We arrived on the 15th of July at the Fundacion, or Villa, del Pao, founded in 1744, and situated very favourably for a commercial station between Nueva Barcelona and Angostura. Its real name is El Concepcion del Pao. Alcedo, La Cruz, Olmedilla, and many other geographers, have mistaken the situation of this small town of the Llanos of Barcelona, confounding it either with San Juan Bauptisto del Pao of the Llanos of Caracas, or with El Valle del Pao de Zarate. Though the weather was cloudy I succeeded in obtaining some heights of alpha Centauri, serving to determine the lat.i.tude of the place; which is 8 degrees 37 minutes 57 seconds. Some alt.i.tudes of the sun gave me 67 degrees 8 minutes 12 seconds for the longitude, supposing Angostura to be 66 degrees 15 minutes 21 seconds. The astronomical determinations of Calabozo and Concepcion del Pao are very important to the geography of this country, where, in the midst of savannahs, fixed points are altogether wanting. Some fruit-trees grow in the vicinity of Pao: they are rarely seen in the Llanos. We even found some cocoa-trees, which appeared very vigorous, notwithstanding the great distance of the sea.
I was the more struck with this fact because doubts have recently been started respecting the veracity of travellers, who a.s.sert that they have seen the cocoa-tree, which is a palm of the sh.o.r.e, at Timbuctoo, in the centre of Africa. We several times saw cocoa-trees amid the cultivated spots on the banks of the Rio Magdalena, more than a hundred leagues from the coast.
Five days, which to us appeared very tedious, brought us from Villa del Pao to the port of Nueva Barcelona. As we advanced the sky became more serene, the soil more dusty, and the atmosphere more hot. The heat from which we suffered is not entirely owing to the temperature of the air, but is produced by the fine sand mingled with it; this sand strikes against the face of the traveller, as it does against the ball of the thermometer. I never observed the mercury rise in America, amid a wind of sand, above 45.8 degrees centigrade. Captain Lyon, with whom I had the pleasure of conversing on his return from Mourzouk, appeared to me also inclined to think that the temperature of fifty-two degrees, so often felt in Fezzan, is produced in great part by the grains of quartz suspended in the atmosphere. Between Pao and the village of Santa Cruz de Cachipo, founded in 1749, and inhabited by five hundred Caribs, we pa.s.sed the western elongation of the little table-land, known by the name of Mesa de Amana. This table-land forms a point of part.i.tion between the Orinoco, the Guarapiche, and the coast of New Andalusia. Its height is so inconsiderable that it would scarcely be an obstacle to the establishment of inland navigation in this part of the Llanos. The Rio Mano however, which flows into the Orinoco above the confluence of the Carony, and which D"Anville (I know not on what authority) has marked in the first edition of his great map as issuing from the lake of Valencia, and receiving the waters of the Guayra, could never have served as a natural ca.n.a.l between two basins of rivers. No bifurcation of this kind exists in the Llano. A great number of Carib Indians, who now inhabit the missions of Piritu, were formerly on the north and east of the table-land of Amana, between Maturin, the mouth of the Rio Arco, and the Guarapiche. The incursions of Don Joseph Careno, one of the most enterprising governors of the province of c.u.mana, occasioned a general migration of independent Caribs toward the banks of the Lower Orinoco in 1720.
The whole of this vast plain consists of secondary formations which to the southward rest immediately on the granitic mountains of the Orinoco. On the north-west they are separated by a narrow band of transition-rocks from the primitive mountains of the sh.o.r.e of Caracas.
This abundance of secondary rocks, covering without interruption a s.p.a.ce of more than seven thousand square leagues,* is a phenomenon the more remarkable in that region of the globe, because in the whole of the Sierra da la Parima, between the right bank of the Orinoco and the Rio Negro, there is, as in Scandinavia, a total absence of secondary formations. (* Reckoning only that part of the Llanos which is bounded by the Rio Apure on the south, and by the Sierra Nevada de Merida and the Parima de las Rosas on the west.) The red sandstone, containing some vestiges of fossil wood (of the family of monocotyledons) is seen everywhere in the plains of Calabozo: farther east it is overlaid by calcareous and gypseous rocks which conceal it from the research of the geologist. The marly gypsum, of which we collected specimens near the Carib mission of Cachipo, appeared to me to belong to the same formation as the gypsum of Ortiz. To cla.s.s it according to the type of European formations I would range it among the gypsums, often muriatiferous, that cover the Alpine limestone or zechstein. Farther north, in the direction of the mission of San Josef de Curataquiche, M. Bonpland picked up in the plain some fine pieces of riband jasper, or Egyptian pebbles. We did not see them in their native place enchased in the rock, and cannot determine whether they belong to a very recent conglomerate or to that limestone which we saw at the Morro of Nueva Barcelona, and which is not transition limestone though it contains beds of schistose jasper (kieselschiefer).
