ORIGIN OF MINERAL WATERS EXPLAINED. 



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accumulation of the mineral in these particular points is due to the same agency by 

 which the strata were dislocated and altered. Sulphuret of iron is, doubtless, generally 

 diffused through almost every formation ; but in this region I never observed it in cry- 

 stalline bunches, except at the junction of the trap with the altered rocks. 



If, therefore, it has been inferred that the mineral veins of the district of Shelve in 

 Shropshire resulted from volcanic action, so is it inferred that the numerous mineral 

 sources which issue from the flanks and extremities of this disturbed tract, at Llan- 

 degley, Blaen Eddw, Llandrindod and Builth, are due to a similar cause. 



The great diversity of composition of the waters which issue from contiguous springs 

 at Llandrindod, is to be accounted for in the same way as at the Park Wells near 

 Builth. These shades of difference, however unimportant to the geologist, who simply 

 endeavours to expound the mode of action by which they have been evolved, are points 

 of high interest to the chemist and of great value to mankind, some of the least per- 

 ceptible of these ingredients being of great importance in their effects upon the human 

 body. With the permission of my friend Dr. Daubeny, I therefore annex in the Ap- 

 pendix his able analyses of the waters of Llandrindod, Builth, and Llandegley 1 . 



1 Dr. Daubeny recently undertook this examination with the view of ascertaining whether all these mineral 

 sources which issue from strata known to have formed beneath the sea did not contain iodine and bromine, 

 which modern French chemistry has shown to be of marine origin. These labours have confirmed expectations 

 founded upon just philosophical principles, and have by mineral tests completed to a great extent, the proofs of 

 the submarine formation of those strata in which the research of geologists has pointed out the remains of so 

 many marine animals. To render, however, this argument quite valid, all strata inclosing marine shells ought 

 to contain iodine, bromine, and muriate of soda. 



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