A Venetian "plague miracle" in 1464 and 1576.

THE ACCEPTED theory of bubonic plague among medieval physicians is to be found in the tracts offering defences both prophylactic and therapeutic against plague composed in the years after the Black Death of 1348.1 There it was stated that the abscesses of plague (apostemata, now called buboes) were the sites of poisonous discharges emitted from the heart, liver and brain, after these had been affected by poisonous vapours in the atmosphere. The vapours, which were caused by the movements of the stars, entered the body through the pores of the skin, and the treatment recommended by physicians was in accordance with this theory. To evacuate the poison, the patient should be bled; to keep the pores closed to the air, he should avoid baths, coitus, and certain foods; to preserve the equilibrium of the humours against possible disruption from the miasmal vapours, he should lead a temperate life; and unguents were to be applied to the buboes. We now know that this treatment must have been completely ineffective, so that it is no wonder that non-physicians preferred simply to flee from infected areas, as, for example, the narrators of Boc-caccio's Decameron during the Black Death, or to try to insulate their houses from the poisonous air, or to pray, worship, and to go on pilgrimages to the shrines of saints who were said to have protected people from plague in the past. These remedies were certainly no less effective than those offered by the physicians, and they continued to be used long after the end of the Middle Ages. This state of affairs is vividly illustrated in the history of a manuscript which has recently come to light (see Figure 1). It is a leaf of dark brown parchment measuring 420 x 345 mm., with a horizontal crease across the middle. One side of the leaf contains thirty-five lines of prose in Venetian dialect of Italian, written in semi-humanistic script of the second half of the fifteenth century. The other side is blank, except for the figures 4 and V=896 written in an eighteenth-or nineteenth-century hand, adjacent to each other on the same side of the crease. The borders of the parchment are paler than the rest, and are perforated with rust-stained holes, from which one can deduce that the manuscript was formerly kept nailed in a frame. The text recounts an incident at the Benedictine convent of Santa Croce …