NOTES. CXill 



fragable proof of the site of the fiery hearth of the volcano of Jorullo having been 

 in or below the syenite, which shows itself at the surface for some considerable 

 extent, a few leagues to the southward, on the left bank of the Rio de las 

 Balsas which flows into the Pacific." In Lipari, near Caneto, Dolomieu, and, 

 in 1832, the excellent geognost Friedrich Hoffmann even found in hard masses of 

 obsidian enclosed fragments of granite formed out of pale-red feldspar, black 

 mica, and a little light-gray quartz. (Poggendorfs Annalen der Physik, Bel. 

 xxvi. S. 49.) 



( 43; ) p. 302. Strabo, lib. xiii. p. 579 and 628 ; Hamilton, Researches in 

 Asia Minor, vol. ii. chap. 39. The westernmost of the three cones, now called 

 Kara Devlit, is 530 feet above the plain, and has poured out a great stream of 

 lava towards Koula. Hamilton counted above thirty small cones in the neigh- 

 bourhood. The three orifices or abysses (&6&poi and tyvvai of Strabo) are cra- 

 ters on conical mounts composed of scoria? and lavas. 



( 438 ) p. 302. Erman, Reise urn die Erde, Bd. iii. S. 538 ; Kosmos, Bd. iv. 

 Anm. 25 (English edition, Note 349). Postels (Voyage autour du Monde, par 

 le Cap. Lutke, Partie Hist. t. iii. p. 76) and Leopold von Buch (Description 

 physique des lies Canaries, p. 448) speak of the resemblance to the Hornitos of 

 Jorullo. Erman, in a manuscript which he kindly communicated to me, de- 

 scribes a great number of truncated cones of scorise in the enormous lava field 

 east of the Baidar mountains in the peninsula of Kamtschatka. 



( 4S9 ) p. 304. Porzio, Opera omnia, Med., Phil., et Mathem., in unum col- 

 lecta, 1736 ; according to Dufre'noy, Me'moires pour servir a une Description 

 ge'ologique de la France, t. iv. p. 274. In the 9th edition of Sir Charles Lyell's 

 Principles of Geology, 1853, p. 369, all genetic questions are treated with great 

 fullness and praiseworthy impartiality. So long ago as 1 749, Bouguer (Figure 

 tie la Terre, 1749, p. Ixvi.) was not averse from the idea of the volcano of Pi- 

 chincha having been upheaved : " II n'est pas impossible que le rocher, qui est 

 biule et noir, ait e'te' souleve' par Faction du feu souterrain." Compare also 

 p. xci. 



( 44 ) p. 304. Zeitschrift fur allgemeine Erdkunde, Bd. iv. S. 398. 



( 441 ) p. 304. For the more certain determination of the minerals composing 

 the Mexican volcanoes, older and more recent collections made by myself and by 

 Pieschel have been compared. 



( 442 ) p. 305. The fine marble of la Puebla comes from the quarries of 

 Tecali, Totomehuacan, and Portachuelo, south of the high trachytic mountain 

 el Pizarro : also near the terrace-pyramid of Cholula, on the road to la Puebla, 

 I have seen limestone crop out. 



.(* 4S ) p. 306. The Cofre de Prote,to the south-east of the Fuerte or Castillo 

 VOL. IV } L 



