In the island of Teneriffe, strata of tufa, puzzolana, and clay, separate the range of basaltic hills from the currents of recent lithoid lava, and from the eruptions of the present volcano. In the same manner as the eruptions of Epomeo in the island of Ischia, and those of Jorullo in Mexico, have taken place in countries covered with trappean porphyry, ancient basalt, and volcanic ashes, so the peak of Teyde has raised itself amidst the wrecks of submarine volcanoes. Notwithstanding the difference of composition in the recent lavas of the Peak, there is a certain regularity of position, which must strike the naturalist least skilled in geognosy. The great elevated plain of Retama separates the black, basaltic, and earthlike lava, from the vitreous and feldsparry lava, the basis of which is obsidian, pitch-stone, and phonolite. This phenomenon is the more remarkable, inasmuch as in Bohemia and in other parts of Europe, the porphyrschiefer with base of phonolite* (* Klingstein. Werner.) covers also the convex summits of basaltic mountains.
It has already been observed, that from the level of the sea to Portillo, and as far as the entrance on the elevated plain of the Retama, that is, two-thirds of the total height of the volcano, the ground is so covered with plants, that it is difficult to make geological observations. The currents of lava, which we discover on the slope of Monte Verde, between the beautiful spring of Dornajito and Caravela, are black masses, altered by decomposition, sometimes porous, and with very oblong pores. The basis of these lower lavas is rather wacke than basalt; when it is spongy, it resembles the amygdaloids* of Frankfort-on-the-Main. (* Wakkenartiger mandelstein. Steinkaute.) Its fracture is generally irregular; wherever it is conchoidal, we may presume that the cooling has been more rapid, and the mass has been exposed to a less powerful pressure. These currents of lava are not divided into regular prisms, but into very thin layers, not very regular in their inclination; they contain much olivine, small grains of magnetic iron, and augite, the colour of which often varies from deep leek-green to olive green, and which might be mistaken for crystallized olivine, though no transition from one to the other of these substances exists.* (* Steffens, Handbuch der Oryktognosie tome 1 s. 364. The crystals which Mr. Friesleben and myself have made known under the denomination of foliated olivine (blattriger olivin) belong, according to Mr. Karsten, to the pyroxene augite. Journal des Mines de Freiberg 1791 page 215.) Amphibole is in general very rare at Teneriffe, not only in the modern lithoid lavas, but also in the ancient basalts, as has been observed by M. Cordier, who resided longer at the Canaries than any other mineralogist. Nepheline, leucite, idocrase, and meionite have not yet been seen at the peak of Teneriffe; for a reddish-grey lava, which we found on the slope of Monte Verde, and which contains small microscopic crystals, appears to me to be a close mixture of basalt and analcime.* (* This substance, which M. Dolomieu discovered in the amygdaloids of Catania in Sicily, and which accompanies the stilbites of Fassa in Tyrol, forms, with the chabasie of Hauy, the genus Cubicit of Werner. M. Cordier found at Teneriffe xeolite in an amygdaloid which covers the basalts of La Punta di Naga.) In like manner the lava of Scala, with which the city of Naples is paved, contains a close mixture of basalt, nepheline, and leucite. With respect to this last substance, which has hitherto been observed only at Vesuvius and in the environs of Rome, it exists perhaps at the peak of Teneriffe, in the old currents of lava now covered by more recent ejections. Vesuvius, during a long series of years, has also thrown out lavas without leucites: and if it be true, as M. von Buch has rendered very probable, that these crystals are formed only in the currents which flow either from the crater itself, or very near its brink, we must not be surprised at not finding them in the lavas of the peak. The latter almost all proceed from lateral eruptions, and consequently have been exposed to an enormous pressure in the interior of the volcano.
In the plain of Retama, the basaltic lavas disappear under heaps of ashes, and pumice-stone reduced to powder. Thence to the summit, from 1500 to 1900 toises in height, the volcano exhibits only vitreous lava with bases of pitch-stone* (* Petrosilex resinite. Hauy.) and obsidian. These lavas, destitute of amphibole and mica, are of a blackish brown, often varying to the deepest olive green. They contain large crystals of feldspar, which are not fissured, and seldom vitreous. The analogy of those decidedly volcanic masses with the resinite porphyries* (* Pechstein-porphyr. Werner.) of the valley of Tribisch in Saxony is very remarkable; but the latter, which belong to an extended and metalliferous formation of porphyry, often contain quartz, which is wanting in the modern lavas. When the basis of the lavas of the Malpays changes from pitchstone to obsidian, its colour is paler, and is mixed with grey; in this case, the feldspar passes by imperceptible gradations from the common to the vitreous. Sometimes both varieties meet in the same fragment, as we observed also in the trappean porphyries of the valley of Mexico. The feldsparry lavas of the Peak, of a much less black tinge than those of Arso in the island of Ischia, whiten at the edge of the crater from the effect of the acid vapours; but internally they are not found to be colourless like that of the feldsparry lavas of the Solfatara at Naples, which perfectly resemble the trappean porphyries at the foot of Chimborazo. In the middle of the Malpays, at the height of the cavern of ice, we found among the vitreous lavas with pitch-stone and obsidian bases, blocks of real greenish-grey, or mountain-green phonolite, with a smooth fracture, and divided into thin laminae, sonorous and keen edged. These masses were the same as the porphyrschiefer of the mountain of Bilin in Bohemia; we recognised in them small long crystals of vitreous feldspar.
This regular disposition of lithoid basaltic lava and feldsparry vitreous lava is analogous to the phenomena of all trappean mountains; it reminds us of those phonolites lying in very ancient basalts, those close mixtures of augite and feldspar which cover the hills of wacke or porous amygdaloids: but why are the porphyritic or feldsparry lavas of the Peak found only on the summit of the volcano? Should we conclude from this position that they are of more recent formation than the lithoid basaltic lava, which contains olivine and augite? I cannot admit this last hypothesis; for lateral eruptions may have covered the feldsparry nucleus, at a period when the crater had ceased its activity. At Vesuvius also, we perceive small crystals of vitreous feldspar only in the very ancient lavas of the Somma. These lavas, setting aside the leucite, very nearly resemble the phonolitic ejections of the Peak of Teneriffe. In general, the farther we go back from the period of modern eruptions, the more the currents increase both in size and extent, acquiring the character of rocks, by the regularity of their position, by their division into parallel strata, or by their independence of the present form of the ground.
The Peak of Teneriffe is, next to Lipari, the volcano that has produced most obsidian. This abundance is the more striking, as in other regions of the earth, in Iceland, in Hungary, in Mexico, and in the kingdom of Quito, we meet with obsidians only at great distances from burning volcanoes. Sometimes they are scattered over the fields in angular pieces; for instance, near Popayan, in South America; at other times they form isolated rocks, as at Quinche, near Quito. In other places (and this circumstance is very remarkable), they are disseminated in pearl-stone, as at Cinapecuaro, in the province of Mechoacan,* (* To the west of the city of Mexico.) and at the Cabo de Gates, in Spain. At the peak of Teneriffe the obsidian is not found towards the base of the volcano, which is covered with modern lava: it is frequent only towards the summit, especially from the plain of Retama, where very fine specimens may be collected. This peculiar position, and the circumstance that the obsidian of the Peak has been ejected by a crater which for ages past has thrown out no flames, favour the opinion, that volcanic vitrifications, wherever they are found, are to be considered as of very ancient formation.
Obsidian, jade, and Lydian-stone,* (* Lydischerstein.) are three minerals, which nations ignorant of the use of copper or iron, have in all ages employed for making keen-edged weapons. We see that wandering hordes have dragged with them, in their distant journeys, stones, the natural position of which the mineralogist has not yet been able to determine. Hatchets of jade, covered with Aztec hieroglyphics, which I brought from Mexico, resemble both in their form and nature those made use of by the Gauls, and those we find among the South Sea islanders. The Mexicans dug obsidian from mines, which were of vast extent; and they employed it for making knives, sword-blades, and razors. In like manner the Guanches, (in whose language obsidian was called tabona,) fixed splinters of that mineral to the ends of their lances. They carried on a considerable trade in it with the neighbouring islands; and from the consumption thus occasioned, and the quantity of obsidian which must have been broken in the course of manufacture, we may presume that this mineral has become scarce from the lapse of ages. We are surprised to see an Atlantic nation substituting, like the natives of America, vitrified lava for iron. In both countries this variety of lava was employed as an object of ornament: and the inhabitants of Quito made beautiful looking-glasses with an obsidian divided into parallel laminae.
There are three varieties of obsidian at the Peak. Some form enormous blocks, several toises long, and often of a spheroidal shape. We might suppose that they had been thrown out in a softened state, and had afterwards been subject to a rotary motion. They contain a quantity of vitreous feldspar, of a snow-white colour, and the most brilliant pearly lustre. These obsidians are, nevertheless, but little transparent on the edges; they are almost opaque, of a brownish black, and of an imperfect conchoidal fracture. They pass into pitch-stone; and we may consider them as porphyries with a basis of obsidian. The second variety is found in fragments much less considerable. It is in general of a greenish black, sometimes of murky grey, very seldom of a perfect black, like the obsidian of Hecla and Mexico. Its fracture is perfectly conchoidal, and it is extremely transparent on the edges. I have found in it neither amphibole nor pyroxene, but some small white points, which seem to be feldspar. None of the obsidians of the Peak appear in those grey masses of pearl or lavender-blue, striped, and in separate wedge-formed pieces, like the obsidian of Quito, Mexico, and Lipari, and which resemble the fibrous plates of the crystalites of our glass-houses, on which Sir James Hall, Dr. Thompson, and M. de Bellevue, have published some curious observations.* (* The name crystalites has been given to the crystalized thin plates observed in glass cooling slowly. The term glastenized glass is employed by Dr. Thompson and others to indicate glass which by slow cooling is wholly unvitrified, and has assumed the appearance of a fossil substance, or real glass-stone.)
