252 MINERAL WATERS AND MEDICINAL SPRINGS OF ESSEX.
wells, or some of them, really did possess, at one time, the
properties with which they were credited, and that those
properties have become, in some way, lost or exhausted. Possibly,
the water of medicinal value entered them originally at the
bottom, but in time became excluded somehow, either through
an accumulation of sediment or otherwise ; in which case,
pumping the well dry and cleaning it out might restore to it any
mineral properties it ever possessed. Possibly, again, such
mineral salts as existed originally in the strata immediately
adjacent to the well and gave character to its water have become,
in the course of time, dissolved out and exhausted, either wholly
or partly ; in which case, it would be difficult to restore to
the well its lost mineral properties. Moreover, it is possible
(as Mr. Dalton has suggested to us) that the nature of the
waters in some of our wells may have been changed greatly by
the accession of organic impurities, which have a considerable
chemical effect on some of the mineral salts, especially those of
iron and sulphuric acid. In this respect, disuse and deterioration
of our wells may, by mutual reaction, have greatly changed the
mineral constituents of their waters from those which obtained
originally.
We think it more probable, however (and in this we are
supported by the opinion of Dr. Thresh), that the waters of
our Essex wells never possessed, in fact, any real medicinal
value, and that "faith" was an important, if not the chief,
element in the "cures" they are credited with. Probably this
was the case even with our once-celebrated wells at West
Tilbury. It must be remembered that many wells and springs,
both in England and abroad, enjoy a high reputation for their
curative properties, although their waters, when analysed with
the utmost care, give no indication that they contain any sub-
stance of medicinal value.
We are bound, therefore, to conclude (at all events until
further evidence comes to hand) that the cures reported to
have been effected by the waters of some of our Essex springs
resulted, probably, in the main, from the drinkers' own belief in
the efficacy of the waters in question, though a period of quiet,
simple, orderly living on the part of the patient was, no doubt, a
necessary accompaniment of that belief.
At the same time, others of our Essex waters certainly