MEDICAL ASPECTS OF PLAGUE.]
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The official returns of deaths from plague were for various reasons not very accurate.
À fairly correct estimate of the mortality can be obtained, however, by taking as plague
mortality the difference between the weekly mortality and the mean of the corresponding
weeks during the preceding five years, as there was no other unusual cause of sickness
present.
It must be remembered that the average weekly mortality during the preceding five
years was taken on a population of 800,000, and that owing to the exodus which occurred after
the outbreak of the epidemic the population was reduced by from a fourth to a third of that
number. The true incidence of the disease was consequently considerably heavier during the
later weeks than shown in the table, and this error was a gradually increasing one growing
with the decrease of the population.
It has been stated that in other places outbreaks were often preceded by the
appearance of cases of painless buboes unaccompanied by vomiting, fever, headache or other
symptoms of plague, but this was not observed in Bombay.
It may here be noted that the great difficulty which arises in tracing the mode of infection
and the course of plague, as compared with the other more common infectious diseases, is
due to two facts—viz., that animals such as rats readily contract and afterwards spread
the disease, and that the microbe is capable of thriving and multiplying outside the animal body,
as is seen, for example, when it is cultivated in broth or· on ghee. It is evident that infection
may be carried by rats to persons who have never been brought into contact with plague
patients, nor with persons visiting plague patients, and whose food and clothing could not
have been contaminated in any other way. On the other hand, the germs may be conveyed
by persons who are themselves insusceptible to plague, and having grown and multiplied on
suitable media and under favourable conditions, may infect large numbers of people who have
never come into contact with plague patients, their attendants or plague-stricken rats.
The development of plague in an epidemic form was believed by many persons to be due
to rotten grain which had been buried underground, and, it was thought by some, infected
with plague germs. Had rotten or diseased grain been sold as food (and there was no evidence
that this took place), it would in all probability have given rise to digestive disorders, and in so
far have predisposed to plague ; but if the grain had been infected with plague bacilli, the
disease would have appeared in several localities simultaneously, wherever the infected grain
Lad been eaten. It is impossible to believe too that large stores of infected grain could have
been sold without giving rise to an outbreak of disease among grain-sellers throughout
Bombay. It is well known that this spreading of the disease far and wide among grain-dealers
did not occur, and the 54 grain and flour-sellers, millers, and grain-parchers who died from
plague between the months of September 1896 and January 1807, died principally in infected
localities in the neighbourhood of the Docks, where the disease first appeared, but did not
themselves form centres from which the disease spread in unaffected districts.
The epidemic was observed to increase notably during the cold season and to decline
during the hot weather. This increase during the cold months was probably due, to a great
extent, to the sick and healthy occupying the same rooms during the day and sleeping
together at night, and also to the depressing effects of cold. During the war in months the
poor live under much more sanitary conditions than in the cold season.
The influence of animals in spreading the disease was, with the exception of rats,
probably inappreciable. A searching inquiry at Damaun, where there were great numbers
of pigs at large in the streets, elicited no evidence of a single death, or even of an appear-
ance of sickness among pigs, although an exceptionally severe epidemic of plague had visited
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