The third variety of obsidian of the Peak is the most remarkable of the whole, from its connexion with pumice-stone. It is, like that above described, of a greenish black, sometimes of a murky grey, but its very thin plates alternate with layers of pumice-stone. Dr. Thomson's fine collection at Naples contained similar examples of lithoid lava of Vesuvius, divided into very distinct plates, only a line thick. The fibres of the pumice-stone of the Peak are very seldom parallel to each other, and perpendicular to the strata of obsidian; they are most commonly irregular, asbestoidal, like fibrous glass-gall; and instead of being disseminated in the obsidian, like crystalites, they are found simply adhering to one of the external surfaces of this substance. During my stay at Madrid, M. Hergen showed me several specimens in the mineralogical collection of Don Jose Clavijo; and for a long time the Spanish mineralogists considered them as furnishing undoubted proofs, that pumice-stone owes its origin to obsidian, in some degree deprived of colour, and swelled by volcanic fire. I was formerly of this opinion, which, however, must be understood to refer to one variety only of pumice. I even thought, with many other geologists, that obsidian, so far from being vitrified lava, belonged to rocks that were not volcanic; and that the fire, forcing its way through the basalts, the green-stone rocks, the phonolites, and the porphyries with bases of pitchstone and obsidian, the lavas and pumice-stone were no other than these same rocks altered by the action of the volcanoes. The deprivation of colour and extraordinary swelling which the greater part of the obsidians undergo in a forge-fire, their transition into pitch-stone, and their position in regions very distant from burning volcanoes, appear to be phenomena very difficult to reconcile, when we consider the obsidians as volcanic glass. A more profound study of nature, new journeys, and observations made on the productions of burning volcanoes, have led me to renounce those ideas.
It appears to me at present extremely probable, that obsidians, and porphyries with bases of obsidian, are vitrified masses, the cooling of which has been too rapid to change them into lithoid lava. I consider even the pearlstone as an unvitrified obsidian: for among the minerals in the King's cabinet at Berlin there are volcanic glasses from Lipari, in which we see striated crystalites, of a pearl-grey colour, and of an earthy appearance, forming gradual approaches to a granular lithoid lava, like the pearlstone of Cinapecuaro, in Mexico. The oblong bubbles observed in the obsidians of every continent are incontestible proofs of their ancient state of igneous fluidity; and Dr. Thompson possesses specimens from Lipari, which are very instructive in this point of view, because fragments of red porphyry, or porphyry lavas, which do not entirely fill up the cavities of the obsidian, are found enveloped in them. We might say, that these fragments had not time to enter into complete solution in the liquified mass. They contain vitreous feldspar, and augite, and are the same as the celebrated columnar porphyries of the island of Panaria, which, without having been part of a current of lava, seem raised up in the form of hillocks, like many of the porphyries in Auvergne, in the Euganean mountains, and in the Cordilleras of the Andes.
The objections against the volcanic origin of obsidians, founded on their speedy loss of colour, and their swelling by a slow fire, have been shaken by the ingenious experiments of Sir James Hall. These experiments prove, that a stone which is fusible only at thirty-eight degrees of Wedgwood's pyrometer, yields a glass that softens at fourteen degrees; and that this glass, melted again and unvitrified (glastenized), is fusible again only at thirty-five degrees of the same pyrometer. I applied the blowpipe to some black pumice-stone from the volcano of the isle of Bourbon, which, on the slightest contact with the flame, whitened and melted into an enamel.
But whether obsidians be primitive rocks which have undergone the action of volcanic fire, or lavas repeatedly melted within the crater, the origin of the pumice-stones contained in the obsidian of the Peak of Teneriffe is not less problematic. This subject is the more worthy of being investigated, since it is generally interesting to the geology of volcanoes; and since that excellent mineralogist, M. Fleuriau de Bellevue, after having examined Italy and the adjacent islands with great attention, affirms, that it is highly improbable that pumice-stone owes its origin to the swelling of obsidian.
The experiments of M. da Camara, and those I made in 1802, tend to support the opinion, that the pumice-stones adherent to the obsidians of the Peak of Teneriffe do not unite to them accidentally, but are produced by the expansion of an elastic fluid, which is disengaged from the compact vitreous matter. This idea had for a long time occupied the mind of a person highly distinguished for his talents and reputation at Quito, who, unacquainted with the labours of the mineralogists of Europe, had devoted himself to researches on the volcanoes of his country. Don Juan de Larea, one of those men lately sacrificed to the fury of faction, had been struck with the phenomena exhibited by obsidians exposed to a white heat. He had thought, that, wherever volcanoes act in the centre of a country covered with porphyry with base of obsidian, the elastic fluids must cause a swelling of the liquified mass, and perform an important part in the earthquakes preceding eruptions. Without adopting an opinion, which seems somewhat bold, I made, in concert with M. Larea, a series of experiments on the tumefaction of the volcanic vitreous substances at Teneriffe, and on those which are found at Quinche, in the kingdom of Quito. To judge of the augmentation of their bulk, we measured pieces exposed to a forge-fire of moderate heat, by the water they displaced from a cylindric glass, enveloping the spongy mass with a thin coating of wax. According to our experiments, the obsidians swelled very unequally: those of the Peak and the black varieties of Cotopaxi and of Quinche increased nearly five times their bulk.
The colour of the pumice-stones of the Peak leads to another important observation. The sea of white ashes which encircles the Piton, and covers the vast plain of Retama, is a certain proof of the former activity of the crater: for in all volcanoes, even when there are lateral eruptions, the ashes and the rapilli issue conjointly with the vapours only from the opening at the summit of the mountain. Now, at Teneriffe, the black rapilli extend from the foot of the Peak to the sea-shore; while the white ashes, which are only pumice ground to powder, and among which I have discovered, with a lens, fragments of vitreous feldspar and pyroxene, exclusively occupy the region next to the Peak. This peculiar distribution seems to confirm the observations made long ago at Vesuvius, that the white ashes are thrown out last, and indicate the end of the eruption. In proportion as the elasticity of the vapours diminishes, the matter is thrown to a less distance; and the black rapilli, which issue first, when the lava has ceased running, must necessarily reach farther than the white rapilli. The latter appear to have been exposed to the action of a more intense fire.
I have now examined the exterior structure of the Peak, and the composition of its volcanic productions, from the region of the coast to the top of the Piton:—I have endeavoured to render these researches interesting, by comparing the phenomena of the volcano of Teneriffe with those that are observed in other regions, the soil of which is equally undermined by subterranean fires. This mode of viewing Nature in the universality of her relations is no doubt adverse to the rapidity desirable in an itinerary; but it appears to me that, in a narrative, the principal end of which is the progress of physical knowledge, every other consideration ought to be subservient to those of instruction and utility. By isolating facts, travellers, whose labours are in every other respect valuable, have given currency to many false ideas of the pretended contrasts which Nature offers in Africa, in New Holland, and on the ridge of the Cordilleras. The great geological phenomena are subject to regular laws, as well as the forms of plants and animals. The ties which unite these phenomena, the relations which exist between the varied forms of organized beings, are discovered only when we have acquired the habit of viewing the globe as a great whole; and when we consider in the same point of view the composition of rocks, the causes which alter them, and the productions of the soil, in the most distant regions.
Having treated of the volcanic substances of the isle of Teneriffe, there now remains to be solved a question intimately connected with the preceding investigation. Does the archipelago of the Canary Islands contain any rocks of primitive or secondary formation; or is there any production observed, that has not been modified by fire? This interesting problem has been considered by the naturalists of Lord Macartney's expedition, and by those who accompanied captain Baudin in his voyage to the Austral regions. Their opinions are in direct opposition to each other; and the contradiction is the more striking, as the question does not refer to one of those geological reveries which we are accustomed to call systems, but to a positive fact.
Doctor Gillan imagined that he observed, between Laguna and the port of Orotava, in very deep ravines, beds of primitive rocks. This, however, is a mistake. What Dr. Gillan calls somewhat vaguely, mountains of hard ferruginous clay, are nothing but an alluvium which we find at the foot of every volcano. Strata of clay accompany basalts, as tufas accompany modern lavas. Neither M. Cordier nor myself observed in any part of Teneriffe a primitive rock, either in its natural place, or thrown out by the mouth of the Peak; and the absence of these rocks characterizes almost every island of small extent that has an unextinguishied volcano. We know nothing positive of the mountains of the Azores; but it is certain, that the island of Bourbon as well as Teneriffe, exhibits only a heap of lavas and basalts. No volcanic rock rears its head, either on the Gros Morne, or on the volcano of Bourbon, or on the colossal pyramid of Cimandef, which is perhaps more elevated than the Peak of the Canary Islands.
Bory St. Vincent nevertheless asserted, that lavas including fragments of granite have been found on the elevated plain of Retama; and M. Broussonnet informed me, that on a hill above Guimar, fragments of mica-slate, containing beautiful plates of specular iron, had been found. I can affirm nothing respecting the accuracy of this latter statement, which it would be so much the more important to verify, as M. Poli, of Naples, is in possession of a fragment of rock thrown out by Vesuvius,* which I found to be a real mica-slate. (* In the valuable collection of Dr. Thomson, who resided at Naples till 1805, is a fragment of lava enclosing a real granite, which is composed of reddish feldspar with a pearly lustre like adularia, quartz, mica, hornblende, and, what is very remarkable, lazulite. But in general the masses of known primitive rocks, (I mean those which perfectly resemble our granites, our gneiss, and our mica-slates) are very rare in lavas; the substances we commonly denote by the name of granite, thrown out by Vesuvius, are mixtures of nepheline, mica, and pyroxene. We are ignorant whether these mixtures constitute rocks sui generis placed under granite, and consequently of more ancient date; or simply form either intermediate strata on veins, in the interior of the primitive mountains, the tops of which appear at the surface of the globe.) Every thing that tends to enlighten us with respect to the site of the volcanic fire, and the position of rocks subject to its action, is highly interesting to geology.
