Personal Narrative of Travels to the Equinoctial Regions of America, During the Years 1799-1804, Vol.3 — 12 - Chapter 3.26, Part 5

We continued our passage on the following day; and were surprised at the depth of the channels between the Caracas Islands, where the sloop worked her way through them almost touching the rocks.

How much do these calcareous islets, of which the form and direction call to mind the great catastrophe that separated from them the mainland, differ in aspect from the volcanic archipelago on the north of Lanzerote where the hills of basalt seem to have been heaved up from the bottom of the sea!

Numbers of pelicans and of flamingos, which fished in the nooks or harassed the pelicans in order to seize their prey, indicated our approach to the coast of Cumana.

It is curious to observe at sunrise how the sea-birds suddenly appear and animate the scene, reminding us, in the most solitary regions, of the activity of our cities at the dawn of day.

At nine in the morning we reached the gulf of Cariaco which serves as a roadstead to the town of Cumana.

The hill, crowned by the castle of San Antonio, stood out, prominent from its whiteness, on the dark curtain of the inland mountains.

We gazed with interest on the shore, where we first gathered plants in America, and where, some months later, M. Bonpland had been in such danger.

Among the cactuses, that rise in columns twenty feet high, appear the Indian huts of the Guaykeries.

Every part of the landscape was familiar to us; the forest of cactus, the scattered huts and that enormous ceiba, beneath which we loved to bathe at the approach of night.

Our friends at Cumana came out to meet us: men of all castes, whom our frequent herborizations had brought into contact with us, expressed the greater joy at sight of us, as a report that we had perished on the banks of the Orinoco had been current for several months.

These reports had their origin either in the severe illness of M. Bonpland, or in the fact of our boat having been nearly lost in a gale above the mission of Uruana.

We hastened to visit the governor, Don Vicente Emparan, whose recommendations and constant solicitude had been so useful to us during the long journey we had just terminated.

He procured for us, in the centre of the town, a house which, though perhaps too lofty in a country exposed to violent earthquakes, was extremely useful for our instruments.

We enjoyed from its terraces a majestic view of the sea, of the isthmus of Araya, and the archipelago of the islands of Caracas, Picuita and Borracha.

The port of Cumana was every day more and more closely blockaded, and the vain expectation of the arrival of Spanish packets detained us two months and a half longer.

We were often nearly tempted to go to the Danish islands which enjoyed a happy neutrality; but we feared that, if we left the Spanish colonies, we might find some obstacles to our return.

With the ample freedom which in a moment of favour had been granted to us, we did not consider it prudent to hazard anything that might give umbrage to the local authorities.

We employed our time in completing the Flora of Cumana, geologically examining the eastern part of the peninsula of Araya, and observing many eclipses of satellites, which confirmed the longitude of the place already obtained by other means.

We also made experiments on the extraordinary refractions, on evaporation and on atmospheric electricity.

The living animals which we had brought from the Orinoco were objects of great curiosity to the inhabitants of Cumana.

The capuchin of the Esmeralda (Simia chiropotes), which so much resembles man in the expression of its physiognomy; and the sleeping monkey (Simia trivirgata), which is the type of a new group; had never yet been seen on that coast.

We destined them for the menagerie of the Jardin des Plantes at Paris.

The arrival of a French squadron which had failed in an attack upon Curacao furnished us, unexpectedly, with an excellent opportunity for sending them to Guadaloupe; and General Jeannet, together with the commissary Bresseau, agent of the executive power at the Antilles, promised to convey them.

The monkeys and birds died at Guadaloupe but fortunately the skin of the Simia chiropotes, the only one in Europe, was sent a few years ago to the Jardin des Plantes, where the couxio (Simia satanas) and the stentor or alouate of the steppes of Caracas (Simia ursina) had been already received.

The arrival of so great a number of French military officers and the manifestation of political and religious opinions not altogether conformable with the interests of the governments of Europe excited singular agitation in the population of Cumana.

The governor treated the French authorities with the forms of civility consistent with the friendly relations subsisting at that period between France and Spain.

In the streets the coloured people crowded round the agent of the French Directory, whose dress was rich and theatrical.

White men, too, with indiscreet curiosity, whenever they could make themselves understood, made enquiries concerning the degree of influence granted by the republic to the colonists in the government of Guadaloupe.

The king's officers doubled their zeal in furnishing provision for the little squadron.

