and on the Absorption of Gases by Water. 249 



KaiserqueUe, at Aachen, only nitrogen, carbonic acid gas, and 

 0.5 per cent, sulphuretted hydrogen. I found, however, 7 per 

 cent, oxygen. Monheim found in the Pockenbrilnncheii, at 

 Burtscheid, only nitrogen, carbonic acid gas, and 0.1 per cent, 

 sulphuretted hydrogen ; but, according to my analysis, oxygen' 

 exists in the proportion of 2 per cent. Monheim found that the 

 gas of the Trinhqiielle, at Burtscheid, has nearly the same com- 

 position as that of the Pochenbrunnchen. In the gas of tlie 

 Kochenbrunnen, and of the warmest of all the thermal springs 

 of Burtscheid, the saine observer found, besides the nitrogen^ 

 and carbonic acid gas, also 0.1 to 0.15 per cent, oxygen.* My 

 researches give, as the mean of three analyses, 47.3 carbonic 

 acid gas, 52.1 nitrogen, and 0.6 oxygen.-f Finally, Anglada 

 found that the gas evolved by the sulphureous springs of the 

 Pyrenees consists of pure nitrogen. ;J; 



3. ^Atmospheric water enters clefts which are filled with car- 

 bonic acid gas derived from peculiar processes in the interior of 

 the earth. In this case, which is one that occurs more especial- 

 ly in districts of extinct volcanoes, the gas is absorbed by water, 

 and acidulous springs are produced. 



Since carbonic acid gas is not only absorbed by water in much 

 larger quantity than atmospheric air, but also since, at a temper 

 rature of 0° R., it is liquefied by a pressure of 36 atmospheres, 

 it is evident that, under these circumstances, carbonic acid 

 can in every condition be taken up by water. Carbonic acid, 

 at a depth of 1152 feet beneath the earth''s surface, under the 

 pressure of a column of water of that height, could therefore ex- 

 ist only in a liquid form. Since, however, at such a depth, ac- 

 cording to the observations on record, a temperature prevails 



large portion of carbonic acid gas, in proportion to the nitrogen, can only to 

 a very small extent be derived from atmospheric air. Streams of carbonic 

 acid gas must therefore be added. 



* " Die Heilquellen von Aachen Burtscheid," &c. Aachen und Leipzig^ 

 1829, p. 209, 232, &c. 



-|- The remark I made in regard to the Kochbrunnen of Wiesbaden, is al- 

 so applicable here. 



X Memoires pour servir k I'Histoire G6nerale dea Eaux Min^rales Sul- 

 phureuses et des Eaux Th^rmales. Paris, 1828. And, Ann. de Chim. et de 

 Phys. torn. xx. p. 246. 



7 



