70 APPENDIX.
had died through drinking too much of its water, it was stated by
Dr. J. M. Ryan, of Colchester (see report in Essex County
Chronicle, 10th June 1910) that "a lot of people bathed their eyes
with the water from this spring and he thought that, in mild cases,
it was useful."
The Woodford Wells (p. 31).—These were referred to, but not
described, in 1833, by Prof. A. Booth (Mirror, xxi, p. 229).
The Chigwell Row Spring (p. 43).—Prof. A. Booth, writing in
1833 (Mirror, xxi, p. 228), says :—" It is now quite neglected.'
APPENDIX.
Critical Note by Mr. W. H. Dalton, F.G.S.
I have but little more to say on this very interesting topic, as
the authors have already embodied in their account all the deter-
minations or surmises I have been able to offer as to the geological
conditions of the several mineral springs, where their positions are
sufficiently ascertained.
It will be seen that, with the exception of Tilbury, all the
springs noticed are within the area of the London Clay, and their
waters are derived either from sandy seams in that deposit or from
its contact with superficial gravels over it, the gravels in the latter
case furnishing merely the water, and the mineral ingredients being
derived from the clay. In no case does the Boulder-clay take any part,
so that the calcareous and ferruginous elements are always of local
origin : at least, having been in the country from Eocene times, they
cannot be regarded as of modern importation.
At Tilbury, where the source is in the Thanet Sand, the alkaline
elements are probably also native, but here there may be some
lateral admixture of marine salts from the adjacent estuary, besides
those of organic contamination.
For the alleged beneficial action, I incline, with the authors, to
assign the major part to the element of faith, but the mild action of
the magnesian and ferric salts, concurrent with duly-ordered life,
doubtless had its advantageous effect, similarly to that of the
substitutes of modern fashion.
We now prefer our health "made in Germany" or thereabouts.