No. 200.] 
51 
the Franklin sulphur spring. Thus there are three springs, differing 
considerably in their chemical composition, rising within a few feet of 
each other. The United States spring is highly charged with carbonic 
acid gas, while the others contain only a small portion of it. 
From several of the springs at Ballston, there is a discharge of gas 
in smaller or larger bubbles, which does not unite with the water. At 
the Park spring in rear of the Village Hotel, minute portions of gas are 
continually rising through the water, but at an interval of a minute the 
whole well is agitated by the evolution of a comparatively large bulk 
of the gas. This gas, which in all cases is the carbonic acid, also rises 
in great abundance through the water of a well near Low's spring and 
in various places in the valley of the stream. A few years since there 
was a very remarkable and indeed almost volcanic discharge of it near 
the old factory, which threw up the water of the creek several feet into 
the air, but the gas soon diminished greatly in quantity, and can now 
be observed rising only in small bubbles through the bed of the stream. 
From these facts it is evident that here, as at Saratoga, there are cer- 
tain agencies in operation which cause an abundant evolution of carbo- 
nic acid. That this gas originates at great 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, viz. that the wa- 
ter 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 Pyrmont, 
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 ob- 
served for some distance round, wherever fissures, natural or artificial, 
exist. Thus, a cavity having been made by some workmen for quar- 
rying 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 existence of large quantities of it held in solution by wa- 
ter 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 
* Quoted by Professor Daubeny in his Report on Mineral and Thermal waters, p. 37. 
