carora and at Barquesimeto.) A skilful hunter

could easily kill more than twenty in a day; but such is the indolence

of the inhabitants, that often they will not give themselves the

trouble of taking the skin. The same indifference is evinced in the

chase of the jaguar, a skin of which fetches only one piastre in the

steppes of Varinas, while at Cadiz it costs four or five.

The steppes that we traversed are principally covered with grasses of

the genera Killingia, Cenchrus, and Paspalum.* (* Killingia

monocephala, K. odorata, Cenchrus pilosus, Vilfa tenacissima,

Andropogon plumosum, Panicum micranthum, Poa repens, Paspalum

leptostachyum, P. conjugatum, Aristida recurvata. (Nova Genera et

Species Plantarum, volume 1 pages 84 to 243.) At this season, near

Calabozo and San Jerome del Pirital, these grasses scarcely attain the

height of nine or ten inches. Near the banks of the Apure and the

Portuguesa they rise to four feet in height, so that the jaguar can

conceal himself among them, to spring upon the mules and horses that

cross the plain. Mingled with these gramina some plants of the

dicotyledonous class are found; as turneras, malvaceae, and, what is

very remarkable, little mimosas with irritable leaves,* called by the

Spaniards dormideras. (* The sensitive-plant Mimosa dormiens.) The

same breed of cows, which fatten in Europe on sainfoin and clover,

find excellent nourishment in the herbaceous sensitive plants. The

pastures where these shrubs particularly abound are sold at a higher

price than others. To the east, in the llanos of Cari and Barcelona,

the cypura and the craniolaria,* (* Cypura graminea, Craniolaria

annua, the scorzonera of the natives.) the beautiful white flower of

which is from six to eight inches long, rise solitarily amid the

gramina. The pastures are richest not only around the rivers subject

to inundations, but also wherever the trunks of palm-trees are near

each other. The least fertile spots are those destitute of trees; and

attempts to cultivate them would be nearly fruitless. We cannot

attribute this difference to the shelter afforded by the palm-trees,

in preventing the solar rays from drying and burning up the soil. I

have seen, it is true, trees of this family, in the forests of the

Orinoco, spreading a tufted foliage; but we cannot say much for the

shade of the palm-tree of the llanos, the palma de cobija,* (* The

roofing palm-tree Corypha tectorum.) which has but a few folded and

palmate leaves, like those of the chamaerops, and of which the

lower-most are constantly withered. We were surprised to see that

almost all these trunks of the corypha were nearly of the same size,

namely, from twenty to twenty-four feet high, and from eight to ten

inches diameter at the foot. Nature has produced few species of

palm-trees in such prodigious numbers. Amidst thousands of trunks

loaded with olive-shaped fruits we found about one hundred without

fruit. May we suppose that there are some trees with flowers purely

monoecious, mingled with others furnished with hermaphrodite flowers?

The Llaneros, or inhabitants of the plains, believe that all these

trees, though so low, are many centuries old. Their growth is almost

imperceptible, being scarcely to be noticed in the lapse of twenty or

thirty years. The wood of the palma de cobija is excellent for

building. It is so hard, that it is difficult to drive a nail into it.

The leaves, folded like a fan, are employed to cover the roofs of the

huts scattered through the Llanos; and these roofs last more than

twenty years. The leaves are fixed by bending the extremity of the

footstalks, which have been beaten beforehand between two stones, so

that they may bend without breaking.

Beside the solitary trunks of this palm-tree, we find dispersed here

and there in the steppes a few clumps, real groves (palmares), in

which the corypha is intermingled with a tree of the proteaceous

family, called chaparro by the natives. It is a new species of

rhopala,* (* Resembling the Embothrium, of which we found no species

in South America. The embothriums are represented in American

vegetation by the genera Lomatia and Oreocallis.) with hard and

resonant leaves. The little groves of rhopala are called chaparales;

and it may be supposed that, in a vast plain, where only two or three

species of trees are to be found, the chaparro, which affords shade,

is considered a highly valuable plant. The corypha spreads through the

Llanos of Caracas from Mesa de Peja as far as Guayaval; farther north

and north-west, near Guanare and San Carlos, its place is taken by

another species of the same genus, with leaves alike palmate but

larger. It is called the royal palm of the plains (palma real de los

Llanos).* (* This palm-tree of the plains must not be confounded with

the palma real of Caracas and of Curiepe, with pinnate leaves.) Other

palm-trees rise south of Guayaval, especially the piritu with pinnate

leaves,* (* Perhaps an Aiphanes.) and the moriche (Mauritia flexuosa),

celebrated by Father Gumilla under the name of arbol de la vida, or

tree of life. It is the sago-tree of America, furnishing flour, wine,

thread for weaving hammocks, baskets, nets, and clothing. Its fruit,

of the form of the cones of the pine, and covered with scales,

perfectly resembles that of the Calamus rotang. It has somewhat the

taste of the apple. When arrived at its maturity it is yellow within

and red without. The araguato monkeys eat it with avidity; and the

nation of the Guaraounos, whose whole existence, it may be said, is

closely linked with that of the moriche palm-tree, produce from it a

fermented liquor, slightly acid, and extremely refreshing. This

palm-tree, with its large shining leaves, folded like a fan, preserves

a beautiful verdure at the period of the greatest drought. The mere

sight of it produces an agreeable sensation of coolness, and when

loaded with scaly fruit, it contrasts singularly with the mournful

aspect of the palma de cobija, the foliage of which is always grey and

covered with dust. The Llaneros believe that the former attracts the

vapours in the air;* (* If the head of the moriche were better

furnished with leaves than it generally is, we might perhaps admit

that the soil round the tree preserves its humidity through the

influence of the shade.) and that for this reason, water is constantly

found at its foot, when dug for to a certain depth. The effect is

confounded with the cause. The moriche grows best in moist places; and

it may rather be said that the water attracts the tree. The natives of

the Orinoco, by analogous reasoning, admit, that the great serpents

contribute to preserve humidity in a province. "You would look in vain

for water-serpents," said an old Indian of Javita to us gravely,

"where there are no marshes; because the water ceases to collect when

you imprudently kill the serpents that attract it."

We suffered greatly from the heat in crossing the Mesa de Calabozo.

The temperature of the air augmented sensibly every time that the wind

began to blow. The air was loaded with dust; and during these gusts

the thermometer rose to 40 or 41 degrees. We went slowly forward, for

it would have been dangerous to leave the mules that carried our

instruments. Our guides advised us to fill our hats with the leaves of

the rhopala, to diminish the action of the solar rays on the hair and

the crown of the head. We found relief from this expedient, which was

particularly agreeable, when we could procure the thick leaves of the

pothos or some other similar plant.

It is impossible to cross these burning plains, without inquiring

whether they have always been in the same state; or whether they have

been stripped of their vegetation by some revolution of nature. The

stratum of mould now found on them is in fact very thin. The natives

believe that the palmares and the chaparales (the little groves of

palm-trees and rhopala) were more frequent and more extensive before

the arrival of the Spaniards. Since the Llanos have been inhabited and

peopled with cattle become wild, the savannah is often set on fire, in

order to ameliorate the pasturage. Groups of scattered trees are

accidentally destroyed with the grasses. The plains were no doubt less

bare in the fifteenth century, than they now are; yet the first

Conquistadores, who came from Coro, described them then as savannahs,

where nothing could be perceived but the sky and the turf, generally

destitute of trees, and difficult to traverse on account of the

reverberation of heat from the soil. Why does not the great forest of

the Orinoco extend to the north, on the left bank of that river? Why

does it not fill that vast space that reaches as far as the Cordillera

of the coast, and which is fertilized by numerous rivers? These

questions are connected with all that relates to the history of our

planet. If, indulging in geological reveries, we suppose that the

steppes of America, and the desert of Sahara, have been stripped of

their vegetation by an irruption of the ocean, or that they formed

originally the bottom of an inland sea, we may conceive that thousands

of years have not sufficed for the trees and shrubs to advance from

the borders of the forests, from the skirts of the plains either naked

or covered with turf, toward the centre, and darken so vast a space

with their shade. It is more difficult to explain the origin of bare

savannahs, encircled by forests, than to recognize the causes that

maintain forests and savannahs within their ancient limits, like

continents and seas.

