223:
Seasonal changes.
Both the local conditions and the conditions affecting the healthy and sick ap-
pear to be modified by seasonal changes, commencing in the cool weather of February,
attaining its height in May, the epidemic commenced to decline with the decline of
the hot season in June.
Incubation.
It .seems next to impossible to furnish any precise data with respect to the actual
period of incubation, but there has been sufficient evidence to indicate that in the large
majority of cases it is short. Assuming the theory of direct inoculation to be correct, it
is probable that the period varies from a few hours to one or two days. By other
methods it may extend to a maximum of eight days, and the average might be set
down at five.
Symptoms.
Phlegmonous condi-
tion of the skin.
Perhaps the most striking point in connection with the symptoms of the disease
is that the onset and progress differ enormously in different cases. Most commonly
after a period of lassitude, headache, aching in the limbs and loins, the fever com-
mences, and either concurrently with this or from the second to the fourth day, tender-
ness followed by buboes in the groins, axillæ, or angles of the jaws. The febrile con-
dition is usually acute in the early stages, often accompanied by severe headache, and
in the worst cases by delirium and stupor. In some of these latter the whole toxic
effect of the disease seems to localise itself in the central nervous system, producing the
gravest symptoms—the suffused conjunctivæ, the hesitating drunken speech, the in
ability to comprehend or answer questions, the feeble pulse, the extreme prostration—·
all marked indications of the severity of the attack. In less grave conditions the
tongue is white and thickly coated, the teeth and gums covered with sordes, and the
thirst intense. The swelling of the glands increases and is accompanied by tenderness,
sometimes followed by acute pain. In several cases a condition has been noted in
which no gland could be detected, but a thick puffy ædematous condition of the skin
over the situation of the gland in the axillae especially, which rapidly spreads to the
adjoining parts, in one case extending on the right side over the whole of the chest as
low as the last rib, across the front of the chest to the tip of the left shoulder, and over
the right shoulder into the neck as high as the lower jaw. All these cases proved
rapidly fatal. The pulse runs quickly up to 120 to 130. The temperature varies from
102° in mild, to 107° in the severest, form. The end of the fever is commonly marked
by a sudden fall of temperature often as low as 97° or 96° F. In the early stages nausea
and bilious vomiting are very common. The urine commonly contains albumen, and
there have been several cases of retention, and two of complete suppression, In the
later stages the fœces are passed involuntarily.
Local signs.
Of the local signs the appearance of buboes, or rather tenderness, not infrequently
precedes the symptoms of general disturbance. In some cases they are first observed
within twelve hours after the fever has set in ; in other and more numerous cases they
show themselves on the second, third and fourth day of the attack. The enlarged
glands forming buboes are rarely numerous (vide Statistics), and of a group only one
is, as a rule, enlarged, attaining the size of a cocoanut, whilst others are but little en-
larged. Suppuration rarely occurs in fatal cases, the toxic poison seldom admitting of
sufficient time to reach that stage.
Petœchiæ distributed generally over the body are often observed usually preced-
ing a fatal issue.
Necrosis of skin.
Pustules commencing as sanguinious bubo varying in size from a nut to a hen's
egg, followed by suppuration and necrosis of skin.
Physiognomy.
Plague has a special physiognomy, having nothing in common with other diseases.
The eyes are suffused and retracted within the orbits, the aspect is haggard and