53 / 308
WATER.
53
These
ingredients
are
partly
disposed
of
again
by
fil-
tering
through
rocks
and
gravelly
soil.
Spring-water
contains
substances
of
the
soil;
these,
varying
accord-
ing
to
the
soil's
composition,
are
useful,
and
in
many
cases
indispensable
for
the
organisms.
The
sparkling
of
the
water
indicates
the
presence
of
gases,
without
which
it
is
never
refreshing.
Boiling
will
drive
out
all
gases,
precipitate
the
bicarbonate
of
lime
and
some
of
the
coagulable
matters,
and
destroy
some
of
the
germs
of
disease.
Solids
fixa
as
we
find
in
water,
are
chiefly
combinations
of
calcium,
magne-
sium,
alkali
metals,
aluminium,
iron,
manganese
in
form
of
carbonates,
chlorides,
sulphates,
silicates,
etc.,
and
organic
particles.
Good
and
palatable
drinking
water
should
contain
less
than
yrnnj-
of
these
fixa;
some
of
them
are
better
not
found
at
all,
and
if
they
are,
they
should
be
in
the
smallest
possible
proportions.
The
limit
of
lime
is
-g-oVcj;
to
great
a
percentage
of
magnesia
is
harmful.
Organic
particles
should
be
not
more
than
to
require
fa
to
-fa
%
of
oxygen
for
their
oxidation,
i.
e.,
as
a
maxi-
mum
T-J&TT
%-
The
reasons
why
waters not
answering
these
require-
ments
are
doomed,
are:
Firstly,
it
is
proven
beyond
any
doubt
that
the
spreading
of
epidemics
is
in
the
closest
connection
with
the
composition
of water,
which,
having
absorbed
germs
of
disease
on one
place,
deposited
them
on
another;
secondly,
the
presence
of
too
great
quantities
of
organic
matter,
as
also
of
am-