It is possible, that at the Peak of Teneriffe, the fragments of primitive rocks thrown out by the mouth of the volcano may be less rare than they at present appear to be, and may be heaped together in some ravine, not yet visited by travellers. In fact, at Vesuvius, these same fragments are met with only in one single place, at the Fossa Grande, where they are hidden under a thick layer of ashes. If this ravine had not long ago attracted the attention of naturalists, when masses of granular limestone, and other primitive rocks, were laid bare by the rains, we might have thought them as rare at Vesuvius, as they are, at least in appearance, at the Peak of Teneriffe.
With respect to the fragments of granite, gneiss, and mica-slate, found on the shores of Santa Cruz and Orotava, they were probably brought in ships as ballast. They no more belong to the soil where they lie, than the feldsparry lavas of Etna, seen in the pavements of Hamburg and other towns of the north. The naturalist is exposed to a thousand errors, if he lose sight of the changes, produced on the surface of the globe by the intercourse between nations. We might be led to say, that man, when expatriating himself; is desirous that everything should change country with him. Not only plants, insects, and different species of small quadrupeds, follow him across the ocean; his active industry covers the shores with rocks, which he has torn from the soil in distant climes.
Though it be certain, that no scientific observer has hitherto found at Teneriffe primitive strata, or even those trappean and ambiguous porphyries, which constitute the bases of Etna, and of several volcanoes of the Andes, we must not conclude from this isolated fact, that the whole archipelago of the Canaries is the production of submarine fires. The island of Gomera contains mountains of granite and mica-slate; and it is, undoubtedly, in these very ancient rocks, that we must seek there, as well as on all other parts of the globe, the centre of the volcanic action. Amphibole, sometimes pure and forming intermediate strata, at other times mixed with granite, as in the basanites or basalts of the ancients, may, of itself, furnish all the iron contained in the black and stony lavas. This quantity amounts in the basalt of the modern mineralogists only to 0.20, while in amphibole it exceeds 0. 30.
From several well-informed persons, to whom I addressed myself, I learned that there are calcareous formations in the Great Canary, Forteventura, and Lancerota.* (* At Lancerota calcareous stone is burned to lime with a fire made of the alhulaga, a new species of thorny and arborescent Sonchus.) I was not able to determine the nature of this secondary rock; but it appears certain, that the island of Teneriffe is altogether destitute of it; and that in its alluvial lands it exhibits only clayey calcareous tufa, alternating with volcanic breccia, said to contain, (near the village of La Rambla, at Calderas, and near Candelaria,) plants, imprints of fishes, buccinites, and other fossil marine productions. M. Cordier brought away some of this tufa, which resembles that in the environs of Naples and Rome, and contains fragments of reeds. At the Salvages, which islands La Perouse took at a distance for masses of scoriae, even fibrous gypsum is found.
I had seen, while herborizing between the port of Orotava and the garden of La Paz, heaps of greyish calcareous stones, of an imperfect conchoidal fracture, and analogous to that of Mount Jura and the Apennines. I was informed that these stones were extracted from a quarry near Rambla; and that there were similar quarries near Realejo, and the mountain of Roxas, above Adexa. This information led me into an error. As the coasts of Portugal consist of basalts covering calcareous rocks containing shells, I imagined that a trappean formation, like that of the Vicentin in Lombardy, and of Harutsh in Africa, might have extended from the banks of the Tagus and Cape St. Vincent as far as the Canary Islands; and that the basalts of the Peak might perhaps conceal a secondary calcareous stone. These conjectures exposed me to severe animadversions from M. G.A. de Luc, who is of opinion that every volcanic island is only an accumulation of lavas and scoriae. M. de Luc declares it is impossible that real lava should contain fragments of vegetable substances. Our collections, however, contain pieces of trunks of palm-trees, enclosed and penetrated by the very liquid lava of the isle of Bourbon.
Though Teneriffe belongs to a group of islands of considerable extent, the Peak exhibits nevertheless all the characteristics of a mountain rising on a solitary islet. The lead finds no bottom at a little distance from the ports of Santa Cruz, Orotava, and Garachico: in this respect it is like St. Helena. The ocean, as well as the continents, has its mountains and its plains; and, if we except the Andes, volcanic cones are formed everywhere in the lower regions of the globe.
As the Peak rises amid a system of basalts and old lava, and as the whole part which is visible above the surface of the waters exhibits burnt substances, it has been supposed that this immense pyramid is the effect of a progressive accumulation of lavas; or that it contains in its centre a nucleus of primitive rocks. Both of these suppositions appear to me ill-founded. I think there is as little probability that mountains of granite, gneiss, or primitive calcareous stone have existed where we now see the tops of the Peak, of Vesuvius, and of Etna, as in the plains where almost in our own time has been formed the volcano of Jorullo, which is more than a third of the height of Vesuvius. On examining the circumstances which accompanied the formation of the new island, called Sabrina, in the archipelago of the Azores;* (* At Sabrina island, near St. Michael's, the crater opened at the foot of a solid rock, of almost a cubical form. This rock, surmounted by a small elevated plain perfectly level, is more than two hundred toises in breadth. Its formation was anterior to that of the crater, into which, a few days after its opening, the sea made an irruption. At Kameni, the smoke was not even visible till twenty-six days after the appearance of the upheaved rocks. Philosophical Transactions volume 26 pages 69 and 200, volume 27 page 353. All these phenomena, on which Mr. Hawkins collected very valuable observations during his abode at Santorino, are unfavourable to the idea commonly entertained of the origin of volcanic mountains. They are usually ascribed to a progressive accumulation of liquified matter, and the diffusion of lavas issuing from a central mouth.) on carefully reading the minute and simple narrative, given by the Jesuit Bourguignon of the slow appearance of the islet of the little Kameni, near Santorino; we find that these extraordinary eruptions are generally preceded by a swelling of the softened crust of the globe. Rocks appear above the waters before the flames force their way, or lavas issue from the crater: we must distinguish between the nucleus raised up, and the mass of lavas and scoriae, which successively increases its dimensions.
It is true that from all existing records of revolutions of this kind, the perpendicular height of the stony nucleus appears never to have exceeded one hundred and fifty or two hundred toises; even taking into the account the depth of the sea, the bottom of which had been lifted up: but when considering the great effects of nature, and the intensity of its forces, the bulk of the masses must not deter the geologist in his speculations. Every thing indicates that the physical changes of which tradition has preserved the remembrance, exhibit but a feeble image of those gigantic catastrophes which have given mountains their present form, changed the positions of the rocky strata, and buried sea-shells on the summits of the higher Alps. Doubtless, in those remote times which preceded the existence of the human race, the raised crust of the globe produced those domes of trappean porphyry, those hills of isolated basalt on vast elevated plains, those solid nuclei which are clothed in the modern lavas of the Peak, of Etna, and of Cotopaxi. The volcanic revolutions have succeeded each other after long intervals, and at very different periods: of this we see the vestiges in the transition mountains, in the secondary strata, and in those of alluvium. Volcanoes of earlier date than the sandstone and calcareous rocks have been for ages extinguished; those which are yet in activity are in general surrounded only with breccias and modern tufas; but nothing hinders us from admitting, that the archipelago of the Canaries may exhibit some real rocks of secondary formation, if we recollect that subterranean fires have been there rekindled in the midst of a system of basalts and very ancient lavas.
We seek in vain in the Periplus of Hanno or of Scylax for the first written notions on the eruptions of the Peak of Teneriffe. Those navigators sailed timidly along the coast, anchoring every evening in some bay, and had no knowledge of a volcano distant fifty-six leagues from the coast of Africa. Hanno nevertheless relates, that he saw torrents of light, which seemed to fall on the sea; that every night the coast was covered with fire; and that the great mountain, called the Car of the Gods, appeared to throw up sheets of flame, which rose even to the clouds. But this mountain, situated northward of the island of the Gorilli, formed the western extremity of the Atlas chain; and it is also very uncertain whether the flames seen by Hanno were the effect of some volcanic eruption, or whether they must be attributed to the custom, common to many nations, of setting fire to the forests and dry grass of the savannahs. In our own days similar doubts were entertained by the naturalists, who, in the voyage of d'Entrecasteaux, saw the island of Amsterdam covered with a thick smoke. On the coast of the Caracas, trains of reddish fire, fed by the burning grass, appeared to me, for several nights, under the delusive semblance of a current of lava, descending from the mountains, and dividing itself into several branches.
Though the narratives of Hanno and Scylax, in the state in which they have reached us, contain no passage which we can reasonably apply to the Canary Islands, it is very probable that the Carthaginians, and even the Phoenicians, had some knowledge of the Peak of Teneriffe. In the time of Plato and Aristotle, vague notions of it had reached the Greeks, who considered the whole of the coast of Africa, beyond the Pillars of Hercules, as thrown into disorder by the fire of volcanoes. The Abode of the Blessed, which was sought first in the north, beyond the Riphaean mountains, among the Hyperboreans, and next to the south of Cyrenaica, was supposed to be situated in regions that were considered to be westward, being the direction in which the world known to the ancients terminated. The name of Fortunate Islands was long in as vague signification, as that of El Dorado among the conquerors of America. Happiness was thought to reside at the end of the earth, as we seek for the most exquisite enjoyments of the mind in an ideal world beyond the limits of reality.* (* The idea of the happiness, the great civilization, and the riches of the inhabitants of the north, was common to the Greeks, to the people of India, and to the Mexicans.)
We must not be surprised that, previous to the time of Aristotle, we find no accurate notion respecting the Canary Islands and the volcanoes they contain, among the Greek geographers. The only nation whose navigations extended toward the west and the north, the Carthaginians, were interested in throwing a veil of mystery over those distant regions. While the senate of Carthage was averse to any partial emigration, it pointed out those islands as a place of refuge in times of trouble and public misfortune; they were to the Carthaginians what the free soil of America has become to Europeans amidst their religious and civil dissensions.
