"tla acy 
184 7. S. Hunt on the Chemistry of Natural Waters 
The above data might be much more extended, but sufficient 
have been given to show the porosity of the principal Paleozie 
rocks of the basin.* we 
- $16. If we take from the Potsdam sandstone the mean of the 
first three trials, giving 2°50 per cent for the volume of water 
which it is capable of holding in its pores, we find that a thickness” 
of 100 feet of it would contain in every square mile, in round pum 
bers, 76,000,000 cubic feet of water; an amount which would 
supply a cubic foot (over seven gallons) a minute for more than 
thirteen years. The observed thickness of the Potsdam sand 
gradually replace these saline waters, which ina mix and | 
ted state appear as mineral springs. These saline solutions 
$17. But besides the saline matters thus disseminated in# 
dissolved state in ordinary sedimentary rocks, there are ae 
volumes of saliferous strata, properly so-called, charged bigot 
results of the evaporation of ancient sea-basins. “ng 
enclose not only gypsum and rock-salt, but in some 
large quantities of the double chlorid of potassium te 
Slum, -carnallite; and in others sulphate of soda, supe 
magnesia, and complex sulphates like blddite and polynanie 
Besides these crystalline salts, the mother-liquors containing” 
* A great many similar determinations will be found in 4 a bo 
Stones Ve teb falter : “by Barry, Dela Beche and * 
See also Delese. Bull. Soe. Geol 2] ois 64 
