192 COSMOS. 



In this way " the Geysers 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- 

 euil, PfefFer, and Gastein, the efficacy of which may appear 

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

 are fed principally by meteoric water, they contain nitrogen, 

 as Boussingault has proved in the very puref springs flowing 

 from the granite in Las Trincheras de Porto Cabello, and 

 BunsenJ in the Cornelius spring at Aix and in the Geyser 

 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 myself, 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 gase- 

 ous mixture rich in oxygen could be evolved from the springs 

 of Nocera, in the Apennines. The analyses made by Gay- 

 Lussac during our stay at this mountain spring showed that 

 it only contained as much oxygen as might have been fur- 

 nished to it by atmospheric moisture.§ If^we be astonished 

 at the silicious deposits as a constructive material of which 



* Trommsdorf finds in the springs of Gastein only 0-303 of sohd 

 constituents in 1000 parts; Lovvig, 0-201 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 bub^ 

 bling spring ; and even 7-454 in Wiesbaden (Studer, Physikal. Geo- 

 graphie und Geologie, ed. 2, 1847, cap. i., s. 92). 



t "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 silicon" {An- 

 nates de Chimie et de Physique, t. Hi., 1833, p. 189). Upon the great 

 quantity of nitrogen which is contained in the hot spring of Orense 

 (154° -4), see Maria Rubio, Tratado de las Fuentes Minerales de Es- 

 2mna, 1853, p. 331. 



X Sartorius von Waltershausen, Shizze von Island, s. 125. 



§ The distinguished chemist Morechini, of Home, had stated the 

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

 the sea) to be 0-40; Gay-Lussac (26th September, 1805) found the 

 exact quantity of oxygen to be only 0-299. We had previously found 

 0-31 of oxygen in meteoric waters (rain). Upon the nitrogen gas con- 

 tained in the acid springs of Neris and Bourbon I'Archambault, see the 

 works of Anglade and Longchamp (1834); and on carbonic acid 

 exhalations in general, see Bischof 's admirable investigations in his 

 Chemische Geologie, bd. i., s. 243-350. 



