Perth Amboy evening news., 1923-09-08

WASHINGTON, Sept. S:-A small
but important branch of the dye
industry, one which gets very little
space in the public prints, is the
manufacture of biological stains.
The Bureau of Chemistry is work.
ing on the Standardization of these
stains in cooperation with the Com
mission of Standardization of Bio
logical Stains and while the subject
is of greatest interest to science, it
has features which may interest the
general public as we'll.
Since bacteria which cause disease
were first identified, scientists have
studied them under the microscope.
In their natural state the tiny or
ganisms in a culture or drop of
blood may not make a distinct pic
ure even when magnifed. So the
bacteria are colored with weak solu-
lions of dyes.
Just as wool will take one kind
of dye and cotton will not, so GER
tain bacteria will take up a given
kind of dye while other bacteria in
the same culture remain unaffected.
If a culture OF a person with sore
throat is placed on a slide and stain
ed with the proper blue dye the
~diphtheria germs turn blue If n
are there. In the same way stains
of various colors are used by ply
sicians to show up tubercle bacilli,
pneumonia bacteria and yellow fever
parasites. With certain organisms
in colorful relief the bacteriologist
can study his bit of material and
watch for fermentation or other
chemical changes which would fur
Their prove the existence or potency
of the disease germs.
In diagnosing most contagious
diseases of which the bacteria are
known, stains play an important
part. Botanists use the biological
stains too, for plant study. Tissues
of a plant are brought into vivid
relief by the dyes, the result being
somewhat reminiscent of the green
yeinings in carnations which are
produced by putting the stems into
green ink. biologists, Psychologists,
in fact almost all "ologists" in
science, use stains. The amount
needed for an exhibit on a glass
slide to go under a microscope is in
flnitesimal. Even the noun of dye
consumed by the entire country for
biological stains is not great. But
when the German supply was cut
off by the war, a dye problem which
is still in existence was presented
to the United States.
Germany Had Monopoly
How Germany had built up a dye
industry of world Importance by 40
years of work on secret processes,
and how American dye makers had
to meet the war emergency with
only their knowledge Of the simpler
Idyes to help them is we'll known.
The story of the scientific stains
has been less often repeated. There
was on e German manufacture
who sold these stains, and his
method, of course, was not published.
The dyes had the names of textile
dyes, and when imports were cut
off manufacturers in this country
began at once to sell the textile
dyes they were making to doctors
and scientists.
But oftener than not the Ameri-
can colors had no effect on the bac-
eria. Doctors could only buy samp-
es here and there and try them all
until something satisfactory was
found This trial and error meant
waste and delay in important work
Often only a tiny sample Of bacteria
aden tissue would be available, and
he scientists found 1t extremely in
convenient to have to experiment
with dyes on such valuable material
After the war, the National Re-
search Council asked the Govern
nent to analyze samples of the pre-
war dyes, so that the formulas could
be accurately reproduced in this
ountry. The Bureau of Chemistry
in the Department Of Agriculture
has a color laboratory where samp-
es of food dyes are regularly in
pected before certiication. This
laboratory had the equipment and
the color experts, but tho simple
request for dye analysis was about
ike the Herculean tasks which were
set the prince n the old fairy stor-
les.
DR.. ]. A. Amber of the color
laboratory says that very little car
be learned by looking at the dyes
Two samples that apparently have
the same color elements may be
made differently. A school child
knows that brown may be produced
in water colors by yellow. red and
blue, or by purple and yellow, OF
BY ~Eed-orauge and blush green, o.
Z