IN CERTAIN MINERAL WATERS OF SOUTH BRITAIN. 
231 
portion of earthy muriates is usually greater in them than in the brine-springs 
properly so called ; because the muriatic acid disengaged by the action of the 
sulphuric acid upon the common salt has dissolved a fresh quantity of lime or 
magnesia from the surrounding materials of the rock. 
If such be the origin of the sulphates of soda and magnesia which impart to 
these waters their aperient quality, it would be natural to expect that they 
should be found in greater abundance on the first discovery of the spring than 
after it has been long drawn upon ; and hence, perhaps, the remarkable dis- 
crepancy between the results of my examination of the Gloucester and some 
other waters, and those given on the authority of former chemists, may be 
explained, without impeaching the accuracy of either. 
It will be seen by reference to the Table, that I have represented the ingre- 
dients of the Leamington waters on the authority of Dr. Thomson, as stated 
by Dr. Loudon in his Practical Dissertation* on these springs ; and those of 
Cheltenham, with the exception of one lately discovered at Pittville, on that 
of Dr. Scudamore. The springs of Tewkesbury and Gloucester I have myself 
examined ; there being of the former no analysis at all, and of the latter only 
one by Mr. Accum, which I had reason to believe, what I in fact found, quite 
inapplicable to its present composition. The spring which goes by the name of 
the Chalybeate Saline is at present destitute of iron, which I am assured it 
formerly possessed, whilst the Sulphureous contains no trace of sulphuretted 
hydrogen. These two springs, which at present appear almost identical, are 
the ones most strongly impregnated with purgative salts, and therefore ap- 
proximate more nearly to the character of that analysed by Mr. Accum, 
according to his representation, than either of those termed “ the pure saline,” 
which he professed to have examined. Many of these springs it will be seen 
contain traces of bromine and iodine ; but they seem to be less common in the 
aperient waters which are occasionally met with in the chalk and tertiary dis- 
tricts of this country ; for I have examined three — those, namely, of Epsom, of 
Chad’s Well in Gray’s-Inn Lane, and of St. Leonard’s Hill near Windsor, 
without discovering traces of iodine in any one. In the Epsom water alone a 
slight trace of bromine was perceptible. 
With regard to the state of combination in which these principles occur, I 
* Leamington, 1828 . 
2 H 
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