Evening star., 1936-12-05

Chemist detectives, armed with some
OF the most precise instruments OF MOD
ern science, protect the stomachs OF the
American people.
DEVELOPMENT of methods by which un-
believably minute quantities of adulter-
ants and poisons can be determined has
inst been announced by the Food and
Drug Administration of the Department
of Agriculture The Spectromer, the
photo electric photometer and the elec-
tron counter-instruments used Dy
astronomers TO determine the constitu-
tion of distant stars-are being used TO
track down the food criminals.
A notable instance is reported by Direc-
tor w. G. Campbell Of the development
at the Massachusetts, Institute OF Tech
nology OF an instrument that will detect
as little as three -billionths of an ounce
of radium in a drug preparation In less
than five minutes. 1t counts the eiec-
irons resulting from the impact OF the
gamma rays OF the radium on the
molecules of the preparation and RECORDS
the counting rate on dial. Still another
method makes it possible to detect as
little as two-thousandth OF milllgram
of the poisonous element mercury In
foods.
Recent discovery that the element
selenium, closely related to sulphur and
which is absorbed from the soil by grow
ing plants, is extremely poisonous has
led to the development of chemical
methods by which the most minute
amounts can be detected. Another ele-
ment which sometimes is found in foods
and which is very poisonous in any con-
80 MI 10 Am
produces Spotting of the enamel Of the
teeth. 1t is now possible to make 100
per cent recovery of iuorine in . sample
of food.
OF wider application is q new method
perfected for determining very precisely
the lead content of q food sample BY
this method it is possible to estimate
one one-thouSandth of q milligram OF
lead with two per cent error. AS little
as one fve-thousandth of q milligram
may be detected. The method has been
used successfully in determining the lead
content of food colors and of single sticks
of chewing gum.
The presence of actually poisonous
elements in foods is seldom intentional
on the part Of the makers, Mr.. Campbell's
report points out. 1t is quite different
with cases of adulteration resulting in q
product which may not be harmful, per
sc. There has been an increase in such
cases-sO much so, ne believes, that the
bootleggers who acquired techniques of
adulterating liquor and who were thrown
out Of employment by the repeal Of pro-
hibition are applying their talents to the
food field. Sometimes their methods are
very 'difhcult to detect, even with the
precise scientific instruments available to
the Department OF Agriculture chemists.
A notable case cleared up during the
year was the tea-seed oil racket" This
oil Is obtained from the seed of plant
very similar 10 the beverage tea plant
and Is produced in large quantities IN
the Orient. There has been q limited
American market for it as an ingredient
Of paints and varnishes. For several
months earlier in the. year tea-seed oil
imports were increasing very rapidly, as
recorded by the customs service. They
were far greater than could possibly be
used by the paint industry, and this
naturally arodsed suspicion.
Now chemically tea-seed oil Il almost
indistinguishabl from olive oil used tn
cooking. The difference can be detected
only by very rigid testn The tea oil,
however, is very much {sHeaper and. 1t