214
Population—from the Managing Director of the Tramway Company, based
on average tramway receipts for several years, checked with information published
by the Bombay Chamber of Commerce. These returns, from independent
sources confirmed by the Plague Committee's observations, may be taken as fairly
correct.
Daily mortality—from cemetery returns of the Municipal Health Department.
Normal mortality—the average of the five years previous to the outbreak of the
P iague from the returns in the Government Gazette.
The red figures at the top of the chart are the total deaths from all causes during
each month, and the red figures below are fche total deaths from Plague; deaths from
cholera are shown in black figures under the Plague totals.
Plague
deaths.
The total number of deaths from Plague has been arrived at in the following
manner :—
The total weekly average number of deaths during the five years previous to the
Plague has been deducted from the total deaths from all causes for the week, and
the remainder taken as the number of deaths due to Plague, deaths from cholera being
shown separately. But owing to the decrease of population, there must be added,
in order to arrive at a true conception of the increased mortality, a figure bearing
the same proportion to the recorded deaths as the calculated actual population bears
to the normal population of 850,000. This calculation has been made, and the
figure or number to be added is given in red figures above the numbers for estimated
deaths from Plague by months, entered at the bottom of the chart.
Object of com-
pilation of
chart.
The object of the compilation of this chart was to establish the truth or otherwise
of some of the theories freely advanced. regarding the definite influence of tempera-
ture, humidity, wind and clouds on mortality. No more definite connection is evi-
dent from the records than was the case last year (see marginal quotation from
last year's report), and most, if not all, of these theories must for the present be aban-
doned.
Northerly and easterly winds, which are always dry, seem generally to have
had an unfavourable influence, often immediately so, on the mortality, e.g., after
October, i.e., from November to near the end of March (when the humidity was only
on four days above 80 and generally between 60 and 70 and while easterly winds
prevailed) the mortality increased irregularly but more or less steadily ; and in
particular cases, e.g., on 8th and 9th February and on the 2nd March, when high
winds were accompanied by a fall in the humidity, there were immediate increases in
the deaths as shown in the chart.
There has not, however, been a sufficiently consistent sequence to make
any generalisation possible, and as a matter of fact, in order to give the elements a
fair chance, all Plague measures should be abandoned, for it cannot be doubted that
the measures that have been adopted have had the effect of diminishing tho extent of
the pest. The degree of sanitary efficiency is also a disturbing factor.
Adventof the
yains.
Tho records of 1897 show that the advent of the rains may be looked to with the
confidence that this year again the Plague death returns will be very low durino- the
monsGon ; and the returns for April make this assurance doubly sure.