250 MINERAL WATERS AND MEDICINAL SPRINGS OF ESSEX.
V.—GENERAL REMARKS ON THE MINERAL
SPRINGS OF ESSEX FROM THE CHEMICAL POINT
OF VIEW.—All the earlier writers who treated of the Mineral
Waters of the County discussed very fully the chemical nature
of those waters. Each propounded, with much solemnity and
an air of profound wisdom, a great deal of absurd nonsense,
which elucidated nothing. Such vague and pointless observa-
tions were usual in scientific works of the period—indeed,
nothing of greater value could be expected in days when even
the existence of the element oxygen was unknown. The
remarks of these writers have, therefore, practically no value for
us now.
Two of the later writers on the subject (namely, Phillips and
Granville) record, however, investigations which still have
scientific value, and of these we have availed ourselves.
In nearly every case, therefore, we have found it necessary
to make our own investigations into the chemical composition of
the waters of our Essex mineral springs, or such of them as can
now be identified, and the result of each analysis has been given
in its proper place above.
The methods of analysis followed cannot be described here,
but they were identical with those given in detail in Dr.
Thresh's book on The Examination of Water and Water Supplies,
pp. 233-260 (1904). Such detailed analyses as those referred to
in Chapter xiv. of the above work require weeks to complete ;
hence our attention was directed to the chief constituents and the
estimation of all such as occurred in appreciable quantities.
Very many waters of a similar character to those analysed
have been examined in Dr. Thresh's laboratory in recent years,
and Dr. Thresh informs us that he has never detected any of the
rarer elements, nor even traces of iodides, bromides, or fluorides,
nor of salts of lithium, barium, rubidium, arsenic, etc., and that,
except in polluted waters, potassium salts are only present in
traces. We did not make, therefore, any special search for any
of the above ; but, had any been present in appreciable quantity,
our results would have given some indication thereof and further
tests would have been made. The absence of these constituents
is only what might be expected from our knowledge of the
natures of the waters and of the geological formations from
which they are derived.