We found the most cordial hospitality at Calabozo, in the house of the

superintendent of the royal plantations, Don Miguel Cousin. The town,

situated between the banks of the Guarico and the Uritucu, contained

at this period only five thousand inhabitants; but everything denoted

increasing prosperity. The wealth of most of the inhabitants consists

in herds, under the management of farmers, who are called hateros,

from the word hato, which signifies in Spanish a house or farm placed

in the midst of pastures. The scattered population of the Llanos being

accumulated on certain points, principally around towns, Calabozo

reckons already five villages or missions in its environs. It is

computed, that 98,000 head of cattle wander in the pastures nearest to

the town. It is very difficult to form an exact idea of the herds

contained in the Llanos of Caracas, Barcelona, Cumana, and Spanish

Guiana. M. Depons, who lived in the town of Caracas longer than I, and

whose statistical statements are generally accurate, reckons in those

vast plains, from the mouths of the Orinoco to the lake of Maracaybo,

1,200,000 oxen, 180,000 horses, and 90,000 mules. He estimates the

produce of these herds at 5,000,000 francs; adding to the value of the

exportation the price of the hides consumed in the country. There

exist, it is believed, in the Pampas of Buenos Ayres, 12,000,000 cows,

and 3,000,000 horses, without comprising in this enumeration the

cattle that have no acknowledged proprietor.

I shall not hazard any general estimates, which from their nature are

too uncertain; but shall only observe that, in the Llanos of Caracas,

the proprietors of the great hatos are entirely ignorant of the number

of the cattle they possess. They only know that of the young cattle,

which are branded every year with a letter or mark peculiar to each

herd. The richest proprietors mark as many as 14,000 head every year;

and sell to the number of five or six thousand. According to official

documents, the exportation of hides from the whole capitania-general

of Caracas amounted annually to 174,000 skins of oxen, and 11,500 of

goats. When we reflect, that these documents are taken from the books

of the custom-houses, where no mention is made of the fraudulent

dealings in hides, we are tempted to believe that the estimate of

1,200,000 oxen wandering in the Llanos, from the Rio Carony and the

Guarapiche to the lake of Maracaybo, is much underrated. The port of

La Guayra alone exported annually from 1789 to 1792, 70,000 or 80,000

hides, entered in the custom-house books, scarcely one-fifth of which

was sent to Spain. The exportation from Buenos Ayres, at the end of

the eighteenth century, was, according to Don Felix de Azara, 800,000

skins. The hides of Caracas are preferred in the Peninsula to those of

Buenos Ayres; because the latter, on account of a longer passage,

undergo a loss of twelve per cent in the tanning. The southern part of

the savannahs, commonly called the Upper Plains (Llanos de arriba), is

very productive in mules and oxen; but the pasturage being in general

less good, these animals are obliged to be sent to other plains to be

fattened before they are sold. The Llano de Monai, and all the Lower

Plains (Llanos de abaxo), abound less in herds, but the pastures are

so fertile, that they furnish meat of an excellent quality for the

supply of the coast. The mules, which are not fit for labour before

the fifth year, are purchased on the spot at the price of fourteen or

eighteen piastres. The horses of the Llanos, descending from the fine

Spanish breed, are not very large; they are generally of a uniform

colour, brown bay, like most of the wild animals. Suffering

alternately from drought and floods, tormented by the stings of

insects and the bites of the large bats, they lead a sorry life. After

having enjoyed for some months the care of man, their good qualities

are developed. Here there are no sheep: we saw flocks only on the

table-land of Quito.

The hatos of oxen have suffered considerably of late from troops of

marauders, who roam over the steppes killing the animals merely to

take their hides. This robbery has increased since the trade of the

Lower Orinoco has become more flourishing. For half a century, the

banks of that great river, from the mouth of the Apure as far as

Angostura, were known only to the missionary-monks. The exportation of

cattle took place from the ports of the northern coast only, namely

from Cumana, Barcelona, Burburata, and Porto Cabello. This dependence

on the coast is now much diminished. The southern part of the plains

has established an internal communication with the Lower Orinoco; and

this trade is the more brisk, as those who devote themselves to it

easily escape the trammels of the prohibitory laws.

The greatest herds of cattle in the Llanos of Caracas are those of the

hatos of Merecure, La Cruz, Belen, Alta Gracia, and Pavon. The Spanish

cattle came from Coro and Tocuyo into the plains. History has

preserved the name of the colonist who first conceived the idea of

peopling these pasturages, inhabited only by deer, and a large species

of cavy.* (* The thick-nosed tapir, or river cavy (Cavia capybara),

called chiguire in those countries.) Christoval Rodriguez sent the

first horned cattle into the Llanos, about the year 1548. He was an

inhabitant of the town of Tocuyo, and had long resided in New Grenada.

When we hear of the innumerable quantity of oxen, horses, and mules,

that are spread over the plains of America, we seem generally to

forget that in civilized Europe, on lands of much less extent, there

exist, in agricultural countries, quantities no less prodigious.

France, according to M. Peuchet, feeds 6,000,000 large horned cattle,

of which 3,500,000 are oxen employed in drawing the plough. In the

Austrian monarchy, the number of oxen, cows, and calves, has been

estimated at 13,400,000 head. Paris alone consumes annually 155,000

horned cattle. Germany receives 150,000 oxen yearly from Hungary.

Domestic animals, collected in small herds, are considered by

agricultural nations as a secondary object in the riches of the state.

Accordingly they strike the imagination much less than those wandering

droves of oxen and horses which alone fill the uncultivated tracts of

the New World. Civilization and social order favour alike the progress

of population, and the multiplication of animals useful to man.

We found at Calabozo, in the midst of the Llanos, an electrical

machine with large plates, electrophori, batteries, electrometers; an

apparatus nearly as complete as our first scientific men in Europe

possess. All these articles had not been purchased in the United

States; they were the work of a man who had never seen any instrument,

who had no person to consult, and who was acquainted with the

phenomena of electricity only by reading the treatise of De Lafond,

and Franklin's Memoirs. Senor Carlos del Pozo, the name of this

enlightened and ingenious man, had begun to make cylindrical

electrical machines, by employing large glass jars, after having cut

off the necks. It was only within a few years he had been able to

procure, by way of Philadelphia, two plates, to construct a plate

machine, and to obtain more considerable effects. It is easy to judge

what difficulties Senor Pozo had to encounter, since the first works

upon electricity had fallen into his hands, and that he had the

courage to resolve to procure himself, by his own industry, all that

he had seen described in his books. Till now he had enjoyed only the

astonishment and admiration produced by his experiments on persons

destitute of all information, and who had never quitted the solitude

of the Llanos; our abode at Calabozo gave him a satisfaction

altogether new. It may be supposed that he set some value on the

opinions of two travellers who could compare his apparatus with those

constructed in Europe. I had brought with me electrometers mounted

with straw, pith-balls, and gold-leaf; also a small Leyden jar which

could be charged by friction according to the method of Ingenhousz,

and which served for my physiological experiments. Senor del Pozo

could not contain his joy on seeing for the first time instruments

which he had not made, yet which appeared to be copied from his own.

We also showed him the effect of the contact of heterogeneous metals

on the nerves of frogs. The name of Galvani and Volta had not

previously been heard in those vast solitudes.

