OLIVEE: MINEEAL SPEINGS OF THE WEST EIDING. 339 
spring from deeper sources than the iron. 
All about the Alum well, near the centre of this group of waters 
vegetation is very scanty ; and the barren ground when moist, as 
after rain, affords an acid reaction to litmus paper. This fact is 
connected with the formation of Persulphate of Iron and Alum which 
drain into a shallow well, and which — like the production of alum 
from the oxidation of iron-pyrites — is derived from the action of the 
oxygen-laden rain reaching through the porous soil, superficial 
deposits of Sulphide or Iron (the black precipitate resulting from 
the mixing of the sulphur and iron waters). In the excavations 
lately made about the Alum Well, I noticed an abundance of this 
inky looking product in the sludge and shales ; and the alum water 
ceased to collect below a certain level. During the past 150 years, 
at least, this water has been repeatedly discovered and lost : a fact 
which is doubtless to be explained by the superficial origin of the 
water, and by attempts to improve the yield of it by deepening the 
well. 
If a line be drawn from the north side of Harlow Hill, in a 
north-easterly direction to the Old Sulphur Well in Low Harrogate, 
it will intersect this group of sulphur waters, and indicate the 
track of an anticlinal axis, of which we have direct evidence in 
the opposing dips of the Yoredale Limestone well exposed in the 
quarries on either side of the Bogs-Field, and it is believed that the 
waters rise through the shales which underlie this bed of Limestone. 
(h ) Low Harrogate Waters. — About forty wells of sulphur and 
iron waters are scattered over Low Harrogate. Here again it is 
easy to define in a general way the area of strong sulphur issues, 
and that of the iron saline waters :^ the former coinciding with the 
vicinities of the Royal Pump Room, and of the western side of the 
Montpellier Gardens ; and the latter being found on the northern 
side of these gardens, and in front of the Spa Concert Rooms. An 
outlying group of weak sulphur waters are found near the Victoria 
Baths. 
The most important issues in this area are the Old Sulphur 
Well, the MontpelUer Wells, and the Chloride of Iron Water. 
The Old Sulphur Spring. — On approaching the Royal Pump 
