|
158 TRIAL OF JOHN W. WEBSTER.
tions having spots upon them, similar to those now remaining. I have
satisfied myself, that these spots, which I examined, were spots of blood.
The right slipper had the blood on it; and, on the soles of both slippers,
was a substance resembling Venetian-red.
The pantaloons are marked with the name, " Dr. Webster." I cut
pieces from them, on which were spots; and these were shown, by the
microscope, to be blood.* There were quite a number of these spots,
now visible, on the outside of the bottom of the left leg. The drops of
blood do not appear to have fallen from any great height; say, as much as
three or four feet, or from the height of the hand, above the place where
they were found. If they had fallen from that height, upon a vertical
surface, they would have had an elongated form. My impression is,
therefore, that they must have come upon the pantaloons, laterally, or
spattered up, or have fallen from a very short distance above. The only
other marks of blood, which I discovered, were a. few spots, on a piece
of white paper, said to have been picked up in the private room.
[Professor Wyman was now requested to produce his catalogue of
the bones, and give such general explanation of its details, with the
* (By the kindness of Professor Wyman, we have been furnished with the
following brief note on the microscopic test of the presence of blood, which
we are glad to put in a permanent shape upon our pages.-Ed.)
NOTE.-When blood exists, in large quantities, upon furniture, clothing,
&c., a general inspection, with the aid of chemistry, will determine its
pres-
ence with sufficient accuracy. It is, however, not infrequently found in too
small quantities, for chemical analysis; and it has happened, that the
state-
ment of a police-officer, or other non-professional spectator, has been
admitted.
as evidence, that the stains, in question, were those of blood, when the
bare
announcement, by a physician, even, should be taken with the greatest cau-
tion. There are abundant instances, In the treatises on Medical
Jurisprudence,
of unfounded charges, and unjustifiable arrrests having been made, in con-
sequence of an error at the outset, as to the true nature of stains, assumed
to be blood. It is, therefore, in the highest degree important, that
examina-
tions should be conducted with the great, st care, and that another s'gn,
than color, (which has been abundantly proved to be fallacious,) should be
obtained.
Recently-drawn blood, when placed under the microscope, is at once recog-
nized by the prescence of vast numbers of flattened discs, (commonly, though
inaccurately, designated as "blood-globules,") of a red color, with a s'ngle
central spot; interspersed among which, may be seen, in far lesser numbers,
compared with the discs themselves, rounded colorless globules, containing,
each. three or four central granules. These last are known to phys'ologists
as " lymph-corpuscles," or ' lymph-globules," proper.
If a drop of blood be dried upon a piece of glass, painted wcod, or other
surface, and a small portion, (a thin scale, scraped off with a knife, is
the
most desirable form,) be placed under the microscope, and water added to it,
it soon becomes softened, very slightly tinges the water around it with a
pale
reddish color, and becomes more or less transparent, according to its thick-
ness. After a careful inspection, the observer will seldom be able to find
any traces of blood-discs; but transparent, colorless. spots will be seen
scat-
tered through the mass, which, with a high power, (say 800 diameters,) may
be
seen to have a globular form, and to contain granules,-usually three or
four.
These are the lymph-corpuscles.
If a drop of blood be rubbed on a piece of glass, as by drawing'a bloody
finger across it, so that the discs are deposited in a single layer, and
then
allowed to dry, (they are readily recognized, even in the dried state; but
when allowe~3 to dry in masses. I have failed to determine their presence.
The
lymph-globules, on the contrary, may be softened out, after they have been
dried for months, and their characteristic marks readily obtained. I have
examined blood, which has been dried for six months, and have found it
easy to detect them. It is not improbable, that they may be detected, after
the lapse of years, if the blood shall have been preserved dry, so as to
pre-
vent decomposition.
The evidence, that the stains on the pantaloons and slippers of Pro-
fessor Webster, were of blood, was derived wholly from the microscope.
And the presence of lymph-corpuscles, combined with the color, and other,
and less characteristic, microscopic appearances of the blood, was the
basis of the opinion given at the trial.
While the presence of lymph-corpuscles, combined with the ordinary
and more obvious appearances of blood, is regarded as the diagnostic sign
of Blood, yet it should never be lost sight of, that it does not give an
abso-
lute sign, that the blood is that of the human body. The blood of some ani-
mals, so closely resembles that of man, in its microscopic characters,
that, as
yet, no positive means exist by which they may be distinguished. The opin-
ion, that a stain of blood, in question, is human, or animal, must rest upon
probabilities. J_ W.
|
