SALSES. 207 



and metamorphic transformation of rocks, the greater im- 

 portance has been acquired for the consideration of the 

 waters impregnated with gases and salts which circulate in the 

 interior of the earth, and which, when they burst forth at the 

 surface as thermal springs, have already fulfilled the greater 

 part of their formative, alterative, or destructive activity. 



c. Vapour and Gas Springs, Salses, Mud-volcanoes, 

 Naphtha-fire. 



(Amplification of the Picture of Nature. Cosmos, 

 vol. i. pp. 221223). 



In the General Representation of Nature, I have shown by 

 well ascertained examples, which, however, have not been 

 sufficiently taken into consideration, how the salses in the 

 various stages through which they pass, from the first erup- 

 tions accompanied by flames, to the subsequent condition of 

 simple eruptions of mud, form as it were an intermediate 

 step between hot springs and true volcanoes, which throw 

 out fused earths, either in the form of disconnected cinders, 

 or as newly formed rocks, often arranged in many beds one 

 over the other. Like all transitions and intermediate steps 

 both in organic and inorganic nature, the salses and mud- 

 volcanoes deserve a more careful consideration than was 

 bestowed upon them by the older geognosists, from the want 

 of special knowledge of the facts. 



The salses and naphtha springs are sometimes arranged in 

 isolated close groups : like the Macalubi, near Girgenti, in 

 Sicily, which were mentioned even by Solinus, those nearPietra 

 Mala, Barigazzo, and on the Monte Zibio, not far from Sas- 

 suolo in the north of Italy, or those near Turbaco in South 

 America ; sometimes they appear to be arranged in narrow 

 chains, and these are the most instructive and important. 



cold springs is, therefore, as follows : They are too cold for the eleva- 

 tion at which they come forth ; or, which indicates the conditions better, 

 they come forth at too low a part of the mountain for their low tem- 

 perature." These views, which are developed in the first volume of 

 Hallmann's Temperaturvcrhaltnissen der Quellen, have been modified by 

 the author in his second volume (s. 181 183), because in every 

 meteorological spring, however superficial it may be there must bo 

 some telluric heat. 



