3
tially a house disease and in Asia more particularly a floor one, owing to the filthy
mode of living of the ordinary Asiatic. Once having reached a favourable ground,
the increase and multiplication is only limited by the extent and nature of the
pabulum. Moist organic matter is favourable to its existence, but it is unable
to withstand desiccation, and this with a moderate amount of heat up to 58-65° C.
causes its complete annihilation in the course of a few hours.
The causes that are favourable to the disease are conditions which invari-
ably prevail in the quarters of the poor, viz., dirt, overcrowding with want of
ventilation and light. Dirt seems most essential, for without it the bacillus dies
of inanition.
Want of ventilation and light are considerable factors in impeding that
desiccation so inimical to the life of the germ. Inoculation seems undoubtedly
the means by which infection takes place, whether through mucous membrane
or by skin abrasion. There seems little doubt that the naked feet of the native
predisposes to the risk of contracting the disease.
This is too long a subject to fully discuss at present in all its clinical and
pathological bearing.
The effect of Density of Population on the Progress of the
Disease in Poona.
As might be supposed, the density of the population had considerable effect
on the spread and progress of the disease in Poona. In the three districts of
Nána, Ganesh and Rawiwár, which contain the greatest number of inhabitants
per square yard, the incidence of the epidemic was most striking ; in fact, the
table of density and mortality of the various peths makes almost a sliding scale,
which brings this point out very clearly :
Peth.
Rawiwár ... ... ...
Ganesh ... ... ...
Nána ... ... ...
Total
population.
10,674
4,078
5,237
Square yards
per head.
30.44
38.00
37.23
Percentage mor-
tality, December
1896 to May 1897.
5.04
6.06
3.03
The first case of plague occurred in Nihal Peth, which is also one of the
dirtiest and which was also responsible for the last case up to the time of writing.
Among the outskirts of the various Peths there was little plague, the houses
here being far apart, among gardens and showing no overcrowding, whereas
among the densely populated parts it was always noticeable how many houses
showed the " plague mark." In the suburban limits there was very little plague,
and it was seen that on the people fleeing the city and betaking themselves to
the surrounding country encamping out in the fields, there was no increase of
the plague among them ; nor did the adjacent villages suffer much from the
disease. The cases which they removed died there ; but the people themselves
remained practically free from plague : neither did they seem to again introduce
it on their return to the city. The effect of density on mortality may be
accounted for by various influences which are the usual concomitants of over-
crowding, viz., dirt and the want of ventilation.
These three factors :—
(a) Overcrowding,
(b) Dirt,
(c) Want of ventilation,
have all direct bearing on the disease, and it is their combined influence which
so much effects the malady.
By overcrowding and want of sufficient ventilation, the vitality of the
people occupying such insanitary houses, is considerably diminished and they
fall easy victims on the attack of the disease.
With diminished cubic space the contract and association of the occupants
is greater than in dwellings of more liberal dimensions.