We rested on the night of the 16th of July in the Indian village of Santa Cruz de Cachipo. This mission, founded in 1749 by several Carib families who inhabited the inundated and unhealthy banks of the Lagunetas de Auache, is opposite the confluence of the Zir Puruay with the Orinoco. We lodged at the house of the missionary, Fray Jose de las Piedras; and, on examining the registers of the parish, we saw how rapidly the prosperity of the community has been advanced by his zeal and intelligence. Since we had reached the middle of the plains, the heat had increased to such a degree that we should have preferred travelling no more during the day; but we were without arms and the Llanos were then infested by large numbers of robbers who attacked and murdered the whites who fell into their hands. Nothing can be worse than the administration of justice in these colonies. We everywhere found the prisons filled with malefactors on whom sentence is not pa.s.sed till after the lapse of seven or eight years. Nearly a third of the prisoners succeed in making their escape; and the unpeopled plains, filled with herds, furnish them with booty. They commit their depredations on horseback in the manner of the Bedouins. The insalubrity of the prisons would be attended with fatal results but that these receptacles are cleared from time to time by the flight of the prisoners. It also frequently happens that sentences of death, tardily p.r.o.nounced by the Audiencia of Caracas, cannot be executed for want of a hangman. In these cases the barbarous custom is observed of pardoning one criminal on condition of his hanging the others. Our guides related to us that, a short time before our arrival on the coast of c.u.mana, a Zambo, known for the great ferocity of his manners, determined to screen himself from punishment by turning executioner.
The preparations for the execution however, shook his resolution; he felt a horror of himself, and preferring death to the disgrace of thus saving his life, he called again for his irons which had been struck off. He did not long remain in prison, and he underwent his sentence through the baseness of one of his accomplices. This awakening of a sentiment of honour in the soul of a murderer is a psychologic phenomenon worthy of reflection. The man who had so often shed the blood of travellers in the plains recoiled at the idea of becoming the pa.s.sive instrument of justice in inflicting upon others a punishment which he felt that he himself deserved.
If, even in the peaceful times when M. Bonpland and myself had the good fortune to travel through North and South America, the Llanos were the refuge of malefactors who had committed crimes in the missions of the Orinoco, or who had escaped from the prisons on the coast, how much worse must that state of things have been rendered by discord during the continuance of that sanguinary struggle which has terminated in conferring freedom and independence on those vast regions! Our European wastes and heaths are but a feeble image of the savannahs of the New Continent which for the s.p.a.ce of eight or ten thousand square leagues are smooth as the surface of the sea. The immensity of their extent insures impunity to robbers, who conceal themselves more effectually in the savannahs than in our mountains and forests; and it is easy to conceive that even a European police would not be very effective in regions where there are travellers and no roads, herds and no herdsmen, and farms so solitary that notwithstanding the powerful action of the mirage, a journey of several days may be made without seeing one appear within the horizon.
Whilst traversing the Llanos of Caracas, New Barcelona, and c.u.mana, which succeed each other from west to east, from the snowy mountains of Merida to the Delta of the Orinoco, we feel anxious to know whether these vast tracts of land are destined by nature to serve eternally for pasture or whether they will at some future time be subject to the plough and the spade. This question is the more important as the Llanos, situated at the two extremities of South America, are obstacles to the political union of the provinces they separate. They prevent the agriculture of the coast of Venezuela from extending towards Guiana and they impede that of Potosi from advancing in the direction of the mouth of the Rio de la Plata. The intermediate Llanos preserve, together with pastoral life, somewhat of a rude and wild character which separates and keeps them remote from the civilization of countries anciently cultivated. Thus it has happened that in the war of independence they have been the scene of struggle between the hostile parties; and that the inhabitants of Calabozo have almost seen the fate of the confederate provinces of Venezuela and Cundinamarca decided before their walls. In a.s.signing limits to the new states and to their subdivisions, it is to be hoped there may not be cause hereafter to repent having lost sight of the importance of the Llanos, and the influence they may have on the disunion of communities which important common interests should bring together. These plains would serve as natural boundaries like the seas or the virgin forests of the tropics, were it not that armies can cross them with greater facility, as their innumerable troops of horses and mules and herds of oxen furnish every means of conveyance and subsistence.
