MINERAL WATERS AND MEDICINAL SPRINGS OF ESSEX. 235
Chelmer are underlaid, at or near that level, by the London
Clay. On the Baddow side, some Lower Glacial Boulder-clay
intervenes, not separately mapped, but noted as brickearth on
the Survey map ; and I suspect the same on the northern bank,
more or less draped by the washing down of the gravel. This,
by furnishing lime to the sulphuric acid of the London Clay,
would yield a slightly selenitic water."
(19).—The Twinstead Spring.—In the year 1791, a mineral
spring was discovered in the parsonage glebe at this place. Sir
James Marriott, Knight,128 who then owned Twinstead Hall,
writing from Snaresbrook on 19 July 1791, tells of the number of
visitors attracted to the village to see the church, which he had
recently rebuilt, and adds129 :—
" A medical man has discovered a very light mineral and sulphureous spring in
the glebe of the parsonage, and so he, with his brethren, will have an interest in
puffing [the place]."
Mr. Dalton surmises that the well in question was probably
at the junction of the Glacial-gravels with the lower part of the
London Clay. He adds that the Reading Beds outcrop within
a mile eastward from the church, in the floor of the side-valley
between Twinstead and Great Henny.
(20).—St. Chad's Well at Ilford.—A well to which curative
properties have been ascribed exists near Little Heath, in Great
Ilford. Mr. G. E. Tasker speaks 130 of it as
" a reputed medicinal well in Billett Lane, near Little Heath, which was at one
time much resorted to by persons with weak eyesight, for the special properties
of the water were supposed to be beneficial to the eyes. It is possible that the
well may have existed at the time of the brother bishops, for it was often the
custom among missionaries in those far-off days to baptise their converts at some
well or spring which happened to be handy. These wells frequently took the
name of the holy man, and it is said that Cedd held a baptism at this spot, and
because of the healing qualities of the water, and in memory of his brother Chad,
whose fame had spread all over the country, it became known to future genera-
tions at St. Chad's Well.
" Be that as it may, the well in Billett Lane has existed a long time, and
there is very little doubt that it gave its name to the two hamlets of Chadwell
Street and Chadwell Heath. It lies quite solitary on the roadside, and is partly
protected by an alcove of brickwork. Its appearance is so strange at dusk that
horses unused to the road often 'shy' at it. The water is of excellent quality ;
128 Sir James Marriott (1730-1803) was a judge, an M.P., and a vice-chancellor of
the University of Cambridge. He died at Twinstead Hall, aged 73.
129 See Essex Review, xv., p. 198 (1906). The original letter is in the Bodleian Library
130 Ilford, Past and Present, pp. 108-109 (1904).