1?S ESSAY ON PROBABILITIES. 



proceed to point out the connexion between a table of 

 mortality and one of population. 



The whole number of persons inhabiting any country 

 is in continual state of increase from births and immi- 

 gration, and of decrease from deaths and emigration. 

 There are few countries in which immigration and 

 emigration produce any serious effect upon the popu- 

 lation, and, in times of very moderate quiet and pros- 

 perity, the births always exceed the deaths : so that, 

 generally speaking, the number of people alive in a 

 given country is yearly augmented by the excess of the 

 births over the deaths. If accurate registers of births 

 and deaths (with the ages at death) were kept for a 

 a century and a half, accompanied, if need were, by a 

 register of incomers and outgoers, with their ages, the 

 community would be in possession of a complete history 

 of its statistical changes, from which the law of mor- 

 tality might be deduced, and its fluctuations noted, if 

 any. 



Again, if in any one year a complete census were made, 

 registering the age of every individual, and if the deaths 

 which took place in the 365 days next following the 

 day of the census were noted, the law of mortality 

 could be deduced. In such a case, the numbers of the 

 living at every age would be so large that the propor- 

 tion of deaths among them in a single year could be 

 safely depended on for pointing out, with great nearness, 

 the law which regulates the mortality of large masses of 

 people. 



No such statistical means exist in this country, 

 partly from the defective manner in which the censuses 

 of population are made, partly from the circumstance of 

 the registries of births and deaths having been, almost 

 up to the time of writing this work, connected with 

 the religious ceremonies of the established church, which 

 has had the effect of excluding many dissenters from 

 registration. In the absence of all specific information, 

 recourse was had to the registers of burials, which are 

 usually accompanied by a statement of the age of the 