Next to his electrical apparatus, the work of the industry and

intelligence of an inhabitant of the Llanos, nothing at Calabozo

excited in us so great an interest as the gymnoti, which are animated

electrical apparatuses. I was impatient, from the time of my arrival

at Cumana, to procure electrical eels. We had been promised them

often, but our hopes had always been disappointed. Money loses its

value as you withdraw from the coast; and how is the imperturbable

apathy of the ignorant people to be vanquished, when they are not

excited by the desire of gain?

The Spaniards confound all electric fishes under the name of

tembladores.* (* Literally "tremblers," or "producers of trembling.")

There are some of these in the Caribbean Sea, on the coast of Cumana.

The Guayquerie Indians, who are the most skilful and active fishermen

in those parts, brought us a fish, which, they said, benumbed their

hands. This fish ascends the little river Manzanares. It is a new

species of ray, the lateral spots of which are scarcely visible, and

which much resembles the torpedo. The torpedos, which are furnished

with an electric organ externally visible, on account of the

transparency of the skin, form a genus or subgenus different from the

rays properly so called.* (* Cuvier, Regne Animal volume 2. The

Mediterranean contains, according to M. Risso, four species of

electrical torpedos, all formerly confounded under the name of Raia

torpedo; these are Torpedo narke, T. unimaculata, T. galvanii, and T.

marmorata. The torpedo of the Cape of Good Hope, the subject of the

recent experiments of Mr. Todd, is, no doubt, a nondescript species.)

The torpedo of Cumana was very lively, very energetic in its muscular

movements, and yet the electric shocks it gave us were extremely

feeble. They became stronger on galvanizing the animal by the contact

of zinc and gold. Other tembladores, real gymnoti or electric eels,

inhabit the Rio Colorado, the Guarapiche, and several little streams

which traverse the Missions of the Chayma Indians. They abound also in

the large rivers of America, the Orinoco, the Amazon, and the Meta;

but the force of the currents and the depth of the water, prevent them

from being caught by the Indians. They see these fish less frequently

than they feel shocks from them when swimming or bathing in the river.

In the Llanos, particularly in the environs of Calabozo, between the

farms of Morichal and the Upper and Lower Missions, the basins of

stagnant water and the confluents of the Orinoco (the Rio Guarico and

the canos Rastro, Berito, and Paloma) are filled with electric eels.

We at first wished to make our experiments in the house we inhabited

at Calabozo; but the dread of the shocks caused by the gymnoti is so

great, and so exaggerated among the common people, that during three

days we could not obtain one, though they are easily caught, and we

had promised the Indians two piastres for every strong and vigorous

fish. This fear of the Indians is the more extraordinary, as they do

not attempt to adopt precautions in which they profess to have great

confidence. When interrogated on the effect of the tembladores, they

never fail to tell the Whites, that they may be touched with impunity

while you are chewing tobacco. This supposed influence of tobacco on

animal electricity is as general on the continent of South America, as

the belief among mariners of the effect of garlic and tallow on the

magnetic needle.

Impatient of waiting, and having obtained very uncertain results from

an electric eel which had been brought to us alive, but much

enfeebled, we repaired to the Cano de Bera, to make our experiments in

the open air, and at the edge of the water. We set off on the 19th of

March, at a very early hour, for the village of Rastro; thence we were

conducted by the Indians to a stream, which, in the time of drought,

forms a basin of muddy water, surrounded by fine trees,* (* Amyris

lateriflora, A. coriacea, Laurus pichurin. Myroxylon secundum,

Malpighia reticulata.) the clusia, the amyris, and the mimosa with

fragrant flowers. To catch the gymnoti with nets is very difficult, on

account of the extreme agility of the fish, which bury themselves in

the mud. We would not employ the barbasco, that is to say, the roots

of the Piscidea erithyrna, the Jacquinia armillaris, and some species

of phyllanthus, which thrown into the pool, intoxicate or benumb the

eels. These methods have the effect of enfeebling the gymnoti. The

Indians therefore told us that they would "fish with horses,"

(embarbascar con caballos.* (* Meaning to excite the fish by horses.))

We found it difficult to form an idea of this extraordinary manner of

fishing; but we soon saw our guides return from the savannah, which

they had been scouring for wild horses and mules. They brought about

thirty with them, which they forced to enter the pool.

The extraordinary noise caused by the horses' hoofs, makes the fish

issue from the mud, and excites them to the attack. These yellowish

and livid eels, resembling large aquatic serpents, swim on the surface

of the water, and crowd under the bellies of the horses and mules. A

contest between animals of so different an organization presents a

very striking spectacle. The Indians, provided with harpoons and long

slender reeds, surround the pool closely; and some climb up the trees,

the branches of which extend horizontally over the surface of the

water. By their wild cries, and the length of their reeds, they

prevent the horses from running away and reaching the bank of the

pool. The eels, stunned by the noise, defend themselves by the

repeated discharge of their electric batteries. For a long interval

they seem likely to prove victorious. Several horses sink beneath the

violence of the invisible strokes which they receive from all sides,

in organs the most essential to life; and stunned by the force and

frequency of the shocks, they disappear under the water. Others,

panting, with mane erect, and haggard eyes expressing anguish and

dismay, raise themselves, and endeavour to flee from the storm by

which they are overtaken. They are driven back by the Indians into the

middle of the water; but a small number succeed in eluding the active

vigilance of the fishermen. These regain the shore, stumbling at every

step, and stretch themselves on the sand, exhausted with fatigue, and

with limbs benumbed by the electric shocks of the gymnoti.

In less than five minutes two of our horses were drowned. The eel

being five feet long, and pressing itself against the belly of the

horses, makes a discharge along the whole extent of its electric

organ. It attacks at once the heart, the intestines, and the caeliac

fold of the abdominal nerves. It is natural that the effect felt by

the horses should be more powerful than that produced upon man by the

touch of the same fish at only one of his extremities. The horses are

probably not killed, but only stunned. They are drowned from the

impossibility of rising amid the prolonged struggle between the other

horses and the eels.

We had little doubt that the fishing would terminate by killing

successively all the animals engaged; but by degrees the impetuosity

of this unequal combat diminished, and the wearied gymnoti dispersed.

They require a long rest, and abundant nourishment, to repair the

galvanic force which they have lost.* (* The Indians assured us that

when the horses are made to run two days successively into the same

pool, none are killed the second day. See, on the fishing for gymnoti

Views of Nature Bohn's edition page 18.) The mules and horses appear

less frightened; their manes are no longer bristled, and their eyes

express less dread. The gymnoti approach timidly the edge of the

marsh, where they are taken by means of small harpoons fastened to

long cords. When the cords are very dry the Indians feel no shock in

raising the fish into the air. In a few minutes we had five large

eels, most of which were but slightly wounded. Some others were taken,

by the same means, towards evening.

The temperature of the waters in which the gymnoti habitually live, is

from 26 to 27 degrees. Their electric force diminishes it is said, in

colder waters; and it is remarkable that, in general, animals endowed

with electromotive organs, the effects of which are sensible to man,

are not found in the air, but in a fluid that is a conductor of

electricity. The gymnotus is the largest of electrical fishes. I

measured some that were from five feet to five feet three inches long;

and the Indians assert that they have seen them still larger. We found

that a fish of three feet ten inches long weighed twelve pounds. The

transverse diameter of the body, without reckoning the anal fin, which

is elongated in the form of a keel, was three inches and a half. The

gymnoti of the Cano de Bera are of a fine olive-green. The under part

of the head is yellow mingled with red. Two rows of small yellow spots

are placed symmetrically along the back, from the head to the end of

the tail. Every spot contains an excretory aperture. In consequence,

the skin of the animal is constantly covered with a mucous matter,

which, as Volta has proved, conducts electricity twenty or thirty

times better than pure water. It is in general somewhat remarkable,

that no electric fish yet discovered in the different parts of the

world, is covered with scales.* (* We yet know with certainty only

seven electric fishes; Torpedo narke, Risso, T. unimaculata, T.

marmorata, T. galvanii, Silurus electricus, Tetraodon electricus,

Gymnotus electricus. It appears uncertain whether the Trichiurus

indicus has electrical properties or not. See Cuvier's Regne Animal

volume 2. But the genus Torpedo, very different from that of the rays

properly so called, has numerous species in the equatorial seas; and

it is probable that there exist several gymnoti specifically

different. The Indians mentioned to us a black and very powerful

species, inhabiting the marshes of the Apure, which never attains a

length of more than two feet, but which we were not able to procure.