Strangers, who boasted that they were free, appeared to these people troublesome guests; and in a country of which the growing prosperity depended on clandestine communication with the islands, and on a freedom of trade forced from the ministry, the European Spaniards extolled the wisdom of the old code of laws (leyes de Indias) which permitted the entrance of foreign vessels into their ports only in extreme cases of want or distress.

These contrasts between the restless desires of the colonists and the distrustful apathy of the government, throw some light on the great political events which, after long preparation, have separated Spain from her colonies.

We again passed a few agreeable days, from the third to the fifth of November, at the peninsula of Araya, situated beyond the gulf of Cariaco, opposite to Cumana.

* (* I have already described the pearls of Araya; its sulphurous deposits and submarine springs of liquid and colourless petroleum.

See volume 1. 5. ) We were informed that the Indians carried to the town from time to time considerable quantities of native alum, found in the neighbouring mountains.

The specimens shown to us sufficiently indicated that it was neither alunite, similar to the rock of Tolfa and Piombino, nor those capillary and silky salts of alkaline sulphate of alumina and magnesia that line the clefts and cavities of rocks, but real masses of native alum, with a conchoidal or imperfectly lamellar fracture.

We were led to hope that we should find the mine of alum (mina de alun) in the slaty cordillera of Maniquarez, and so new a geological phenomenon was calculated to rivet our attention.

The priest Juan Gonzales, and the treasurer, Don Manuel Navarete, who had been useful to us from our first arrival on this coast, accompanied us in our little excursion.

We disembarked near Cape Caney and again visited the ancient salt-pit (which is converted into a lake by the irruption of the sea), the fine ruins of the castle of Araya and the calcareous mountain of the Barigon, which, from its steepness on the western side is somewhat difficult of access.

Muriatiferous clay mixed with bitumen and lenticular gypsum and sometimes passing to a darkish brown clay, devoid of salt, is a formation widely spread through this peninsula, in the island of Margareta and on the opposite continent, near the castle of San Antonio de Cumana.

Probably the existence of this formation has contributed to produce those ruptures and rents in the ground which strike the eye of the geologist when he stands on one of the eminences of the peninsula of Araya.

The cordillera of this peninsula, composed of mica-slate and clay-slate, is separated on the north from the chain of mountains of the island of Margareta (which are of a similar composition) by the channel of Cubagua; and on the south it is separated from the lofty calcareous chain of the continent, by the gulf of Cariaco.

The whole intermediate space appears to have been heretofore filled with muriatiferous clay; and no doubt the continual erosions of the ocean have removed this formation and converted the plain, first into lakes, then into gulfs, and finally into navigable channels.

The account of what has passed in the most modern times at the foot of the castle of Araya, the irruption of the sea into the ancient salt-pit, the formation of the laguna de Chacopata and a lake, four leagues in length, which cuts the island of Margareta nearly into two parts, afford evident proofs of these successive erosions.

In the singular configuration of the coasts in the Morro of Chacopata; in the little islands of the Caribbees, the Lobos and Tunal; in the great island of Coche, and the capes of Carnero and Mangliers there still seem to be apparent the remains of an isthmus which, stretching from north to south, formerly joined the peninsula of Araya to the island of Margareta.

In that island a neck of very low land, three thousand toises long, and less than two hundred toises broad, conceals on the northern sides the two hilly groups, known by the names of La Vega de San Juan and the Macanao.

The Laguna Grande of Margareta has a very narrow opening to the south and small boats pass by portage over the neck of land or northern dyke.

Though the waters on these shores seem at present to recede from the continent it is nevertheless very probable that in the lapse of ages, either by an earthquake or by a sudden rising of the ocean, the long island of Margareta will be divided into two rocky islands of a trapezoidal form.

The limestone of the Barigon, which is a part of the great formation of sandstone or calcareous breccia of Cumana, is filled with fossil shells in as perfect preservation as those of other tertiary limestones in France and Italy.

We detached some blocks containing oysters eight inches in diameter, pectens, venuses, and lithophyte polypi.

I recommend to naturalists better versed in the knowledge of fossils than I then was, to examine with care this mountainous coast (which is easy of access to European vessels) in their way to Cumana, Guayra or Curacao.

It would be curious to discover whether any of these shells and these species of petrified zoophytes still inhabit the seas of the West Indies, as M. Bonpland conjectured, and as is the case in the island of Timor and perhaps in Guadaloupe.

We sailed on the 4th of November, at one o'clock in the morning, in search of the mine of native alum.

