currents will be entirely reversed, and continue so as long as the desert winds blow towards the sea. To the same cause does the Count attribute the trade winds, asserting, that till now they have been ascribed to chance. We suspect that he has yet something to read before he is au courant with modern science, from which the word chance is wholly expunged, and which has already given us very satisfactory reasons for the constancy of these great friends to the navigator. We extract a part of this passage.

"Les vents donc, tant réguliers qu'irréguliers, ne peuvent naître que du concours et de l'influence des cinq fluides élémentaires, et comme j'ai déjà fait remarquer, que c'est dans les canaux, et dans les cônes volcaniques que ces fluides se concentrent le plus, je donne dans mon ouvrage les preuves de ce que les vents, soit périodiques, soit permanens, ne regnent que dans les régions volcaniques.'

Volcanic fire itself the Count believes to be purely material. Its principles are filtration and fermentation, springing from the pressure of the upper strata. Where fermentation exists there must be heat, and the commencement of ignition. Fermentation is augmented by the effect of the gases and the water which results from it; it is also augmented in proportion as the heat penetrates more deeply into the inferior strata, where the substances are more compact, and consequently yield a greater abundance of matter, which contributes to the fire. All these parts are decomposed, combined, and penetrate the mineral crust, and form first little veins, which are increased by the fusible substances they meet with in their passage, and circulate in the manner of rivulets, which, by a gradual accumulation, form rivers and precipitate themselves into the sea. According to this, the existence of volcanoes is a necessary evil, in order to facilitate the discharge of so much combustible matter. A part certainly goes towards that warmth which is required by vegetation; but if the surplus had not any means of discharging itself, it would consume the whole planet, and consequently without volcanoes the world could not exist. The sea Count de Bylandt considers to be an indispensable agent, and without it no volcanic eruption could take place. The action of this sea-water on the volcanic matter, therefore, is one of the immediate causes of eruption, by increasing fermentation; the second accelerating cause is the mouth of the volcano, by which a column of atmospheric air is precipitated within, and the contact of which with the inflammable gases redoubles the force of dilatation. At every respiration of the volcano a fresh column is absorbed, and the action commences afresh. The detonations are also to be attributed to two causes; the first of which is heat, which, separating the masses with

violence, hurls them against other masses, which are equally in the act of bursting, and produces the most frightful noise. The other cause is the superabundance of hydrogen, the sudden expansion and condensation of which make the column of air vibrate, and these effects, added to the electric shocks, produce those rapid detonations which succeed each other with so much rapidity. Lava can only flow, and not be thrown out; for its compactness, its specific gravity, and the consequent adherence of its parts, hold it in a solid body; and, as the expansive property of the fire ceases at the mouth of the volcano, the lava is left to its own weight, which drags it along, while the aëriform gases, in their rapid ascension, take with them the stones and lighter substances. As far as the base of the cone, lava flows with perfect regularity, as it is then subject to the inclination of the axis of the volcano, but this is lost at the foot of the cone, whence it flows irregularly, shaping its course according to the surface of the ground.

It is impossible to stop a current of lava; but, according to our author, it is easy to turn its course, by a projecting angle of not less than 45 degrees. On meeting this angle, more or less large, according to circumstances, the lava separates itself into two streams, and leaves a space in the middle, free from its destructive effects. This experiment was repeated frequently with success during two eruptions of Mount Vesuvius. The direction of the lava has nothing whatever to do with the atmospheric wind; because, in the first place, the heat and continual bursts of fire, which proceed from the mouth of an active volcano, dilate the air to such a degree that it would repel the most violent tempest; and, in the second, atmospheric movements are, as it were, paralyzed during an eruption-but it is the volcano itself which sends forth the most terrible wind; it is from its entrails that the rarefied air of its deep caverns, uniting with that which is contained in the column of water, and that sucked in at every respiration, is dilated to infinity, and is capable of carrying the cinders from Vesuvius even to Constantinople and Syria, which actually happened in the eruptions of the years 79, 472, and 1779.

The proportions which volcanoes bear to the force they require in order to send forth their contents, and which corresponds exactly with double the height of the cone, the impossibility of primitive mountains ever becoming volcanic, the division of the volcanic cone into triangles, and the bearing which this measurement above the level of the surrounding earth has upon the depth of the fire, the oblique axis of the interior of the cone, the centrifugal force which sends out the matter by means of spiral projection, &c., are ably set forth, though we hope that more arrangement and method exists in the work itself.

VOL. XV. NO. XXIX.

G

An

application of the theory to the volcanoes of Sicily and Italy is also very interesting, and several promised maps will tend much to further elucidation.

Should the Count prove what he says, and fulfil the promises he makes in his avant-propos, he will open a wide field for the geologist, and at all events it is hardly possible for an observing person to travel for thirty years, and watch a great many eruptions, and examine a great many volcanoes, without exhibiting important and highly interesting facts; but we do hope that the three forthcoming volumes will not be so puzzling to the reader as the avant-propos has been to the reviewer. We can face conceit; we can even divest a subject of the incumbrances of irrelevant matter; but want of order and method presents difficulties scarcely to be overcome.

