VOL. XVII. (3) APPENDIX— WATERS OF CHELTENHAM 313 



domestic purposes including fitness to drink. Supplies of fresh 

 water of mediocre quality have thus been obtained from 

 shallow wells in the clay, but very often the water struck has 

 been too highly mineralised for ordinary drinking purposes, 

 having more or less the character of those medicinal springs 

 with which the name of Cheltenham is associated. The clay 

 in this locahty is generously productive of mineral waters. 

 It is sometimes capable of yielding a small quantity of ordinary 

 water to a shallow well sunk into its surface, but it is always 

 a dangerous expedient to deepen the well with the view of in- 

 creasing the quantity, as any further supply obtained by blast- 

 ing through a layer of hard rock, or otherwise deepening the 

 well is extremely hkely to be too highly mineralised for domestic 

 use, and it is probably true to say that any deep well sunk into 

 the clay in this immediate locaUty, if it yield any considerable 

 quantity of water at all, will supply a water more or less of the 

 quality of a mineral water. 



The mineralisation varies considerably both in quahty and 

 strength, sometimes the sulphates predominating, sometimes 

 the chlorides, the quahty of the yield of no two wells being alike 

 but often quite distinct and different, though the wells be only 

 a short distance apart. Sometimes the water has an odour of 

 sulphuretted hydrogen, though this is not very permanent, and 

 not to be compared with the malodorous water of Harrogate 

 and other spas. The same well will yield the same kind of 

 mineral water in approximately the same strength and rela- 

 tive proportion of dissolved salts for long periods of years, when 

 considerable quantities of water are being drawn from it, though 

 it cannot be mixed with a water yielded by another well a hun- 

 dred yards away, owing to differences in quality, properties and 

 flavour. Sometimes it is Sulphate of Soda with Sulphate of 

 Magnesia which is responsible for the mineral quality. Some- 

 times Chloride of Magnesia takes the place of the Sulphate, and 

 sometimes the Magnesia is in negligible quantity, sodium 

 chloride combined with more or less sodium sulphate making 

 up the chief constituents. One class of water is also rendered 

 distinctly alkaline by the presence of bicarbonate of sodium. 

 The amount of chloride of sodium varies very much : from a 

 few grains per gallon up to 400 grains or more, such a quantity 



