^i? 



ON THE SALT SPRINGS OF WORCESTERSHIRE, 



It may be observed that the beds of rock-salt are of immense 

 thickness, and in this particular they bear a striking resem- 

 blance to those of Cheshire ; they also resemble those in 

 the varying degree of purity in which the mineral salt is 

 met with. Some of these beds contain as much as twenty- 

 five per cent, of marl, intermixed in small masses with the 

 pure salt, whilst the proportion in other beds does not exceed 

 seven or eight per cent. The veins of salt occurring in the beds 

 Nos. 3 and 5, afford beautiful specimens of this mineral, the very 

 small quantity of marl contained, being only sufficient to commu- 

 nicate a slight tinge of red, which rather adds to the beauty of 

 their appearance. The proprietors of this rock-salt mine con- 

 tinued to excavate the solid mineral for a considerable period, 

 and then, endeavouring to copy the operations of nature, they 

 introduced a supply of fresh water, and converted their mine into 

 an artificial brine spring. The dissolution of the mineral in 

 water, was at first effected in large reservoirs after it had been 

 drawn from the pit; but after the introduction of water, they 

 were enabled to obtain a supply of brine by means of pump- 

 ing, instead of having recourse to the much more expensive 

 operation of excavating the solid beds of salt. After continuing 

 this method of working for some months, a communication took 

 place between the natural brine spring and the mine, which ren- 

 dered the further introduction of water unnecessary. 



It is most probable that all natural brine springs are produced 

 by fresh water coming in contact with beds of rock-salt, and in 

 this way becoming charged with saline matter. This notion is 

 strengthened by the facts observed during the operations of 

 sinking a salt pit. In Cheshire, where these pits have been 

 excavated most extensively, it is quite uncertain, at commencing, 

 whether the product obtained will be dry rock-salt or native 

 brine ; but it has been observed that where the latter is met with, 

 it invariably occurs just before arriving at the rock-salt, and im- 

 mediately on the surface of the first bed of this mineral. It has 

 also been remarked in the operation of boring which is generally 

 employed to ascertain the presence or absence of brine, that when 

 this is present, the boring rods having arrived at a sufficient 

 depth, fall some distance without encountering any resist- 

 ing solid, and immediately the supply of brine springs up. The 

 boring being continued, indications of rock-salt are next found. 

 On the other hand where no fluid is met with, this non-resistance 

 of the boring rods does not take place, thus shewing that the ca- 

 vities where the brine springs occur are never in a dry state, and 

 no doubt are produced by solution of the mineral, occasioned 

 by its contact with water. At Droitwich the extent through 

 which the boring rods have been observed to fall, has been in- 

 creased, within the last twenty years, from about three feet to 

 nine feet and upwards; from which we may conclude that a 

 gradual wasting of the rock-salt continually takes place. 



