70
[CHAP. II.
the town. Sheep, goats, torses and cows were unaffected. There was evidence (post-mortem)
of a dog having been affected, but none that cats contracted the disease. Birds were not
at all affected.
In the epidemic at Hardwar, monkeys were infected and died in considerable numbers,
The grey monkey is very susceptible to plague and rarely recovers ; the brown monkey is
much less severely affected.
The influence of ants and bugs in spreading the disease was considered by Mr. Hankin
to be unimportant.
All observers up to the present time have connected the occurrence and diffusion of the
disease with want and filth, and there seems to be no doubt that these factors do favour it
in so far as they lower the general health and diminish natural immunity. But it will be
seen that filth per se has but little influence, from the fact that there occurred in the House
of Correction, Byculla, where cleanliness is brought as nearly to perfection as is attainable,
an outbreak which exceeded in severity that in any of the filthy chawls and tenements around.
There were 345 prisoners confined in this jail when plague broke out there on the 23rd
January 1897 ; the outbreak lasted for 15 days, and in that time 33 prisoners were attacked,
17 of whom died. It is a significant fact, too, in this connection, that out of 1,579 patients
treated at the Arthur Road and Parel Hospitals there were only 16 sweepers, and that the
halalcores who remove the night-soil from the houses, and who form probably the dirtiest
portion of the population, were notably free from plague. It is true they are a strong well-
nourished class, of whom only the fittest have survived, and they are highly paid and live
well.
The predisposing causes were mainly those leading to a lower state of vitality, and
which consequently lessened the natural resistance of the individual to infection. In this
way, as above mentioned, the long-continued and exceptionally hot season of 1896, the un-
usually heavy rainfall which followed, and which confined the poor constantly in their over-
crowded and insanitary dwellings, and the great heat which succeeded the rains, were power-
ful factors in lowering vitality. Then came scarcity due to dearness of food. During the
cold season the unhealthy condition of chawls (native flats) and houses in the city was ren-
dered worse by overcrowding, the inmates being unable to sleep and work in the open, as
large numbers of them are accustomed to do during the warmer months. Indeed, the effect
of cold alone on the feeble and on those who are insufficiently clothed, as already mentioned,
is a powerful factor in lessening resistance to infection.
The largest number of admissions to hospital occurred between the ages of 20 and
30 years. At the Arthur Road Hospital, Bombay, out of 1,275 admissions, 445 or 34 . 9 per
cent, occurred between the ages of 20 and 30 years; 291 or 22 . 8 per cent, between 10 and 20
years ; and 255 or 20 per cent. between 30 and 40 years.
In the Poona Plague Hospital, out of 1,130 admissions, 263 or 23 . 27 per cent, occurred
between the ages of 20 and 30 ; 137 or 20 . 97 per cent. between the ages of 10 and 20 years;
and 197 or 17 . 43 per cent. between the ages of 30 and 40.
A constant source of error in these statistics is that the ages of those admitted are
seldom or never exactly known, consequently those given are only approximate. Another
source of error is that in young children death from plague frequently occurs before the
nature at the disease is recognised, so they are not admitted into the plague hospitals. In
the case of children, however, the very small number of admissions (vide Tables I. and II.)
is no doubt partly due to the smaller number exposed to infection, as the exodus which took