506 Effects of Epidemics on Registers of Bk. ii. 



the observation is just, comparing similar ages 

 together. But, under the most favourable cir- 

 cumstances, infants under three years are more 

 subject to death than at other ages; and the ex- 

 traordinary proportion of children which usually 

 follows a very great mortality, counterbalances at 

 first the natural healthiness of the period, and pre- 

 vents it from making much difference in the ge- 

 neral mortality. 



If we divide the population of Prussia after the 

 plague, by the number of deaths in the year 1711, 

 it will appear, that the mortality was nearly 1 in 

 31, and was therefore increased rather than di- 

 minished, owing to the prodigious number of 

 children born in that year. But this greater 

 mortality would certainly cease, as soon as these 

 children began to rise into the firmer stages of 

 life, and then probably Sussmilch's observations 

 would be just. In general, however, we shall 

 observe that a great previous mortality produces 

 a more sensible effect on the births than on the 

 deaths. By referring to the table it will appear, 

 that the number of annual deaths regularly in- 

 creases with the increasing population, and nearly 

 keeps up the same relative proportion all the way 

 through. But the number of annual births is not 

 very different during the whole period, though in 

 this time the population had more than doubled 

 itself ; and therefore the proportion of births to the 

 whole population, at first and at last, must have 

 changed in an extraordinary degree. 



It will appear therefore how liable we should 



