Daily press. [volume] (Newport News, Va.) 1896-current, 1910-05-06
The Detection Of Blood Guilt.

People often wonder why 1t is that
experts, when giving evidence in
court, can so confidently affirm that
la certain substance removed from
clothes. weapons, and so on con-
sists of blood, alohtugh the suspect
ed parties declare it to be rust or red
paint. The determination of the
truth is, however, a matter of simple
preparation and microscopical obser-
walton which is absolutely infallible.
for reasons which | will give.
The reader probable learnt at
school that all human blood consists
lof two kinds of dense-packed glob-
Jules invisible to the naked eye. called
corpuscles, white and red, floating or
suspended in liquid. / doubt wheth-
/ er enc person in million-apart
from those who study such topics
has any real idea of the minuteness
of these objects. 1t is useless to say.
for instance, that ten million OF the
red corpuecles will cover a square
inch if laid out quite fiat.
1t is the function of the white cor
puscles to consume the bacteria and
bacilli that enter the blood, and they
are actually alive. The red discs con-
tain the iron of blood. This match
enables US to proceed with under
standing.
/ squeez a mere drop from
needleprick in my finger on to a slide.
At first all the globules and discs
are fairly well defined. though it is
! usual to add drop of water, or
chemical solution, to separate them
| and render them clearer. Slowly the
Idrop stiffens, the firmnese commenc-
ing at the edge (Which is paler than
elsewhere) and proceedings inwards.
Within short time 1t has wholly con-
gealed. The edge is family frilled,
while tlft-like, darker lines, the fibrin.
are observable near 1t. The lengths
OF the tufts increase toward the cen
ter of the spot, in the vincinity Of
which their are comparatively large
cracks dividing the film into plates
like those on a tortoise's back No
beads are then present This fea-
ture of itself affords q good clue TO
tine cieverer analysis IL the substance
is not too old. | wait till next day
before making the tests.
The died blood Is eventually Ioos-
ened with a thin. sharp knife blade,
and comes away ike a fieck OF india
rubber of leather. OF similar resistant
!yct pljsbIe stuff. I detsch all except
the portion 70 be tested. Then I let
fall a drop % glacial scetic acid on
TO the dried fake. add tiny speck
iof common salt, and gently warm the
mixture. Upon replacing Il beneath
the microscope the liquor coos and
ievsporstes. and their strangely
Isprings into view q mass Of red
brown crystals. OF maybe scattered
lone. having definite characteristic
,shapcs. The chemical reactions have
been % a very curious Kind. Before
the appearance Of the crystals bub-
bles Of gas. ETC. emerge from be
tween the cracks separating the mt
mute plates. and burst in due course
iThcn the edges Of the plates become
faintcr and fainter until all red tint
Is absorbed. and the Crystals com
mepce 70 appear AZ various points
The substance forming these crys
tais. composed Of chlorine from the
ISsit and extrsctions from the blood
!combired. Is known a. hscmin. Of
Ichioride Of hsemstiu- The crystals
lvill undergo another chance int
brown irregular particles u an aikaiI
tsuch az soda. Is ADDED.
| n has not only 10 be detsrmiact