THE RATES OF MORTALITY. 67 



the seasons. Thus the mean death-rate during the five 

 years 



1854-58 was 1*296, 



1859-63 „ 1-528, 



1864-68 „ 1778, 



1869-73 " 2-040. 

 Comparing the rate during the last five years with that 

 during the first five, the increase is 57-4 per cent ! 



We have seen that the increase in the mortality from 

 small-pox was relatively much less among infants and young 

 children than among adults; but with bronchitis the reverse 

 of this took place. Thus in the five years 1854-58 the deaths 

 of males under one year of age were 21-2 per cent, of the 

 total deaths at all ages, and under five years 36-3 ; in the 

 five years 1869-73 the numbers were respectively 25-9 

 and 41-2. It is remarkable, however, that between the 

 ages of ten and twenty-five there was a slight decrease, so 

 that the curve representing the variations in the mortality 

 at different ages from bronchitis has two well-marked max- 

 ima — one at ages under one year, and the other between 

 the ages of fifty-five and sixty-five. The increase at ages 

 under one year amounted to 49-7 per cent., and at ages 

 between fifty-five and sixty-five it was 35-6 per cent. Du- 

 ring the year 1873, out of every 19 deaths from all causes, 

 two were due to bronchitis alone. In the seven years 

 1848-54 the proportion was two deaths from bronchitis 

 out of every 47 from all causes. 



I have already remarked that the increased mortality 

 from bronchitis cannot be attributed to changes in the 

 character of the seasons. It is, however, due to some 

 cause which affects the entire population of the kingdom, 

 both male and female, since I find that the increase has 

 been general and not confined to smoky towns and manu- 

 facturing districts, as will be seen from the following com- 



r2 