The Canaries were not better known to the Romans till eighty-four years before the reign of Augustus. A private individual was desirous of executing the project, which wise foresight had dictated to the senate of Carthage. Sertorius, conquered by Sylla, and weary of the din of war, looked out for a safe and peaceable retreat. He chose the Fortunate Islands, of which a delightful picture had been drawn for him on the shores of Baetica. He carefully combined the notions he acquired from travellers; but in the little that has been transmitted to us of those notions, and in the more minute descriptions of Sebosus and Juba, there is no mention of volcanoes or volcanic eruptions. Scarcely can we recognise the isle of Teneriffe, and the snows with which the summit of the Peak is covered in winter, in the name of Nivaria, given to one of the Fortunate Islands. Hence we might conclude, that the volcano at that time threw out no flames, if it were allowable so to interpret the silence of a few authors, whom we know only by short fragments or dry nomenclatures. The naturalist vainly seeks in history for documents of the first eruptions of the Peak; he nowhere finds any but in the language of the Guanches, in which the word Echeyde denotes, at the same time, hell and the volcano of Teneriffe.
Of all the written testimonies, the oldest I have found in relation to the activity of this volcano dates from the beginning of the sixteenth century. It is contained in the narrative of the voyage of Aloysio Cadamusto, who landed at the Canaries in 1505. This traveller was witness of no eruptions, but he positively affirms that, like Etna, this mountain burns without interruption, and that the fire has been seen by christians held in slavery by the Guanches of Teneriffe. The Peak, therefore, was not at that time in the state of repose in which we find it at present; for it is certain that no navigator or inhabitant of Teneriffe has seen issue from the mouth of the Peak, I will not say flames, but even any smoke visible at a distance. It would be well, perhaps, were the funnel of the Caldera to open anew; the lateral eruptions would thereby be rendered less violent, and the whole group of islands would be less endangered by earthquakes.
The eruptions of the Peak have been very rare for two centuries past, and these long intervals appear to characterize volcanoes highly elevated. The smallest one of all, Stromboli, is almost always burning. At Vesuvius, the eruptions are rarer than formerly, though still more frequent than those of Etna and the Peak of Teneriffe. The colossal summits of the Andes, Cotopaxi and Tungurahua, scarcely have an eruption once in a century. We may say, that in active volcanoes the frequency of the eruptions is in the inverse ratio of the height and the mass. The Peak also had seemed extinguished during ninety-two years, when, in 1798, it made its last eruption by a lateral opening formed in the mountain of Chahorra. In this interval Vesuvius had sixteen eruptions.
The whole of the mountainous part of the kingdom of Quito may be considered as an immense volcano, occupying more than seven hundred square leagues of surface, and throwing out flames by different cones, known under the particular denominations of Cotopaxi, Tungurahua, and Pichincha. The group of the Canary Islands is situated on the same sort of submarine volcano. The fire makes its way sometimes by one and sometimes by another of these islands. Teneriffe alone contains in its centre an immense pyramid terminating in a crater, and throwing out, from one century to another, lava by its flanks. In the other islands, the different eruptions have taken place in various parts; and we nowhere find those isolated mountains to which the volcanic effects are confined. The basaltic crust, formed by ancient volcanoes, seems everywhere undermined; and the currents of lava, seen at Lancerota and Palma, remind us, by every geological affinity, of the eruption which took place in 1301 at the island of Ischia, amid the tufas of Epomeo.
The exclusively lateral action of the peak of Teneriffe is a geological phenomenon, the more remarkable as it contributes to make the mountains which are backed by the principal volcano appear isolated. It is true, that in Etna and Vesuvius the great flowings of lava do not proceed from the crater itself, and that the abundance of melted matter is generally in the inverse ratio of the height of the opening whence the lava is ejected. But at Vesuvius and Etna a lateral eruption constantly terminates by flashes of flame and by ashes issuing from the crater, that is, from the summit of the mountain. At the Peak this phenomenon has not been witnessed for ages: and yet recently, in the eruption of 1798, the crater remained quite inactive. Its bottom did not sink in; while at Vesuvius, as M. von Buch has observed, the greater or less depth of the crater is an infallible indication of the proximity of a new eruption.
I might terminate these geological sketches by enquiring into the nature of the combustible which has fed for so many thousands of years the fire of the peak of Teneriffe;—I might examine whether it be sodium or potassium, the metallic basis of some earth, carburet of hydrogen, or pure sulphur combined with iron, that burns in the volcano;—but wishing to limit myself to what may be the object of direct observation, I shall not take upon me to solve a problem for which we have not yet sufficient data. We know not whether we may conclude, from the enormous quantity of sulphur contained in the crater of the Peak, that it is this substance which keeps up the heat of the volcano; or whether the fire, fed by some combustible of an unknown nature, effects merely the sublimation of the sulphur. What we learn from observation is, that in craters which are still burning, sulphur is very rare; while all the ancient volcanoes end in becoming sulphur-pits. We might presume that, in the former, the sulphur is combined with oxygen, while, in the latter, it is merely sublimated; for nothing hitherto authorises us to admit that it is formed in the interior of volcanoes, like ammonia and the neutral salts. When we were yet unacquainted with sulphur, except as disseminated in the muriatiferous gypsum and in the Alpine limestone, we were almost forced to the belief, that in every part of the globe the volcanic fire acted on rocks of secondary formation; but recent observations have proved that sulphur exists in great abundance in those primitive rocks which so many phenomena indicate as the centre of the volcanic action. Near Alausi, at the back of the Andes of Quito, I found an immense quantity in a bed of quartz, which formed a layer of mica-slate. This fact is the more important, as it is in strict conformity with the conclusions deduced from the observation of those fragments of ancient rocks which are thrown out intact by volcanoes.
We have just considered the island of Teneriffe merely in a geological point of view; we have seen the Peak towering amid fractured strata of basalt and mandelstein; let us examine how these fused masses have been gradually adorned with vegetable clothing, what is the distribution of plants on the steep declivity of the volcano, and what is the aspect or physiognomy of vegetation in the Canary Islands.
In the northern part of the temperate zone, the cryptogamous plants are the first that cover the stony crust of the globe. The lichens and mosses, that develop their foliage beneath the snows, are succeeded by grumina and other phanerogamous plants. This order of vegetation differs on the borders of the torrid zone, and in the countries between the tropics. We there find, it is true, whatever some travellers may have asserted, not only on the mountains, but also in humid and shady places, almost on a level with the sea, Funaria, Dicranum, and Bryum; and these genera, among their numerous species, exhibit several which are common to Lapland, to the Peak of Teneriffe, and to the Blue Mountains of Jamaica. (This extraordinary fact was first observed by M. Swarz. It was confirmed by M. Willdenouw when he carefully examined our herbals, especially the collection of cryptogamous plants, which we gathered on the tops of the Andes, in a region of the world where organic life is totally different from that of the old world.) Nevertheless, in general, it is not by mosses and lichens that vegetation in the countries near the tropics begins. In the Canary Islands, as well as in Guinea, and on the rocky coasts of Peru, the first vegetation which prepares the soil are the succulent plants; the leaves of which, provided with an infinite number of orifices* (* The pores corticaux of M. Decandolle, discovered by Gleichen, and figured by Hedwig.) and cutaneous vessels, deprive the ambient air of the water it holds in solution. Fixed in the crevices of volcanic rocks, they form, as it were, that first layer of vegetable earth with which the currents of lithoid lava are clothed. Wherever these lavas are scorified, and where they have a shining surface, as in the basaltic mounds to the north of Lancerota, the development of vegetation is extremely slow, and many ages may pass away before shrubs can take root. It is only when lavas are covered with tufa and ashes, that the volcanic islands, losing that appearance of nudity which marks their origin, bedeck themselves in rich and brilliant vegetation.
In its present state, the island of Teneriffe, the Chinerfe* (* Of Chinerfe the Europeans have formed, by corruption, Tchineriffe and Teneriffe.) of the Guanches, exhibits five zones of plants, which we may distinguish by the names—region of vines, region of laurels, region of pines, region of the retama, and region of grasses. These zones are ranged in stages, one above another, and occupy, on the steep declivity of the Peak, a perpendicular height of 1750 toises; while fifteen degrees farther north, on the Pyrenees, snow descends to thirteen or fourteen hundred toises of absolute elevation. If the plants of Teneriffe do not reach the summit of the volcano, it is not because the perpetual snow and the cold of the surrounding atmosphere mark limits which they cannot pass; it is the scorified lava of the Malpays, the powdered and barren pumice-stone of the Piton, which impede the migration of plants towards the brink of the crater.
The first zone, that of the vines, extends from the sea-shore to two or three hundred toises of height; it is that which is most inhabited, and the only part carefully cultivated. In the low regions, at the port of Orotava, and wherever the winds have free access, the centigrade thermometer stands in winter, in the months of January and February, at noon, between fifteen and seventeen degrees; and the greatest heats of summer do not exceed twenty-five or twenty-six degrees. The mean temperature of the coasts of Teneriffe appears at least to rise to twenty-one degrees (16.8 degrees Reaumur); and the climate in those parts keeps at the medium between the climate of Naples and that of the torrid zone.