What we have seen of the power of man struggling against the force of nature in Gaul, in Germany and recently (but still beyond the tropics) in the United States, scarcely affords any just measure of what we may expect from the progress of civilization in the torrid zone. Forests disappear but very slowly by fire and the axe when the trunks of trees are from eight to ten feet in diameter; when in falling they rest one upon another, and the wood, moistened by almost continual rains, is excessively hard. The planters who inhabit the Llanos or Pampas do not generally admit the possibility of subjecting the soil to cultivation; it is a problem not yet solved. Most of the savannahs of Venezuela have not the same advantage as those of North America. The latter are traversed longitudinally by three great rivers, the Missouri, the Arkansas, and the Red River of Nachitoches; the savannahs of Araura, Calabozo, and Pao are crossed in a transverse direction only by the tributary streams of the Orinoco, the most westerly of which (the Cari, the Pao, the Acaru, and the Manapire) have very little water in the season of drought. These streams scarcely flow at all toward the north; so that in the centre of the Llanos there remain vast tracts of land called bancos and mesas* frightfully parched. (* The Spanish words banco and mesa signify literally bench and table. In the Llanos of South America little elevations rising slightly above the general elevation of the plain are called bancos and mesas from their supposed resemblance to benches and tables.) The eastern parts, fertilized by the Portuguesa, the Masparro, and the Orivante, and by the tributary streams of those three rivers, are most susceptible of cultivation.
The soil is sand mixed with clay, covering a bed of quartz pebbles.
The vegetable mould, the princ.i.p.al source of the nutrition of plants, is everywhere extremely thin. It is scarcely augmented by the fall of the leaves, which, in the forests of the torrid zone, is less periodically regular than in temperate climates. During thousands of years the Llanos have been dest.i.tute of trees and brushwood; a few scattered palms in the savannah add little to that hydruret of carbon, that extractive matter, which, according to the experiments of Saussure, Davy, and Braconnot, gives fertility to the soil. The social plants which almost exclusively predominate in the steppes, are monocotyledons; and it is known how much gra.s.ses impoverish the soil into which their fibrous roots penetrate. This action of the killingias, paspalums and cenchri, which form the turf, is everywhere the same; but where the rock is ready to pierce the earth this varies according as it rests on red sandstone, or on compact limestone and gypsum; it varies according as periodical inundations acc.u.mulate mud on the lower grounds or as the shock of the waters carries away from the small elevations the little soil that has covered them. Many solitary cultivated spots already exist in the midst of the pastures where running water and tufts of the mauritia palm have been found.
These farms, sown with maize, and planted with ca.s.sava, will multiply considerably if trees and shrubs be augmented.
The aridity and excessive heat of the mesas do not depend solely on the nature of their surface and the local reverberation of the soil; their climate is modified by the adjacent regions; by the whole of the Llano of which they form a part. In the deserts of Africa or Arabia, in the Llanos of South America, in the vast heaths extending from the extremity of Jutland to the mouth of the Scheldt, the stability of the limits of the desert, the savannahs, and the downs, depends chiefly on their immense extent and the nakedness these plains have acquired from some revolution destructive of the ancient vegetation of our planet.
By their extent, their continuity, and their ma.s.s they oppose the inroads of cultivation and preserve, like inland gulfs, the stability of their boundaries. I will not enter upon the great question, whether in the Sahara, that Mediterranean of moving sands, the germs of organic life are increased in our days. In proportion as our geographical knowledge has extended we have discovered in the eastern part of the desert islets of verdure; oases covered with date-trees crowd together in more numerous archipelagos, and open their ports to the caravans; but we are ignorant whether the form of the oases have not remained constantly the same since the time of Herodotus. Our annals are too incomplete to enable us to follow Nature in her slow and gradual progress. From these s.p.a.ces entirely bare whence some violent catastrophe has swept away the vegetable covering and the mould; from those deserts of Syria and Africa which, by their petrified wood, attest the changes they have undergone; let us turn to the gra.s.s-covered Llanos and to the consideration of phenomena that come nearer the circle of our daily observations. Respecting the possibility of a more general cultivation of the steppes of America, the colonists settled there, concur in the opinions I have deduced from the climatic action of these steppes considered as surfaces, or continuous ma.s.ses. They have observed that downs enclosed within cultivated and wooded land sooner yield to the labours of the husbandman than soils alike circ.u.mscribed, but forming part of a vast surface of the same nature. This observation is extremely just whether in reference to soil covered with heath, as in the north of Europe; with cistuses, mastic-trees, or palmettos, as in Spain; or with cactuses, argemones, or brathys, as in equinoctial America. The more s.p.a.ce the a.s.sociation occupies the more resistance do the social plants oppose to the labourer. With this general cause others are combined in the Llanos of Venezuela; namely the action of the small gra.s.ses which impoverish the soil; the total absence of trees and brushwood; the sandy winds, the heat of which is increased by contact with a surface absorbing the rays of the sun during twelve hours, and unshaded except by the stalks of the aristides, chanchuses, and paspalums. The progress observable on the vegetation of large trees and the cultivation of dicotyledonous plants in the vicinity of towns, (for instance around Calabozo and Pao) prove what may be gained upon the Llano by attacking it in small portions, enclosing it by degrees, and dividing it by coppices and ca.n.a.ls of irrigation. Possibly the influence of the winds which render the soil sterile might be diminished by sowing on a large scale, for example, over fifteen or twenty acres, the seeds of the psidium, the croton, the ca.s.sia, or the tamarind, which prefer dry, open spots. I am far from believing that the savannahs will ever disappear entirely; or that the Llanos, so useful for pasturage and the trade in cattle, will ever be cultivated like the valleys of Aragua or other parts near the coast of Caracas and c.u.mana: but I am persuaded that in the lapse of ages a considerable portion of these plains, under a government favourable to industry, will lose the wild aspect which has characterized them since the first conquest by Europeans.
