4 



114 Gypsum. — Muritiferous Strata. 



Stone and coal, deep In the earth throughout the whole valley. It 

 is seen in great abundance along the southern shore of lake Erie, 

 near Sandusky, and in various other intermediate places, quite to the 

 borders of New York and in the interior^ of that state, being found 

 at intervals from the shore of the lake, to the mountain ranges. At 

 the salt works, on the heads of the Holstein, it is discovered in great 

 abundance, appearing partly to encircle the salt region with a cordon 

 of deposits. From the fact, that no muriate of lime, or magnesia, 

 enters into the composition of native rock salt^ it being a pure mu- 

 riate of soda, wherever discovered in other parts of the earth, I am 

 led to conclude that the brine springs in the valley of the Ohio, are 

 not supplied from a deposit of rock salt, but from salt in small grains 

 and particles, pretty equally diffused through the lower strata of 

 rocks and marls, wherever the salt springs abound. The notorious 

 fact, that the brine becomes weaker in a well worked very con- 

 stantly, and the necessity of boring deeper to renew the strength of 

 the water, goes to confirm this opinion, especially on the Kenawha; 

 whereas, if the water was supplied from a deposit of pure solid salt, 

 the well would remain of uniform strength. Another proof is found 

 in the fact, that the deeper wells are supplied with a stronger wa- 

 ter, showing that the further the saline strata are penetrated the 

 more certain they are to supply a strong brine. The nearer satura- 

 ted, the more heavy the water becomes, and It settles to the deeper 

 cavities. The water which holds the salt in solution, being supplied 

 by the river above, percolates gradually through the crevices and 

 openings in the different rocks, dissolving the saline particles as it 

 descends, in the same manner that water dissolves the particles of 

 * potash in wood ashes : the lixivium at the bottom of the leaching 

 tub, being much stronger than that near the top, or half way down. 

 The principal salt works in " the valley," are uniformly found on 

 large water courses ; wells sunk on small creeks, always affording a 

 weak brine, or a very scanty supply of water. The vicinity of some 

 large stream is therefore necessary to bring the salt w^ater to the 

 surface of the earth ; the water in the wells uniformly rising, as the 

 water rises or falls in the river, showing an intimate connexion be- 

 tween the waters below, and those in the stream above. The 

 strongest water and most abundant supply, are furnished by a stratum 

 of fine grained, white sandstone, at nearly all the works of any ce- 

 lebrity; and although naturally of a compact structure, cavities of 



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