200 COSMOS. 



has acquired a high temperature at a lower point under great 

 pressure of accumulated vapours, being forced upwards, and 

 thus coming under a pressure which does not correspond 

 with its temperature. In this way " the Geysirs are natural 

 collectors of steam power." 



Of the hot springs a few approach nearly to absolute 

 purity others contain solutions of 8 12 parts of solid or 

 gaseous matters. Among the former are the baths of Lux- 

 eueil, Pfeffer, and Gastein, the efficacy of which may appear 

 so mysterious on account of their purity. 81 As all springs 

 are fed principally by meteoric water, they contain nitrogen, 

 as Boussingault has proved in the very pure 82 springs flowing 

 from the granite in las Trincheras de Portocabello, and Bun- 

 sen 63 in the Cornelius spring at Aix and in the Geysir of 

 Iceland. The organic matter dissolved in many springs also 

 contains nitrogen, and is even sometimes bituminous. Until 

 it was known from the experiments of Gay-Lussac and my- 

 self that rain and snow-water contain more oxygen than 

 the atmosphere (the former 10, and the latter at least 8 per 

 cent, more) it appeared very remarkable that a gaseous mix- 

 ture, rich in oxygen, could be evolved from, the springs of 

 Nocera in the Apennines. The analyses made by Gay-Lus- 

 sac during our stay at this mountain spring showed that it 

 only contained as much oxygen as might have been furnished 

 to it by atmospheric moisture. 54 If we be astonished at the 



51 Trommsdorf finds in the springs of Gastein only 0.303 of solid 

 constituents in 1000 parts; Lowig, 0.291 in Pfeffer; and Longchamp 

 only 0.236 in Luxeuil; on the other hand, 0.478 were found in 1000 

 parts of common well water in Berne ; 5.459 in the Carlsbad bubbling 

 spring; and even 7.454 in Wiesbaden (Studer, P/iysikal. Geographic und 

 Geologic, ed. 2, 1847, cap. i, s. 92). 



52 The hot springs which gush from the granite of the Cordillera of 

 the coast (of Venezuela), are nearly pure ; they only contain a small 

 quantity of silica in solution, and hydrosulphuric acid gas, mixed with 

 a little nitrogen. Their composition is identical with that which would 

 result from the action of water upon sulphuret of silicium" (Annales de 

 Chimieet de Physique, t. lii, 1833, p. 189). Upon the great quantity 

 of nitrogen which is contained in the hot spring of Orense (154.4), 

 see Maria Eubio, Tratado de las Fuentes Minerales de Espaiia, 1853, 

 p. 331. 



53 Sartorius von Waltershausen, Skizze von Island, s. 125. 



54 The distinguished chemist Morechini of Rome, had stated the 

 oxygen contained in the spring of Nocera (situated 2240 feet above the 

 snati to be 0.43 j Gay-Lnssac (26 September, 1805) found the exact 