After three days" journey we began to perceive the chain of the mountains of c.u.mana, which separates the Llanos, or, as they are often called here, the great sea of verdure,* from the coast of the Caribbean Sea. (* Los Llanos son como un mar de yerbas--The Llanos are like a vast sea of gra.s.s--is an observation often repeated in these regions.) If the Bergantin be more than eight hundred toises high, it may be seen supposing only an ordinary refraction of one fourteenth of the arch, at the distance of twenty-seven nautical leagues; but the state of the atmosphere long concealed from us the majestic view of this curtain of mountains. It appeared at first like a fog-bank which hid the stars near the pole at their rising and setting; gradually this body of vapour seemed to augment and condense, to a.s.sume a bluish tint, and become bounded by sinuous and fixed outlines. The same effects which the mariner observes on approaching a new land present themselves to the traveller on the borders of the Llano. The horizon began to enlarge in some part and the vault of heaven seemed no longer to rest at an equal distance on the gra.s.s-covered soil. A llanero, or inhabitant of the Llanos, is happy only when, as expressed in the simple phraseology of the country, he can see everywhere well around him. What appears to European eyes a covered country, slightly undulated by a few scattered hills, is to him a rugged region bristled with mountains. After having pa.s.sed several months in the thick forests of the Orinoco, in places where one is accustomed, when at any distance from the river, to see the stars only in the zenith, as through the mouth of a well, a journey in the Llanos is peculiarly agreeable and attractive. The traveller experiences new sensations; and, like the Llanero, he enjoys the happiness of seeing well around him. But this enjoyment, as we ourselves experienced, is not of long duration. There is doubtless something solemn and imposing in the aspect of a boundless horizon, whether viewed from the summits of the Andes or the highest Alps, amid the expanse of the ocean or in the vast plains of Venezuela and Tuc.u.man. Infinity of s.p.a.ce, as poets in every language say, is reflected within ourselves; it is a.s.sociated with ideas of a superior order; it elevates the mind which delights in the calm of solitary meditation. It is true, also, that every view of unbounded s.p.a.ce bears a peculiar character. The prospect surveyed from a solitary peak varies according as the clouds reposing on the plain extend in layers, are conglomerated in groups, or present to the astonished eye, through broad openings, the habitations of man, the labour of agriculture, or the verdant tint of the aerial ocean. An immense sheet of water, animated by a thousand various beings even to its utmost depths, changing perpetually in colour and aspect, moveable at its surface like the element that agitates it, all charm the imagination during long voyages by sea; but the dusty and creviced Llano, throughout a great part of the year, has a depressing influence on the mind by its unchanging monotony. When, after eight or ten days"
journey, the traveller becomes accustomed to the mirage and the brilliant verdure of a few tufts of mauritia* (* The fan-palm, or sago-tree of Guiana.) scattered from league to league, he feels the want of more varied impressions. He loves again to behold the great tropical trees, the wild rush of torrents or hills and valleys cultivated by the hand of the labourer. If the deserts of Africa and of the Llanos or savannahs of the New Continent filled a still greater s.p.a.ce than they actually occupy, nature would be deprived of many of the beautiful products peculiar to the torrid zone.* (* In calculating from maps on a very large scale I found the Llanos of c.u.mana, Barcelona, and Caracas, from the delta of the Orinoco to the northern bank of the Apure, 7200 square leagues; the Llanos between the Apure and Putumayo, 21,000 leagues; the Pampas on the north-west of Buenos Ayres, 40,000 square leagues; the Pampas south of the parallel of Buenos Ayres, 37,000 square leagues. The total area of the Llanos of South America, covered with gramina, is consequently 105,200 square leagues, twenty leagues to an equatorial degree.) The heaths of the north, the steppes of the Volga and the Don, are scarcely poorer in species of plants and animals than are the twenty-eight thousand square leagues of savannahs extending in a semicircle from north-east to south-west, from the mouths of the Orinoco to the banks of the Caqueta and the Putumayo, beneath the finest sky in the world, and in the land of plantains and bread-fruit trees. The influence of the equinoctial climate, everywhere else so vivifying, is not felt in places where the great a.s.sociations of gramina almost exclude every other plant. Judging from the aspect of the soil we might have believed ourselves to be in the temperate zone and even still farther northward but that a few scattered palms, and at nightfall the fine constellations of the southern sky (the Centaur, Canopus, and the innumerable nebulae with which the Ship is resplendent), reminded us that we were only eight degrees distant from the equator.
