The Parish Clerks’ Bills of Mortality show clearly that from 1593 to the year 1800, _i.e._, for 207 years, the deaths invariably exceeded the births, and often to an enormous extent, the maximum being reached in the memorable year 1665, when the deaths were 87,339, as against 9,967 births. Taking the whole of the 18th century, it would appear from a table given by Henderson, in the “Encyclopædia Britannica,” that of the births and deaths registered, the excess of the latter averaged about 6,000 a year, or 600,000 for the century. At one time leprosy was common in London, and we know that in the reign of Edward III. the “black death,” which was probably plague, committed frightful ravages, and is said to have killed 100,000 in London; and this scourge reappeared at intervals up to the year 1665, the mortality then being enormously in excess of the very high mortality which was habitual. Between 1485 and 1551 there were epidemics of the sweating sickness, a disease different from plague but scarcely less deadly. We all know what epidemics of plague and sweating sickness did for London, but it may be thought that epidemics are accidental visitations, and are no criterion of the general health of the city. The numbers I have quoted from Henderson will make it impossible for us to believe that old London was at any time healthy, not even after the fire and the rebuilding. What were the chief ordinary diseases of London? This question may be answered by reference to the bills of mortality. I will take the year 1661, when 19,771 deaths were registered by the parish clerks, and will note those diseases which are credited with more than 100 deaths. These were: Abortive and still-born, 511; chrisomes and infants, 1,400; ague, 3,490; dysentery (bloody flux, scouring and flux), 314; childbed, 224; aged, 1,302; apoplexy and suddenly, 108; colic, 186; consumption, 3,788; convulsions, 1,198; dropsy and tympany, 967; flox and small-pox, 1,246; griping in the guts, 1,061; jaundice, 141; imposthume, 160; measles, 188; rickets, 413; rising of the lights, 227; spotted fever and purples, 335; stopping of the stomach, 170; surfeit, 212; teeth and worms, 1,195. Looking at the table, and using the best of my judgment in interpreting it, I should say that about one-fourth of the deaths were due to the accidents of parturition and the diseases of infants, and another fourth due to fevers. It is to be noted also that plague is answerable for 20 deaths, although this was not a plague year. What were the causes of the high mortality in Old London?