TABLE I. When in any country there are 103,000 persons living, and the mortality is 1 in 36. The proportion of the TABLE II. The proportion of the excess of births above Periods of doubling excess of births above Periods of doubling in the deaths to the whole in years and ten the deaths, to the whole years and ten thouof the living. thousandth parts. of the living. sandth parts. CHAP. XII. Effects of Epidemics on Registers of Births, Deaths, and Marriages. IT appears clearly from the very valuable tables of mortality, which Sussmilch has collected, and which include periods of 50 or 60 years, that all the countries of Europe are subject to periodical sickly seasons, which check their increase; and very few are exempt from those great and wasting plagues which, once or twice perhaps in a century, sweep off the third or fourth part of their inhabitants. The way in which these periods of mortality affect all the general proportions of births, deaths, and marriages, is strikingly illustrated in the tables for Prussia and Lithuania, from the year 1692 to the year 1757a. a Sussmilch, Göttliche Ordnung, vol. i. table xxi. p. 88 of the tables. TABLE pass, The table, from which this is copied, contains the marriages, births and deaths for every particular year during the whole period; but to bring it into a smaller comI have retained only the general ave rage drawn from the shorter periods of five and four years, except where the numbers for the individual years presented any fact worthy of particular observation. The year 1711, immediately succeeding the great plague, is not included by Sussmilch in any general average; but he has given the particular numbers, and if they be accurate they shew the very sudden and prodigious effect of a great mortality on the number of marriages. Sussmilch calculates that above one third of the people was destroyed by the plague; and yet, notwithstanding this great diminution of the population, it will appear by a reference to the table, that the number of marriages in the year 1711 was very nearly double the average of the six years preceding the plague. To produce this effect, |