46 Mr. H. Holland on the Cheshire Rock-salt District. 



by several layers of indurated clay or argillaceous stone. These 

 intervening beds possess in conjunction a very uniform thickness of 

 ten or eleven yards, and are irregularly penetrated by veins of the 

 fossil salt. Though the evidence on the subject is not entirely of a 

 positive nature, there seem strong grounds for believing that the beds 

 of rock-salt at Northwich are perfectly distinct from any others in 

 the salt district, forming vsrhat the Germans would call liegende stocke, 

 lying bodies or masses of the mineral. It will readily be conceived 

 that there is much difficulty in acquiring precise information with 

 respect to the extent and limitation of these great masses, and that 

 there are many sources of error to which such an inquiry is liable. 

 There are, however, a few leading facts upon which dependence 

 may be placed, and which will be admitted to furnish fair grounds 

 for deduction. 



It would appear that the great beds of rock-salt at Northwich 

 assume a general longitudinal direction from north-east to south- 

 west, the line which has been traced upon them in this direction 

 being a mile and a half in length, and no direct evidence existing 

 that they may not extend further in these points ; while their trans- 

 verse extent, as measured by a line at right angles to the former, is 

 much more limited, probably not exceeding in any place one thou- 

 sand three hundred or one thousand four hundred yards. Several 

 circumstances concur in giving probability to this statement. Let 

 two parallel lines, drawn from NE to SW, with an intervening 

 distance equal to about half their length, be employed to designate 

 the supposed extent of the subjacent rock-salt. In a mine which 

 approaches very nearly to the eastern limit of the area thus formed, 

 the upper bed of rock-salt was actually worked through in an hori- 

 zontal direction on this side, and discovered to be going off with a 

 very rapid declivity. A similar fact has been stated with respect to 



