MINERAL WATERS AND MEDICINAL SPRINGS OF ESSEX. 245
since Mr. Phillips analysed it. The two results are as
follows, if the dry residues left after evaporation, etc., are
compared :—
This, too, may be regarded as a genuine Mineral Water, and
it is of greater strength than any other Essex water we have
examined, though its constituents render it only slightly aperient.
The lime salts it contains have no medicinal value. It contains
a larger proportion of sodium chloride than any other Essex
water we have examined. Whence this is derived is difficult to
conjecture; but the sulphates of lime and magnesia come
undoubtedly from the London Clay, which, in many places, is
intersected in all directions with very thin laminae of crystals of
sulphate of calcium and sulphate of magnesium.
Mr. H. W. Bristow, F.G.S., late of the Geological Survey,
writing of the Hockley District, says144 : —
" Sulphate of magnesia is also present in other water from the London Clay of
this distinct. The farmer at Plumberrow Hall [in Hockley] told me that his
sheep, on being freshly brought to the farm from some other part of the county,
were violently affected (scoured) by the change of water, but that, after a while,
the unpleasant effects of the water wore off, and the sheep looked in better
condition than at first.
(24).—The Dovercourt Spa.—The very latest attempt to
establish a regular spa in Essex was made at Dovercourt rather
more than half-a-century ago. The attempt was more or less
successful, for the spa still exists to-day.
Silas Taylor, keeper of the King's Stores at Harwich, writing
about the year 1676, mentions145 a spring coming out of the cliffs
between Harwich and the Beacon Hill, which yields, he says,
"excellent clear and delightful water, well approved of by those
144 Geol. of London and Part of the Thames Valley, i., p. 261 (Geol. Survey Mem., 1889).
145 Dale, Hist. of Harwich and Dovercourt, p. 100 (1730).