Medical Jurisprudence And Toxicology

46 MEDICAL JURISPRUDENCE

Galton System.—This system, which is also known as dactylography,
consists in taking the impressions of the bulbs of the fingers and thumbs with
printer's ink on an unglazed white paper and then examining them with a
magnifying lens. It is based on the principle that the individual peculiarities
of the patterns formed by the arrangement and distribution of the papillary
ridges on the finger tips are absolutely constant and persist throughout life,
from infancy to old age, and that the patterns of no two hands resemble
each other. It has been estimated that the chances of two persons having
identical finger impressions is about one in sixty-four thousand millions.

The following case46 well illustrates the fact that it is possible for any
two persons to bear striking points of resemblance on the body, but it is
never possible for them to have identical finger impressions: —

In 1917, Professor Canella of Milan, while serving the Army in Macedonia, was
reported missing and was never heard of again. In 1924, a man suffering from loss of
memory was admitted into a Piedmont asylum and he remained there for two years.
Afterwards the wife and the daughter of the professor unhesitatingly identified him
as the professor, as he bore remarkable external resemblance. He was at once taken to
Milan, where all the friends of the professor at once recognized him. By degrees he
appeared to recover his memory* and then asserted that he was indeed the lost professor,
and purported to recall many incidents which had happened in the latter's career. All
seemed well, but suddenly there fell a bolt from the blue. A woman appeared on the
scene and identified him as her husband, Bruneira, who had absconded three years ago
after a career of crime. The family and acquaintances of Bruneira, one and all, likewise
identified him. He was examined and found to possess certain marks on the body,
which, however, curiously enough were alleged by both parties of relatives to be lifelong
marks of Canella and Bruneira respectively. The Italian Police produced the finger
prints of Bruneira which were alleged to be identical with those of the man whose
identity was in dispute.

The ridges on the fingers and hands are studded with microscopic pores,
which are the mouths of the ducts of the sweat glands situated below the
epidermis. These pores may be used for personal identification, as they are
permanent and immutable during life and vary in size, shape, position, extent
and number over a given length of the ridges in each individual. This method
of identification by examining the pores is known a^oroscogy, and is of the
greatest value when a small fragment of a finger impressionrior an impression
of a part of a palm is available for comparison.

Before taking the impressions the fingers should be thoroughly washed,
and rubbed clean and dry, as the slightest perspiration will cause blotches and
blur the print. It should be remembered that the finger prints of lepej^-
should, on no account, be taken, while those of persons suffering from infec-
tious or contagious diseases should not be taken until they have completely
recovered.

Fingers smeared with blood, grease, dirt or slight perspiration may leave
their impressions on weapons, clothing, glass panes, utensils, furniture, etc.,
hence considerable care should be taken in handling such articles during the
investigation of a crime, and any articles found to possess such prints should
be preserved for further examination.

Finger impressions are either rolled or plain. A rolled impression is obtained
by first inking the bulb surface of the finger or thumb between the nail boundaries
and then placing the inked finger or thumb on the paper so that the plane of the nail
is at right angles to the plane of the paper. The finger or thumb is then pressed lightly
on the paper and turned over so that the bulb surface which originally faced to the
left, faces to the right and vice versa, the plane of the nail being again at right angles
to the paper. A plain impression is obtained by lightly pressing the inked bulb surface
of the finger or thumb upon the paper without any turning movement.

In a plain impression the whole contour of the pattern does not appear, whereas
in a rolled impression the whole pattern is delineated. It is, therefore, easier to deter-
mine the type of pattern from a rolled impression, and its greater surface enables the
expert to select a larger number of points for comparison.

46. Times, March 1, 1927; 28 Criminal Law Jour., 1927, p. 62.