NOTES. Ixi 



(Desfontaines). Compare Gumprecht, die Mineralquellen auf dem Festlande von 

 Africa (1851), S. 140144. 



( 27 ) p. 198. Humboldt, Essai Politique sur la Nouv. Espagne, 2 erne ed. t. 

 iii. (1827) p. 190. 



0") p. 199. Relat. hist, du Voyage aux Regions Equinoxiales, t. ii. p. 98. 

 Kosmos, Bd. i. S 230 (English edition, p. 208). The hot springs of Carlsbad 

 also owe their origin to granite (Von Buch in Poggend. Ann., Bd. xii. S. 416); 

 as do the hot springs of Momay in Thibet, visited by Joseph Hooker, which break 

 forth 16,000 feet above the sea, with a temperature of 124'8, near Changokhang 

 (Himalayan Journals, vol. ii. p. 133). 



C" 72 ) p. 199. Boussingault, Considerations sur les Eaux thermales des Cor- 

 dilleres, in the Annales de Cliimie et de Physique, t. Hi. 1833, pp. 188 190. 



( 273 ) p. 200. Captain Newbold, " On the Temperature of the Wells and Rivers 

 in India and Egypt" (Phil. Trans. 1845, pt. i. p. 127). 



( 274 ) p. 201. Sartorius von Waltershausen, Physisch-geographische Skizze 

 von Island, init besonderer Riicksicht auf volkanische Erscheinungen, 1847, S. 

 128 132. (Physico-Geographic Sketch of Iceland, with especial regard to 

 Volcanic Phenomena.) Bunsen and Descloiseaux, in the Comptes rendus des 

 Se'ances de 1'Acad. des Sciences, t. xxiii. 1846, p. 935; Bunsen, in the Anna- 

 len der Chemie und Pharmacie, Bd. Ixii. 1847, S. 27 45. Lottin and Robert 

 had already ascertained that the temperature of the column of water in the 

 Geysir diminishes from below upwards. Among the 40 silex-containing springs, 

 which are situated near the great Geysir and the Strokr, one bears the name of 

 " the Little Geysir." Its column of water rises only from 20 to 30 feet. Ac- 

 cording to an account of Esoma de Kerb's, there is a small Geysir, sending forth 

 a column of water about twelve feet high, in the high lauds of Thibet, near the 

 Alpine lake Mnpham. 



( 275 ) p. 201. There are of fixed constituents, in 1000 parts in the springs of 

 Gastein Tromrnsdorf only 0'303; in the Lb'wig, at Pfeffers, 0'291; and in the 

 Longchamp, at Luxeuil, 0'236 : while, on the other hand, in every 1000 parts 

 of the common spring water at Berne, there have been found 0'478 ; in the 

 Carlsbad Sprudel, 5'459; and in the Wiesbaden water even 7'454. Studer, 

 a Physikal. Geogr. und Geologic," 2nd edition, 1847, Cap. i. S. 92. 



( 278 ) p. 202. " Les eaux chaudes qui sourdent du granite de la cordillere du 

 littoral (de Venezuela) sont presque pures ; elles ne renferment qu'une petite 

 quantite' de silice en dissolution, et du gaz acide hydro-sulfurique mele' d'un peu 

 de gaz azote. Leur composition est identique avec celle qui resulterait de 1'ac- 

 tion de 1'eau sur le sulfure de silicium." (Annales de Chimie et de Phys. 

 t Hi. 1833, p. 189.) On the large quantity of azote in the hot spring of Orense 



