75 / 330
600
MTSCELLi\NEOUS
VALUABLE
RECEIPTS.
75
No.
137.
Another
cheap
Black
Ink.
Take
1
dracbm
prussiate
of
potash.
1
drachm
bichromate
of
potash.
1
ounce
extract
of
logwood.
1
gallon
water.
Mix
all
together
and
shake
it
well
;
when
dissolved,
it
is
fit
for
use.
No.
138.
How
to
make
Black
Printers'
Ink,
Printers'
ink
is
a
real
black
paint,
composed
of
lampblack
and
linseed-oil,
which
has
undergone
a
degree
of
heat
superior
to
that
of
common
drying
oils.
The
manner
of
preparing
it
is
extremely
sim-
ple.
Boil
linseed-oil
in
a
large
iron
pot
for
8
hours,
adding
to
it
bits
of
toasted
bread
for
the
purpose
of*
absorbing
the
w^ater
contained
in
the
oil
;
let
it
rest
till
the
following
morning,
and
then
expose
it
to
the
same
degree
of
heat
for
8
hours
more,
or
till
it
has
acquired
the
consistence
required
;
then
add
lamp-
black
worked
up
with
a
mixture
of
oil
of
turpentine
and
turpentine.
The
consistence
depends
on
the
degree
of
heat
given
to
the
oil,
and
the
quantity
of
lampblack
mixed
up
with
it;
and
this
consistence
is
regulated
by
the
strength
of
the
paper
for
which
the
ink
is
intended.
The
preparation
of
printers'
ink
should
take
place
in
the
open
air,
to
prevent
the
bad
effects
arising
from
the
vapour
of
the
burnt
oil,
and,
in
particular,
to
guard
against
accident
by
fire.