Savannah courier. (Savannah, Tenn.) 1885-1979, 1892-06-16
INVISIBLE INK.
How the Kinds Used in sec,o, ,v.,n., :
Are Made

-
How the Kinds Used IN s.e,o, ,v.,n..
Are Made.
ut is very easy TO make an inv,sih,o
INK IL you wish to insure special secrecy
ior your correspondence" said n chem
ISL 10 writer for the Star "you have
only 70 do your writing with n solution
oi sugar OF lead in pure water, adding
10 the mixture ANAL amount of gum
arabic, so that II may flow we'll from
the pen. The letters traced with this
preparation are not visible when Il has
become dry, but when the manuscript
Is held over jet of sulphureted hydro
gen gas they come out intensely black
ms gas is the same as that generated
IN pad eggs, so that one or two of those
ihiRhs serve to do the reading by. How
ever one may avoid the necessity OF
peing tortured with unpleasant odors
oy selecting some other chemical for an
ink.
There Is nothing better for the pur>
pose than bromide of copper, which YOU
can prepare for yourself by mixing one
part OF bromide of potash, one part of
oiue vitriol and eight parts water, add
ing little alcohol and gum arabic.
writing done in this solution is abso-
iutely invisible until exposed to heat,
when 1T immediately becomes legible.
any dealer in chemical supplies will
sell you chloride of cobalt, TO which
you can add gum arabic 1t makes n
PINK script, which disappears when
ury' becomes green when heated. dis
appears when cold and is pink again
when damp. Writing done in rice wa
ter can not be seen when it is dry, but
turns blue when iodine is applied to it.
~ was much employed during the great
mutiny In India. Invisible inks have
been suggested for postal cards.
"Colored inks are made in all sorts OF
ways, out of anilinc dyes, dye-woods
and chemicals of various kinds Ground
Brazil wood is used for red ink, cam
peachy wood for purple, logwood for
violet, sulphate of indigo for blue, and
veroigris and cream of tartar for green.
Voal-tar colors may be employed in
place of these. You can manufacture
for yourself an excellent black writing
Ink by soaking a pound of bruised gals
for twenty-four hours in boiling wa.
ter, straining the liquid and adding
hive ounces of sulphate of iron, three
ounces of gum arabic and few drops
OF carbolic acid. The gall fluid acts
upon the sulphate of iron, making an
Intense black, and the carbolic acid il
intended to keep the ink from becoming
moldy. To make copying ink you have
only to mix three pints of the black inl
with one pint Of glycerine.
1.-THE basis of India ink is lamp
black, which is made in furnac,
specially constructed for the purpose
Various kinds of oils and grease ar,
burned to produce the lampblack, bu
the finest quality is obtained from porl
fat. The lampblack is subjected to
sitting process through silk bags in or
der that it shall be rendered as fine a.
possible. In the manufacture of tn,
ink the first step is to melt in pot
quantity of particularly excellen
glue from buffalo hides. To this a
much lampblack is added as will com
pose a soft paste, which is kneaded will
the hand, small quantity of pea oil be
ing put in also. The mixture is mad
into fiat cakes and left to 'ripen' TO
awhile, after which it is compressed il
cylindrical molds. The cylinders il
which shape The proaac. Is sent to maj
ket, are dried and given final polls
on the outside by brushing them wit
hard brush impregnated with the kin
of white wax which is deposited O.
trees in China by insects. A little mus
or Borneo camphor added to the past
while it is hot gives it's peculiar odor t
the best kind of India ink. Washing
ton Star.