It is not the object of this work to present a detailed history of influenza. We refer the reader seeking for such information to the above mentioned historians. Only the most noteworthy outbreaks will be mentioned. They occurred during the following eras:

1510: Wide distribution over Europe. Direction in general from south to north. Malta, Sicily, Spain, Portugal, Italy, France, Germany, Holland, England, and Hungary.

1557: The statements vas to course and direction are contradictory: Asia, Constantinople, Sicily, then toward the north-Italy, Switzerland, France, Spain, Holland.

1580: First real pandemic: at first a general distribution over the Orient, then Constantinople and North Africa. In Europe the direction in general was from east to west and from south to north. From Constantinople to Venice, Sicily, Italy, France, Spain, Portugal, Hungary, Bohemia, Germany, Holland, Belgium, England, Denmark, Sweden, and Livonia.

Seventeenth century: Very scanty reports concerning influenza. In the year 1627 a great epidemic occurred in North America which was believed to have spread from there to South America (Chile) and thence to the West Indies.

1709-12: Probably a single period of epidemics of wide distribution- throughout Italy, France (1712), Germany, Belgium, Denmark, without particular direction.

1729-33: First invasion, beginning in 1729, with the direction from east to west: Russia, Sweden, Poland, Germany, Austria-Hungary, England, Switzerland, France, Italy, Iceland, and perhaps America also. Second invasion in 1732, presumably beginning in Russia; the direction of the epidemic definitely determined; Poland, Germany, Switzerland, France, England, Italy, Spain, and America (?). Minor outbreaks up to the years 1735-38.

1742-43: Beginning, it would appear, upon the coasts of the Baltic Sea, thence spreading to Germany, Switzerland, Italy, France, Netherlands, England. Minor outbreaks until 1745 (Germany).

1757-58, 1761-62, and 1767: Probably a single period of epidemics which arose first in North America, and thence seemed to have affected the old world; or they may have appeared simultaneously in both hemispheres. Confused geographic picture.

1781-82: Decided pandemic. First appearance in the fall of 1781 in China and India (?); then in December; in Siberia and Russia; in February, 1782; in Finland, then Germany, Denmark, Sweden, England, Scotland, Netherlands, France, Italy, and Spain.

1788-90: A most pronounced pandemic period. Began 1788 in Russia, then Germany, Austria-Hungary, Denmark, England, France, and Italy.

1799-1803: A long period, consisting of several invasions and outbreaks of the disease. The first pandemic invasion began December, 1799, in Russia; then Galicia, Poland, Germany, France, and Denmark. After an interval of five months (analogous to our most recent pandemic), next in October, 1800; furthermore, in the winter of 1802-03, individual local epidemics of considerable territorial extent in France, Germany, England, Switzerland. Minor outbreaks extended up to the years 1805 and 1808. In the years 1811, 1815-16, 1824-26, numerous influenza epidemics occurred in North and some also in South America.

1827: Extensive epidemic distribution throughout eastern Russia, especially in Siberia.

1830-33: This remarkably intense and extensive influenza period, distributed over the entire world, consists of two or three pandemic outbreaks. The first invasion (1830-31) seems to have had its origin in China, affecting in its course Manila, Polynesia, Borneo, Java, Sumatra, and India. The European invasion began, so far as we know, in Russia (October, 1830), extending thence in 1831 through Courland and Livonia, Poland, eastern Prussia, Silesia, and the remainder of Germany, Austria, Finland, Denmark, Belgium, France, Sweden, England, Scotland, Switzerland, Italy. It reached Spain in January of 1832, and at the same time North America. After a pause of one year Europe was infected anew by a second exceptionally intense outbreak, which traveled in the same direction, namely, from east to west. The course of the disease which originated in Russia (January, 1833) is almost identical with the epidemic of 1831-32 just described. Three years later a new pandemic invasion traveled right around the earth.

1836-37: After influenza had raged in Australia, South Africa, Java, and Farther India in the late fall of 1836, there followed the great European outbreak, taking the direction from east to west. It began in Russia in the year 1836, and extended thence in rapid strides to Sweden, Denmark, Germany, England, France, Holland, Belgium; Switzerland, upper Italy, Spain, and Portugal. We can plainly distinguish a primary northern outbreak extending from east to west, and a subsidiary outbreak from this point, with the direction from north to south. The smaller epidemic outbreaks during the succeeding year should probably be considered as sequels of the epidemic of 1836-37.

1847-48: A well defined direction cannot be determined in this pandemic.

After an epidemic had occurred in England, Denmark, Belgium, Switzerland, and France in the years 1846-47, there followed in March, 1847, an outbreak in Russia. But the principal outbreak occurred in September, 1847, first apparently in France, and from there in rapid succession in Germany, Denmark, England, Scotland, Switzerland, Italy, Spain, and Greece. In January, 1848, we find North America affected. Of non-European countries to be recorded are the West Indies, Newfoundland, New Zealand, the Sandwich Islands, Egypt, Algeria, Syria, and the west coast of Africa. The epidemics occurring in the years 1850-51, 1855, 1857-58, and 1874-75, which were counted by A. Hirsch as real pandemics, we consider should not be placed in this category.

1889-90: This, the most extensive and important of all the pandemic outbreaks, extending as it did over all the world, will be described in detail below.

Besides these chief outbreaks of the pestilence recorded in the preceding paragraphs, there were also numerous more or less extensive epidemics, involving a greater or less area. If we carefully analyze the influenza epochs compiled by historians, and especially the description by A. Hirsch, comprising the years from 1173 to 1875, we shall see that in the last century, which was characterized by increasing facilities for the distribution of news, scarcely a year passed in which the epidemic prevalence of influenza in some part of the world is not recorded. Many of these local and limited epidemics were nothing more than late sequels of the great pandemics, often separated by long intervals, the germs of the disease planted by these epidemics having remained alive for years. We must speak of influenza epochs and not of influenza years. Many of the other epidemies described as influenza have very probably nothing in common with "influenza vera." They are epidemics of local "catarrhal fever." Here we come upon an important point which we must treat more in detail.