Drcx.—Influence of Temperature on Infant Mortality. XXXVii 
from cerebral affections, such as convulsions, congestion of the brain, and 
tubercular meningitis, took place, as far as the records of this small number 
show, with about equal frequency at all periods of the year. 
The fifty-eight deaths that took place from affections of the respiratory 
organs, such as croup, bronchitis, and broncho-pneumonia, occurred with 
decidedly greater frequency during the winter months. I have laid before you 
a diagram (Pl. XIIL, 2.) which I have drawn up with the desire to show 
the variations in the mean, maximum, and minimum temperature for each 
month during the years above mentioned, and the shaded spaces below show 
the number of deaths that eccurred from diseases of the respiratory organs 
during those several months. It will be noticed that they occurred principally 
during, or just after, the depression of the line of temperature in the winter 
months, during August, September, and October, in 1870, and during June 
and July in the year 1871. 
The 103 deaths that took place from intestinal disorders, such as diarrhea, 
dysentery, and cholera infantum, being nearly twice as many as the deaths 
from respiratory diseases, and three times as numerous as those from brain 
affections, show that this class of disorders is the one the most serious to 
infant life. They occurred, as may be seen from Pl. XII., 1, during the 
hot summer weather, or they followed it very closely. They occurred princi- 
pally during February and March in the year 1871, and during January, 
February, March, and April in the year 1872; the number of cases in each 
month respectively being indicated by the shaded spaces in the lower part 
of the diagram. 
It will at once be noticed on looking at the curves of temperature in that 
diagram that the summer of 1871-72 was much hotter than the summer of 
1870-71, and the greater rate of infant mortality is visible at once on 
comparing the shaded spaces referring to those summers. It is to the 
influence of high temperature in increasing the rate of infant mortality from 
these affections that I wish especially to draw your attention. The same rule 
holds good here which has been found to apply in London, New York, and 
other places, that the higher the rate of the summer temperature the greater 
the rate of infant mortality that is observed from intestinal affections. 
And I would observe that the increased temperature itself, rather than the 
insanitary sequel to which it gives rise (although, no doubt, they are in some 
measure accountable for the result) seems to be the chief factor at work among 
the causes that combine together to produce this increased mortality. The 
case is different when we consider the increased rate of mortality from disease 
of the respiratory organs during the winter months. Cold weather is often 
most healthy weather. There may be severe cold, cold weather such as that 
we experienced during the past winter, when the snow lay upon the ground 
