HOT SPRINGS. 219 



e the purest, and such as hold in solution the smallest 

 quantity of mineral substances. Their temperature appears on 

 the whole to be less constant than that of springs between 122 

 and 165 which in Europe at least have maintained in a most 

 remarkable manner their invariability of heat and mineral con- 

 tents during the last fifty or sixty years a period in which 

 thermometrical measurements and chemical analyses have 

 been applied with increased exactness. Boussingault found in 

 1823, that the thermal springs of Las Trincheras had risen 12 

 during the tw r enty-three years that had intervened since my 

 travels in 1800.* This calmly-flowing spring is therefore 

 now nearly 12 hotter than the intermittent fountains of the 

 Geyser and the Strokr, whose temperature has recently been 

 most carefully determined by Krug of Nidda. A very strik- 

 ing proof of the origin of hot springs by the sinking of cold 

 meteoric water into the earth, and by its contact with a volcanic 

 focus, is afforded by the volcano of Jorullo in Mexico, which 

 was unknown before my American journey. When in Sep- 

 tember, 1759, Jorullo was suddenly elevated into a mountain 

 1183 feet above the level of the surrounding plain, two small 

 rivers, the Rio de Cuitimba and Rio de San Pedro, disappeared, 

 and some time afterwards burst forth again, during violent 

 shocks of an earthquake, as hot springs, whose temperature I 

 found in 1803 to be 186'4. 



The springs in Greece still evidently flow at the same places 

 as in the times of Hellenic antiquity. The spring of Erasinos, 

 two hours' journey to the south of Argos, on the declivity of 

 Chaon, is mentioned by Herodotus. At Delphi we still see 

 Cassotis (now the springs of St. Nicholas) rising south of the 

 Lesche, and flowing beneath the Temple of Apollo ; Castalia, 

 at the foot of Pheedriadse ; Pirene, near Aero-Corinth; and 

 the hot baths of JSdipsus, in Euboea, in which Sulla bathed 

 during the Mithridatic war.f I advert with pleasure to these 



* Boussingault, in the Annales de Cliimie, t. lii. p. 181. The spring 

 of Chaudes Aigues, in Auvergne, is only 176. It is also to be observed, 

 that whilst the Aguas Calientes de las Trincheras, south of Porto 

 Cabello (Venezuela), springing from granite cleft in regular beds, and 

 far from all volcanoes, have a temperature of fully 206'6, all the springs 

 which rise in the vicinity of still active volcanoes (Pasto, Cotopaxi, and 

 Tunguragua) have a temperature of only 97-130. 



t Cassotis (the spring of St. Nicholas) and Castalia, at the Phsedriadae, 

 mentioned in Pausanias, x. 24, 25, and x. 8, 9; Pirene (Aero- Corinth), 