The raton of the Rio de la Magdalena, which I have described under the

name of Gymnotus aequilabiatus (Observations de Zoologie volume 1)

forms a particular sub-genus. This is a Carapa, not scaly, and without

an electric organ. This organ is also entirely wanting in the

Brazilian Carapo, and in all the rays which were carefully examined by

Cuvier.)

The gymnoti, like our eels, are fond of swallowing and breathing air

on the surface of the water; but we must not thence conclude that the

fish would perish if it could not come up to breathe the air. The

European eel will creep during the night upon the grass; but I have

seen a very vigorous gymnotus that had sprung out of the water, die on

the ground. M. Provencal and myself have proved by our researches on

the respiration of fishes, that their humid bronchiae perform the

double function of decomposing the atmospheric air, and of

appropriating the oxygen contained in water. They do not suspend their

respiration in the air; but they absorb the oxygen like a reptile

furnished with lungs. It is known that carp may be fattened by being

fed, out of the water, if their gills are wet from time to time with

humid moss, to prevent them from becoming dry. Fish separate their

gill-covers wider in oxygen gas than in water. Their temperature

however, does not rise; and they live the same length of time in pure

vital air, and in a mixture of ninety parts nitrogen and ten oxygen.

We found that tench placed under inverted jars filled with air, absorb

half a cubic centimetre of oxygen in an hour. This action takes place

in the gills only; for fishes on which a collar of cork has been

fastened, and leaving their head out of the jar filled with air, do

not act upon the oxygen by the rest of their body.

The swimming-bladder of the gymnotus is two feet five inches long in a

fish of three feet ten inches.* (* Cuvier has shown that in the

Gymnotus electricus there exists, besides the large swimming-bladder,

another situated before it, and much smaller. It looks like the

bifurcated swimming-bladder in the Gymnotus aequilabiatus.) It is

separated by a mass of fat from the external skin; and rests upon the

electric organs, which occupy more than two-thirds of the animal's

body. The same vessels which penetrate between the plates or leaves of

these organs, and which cover them with blood when they are cut

transversely, also send out numerous branches to the exterior surface

of the air-bladder. I found in a hundred parts of the air of the

swimming-bladder four of oxygen and ninety-six of nitrogen. The

medullary substance of the brain displays but a feeble analogy with

the albuminous and gelatinous matter of the electric organs. But these

two substances have in common the great quantity of arterial blood

which they receive, and which is deoxidated in them. We may again

remark, on this occasion, that an extreme activity in the functions of

the brain causes the blood to flow more abundantly towards the head,

as the energy of the movement of the muscles accelerates the

deoxidation of the arterial blood. What a contrast between the

multitude and the diameter of the blood-vessels of the gymnotus, and

the small space occupied by its muscular system! This contrast reminds

the observer, that three functions of animal life, which appear in

other respects sufficiently distinct--the functions of the brain,

those of the electrical organ, and those of the muscles, all require

the afflux and concourse of arterial or oxygenated blood.

It would be temerity to expose ourselves to the first shocks of a very

large and strongly irritated gymnotus. If by chance a stroke be

received before the fish is wounded or wearied by long pursuit, the

pain and numbness are so violent that it is impossible to describe the

nature of the feeling they excite. I do not remember having ever

received from the discharge of a large Leyden jar, a more dreadful

shock than that which I experienced by imprudently placing both my

feet on a gymnotus just taken out of the water. I was affected during

the rest of the day with a violent pain in the knees, and in almost

every joint. To be aware of the difference that exists between the

sensation produced by the Voltaic battery and an electric fish, the

latter should be touched when they are in a state of extreme weakness.

The gymnoti and the torpedos then cause a twitching of the muscles,

which is propagated from the part that rests on the electric organs,

as far as the elbow. We seem to feel, at every stroke, an internal

vibration, which lasts two or three seconds, and is followed by a

painful numbness. Accordingly, the Tamanac Indians call the gymnotus,

in their expressive language, arimna, which means something that

deprives of motion.

The sensation caused by the feeble shocks of an electric eel appeared

to me analogous to that painful twitching with which I have been

seized at each contact of two heterogeneous metals applied to wounds

which I had made on my back by means of cantharides. This difference

of sensation between the effects of electric fishes and those of a

Voltaic battery or a Leyden jar feebly charged has struck every

observer; there is, however, nothing in this contrary to the

supposition of the identity of electricity and the galvanic action of

fishes. The electricity may be the same; but its effects will be

variously modified by the disposition of the electrical apparatus, by

the intensity of the fluid, by the rapidity of the current, and by the

particular mode of action.

In Dutch Guiana, at Demerara for instance, electric eels were formerly

employed to cure paralytic affections. At a time when the physicians

of Europe had great confidence in the effects of electricity, a

surgeon of Essequibo, named Van der Lott, published in Holland a

treatise on the medical properties of the gymnotus. These electric

remedies are practised among the savages of America, as they were

among the Greeks. We are told by Scribonius Largus, Galen, and

Dioscorides, that torpedos cure the headache and the gout. I did not

hear of this mode of treatment in the Spanish colonies which I

visited; and I can assert that, after having made experiments during

four hours successively with gymnoti, M. Bonpland and myself felt,

till the next day, a debility in the muscles, a pain in the joints,

and a general uneasiness, the effect of a strong irritation of the

nervous system.

The gymnotus is neither a charged conductor, nor a battery, nor an

electromotive apparatus, the shock of which is received every time

they are touched with one hand, or when both hands are applied to form

a conducting circle between the opposite poles. The electric action of

the fish depends entirely on its will; because it does not keep its

electric organs always charged, or whether by the secretion of some

fluid, or by any other means alike mysterious to us, it be capable of

directing the action of its organs to an external object. We often

tried, both insulated and otherwise, to touch the fish, without

feeling the least shock. When M. Bonpland held it by the head, or by

the middle of the body, while I held it by the tail, and, standing on

the moist ground, did not take each other's hand, one of us received

shocks, which the other did not feel. It depends upon the gymnotus to

direct its action towards the point where it finds itself most

strongly irritated. The discharge is then made at one point only, and

not at the neighbouring points. If two persons touch the belly of the

fish with their fingers, at an inch distance, and press it

simultaneously, sometimes one, sometimes the other, will receive the

shock. In the same manner, when one insulated person holds the tail of

a vigorous gymnotus, and another pinches the gills or pectoral fin, it

is often the first only by whom the shock is received. It did not

appear to us that these differences could be attributed to the dryness

or moisture of our hands, or to their unequal conducting power. The

gymnotus seemed to direct its strokes sometimes from the whole surface

of its body, sometimes from one point only. This effect indicates less

a partial discharge of the organ composed of an innumerable quantity

of layers, than the faculty which the animal possesses, (perhaps by

the instantaneous secretion of a fluid spread through the cellular

membrane,) of establishing the communication between its organs and

the skin only, in a very limited space.