The region of the vines exhibits, among its vegetable productions, eight kinds of arborescent Euphorbia; Mesembrianthema, which are multiplied from the Cape of Good Hope to the Peloponnesus; the Cacalia Kleinia, the Dracaena, and other plants, which in their naked and tortuous trunks, in their succulent leaves, and their tint of bluish green, exhibit distinctive marks of the vegetation of Africa. It is in this zone that the date-tree, the plantain, the sugar-cane, the Indian fig, the Arum Colocasia, the root of which furnishes a nutritive fecula, the olive-tree, the fruit trees of Europe, the vine, and corn are cultivated. Corn is reaped from the end of March to the beginning of May: and the culture of the bread-fruit tree of Otaheite, that of the cinnamon tree of the Moluccas, the coffee-tree of Arabia, and the cacao-tree of America, have been tried with success. On several points of the coast the country assumes the character of a tropical landscape; and we perceive that the region of the palms extends beyond the limits of the torrid zone. The chamaerops and the date-tree flourish in the fertile plains of Murviedro, on the coasts of Genoa, and in Provence, near Antibes, between the thirty-ninth and forty-fourth degrees of latitude; a few trees of the latter species, planted within the walls of the city of Rome, resist even the cold of 2.5 degrees below freezing point. But if the south of Europe as yet only partially shares the gifts lavished by nature on the zone of palms, the island of Teneriffe, situated on the parallel of Egypt, southern Persia, and Florida, is adorned with the greater part of the vegetable forms which add to the majesty of the landscape in the regions near the equator.
On reviewing the different tribes of indigenous plants, we regret not finding trees with small pinnated leaves, and arborescent gramina. No species of the numerous family of the sensitive-plants has migrated as far as the archipelago of the Canary Islands, while on both continents they have been seen in the thirty-eighth and fortieth degrees of latitude. On a more careful examination of the plants of the islands of Lancerota and Forteventura, which are nearest the coast of Morocco, we may perhaps find a few mimosas among many other plants of the African flora.
The second zone, that of the laurels, comprises the woody part of Teneriffe: this is the region of the springs, which gush forth amidst turf always verdant, and never parched with drought. Lofty forests crown the hills leading to the volcano, and in them are found four species of laurel,* (* Laurus indica, L. foetens, L. nobilis, and L. Til. With these trees are mingled the Ardisia excelsa, Rhamnus glandulosus, Erica arborea and E. texo.) an oak nearly resembling the Quercus Turneri* (* Quercus canariensis, Broussonnet.) of the mountains of Tibet, the Visnea mocanera, the Myrica Faya of the Azores, a native olive (Olea excelsa), which is the largest tree of this zone, two species of Sideroxylon, the leaves of which are extremely beautiful, the Arbutus callicarpa, and other evergreen trees of the family of myrtles. Bindweeds, and an ivy very different from that of Europe (Hedera canariensis) entwine the trunks of the laurels; at their feet vegetate a numberless quantity of ferns,* (* Woodwardia radicans, Asplenium palmatum, A. canariensis, A. latifolium, Nothalaena subcordata, Trichomanes canariensis, T. speciosum, and Davallia canariensis.) of which three species* (* Two Acrostichums and the Ophyoglossum lusitanicum.) alone descend as low as the region of the vines. The soil, covered with mosses and tender grass, is enriched with the flowers of the Campanula aurea, the Chrysanthemum pinnatifidum, the Mentha canariensis, and several bushy species of Hypericum.* (* Hypericum canariense, H. floribundum, and H. glandulosum.) Plantations of wild and grafted chestnut-trees form a broad border round the region of the springs, which is the greenest and most agreeable of the whole.
In the third zone (beginning at nine hundred toises of absolute height), the last groups of Arbutus, of Myrica Faya, and of that beautiful heath known to the natives by the name of Texo, appear. This zone, four hundred toises in breadth, is entirely filled by a vast forest of pines, among which mingles the Juniperus cedro of Broussonnet. The leaves of these pines are very long and stiff, and they sprout sometimes by pairs, but oftener by threes in one sheath. Having had no opportunity of examining the fructification, we cannot say whether this species, which has the appearance of the Scotch fir, is really different from the eighteen species of pines with which we are already acquainted in Europe. M. Decandolle is of opinion that the pine of Teneriffe is equally distinct from the Pinus atlantica of the neighbouring mountains of Mogador, and from the pine of Aleppo,* (* Pinus halepensis. M. Decandolle observes, that this species, which is not found in Portugal, but grows on the Mediterranean shores of France, Spain, and Italy, in Asia Minor, and in Barbary, would be better named Pinus mediterranea. It composes the principal part of the pine-forests of the south-east of France, where Gouan and Gerard have confounded it with the Pinus sylvestris. It comprehends the Pinus halepensis, Mill., Lamb., and Desfont., and the Pinus maritima, Lamb.) which belongs to the basin of the Mediterranean, and does not appear to have passed the Pillars of Hercules. We met with these last pines on the slope of the Peak, near twelve hundred toises above the level of the sea. In the Cordilleras of New Spain, under the torrid zone, the Mexican pines extend to the height of two thousand toises. Notwithstanding the similarity of structure existing between the different species of the same genus of plants, each of them requires a certain degree of temperature and rarity in the ambient air to attain its due growth. If in temperate climates, and wherever snow falls, the uniform heat of the soil be somewhat above the mean heat of the atmosphere, it is probable that at the height of Portillo the roots of the pines draw their nourishment from a soil, in which, at a certain depth, the thermometer rises at most to nine or ten degrees.
The fourth and fifth zones, the regions of the retama and the gramina, occupy heights equal to the most inaccessible summits of the Pyrenees. It is the sterile part of the island where heaps of pumice-stone, obsidian, and broken lava, form impediments to vegetation. We have already spoken of those flowery tufts of alpine broom (Spartium nubigenum), which form oases amidst a vast desert of ashes. Two herbaceous plants, the Scrophularia glabrata and the Viola cheiranthifolia, advance even to the Malpays. Above a turf scorched by the heat of an African sun, an arid soil is overspread by the Cladonia paschalis. Towards the summit of the Peak the Urceolarea and other plants of the family of the lichens, help to work the decomposition of the scorified matter. By this unceasing action of organic force the empire of Flora is extended over islands ravaged by volcanoes.
On surveying the different zones of the vegetation of Teneriffe, we perceive that the whole island may be considered as a forest of laurels, arbutus, and pines, containing in its centre a naked and rocky soil, unfit either for pasturage or cultivation. M. Broussonnet observes, that the archipelago of the Canaries may be divided into two groups of islands; the first comprising Lancerota and Forteventura, the second Teneriffe, Canary, Gomera, Ferro, and Palma. The appearance of the vegetation essentially differs in these two groups. The eastern islands, Lancerota and Forteventura, consist of extensive plains and mountains of little elevation; they have very few springs, and bear the appearance, still more than the other islands, of having been separated from the continent. The winds blow in the same direction, and at the same periods: the Euphorbia mauritanica, the Atropa frutescens, and the arborescent Sonchus, vegetate there in the loose sands, and afford, as in Africa, food for camels. The western group of the Canaries presents a more elevated soil, is more woody, and is watered by a greater number of springs.
Though the whole archipelago contains several plants found also in Portugal,* (* M. Willdenouw and myself found, among the plants of the peak of Teneriffe, the beautiful Satyrium diphyllum (Orchis cordata, Willd.) which Mr. Link discovered in Portugal. The Canaries have, in common with the Flora of the Azores, not the Dicksonia culcita, the only arborescent heath found at the thirty-ninth degree of latitude, but the Asplenium palmatum, and the Myrica Faya. This last tree is met with in Portugal, in a wild state. Count Hoffmansegg has seen very old trunks of it; but it was doubtful whether it was indigenous, or imported into that part of our continent. In reflecting on the migrations of plants, and on the geological possibility, that lands sunk in the ocean may have heretofore united Portugal, the Azores, the Canaries, and the chain of Atlas, we conceive, that the existence of the Myrica Faya in western Europe is a phenomenon at least as striking as that of the pine of Aleppo would be at the Azores.), in Spain, at the Azores, and in the north-west of Africa, yet a great number of species, and even some genera, are peculiar to Teneriffe, to Porto Santo, and to Madeira. Such are the Mocanera, the Plocama, the Bosea, the Canarina, the Drusa, and the Pittosporum. A form which may be called northern, that of the cruciform plant (Among the small number of cruciform species contained in the Flora of Teneriffe, we shall here mention Cheiranthus longifolius, l'Herit.; Ch. fructescens, Vent.; Ch. scoparius, Brouss.; Erysimum bicorne, Aiton; Crambe strigosa, and C. laevigata, Brouss.), is much rarer in the Canaries than in Spain and in Greece. Still farther to the south, in the equinoctial regions of both continents, where the mean temperature of the air rises above twenty-two degrees, the cruciform plants are scarcely ever to be seen.
A question highly interesting to the history of the progressive marks of organization on the globe has been very warmly discussed in our own times, that of ascertaining whether the polymorphous plants are more common in the volcanic islands. The vegetation of Teneriffe is unfavourable to the hypothesis that nature in new countries is but little subject to permanent forms. M. Broussonnet, who resided so long at the Canaries, asserts that the variable plants are not more common there than in the south of Europe. May it not to be presumed, that the polymorphous species, which are so abundant in the isle of Bourbon, are assignable to the nature of the soil and climate rather than to the newness of the vegetation?
Before we take leave of the old world to pass into the new, I must advert to a subject which is of general interest, because it belongs to the history of man, and to those fatal revolutions which have swept off whole tribes from the face of the earth. We inquire at the isle of Cuba, at St. Domingo, and in Jamaica, where is the abode of the primitive inhabitants of those countries? We ask at Teneriffe what is become of the Guanches, whose mummies alone, buried in caverns, have escaped destruction? In the fifteenth century almost all mercantile nations, especially the Spaniards and the Portuguese, sought for slaves at the Canary Islands, as in later times they have been sought on the coast of Guinea.* (* The Spanish historians speak of expeditions made by the Huguenots of Rochelle to carry off Guanche slaves. I have some doubt respecting these expeditions, which are said to have taken place subsequently to the year 1530.) The Christian religion, which in its origin was so highly favourable to the liberty of mankind, served afterwards as a pretext to the cupidity of Europeans. Every individual, made prisoner before he received the rite of baptism, became a slave. At that period no attempt had yet been made to prove that the blacks were an intermediate race between man and animals. The swarthy Guanche and the African negro were simultaneously sold in the market of Seville, without a question whether slavery should be the doom only of men with black skins and woolly hair.
