,

as well as the hornblende slates *, which I saw near Angostura, on the banks of the Lower Oroonoko, belong to the mountains of Pacaraimo and of Parime, stretching from West to East+ in the interior of the continent, and not in a direction parallel with the coast, between the mouths of the River of Amazons and the Oroonoko. But notwithstanding we find no chain of mountains at the North-East extremity of Terra Firma, that has the same direction as the Archipelago of the Smaller West India islands, it does not follow from this circumstance alone, that the volcanic mountains of the Archipelago may not have belonged originally to the continent, to the littoral chain of Caraccas and Cumana +.

* Hornblendschiefer, amphibolites schistoïdes of Brongniart. + From the cataracts of Atures toward the Rio Esquibo. This chain of Pacaraimo divides the waters of the Carony from those of the Rio Parime, or Rio de Aguas Blancas. See my Analyse de L'Atlas geograph. Pl. xvi.

Among the numerous examples, which the structure of the Globe displays, we shall mention only the inflexion at a right angle formed by the High Alps toward the maritime Alps, in Europe; and the Belour-tagh, which joins transversely the Mouz-tagh with Himalaya, in Asia. Amid the prejudices, which impede the progress of mineralogical geography, we may reckon, 1st, The supposition of a perfect uniformity of direction in the chains of mountains; 2d, The hypothesis of a continuity in all the chains; 3d, The supposition, that the highest summits determine the direction of a

In opposing the objections of some celebrated naturalists, I am far from maintaining the ancient contiguity of all the Smaller West India islands. I am rather inclined to consider them as islands heaved up by fire, and ranged in that regular line, of which we find the most striking examples in so many volcanic hills in Auvergne, in Mexico, and in Peru. The geognostical constitution of the Archipelago appears, from the little we know respecting it, to be very similar to that of the Azores and Canary islands. Primitive formations are nowhere seen above ground*;

central chain; 4th, The idea, that in all places, where great rivers take rise, we may admit great table-lands, or very high mountains.

According to Messrs. Moreau de (Journal de Physique, tom. lxx, p. 129).

Jonnès and Cortes
Dupuget and Le-

blond imagined they had recognized granite in the mountain Pelèe of Martinico, and in other parts of the Archipelago (Voyage aux Antilles, tom. i, p. 87, 274, and 410). Gneiss has been mentioned as forming a part of the solfatara, at St. Kit's. We cannot be too much on our guard against these indications of rocks in works, the authors of which are less familiarized with the name than with the object. How great was my surprise, when, during my stay at Santa-Fede-Bogota, Mr. Mutis showed me in the Journal de Physique for 1786, p. 321, a paper of Mr. Leblond, where this tra veller, in other respects accurate, describes the table-land of Bogota, where he resided during some years, as granitic. We find there nothing but secondary formations, sand-stones and gypsum; not even detached fragments of granite.

must

we find only what belongs unquestionably to volcanoes, feldspar-lavas, dolerites, basaltes, agglomerated scoriæ, tufas, and pumice stones. Among the limestone formations distinguish those, which are essentially subordinate to volcanic tufas *, from those which appear to be the work of madrepores and other zoophytes. The latter, according to Mr. Moreau de Jonnès, seem to lie on shoals of a volcanic nature. Those mountains, which present traces of the action of fire more or less recent, and some of which reach nearly nine hundred toises of elevation, are all situate on the western skirt of the Smaller West India islands. Each island

We have noticed some of these above (vol. iii, p. 575), after Mr. von Buch, at Lancerota, and at Fortaventura, in the System of the Canary Islands. Among the smaller islands of the West Indies, the following islets are entirely calcareous, according to Mr. Cortes: Marigalante, la Desirad, the Grand Terre of Guadaloupe, and the Grenadillas. According to the observations of this naturalist, Curasoa and Bonaire (Buen Ayre) present only calcareous formations. Mr. Cortes divides the West India islands into, 1st, those containing at once primitive, secondary, and volcanic formations, like the greater islands; 2nd, those entirely calcareous, (or at least so considered) as Marigalante and Curasoa; 3rd, those at once volcanic and calcareous, as Antigua, St. Bartholomew, St. Martin, and St. Thomas; 4th, those which display volcanic rocks only, as St. Vincent, St. Lucia, and St. Eustatia.

See the observations of Mr. Amie, in his Rapport sur PEtat du Volcan de la Guadeloupe en 1797, p. 17.

is not the effect of one single heaving up: most of them appear to consist of isolated masses, which have been progressively united together*. The matter has not been emitted from one mouth, but from several: so that a single island of small extent contains a whole system of volcanoes, regions purely basaltic, and others covered with recent lavas. The volcanoes still burning are those of St. Vincent, St. Lucia, and Guadaloupe. The first threw out lavas in 1718 and 1812: in the second there is a continual formation of sulphur by the condensation of vapours, which issue from the crevices of an ancient crater. The last eruption of the volcano of Guadaloupe took place in 1797. The Solfatara of St. Christopher's was still burning in 1692. At Martinico, Vauclin, Montagne Pelée, and the crater surrounded by the five paps of Carbet, must be considered as three extinguished volcanoes. The effects of thunder have been often confounded in that place with subterranean fire. No good observation has confirmed the supposed eruption of the 22nd of January, 1792. The group of volcanoes in the Caribbee islands

See above, vol. i, ch. 2, p. 255.

These phenomena are very well indicated in the fine geological charts, that Mr. Moreau de Jonnès is going to publish.

Journal de Mines, tom. iii, p. 59. In order to exhibit in one point of view the whole system of the volcanoes of the

resembles that of the volcanoes of Quito and Los Pastos; craters, with which the subterranean fire does not appear to communicate, are ranged on the same line with burning craters, and alternate with them.

Smaller West India islands, I shall trace in this note the direction of the islands from South to North.-Grenada, an ancient crater, filled with water; boiling springs; basalts between St. George and Goave.-St. Vincent, a burning volcano.— St. Lucia, a very active solfatara, named Oualibou, two or three hundred toises high; jets of hot water, by which small basins are periodically filled.-Martinico, three great extinguished volcanoes; Vauclin, the paps of Carbet, which are perhaps the most elevated summits of the smaller islands, and Montagne Pelée. (The height of this last mountain is probably 800 toises; according to Leblond, 670 toises; according to Dupuget, 736 toises. Between Vauclin and the feldspar-lavas of the paps of Carbet is found, as Mr. Moreau de Jonnès asserts, in a neck of land, a region of ancient basalts called La Roche carrée). Thermal waters of Prêcheur and Lameutin.-Dominica, completely volcanised.— Guadaloupe, an active volcano, the height of which, according to Leboucher, is 799 toises, to Amie, 850 toises.-Montserrat, a solfatara, fine porphyritic lavas with large crystals of feldspar and hornblende, near Galloway, according to Mr. Nugent.-Nevis, a solfatara.-St. Christopher's, a solfatara at Mount Misery.-St. Eustatia, a crater of an extinguished volcano, surrounded by pumice stones. (Trinidad, which is traversed by a chain of primitive slates, appears to have anciently formed a part of the littoral chain of Cumana, and not of the system of the mountains of the Caribbee islands. Edwards's History of the West Indies, vol. iii, p. 275. Dauxion Lavaysse, vol. ii, p. 60.