A phenomenon which fixed the attention of De Luc and which in these latter years has furnished a subject of speculation to geologists, occupied us much during our journey across the Llanos. I allude not to those blocks of primitive rock which occur, as in the Jura, on the slope of limestone mountains, but to those enormous blocks of granite and syenite which, in limits very distinctly marked by nature, are found scattered on the north of Holland, Germany and the countries of the Baltic. It seems to be now proved that, distributed as in radii, they came at the time of the ancient revolutions of our globe from the Scandinavian peninsula southward; and that they did not primitively belong to the granitic chains of the Harz and Erzgeberg, which they approach without, however, reaching their foot.* (* Leopold von Buch, Voyage en Norwege volume 1 page 30.) I was surprised at not seeing one of these blocks in the Llanos of Venezuela, though these immense plains are bounded on the south by the Sierra Parima, a group of mountains entirely granitic and exhibiting in its denticulated and often columnar peaks traces of the most violent destruction. Northward the granitic chain of the Silla de Caracas and Porto Cabello are separated from the Llanos by a screen of mountains that are schistose between Villa de Cura and Parapara, and calcareous between the Bergantin and Caripe. I was no less struck by this absence of blocks on the banks of the Amazon. La Condamine affirms that from the Pongo de Manseriche to the Strait of Pauxis not the smallest stone is to be found. Now the basin of the Rio Negro and of the Amazon is also a Llano, a plain like those of Venezuela and Buenos Ayres. The difference consists only in the state of vegetation. The two Llanos situated at the northern and southern extremities of South America are covered with gramina; they are treeless savannahs; but the intermediate Llano, that of the Amazon, exposed to almost continual equatorial rains, is a thick forest. I do not remember having heard that the Pampas of Buenos Ayres or the savannahs of the Missouri* and New Mexico contain granitic blocks. (* Are there any isolated blocks in North America northward of the great lakes?) The absence of this phenomenon appears general in the New World as it probably also is in Sahara, in Africa; for we must not confound the rocky ma.s.ses that pierce the soil in the midst of the desert, and of which travellers often make mention, with mere scattered fragments. These facts seem to prove that the blocks of Scandinavian granite which cover the sandy countries on the south of the Baltic, and those of Westphalia and Holland, must be traced to some local revolution. The ancient conglomerate (red sandstone) which covers a great part of the Llanos of Venezuela and of the basin of the Amazon contains no doubt fragments of the same primitive rocks which const.i.tute the neighbouring mountains; but the convulsions of which these mountains exhibit evident marks, do not appear to have been attended with circ.u.mstances favourable to the removal of great blocks. This geognostic phenomenon was to me the more unexpected since there exists nowhere in the world so smooth a plain entirely granitic. Before my departure from Europe I had observed with surprise that there were no primitive blocks in Lombardy and in the great plain of Bavaria which appears to be the bottom of an ancient lake, and which is situated two hundred and fifty toises above the level of the ocean. It is bounded on the north by the granites of the Upper Palatinate; and on the south by Alpine limestone, transition-thonschiefer, and the mica-slates of the Tyrol.
We arrived, on the 23rd of July, at the town of Nueva Barcelona, less fatigued by the heat of the Llanos, to which we had been long accustomed, than annoyed by the winds of sand which occasion painful chaps in the skin. Seven months previously, in going from c.u.mana to Caracas, we had rested a few hours at the Morro de Barcelona, a fortified rock, which, near the village of Pozuelos, is joined to the continent only by a neck of land. We were received with the kindest hospitality in the house of Don Pedro Lavie, a wealthy merchant of French extraction. This gentleman, who was accused of having given refuge to the unfortunate Espana when a fugitive on these coasts in 1796, was arrested by order of the Audiencia, and conveyed as a prisoner to Caracas. The friendship of the governor of c.u.mana and the remembrance of the services he had rendered to the rising commerce of those countries contributed to procure his liberty. We had endeavoured to alleviate his captivity by visiting him in prison; and we had now the satisfaction of finding him in the midst of his family. Illness under which he was suffering had been aggravated by confinement; and he sank into the grave without seeing the dawn of those days of independence, which his friend Don Joseph Espana had predicted on the scaffold prior to his execution. "I die," said that man, who was formed for the accomplishment of grand projects, "I die an ignominious death; but my fellow citizens will soon piously collect my ashes, and my name will reappear with glory." These remarkable words were uttered in the public square of Caracas, on the 8th of May, 1799.
