NOTES. clxvii 



to reach the summit of Chimborazo, printed in Schumacher's Jahrbuch for 1837, 

 S. 204 and 205 (and reprinted in my Kleinere Schriften, Bd. i. S. 160 and 161); 

 and the second time, in 1837, in a memoir on the Highland of Quito, in Poggend. 

 Ann. Bd. xl. S. 165. I there said, having previously strongly opposed my 

 friend's statement that all the volcanoes of the Andes are similarly constituted : 

 " Very recent times have shown that the different zones do not always present 

 the same (mineralogical) composition, the same ingredients. Sometimes we have 

 trachytes proper characterised by glassy felspar, as at the Peak of Teneriffe and 

 the Siebengebirge near Bonn, where some albite is associated with the felspar: 

 these are felspar- trachytes, which, as active volcanoes, frequently produce 

 obsidian and pumice ; sometimes melaphyres and doleritic compositions of 

 labradorite and augite, more nearly approaching basalt : as at Etna, Stromboli, 

 and Chimborazo; sometimes albite with hornblende prevails: as in the newly 

 so-called Andesites of Chili, and the magnificent columns of Pisoje, described 

 as diorite-porphyry, near Popayan, at the foot of the Volcano of Purace', or in 

 the Mexican Volcano of Jorullo; and lastly, sometimes leucite-ophyrs, mix- 

 tures of leucite and augite: as in the Somma, the old wall of the crater of 

 elevation of Vesuvius." By an accidental misunderstanding of this passage, 

 which bears many traces of the imperfect state of knowledge at that time (still 

 assigning felspar instead of oligoclase to the Peak of Teneriffe, labradorite to 

 Chimborazo, and albite to the Volcano of Toluca), the ingenious investigator 

 Abich, himself both a chemist and a geologist, erroneously attributed to me (Pog- 

 gend. Ann. Bd. li. 1840, S. 523) the invention of the name andesite as that of a 

 trachytic, widely diffused, albite-containing rock; and gave to a new species of 

 felspar, first analysed by him, and respecting which there is still some obscurity, 

 the name of andesine, " in consideration of the rock (from Marmato near 

 Popayan) in which it was first recognised." Andesine (pseudo-albite in ande- 

 site) would be placed intermediately between labradorite and oligoclase : at the 

 temperature of 15 Reaumur its specific gravity is 2'733; that of the andesite, 

 in which the andesine was found, is 3' 593. Gustav Rose, and subsequently 

 Charles Deville (Etudes de Lithologie, p. 30), have doubted the independent 

 existence of andesine as a species : as it rests only on a single analysis of Abich's, 

 that made by Francis (Poggend. Ann. Bd. lii. 1841, S. 472), in the laboratory 

 of Heinrich Rose, of the felspathic portion of a fine piece of diorite-porphyry 

 which I brought from Pisoje near Popayan, indicating, indeed, great resemblance 

 to the andesine from Marmato analysed by Abich, but yet the composition being 

 different. There is still much greater uncertainty, as to the so-called andesine, 

 in the syenite of the Vosges (from the Ballon de Servance and from Coravillers, 

 analysed by Delesse). Compare G. Rose, in the already often-cited Zcitsclmft 