Nothing proves more strongly the faculty, which the gymnotus

possesses, of darting and directing its stroke at will, than the

observations made at Philadelphia and Stockholm,* on gymnoti rendered

extremely tame. (* By MM. Williamson and Fahlberg. The following

account is given by the latter gentleman. "The gymnotus sent from

Surinam to M. Norderling, at Stockholm, lived more than four months in

a state of perfect health. It was twenty-seven inches long; and the

shocks it gave were so violent, especially in the open air, that I

found scarcely any means of protecting myself by non-conductors, in

transporting the fish from one place to another. Its stomach being

very small, it ate little at a time, but fed often. It approached

living fish, first sending them from afar a shock, the energy of which

was proportionate to the size of the prey. The gymnotus seldom failed

in its aim; one single stroke was almost always sufficient to overcome

the resistance which the strata of water, more or less thick according

to the distance, opposed to the electrical current. When very much

pressed by hunger, it sometimes directed the shocks against the person

who daily brought its food of boiled meat. Persons afflicted with

rheumatism came to touch it in hopes of being cured. They took it at

once by the neck and tail the shocks were in this case stronger than

when touched with one hand only. It almost entirely lost its

electrical power a short time before its death.") When they had been

made to fast a long time, they killed small fishes put into the tub.

They acted from a distance; that is to say, their electrical shock

passed through a very thick stratum of water. We need not be surprised

that what was observed in Sweden, on a single gymnotus only, we could

not perceive in a great number of individuals in their native country.

The electric action of animals being a vital action, and subject to

their will, it does not depend solely on their state of health and

vigour. A gymnotus that has been kept a long time in captivity,

accustoms itself to the imprisonment to which it is reduced; it

resumes by degrees the same habits in the tub, which it had in the

rivers and marshes. An electrical eel was brought to me at Calabozo:

it had been taken in a net, and consequently having no wound. It ate

meat, and terribly frightened the little tortoises and frogs which,

not aware of their danger, placed themselves on its back. The frogs

did not receive the stroke till the moment when they touched the body

of the gymnotus. When they recovered, they leaped out of the tub; and

when replaced near the fish, they were frightened at the mere sight of

it. We then observed nothing that indicated an action at a distance;

but our gymnotus, recently taken, was not yet sufficiently tame to

attack and devour frogs. On approaching the finger, or the metallic

points, very close to the electric organs, no shock was felt. Perhaps

the animal did not perceive the proximity of a foreign body; or, if it

did, we must suppose that in the commencement of its captivity,

timidity prevented it from darting forth its energetic strokes except

when strongly irritated by an immediate contact. The gymnotus being

immersed in water, I placed my hand, both armed and unarmed with

metal, within a very small distance from the electric organs; yet the

strata of water transmitted no shock, while M. Bonpland irritated the

animal strongly by an immediate contact, and received some very

violent shocks. Had we placed a very delicate electroscope in the

contiguous strata of water, it might possibly have been influenced at

the moment when the gymnotus seemed to direct its stroke elsewhere.

Prepared frogs, placed immediately on the body of a torpedo,

experience, according to Galvani, a strong contraction at every

discharge of the fish.

The electrical organ of the gymnoti acts only under the immediate

influence of the brain and the heart. On cutting a very vigorous fish

through the middle of the body, the fore part alone gave shocks. These

are equally strong in whatever part of the body the fish is touched;

it is most disposed, however, to emit them when the pectoral fin, the

electrical organ, the lips, the eyes, or the gills, are pinched.

Sometimes the animal struggles violently with a person holding it by

the tail, without communicating the least shock. Nor did I feel any

when I made a slight incision near the pectoral fin of the fish, and

galvanized the wound by the contact of two pieces of zinc and silver.

The gymnotus bent itself convulsively, and raised its head out of the

water, as if terrified by a sensation altogether new; but I felt no

vibration in the hands which held the two metals. The most violent

muscular movements are not always accompanied by electric discharges.

The action of the fish on the human organs is transmitted and

intercepted by the same bodies that transmit and intercept the

electrical current of a conductor charged by a Leyden jar, or Voltaic

battery. Some anomalies, which we thought we observed, are easily

explained, when we recollect that even metals (as is proved from their

ignition when exposed to the action of the battery) present a slight

obstacle to the passage of electricity; and that a bad conductor

annihilates the effect, on our organs, of a feeble electric charge,

whilst it transmits to us the effect of a very strong one. The

repulsive force which zinc and silver exercise together being far

superior to that of gold and silver, I have found that when a frog,

prepared and armed with silver, is galvanized under water, the

conducting arc of zinc produces contraction as soon as one of its

extremities approaches the muscles within three lines distance; while

an arc of gold does not excite the organs, when the stratum of water

between the gold and the muscles is more than half a line thick. In

the same manner, by employing a conducting arc composed of two pieces

of zinc and silver soldered together endways; and resting, as before,

one of the extremities of the metallic circuit on the femoral nerve,

it is necessary, in order to produce contractions, to bring the other

extremity of the conductor nearer and nearer to the muscles, in

proportion as the irritability of the organs diminishes. Toward the

end of the experiment the slightest stratum of water prevents the

passage of the electrical current, and it is only by the immediate

contact of the arc with the muscles, that the contractions take place.

These effects are, however, dependent on three variable circumstances;

the energy of the electromotive apparatus, the conductibility of the

medium, and the irritability of the organs which receive the

impressions: it is because experiments have not been sufficiently

multiplied with a view to these three variable elements, that, in the

action of electric eels and torpedos, accidental circumstances have

been taken for absolute conditions, without which the electric shocks

are not felt.

In wounded gymnoti, which give feeble but very equal shocks, these

shocks appeared to us constantly stronger on touching the body of the

fish with a hand armed with metal, than with the naked hand. They are

stronger also, when, instead of touching the fish with one hand,

naked, or armed with metal, we press it at once with both hands,

either naked or armed. These differences become sensible only when one

has gymnoti enough at disposal to be able to choose the weakest; and

when the extreme equality of the electric discharges admits of

distinguishing between the sensations felt alternately by the hand

naked or armed with a metal, by one or both hands naked, and by one or

both hands armed with metal. It is also in the case only of small

shocks, feeble and uniform, that they are more sensible on touching

the gymnotus with one hand (without forming a chain) with zinc, than

with copper or iron.

Resinous substances, glass, very dry wood, horn, and even bones, which

are generally believed to be good conductors, prevent the action of

the gymnoti from being transmitted to man. I was surprised at not

feeling the least shock on pressing wet sticks of sealing-wax against

the organs of the fish, while the same animal gave me the most violent

strokes, when excited by means of a metallic rod. M. Bonpland received

shocks, when carrying a gymnotus on two cords of the fibres of the

palm-tree, which appeared to us extremely dry. A strong discharge

makes its way through very imperfect conductors. Perhaps also the

obstacle which the conductor presents renders the discharge more

painful. I touched the gymnotus with a wet pot of brown clay, without

effect; yet I received violent shocks when I carried the gymnotus in

the same pot, because the contact was greater.

When two persons, insulated or otherwise, hold each other's hands, and

only one of these persons touches the fish with the hand, either naked

or armed with metal, the shock is most commonly felt by both at once.

However, it sometimes happens that, in the most severe shocks, the

person who comes into immediate contact with the fish alone feels

them. When the gymnotus is exhausted, or in a very reduced state of

excitability, and will no longer emit strokes on being irritated with

one hand, the shocks are felt in a very vivid manner, on forming the

chain, and employing both hands. Even then, however, the electric

shock takes place only at the will of the animal. Two persons, one of

whom holds the tail, and the other the head, cannot, by joining hands

and forming a chain, force the gymnotus to dart his stroke.

Though employing the most delicate electrometers in various ways,

insulating them on a plate of glass, and receiving very strong shocks

which passed through the electrometer, I could never discover any

phenomenon of attraction or repulsion. The same observation was made

by M. Fahlberg at Stockholm. That philosopher, however, has seen an

electric spark, as Walsh and Ingenhousz had before him, in London, by

placing the gymnotus in the air, and interrupting the conducting chain

by two gold leaves pasted upon glass, and a line distant from each

other. No person, on the contrary, has ever perceived a spark issue

from the body of the fish itself. We irritated it for a long time

during the night, at Calabozo, in perfect darkness, without observing

any luminous appearance. Having placed four gymnoti, of unequal

strength, in such a manner as to receive the shocks of the most

vigorous fish by contact, that is to say, by touching only one of the

other fishes, I did not observe that these last were agitated at the

moment when the current passed their bodies. Perhaps the current did

not penetrate below the humid surface of the skin. We will not,

however, conclude from this, that the gymnoti are insensible to

electricity; and that they cannot fight with each other at the bottom

of the pools. Their nervous system must be subject to the same agents

as the nerves of other animals. I have indeed seen, that, on laying

open their nerves, they undergo muscular contractions at the mere

contact of two opposite metals; and M. Fahlberg, of Stockholm, found

that his gymnotus was convulsively agitated when placed in a copper

vessel, and feeble discharges from a Leyden jar passed through its

skin.