In 1790 Nueva Barcelona contained scarcely ten thousand inhabitants, and in 1800, its population was more than sixteen thousand. The town was founded in 1637 by a Catalonian conquistador, named Juan Urpin. A fruitless attempt was then made, to give the whole province the name of New Catalonia. As our maps often mark two towns, Barcelona and c.u.managoto, instead of one, and as the two names are considered as synonymous, it may be well to explain the cause of this error.
Anciently, at the mouth of the Rio Neveri, there was an Indian town, built in 1588 by Lucas Faxardo, and named San Cristoval de los c.u.managotos. This town was peopled solely by natives who came from the saltworks of Apaicuare. In 1637 Urpin founded, two leagues farther inland, the Spanish town of Nueva Barcelona, which he peopled with some of the inhabitants of c.u.managoto, together with some Catalonians.
For thirty-four years, disputes were incessantly arising between the two neighbouring communities till in 1671, the governor Angulo succeeded in persuading them to establish themselves on a third spot, where the town of Barcelona now stands. According to my observations it is situated in lat.i.tude 10 degrees 6 minutes 52 seconds.* (* These observations were made on the Plaza Major. They are merely the result of six circ.u.m-meridian heights of Canopus, taken all in one night. In Las Memorias de Espinosa the lat.i.tude is stated to be 10 degrees 9 minutes 6 seconds. The result of M. Ferrer"s observations made it 10 degrees 8 minutes 24 seconds.) The ancient town of c.u.managoto is celebrated in the country for a miraculous image of the Virgin,* which the Indians say was found in the hollow trunk of an old tutumo, or calabash-tree (Crescentia cujete). (* La milagrosa imagen de Maria Santissima del Socorro, also called La Virgen del Tutumo.) This image was carried in procession to Nueva Barcelona; but whenever the clergy were dissatisfied with the inhabitants of the new city, the Virgin fled at night, and returned to the trunk of the tree at the mouth of the river. This miracle did not cease till a fine convent (the college of the Propaganda) was built, to receive the Franciscans. In a similar case, the Bishop of Caracas caused the image of Our Lady de los Valencianos to be placed in the archives of the bishopric, where she remained thirty years under seal.
The climate of Barcelona is not so hot as that of c.u.mana but it is extremely damp and somewhat unhealthy in the rainy season. M. Bonpland had borne very well the irksome journey across the Llanos; and had recovered his strength and activity. With respect to myself, I suffered more at Barcelona than I did at Angostura, immediately after our pa.s.sage on the rivers. One of those extraordinary tropical rains during which, at sunset, drops of enormous size fall at great distances from one another, caused me to experience sensations which seemed to threaten an attack of typhus, a disease then prevalent on that coast. We remained nearly a month at Barcelona where we found our friend Fray Juan Gonzales, of whom I have often spoken, and who had traversed the Upper Orinoco before us. He expressed regret that we had not been able to prolong our visit to that unknown country; and he examined our plants and animals with that interest which must be felt by even the most uninformed man for the productions of a region he has long since visited. Fray Juan had resolved to go to Europe and to accompany us as far as the island of Cuba. We were together for the s.p.a.ce of seven months, and his society was most agreeable: he was cheerful, intelligent and obliging. How little did we antic.i.p.ate the sad fate that awaited him. He took charge of a part of our collections; and a friend of his own confided to his care a child who was to be conveyed to Spain for its education. Alas! the collection, the child and the young ecclesiastic were all buried in the waves.
South-east of Nueva Barcelona, at the distance of two Leagues, there rises a lofty chain of mountains, ab.u.t.ting on the Cerro del Bergantin, which is visible at c.u.mana. This spot is known by the name of the hot waters, (aguas calientes). When I felt my health sufficiently restored, we made an excursion thither on a cool and misty morning.
The waters, which are loaded with sulphuretted hydrogen, issue from a quartzose sandstone, lying on compact limestone, the same as that we had examined at the Morro. We again found in this limestone intercalated beds of black hornstein, pa.s.sing into kieselschiefer. It is not, however, a transition rock; by its position, its division into small strata, its whiteness and its dull and conchoidal fractures (with very flattened cavities), it rather approximates to the limestone of Jura. The real kieselschiefer and Lydian-stone have not been observed hitherto except in the transition-slates and limestones.
