Mr. A. B. Northcote on the Brine-springs of Worcestershire. 35 



this might appear most probable, when we remember that (taking 

 into consideration the difference in the level of the localities) the 

 same depth has to be reached before the brine can be obtained, 

 yet I cannot but think tbat one circumstance tends to show that 

 this view is not the correct one ; for if such were the case, the 

 brine should in each instance rise to the same level in the dif- 

 ferent shafts when left undisturbed by the action of the pumps. 

 Now under these conditions, the height to which it ascends at 

 Droitwich is about 166 feet ; whilst at Stoke, starting from very 

 nearly the same level, the column of water rises to a height of 

 483 feet ; this of itself is sufficient to show that no direct com- 

 munication can take place between these two springs without 

 supposing a violation of one of the first principles of hydrostatics. 

 It might then be thought that a reference to the analyses before 

 given might decide this question ; but on comparing the consti- 

 tuents of the two wMers, we can easily see that, taken alone, they 

 prove nothing, since the differences are such as might readily be 

 found in the same water when passing over slightly differing 

 deposits. If the stream ran from Stoke to Droitwich, we might 

 suppose that in its course it met with strata containing more 

 sulphate of lime than it had as yet encountered, and at the same 

 time was somewhat diluted with streams poorer in chloride of 

 sodium ; but I rather incline to think, that even from the com- 

 position of the brines, there is no reason to suppose that such a 

 direct communication exists; their great similarity may easily be 

 accounted for by supposing an equal similarity in the composition 

 of the entire strata of rock-salt from which they are derived. 

 Numerous freshwater streams occur in the higher parts of these 

 deposits ; in fact, no less than three are encountered, and have 

 to be guarded against in the Stoke shafts, and these doubtless 

 fed by rain-water permeate the strata in various directions, and 

 dissolve the rock-salt with which they come in contact. Mr. 

 Corbett informs me that the salt from which his brine is drawn 

 is perfectly transparent, which clearly accounts for the fact of 

 the Stoke brine containing less sulphate of lime, while the some- 

 what diminished strength of the Droitwich brine is probably due 

 to the less perfect exclusion of the freshwater springs of the 

 upper strata from the shaft which reaches the reservoir. Their 

 striking similarity in other respects, the identity of their tempe- 

 rature, and of the traces of substances which they contain, point 

 to an identity also in the composition of the deposit from which 

 they arc formed, of the solvent which renders them available, and 

 of the manner in which they are produced. 



I cannot conclude without expressing my thanks to Sir Charles 

 Hastings for the assistance which he has afforded me in obtaining 

 the Droitwich water, and also to Messrs. Clay and Corbett for 

 the valuable information which they have given me on the subject. 



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