The archipelago of the Canaries was divided into several small states hostile to each other, and in many instances the same island was subject to two independent princes. The trading nations, influenced by the hideous policy still exercised on the coast of Africa, kept up intestine warfare. One Guanche then became the property of another, who sold him to the Europeans; several, who preferred death to slavery, killed themselves and their children. The population of the Canaries had considerably suffered by the slave trade, by the depredations of pirates, and especially by a long period of carnage, when Alonzo de Lugo completed the conquest of the Guanches. The surviving remnants of the race perished mostly in 1494, in the terrible pestilence called the modorra, which was attributed to the quantity of dead bodies left exposed in the open air by the Spaniards after the battle of La Laguna. The nation of the Guanches was extinct at the beginning of the seventeenth century; a few old men only were found at Candelaria and Guimar.
It is, however, consoling to find that the whites have not always disdained to intermarry with the natives; but the Canarians of the present day, whom the Spaniards familiarly call Islenos (Islanders), have very powerful motives for denying this mixture. In a long series of generations time effaces the characteristic marks of a race; and as the descendants of the Andalusians settled at Teneriffe are themselves of dark complexion, we may conceive that intermarriages cannot have produced a perceptible change in the colour of the whites. It is very certain that no native of pure race exists in the whole island. It is true that a few Canarian families boast of their relationship to the last shepherd-king of Guimar, but these pretensions do not rest on very solid foundations, and are only renewed from time to time when some Canarian of more dusky hue than his countrymen is prompted to solicit a commission in the service of the king of Spain.
A short time after the discovery of America, when Spain was at the highest pinnacle of her glory, the gentle character of the Guanches was the fashionable topic, as we in our times laud the Arcadian innocence of the inhabitants of Otaheite. In both these pictures the colouring is more vivid than true. When nations, wearied with mental enjoyments, behold nothing in the refinement of manners but the germ of depravity, they are pleased with the idea, that in some distant region, in the first dawn of civilization, infant society enjoys pure and perpetual felicity. To this sentiment Tacitus owed a part of his success, when he sketched for the Romans, subjects of the Caesars, a picture of the manners of the inhabitants of Germany. The same sentiment gives an ineffable charm to the narrative of those travellers who, at the close of the last century, visited the South Sea Islands.
The inhabitants of those islands, too much vaunted (and previously anthropophagi), resemble, under more than one point of view, the Guanches of Teneriffe. Both nations were under the yoke of feudal government. Among the Guanches, this institution, which facilitates and renders a state of warfare perpetual, was sanctioned by religion. The priests declared to the people: "The great Spirit, Achaman, created first the nobles, the achimenceys, to whom he distributed all the goats that exist on the face of the earth. After the nobles, Achaman created the plebeians, achicaxnas. This younger race had the boldness to petition also for goats; but the supreme Spirit answered, that this race was destined to serve the nobles, and that they had need of no property." This tradition was made, no doubt, to please the rich vassals of the shepherd-kings. The faycan, or high priest, also exercised the right of conferring nobility; and the law of the Guanches expressed that every achimencey who degraded himself by milking a goat with his own hands, lost his claim to nobility. This law does not remind us of the simplicity of the Homeric age. We are astonished to see the useful labours of agriculture, and of pastoral life, exposed to contempt at the very dawn of civilization.
The Guanches, famed for their tall stature, were the Patagonians of the old world. Historians exaggerated the muscular strength of the Guanches, as, previous to the voyage of Bougainville and Cordoba, colossal proportions were attributed to the tribe that inhabited the southern extremity of America. I never saw Guanche mummies but in the cabinets of Europe. At the time I visited the Canaries they were very scarce; a considerable number, however, might be found if miners were employed to open the sepulchral caverns which are cut in the rock on the eastern slope of the Peak, between Arico and Guimar. These mummies are in a state of desiccation so singular, that whole bodies, with their integuments, frequently do not weigh above six or seven pounds; or a third less than the skeleton of an individual of the same size, recently stripped of the muscular flesh. The conformation of the skull has some slight resemblance to that of the white race of the ancient Egyptians; and the incisive teeth of the Guanches are blunted, like those of the mummies found on the banks of the Nile. But this form of teeth is the result of art; and on examining more carefully the physiognomy of the ancient Canarians, Blumenbach and other able anatomists have recognized in the cheek bones and the lower jaw perceptible differences from the Egyptian mummies. On opening those of the Guanches, remains of aromatic plants are discovered, among which the Chenopodium ambrosioides is constantly perceived: the bodies are often decorated with small laces, to which are hung little discs of baked earth, which appear to have served as numerical signs, and resemble the quippoes of the Peruvians, the Mexicans, and the Chinese.
The population of islands being in general less exposed than that of continents to the effect of migrations, we may presume that, in the time of the Carthaginians and the Greeks, the archipelago of the Canaries was inhabited by the same race of men as were found by the Norman and Spanish conquerors. The only monument that can throw any light on the origin of the Guanches is their language; but unhappily there are not above a hundred and fifty words extant, and several express the same object, according to the dialect of the different islanders. Independently of these words, which have been carefully noted, there are still some valuable fragments existing in the names of a great number of hamlets, hills, and valleys. The Guanches, like the Biscayans, the Hindoos, the Peruvians, and all primitive nations, named places after the quality of the soil, the shape of the rocks, the caverns that gave them shelter, and the nature of the tree that overshadowed the springs.*
(* It has been long imagined, that the language of the Guanches had no analogy with the living tongues; but since the travels of Hornemann, and the ingenious researches of Marsden and Venturi, have drawn the attention of the learned to the Berbers, who, like the Sarmatic tribes, occupy an immense extent of country in the north of Africa, we find that several Guanche words have common roots with words of the Chilha and Gebali dialects. We shall cite, for instance, the words:
TABLE OF WORDS.
Column 1: Word.
Column 2: In Guanche.
Column 3: In Berberic.
Heaven : Tigo : Tigot. Milk : Aho : Acho. Barley : Temasen : Tomzeen. Basket : Carianas : Carian. Water : Aenum : Anan.
I doubt whether this analogy is a proof of a common origin; but it is an indication of the ancient connexion between the Guanches and Berbers, a tribe of mountaineers, in which the ancient Numidians, Getuli, and Garamanti are confounded, and who extend themselves from the eastern extremity of Atlas by Harutsh and Fezzan, as far as the oasis of Siwah and Augela. The natives of the Canary Islands called themselves Guanches, from guan, man; as the Tonguese call themselves bye, and tongui, which have the same signification as guan. Besides the nations who speak the Berberic language are not all of the same race; and the description which Scylax gives, in his Periplus, of the inhabitants of Cerne, a shepherd people of tall stature and long hair, reminds us of the features which characterize the Canarian Guanches.)
The greater attention we direct to the study of languages in a philosophical point of view, the more we must observe that no one of them is entirely distinct. The language of the Guanches would appear still less so, had we any data respecting its mechanism and grammatical construction; two elements more important than the form of words, and the identity of sounds. It is the same with certain idioms, as with those organized beings that seem to shrink from all classification in the series of natural families. Their isolated state is merely apparent; for it ceases when, on embracing a greater number of objects, we come to discover the intermediate links. Those learned enquirers who trace Egyptians wherever there are mummies, hieroglyphics, or pyramids, will imagine perhaps that the race of Typhon was united to the Guanches by the Berbers, real Atlantes, to whom belong the Tibboes and the Tuarycks of the desert: but this hypothesis is supported by no analogy between the Berberic and Coptic languages, which are justly considered as remnants of the ancient Egyptian.
The people who have succeeded the Guanches are descended from the Spaniards, and in a more remote degree from the Normans. Though these two races have been exposed during three centuries past to the same climate, the latter is distinguished by the fairer complexion. The descendants of the Normans inhabit the valley of Teganana, between Punta de Naga and Punta de Hidalgo. The names of Grandville and Dampierre are still pretty common in this district. The Canarians are a moral, sober, and religious people, of a less industrious character at home than in foreign countries. A roving and enterprising disposition leads these islanders, like the Biscayans and Catalonians, to the Philippines, to the Ladrone Islands, to America, and wherever there are Spanish settlements, from Chile and La Plata to New Mexico. To them we are in a great measure indebted for the progress of agriculture in those colonies. The whole archipelago does not contain 160,030 inhabitants, and the Islenos are perhaps more numerous in the new continent than in their own country.
PASSAGE FROM TENERIFE TO SOUTH AMERICA. THE ISLAND OF TOBAGO. ARRIVAL AT CUMANA.
We left the road of Santa Cruz on the 25th of June, and directed our course towards South America. We soon lost sight of the Canary Islands, the lofty mountains of which were covered with a reddish vapour. The Peak alone appeared from time to time, as at intervals the wind dispersed the clouds that enveloped the Piton. We felt, for the first time, how strong are the impressions left on the mind from the aspect of those countries situated on the limits of the torrid zone, where nature appears at once so rich, so various, and so majestic. Our stay at Teneriffe had been very short, and yet we withdrew from the island as if it had long been our home.
Our passage from Santa Cruz to Cumana, the most eastern part of the New Continent, was very fine. We cut the tropic of Cancer on the 27th; and though the Pizarro was not a very fast sailer, we made, in twenty days, the nine hundred leagues, which separate the coast of Africa from that of the New Continent. We passed fifty leagues west of Cape Bojador, Cape Blanco, and the Cape Verd islands. A few land birds, which had been driven to sea by the impetuosity of the wind followed us for several days.
The latitude diminished rapidly, from the parallel of Madeira to the tropic. When we reached the zone where the trade-winds are constant, we crossed the ocean from east to west, on a calm sea, which the Spanish sailors call the Ladies' Gulf, el Golfo de las Damas. In proportion as we advanced towards the west, we found the trade-winds fix to eastward.