Is the sandstone whence the springs of the Bergantin issue of the same formation as the sandstone of the Imposible and the Tumiriquiri? The temperature of the thermal waters is only 43.2 degrees centigrade (the atmosphere being 27). They flow first to the distance of forty toises over the rocky surface of the ground; then they rush down into a natural cavern; and finally they pierce through the limestone to issue out at the foot of the mountain on the left bank of the little river Narigual. The springs, while in contact with the oxygen of the atmosphere, deposit a good deal of sulphur. I did not collect, as I had done at Mariara, the bubbles of air that rise in jets from these thermal waters. They no doubt contain a large quant.i.ty of nitrogen because the sulphuretted hydrogen decomposes the mixture of oxygen and nitrogen dissolved in the spring. The sulphurous waters of San Juan which issue from calcareous rock, like those of the Bergantin, have also a low temperature (31.3 degrees); while in the same region the temperature of the sulphurous waters of Mariara and Las Trincheras (near Porto Cabello), which gush immediately from gneiss-granite, is 58.9 degrees the former, and 90.4 degrees the latter. It would seem as if the heat which these springs acquire in the interior of the globe diminishes in proportion as they pa.s.s from primitive to secondary superposed rocks.
Our excursion to the Aguas Calientes of Bergantin ended with a vexatious accident. Our host had lent us one of his finest saddle-horses. We were warned at the same time not to ford the little river of Narigual. We pa.s.sed over a sort of bridge, or rather some trunks of trees laid closely together, and we made our horses swim, holding their bridles. The horse I had ridden suddenly disappeared after struggling for some time under water: all our endeavours to discover the cause of this accident were fruitless. Our guides conjectured that the animal"s legs had been seized by the caymans which are very numerous in those parts. My perplexity was extreme: delicacy and the affluent circ.u.mstances of my host forbade me to think of repairing his loss; and M. Lavie, more considerate of our situation than sensible of his own misfortune, endeavoured to tranquillize us by exaggerating the facility with which fine horses were procurable from the neighbouring savannahs.
The crocodiles of the Rio Neveri are large and numerous, especially near the mouth of the river; but in general they are less fierce than the crocodiles of the Orinoco. These animals manifest in America the same contrasts of ferocity as in Egypt and Nubia: this fact is obvious when we compare with attention the narratives of Burckhardt and Belzoni. The state of cultivation in different countries and the amount of population in the proximity of rivers modify the habits of these large saurians: they are timid when on dry ground and they flee from man, even in the water, when they are not in want of food and when they perceive any danger in attacking. The Indians of Nueva Barcelona convey wood to market in a singular manner. Large logs of zygophyllum and caesalpinia* are thrown into the river and carried down by the stream, while the owners of the wood swim here and there to float the pieces that are stopped by the windings of the banks. (*
The Lecythis ollaria, in the vicinity of Nueva Barcelona, furnishes excellent timber. We saw trunks of this tree seventy feet high. Around the town, beyond that arid zone of cactus which separates Nueva Barcelona from the steppe, grow the Clerodendrum tenuifolium, the Ionidium itubu, which resembles the Viola, and the Allionia violacea.) This could not be done in the greater part of those American rivers in which crocodiles are found. The town of Barcelona has not, like c.u.mana, an Indian suburb; and the only natives who are seen there are inhabitants of the neighbouring missions or of huts scattered in the plain. Neither the one nor the other are of Carib race, but a mixture of the c.u.managotos, Palenkas and Piritus; short, stunted, indolent and addicted to drinking. Fermented ca.s.sava is here the favourite beverage; the wine of the palm-tree, which is used on the Orinoco, being almost unknown on the coast. It is curious to observe that men in different zones, to satisfy the pa.s.sion of inebriety, employ not only all the families of monocotyledonous and dicotyledonous plants, but even the poisonous Agaric (Amanita muscaria) of which, with disgusting economy, the Coriacs have learnt to drink the same juice several times during five successive days.* (* Mr. Langsdor (Wetterauisches Journal part 1 page 254) first made known this very extraordinary physiological phenomenon, which I prefer describing in Latin: Coriaecorum gens, in ora Asiae septentrioni opposita, potum sibi excogitavit ex succo inebriante agarici muscarii. Qui succus (aeque ut asparagorum), vel per humanum corpus transfusus, temulentiam nihilominus facit. Quare gens misera et inops, quo rarius mentis sit suae, propriam urinam bibit identidem: continuoque mingens rursusque hauriens eundem succ.u.m (dicas, ne ulla in parte mundi desit ebrietas), pauculis agaricis producere in diem quintum temulentiam potest.)
