ONONDAGA-SALT GROUP. 163 



for this reason, the name is quite appropriate. Tlic quality of the water which has perco- 

 lated through these strata differs according to the depth it has penetrated, and the place 

 from which it has its exit. Those springs which issue just beneath the Waterlime series, 

 and above the green shaly mass, furnish very good water to drink. So the wells that 

 receive the water which has only percolated througii the same strata, furnish very good 

 drinkable water, though it is never soft, or free from the sulphate and chloride of lime. 

 Again, those springs which issue from the green shales, and whose waters have not pene- 

 trated through the plaster beds and the masses in which the hopper-form cavities occur, are 

 medicinal waters, or springs similar in composition to the Sharon springs. Of these 

 springs, a great many are found issuing from tlie northern outcrop of these rocks, and 

 they extend from the Helderberg to Buffalo nearly in a line. But the most important 

 are the brine and acid springs, and the salt wells : these issue, and derive their waters, 

 from the inferior mass. The saline as well as the acid matters are derived from the rock, 

 or the rock furnishes all the elements from which they are spontaneously formed by active 

 chemical changes, or decomposition and recomposition. Wherever the sulphurets of iron 

 abound, they give origin to the acid astringent salts. Tlie vegetable matter about these 

 springs is charred, and intermixed largely with the soil and with oxide of iron, so as to 

 forms mounds four or five feet high around them. The hepatic or sulphur springs derive 

 their properties, also, from the decomposing sulphurets. The sulphur is often deposited 

 upon leaves, sticks and stones, over which the water flows, and which is sometimes white 

 and sometimes bluish black. 



Another class of waters, differing from the preceding, may be termed, from their com- 

 position, lime waters. They are perfectly transparent, and flow usually in the greatest 

 amount from the inferior or middle strata. They have given origin to the numberless 

 beds of tufa which occur on a level, or else below the terrace that skirts the south side of 

 the Erie canal. These waters, though cool, are unfit for use. 



Wherever the Manlius waterlimes form the surface rocks, however great the area, no 

 springs or wells can be obtained in them, except at their base, or at the beginning of the 

 green shales, which, being comparatively impervious, throw out the surface water when 

 it reaches them. Thus at Manlius centre, there is a hill near the village, and directly 

 north, which has probably four square miles of surface, in which no water can be obtained 

 by digging, until the base is reached. From this base, many active and living springs 

 issue, which in the aggregate furnish sufficient water for several streams each large enough 

 to turn a mill, and indeed several mills are moved by the water direct from these springs. 



The brine springs and salt wells, without doubt, come from the deepest part of this forma- 

 tion. They may be obtained at almost any point, by sinking a deep well, upon the Onon- 

 daga reservation. A singular fact, and which at first view seems to militate against the 

 opinion that the saline waters are derived from this rock, is that the best wells are sunk 

 entirely in the drift, some of which penetrate three hundred and fifty feet. In those in- 

 stances where the rock is not penetrated at all, it appears that the salt water was originally 



21* 