I took with me the chronometer and my large Dollond telescope, intending to observe at the Laguna Chica (Small Lake), east of the village of Maniquarez, the immersion of the first satellite of Jupiter; this design, however, was not accomplished, contrary winds having prevented our arrival before daylight.

The spectacle of the phosphorescence of the ocean and the sports of the porpoises which surrounded our canoe somewhat atoned for this disappointment.

We again passed those spots where springs of petroleum gush from mica-slate at the bottom of the sea and the smell of which is perceptible from a considerable distance.

When it is recollected that farther eastward, near Cariaco, the hot and submarine waters are sufficiently abundant to change the temperature of the gulf at its surface, we cannot doubt that the petroleum is the effect of distillation at an immense depth, issuing from those primitive rocks beneath which lies the focus of all volcanic commotion.

The Laguna Chica is a cove surrounded by perpendicular mountains, and connected with the gulf of Cariaco only by a narrow channel twenty-five fathoms deep.

It seems, like the fine port of Acapulco, to owe its existence to the effect of an earthquake.

A beach shows that the sea is here receding from the land, as on the opposite coast of Cumana.

The peninsula of Araya, which narrows between Cape Mero and Cape las Minas to one thousand four hundred toises, is little more than four thousand toises in breadth near the Laguna Chica, reckoning from one sea to the other.

We had to cross this distance in order to find the native alum and to reach the cape called the Punta de Chuparuparu.

The road is difficult only because no path is traced; and between precipices of some depth we were obliged to step over ridges of bare rock, the strata of which are much inclined.

The principal point is nearly two hundred and twenty toises high; but the mountains, as it often happens in a rocky isthmus, display very singular forms.

The Paps (tetas) of Chacopata and Cariaco, midway between the Laguna Chica and the town of Cariaco, are peaks which appear isolated when viewed from the platform of the castle of Cumana.

The vegetable earth in this country is only thirty toises above sea level.

Sometimes there is no rain for the space of fifteen months; if, however, a few drops fall immediately after the flowering of the melons and gourds, they yield fruit weighing from sixty to seventy pounds, notwithstanding the apparent dryness of the air.

I say apparent dryness, for my hygrometric observations prove that the atmosphere of Cumana and Araya contains nearly nine-tenths of the quantity of watery vapour necessary to its perfect saturation.

It is this air, at once hot and humid, that nourishes those vegetable reservoirs, the cucurbitaceous plants, the agaves and melocactuses half-buried in the sand.

When we visited the peninsula the preceding year there was a great scarcity of water; the goats for want of grass died by hundreds.

During our stay at the Orinoco the order of the seasons seemed to be entirely changed.

At Araya, Cochen, and even in the island of Margareta it had rained abundantly; and those showers were remembered by the inhabitants in the same way as a fall of aerolites would be noted in the recollection of the naturalists of Europe.

The Indian who was our guide scarcely knew in what direction we should find the alum; he was ignorant of its real position.

This ignorance of localities characterises almost all the guides here, who are chosen from among the most indolent class of the people.

We wandered for eight or nine hours among rocks totally bare of vegetation.

The mica-slate passes sometimes to clay-slate of a darkish grey.

I was again struck by the extreme regularity in the direction and inclination of the strata.

They run north 50 degrees east, inclining from 60 to 70 degrees north-west.

This is the general direction which I had observed in the gneiss-granite of Caracas and the Orinoco, in the hornblende-slates of Angostura, and even in the greater part of the secondary rocks we had just examined.

The beds, over a vast extent of land, make the same angle with the meridian of the place; they present a parallelism, which may be considered as one of the great geologic laws capable of being verified by precise measures.

Advancing toward Cape Chuparuparu, the veins of quartz that cross the mica-slate increase in size.

We found some from one to two toises broad, full of small fasciculated crystals of rutile titanite.

We sought in vain for cyanite, which we had discovered in some blocks near Maniquarez.

Farther on the mica-state presents not veins, but little beds of graphite or carburetted iron.

They are from two to three inches thick and have precisely the same direction and inclination as the rock.

Graphite, in primitive soils, marks the first appearance of carbon on the globe--that of carbon uncombined with hydrogen.

It is anterior to the period when the surface of the earth became covered with monocotyledonous plants.

From the summit of those wild mountains there is a majestic view of the island of Margareta.

Two groups of mountains already mentioned, those of Macanao and La Vega de San Juan, rise from the bosom of the waters.

