The history of epidemic influenza extends back with definite authenticity to the Middle Ages, with a fair amount of assurance to the beginning of the Christian Era and with presumptive reliability even before that period. Beyond this statement, nothing definite can be said until the first epidemic reported by Short and found in the English Annals in the year 1510. This, the first reliable record, presented some features not unlike those occurring in the present epidemic. Two or three striking things stand out in this record—namely, the presence of nose bleed, pneumonia and the very great danger to gravid women. Here, for the first time, the meteorological conditions were elaborately studied and persistently dwelt upon. One other impressive thing, also reported by Short, was that in 1580 the disease showed a tendency to return after a period of quiescence. Attention is called to this because the epidemic, while it was exceedingly prevalent in the months of August and September, became pandemic in October and November. Another feature was that during the years intervening between 1580 and 1658 sporadic cases of this disease were frequently reported. During the latter year another epidemic appeared in the month of April. In 1657 and 1658 at London the summer was very warm, the winter came on early, there was much snow and the spring was very moist. The prevailing opinion at this time, and the first stated by Willis, was that the widespread disease was due to the weather influences on the circulation, poisoning the blood of the patients, and “not blasts of malignant air.” The disease prevailed in the large cities, recurring again in the autumn in an extensive form through the villages and country. Sydenham, in his communication on the epidemic in 1675, wrote emphatically on the influence of the infection on pregnant women, and here used the term “tussis epidemicus” as a name for the disease. The summer of 1675 was wet with an inconstant autumn. La Grippe prevailed in France and Germany, according to Atmuller. In England in 1676, the autumn was pleasant, but suddenly became cold and moist. La Grippe then started in Germany during September after a summer and a beginning autumn which was very rainy. Molyneux in his description of the epidemic of 1693 in Dublin called attention to a feature, very striking to the recent pandemic, that the aged to a great extent escaped the infection. This would seem a somewhat unique feature until that epidemic is compared with the present one. In 1729 Morgagni and others stated that over all Europe the winter of 1728 was very rigorous, the spring was cold and the summer and autumn very variable, while January and February of that year were very moist. Huxham in his record of 1729, the fifth extensive one on record in the English Annals, which extended into 1733, stated from his study at Plymouth that the epidemic was exceedingly mild in the year 1733, and, with the exception of infants and consumptive old