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THE
COMPLETE
PRACTICAI
DISTILLER.
however,
is
by
no
means
so
complete
as
of
the
sugar,
many
of
the
full-bodied
ales,
for
example,
retaining
much
of
their
clamminess
and
gelatinous
density,
even
after
having
undergone
a
very
perfect
fermentation.
Atmospheric
air,
it
seems,
has
a
no
less
share
whatever
in
vinous
fermentation
;
for
it
will
take
place
full
as
welj
in
closed
as
in
open
vessels,
provided
space
is
allowed
for
the
expansion
of
the
materials
and
the
copious
production
of
gas.
The
great
question
to
be
determined
is,
What
may
be
the
substance
or
circumstance
which
disposes
sugar
to
ferment
?
for
it
has
been
proved
that
sugar
will
not
of
itself
begin
this
spontaneous
change
into
carbonic
acid
and
alcohol,
though
when
once
begun
the
process
will
probably
go
on
without
further
assistance.
Some
of
the
most
common
fermenting
ingredients,
as
the
sweet
in-
fusion
of
malt,
technically
called
wort,
it
is
well
known,
will
slowly
enter
into
fermentation
without
the
addition
of
yeast;
hence
chemists
have
sought
in
this
substance
for
the
principle
which
gives
the
first
impulse
to
the
fer-
mentation
of
sugar.
Generally,
it
has
been
supposed
that
no
substance
en-
ters
into
the
vinous
fermentation
except
sugar,
or
from
which
sugar
may
be
extracted,
and
that
the
process of
malting
grain
was
necessary
to
develop
the
sugar
or
sac-
charine
matter,
to
render
it
susceptible
of
vinous
fermenta-
tion.
The
practice,
however,
of
grain
distillers
proves
this
to
be
a
mistake,
as
they
obtain
as
much
spirit
from
a
mix-
ture
of
malted
barley
with
unmalted
grain
as
if
the
whole
were
malted.
The
properties
of
the
fermented
liquor,
its
odour,
pungency,
and
intoxicating
quality,
are
owing
to
the
presence
of
a
substance
which
can
be
separated
horn