ON THE SALINE WATERS OF CHELTENHAM. 
147' 
verting to the probable geologic derivation of the waters, or at 
least of their chemical principles. 
Mr. Murchison in his Silurian System and also in a little 
work on the Geology of Cheltenham, has come to the conclusion 
that the salt springs, that is, the springs of chloride of sodium 
and water, are derived from the New Red Sandstone formation, 
and that they flow from this formation under the lias, and, from 
the greater elevations of most of the red-sand above the Lias on 
account of the dip of these beds, it finds its level by rising through 
the lias in any fissures or natural openings that may present 
themselves. This will be better understood by a reference to 
PI. IV. 
This salt water then, as derived from the saliferous deposit 
consisting of a solution of chloride of sodium, with a little 
chloride of magnesia in water, in its contact with the Lias 
becomes impregnated with the sulphates of soda and mag- 
nesia, and the carbonates of soda, lime, &c. and in proof of this 
position it will be sufficient to state that the deeper the lias beds 
which have to be pierced through in order to arrive at the saline, 
the greater will be the quantity of proximate principles, inde- 
pendent of the common salt, and the nearer the saline water is 
found on the borders of the New Red Sandstone formation^ the 
greater the quantity of common salt and the smaller the proportions 
of other ingredients. The foregoing opinion too, as to the origin 
and proportion of our medicated waters is further strengthened 
from chemical experiments which developed the presence of the 
materials before mentioned in the lias beds, although common 
salt bears an inappreciable quantity compared with that which 
is in the water, but the muriates, carbonates, and sulphates with 
iron, bromine, iodine &c, may all be detected in the lias clays, 
and it is a fact which my own experiments have verified that 
these layers of shale which present us with remains of marine 
plants yield, on analysis, soda, together with small quantities of 
iodine ; these facts then it is presumed will suffice to show that 
