Evening star., 1954-05-21
New Method Develops
Yedrs-OId Fineerprints
Moy Revolutionize Art
Of Criminal Investigation
By Thomas R. Henry

~ tHSthoS Ne
A chemical method of developing
flngerprints as long as IL years after
they are made-and probably indefi-
nitely-has just been reported by two
Swedish chemists.
It makes no difference how faint the
prints may have been in the first place.
The discovery came, report Drs.
Svante Oden and Bengt Won Hofsten
Of the Swedish University of Upsala.
as the result of q nuisance" which
turned UP in efforts to analyze' paper
by the relatively new chemical proce-
dure Of chromatography Fingerprints
Of everybody who had handled the
sample kept appearing and spelling
their results.
The system consists merely In spray
ing the surface of the object on which
the prints presumably were made with
a chemical known as ninhydrin. This
has strong reaction with the amino
acids, the misrepresentation basic
building blocks of the body AS many
as 10 Of these acids have been found
in human fingerprints.
When these combine with ninhydrin,
pinkish whorls appear few minutes
after the object has been placed in an
oven at temperature of about 80 de-
grees centigrade. The strongest marks
appear first, other lines continue to
appear for two or three days, until the
complete fingerprint is developed.
Print Is Mostly Water.
A fingerprint. the two chemists point
out, is composed of from IS to 95 per
cent water. The rest consists of fats,
salts and amino acid, all in such minute
quantities that they can be detected
only by delicate chemical procedures.
Evidently, however, all are equally dis
tributed over the print.
The water soon evaporates. Then in
most cases the print can no longer be
recovered by any of the conventional
methods. With the ninhydrin method.
however. prints not only are restored
but become more intensely pink with
time.
One of the Swedish chemists obtained
his own prints from a French gram
mar which he had used only as q school,
boy and which he was certain neither
he nor anybody else had touched for
IL years. The prints obtained were
absolutely identical with some OBJ
tanned the same day in the laboratory.
The finding has just been reported
through Nature, the official organ Of
the British Association for the Ad-
vancement of Science. It is predicted
that it may have far-reaching effects
on criminal Investigations and may
permit reopening of cases long since
closed.
The natural "gyroscope" Of flies and
mosquitoes, designed to keep them in
straight, level flight, now has been
copied by man to produce the most
delicately responsive instrument of this
type yet devised.
This is the gyrotron Of the Sperry
GyroScope Co., development of which
has just been announced in Nature. The
engineers have improved over the in
sects to the point where the instrument
will measure the rotation Of the earth
and the deviation from straight line
through space which 1t causes. Flies
don't need quite so accurate an instru-
ment. ar +.
..s Stabilizing Organ.
Just behind the wings Of all the
SO"CAlleQ OlpGcKhs Lklc CldSS W WILMA
flies and gnats belong, there is pair
Of club-shaped projections which pre-
sumably represent second pair Of
wings, long since discarded. When the
insect is in fight these 'halteres' are
in very rapid vibration. Recent studies
by the British biologist,Dr. j. w. S.
Pringle, demonstrated for the first time
the real purpose Of these projections.
At the base of each Is an extremely
sensitive sensory organ which detects
the slightest rotation, either vertically
or horizontally, and warns the insect
of any unintentional deviation from its
course. These organs apparently are
exclusive to the diptera and represent
q sixth sense lacking In all the higher
mammals. .t
The engineers, taking their cue from
the flies, have replaced the halteres with
q rapidly vibrating tuning fork which
is extremely sensitive TO rotational
change.
Future Developments" says the
British report. may bring about COM
plete replacement Of gyroscopic In
struments. Once it becomes possible to
detect rotation in this way 1t should be
possible to maintain 1t at any desired
value"