The capital of the island, La Asuncion, the port of Pampatar, and the villages of Pueblo de la Mar, Pueblo del Norte and San Juan belong to the second and most easterly of these groups.

The western group, the Macanao, is almost entirely uninhabited.

The isthmus that divides these large masses of mica-slate was scarcely visible; its form appeared changed by the effect of the mirage and we recognized the intermediate part, through which runs the Laguna Grande, only by two small hills of a sugarloaf form, in the meridian of the Punta de Piedras.

Nearer we look down on the small desert archipelago of the four Morros del Tunal, the Caribbee and the Lobos Islands.

After much vain search we at length found, before we descended to the northern coast of the peninsula of Araya, in a ravine of very difficult access (Aroyo del Robalo), the mineral which had been shown to us at Cumana.

The mica-slate changed suddenly into carburetted and shining clay-slate.

It was an ampelite; and the waters (for there are small springs in those parts, and some have recently been discovered near the village of Maniquarez) were impregnated with yellow oxide of iron and had a styptic taste.

We found the sides of the neighbouring rocks lined with capillary sulphate of alumina in effervescence; and real beds, two inches thick, full of native alum, extending as far as the eye could reach in the clay slate.

The alum is greyish white, somewhat dull on the surface and of an almost glassy lustre internally.

Its fracture is not fibrous but imperfectly conchoidal.

It is slightly translucent when its fragments are thin; and has a sweetish and astringent taste without any bitter mixture.

When on the spot, I proposed to myself the question whether this alum, so pure, and filling beds in the clay-slate without leaving the smallest void, be of a formation contemporary with the rock, or whether it be of a recent, and in some sort secondary, origin, like the muriate of soda, found sometimes in small veins, where strongly concentrated springs traverse beds of gypsum or clay.

In these parts nothing seems to indicate a process of formation likely to be renewed in our days.

The slaty rock exhibits no open cleft; and none is found parallel with the direction of the slates.

It may also be inquired whether this aluminous slate be a transition-formation lying on the primitive mica-slate of Araya, or whether it owe its origin merely to a change of composition and texture in the beds of mica-slate.

I lean to the latter proposition; for the transition is progressive, and the clay-slate (thonschiefer) and mica-slate appear to me to constitute here but one formation.

The presence of cyanite, rutile-titanite, and garnets, and the absence of Lydian stone, and all fragmentary or arenaceous rocks, seem to characterise the formation we describe as primitive.

It is asserted that even in Europe ampelite and green stone are found, though rarely, in slates anterior to transition-slate.

When, in 1785, after an earthquake, a great rocky mass was broken off in the Aroyo del Robalo, the Guaykeries of Los Serritos collected fragments of alum five or six inches in diameter, extremely pure and transparent.

It was sold in my time at Cumana to the dyers and tanners, at the price of two reals* per pound, while alum from Spain cost twelve reals.

(* The real is about 6 1/2 English pence.

) This difference of price was more the result of prejudice and of the impediments to trade, than of the inferior quality of the alum of the country, which is fit for use without undergoing any purification.

It is also found in the chain of mica-slate and clay-slate, on the north-west coast of the island of Trinidad, at Margareta and near Cape Chuparuparu, north of the Cerro del Distiladero.

* (* Another place was mentioned to us, west of Bordones, the Puerto Escondido.

But that coast appeared to me to be wholly calcareous; and I cannot conceive where could be the situation of ampelite and native alum on this point.

Was it in the beds of slaty clay that alternate with the alpine limestone of Cumanacoa?

Fibrous alum is found in Europe only in formations posterior to those of transition, in lignites and other tertiary formations belonging to the lignites.

) The Indians, who are naturally addicted to concealment, are not inclined to make known the spots whence they obtain native alum; but it must be abundant, for I have seen very considerable quantities of it in their possession at a time.

South America at present receives its alum from Europe, as Europe in its turn received it from the natives of Asia previous to the fifteenth century.

Mineralogists, before my travels, knew no substances which, without addition, calcined or not calcined, could directly yield alum (sulphate of alumina and potash), except rocks of trachytic formation, and small veins traversing beds of lignite and bituminous wood.

Both these substances, so different in their origin, contain all that constitutes alum, that is to say, alumina, sulphuric acid and potash.

The ores of Tolfa, Milo and Nipoligo; those of Montione, in which silica does not accompany the alumina; the siliceous breccia of Mont Dore, which contains sulphur in its cavities; the alumiferous rocks of Parad and Beregh in Hungary, which belong also to trachytic and pumice conglomerates, may no doubt be traced to the penetration of sulphurous acid vapours.

