Evening star., 1939-07-22
Story Of Pigments
Traced 10 1000 B. e.;
Chemistry Now Aids
In Fact, Modern Science
Hos Almost Entirely
Displaced Old Sources

It's not a modern invention to
paint houses regularly. Scientists
have discovered that the prehistoric
Indians were required to paint their
pueblos every four years in ac-
cordance with a religious ceremony.
The story of pigments. in fact, has
been traced back to 5000 BIC, when
Egyptian blue" the first paint
known to be compounded from Or
ganic substances, existed. Paint as a
protective covering for buildings was
known by the Egyptians, ancient
Chinese and Mayans.
Pigments. which supply color and
hiding power to paint, are manufac-
tured in powdered form. They are
then mixed with oil and other ingre-
dients that hasten drying, to a
smooth, flexible paste. Pigments are
classed-chemically-as either Or
ganic or inorganic. Formerly Or
ganic substances were formed by
living organisms, vegetable or ami
NAL; inorganic substances occur
naturally in minerals and other inert
materials. Chemists are now able,
however. to produce organic sub
stances in which the growth of Or
ganisms has played no part. Coal
tar dyes are typical Of these.
Up to century ago there was no
substitute for the vegetable dyes OBJ
tanned from plants Now they are
replaced by colors made through the
distillation of soft coal. Strangely
enough, coal tar dyes were dis
covered accidentally when an Eng
lish chemist broke his thermometer
in a chemical solution and indigo
blue resulted Before that. indigo
had been extracted from plant ma
tive to India.
Triumph of Chemistry.
From the time OF this discovery
on, all manner of coal tar dyes have
been developed exceeding in quality
and uniformity any vegetable dyes
known. Not only are they more
brilliant and permanent, but also
less expensive to produce
1t used to be that exquisite but
f1eeting shades of rose and red were
obtained from the madder plant of
Southern Europe. Now the best
pinks are made from chemical dyes:
Alizarine, eosine and lithol reds. The
bright. flaming reds used on fire
engines and gasoline pumps are the
toluldines, brilliant, expensive but
permanent. Next in rank are the
para reds of which more, perhaps,
are used in the paint industry than
all other dye pigments put together
These superseded the old, crudely
produced reds. In 1850 the Aztecs
learned to grind cochineal insects
for scarlet dye, though scarlet was
originally made from the kermes
insect found on Asian and European
oaks. This dye-the tola or tola-
schini mentioned in Hebrew scrip
lures and called coccus by the an
cient Romans and Greeks, is the
Oldest recorded dyestuff. Vermilion
was formerly made by burning mer-
curry with sulphur and, previous to
that, by grinding cinnaber. Both
Indian red and Venetian red are
mineral pigments with considerable
oxide iron content.
Brown and tan paints, too, are
largely colored with earth pigments.
Sienna, named for town near
Rome, is clay stained with iron
compounds. Sienna is also found
in Tuscany. the Hartz Mountains
and the United States. Burnt
sienna is made by roasting Sienna
earth.
Cuttlefish Provides Sepia.
From the Island of Cyprus comes
lumber earth, though England,
France and Wales as well as the
United States produce inferior prod
ucts. Germany knows it as Cologne
earth. Another brown tone is OBJ
tanned from asphalt-preferably the
genuine Syrian or Egyptian asphalt
tum secured from the Dead Sea.
From the dried inkbag of the cut
tlefsh-from which the fish elects
a dark liquid for defense purposes
-sepia is extracted, although a
manufactured product is more COM
monty used. Other browns as we'll
as some of the yellows and greens
also come from various earths. Ar
tiflcially produced ultramarine blues
are superior to that ground from ma
tive ores-lapis lazuli-originally
mined in Tibet, Persia, China, ST.
IBERIA and the Andes. The name
ultramarine means beyond the
seas"