After the experiments I had made on gymnoti, it became highly

interesting to me, on my return to Europe, to ascertain with precision

the various circumstances in which another electric fish, the torpedo

of our seas, gives or does not give shocks. Though this fish had been

examined by numerous men of science, I found all that had been

published on its electrical effects extremely vague. It has been very

arbitrarily supposed, that this fish acts like a Leyden jar, which may

be discharged at will, by touching it with both hands; and this

supposition appears to have led into error observers who have devoted

themselves to researches of this kind. M. Gay-Lussac and myself,

during our journey to Italy, made a great number of experiments on

torpedos taken in the gulf of Naples. These experiments furnish many

results somewhat different from those I collected on the gymnoti. It

is probable that the cause of these anomalies is owing rather to the

inequality of electric power in the two fishes, than to the different

disposition of their organs.

Though the power of the torpedo cannot be compared with that of the

gymnotus, it is sufficient to cause very painful sensations. A person

accustomed to electric shocks can with difficulty hold in his hands a

torpedo of twelve or fourteen inches, and in possession of all its

vigour. When the torpedo gives only very feeble strokes under water,

they become more sensible if the animal be raised above the surface. I

have often observed the same phenomenon in experimenting on frogs.

The torpedo moves the pectoral fins convulsively every time it emits a

stroke; and this stroke is more or less painful, according as the

immediate contact takes place by a greater or less surface. We

observed that the gymnotus gives the strongest shocks without making

any movement with the eyes, head, or fins.* (* The anal fin of the

gymnoti only has a sensible motion when these fishes are excited under

the belly, where the electric organ is placed.) Is this difference

caused by the position of the electric organ, which is not double in

the gymnoti? or does the movement of the pectoral fins of the torpedo

directly prove that the fish restores the electrical equilibrium by

its own skin, discharges itself by its own body, and that we generally

feel only the effect of a lateral shock?

We cannot discharge at will either a torpedo or a gymnotus, as we

discharge at will a Leyden jar or a Voltaic battery. A shock is not

always felt, even on touching the electric fish with both hands. We

must irritate it to make it give the shock. This action in the

torpedos, as well as in the gymnoti, is a vital action; it depends on

the will only of the animal, which perhaps does not always keep its

electric organs charged, or does not always employ the action of its

nerves to establish the chain between the positive and negative poles.

It is certain that the torpedo gives a long series of shocks with

astonishing celerity; whether it is that the plates or laminae of its

organs are not wholly exhausted, or that the fish recharges them

instantaneously.

The electric stroke is felt, when the animal is disposed to give it,

whether we touch with a single finger only one of the surfaces of the

organs, or apply both hands to the two surfaces, the superior and

inferior, at once. In either case it is altogether indifferent whether

the person who touches the fish with one finger or both hands be

insulated or not. All that has been said on the necessity of a

communication with the damp ground to establish a circuit, is founded

on inaccurate observations.

M. Gay-Lussac made the important observation that when an insulated

person touches the torpedo with one finger, it is indispensible that

the contact be direct. The fish may with impunity be touched with a

key, or any other metallic instrument; no shock is felt when a

conducting or non-conducting body is interposed between the finger and

the electrical organ of the torpedo. This circumstance proves a great

difference between the torpedo and the gymnotus, the latter giving his

strokes through an iron rod several feet long.

When the torpedo is placed on a metallic plate of very little

thickness, so that the plate touches the inferior surface of the

organs, the hand that supports the plate never feels any shock, though

another insulated person may excite the animal, and the convulsive

movement of the pectoral fins may denote the strongest and most

reiterated discharges.

If, on the contrary, a person support the torpedo placed upon a

metallic plate, with the left hand, as in the foregoing experiment,

and the same person touch the superior surface of the electrical organ

with the right hand, a strong shock is then felt in both arms. The

sensation is the same when the fish is placed between two metallic

plates, the edges of which do not touch, and the person applies both

hands at once to these plates. The interposition of one metallic plate

prevents the communication if that plate be touched with one hand

only, while the interposition of two metallic plates does not prevent

the shock when both hands are applied. In the latter case it cannot be

doubted that the circulation of the fluid is established by the two

arms.

If, in this situation of the fish between two plates, there exist any

immediate communication between the edges of these two plates, no

shock takes place. The chain between the two surfaces of the electric

organ is then formed by the plates, and the new communication,

established by the contact of the two hands with the two plates,

remains without effect. We carried the torpedo with impunity between

two plates of metal, and felt the strokes it gave only at the instant

when they ceased to touch each other at the edges.

Nothing in the torpedo or in the gymnotus indicates that the animal

modifies the electrical state of the bodies by which it is surrounded.

The most delicate electrometer is no way affected in whatever manner

it is employed, whether bringing it near the organs or insulating the

fish, covering it with a metallic plate, and causing the plate to

communicate by a conducting wire with the condenser of Volta. We were

at great pains to vary the experiments by which we sought to render

the electrical tension of the torpedo sensible; but they were

constantly without effect, and perfectly confirmed what M. Bonpland

and myself had observed respecting the gymnoti, during our abode in

South America.

Electrical fishes, when very vigorous, act with equal energy under

water and in the air. This observation led us to examine the

conducting property of water; and we found that, when several persons

form the chain between the superior and inferior surface of the organs

of the torpedo, the shock is felt only when these persons join hands.

The action is not intercepted if two persons, who support the torpedo

with their right hands, instead of taking one another by the left

hand, plunge each a metallic point into a drop of water placed on an

insulating substance. On substituting flame for the drop of water, the

communication is interrupted, and is only re-established, as in the

gymnotus, when the two points immediately touch each other in the

interior of the flame.

We are, doubtless, very far from having discovered all the secrets of

the electrical action of fishes which is modified by the influence of

the brain and the nerves; but the experiments we have just described

are sufficient to prove that these fishes act by a concealed

electricity, and by electromotive organs of a peculiar construction,

which are recharged with extreme rapidity. Volta admits that the

discharges of the opposite electricities in the torpedos and the

gymnoti are made by their own skin, and that when we touch them with

one hand only, or by means of a metallic point, we feel the effect of

a lateral shock, the electrical current not being directed solely the

shortest way. When a Leyden jar is placed on a wet woollen cloth

(which is a bad conductor), and the jar is discharged in such a manner

that the cloth makes part of the chain, prepared frogs, placed at

different distances, indicate by their contractions that the current

spreads itself over the whole cloth in a thousand different ways.

According to this analogy, the most violent shock given by the

gymnotus at a distance would be but a feeble part of the stroke which

re-establishes the equilibrium in the interior of the fish.* (* The

heterogeneous poles of the double electrical organs must exist in each

organ. Mr. Todd has recently proved, by experiments made on torpedos

at the Cape of Good Hope, that the animal continues to give violent

shocks when one of these organs is extirpated. On the contrary, all

electrical action is stopped (and this point, as elucidated by

Galvani, is of the greatest importance) if injury be inflicted on the

brain, or if the nerves which supply the plates of the electrical

organs be divided. In the latter case, the nerves being cut, and the

brain left untouched, the torpedo continues to live, and perform every

muscular movement. A fish, exhausted by too numerous electrical

discharges, suffered much more than another fish deprived, by dividing

the nerves, of any communication between the brain and the

electromotive apparatus. Philosophical Transactions 1816.) As the

gymnotus directs its stroke wherever it pleases, it must also be

admitted that the discharge is not made by the whole skin at once, but

that the animal, excited perhaps by the motion of a fluid poured into

one part of the cellular membrane, establishes at will the

communication between its organs and some particular part of the skin.

