70 HOME LIFE IN FLORIDA. 



with magnesia and carbonate of lime ; the one is perma- 

 nently hard and utterly intractable, crying out, " The more 

 you try me the more I won't come — soft ;" the other is 

 more obedient and only temporarily hard. But under- 

 stand when we say ' ' temporarily " we do not mean that the 

 character of the water in the well itself is subject to change, 

 that it fluctuates, and is sometimes hard and sometimes soft ; 

 not this at all, but only that by certain processes the hard- 

 ness may be removed and the water rendered as soft as rain- 

 water. Of course there is a reason for this. The sulphate 

 of lime contained in the permanently hard water is deserted 

 by it and becomes one of its constituents, and then when 

 you rub soap in it the stearic acid in the latter combines 

 with the lime and magnesia and forms a chemical comj)ound 

 that the water can not dissolve, and so instead of a pleasant 

 cleaning lather, an ugly, disagreeable curdiness results. 



On the other hand, the carbonate of lime, which is 

 found in the temporarily hard water, is not, and can 

 not be dissolved, like the sulphate, by pure water, and 

 hence it is only held in suspension, not permeating or 

 becoming an inseparable constituent of the water. 



How does the carbonate get there, then, you ask ? The 

 explanation is simple; all natural waters, but especially 

 those obtained from wells or springs, contain more or less 

 carbonic-acid gas in a state of absorption, and when thus 

 charged are capable of dissolving the carbonates. 



Thus we see that, while pure water will not dissolve the 

 carbonates, water that contains a certain proportion of 

 carbonic-acid gas will do so. But expel the latter gas, 

 and the carbonate will be at once precipitated. This ex- 

 pulsion is easily accomplished by boiling, and the incrus- 

 tation found at the bottom and sides of the kettle show^s 

 what has become of the carbonate. Try the water now, 

 and you will find it soft and fit for any purpose. 



