There have been fourteen very widespread epidemics since 1510, all of which might appropriately be designated as pandemics. They are those of 1510, 1557, 1580, 1593, 1729, 1732, 1762, 1782, 1788, 1830, 1833, 1836, 1847, 1889 and 1918. Some of these have spread farther than others according to the records, but in nearly all we have reports of influenza being present in practically every country provided with a historian. We may find from the table another group in which there have been more or less extensive epidemics, apparently related, but without any general direction of spread. Such are the epidemics of 1709–12, 1757–67, 1802–03, 1838–47 and the period 1850–59. Finally, there are at least ten periods during which relatively small areas have been affected with epidemic influenza. Such for instance is the year 1688 when the disease was apparently localized in Great Britain and Ireland; in the year 1693 when England and the adjacent continent were involved, with little spread elsewhere; and again in 1742, when there was a slow spread through Germany into adjacent countries with recurrences in the former up until 1745. In England the following epidemics have been recorded, some of them in great detail: 1510 and 1557, described by Thomas Short; 1658 by Willis; 1675, by Sydenham; 1729–1743 by Huxham; 1732–33 by Arbuthnot; 1758 by Whytt; 1762 by Baker and Rutty; 1767 by Heberden; 1775 by Fothergill, who collected observations from many physicians; in 1782 by Gray, Haygath and Carmichael Smith; 1803 by Pearson and Falconer, and a great number of others; 1833 by Hingeston and others; 1837 by Streeten, Graves, and Bryson, etc.; 1847 by Peacock, Laycock and many others; also those of 1855 and 1889–93. According to Stallybrass, epidemic crests have been reached in England in 1789–90, 1802–03, 1830–32, 1840–41, 1848–51, 1854, 1869–70, 1879, 1890–91, 1898 and 1918 to 1920. The periodicity in multiples of ten years in this latter group is remarkable. The disease appears to have visited North America in the years 1627, 1647, 1729, 1732, 1737, 1762, 1782, 1789, 1811, 1832, 1850, 1857, 1860, 1874, 1879, 1889, 1900, 1915–1916 and 1918–20. Abbott speaks particularly of the years 1647, 1655 and 1697–98, 1732, 1762 and 1782 and 1889 as being years of especial epidemic prevalence in this country. CLINICAL AND EPIDEMIOLOGIC IDENTIFICATION.