It may be conceived that a lateral stroke, out of the direct current,

must become imperceptible under the two conditions of a very weak

discharge, or a very great obstacle presented by the nature and length

of the conductor. Notwithstanding these considerations, it appears to

me very surprising that shocks of the torpedo, strong in appearance,

are not propagated to the hand when a very thin plate of metal is

interposed between it and the fish.

Schilling declared that the gymnotus approached the magnet

involuntarily. We tried in a thousand ways this supposed influence of

the magnet on the electrical organs, without having ever observed any

sensible effect. The fish no more approached the magnet, than a bar of

iron not magnetic. Iron-filings, thrown on its back, remained

motionless.

The gymnoti, which are objects of curiosity and of the deepest

interest to the philosophers of Europe, are at once dreaded and

detested by the natives. They furnish, indeed, in their muscular

flesh, pretty good aliment; but the electric organ fills the greater

part of their body, and this organ is slimy, and disagreeable to the

taste; it is accordingly separated with care from the rest of the eel.

The presence of gymnoti is also considered as the principal cause of

the want of fish in the ponds and pools of the Llanos. They, however,

kill many more than they devour: and the Indians told us, that when

young alligators and gymnoti are caught at the same time in very

strong nets, the latter never show the slightest trace of a wound,

because they disable the young alligators before they are attacked by

them. All the inhabitants of the waters dread the society of the

gymnoti. Lizards, tortoises, and frogs, seek pools where they are

secure from the electric action. It became necessary to change the

direction of a road near Uritucu, because the electric eels were so

numerous in one river, that they every year killed a great number of

mules, as they forded the water with their burdens.

Though in the present state of our knowledge we may flatter ourselves

with having thrown some light on the extraordinary effects of electric

fishes, yet a vast number of physical and physiological researches

still remain to be made. The brilliant results which chemistry has

obtained by means of the Voltaic battery, have occupied all observers,

and turned attention for some time from the examinations of the

phenomena of vitality. Let us hope that these phenomena, the most

awful and the most mysterious of all, will in their turn occupy the

earnest attention of natural philosophers. This hope will be easily

realized if they succeed in procuring anew living gymnoti in some one

of the great capitals of Europe. The discoveries that will be made on

the electromotive apparatus of these fish, much more energetic, and

more easy of preservation, than the torpedos,* will extend to all the

phenomena of muscular motion subject to volition. (* In order to

investigate the phenomena of the living electromotive apparatus in its

greatest simplicity, and not to mistake for general conditions

circumstances which depend on the degree of energy of the electric

organs, it is necessary to perform the experiments on those electrical

fishes most easily tamed. If the gymnoti were not known, we might

suppose, from the observations made on torpedos, that fishes cannot

give their shocks from a distance through very thick strata of water,

or through a bar of iron, without forming a circuit. Mr. Williamson

has felt strong shocks when he held only one hand in the water, and

this hand, without touching the gymnotus, was placed between it and

the small fish towards which the stroke was directed from ten or

fifteen inches distance. Philosophical Transactions volume 65 pages 99

and 108. When the gymnotus was enfeebled by bad health, the lateral

shock was imperceptible; and in order to feel the shock, it was

necessary to form a chain, and touch the fish with both hands at once.

Cavendish, in his ingenious experiments on an artificial torpedo, had

well remarked these differences, depending on the greater or less

energy of the charge. Philosophical Transactions 1776 page 212.) It

will perhaps be found that, in most animals, every contraction of the

muscular fibre is preceded by a discharge from the nerve into the

muscle; and that the mere simple contact of heterogeneous substances

is a source of movement and of life in all organized beings. Did an

ingenious and lively people, the Arabians, guess from remote

antiquity, that the same force which inflames the vault of Heaven in

storms, is the living and invisible weapon of inhabitants of the

waters? It is said, that the electric fish of the Nile bears a name in

Egypt, that signifies thunder.* (* It appears, however, that a

distinction is to be made between rahd, thunder, and rahadh, the

electrical fish; and that this latter word means simply that which

causes trembling.)

We left the town of Calabozo on the 24th of March, highly satisfied

with our stay, and the experiments we had made on an object so worthy

of the attention of physiologists. I had besides obtained some good

observations of the stars; and discovered with surprise, that the

errors of maps amounted here also to a quarter of a degree of

latitude. No person had taken an observation before me on this spot;

and geographers, magnifying as usual the distance from the coast to

the islands, have carried back beyond measure all the localities

towards the south.

As we advanced into the southern part of the Llanos, we found the

ground more dusty, more destitute of herbage, and more cracked by the

effect of long drought. The palm-trees disappeared by degrees. The

thermometer kept, from eleven in the morning till sunset, at 34 or 35

degrees. The calmer the air appeared at eight or ten feet high, the

more we were enveloped in those whirlwinds of dust, caused by the

little currents of air that sweep the ground. About four o'clock in

the afternoon, we found a young Indian girl stretched upon the

savannah. She was almost in a state of nudity, and appeared to be

about twelve or thirteen years of age. Exhausted with fatigue and

thirst, her eyes, nostrils, and mouth filled with dust, she breathed

with a rattling in her throat, and was unable to answer our questions.

A pitcher, overturned, and half filled with sand, was lying at her

side. Happily one of our mules was laden with water; and we roused the

girl from her lethargic state by bathing her face, and forcing her to

drink a few drops of wine. She was at first alarmed on seeing herself

surrounded by so many persons; but by degrees she took courage, and

conversed with our guides. She judged, from the position of the sun,

that she must have remained during several hours in that state of

lethargy. We could not prevail on her to mount one of our beasts of

burden, and she would not return to Uritucu. She had been in service

at a neighbouring farm; and she had been discharged, because at the

end of a long sickness she was less able to work than before. Our

menaces and prayers were alike fruitless; insensible to suffering,

like the rest of her race, she persisted in her resolution of going to

one of the Indian Missions near the city of Calabozo. We removed the

sand from her pitcher, and filled it with water. She resumed her way

along the steppe, before we had remounted our horses, and was soon

separated from us by a cloud of dust. During the night we forded the

Rio Uritucu, which abounds with a breed of crocodiles remarkable for

their ferocity. We were advised to prevent our dogs from going to

drink in the rivers, for it often happens that the crocodiles of

Uritucu come out of the water, and pursue dogs upon the shore. This

intrepidity is so much the more striking, as at eight leagues

distance, the crocodiles of the Rio Tisnao are extremely timid, and

little dangerous. The manners of animals vary in the same species

according to local circumstances difficult to be determined. We were

shown a hut, or rather a kind of shed, in which our host of Calabozo,

Don Miguel Cousin, had witnessed a very extraordinary scene. Sleeping

with one of his friends on a bench or couch covered with leather, Don

Miguel was awakened early in the morning by a violent shaking and a

horrible noise. Clods of earth were thrown into the middle of the hut.

Presently a young crocodile two or three feet long issued from under

the bed, darted at a dog which lay on the threshold of the door, and,

missing him in the impetuosity of his spring, ran towards the beach to

gain the river. On examining the spot where the barbacoa, or couch,

was placed, the cause of this strange adventure was easily discovered.

