The diffusive power of the virus of the Black Death, which has been equalled only by that of the plague in Justinian’s reign, may seem to have depended upon the favouring conditions that it met with. But although favouring conditions count for much, they are not all. The Black Death raged as furiously as anywhere among the nomade Tartars who were its first victims; the virus, as soon as it was let loose, put forth a degree of virulence which must have been native to it, or brought with it from its place of engendering. None the less the incidence of the Black Death in Europe had depended in part upon the preparedness of the soil. It came to Europe in the age of feudalism and of walled towns, with a cramped and unwholesome manner of life, and inhabited spots of ground choked with the waste matters of generations. But even amidst these generally fostering conditions, there would have been more special things that determined its election. It is a principle exemplified in all importations of disease from remote sources, in smallpox among the aerial contagions and in Asiatic cholera among the soil-poisons, that the conditions which favour diffusion abroad are approximately the same amidst which the infection had been originally engendered. A soil-poison of foreign origin makes straight for the most likely spots in the line of its travels; it may not, and often does not confine itself to these, but it gives them a preference. Thus, if we conclude on the evidence that the bubo-plague is a soil-poison having a special affinity to the products of cadaveric decomposition, we shall understand why the Black Death, when it came to England, found so congenial a soil in the monasteries, and in the homes of the clergy. Within the monastery walls, under the floor of the chapel or cloisters, were buried not only generations of monks, but often the bodies of princes, of notables of the surrounding country, and of great ecclesiastics. In every parish the house of the priest would have stood close to the church and the churchyard. One has to figure the virus of the Black Death not so much as carried by individuals from place to place in their persons, or in their clothes and effects, but rather as a leaven which had passed into the ground, spreading hither and thither therein as if by polarizing the adjacent particles of the soil, and that not instantaneously like a physical force, but so gradually as to occupy a whole twelvemonth between Dorset and Yorkshire. Sooner or later it reached to every corner of the land, manifesting its presence wherever there were people resident. Such universality in the soil of England, we have reason to think, it had. But it appears to have put forth its greatest power in the walled town, in the monastery, and in the neighbourhood of the village churchyard. CHAPTER IV. ENGLAND AFTER THE BLACK DEATH, WITH THE EPIDEMICS TO THE TUDOR PERIOD.