T. S. Hunt on the Chemistry of Natural Waters. 195 
sought for in a few instances, and was detected in the waters of 
Varennes. Most of these analyses were made before the discov- 
ery of the new metals cesium and rubidium. 
§ 54. Salts of Caleium and Magnesium.—We have to consider 
under this head the relations both of the chlorids and the car- 
bonates of these bases. The bitter saline waters of the first class, 
although containing large quantities of chlorids of calcium and 
magnesium, are, as we have seen, generally destitute of earthy 
B 
and magnesia which the waters of the fourth class hold in solu- ‘ 
tion, the carbonate of soda which they contain gives rise, by its - 
reaction with the chlorids of calcium and magnesium, to addi- : 
tional quantities of the carbonates of these bases. In the waters 
nate of lime and bicarbonate of magnesia co-exist. 
such a solution is submitted to evaporation at ordinary tempera- 
tures, provided there is present a sufficient amount of chlorid o: 
calcium, carbonate of lime alone is deposited, and chlorid of 
Magnesium remains in solution. 
n 
oy , Tepresents the carbo th 
- Of the Gicacipiinie at an earlier stage of the ebullition 
_ have farnished, ; ; oe 
Asan example of this may be cited the analysis of the water 
Of Ste. Genevieve (§ 42, No. 8), where the precipitate after 
few minutes’ boiling contained carbonates of lime and magne 
