The order in this Table was also the order in time: the fever of 1661, which Willis calls malignant, remained as the constitution of the years following until the end of 1664; then began the pestilential, which passed definitely in the spring of 1665 into the plague proper. Willis, Sydenham and Morton, differing as they did on many points of theory and treatment, all alike taught the scale of malignity in fevers and plague, and all used the language of “constitutions.” The Great Plague of 1665 was, in their view, the climax of a succession of febrile constitutions of the air, being attended by much pestilential fever and followed by a fever which Morton places in the milder class of συνεχής. The epidemic Constitutions following the Great Plague. During the ten or twelve years following the Great Plague of London, the epidemic maladies which Sydenham dwelt most upon as the reigning types will appear on close scrutiny to have been on the whole proper to the earlier years of life. This cannot be shown in the simple way of figures; for the ages at death from the several maladies, although they were in the books of the Parish Clerks, were not published. There was some continued fever every year, which we may take to have been chiefly the endemic typhus of a great city, and there were also deaths among adults due to those reigning epidemics which fell most on the young. In 1667 and 1668 the leading epidemic was smallpox, with a continued fever towards the end of the period which Sydenham called “variolous,” for no other reason, apparently, than that it was part of a variolous constitution. In the autumn of 1669, and in the three years following, the epidemic mortality was peculiarly infantile, in the form of diarrhoea or “griping in the guts,” with some dysentery of adults, and some measles in 1670. From 1673 to 1676, the constitution was a comatose fever, which chiefly affected children, with a sharp epidemic of measles in the first half of 1674, attended by a very high mortality from all causes, and a severe smallpox in the second half of 1674, attended by a much lower mortality from all causes. There was also an influenza for a few weeks in 1675. In 1678 the “intermittent” constitution returned, having been absent for thirteen years, and continued through 1779-80, until its “strength was broken.” In 1681 smallpox was unusually mortal, the deaths being more than in any previous year. Most of these constitutions fall to be dealt with fully in other chapters: but as we are here specially concerned with the succession to the plague, it is to be noted how largely the epidemic mortality in London fell upon the age of childhood for a number of years after the Great Plague of 1665. It was observed both by English and foreign writers that the next epidemic following the Black Death of 1348-49, namely, that of 1361 in England and of 1359-60 in some other parts of Europe, fell mostly upon children and upon the upper classes of adults.