46 Mr. West on Natural Waters. 



domestic purposes, with the single exception of water used 

 unmixed as a beverage. The gases do not appear to interfere 

 with the solvent properties of water, at least while cold, and 

 when heated they are quickly disengaged. 



The changes which take place as to the gases, when brisk 

 pump water is exposed in open vessels, are rather curious. I 

 found that water yielding twenty-six cubic inches, viz., ten 

 carbonic acid, and sixteen azote, &c., when fresh drawn, gave, 

 after standing five hours, twenty-five inches ; the diminution 

 was in the azote, the carbonic acid remaining the same. At 

 the end of nine hours, the total gases, twenty-two inches, one- 

 fourth of the azote had escaped, but very little, not two per 

 cent., of the carbonic acid. After three days, however, the 

 case was different ; no further escape of azote had taken place, 

 the water yielded about fifteen inches per gallon, and of this 

 only from one and a half to two consisted of carbonic acid. 

 The quantity of this gas was smaller than in river or pond 

 water. If these experiments, which I have not had time to 

 repeat, are tolerably correct, they would shew that, on expo- 

 sure to the atmosphere, the azote and oxygen contained in 

 water very soon begin to separate from it ; that after a time 

 the carbonic acid partially escapes, the other gases remaining ; 

 and that this continues until very little carbonic acid is left. 

 The power of water to retain gases in solution depends, the 

 temperature and pressure remaining the same, on the affinity 

 of water for the gas, and upon the proportion of that gas in 

 the superincumbent atmosphere. Those having a great affinity 

 for water fly off in some degree when the gases above the 

 water are wholly different, and those least readily absorbed are 

 retained under an atmosphere of the same gas. Now, these 

 two are antagonist principles in the case before us, azote having 

 little affinity for water, but constituting four-fifths of the sur- 

 rounding common air ; carbonic acid being much more abun- 

 dantly absorbed, but having no atmosphere of its own desscip- 

 tion to press on the water containing it. No calculation could 

 enable us, I think, to ascertain beforehand the order and the 

 degree in which these effects would take place ; that is, to pre- 

 dict the result of these experiments. 



