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In the first case we have the most common of creatures parasitic on human trade and
industry and finding a home in the insanitary surroundings of certain parts of Bombay by
their secretions, by their droppings, by their deaths and in the course of their movements
infecting floors, dress, articles of food as well as by their parasites. In such
a case as this the only way to deal with them is to trap them as other methods
of destruction such as poisoning them or fumigating their runs or the drains or sewers of
a town simply extends the area of their infection by driving them from one location to
another until they have over-run the whole town sowing a crop of plague in their train.
This state of things appears to me to be brought about in Bombay city each year, the
determining cause which decides the rat migration which takes place during an epidemic
from one area to another being fear or panic on the part of the rats—panic which drives
them to seek healthier surroundings where they won't see their brethren dying in vast
numbers. In this way the whole of the Island becomes infected every year.
Where you have primary human infection it appears to me to be even more necessary
to drive rats from the theatre of infection, for you thereby prevent infection from man to
rat—a mode of infection easily understood—when we consider that the rat is parasitic on
human kind to the extent of his food and lodging and when at the same time it is borne in
mind that all the secretions of the human body (with the exception of sweat) have been
shown to contain plague bacilli. In this way you eliminate an important factor in the spread
of the disease. In this connection the hospital system where you can by vigorous action keep
the immediate area round a hospital clear of these "carriers of infection " appears to tend
towards a diminution in the spread of the disease ; that is, if the hospital is under proper
control and so situate as to render it an easy matter to keep it clear of rats.
A consideration of the foregoing facts would appear to lead one to the conclusion that
now when plague is practically non-existent in Bombay is the time for a most vigorous
crusade against these rodents which constitute the greatest agency of all in the spread of
plague, as now we have them in a healthy condition (and when their migration will result in
no harm), when the driving of an enormous number of them out of Bombay by fumigating
their habitations, or their destruction by poison (with the almost necessarily certain migration
following on such action) will considerably curtail their powers of future harm in proportion
to the diminution of their numbers in Bombay city. Such action taken now and kept
up continuously until the start of the rat epidemic, which one would look for next November
or so, will, I feel sure, do much towards limiting the invasion of plague in Bombay city
next year.
To prevent the stocking of Bombay sewers, gullies, drains, &c., with a new rodent
population from the ships in Bombay Harbour, each ship berthing in Bombay Docks should
when discharged of cargo be taken out into the stream and there thoroughly fumigated so
as to destroy every rat on board.
This measure would be of special importance when
plague was epidemic in Bombay for it is then that an invasion of healthy rats from the
ships to infected Bombay would be of special danger. The continuous driving out or
destruction of rats up to the start of the next rat infection and the prevention of the
re-stocking of Bombay with rats from ships in Bombay Docks will, I feel sure, be a
measure which will bring great good in its train. It will further be remembered that such a
measure is a preventive one and its results ought to bear out the old adage that
"prevention is better than cure."
Dr. O'Brien, Special Medical Officer, E Ward, reports as follows :—
The disinfectants used in this ward are Perchloride of Mercury and Phenyle. It is
claimed for the former that it is one of the most powerful of disinfectants known ; and that a
solution of 1 in 5,000 is capable of destroying plague germs after one minute's contact. The
strength of the solution used in this Ward stands at 1 in 950 ; so that it would appear un-
likely that the strength of the solution is faulty. This great augmentation in strength was
rendered necessary owing to the large amount of organic and mineral matter present in cow-
dung. In the Agricultural Ledger No. 3 of 1894 Voelker and Ledger showed a percentage
composition of 35.7 organic, 27.7 mineral matter, and 36.6 moisture, in six samples
analyses of Indian cattle dung.