128 ECONOMICAL MINERALOGY. 



GAS OR CARBURETTED HYDROGEN SPRINGS. 



One of the most interesting facts connected with the history of mineral springs is, that some 

 of them constantly give out an inflammable gas, which on examination proves to be carburetted 

 hydrogen, often in a state of great purity, but occasionally mixed with small portions of other 

 gaseous bodies. This gas is also sometimes observed to issue from clefts in rocks, and from 

 water of ordinary purity ; and the close resemblance of its flame to that of coal gas, seems at 

 first sight to warrant the conclusion that it has its origin in the decomposition of coal ; but 

 this, however, is far from being in every case the true theory of its formation. 



Carburetted hydrogen may be distinguished from sulphuretted hydrogen, the gas which 

 characterizes what are called sulphureous or sulphuretted springs, by its not possessing that 

 offensive odour, and by its not producing those changes in metallic solutions, which are such 

 marked properties of the latter gas. 



Carburetted hydrogen may sometimes be obtained, mixed, however, with small portions of 

 carbonic acid and nitrogen gases, by agitating the bottom of a stagnant pool, especially if it is 

 formed of clay. Its production imder such circumstances is usually ascribed to the decom- 

 position of vegetable matter ; but this explanation is in some cases quite unsatisfactory. 



A locality of this kind just noticed occurs in the town of Northeast, in the County of 

 Dutchess ; where, from the bottom of a small lake, proceeds inflammable gas of considerable 

 purity. A short distance from Ameniaville, in this county, the same gas rises from the bed 

 of a small stream. 



In New-Lebanon, in the County of Columbia, one or two similar springs have been ob- 

 served. 



Albany County. Inflammable gas is quite abundantly evolved through a boring made 

 into the slate in the southern part of the city of Albany. Here it appears to be associated 

 with the carbonated water, to be hereafter noticed. Sulphuretted hydrogen also issues from 

 the same boring, but its source is much nearer the surface than that of either of the other 

 gases. That these gases are not connected with each other, and proceed from different layers 

 of the rock, is proved by the fact, that upon sinking down a tube, the mineral water is obtained 

 uncontaminated with either of these substances. 



The gas which issues from the Albany spring bums with a white flame tinged with red ; 

 and at length, when the flow of gas is temporarily impeded, the flame is of a blue colour, 

 owing probably to the imperfect combustion. When a current of the gas is made to pass 

 through a solution of acetate of lead, no change of colour ensues ; hence it cannot be mixed 

 with sulphuretted hydrogen. 



Oneida County. Carburetted hydrogen gas issues through a crag or gravelly soil about 

 a mile west of the village of Vernon, in this county. According to Prof. Eaton, who made 

 several trials in July, 1823, it issues through a spring of water at the rate of a gallon in a 

 minute. He states that he observed it "issuing from several small masses of water along the 

 foot of the same hill ; wiiich naturally induced a belief that it rises from the earth in all parts 



