158 ON THE WATER IN THE CHALK 



AUTHORITY. 



A, Water from Chalk, not covered 



by overlying strata, at Watford Campbell (Watts, D.of Chemistry, p. 1016) 



B. Water from Chalk beneath the 



C 



The following points are especially noteworthy : — 



I. — That in A, fully four-fifths of the solids are chalk, the 

 remainder being made up of sulphates, chlorides, and nitrates of 

 calcium or sodium. 



2. — That in B, as compared with A — 



a. The total solid contents are more than double those in A 

 (in almost all cases), and in some more than treble. 



Ik — The amount of calcium is reduced to a fraction, between 

 one-third and one-eighth, of that in A. 



c. — Magnesium appears to an inconsiderable amount. 



d. — Sodium is enormously increased, and considerable quanti- 

 ties of potassium are found in several cases. 



e. — Carbonic acid is in general somewhat increased, but in 

 some instances diminished. 



/ — Sulphuric acid and chlorine appear in considerable quanti- 

 ties. 



This appears to indicate a substitution of soda for lime to a 

 very large extent, and this substitution explains the loss of hard- 

 ness in the water. Water which is hard owing to its containing 



