1156, 157, 158 | BORED AND ARTESIAN WELLS. 105 



none of the calcareous Tombigbee Sand or Rotten Limestone. It 

 is likely, therefore, that in most cases, the lime is imparted to these 

 waters'by standing in, or passing through, the calcareous strata 

 which overlie the water-bearing formation. 



156. In the bored wells in which the water is stationary, the 

 iron is usually contained as proto-carbonate, which is soon precep- 

 itated by the air, forming a dark brown scum or sediment on the 

 bucket. In some of the artesian wells, however (as in the case of 

 Gen. R. Davis', at Aberdeen), there is proto-sulphate of iron, pro- 

 ducing a yellowish brown sediment of basic persulphate. Perhaps 

 the iron is in most cases contained originally as proto-sulphate, 

 derived from the "sulphur balls" occurring in the dark-colored 

 clays, and is thereafter transformed into carbonate, and partially 

 precipitated, by the contact with the carbonate of lime. Some 

 waters derived from the Eutaw Group contain a large amount of 

 silica ; as for instance, that of Dr. Rabb's well at Columbus, which 

 incrusts tumblers immersed in it with a firmly adhering, brown 

 film. When the surface thus coated is heated with hydrochloric 

 acid, the iron is removed and a whitish film remains, which is 

 soluble in potash and insoluble in salt of phosphorus. 



The elevated portion of the strata which furnish the water of 

 the Columbus and Aberdeen wells, is doubtless to be sought in the 

 high ridges bordering on the Buttahatchie and Looxapalila ; 

 although these show on their surface, and sometimes at great depths, 

 nothing more than Orange Sand strata. 



Few wells are sunk in the Tombigbee Sands alone ; they have 

 very limy water. 



157. On the territory of the Rotten Limestone, little water is to 

 be found, unless in surface tanks, or by passing through the whole 

 stratum, into the Tombigbee Sand, or Eutaw Group. Locally, 

 however, small water-bearing strata have occasionally been struck 

 within the Rotten Limestone. Thus at Okalona, at 75 feet, water 

 excessively limy and with little rise, and insufficient in quantity, 

 was obtained. At Houston and Sparta, the same thing happens 

 (1122), the water at the latter place being in some cases a perfect 

 ley of gypsum and Epsom salt. For a supply of water in the 

 prairie region, therefore, the alternative generally lies between deep 

 bored wells and cisterns; unless indeed, as on Kilgore's Ridge, 

 there should be a mass of Orange Sand of sufficient thickness, 

 overlying the rock. 



158. On the territory of the Ripley Group, there is little diffi- 

 culty about water. In the first place, springs are abundant. Orange 

 Sand very commonly forms the higher portions of the ridges, while 

 the cretaceous marls underlie as an impervious statum ; finally, 

 good water (though somewhat limy) may frequently be struck in 

 the strata of the Ripley Group themselves. Such is the case in 

 Tippah, where the calcareous strata of the Ripley Group are passed 

 through at 40 to 70 feet, into water-bearing sand. So also, the 



