﻿82 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Dec. 18, 



If any geologist should observe, upon any one given line, different 

 mineral springs, holding the same salts in solution, as well as im- 

 pregnated with the same gas, he would naturally infer (particularly 

 if they were hot-springs) that they issued from a deep crack in the 

 subjacent crust of the globe. This presumption is, I think, con- 

 verted into a certainty in the case of Vichy, by the coincidence of 

 the upcast of the rocks of the Celestins with this line of thermal 

 springs. So far all seems to be a legitimate deduction from facts. 

 But if I am asked, how is it that along the same line of fissure the 

 water of the Celestins, so copiously charged with carbonate of soda 

 and carbonic acid, should be cold, and that the other springs con- 

 taining those substances are hot ? and why the respective tempera- 

 tures of the warm sources should so vary ? — the answers must be 

 hypothetical. 



The view of Daubeny and other chemical geologists is that the 

 carbonate of soda, which impregnates mineral waters, is attributable 

 to the action of the carbonic acid they contain upon the felspar of 

 some subjacent rock. In this tract it is very probable that large 

 masses of felspathose rocks (such as the adjacent porphyries of Cusset 

 and the Sichon) lie beneath the tuffs and limestones of Vichy, and 

 really furnish the soda*. 



But whatever may be the subterranean source whence the mineral 

 ingredients of these waters may be derived — whether from compa- 

 ratively moderate depths only in the crust or otherwise, there can be 

 little doubt that their lower or higher temperature is dependent on 

 the aperture beneath each being less or more in connection with a 

 great internal source of heat. Thus, I would infer, that beneath the 



tains three times the quantity of carbonate of soda detected in the Carlsbad waters 

 by Berzelius, and nearly twice as much as the most alkaline water of Germany, 

 at Fachingen, analysed by Bischoff. That such a water should have most powerful 

 salutary effects, in many disorders, is not therefore to be wondered at. At the 

 Grande Grille, the ingredients (differing only slightly from the other sources) 



are as follows : — 



Carbonate of soda 21-9058 



Carbonate of ammonia 0*0277 



Carbonate of strontia 0*0134 



Carbonate of lime 0*1441 



Carbonate of magnesia 0*2036 



Carbonate (proto) of manganese 0028 



Carbonate (proto) of iron 0*0072 



Subphosphate of lime , . 0*0026 



Subphosphate of magnesia 0*0189 



Sulphate of potass 1*1760 



Sulphate of soda 0*6780 



Chloride of sodium 3 3338 



Bromide of sodium 0*0007 



Iodide of sodium 0*0002 



Alumina 0*0049 



Silica 0*3696 



Solid contents. Total 29*1893 



Carbonic acid gas in 100 cubic inches 97. 



Temperature (Fahr.) 107°. 

 * See Report on Mineral Springs, British Association for the Advancement of 

 Science, 1836, vol. v. p. 20 et seq. 



