138 ECONOMICAL MINERALOGY. 



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 water at great depths, and therefore under enor- 

 mous 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.t Mr. Mather 

 suggests that the mineral qualities of the Ballston waters originate at the contact of the slate 

 with the Trenton limestone, which he thinks is not more than fifty feet below the level of the 

 valley. 



Washington County. Reed's Mineral Spring, in South Argyle, near the Moses Kill, 

 is an acidulous carbonated water, somewhat similar to the Saratoga waters, but it contains 

 less gas. According to Mr. Mather, some bubbles of carbonic acid rise from the water, the 

 taste of which is distinctly acidulous, but it does not sparkle.J 



Albany County. A spring similsir to those of Ballston and Saratoga, was discovered in 

 the city of Albany in 1827. Messrs. Boyd & McCuUoch, the proprietors of a brewery in 

 Ferry-street, in the hope of obtaining pure water on the premises, in sufficient quantity for 

 the supply of their establishment, commenced boring upon the plan of Mr. Disbrow, during 

 the year 1826. After descending to the depth of about four hundred and eighty feet, the 

 water, which rose nearly to the surface, was found to have a saline taste and a sparkling ap- 

 pearance. At the request of the proprietors, I analyzed a portion of this water, and found 

 its composition to be as stated below. There was also observed, rising through the water, an 

 inflammable gas, which was found to be carburetted hydrogen. The boring was continued 

 about six hundred feet through the slate rock, and the flow of carbonated water and inflam- 

 mable gas continued. The obtaining of fresh water being therefore considered hopeless, a 

 tube was sunk to prevent the admixture of the carburetted hydrogen with the mineral water, 

 and an apparatus constructed for raising a supply of the latter. 



Subsequently, Mr. McCulloch commenced boring a few rods from this place, when, at about 

 the same depth, the vein of mineral water was again struck. It was also accompanied by 

 the inflammable gas, as in the former case. And to add to the interest of the locality, it was, 

 moreover, found that at the depth of about thirty feet from the surface, a vein of water was 

 crossed which was highly charged with sulphuretted hydrogen gas. We have then in the same 

 slate formation, though at different depths, sulphuretted hydrogen, carburetted hydrogen and 

 carbonic acid gases, abundantly evolved. 



 See Professor Daubeny*s Rejxrrt on Mineral and Thermal Waters. 



t Biscbof concludes a paper on tlie " Subterranean course of water, etc." with the following remarks : " In order then to explain 

 the absorption of carbonic acid gas by the water, and the subsequent decomposition of the component parts of this carbonic-acid, 

 water, to explain in one word the formation of a mineral spring, rich in carbonic acid, we have only to assume, that in the interior 

 of the earth, naiTow canals coming from beneath, join large ones ; that they bring carlionic acid gas, and that the larger canals are 

 filled with water." Edinburgh New Philosophical Journal, XVIII. 246. 



J New-York Geological Reports, 1841. 



