(From Epidemius 3529 upon, and the people). Epichorios;pandemius,popularis, regionalis morbus. An epithet of diseases which at certain times are popular, and frequently attack; then for a time disap-year, and again return.

The extensive influence of epidemic diseases has excited the greatest attention to their causes. In almost every ruder age they have been referred to the anger of their peculiar divinities, and sacrifices were instituted to reconcile them. More lately Dr. Webster has attempted to connect them with the eruptions of volcanos, or the devastation of earthquakes. A more sound philosophy, and more attentive observation have shown, that they are owing very often to the effluvia of neighbouring marshes, and their occasional appearance is connected with the prevailing wind which passes from the marsh to the habitations. Another cause of their prevalence is, the wind from the marsh coinciding with the time when the moist ground begins to appear, from the waters subsiding. This is the period of sickness; for the marsh, while covered with water, is innocuous Another cause of epidemics is the weather. Along continued warm season, suddenly interrupted by a cold piercing wind, will produce a violent and extensive epidemic, which particularly attacks in the highest, and apparently the most healthy, situations; for this reason, that the inhabitants are there most exposed to cold. But if this interchange of weather occurs to the inhabitants of a crowded city, the epidemic will be highly putrid, and often fatal. Should contagion of a malignant kind concur, the devastation of the epidemic will increase in proportion. These are the concurring causes of the American yellow fever, and the late fatal epidemics in Spain.

There are, however, causes which we cannot investigate. Extensive epidemics appear, and travel in succession, with different severity, through every part of the globe that we are acquainted with. The destroying angel seems to move with a studied regularity, without our being able to arrest his steps or alter his course. We often find these inexplicable epidemics without much danger, influencing the appearance of diseases and their treatment. Thus, while some epidemics prevail, evacuations from the bowels are necessary in almost every complaint; even where, in appearance, unnecessary or contraindicated. In others, they are, with difficulty, borne in any disorder. This necessary attention to the prevalence of the constitution merits very particular attention; and the more extensive a physician's experience is, by so much will he be better able to treat the commonest disease.

Epidemics connected with the seasons or prevailing temperature may be easily traced, and we shall find them occasionally mitigated or severe: sometimes apparently stopped; at others exerting their power with increased virulence. The peculiar treatment, however, suggested by a general epidemic, should not at once be discontinued. The human constitution does not soon change; the alteration is gradual, and almost imperceptible: nor should the medical plans be altered till they are decidedly injurious.

When an epidemic has continued for some time, the body is habituated to the influence of the morbid cause; suffers less from it; and the health is more readily restored. At this time, remedies before useless are found to produce some salutary effects; and, at the end of an epidemic, we usually are told of a plan which never fails. On its return, these boasted plans are as ineffectual as before. In fact, they only combated, with success, a disease of reduced power.

We greatly want a judicious and well connected aecount of epidemics. Dr. Webster has lately brought together a very extensive collection of facts of this kind, with the views formerly mentioned; but the chaff is so intimately mixed with the grain, that the salutary information is with difficulty selected. See also Observations on Epidemic Disorders, etc.

We cannot give a better view of the epidemics of the two last centuries than in the comprehensive abstract of Dr. Sims.

"1. The first epidemic constitution was as follows: The years 1590, 1591, 1592, were all exceedingly dry; as was part of 1593; afterwards very rainy weather until the end of 1597. In 1593 the plague killed eleven thousand five hundred and three in London; the same year it was prevalent in Alcmaar. A catarrh prevailed in 1597. The rainy weather began in Florence in 1592, during which a pestilential fever raged there, attended with a whitish tongue, and an inflammation, with ulcers about the throat and mouth.

"2. There was, in 1598, an excessive heat and drought, which continued next year; 1600, a severe winter; 1601, a drought of five months' continuance; 1602, a cold spring and summer, cold dry harvest and winter; the rest of this constitution very rainy, until the end of 1608, except seven weeks' frost in 1607. In 1603 the plague was imported from Ostend, where, and in the Low countries, it raged much, and killed thirty-six thousand two hundred and sixty-nine in London.

"3. In 1609, three months most rigorous frost, wherein the Thames became like a solid highway; 1610, an excessive hot dry summer, as were those of 1611 and 1612; 1616, 1617, and 1619. The winters of 1614 and 1615 great frost and snow; the rest of this constitution wet until the end of 1624. In 1609 the plague broke out in Alcmaar, as also in Denmark. In 1610 the Hungarian fever commenced in many places, and made great havoc for several years, so as often to be denominated a plague. About the same time the malignant sore throat is supposed to have commenced in Spain, where it killed incredible numbers. In 1611 the plague is said to have destroyed two hundred thousand at Constantinople. In 1614 the most fatal small pox spread all over Europe. In 1618 the sore throat broke out at Naples, where it continued its ravages for twenty years; it was preceded by a similar disorder among cattle. In 1618 the plague existed in Bergen. In 1619 it broke out in Denmark and in Grand Cairo.