222
THE ESSEX NATURALIST.
with two other small patches near by, on the north and south.
All these are duly noticed in the Geological Survey Memoir, "The
Geology of London." etc., vol. i., p. 279 (1889).
It is clear, therefore, that on the higher parts of these hills
we must have the uppermost and usually more sandy part of
the London Clay, which of late years has been separated by
geologists under the name of Claygate Beds, from a village in
Surrey where they are well developed. It may seem strange
to take a name compounded of clay for a set of beds divided
from a great clay-formation on account of their more sandy charac-
ter, but I fear that geologists have never been noted for their
adherence to truth in matters of nomenclature.
It seems likely, then, that it may be owing to the presence of
the somewhat sandy Claygate Beds that water has found its way
downward from the surface, through the top part of the hill-
range, until it has reached the more clayey beds beneath. When
the Geological Survey extends its new work into S.E. Essex we
shall have direct evidence on this question ; meanwhile we may
have to be content with surmise.
By one of those curious coincidences which happen pretty
often, whilst the Essex Field Club was examining water that
may originate in the Claygate Beds (on May 12, 1923) the
Geologists' Association was disporting itself at Claygate.
Where the great quantity of the various salts in the water
come from, or how they may have been evolved in these beds,
is a question difficult to answer, and I leave it alone. Sulphate
of lime, of course, occurs in all clays.
It is notable that the fields around the wells are of small
agricultural value ; they are now in pasture, with a good deal
of scrub in the form of briar-bushes ; perhaps, therefore, roses
might be grown here. Can it be that the alkaline contents of
the loam and sandy clay are antagonistic to vegetation ?
There are other mineral waters in the neighbourhood, and
we may note one over two miles to the north-east, of the water
of which we have an analysis. This is at Luncies, in the parish
of Vange, about 3/4 of a mile north-westward of Pitsea Church.
I went there with Dr. Bullough, who kindly got for me the
analysis of the water, and we saw two wells, said to be about 20
and about 80 feet deep, the latter in the yard just west of the
house, from which the sample analysed was taken.