Von Nidda on the Mineral Springs of Iceland. 



credible violence, and produces a roaring noise, which, at the 

 distance of a mile, resembles the dull sound of a lofty waterfall. 

 When stones are thrown into the opening, they are immediately 

 projected to a considerable height. 



The Sneefield-Syssel forms a long narrow tongue of land, 

 which stretches far out into the sea, on the west coast of the island. 

 Its geognostical constitution is similar to that of the promontory 

 of the Guldbringesyssel. In its centre there is a mountain chain 

 composed of tuffas and slag conglomerates. Numerous cones 

 of eruption are placed on the summit as well as at the base of 

 this ridge, and from them have issued considerable streams of 

 lava. Along the south coast of the tongue of land there is a 

 long line of mineral springs, that are completely different from 

 the greater number of the other mineral springs which are 

 dispersed over the trachytic region of Iceland. They have 

 a comparatively much lower temperature, are rich in carbonic 

 acid in a pure and combined state, and contain, especially, car- 

 bonates of soda and lime, together with the muriate and sul- 

 phate of soda. On the other hand, silica and sulphuretted 

 hydrogen occur only in extremely minute quantities. The in- 

 habitants of Iceland term the springs olkilder, that is, beer- 

 springs, owing to the somewhat intoxicating power communi- 

 cated to them by the quantity of carbonic acid they contain. 



Mackenzie * carried away water from several of these springs, 

 and sent it to Thomson for examination. The most remarkable 

 springs of the series are the following : 



Near Stadehraun there is. a spring which rises from a stream 

 of lava ; it is very rich in carbonic acid, and contains little else 

 but carbonate of lime. 



At Rudemelr there is situated, among the volcanic cones of 

 eruption, a mineral spring, whose temperature is 6 R. (45JF.), 

 which exhales much carbonic acid gas, and contains carbonate 

 of lime as a chief constituent ingredient. . 



The spring at Lisiehuls has a temperature of 28 R. (95 F.). 

 The carbonic acid gas which is evolved by it in great abundance, 

 is certainly mixed with a trace of sulphuretted hydrogen gas. 

 It contains in solution, carbonate of soda, carbonate of lime, 

 muriate of soda, and a trace of sulphate of soda. 



* Travels in Iceland, p. 398. 



