NOTES TO PRECEDING SECTION. 



135 



piqiiB (le France, t. iii. p. 109, and Fiedler, Reise durch 

 Gnecheiihiiid. Th. ii. S. 4fi9 and 5S4.) 



^02 (p. 73.) — Appearances of new islands near San Mi- 

 guel, one of the Azore* : llth June, 1638, 31st December, 

 1719, I3ih June, 1811. 



'•JtW (p. 73.) — Pr6vost. in Bulletin de la Soci6te {^(^alogique, 

 t. ii. p. 34 ; Friedrich Hoffmann, liinterlassene Werke, Bd. 

 ii. S. 451—456. 



204 (p. 73.)_«' Accedunt vicini et perpetui Aetnae montis 

 ignes et insularum Aeolidum, veluti ipsis undis alatur irt- 

 cendium ; neque enini aliter durare tot seculis tantus ignis 

 potuisset, nisi humoris nutrimentis aleretur." (Justin, 

 Hist. Philipp. ir. i.) The volcanic theory with which the 

 physical description of Sicily here begins is extremely in- 

 tricate. Deep-lying beds of sulphur and rosin, an extreme- 

 ly thin crust, full of cavities and readily divided ; violent mo- 

 tion of the waves of the sea, which, as they strike togeth- 

 er, draw down air (the wind) for the maintenance of the 

 fire : such are the elements of the theory of Trogus. Ashe 

 presents himself as a physiognomist in Pliny (xi. 52), we 

 may presume that he did not limit himself to history alone ; 

 but many of his works are lost to us. The view according 

 to which air was forced into the interior of the earth, there 

 to influence the volcanic force, is moreover connected with 

 the notions of the ancients on the inflience exerted by the 

 direction of the wind upon the intensity of the fire which 

 burns in ^tna, in Hiera and Stromboli (see the remarkable 

 passage in Strabo, lib. vi. p. 275 and 276). The mountain- 

 ous island of Stromboli (Strongyle) was therefore regarded 

 as the seat of ^olus, " the controller of the winds," as the 

 sailors foretold the weather from the violence of the vol- 

 canic eruptions of Stromboli. Such a connection between 

 the eruptions of a small volcano and the stateof the barome- 

 ter and the quarter of the wind is still recognised (vide Leop. 

 von Buch, Descr. phys. des lies Canaries, p. 334 ; Hoffmann 

 in Poggend. Ann. Bd. xxvi. S. 8) ; although it must be allow- 

 ed that all our present knowledge of volcanic phenomena, and 

 the slight alterations in the pressure of the air that accom- 

 pany our winds, do not enable us to offer any satisfactory 

 explanation of the fact. Bembo, brought up as a youth by 

 Greek exiles in Sicily, gives a pleasant narrative of his 

 wanderings, and in his " .^tna Dialogus" (middle of the 

 16th century) advances the theory of the penetration of sea 

 water to the focus of the volcano, and of the necessity of 

 the neighbourhood of the sea. On ascending jEtna the 

 following question is thrown out: " Explana potius nobis 

 quae petimus, ea incendia unde oriantur et orta quomodo 

 perdurent ? In omni tellure nuspiam majores fistulae aut 

 meatus ampliores sunt quam in locis, quae vel mari vicina 

 sunt, vel a mari protinus alluuntur : mare erodit ilia facil- 

 lime pergitque in viscera terrae. Itaque cum in aliena 

 regna sibi viam faciat, ventis etiam facit ; ex quo fit, ut 

 loca quaeque maritima maxime terraemotibus subjecta sint, 

 parum mediterranea. Habes quum in sulfuris venas venti 

 furentes inciderint, unde incendia oriantur Aetnae tuae. 

 Vides, quae mare in radicibus habeat, quae stilfurea sit, 

 quae ca\rernosa, quae a mari aliquando perforata ventos 

 admiserit aestuantes, per quos idouea flammae materies in- 

 cenderetur. 



205 (p. 73.) — See Gay-Lussac, sur les Volcans, in den 

 Annales de Chimie, t. xxii. p. 427; and Bischoff, Warme- 

 lehre, S. 372. Reactions of the volcanic hearth through 

 tensive columns of water, viz., when the expansive force of 

 the vapour surpasses the hydrostatic pressure, are proclaim- 

 ed by the erupticms of smoke and aqueous vapour, which 

 are observed at diflTerent times in Lancerote, Iceland, and 

 the Kurile islands during eruptions of the neighbouring 

 volcanoes. 