These winds, the most generally adopted theory of which is explained in a celebrated treatise of Halley,* are a phenomenon much more complicated than most persons admit. (* The existence of an upper current of air, which blows constantly from the equator to the poles, and of a lower current, which blows from the poles to the equator, had already been admitted, as M. Arago has shown, by Hooke. The ideas of the celebrated English naturalist are developed in a Discourse on Earthquakes published in 1686. "I think (adds he) that several phenomena, which are presented by the atmosphere and the ocean, especially the winds, may be explained by the polar currents."—Hooke's Posthumous Works page 364.) In the Atlantic Ocean, the longitude, as well as the declination of the sun, influences the direction and limits of the trade-winds. In the direction of the New Continent, in both hemispheres, these limits extend beyond the tropics eight or nine degrees; while in the vicinity of Africa, the variable winds prevail far beyond the parallel of 28 or 27 degrees. It is to be regretted, on account of the progress of meteorology and navigation, that the changes of the currents of the equinoctial atmosphere in the Pacific are much less known than the variation of these same currents in a sea that is narrower, and influenced by the proximity of the coasts of Guinea and Brazil. The difference with which the strata of air flow back from the two poles towards the equator cannot be the same in every degree of longitude, that is to say, on points of the globe where the continents are of very different breadths, and where they stretch away more or less towards the poles.
It is known, that in the passage from Santa Cruz to Cumana, as in that from Acapulco to the Philippine Islands, seamen are scarcely ever under the necessity of working their sails. We pass those latitudes as if we were descending a river, and we might deem it no hazardous undertaking if we made the voyage in an open boat. Farther west, on the coast of Santa Martha and in the Gulf of Mexico, the trade-wind blows impetuously, and renders the sea very stormy.* (* The Spanish sailors call the rough trade-winds at Carthagena in the West Indies los brisotes de Santa Martha; and in the Gulf of Mexico, las brizas pardas. These latter winds are accompanied with a grey and cloudy sky.)
The wind fell gradually the farther we receded from the African coast: it was sometimes smooth water for several hours, and these short calms were regularly interrupted by electrical phenomena. Black thick clouds, marked by strong outlines, rose on the east, and it seemed as if a squall would have forced us to hand our topsails; but the breeze freshened anew, there fell a few large drops of rain, and the storm dispersed without our hearing any thunder. Meanwhile it was curious to observe the effect of several black, isolated, and very low clouds, which passed the zenith. We felt the force of the wind augment or diminish progressively, according as small bodies of vesicular vapour approached or receded, while the electrometers, furnished with a long metallic rod and lighted match, showed no change of electric tension in the lower strata of the air. It is by help of these squalls, which alternate with dead calms, that the passage from the Canary Islands to the Antilles, or southern coast of America, is made in the months of June and July.
Some Spanish navigators have lately proposed going to the West Indies and the coasts of Terra Firma by a course different from that which was taken by Columbus. They advise, instead of steering directly to the south in search of the trade-winds, to change both latitude and longitude, in a diagonal line from Cape St. Vincent to America. This method, which shortens the way, cutting the tropic nearly twenty degrees west of the point where it is commonly cut by pilots, was several times successfully adopted by Admiral Gravina. That able commander, who fell at the battle of Trafalgar, arrived in 1802 at St. Domingo, by the oblique passage, several days before the French fleet, though orders of the court of Madrid would have forced him to enter Ferrol with his squadron, and stop there some time.
This new system of navigation shortens the passage from Cadiz to Cumana one-twentieth; but as the tropic is attained only at the longitude of forty degrees, the chance of meeting with contrary winds, which blow sometimes from the south, and at other times from the south-west, is more unfavourable. In the old system, the disadvantage of making a longer passage is compensated by the certainty of catching the trade-winds in a shorter space of time, and keeping them the greater part of the passage. At the time of my abode in the Spanish colonies, I witnessed the arrival of several merchant-ships, which from the fear of privateers had chosen the oblique course, and had had a very short passage.
Nothing can equal the beauty and mildness of the climate of the equinoctial region on the ocean. While the trade wind blew strongly, the thermometer kept at 23 or 24 degrees in the day, and at 22 or 22.5 degrees during the night. The charm of the lovely climates bordering on the equator, can be fully enjoyed only by those who have undertaken the voyage from Acapulco or the coasts of Chile to Europe in a very rough season. What a contrast between the tempestuous seas of the northern latitudes and the regions where the tranquillity of nature is never disturbed! If the return from Mexico or South America to the coasts of Spain were as expeditious and as agreeable as the passage from the old to the new continent, the number of Europeans settled in the colonies would be much less considerable than it is at present. To the sea which surrounds the Azores and the Bermuda Islands, and which is traversed in returning to Europe by the high latitudes, the Spaniards have given the singular name of Golfo de las Yeguas (the Mares' Gulf). Colonists who are not accustomed to the sea, and who have led solitary lives in the forests of Guiana, the savannahs of the Caracas, or the Cordilleras of Peru, dread the vicinity of the Bermudas more than the inhabitants of Lima fear at present the passage round Cape horn.
To the north of the Cape Verd Islands we met with great masses of floating seaweeds. They were the tropic grape, (Fucus natans), which grows on submarine rocks, only from the equator to the fortieth degree of north and south latitude. These weeds seem to indicate the existence of currents in this place, as well as to south-west of the banks of Newfoundland. We must not confound the latitudes abounding in scattered weeds with those banks of marine plants, which Columbus compares to extensive meadows, the sight of which dismayed the crew of the Santa Maria in the forty-second degree of longitude. I am convinced, from the comparison of a great number of journals, that in the basin of the Northern Atlantic there exist two banks of weeds very different from each other. The most extensive is a little west of the meridian of Fayal, one of the Azores, between the twenty-fifth and thirty-sixth degrees of latitude.* (* It would appear that Phoenician vessels came "in thirty days' sail, with an easterly wind," to the weedy sea, which the Portuguese and Spaniards call mar de zargasso. I have shown, in another place (Views of Nature Bohn's edition page 46), that the passage of Aristotle, De Mirabil. (ed. Duval page 1157), can scarcely be applied to the coasts of Africa, like an analogous passage of the Periplus of Scylax. Supposing that this sea, full of weeds, which impeded the course of the Phoenician vessels, was the mar de zargasso, we need not admit that the ancients navigated the Atlantic beyond thirty degrees of west longitude from the meridian of Paris.) The temperature of the Atlantic in those latitudes is from sixteen to twenty degrees, and the north winds, which sometimes rage there very tempestuously, drive floating isles of seaweed into the low latitudes as far as the parallels of twenty-four and even twenty degrees. Vessels returning to Europe, either from Monte Video or the Cape of Good Hope, cross these banks of Fucus, which the Spanish pilots consider as at an equal distance from the Antilles and Canaries; and they serve the less instructed mariner to rectify his longitude. The second bank of Fucus is but little known; it occupies a much smaller space, in the twenty-second and twenty-sixth degrees of latitude, eighty leagues west of the meridian of the Bahama Islands. It is found on the passage from the Caiques to the Bermudas.
Though a species of seaweed* (* The baudreux of the Falkland Islands; Fucus giganteus, Forster; Laminaria pyrifera, Lamour.) has been seen with stems eight hundred feet long, the growth of these marine cryptogamia being extremely rapid, it is nevertheless certain, that in the latitudes we have just described, the Fuci, far from being fixed to the bottom, float in separate masses on the surface of the water. In this state, the vegetation can scarcely last longer than it would in the branch of a tree torn from its trunk; and in order to explain how moving masses are found for ages in the same position, we must admit that they owe their origin to submarine rocks, which, lying at forty or sixty fathoms' depth, continually supply what has been carried away by the equinoctial currents. This current bears the tropic grape into the high latitudes, toward the coasts of Norway and France; and it is not the Gulf-stream, as some mariners think, which accumulates the Fucus to the south of the Azores.
The causes that unroot these weeds at depths where it is generally thought the sea is but slightly agitated, are not sufficiently known. We learn only, from the observations of M. Lamouroux, that if the fucus adhere to the rocks with the greatest firmness before its fructification, it separates with great facility after that period, or during the season which suspends its vegetation like that of the terrestrial plants. The fish and mollusca which gnaw the stems of the seaweeds no doubt contribute also to detach them from their roots.
From the twenty-second degree of latitude, we found the surface of the sea covered with flying-fish,* (* Exocoetus volitans.) which threw themselves up into the air, twelve, fifteen, or eighteen feet, and fell down on the deck. I do not hesitate to speak on a subject of which voyagers discourse as frequently as of dolphins, sharks, sea-sickness, and the phosphorescence of the ocean. None of these topics can fail to afford interesting observations to naturalists, provided they make them their particular study. Nature is an inexhaustible source of investigation, and in proportion as the domain of science is extended, she presents herself to those who know how to interrogate her, under forms which they have never yet examined.
I have named the flying-fish, in order to direct the attention of naturalists to the enormous size of their natatory bladder, which, in an animal of 6.4 inches, is 3.6 inches long, 0.9 of an inch broad, and contains three cubic inches and a half of air. As this bladder occupies more than half the size of the fish, it is probable that it contributes to its lightness. We may assert that this reservoir of air is more fitted for flying than swimming; for the experiments made by M. Provenzal and myself have proved, that, even in the species which are provided with this organ, it is not indispensably necessary for the ascending movement to the surface of the water. In a young flying-fish, 5.8 inches long, each of the pectoral fins, which serve as wings, presented a surface to the air of 3 7/16 square inches. We observed, that the nine branches of nerves, which go to the twelve rays of these fins, are almost three times the size of the nerves that belong to the ventral fins. When the former of these nerves are excited by galvanic electricity, the rays which support the membrane of the pectoral fin extend with five times the force with which the other fins move when galvanised by the same metals. Thus, the fish is capable of throwing itself horizontally the distance of twenty feet before retouching the water with the extremity of its fins. This motion has been aptly compared to that of a flat stone, which, thrown horizontally, bounds one or two feet above the water. Notwithstanding the extreme rapidity of this motion, it is certain, that the animal beats the air during the leap; that is, it alternately extends and closes its pectoral fins. The same motion has been observed in the flying scorpion of the rivers of Japan: they also contain a large air-bladder, with which the great part of the scorpions that have not the faculty of flying are unprovided. The flying-fish, like almost all animals which have gills, enjoy the power of equal respiration for a long time, both in water and in air, by the same organs; that is, by extracting the oxygen from the atmosphere as well as from the water in which it is dissolved. They pass a great part of their life in the air; but if they escape from the sea to avoid the voracity of the Dorado, they meet in the air the Frigate-bird, the Albatross, and others, which seize them in their flight. Thus, on the banks of the Orinoco, herds of the Cabiai, which rush from the water to escape the crocodile, become the prey of the jaguar, which awaits their arrival.
