Hoi and Thermal Springs. S49 



where with the effect of a cause supposed everywhere to exist; 

 as ihcrnial springs are in some places very abundant, whilst in 

 others they are totally wanting. 



It is evident that Anglada only took those commonly called 

 hot springs into consideration. But since thermal springs are 

 so universally distributed over the earth, that which he opposes 

 to our hypothesis, argues, on the contrary, in its favour. 



Perhaps, he says, the phenomenon of thermal springs may be 

 best accounted for by the action of electromotors (electro-mo- 

 teurs), existing in the interior of the earth. Many German 

 philosophers are also known to have inclined formerly to this 

 hypothesis; but the greater part, at least those whose object is 

 not merely speculation but research, have now abandoned it.* 

 It may, however, perhaps, not be quite superfluous briefly to 

 examine the grounds which Anglada, a philosopher to whom we 

 are indebted for so many and such profound researches on mi- 

 neral waters, brings forward in support of such an hypothesis. 



According to him, there are many appearances on the surface 

 of the earth which indicate the existence of electromoters. As, 

 for instance, the Heideberg in the Fichtel-Gebirge, which Von 

 Humboldt discovered in the year 1796 to be polar magnetic.-|* 

 But by more recent inquiries, I have endeavoured to shew that 

 that polarity is only a consequence of the magnetic pyrites con- 

 tained in the rock. J If, as Anglada supposes, there exist an 

 electromolric power corresponding with the magnetic polarity, 

 and if the former is the cause of the heat of thermal waters, 

 then springs rising in the vicinity of lodes or beds of magnetic 

 iron-ore (oxydulatid iron) must always have an elevated tem- 

 perature. But this is by no means the case ; for example, in 

 Sweden, Siegen, and the Duchy of Westphalia, where consider- 

 able lodes and beds of that mineral are found. 



Anglada is of opinion, that although the constant running and 

 the uniform temperature of warm springs agree very well with 



• See Bischof, die Vulkanischen Mineralquellen, &c. p. 321 and following. 

 Perhaps I have the merit of having assisted in the downfall of this singular 

 hypothesis. 



+ See Gren's Neues Journ. vol. iv. part 1, p. 13G; and Von Huwboldt's 

 subseqient len.arks in the Ann. 1. de C him. et d.^ Phvs. vol. xxr. p. 327. 



X Gddfuss and Bischof Phys,kal-S:atisthe Beschriibung des Fichtelge- 

 birgtF, 111 7, part 1, p. 193, and following. 



