Deck. — Influence of Temperature on Infant Mortality. xxxvii 



from cerebral aflfections, sncli 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-j)neumonia, occurred with 

 decidedly greater frequency during the winter months. I have laid before you 

 a diagram (PL XIII. , 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 occurred 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 diarrhoea, 

 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 XIII., 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, ]^ew 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 sequelae 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 



