OLIVEE: MINERAL SPRINGS OF THE WEST RIDING. 347 
of marine forms of life, but such as possibly afforded at times oppor- 
tunities for saliferous precipitation. The presence of iodine and 
bromine (as, for example, the definite quantities recorded by Professor 
Thorpe in his analyses of the Old Sulphur Spring- and the Montpellier 
Strong- Sulphur) in these waters favours the marine origin of their 
salines : and furthermore the detection of manganese in the Chloride 
of Iron water, in quantity sufficient to be determined by Mr. Botham- 
ley, suggests the same conclusion, for Dieulafait has shown that 
manganese bicarbonate exists in the waters of all seas and oceans, 
and Berthelot has pointed out that in contact with oxygen it becomes 
binoxide, which sinks and accumulates on the ocean bed, where a 
large quantity of manganiferous mud is found. 
(3) Volcanic Salt. — Sir Charles Lyell was favourable to the 
volcanic origin of the saline impregnation of many mineral springs. 
He says, " as muriate of soda is one of the products of volcanic 
emenations, and of springs in volcanic regions, the original source of 
the salt may be as deep-seated as that of lava." {Principles of 
Geology, 10th Ed. vol. T., p. 411.) 
There is, however, no evidence whatever to show that an active 
volcano ever existed here : and though we may speculate as to the 
share which volcanic agency may have taken in displacing the 
water-born strata, there are no facts to warrant a belief in this mode 
of origin of the salt. Besides, there is the undoubted fact that of 
all the mineral waters distinctly referrible to vulcaninity — such as 
those of the Pyrenees, of the Auvergne, and of active volcanic 
areas — there is not one that can in any degree approach the large 
proportion of salt present in the brine issues of Harrogate. 
2. The Sulphide. 
Various theories have been advocated from time to time in order 
to explain the presence of sulphide in the Harrogate and other 
sulphur waters. I will pass some of them briefly in review. 
(1) The reduction of Sulphates into Sulphides or Sulph-hydrates 
by means of living organisms (confervae)*, or by organic matter — 
* M. Blanchard's experiments with confervae taken from a sulphuretted 
mineral spring conclusively show that these organisms, when a soluble sulphate 
is present, live at the expense of the combined oxygen, and in this way sulphiir- 
ate the water. See Gompt. Rend., vol. 89. 