206 (p. 73.)— Abel-Remusat, Lettre a Mr. Cordier, in the 

 Annales des Mines, t. v. p. 137. 



207 (p. 73.)— Humboldt, Asie centrale, t. ii. p. 30—33, 

 38-52, 70—80, and 426—428. The existence of active vol- 

 canoes in Cordofan, 135 miles from the Red Sea, has lately 

 been denied by Riippell (Reise in Nubien, 1829). 



208 (p. 74.)— Dufrenoy et Elie de Beaumont, Explication 

 de la Carte g6ologique de la France, t. i. p. 89. 



209 (p. 74.)— Sophocl. Philoctet. v. 971 and 972. On the 

 conjectural epoch of the extinction of the Lemnian fire in 

 the time of Alexander, vide Buttmann in Museum der Al- 

 terthumswissenschaft, Bd. i. 1807, S. 295 ; Dureau de la 

 Malle in Malte-Brun, Annales des Voyages, t. ix. 1809, p. 

 5 ; Ukert in Bertuch, Geogr. Ephemeriden, Bd. xxxix. 1812^ 

 S. 361 ; Rhode, Res Lemnicae, 1829, p. 8, and Walter iiber 

 Abnahme der vulkan. Thatigkeit in historischen Zeiten, 

 1844, S. 24. The hydrographical conception of Lemnos by 

 Choiseul makes it extremely probable that the extinct found- 

 ations of Moschylos, together with the island Chryse, Phil- 

 octetes' desolate abode (Otfried Miiller, Minyer, S. 300) 

 have been long swallowed up by the sea. Reefs and shoals 

 to the North-east of Lemnos still show the spot where the 

 iEgsean Sea possessed an active volcano like Jctna, Vesuvi- 

 us, Stromboli, and that of the Lipari isles. 



210 (p. 7i.)—Vide Reinwardt and Hoffmann in Poggen- 

 dorlf 's Aanalen, Bd. xii. S. 607 j Leop. von Buch, Descr. 



des lies Canaries, p. 424,426. The argillaceous nrad erup- 

 tions of Carguairazo, when tne volcano crumbled together 

 in 1698, the Lrjdazales of Iguaiata, and the Moya of Pelileo, 

 are volcanic appearances of the same nature in the high- 

 lands of Quito. 



211 (p. 74.)— In a profile of the environs of Tezcuco, To- 

 tonilco, and Moran, (Atlas g6ographique et Physique, PL 

 Vii.) which I originally (18U3) designed for a Pasigrafia 

 geognostica destinada a! uso de los Jovenes del Colegio de 

 iMineria de Mexico, but which was never published, I en- 

 titled (1832) the Plutonic and volcanic eruptive rocks endo- 

 genous, (that which is engendered in the interior,) the sedi- 

 mentary and flcEtz rocks exogenous (externally engender- 

 ed). PasigraphicaJly the former were indicated by an arrow 

 directed upwards, f , the latter by an arrow directed down- 

 wards, I , signs which had certain pictorial advantages, and 

 permitted the nature of the rock to be shown without having 

 recourse to those very unpicturesque and arbitrarily-shaped 

 cones which are generally seen in such profile drawings. 

 The titles endogenous and exogenous were borrowed from 

 Decandolle, who uses the former in connection with mono- 

 cotyledonous, the latter with dicotyledonous plants. But 

 Mohl's more careful vegetable anatomy has shown, that ia 

 the strict sense of the words the growth of monocotyledo- 

 nous vegetables does not proceed from within, nor that of 

 decotyledonous plants/rom without. ( Vide Link, Elementa 

 philosophiae botanicae, t. i. 1837, p. 287 ; Endlicher und 

 Unger, Grundziige der Botanik, 1843, S. 89 ; and Jussieu, 

 Trait6 de Botanique, t. i. p. 85.) What I call endogenous, 

 Lyell, in his Principles of Geology, 1833, vol. iii. p. 374, 

 characterises by the expression " netherformed" or " hy- 

 pogene rocks." 



