After an interval of twenty years it broke out a second time quite suddenly (1505); revisited nearly all the seats of its former ravages, and again disappeared at the end of six months.

On its third visitation (1517), after an interval of eleven years, it again finished its course within six months.

Its fourth visitation (1528) was repeated after a further interval of precisely eleven years. Such was its violence on this occasion, that the historians of that day designate this period by the significant name of the “Great Mortality.” It drove Henry VIII. from London, destroyed several of the most distinguished persons of the Court, impressed the nation, from the monarch to the peasant, with an awful feeling of the uncertainty of life, continued its destructive course for its accustomed period of six months, and then again disappeared.

From this to its fifth and last visitation, twenty-three years elapsed (from 1528 to 1551.) It then broke out with unmitigated fury, spread once more over the whole of England, ceased within six months, and from that period has never reappeared in any country.

The Oriental Plague of the middle ages returned with a like periodicity; and so it does at the present day in the countries in which it maintains its ancient reign. It recurs with much regularity about every ten years.

The Fever Epidemics of the metropolis return pretty constantly about every ten or twelve years.

The Irish Typhus Epidemics have recurred nearly decennially for the last 150 years.

Epidemic Cholera, on its first visitation, ravaged Great Britain for a period of fifteen months. It then wholly ceased; after an interval of sixteen years it again broke out, and pursued its former course for the same exact period of fifteen months, and then ceased.

Within the brief interval of only five years, it last year (1854) accomplished its third visitation. It now protracted its stay for a period of seventeen months; coming sooner and staying longer.

9. Again, Epidemics resemble each other in the brevity of the space that intervenes between the attack and death.