100 
GEOLOGY OF THE FIRST DISTRICT. 
depths and rises freely through crevices in the rock, is rendered probable from its alternately 
breaking out and disappearing at points somewhat distant to each other. And perhaps the 
opinion of Berthier may here be applied, namely, that the water of the spring is forced up 
by the elasticity of the confined gas. 
“ The phenomena presented at Ballston, so far at least as the evolution of carbonic acid is 
concerned, are quite analogous to those noticed by Brandes and Kruger in their account of 
the mineral waters of Piedmont; that the extrication of this gas is by no means limited to the 
spot from whence the chalybeate springs of that watering place arise, but is observed for some 
distance round, wherever fissures, natural or artificial, exist. Thus, a cavity having been 
made, by some workmen for quarrying stone, it was found that the air became charged with 
from thirty-six to forty-eight per cent of carbonic acid, which rose in the cavern to different 
heights at different times.* 
“ In general, the occurrence of carbonic acid in these waters is to be ascribed to the exist¬ 
ence of large quantities of it held in solution by water at great depths, and therefore under 
enormous pressure ; or by the gas itself being kept by the same agency in a liquid form, until 
by the removal of the pressure, it assumes the gaseous state, and is thus disengaged. 
“ It i-s very difficult to estimate with accuracy the proportion of carbonic acid which these 
waters contain, as they are continually pervaded by gas, which apparently has no action upon 
its constituents. Perhaps the best guide in this part of the investigation is to determine the 
amount of gas necessary to hold the solid carbonates in solution, as they undoubtedly exist in 
the state of bicarbonates. The following table will exhibit the composition of one of the 
Ballston waters: 
United States Spring. 
Specific gravity, 1.00611. Temperature, 50° F. One pint of the water contains, 
Carbonate of lime, with a small admixture of oxide 
of iron,. 3.65 grains. 
Carbonate of magnesia,. 0.72 “ 
Carbonate of soda,. 2.11 “ 
Sulphate of soda,. 0.22 “ 
Chloride of sodium,.53.12 “ 
Silica,t. 1.00 “ 
Carbonic acid, 30.50 cubic inches. 
60.82 grains. 
“ Low's well, recently restored, has a composition similar to the preceding, but the amount 
of saline matter is much less. Its specific gravity is 1.02548, temperature 50° F. 
* Quoted by Professor Daubeny in his Report on Mineral and Thermal Waters, p. 37. 
t “ This water probably contains both iodine and bromine; but the quantity upon which I operated was too small to admit of 
separating them, and determining their relative proportions.” 
