and on the Absorption of Gases by Water. 251 



the earth of the place by 2° or 4° R., have a remarkable con- 

 stancy in their temperature and the quantity of water. I have 

 made observations for several years on three springs, of which 

 one makes its appearance at about fifty paces from the others. 

 Durino- more than a year, I observed their temperature and 

 quantity of water at least once a month. Two of them abound 

 in carbonic acid, the third is a common spring. The maximum 

 of temperature of the two former is 11°,6 and 9°.5 R., the mini- 

 mum 11°.4 and 9°.3 R. ; the whole yearly difference therefore 

 only 0°.2 R. ; whereas the maximum of the common spring is 

 8°, the minimum 6°.4, the yearly difference therefore 1°.6 R. No 

 difference can be observed in the quantity of water given out by 

 the two mineral springs during the year, whereas the common 

 spring sometimes pours out more than twice as much as at 

 others. 



If we assume that the warmer of the two mineral springs is 

 produced by the mixture of warm water having a constant tem- 

 perature of 24°.4 R., with the warm common spring having a 

 temperature of 6°.4 to 8° R. ; then one part of water of 24°.4 

 must be mixed with three parts water of 6°.4 to 8°, in order to 

 maintain the temperature of 11°.4 to 11°.6. But, according to 

 this supposition, the temperature of that spring would vary 

 from 10°.9 to 12°.l, and there would thus be a yearly difference 

 of 1 °.2 ; whereas the real difference is only 0°.2. This difference 

 would be still greater if, as is actually almost the case, the 

 maximum of quantity of the common spring should be com- 

 bined with the minimum of temperature, and the reverse. 



From this simple observation, it appears that the mineral 

 spring of 11°.5 could not be produced by a mixture of water of 

 24°.4 with water which varies as that of the common spring. 

 According to what has been said, water of 24".4 R. must come 

 from a depth where carbonic acid would be liquid : thus, when 

 the matter is considered also in this point of view, the probabi- 

 lity is diminished that those acidulous springs whose temperature 

 exceeds by only a few degrees the mean temperature of the 

 place, can be produced by mixture with liquid carbonic acid. 



Under the ordinary pressure of the atmosphere, one measure 

 of water, according to Saussure, absorbs 1.07 carbonic acid gas; 

 under higher pressure we can increase this absorption to double 



