422 Of the Checks to Population Bk. ii. 



varying circumstances of every country, they are 

 both precarious guides. From the greater appa- 

 rent regularity of the births, political calculators 

 have generally adopted them as the ground of 

 their estimates in preference to the deaths. 

 Necker, in estimating the population of France, 

 observes, that an epidemic disease, or an emigra- 

 tion, may occasion temporary differences in the 

 deaths, and that therefore the number of births 

 is the most certain criterion.* But the very cir- 

 cumstance of the apparent regularity of the births 

 in the registers will now and then lead into great 

 errors. If in any country we can obtain registers 

 of burials for two or three years together, a plague 

 or mortal epidemic will always shew itself, from 

 the very sudden increase of the deaths during its 

 operation, and the still greater diminution of them 

 afterwards. From these appearances, we should 

 of course be directed, not to include the whole of 

 a great mortality in any very short term of years. 

 But there would be nothing of this kind to guide 

 us in the registers of births ; and after a country 

 had lost an eighth part of its population by a 

 plague, an average of the five or six subsequent 

 years might shew an increase in the number of 

 births, and our calculations would give the popu- 

 lation the highest at the very time that it was the 

 lowest. This appears very strikingly in many of 

 Sussmilch's tables, and most particularly in a 

 table for Prussia and Lithuania, which I shall in- 



* De 1' Administration des Finances, torn. i. c. ix. p. 252. 12aio. 

 1 785. 