They are the products of a feeble and prolonged volcanic action, as may be easily ascertained in the solfataras of Puzzuoli and the Peak of Teneriffe.

The alumite of Tolfa, which, since my return to Europe, I have examined on the spot, conjointly with Gay-Lussac, has, by its oryctognostic characters and its chemical composition, a considerable affinity to compact feldspar, which constitutes the basis of so many trachytes and transition-porphyries.

It is a siliciferous subsulphate of alumina and potash, a compact feldspar, with the addition of sulphuric acid completely formed in it.

The waters circulating in these alumiferous rocks of volcanic origin do not, however, deposit masses of native alum, to yield which the rocks must be roasted.

I

know not of any deposits analogous to those I brought from Cumana; for the capillary and fibrous masses found in veins traversing beds of lignites (as on the banks of the Egra, between Saatz and Commothau in Bohemia), or efflorescing in cavities (as at Freienwalde in Brandenburg, and at Segario in Sardinia), are impure salts, often destitute of potash, and mixed with the sulphates of ammonia and magnesia.

A slow decomposition of the pyrites, which probably act as so many little galvanic piles, renders the waters alumiferous, that circulate across the bituminous lignites and carburetted clays.

These waters, in contact with carbonate of lime, even give rise to the deposits of subsulphate of alumina (destitute of potash), found near Halle, and formerly believed erroneously to be pure alumina belonging, like the porcelain earth (kaolin) of Morl, to porphyry of red sandstone.

Analogous chemical actions may take place in primitive and transition slates as well as in tertiary formations.

All slates, and this fact is very important, contain nearly five per cent of potash, sulphuret of iron, peroxide of iron, carbon, etc. The contact of so many moistened heterogeneous substances must necessarily lead them to a change of state and composition.

The efflorescent salts that abundantly cover the aluminous slates of Robalo, show how much these chemical effects are favoured by the high temperature of the climate;

but, I repeat, in a rock where there are no crevices, no vacuities parallel to the direction and inclination of the strata, native alum, semitransparent and of conchoidal fracture, completely filling its place (its beds), must be regarded as of the same age with the rock in which it is contained.

The term contemporary formation is here taken in the sense attached to it by geologists, in speaking of beds of quartz in clay-slate, granular limestone in mica-slate or feldspar in gneiss.

After having for a long time wandered over barren scenes amidst rocks entirely devoid of vegetation, our eyes dwelt with pleasure on tufts of malpighia and croton, which we found in descending toward the coast.

These arborescent crotons were of two new species,* very remarkable for their form, and peculiar to the peninsula of Araya.

(* Croton argyrophyllus and C. marginatus.

) We arrived too late at the Laguna Chica to visit another rock situated farther east and celebrated by the name of the Laguna Grande, or the Laguna del Obispo.

* (* Great Lake, or the Bishop's Lake.

) We contented ourselves with admiring it from the height of the mountains that command the view; and, excepting the ports of Ferrol and Acapulco, there is perhaps none presenting a more extraordinary configuration.

It is an inland gulf two miles and a half long from east to west, and one mile broad.

The rocks of mica-slate that form the entrance of the port leave a free passage only two hundred and fifty toises broad.

The water is everywhere from fifteen to twenty-five fathoms deep.

Probably the government of Cumana will one day take advantage of the possession of this inland gulf and of that of Mochima,* eight leagues east of the bad road of Nueva Barcelona.

(* This is a long narrow gulf, three miles from north to south, similar to the fiords of Norway.

) The family of M. Navarete were waiting for us with impatience on the beach; and, though our boat carried a large sail, we did not arrive at Maniquarez before night.

We prolonged our stay at Cumana only a fortnight.

Having lost all hope of the arrival of a packet from Corunna, we availed ourselves of an American vessel, laden at Nueva Barcelona with salt provision for the island of Cuba.

We had now passed sixteen months on this coast and in the interior of Venezuela, and on the 16th of November we parted from our friends at Cumana to make the passage for the third time across the gulf of Cariaco to Nueva Barcelona.

The night was cool and delicious.

It was not without emotion that we beheld for the last time the disc of the moon illuminating the summit of the cocoa-trees that surround the banks of the Manzanares.

The breeze was strong and in less than six hours we anchored near the Morro of Nueva Barcelona, where the vessel which was to take us to the Havannah was ready to sail.