I doubt, however, whether the flying-fish spring out of the water merely to escape the pursuit of their enemies. Like swallows, they move by thousands in a right line, and in a direction constantly opposite to that of the waves. In our own climates, on the brink of a river, illumined by the rays of the sun, we often see solitary fish fearlessly bound above the surface as if they felt pleasure in breathing the air. Why should not these gambols be more frequent with the flying-fish, which from the strength of their pectoral fins, and the smallness of their specific gravity, can so easily support themselves in the air? I invite naturalists to examine whether other flying-fish, for instance the Exocoetus exiliens, the Trigla volitans, amid the T. hirundo, have as capacious an air-bladder as the flying-fish of the tropics. This last follows the heated waters of the Gulf-stream when they flow northward. The cabin-boys amuse themselves with cutting off a part of the pectoral fins, and assert, that these wings grow again; which seems to me not unlikely, from facts observed in other families of fishes.
At the time I left Paris, experiments made at Jamaica by Dr. Brodbelt, on the air contained in the natatory bladder of the sword-fish, had led some naturalists to think, that within the tropics, in sea-fish, that organ must be filled with pure oxygen gas. Full of this idea, I was surprised at finding in the air-bladder of the flying-fish only 0.04 of oxygen to 0.94 of azote and 0.02 of carbonic acid. The proportion of this last gas, measured by the absorption of lime-water in graduated tubes, appeared more uniform than that of the oxygen, of which some individuals yielded almost double the quantity. From the curious phenomena observed by MM. Biot, Configliachi, and Delaroche, we might suppose, that the swordfish dissected by Dr. Brodbelt had inhabited the lower strata of the ocean, where some fish* have as much as 0.92 of oxygen in the air-bladder. (* Trigla cucullus.)
On the 3rd and 4th of July, we crossed that part of the Atlantic where the charts indicate the bank of the Maal-stroom; and towards night we altered our course to avoid the danger, the existence of which is, however, as doubtful as that of the isles Fonseco and St. Anne. It would have been perhaps as prudent to have continued our course. The old charts are filled with rocks, some of which really exist, though most of them are merely the offspring of those optical illusions which are more frequent at sea than in inland places. As we approached the supposed Maal-stroom, we observed no other motion in the waters than the effect of a current which bore to the north-west, and which hindered us from diminishing our latitude as much as we wished. The force of this current augments as we approach the new continent; it is modified by the configuration of the coasts of Brazil and Guiana, and not by the waters of the Orinoco and the Amazon, as some have supposed.
From the time we entered the torrid zone, we were never weary of admiring, at night, the beauty of the southern sky, which, as we advanced to the south, opened new constellations to our view. We feel an indescribable sensation when, on approaching the equator, and particularly on passing from one hemisphere to the other, we see those stars, which we have contemplated from our infancy, progressively sink, and finally disappear. Nothing awakens in the traveller a livelier remembrance of the immense distance by which he is separated from his country, than the aspect of an unknown firmament. The grouping of the stars of the first magnitude, some scattered nebulae, rivalling in splendour the milky way, and tracts of space remarkable for their extreme blackness, give a peculiar physiognomy to the southern sky. This sight fills with admiration even those who, uninstructed in the several branches of physical science, feel the same emotion of delight in the contemplation of the heavenly vault, as in the view of a beautiful landscape, or a majestic site. A traveller needs not to be a botanist, to recognize the torrid zone by the mere aspect of its vegetation. Without having acquired any notions of astronomy, without any acquaintance with the celestial charts of Flamsteed and De La Caille, he feels he is not in Europe, when he sees the immense constellation of the Ship, or the phosphorescent Clouds of Magellan, arise on the horizon. The heavens and the earth,—everything in the equinoctial regions, presents an exotic character.
The lower regions of the air were loaded with vapours for some days. We saw distinctly for the first time the Southern Cross only on the night of the 4th of July, in the sixteenth degree of latitude. It was strongly inclined, and appeared from time to time between the clouds, the centre of which, furrowed by uncondensed lightnings, reflected a silvery light. If a traveller may be permitted to speak of his personal emotions, I shall add, that on that night I experienced the realization of one of the dreams of my early youth.
When we begin to fix our eyes on geographical maps, and to read the narratives of navigators, we feel for certain countries and climates a sort of predilection, which we know not how to account for at a more advanced period of life. These impressions, however, exercise a considerable influence over our determinations; and from a sort of instinct we endeavour to connect ourselves with objects on which the mind has long been fixed as by a secret charm. At a period when I studied the heavens, not with the intention of devoting myself to astronomy, but only to acquire a knowledge of the stars, I was disturbed by a feeling unknown to those who are devoted to sedentary life. It was painful to me to renounce the hope of beholding the beautiful constellations near the south pole. Impatient to rove in the equinoctial regions, I could not raise my eyes to the starry firmament without thinking of the Southern Cross, and recalling the sublime passage of Dante, which the most celebrated commentators have applied to that constellation:—
Io mi volsi a man' destra e posi mente All' altro polo, e vidi quattro stelle Non viste mai fuorch' alla prima gente.
Goder parea lo ciel di lor fiammelle; O settentrional vedovo sito Poiche privato sei di mirar quelle!
The pleasure we felt on discovering the Southern Cross was warmly shared by those of the crew who had visited the colonies. In the solitude of the seas we hail a star as a friend, from whom we have long been separated. The Portuguese and the Spaniards are peculiarly susceptible of this feeling; a religious sentiment attaches them to a constellation, the form of which recalls the sign of the faith planted by their ancestors in the deserts of the New World.
The two great stars which mark the summit and the foot of the Cross having nearly the same right ascension, it follows that the constellation is almost perpendicular at the moment when it passes the meridian. This circumstance is known to the people of every nation situated beyond the tropics, or in the southern hemisphere. It has been observed at what hour of the night, in different seasons, the Cross is erect or inclined. It is a timepiece which advances very regularly nearly four minutes a-day, and no other group of stars affords to the naked eye an observation of time so easily made. How often have we heard our guides exclaim in the savannahs of Venezuela, or in the desert extending from Lima to Truxillo, "Midnight is past, the Cross begins to bend!" How often those words reminded us of that affecting scene, where Paul and Virginia, seated near the source of the river of Lataniers, conversed together for the last time, and where the old man, at the sight of the Southern Cross, warns them that it is time to separate.
The last days of our passage were not so felicitous as the mildness of the climate and the calmness of the ocean had led us to hope. The dangers of the sea did not disturb us, but the germs of a malignant fever became manifest on board our vessel as we drew near the Antilles. Between decks the ship was excessively hot, and very much crowded. From the time we passed the tropic, the thermometer was at thirty-four or thirty-six degrees. Two sailors, several passengers, and, what is remarkable enough, two negroes from the coast of Guinea, and a mulatto child, were attacked with a disorder which appeared to be epidemic. The symptoms were not equally alarming in all the cases; nevertheless, several persons, and especially the most robust, fell into delirium after the second day. No fumigation was made. A Gallician surgeon, ignorant and phlegmatic, ordered bleedings, because he attributed the fever to what he called heat and corruption of the blood. There was not an ounce of bark on board; for we had emitted to take any with us, under the impression that this salutary production of Peru could not fail to be found on board a Spanish vessel.
On the 8th of July, a sailor, who was near expiring, recovered his health from a circumstance worthy of being mentioned. His hammock was so hung, that there was not ten inches between his face and the deck. It was impossible to administer the sacrament in this situation; for, agreeably to the custom on board Spanish vessels, the viaticum must be carried by the light of tapers, and followed by the whole crew. The patient was removed into an airy place near the hatchway, where a small square berth had been formed with sailcloth. Here he was to remain till he died, which was an event expected every moment; but passing from an atmosphere heated, stagnant, and filled with miasma, into fresher and purer air, which was renewed every instant, he gradually revived from his lethargic state. His recovery dated from the day when he quitted the middle deck; and as it often happens in medicine that the same facts are cited in support of systems diametrically opposite, this recovery confirmed our doctor in his idea of the inflammation of the blood, and the necessity of bleeding, evacuating, and all the asthenic remedies. We soon felt the fatal effects of this treatment.
For several days the pilot's reckoning differed 1 degree 12 minutes in longitude from that of my time. This difference was owing less to the general current, which I have called the current of rotation, than to that particular movement, which, drawing the waters toward the north-west, from the coast of Brazil to the Antilles, shortens the passage from Cayenne to Guadaloupe.* (* In the Atlantic Ocean there is a space where the water is constantly milky, though the sea is very deep. This curious phenomenon exists in the parallel of the island of Dominica, very near the 57th degree of longitude. May there not be in this place some sunken volcanic islet, more easterly still than Barbadoes?) On the 12th of July, I thought I might foretell our seeing land next day before sunrise. We were then, according to my observations, in latitude 10 degrees 46 minutes, and west longitude 60 degrees 54 minutes. A few series of lunar distances confirmed the chronometrical result; but we were surer of the position of the vessel, than of that of the land to which we were directing our course, and which was so differently marked in the French, Spanish, and English charts. The longitudes deduced from the accurate observations of Messrs. Churruca, Fidalgo, and Noguera, were not then published.