212 (p. 74.) — Vide Leop. von Buch iiber Dolomit als 

 Gebirgsart, 1823, S. 36 ; and farther, Ueber den Grad 

 der Fliissigkeit, welchen man plutonisohen Felsarten bei 

 ihrem Heraustreten zuschreiben soil, wie iiber Entstehung 

 des Gneuss aus Schiefern durch Einwirkung des Granits 

 und der mit seiner Erhebung verbundeneu Stoffe, as well 

 as in the Abhandl. der Akad. der Wissench. zu Berlin aus 

 dem Jahre 1842, S. 58 und 63, and in the Jahrb. fiir wis- 

 senschaftliche Kritik, 1840, S. 195. 



213 (p. 75.)— Darwin, Volcanic Islands, 1844, p. 49 and 

 154. 



214 (p. 75.) — Moreau de Jonnes, Hist. phys. des Antilles, 

 t. i. p. 136, 138, and 543 ; Humboldt, Relation historique, 

 t. iii. p. 367. 



215 (p. 75.) — At Teguiza ; Leop. von Buch, Canarische 

 Inselna, S. 301. 



216 (p. 75.)— TitZe above, p. 4. 



2ir (p. 75.)— Bernhard Cotta, Geognosie, 1839, S. 273. 



218 (p. 75.) — Leop. von Buch iiber Granit und Gneuss in 

 den Abhandl. der Berl. Akad. aus dem J. 1842, S. 60. 



219 (p, 75.) — In the granite of the Kolivan Lake, which 

 rises like walls, and is divided into parallel narrow ledges, 

 felspar and albite predominate, titanitic crystals are rare. 

 Humboldt, Asie centrale, t. i. p. 295 ; Gustav Rose, Reise 

 nach dem Ural, Bd. i. S. 524. 



220 (p. 75.)— Humboldt, Relation historique, t. ii. p. 99. 



221 (p, 75.) — See the drawing of Biri-tau, which I took 

 from the south, with Kirghish tents pitched, in Rose, Reise, 

 Bd. i. S. 584. On granite balls scaling off concentrically, 

 vide Humboldt, Rel. hist. t. ii. p. 597 ; and Essai g6ogn 

 sur le Gisement des Roches, p. 78. 



222 (p. 75.)— Humboldt, Asie centrale, t. i. p. 299—311, 

 and the drawings in Rose's Reise, Bd. i. S. 611, in which 

 the curves of the granitic layers pointed out by Leop. von 

 Buch as characteristic, are repeated. 



223 (p, 75.)— This remarkable stratification was first de- 

 scribed by Weiss, in Karsten's Archiv fiir Bergbau und 

 Hiittenwesen, Bd. xvi. 1827, S. 5. 



224 (p. 76.) — Dufrenoy et Elie de Beaumont, G6ologie de 

 la France, t. i. p. 130. 



225 (p. 76.)— An important part is played by these sub- 

 stratified diorites near Steben, in the Nailaer Mountain dis- 

 trict, a country where I was engaged in mining work in the 

 last century, and with which some of the happiest associa- 

 tions of my youth are connected. Vide Friedr. Hoffmann 

 in PoggendorfPs Annalen, Bd. xvi. S. 558. 



226 (p. 76.) — In the southern and Baschkir-Ural ; vide 

 Rose, Reise, Bd. ii. S. 171. 



227 (p. 76.)— G. Rose, Reise nach dem Ural, Bd. ii. S. 

 47 — 52. On the identity of Elaeolite and Nepheline (in the 

 latter the quantity of lime is somewhat larger), vide Schee- 

 rer, in Poggend. Annalen, Bd. xlix. S. 359-381. 



228 (p. 77.) — See the admirable papers of Mitscherlich, in 

 the Abhandlungen der Berl. Akad. for the years 1822 and 

 1823, S. 25—41 ; in PoggendorfFs Annalen, Bd. x. S. 137— 

 152, Bd. xi. S. 323—332, Bd. xli. S. 213—216 (Gustav Rose 

 iiber Bildung des Kalkspaths und Aragonits in Poggend, 

 Ann. Bd. xlii. S. 353—366 ; Haidinger, in the Transactions 

 of the Royal Society of Edinbu^rgh, 1827, p. 148). 



229 (p, 77.) — Lyell, Principles of Geology, vol. iii. p. 353 

 and 359. 



330 (p. 78.)— -The statements here made of the relationa 



