26 Mr. T. li. Edmonds on Vital Force according 



scries of theoretical Life Tables — one representing <f Village Mor- 

 tality/' another " Mean Mortality/' and the third " City Mor- 

 taly," the principal series being that of Mean Mortality. At 

 any given age the rates of mortality in the three Tables are to 

 one another in the proportion of the numbers 5, 6, and 1\ respec- 

 tively. The same three numbers were intended to represent for 

 the fixed age of ten years the annual mortality per thousand 

 living according to the same three several Tables. The above 

 three Tables were deduced from the same formula, 



com.logP,= -^(l-/), 



with the three different values of a above mentioned. These 

 Tables were the first ever published in which the rate of morta- 

 lity -at any age was connected by a continuous and definite law 

 of increase or decrease with the rate of mortality exhibited for 

 every other age. The first of these theoretical Tables, desig- 

 nated as " Village Mortality/' is almost in exact coincidence at 

 every age with Heysham and Milne's Table for Carlisle (pub- 

 lished in 1815), as may be seen on inspection of Tables I. and 

 VI. hereunto annexed. 



In the ' Lancet 3 of the 9th and 16th of March, 1850, there ap- 

 peared a paper in which! compared the results of the u Village/' 

 " Mean/' and " City " Tables of mortality with the observed 

 rates of mortality, according to age, of various parts of the po- 

 pulation of England during the seven years 1838-1844, these 

 observed rates having been published by authority of the 

 Registrar- General in the year 1849. Extracts from these com- 

 pared results will be found in Table III. hereunto annexed. 

 On inspection of this Table it will be seen that the mortality, 

 according to age, of the total male population of the four heal- 

 thiest of the eleven Registrar's districts into which England has 

 been divided is sufficiently well represented by the theoretical 

 Table of " Village Mortality." Also it will be seen that the 

 theoretical Table of " City Mortality " is a good representation 

 of the mortality, according to age, of the male population of the 

 chief towns of England. Taking four classes of such towns, ar- 

 ranged according to intensity of mortality, it will be seen that 

 the mortality according to the " City " Table, at the various in- 

 tervals of age, agrees nearly with the mean mortality observed 

 in these four classes of chief towns. 



It is worthy of remark that, although the " City " Table is a 

 good representation of the mortality of the population of English 

 cities at ages under 10 years and at ages above 30 years, it is 

 not so for the intermediate period of age. One of the remark- 

 able results of the English observation is, that the mortality 

 of the populations of great towns between the ages of 10 and 30 



