nd in
December of the same year there was a rapid fall of temperature, when the
number of deaths from acute diseases of the lungs rose from 297 to 358,
350, 387, 541, 553, and 389 in the respective weeks. From November 29 to
December 9 the sun was seen only on two days for 41/2 hours, and from
December 9 to the 18th also on two other days for less than 4 hours,
making the total amount of sunshine 8.1 hours only in 20 days. In January
and February the excess of weekly mortality from all diseases reached the
large number of 504 deaths; in December it was less, the fogs not having
been so dense, but the excess equaled 246 deaths per week.

The relations between a high summer temperature and excessive mortality
from diarrhoea have long been well known, but the immediate cause of the
disease as an epidemic is not known. Summer diarrhoea prevails to a greater
extent in certain localities, notably in Leicester (and has done so for
years); and the cause has been carefully sought for, but has not been
found out. Recent researches, however, point to a kind of bacillus as the
immediate cause, as it has been found in the air of water-closets, in the
traps under the pans, and in the discharges from infants and young
children. In order to indicate more readily how intimately the mortality
from diarrhoea depends on temperature, I now lay before you a table showing
the mean temperature for ten weeks in summer, of seven cold and hot
summers, the temperature of Thames water, and the death-rates of infants
under one year per million population of London:

_London.--Deaths under 1 Year, in July, August, and part of
September, from Diarrhoea per 1,000,000 Population Living
at all Ages, arranged in the Order of Mortality._

Age 0-1 year.
Mean Temperature Deaths from Diarrhoea
Years. temperature, of Thames per 1,000,000
10 weeks. water. population living at
all ages.
1860 58.1 deg. 60.6 deg. 151
1862 59.0 62.0 189
1879 58.7 60.7 228
1877 61.2 63.3 347
1874 61.7 63.8 447
1878 63.7 64.1 576
1876 64.4 64.9 643

As may be seen, the deaths of infants under 1 year of age from diarrhoea
per 1,000,000 population was only 151; while th