The Saline County journal. [volume] (Salina, Kan.) 1871-1893, 1878-12-19

Under the name of sympathetic inks
are designated certain liquids which,
being used for writing, leave no visible
traces on the paper, but which, through
the sgeLcy Of heat, or BY the action Of
chemicals, arc made TO appesr in various
colors. The use Of such means for 90
cree correspondence 10 very ancient.
Ovid, Pliny, and other Roman writers
speak of m ink Of this kind, which,
however, Was nothing moro than fresh
milk. 1t merely suficed TO dust pow.
dsred charcoal over the surface Of the
paper upon which characters had been
trscsd with the oolorlsss fluid, whom tho
black powder adhered Only 70 those pla-
oes whore the fatty matter Of the milk
had spread. Such process, however,
WAS merely mechanical, and the results
very crude.
A great number OF sympathetic inks
may be obtained BY means Of reactions
known 70 chemistry. For instance,
write on paper with colorless solution
Of sugar Of lead ii tho water that is used
for tho solution be pure, no trace Of the
writing will remain when it becomes
dry. Now hold the paper over . jet of
sulphursted hydrogen, and the chsrac.
ters will Immediately appear on tho pa.
per, OF an intense black color. The fol.
lowing recipes for inks of this kind are
more simple: II writing be executed
with 0 dilute solution OF sulphate of
iron, tho invisible characters will
sppear of . beautiful blac, if the
dry paper DO brushed over With . pen.
oil full Of . solution Of yellow prussiate
Of potash ; or they will be black, if So
luton of tanuin b substituted tor the
prusslate. II the characters b written
With solution Of sulphats of copper,
they will at once turn blue on exposing
TO the vapors of ammonia. Another
sympathetic ink 10 Afforded by chloride
Of gold, which becomes Of . reddish pur.
pie whom acted upon by salt Of tin. A
red sympathetic ink may b made in the
following manner: Write with very
dilute solution of psrchlorids of iron-
90 dilute, indeed, that the writing will
DO Invisible when dry. BY holding the
paper in the vapor arising from . long.
necked glass flask containing sulphuric
acid aud . few drops Of . solution OF
sulpho-cyaoids Of potassium, the charac-
tors will appear Of . blood.rod color,
which wall again disappear on submit.
ting them to the vspors Of caustic am.
monia. This experiment can be repeat
cd ad infaitxm.
During the war in India, some years
ago, important correspondence was car
RED on by means Of the use OF rice wa
tor - Q writing fluid. On the applica-
ton Of iodine the dispatches immediate
~ appeared 10 blue characters.
Sympathetic inks which are developed
under the influence Of heat only are
much easier TO use than tho foregoing.
The liquids which possess such q prop.
erty are very numerous. Almost every
ono perhaps knows that il writing be
executed on paper with clean quill pen
dipped in onion or turoip juice, it be-
comes absolutely invisible when dry
and that when the paper 10 heated the
writing ct once makes it, appearance in
characters Of . brown color. All album
mold, mucilaginous, end sacchariae veg
etable juices make excellent o. mpathetic
inks; We may cite, - among the best,
the juices of lemon, orange, apple and
pear. A dilute solution Of chloride Of
copper used for writing 10 invisible until
the color 10 heated, when the letters
are seen of beautiful yellow, dis
appearing again whom the heat that
developed them is removed. The
salts Of cobalt, - the acetate, nitrate, sui.
phate, and chloride, possss . like prop
erty. When dilute solution Of these
salts 10 used - sn INK, the writing, al.
though invisible whom dry, becomes
blue when exposed to heat. The adj.
ton OF chloride Of iron, or Of . salt
of nickel, renders them green,
and this opens the way for . very pretty
II . winter Landscape DO
drawn 10 India ink, and the sky be
painted with wash Of cobalt alone, and
the branches Of the trees b clothed With
leaves executed With . mixture Of cobalt
and nickel. and TIE snov-clsd earth Do
washed over With the same mixture,
magic transformation - once takes place
on the application Of heat, the winter
Landscape changing 10 . summer scene.
-Scientific Am1sican.
rsise1 y lseRs. =,
We are panied % learn that Miss Cary
he's bssa guilty Of The absurdity ofwear.
isR dia0ood brooch in "xastha," and
that Mics Litta Wors dismood sar-siags
. a a