The work of M. Amedée Burat is of a very different character; it is a plain, careful, matter-of-fact statement of observations made by himself in the interior of France. It formed part of a more extensive undertaking, which, owing to various circumstances, especially " the new direction given to geology by Messrs. Von Buch and Elie de Beaumont," has been suppressed. The portion now published is confined to an account of the formations of Cantal, the Velay chain of mountains, the Haut Vivarais, and the Coyrons, and gives particulars which it seems have hitherto escaped the notice of geologists. The volcanic formation of central France, says M. Burat, forms an exception to the general situation of volcanoes, which are for the most part placed along the sea-coast, and their age, being posterior to that of the last tertiary deposits, does not allow of the intervention of sea-water among the causes of eruption. To establish this agency of salt water as an invariable law, is, the author thinks, incompatible with the present state of modern science, which leans much more to the dynamic theory.

The centre of southern France is occupied by a vast primitive plain of irregular form, every where surrounded by secondary formations. But, in the eastern part of this plain, volcanic fire has found an issue, and changed its surface by an aggregation of enormous masses, and by local heavings or disturbances which accompanied the successive emission of volcanic matter, during the three volcanic periods, termed by geologists trachytic, basaltic, and lavic.

No country has as yet so much contributed to a correct knowledge of extinct volcanoes as this portion of the European continent; it has set aside the systems of the German school, and it affords an admirable specimen for the study of those phenomena which arise from the heavings of the soil. M. Burat throws a

rapid glance over the whole of this district, and then takes the trachytic formation separately under consideration, and of which the groups of Cantal and the Monts Dorés constitute the best example. The author afterwards proceeds to the basaltic period, and leads us through Auvergne, and the Velay and Vivarais chains. In treating of the lavic period he conducts us through the Chaine des Puys. He minutely details the mineralogical part of these formations, and to those who have not studied the spot thoroughly his labours will form a valuable help; while, to those who have, they will present a table of reference. It appears to us to be a solid treatise on a certain portion of volcanic geology, and is written without display or pretension, evidently keeping in view the advancement of science rather than that of the author.

ART. IV.-Wanderungen durch Sicilien und die Levante. (Wanderings through Sicily and the Levant.) Vol. I. 12mo.-Berlin:

1834.

We have long since avowed our liking for German travellers, with their jovial love of good eating and drinking, their philosophico-poetical enthusiasm, and that extreme subjectivity,* seemingly inherent in the German temperament, which colours every scene, whether graphic or dramatic, with the peculiar tone of the feelings and theories of the observer. Nor do we now recant this our profession of faith, although we honestly confess that, in the tenor of the volume before us, there is a something less to our taste, a something-literally a je ne sais quoi, for in very truth we know not whether to call it ultra-subjectivity, or an objectivity growing out of subjectivity. We submit this difficult question to the judgment of the reader, and hasten to furnish him with the means of forming an opinion.

The anonymous German traveller, whose wanderings we are about to review, appears to be the accepted lover-we trust, the affianced bridegroom-of a certain Annunziata, to whom he dedicates his book in a tender elegy.-We mean a tender German poem, in the classical elegiac metre; which elegiac metre, soit dit en passant, is the only ancient metre that ever fully satisfies our ear in any modern language. But not only is the book dedicated to the beloved Annunziata, it is, from beginning to end, addressed to her; being, in fact, a series of letters in the form of a journal.

For the philosophical German use of the words subjectivity and objectivity, see F. Q. R., Vol. Xl., p. 223.

Now, assuredly no mode of book-making could be more propitious to subjective views than this of addressing every remark to a person who cares more for the writer than for what he sees, more for his sentiments than for his observations or opinions. Perhaps this very circumstance might put the author upon his guard, for never before have we seen German travels so objective, unless, indeed, we except one point which we are about to censure, and which might arise, perhaps, from his forgetting, whilst writing to la dame de ses pensées, everything save herself and her portion, if not rather her want, of knowledge; for we find in this journal a very superfluous quantity of ancient and middle-age history; nearly as much information about Syracuse (the old, not the new,) and Agrigentum as about Palermo and Messina, more about our school acquaintance, Gelo and Hiero, Agathocles and either Dionysius-than about the King Francis I. of the two Sicilies, or his father, the late, or his son, the present, King Ferdinand.

The book, nevertheless, is not a bad, nay, it is a good book; and of that, too, we will now enable the reader to judge for himself, first observing that, although the book be new, these Wanderings having been communicated to the world only last year, they were undertaken in 1822, and that any political animadversions which they may induce must therefore be referred to that period; at least as far as the present volume, containing only the Wanderings in Sicily and Malta, is concerned. To how recent an epoch they may have been prolonged in the Levant, we have no present grounds for even conjecturing, the elegiac dedication being dated simply Naples, without any A. D.

Our Wanderer landed at Palermo, in May, 1822, and, after a very short residence there, proceeded westward upon his tour round Sicily, diversifying the circuit by a few trips inwards, when attracted by any inland sights. He visited Trapani, Marsalawhere he drank Mr. Woodhouse's Marsala wine upon the very spot of its growth and manufacture, and takes the opportunity of informing us that, in London, this said Marsala wine is held to be the first of white wines, having quite superseded poor oldfashioned Madeira-meaning, perhaps, Cape Madeira. But to proceed with the tour. Our Wanderer next visited Mazzara, Girgenti, Syracuse, Catania, the crater of Mount Etna, and Messina-we mention only the principal places-thence he crossed the Faro, or straits, to Reggio, admiring, by the way, the beautiful atmospheric architecture of the Fata Morgana, looked at Calabria, and braved the classic terrors of Scylla and Charybdis on his return to Messina. He then made a maritime trip to the Lipari Islands, and the miniature but active volcano of Strombolicontemptible after Mongibello!-and again returned to Messina,