228 ACTION OF SOME OF THE ALKALINE SALTS. 



feebler acids and stronger bases; they dissolve the sulphate, 

 thus affording an opportunity for the acids and bases to act 

 upon one another under favorable circumstances, and to follow 

 a natural law in chemistry: the stronger acid combined with 

 the stronger bases, and vice versa. 



From the foregoing facts some important hints might be 

 afforded to analytical chemistry, for it will be at once seen that 

 the presence of any of the alkaline salts in a solution from 

 which it might be wished to precipitate lead in the form of a 

 sulphate would affect the accuracy of the result. What is true 

 of the sulphate of lead may be found also true for other in- 

 soluble salts. Moreover, this. shows the importance — in the 

 .analysis of mineral waters, for instance — of weighing well the 

 relative strength of the various acids and bases therein found, 

 in order to ascertain what salts are present, and not to be con- 

 tented with evaporating the water to dryness, and considering 

 such salts as remain to be those existing in the water, for many 

 of them may be formed during the evaporation. It is not at 

 all improbable that before many years the examination of min- 

 eral waters will be based as much upon calculation as upon 

 analysis, the former of course being guided by the latter and 

 by certain laws not yet developed. 



