248 M. Bischof on the Subterranean Course of Water, 



er proportion of oxygen than is contained in atmospheric air, 

 and, indeed, sometimes consisted entirely of nitrogen.* This it 

 is easy to understand, when we consider that, by the oxidation 

 of various substances partly inorganic (carbonate of iron, liver 

 of sulphur, &c.), partly organic (organic remains, acids of 

 springs-f-), &c., which the water, containing a quantity of atmo- 

 spheric air, meets during its course, that oxygen may be lost. 

 In this manner, when carbonaceous organic substances are oxi- 

 dyzed, carbonic acid is produced, which, on account of the faci- 

 lity with which it is absorbed, will be retained, and renders the 

 water an agreeable beverage. If the circumstances we have 

 mentioned remained the same, the enclosed air at I could be gra- 

 dually entirely absorbed by the water. But when, in dry sea- 

 sons, the atmospheric water is not sufficient to fill the canal b c, 

 new atmospheric air enters the hollow c from above, and after- 

 wards, when the canal 6 c is filled in a wet season, is again gra- 

 dually absorbed by the water, and so on. 



When atmospheric water penetrates to a great depth, and 

 there acquires a higher temperature, it loses the power of re- 

 taining the air absorbed at the ordinary temperature and under 

 the usual pressure, and, on this account, it gives it off when ir. 

 comes to the surface. Hence the frequent phenomenon of the 

 disengagement of air from hot springs, as, for example, at Aachen, 

 Burtscheid, Wiesbaden ; from the warm Paderqiiellen at Pader- 

 born, &c. A circumstance, well worthy of attention, is in fa- 

 vour of this view, viz. that the last mentioned springs disengage 

 more gas the warmer they are.j 



Conformably to the views already given, the air disengaged 

 by warm springs will contain less oxygen than atmospheric air 

 does, and often only nitrogen with or without carbonic acid gas, 

 for the higher the temperature of the water, so much the easier 

 is the oxidation of the substances capable of oxidation. Thus, 

 L. Gmelin and Lade found that the gas evolved by the Koch- 

 brunnen, at Wiesbaden, consists of 82.3 carbonic acid gas, and 

 17.7 nitrogen.§ Monheim found in the gas evolved by the 



• Neues Jahrb. der Chemie und Phys. 1833, part xiii. p. 257. 

 t Annalen der Phys. und Chemie, vol. xxix. p. 3. and p. 238. 



* See my paper, p. 265. 



§ Annalen der Physik und Chemie, vol. vii. p. 467- It is clear that the 