The packet boats (correos) from Corunna bound for the Havannah and Mexico had been due three months; and it was believed they had been taken by the English cruisers stationed on this coast. Anxious to reach c.u.mana, in order to avail ourselves of the first opportunity that might offer for our pa.s.sage to Vera Cruz, we hired an open boat called a lancha, a sort of craft employed habitually in the lat.i.tudes east of Cape Codera where the sea is scarcely ever rough. Our lancha, which was laden with cacao, carried on a contraband trade with the island of Trinidad. For this reason the owner imagined we had nothing to fear from the enemy"s vessels, which then blockaded all the Spanish ports. We embarked our collection of plants, our instruments and our monkeys; and, the weather being delightful, we hoped to make a very short pa.s.sage from the mouth of the Rio Neveri to c.u.mana: but we had scarcely reached the narrow channel between the continent and the rocky isles of Borracha and the Chimanas, when to our great surprise we came in sight of an armed boat, which, whilst hailing us from a great distance, fired some musket-shot at us. The boat belonged to a privateer of Halifax; and I recognized among the sailors a Prussian, a native of Memel. I had found no opportunity, since my arrival in America, of expressing myself in my native language, and I could have wished to have spoken it on a less unpleasant occasion. Our protestations were without effect: we were carried on board the privateer, and the captain, affecting not to recognize the pa.s.sports delivered by the governor of Trinidad for the illicit trade, declared us to be a lawful prize. Being a little in the habit of speaking English, I entered into conversation with the captain, begging not to be taken to Nova Scotia, but to be put on sh.o.r.e on the neighbouring coast. While I endeavoured, in the cabin, to defend my own rights and those of the owner of the lancha, I heard a noise on deck. Something was whispered to the captain, who left us in consternation. Happily for us, an English sloop of war, the Hawk, was cruising in those parts, and had signalled the captain to bring to; but the signal not being promptly answered, a gun was fired from the sloop and a midshipman sent on board our vessel. He was a polite young man, and gave me hopes that the lancha, which was laden with cacao, would be given up, and that on the following day we might pursue our voyage. In the meantime he invited me to accompany him on board the sloop, a.s.suring me that his commander, Captain Garnier, would furnish me with better accommodation for the night than I should find in the vessel from Halifax.
I accepted these obliging offers and was received with the utmost kindness by Captain Garnier, who had made the voyage to the north-west coast of America with Vancouver, and who appeared to be highly interested in all I related to him respecting the great cataracts of Atures and Maypures, the bifurcation of the Orinoco and its communication with the Amazon. He introduced to me several of his officers who had been with Lord Macartney in China. I had not, during the s.p.a.ce of a year, enjoyed the society of so many well-informed persons. They had learned from the English newspapers the object of my enterprise. I was treated with great confidence and the commander gave me up his own state-room. They gave me at parting the astronomical Ephemerides for those years which I had not been able to procure in France or Spain. I am indebted to Captain Garnier for the observations I was enabled to make on the satellites beyond the equator and I feel it a duty to record here the grat.i.tude I feel for his kindness. Coming from the forests of Ca.s.siquiare, and having been confined during whole months to the narrow circle of missionary life, we felt a high gratification at meeting for the first time with men who had sailed round the world, and whose ideas were enlarged by so extensive and varied a course. I quitted the English vessel with impressions which are not yet effaced from my remembrance, and which rendered me more than ever satisfied with the career on which I had entered.
We continued our pa.s.sage 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 hara.s.sed the pelicans in order to seize their prey, indicated our approach to the coast of c.u.mana. 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 c.u.mana. 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 sh.o.r.e, 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 c.u.mana 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 c.u.mana 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 c.u.mana, 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 c.u.mana. 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 c.u.mana. 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 pa.s.sed 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 c.u.mana.* (* 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 quant.i.ties 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 ma.s.ses 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 pa.s.sing 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 c.u.mana. 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 s.p.a.ce 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 pa.s.sed 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 pa.s.s by portage over the neck of land or northern d.y.k.e. Though the waters on these sh.o.r.es 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 c.u.mana, is filled with fossil sh.e.l.ls 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 c.u.mana, Guayra or Curacao. It would be curious to discover whether any of these sh.e.l.ls 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 phosph.o.r.escence of the ocean and the sports of the porpoises which surrounded our canoe somewhat atoned for this disappointment. We again pa.s.sed 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 c.u.mana. 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 princ.i.p.al 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 c.u.mana. The vegetable earth in this country is only thirty toises above sea level. Sometimes there is no rain for the s.p.a.ce 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 c.u.mana and Araya contains nearly nine-tenths of the quant.i.ty 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 gra.s.s 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 cla.s.s of the people. We wandered for eight or nine hours among rocks totally bare of vegetation. The mica-slate pa.s.ses 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 t.i.tanite. 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 ma.s.ses 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 c.u.mana. 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 gla.s.sy l.u.s.tre 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 const.i.tute here but one formation. The presence of cyanite, rutile-t.i.tanite, 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 a.s.serted 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 ma.s.s 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 c.u.mana 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 c.u.manacoa? 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 quant.i.ties 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 const.i.tutes 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 const.i.tutes 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 ma.s.ses of native alum, to yield which the rocks must be roasted. I know not of any deposits a.n.a.logous to those I brought from c.u.mana; for the capillary and fibrous ma.s.ses 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 dest.i.tute 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 alumif