100
Twenty-four post-mortems were made. In 18 the disease was confirmed by the
subsequent culture of microbes ; in 2 there was some doubt ; in the remaining 4
no bacilli were discovered. This result does not, in my opinion, prove these 4
cases not to have been plague. It is known for a fact that, if a case progresses
far enough, the microbes undergo dissolution and disappear. Indeed in the bubonic
form their disappearance might be said to begin with the appearance of suppuration,
and it is an uncommon event to find them in the pus of a suppurated bubo, unless
the suppuration has been very active. Even in a patient approaching convalescence
the physiological change caused in the blood by this toxine appears sufficient to
produce the death of the bacilli which originated it ; and in this way we may have
a death from plague due to exhaustion or syncope at a period when the bacilli have
undergone complete dissolution ; and this alteration in the blood is an argument
against the recurrence of the disease in those who have recovered, since it
has been demonstrated by experiment that the germ immediately dies, or
becomes permanently incapable of culturing itself in the serum obtained from
such persons. Or at least it can be reasonably inferred that, unless the epidemic
is extensively prolonged, a person once affected and cured can hardly become
reinfected, although in every form of infectious fever there are exceptions
to the rule. The special pathologists belonging to the various medical missions
will, no doubt, deal with the pathological detail of the disease in a more exhaustive
and minute manner than my observations permit me to do. There appeared a
complete deficiency of tone throughout the whole muscular structure.
In the cavity of the cranium no special morbid appearance was noted. The brain
seemed a little softer, and there was a perceptible injection of the medullary vessels or
substances. In some instances the nerve-cells under the microscope had appeared
slightly atrophied. The covering of the brain had not undergone any change.
On opening the body, the only definite change was congestion of the mucous
membranes and    their  apparent  softening,   especially  of  the  stomach  and  small
intestines.    The heart appeared flabby and soft, the pericardium distended, contained
a larger quantity of fluid than usual, and on its inner surface were-but not in all
cases-congestive  specklings.    The orifice of the right ventricle  was  dilated, as at
times were the ventricles also.   The stomach was covered with yellowish slimy fluid of
a mucoid nature, and so were the intestines, which were in a condition of distension.
The liver and spleen were generally engorged and of a dark colour and perhaps en-
larged.  Microscopically the pancreas presented no unusual aspect, though they might
occasionally be increased in size.   The kidneys may be enlarged to a variable extent,
their surface containing specks of extravasation and the capsules  soft  and  easily
torn  off.    Internally they are usually congested, and there may be hæmorrhage
into the pelvis.    Indeed, broadly speaking, beyond an engorgement and more or less
extravasation of the internal viscera, the pathological changes are entirely confined to
direct lesion, whether it be in the gland or lungs.
The gland or glands affected are enlarged and seem   as if  they have been
bruised or contused about their integument.    There is a bloody effusion immediately
surrounding them.    The lymphatic tissue,   or cellular membrane,   are inflamed.
The glands  range in   size   beyond that of a  walnut, and   are generally livid,   and
hard  unless a tendency to suppuration has set in.    Their interior may be engorged
and presents points of necrosis.    The abdominal and pulmonary glands may also
increased in size, chainlike, and surrounded by hæmorrhagic effusions.
I have already mentioned the appearance of the pneumonic form in a
previous part of this paper. It is only necessary to mention that in one
of the post-mortems the glands at the base and behind the tongue were found