The ground was disturbed to a considerable depth. It was dried mud,

which had covered the crocodile in that state of lethargy, or

summer-sleep, in which many of the species lie during the absence of

the rains in the Llanos. The noise of men and horses, perhaps the

smell of the dog, had aroused the crocodile. The hut being built at

the edge of the pool, and inundated during part of the year, the

crocodile had no doubt entered, at the time of the inundation of the

savannahs, by the same opening at which it was seen to go out. The

Indians often find enormous boas, which they call uji, or

water-serpents,* in the same lethargic state. (* Culebra de agua,

named by the common people traga-venado, the swallower of stags. The

word uji belongs to the Tamanac language.) To reanimate them, they

must be irritated, or wetted with water. Boas are killed, and immersed

in the streams, to obtain, by means of putrefaction, the tendinous

parts of the dorsal muscles, of which excellent guitar-strings are

made at Calabozo, preferable to those furnished by the intestines of

the alouate monkeys.

The drought and heat of the Llanos act like cold upon animals and

plants. Beyond the tropics the trees lose their leaves in a very dry

air. Reptiles, particularly crocodiles and boas, having very indolent

habits, leave with reluctance the basins in which they have found

water at the period of great inundations. In proportion as the pools

become dry, these animals penetrate into the mud, to seek that degree

of humidity which gives flexibility to their skin and integuments. In

this state of repose they are seized with stupefaction; but possibly

they preserve a communication with the external air; and, however

little that communication may be, it possibly suffices to keep up the

respiration of an animal of the saurian family, provided with enormous

pulmonary sacs, exerting no muscular motion, and in which almost all

the vital functions are suspended. It is probable that the mean

temperature of the dried mud, exposed to the solar rays, is more than

40 degrees. When the north of Egypt, where the coolest month does not

fall below 13.4 degrees, was inhabited by crocodiles, they were often

found torpid with cold. They were subject to a winter-sleep, like the

European frog, lizard, sand-martin, and marmot. If the hibernal

lethargy be observed, both in cold-blooded and in hot-blooded animals,

we shall be less surprised to learn, that these two classes furnish

alike examples of a summer-sleep. In the same manner as the crocodiles

of South America, the tanrecs, or Madagascar hedgehogs, in the midst

of the torrid zone, pass three months of the year in lethargy.

On the 25th of March we traversed the smoothest part of the steppes of

Caracas, the Mesa de Pavones. It is entirely destitute of the corypha

and moriche palm-trees. As far as the eye can reach, not a single

object fifteen inches high can be discovered. The air was clear, and

the sky of a very deep blue; but the horizon reflected a livid and

yellowish light, caused no doubt by the quantity of sand suspended in

the atmosphere. We met some large herds of cattle, and with them

flocks of birds of a black colour with an olive shade. They are of the

genus Crotophaga,* and follow the cattle. (* The Spanish colonists

call the Crotophaga ani, zamurito (little carrion vulture--Vultur aura

minuta), or garapatero, the eater of garaparas, insects of the Acarus

family.) We had often seen them perched on the backs of cows, seeking

for gadflies and other insects. Like many birds of these desert

places, they fear so little the approach of man, that children often

catch them in their hands. In the valleys of Aragua, where they are

very common, we have seen them perch upon the hammocks on which we

were reposing, in open day.

We discover, between Calabozo, Uritucu, and the Mesa de Pavones,

wherever there are excavations of some feet deep, the geological

constitution of the Llanos. A formation of red sandstone (ancient

conglomerate) covers an extent of several thousand square leagues. We

shall find it again in the vast plains of the Amazon, on the eastern

boundary of the province of Jaen de Bracamoros. This prodigious

extension of red sandstone in the low grounds stretching along the

east of the Andes, is one of the most striking phenomena I observed

during my examination of rocks in the equinoctial regions.

The red sandstone of the Llanos of Caracas lies in a concave position,

between the primitive mountains of the shore and of Parime. On the

north it is backed by the transition-slates,* (* At Malpaso and

Piedras Azules.) and on the south it rests immediately on the granites

of the Orinoco. We observed in it rounded fragments of quartz

(kieselschiefer), and Lydian stone, cemented by an olive-brown

ferruginous clay. The cement is sometimes of so bright a red that the

people of the country take it for cinnabar. We met a Capuchin monk at

Calabozo, who was in vain attempting to extract mercury from this red

sandstone. In the Mesa de Paja this rock contains strata of another

quartzose sandstone, very fine-grained; more to the south it contains

masses of brown iron, and fragments of petrified trees of the

monocotyledonous family, but we did not see in it any shells. The red

sandstone, called by the Llaneros, the stone of the reefs (piedra de

arrecifes), is everywhere covered with a stratum of clay. This clay,

dried and hardened in the sun, splits into separate prismatic pieces

with five or six sides. Does it belong to the trap-formation of

Parapara? It becomes thicker, and mixed with sand, as we approach the

Rio Apure; for near Calabozo it is one toise thick, near the mission

of Guayaval five toises, which may lead to the belief that the strata

of red sandstone dips towards the south. We gathered in the Mesa de

Pavones little nodules of blue iron-ore disseminated in the clay.

A dense whitish-gray limestone, with a smooth fracture, somewhat

analogous to that of Caripe, and consequently to that of Jura, lies on

the red sandstone between Tisnao and Calabozo.* (* Does this formation

of secondary limestone of the Llanos contain galena? It has been found

in strata of black marl, at Barbacoa, between Truxillo and

Barquesimeto, north-west of the Llanos.) In several other places, for

instance in the Mesa de San Diego, and between Ortiz and the Mesa de

Paja,* (* Also near Cachipe and San Joacquim, in the Llanos of

Barcelona.) we find above the limestone lamellar gypsum alternating

with strata of marl. Considerable quantities of this gypsum are sent

to the city of Caracas,* which is situated amidst primitive mountains.

(* This trade is carried on at Parapara. A load of eight arrobas sells

at Caracas for twenty-four piastres.)

This gypsum generally forms only small beds, and is mixed with a great

deal of fibrous gypsum. Is it of the same formation as that of Guire,

on the coast of Paria, which contains sulphur? or do the masses of

this latter substance, found in the valley of Buen Pastor and on the

banks of the Orinoco, belong, with the argillaceous gypsum of the

Llanos, to a secondary formation much more recent.

These questions are very interesting in the study of the relative

antiquity of rocks, which is the principal basis of geology. I know

not of any salt-deposits in the Llanos. Horned cattle prosper here

without those famous bareros, or muriatiferous lands, which abound in

the Pampas of Buenos Ayres.* (* Known in North America under the name

of salt-licks.)

After having wandered for a long time, and without any traces of a

road, in the desert savannahs of the Mesa de Pavones, we were

agreeably surprised when we came to a solitary farm, the Hato de Alta

Gracia, surrounded with gardens and basins of limpid water. Hedges of

bead-trees encircled groups of icacoes laden with fruit. Farther on we

passed the night near the small village of San Geronymo del Guayaval,

founded by Capuchin missionaries. It is situated near the banks of the

Rio Guarico, which falls into the Apure. I visited the missionary, who

had no other habitation than his church, not having yet built a house.

He was a young man, and he received us in the most obliging manner,

giving us all the information we desired. His village, or to use the

word established among the monks, his Mission, was not easy to govern.

The founder, who had not hesitated to establish for his own profit a

pulperia, in other words, to sell bananas and guarapo in the church

itself, had shown himself to be not very nice in the choice of the new

colonists. Many marauders of the Llanos had settled at Guayaval,

because the inhabitants of a Mission are exempt from the authority of

secular law. Here, as in Australia, it cannot be expected that good

colonists will be formed before the second or third generation.

We passed the Guarico, and encamped in the savannahs south of

Guayaval. Enormous bats, no doubt of the tribe of Phyllostomas,

hovered as usual over our hammocks during a great part of the night.

Every moment they seemed to be about to fasten on our faces. Early in

the morning we pursued our way over low grounds, often inundated. In

the season of rains, a boat may be navigated, as on a lake, between

the Guarico and the Apure. We arrived on the 27th of March at the

Villa de San Fernando, the capital of the Mission of the Capuchins in

the province of Varinas. This was the termination of our journey over

the Llanos; for we passed the three months of April, May, and June on

the rivers.