This eyewitness account Is provided by the Florentine humanist, Giovanni Boccaccio (1313-1375), one of the best minds and keenest observers of his time. Except for a touch of civic pride, Boccaccio writes with remarkable objectivity.
In the year of our Lord 1348, there happened at Florence, the finest city in all Italy, a most terrible plague; which, whether owing to the influence of the planets, or that it was sent from God as a just punishment for our sins, had broken out some years before in the Levant, and after passing from place to place and making incredible havoc all the way, had now reached the west. There, spite of all the means that art and human foresight could suggest, such as keeping the city clear from filth, the exclusion of all suspected persons, and the publication of copious instructions for the preservation of health, and notwithstanding manifold humble supplications offered to God in processions and otherwise, it began to show itself in the spring of the aforesaid year, in a sad and wonderful manner. Unlike what had been seen in the east, where bleeding from the nose is the fatal prognostic, here there appeared certain tumors in the groin or under the arm-pits, some as big as a small apple, others as an egg; and afterwards purple spots in most parts of the body; in some cases large and but few in number, in others smaller and more numerous--both sorts the usual messengers of death. To the cure of this malady neither medical knowledge nor the power of drugs was of any effect; whether because the disease was in its own nature mortal, or that the physicians (the number of whom, taking quacks and women pretenders into the account, was grown very great) could form no just idea of the cause, nor consequently devise a true method of cure; whichever was the reason, few escaped; but nearly all died the third day from the first appearance of the symptoms, some sooner, some later, without any fever or other accessory symptoms. What gave the more virulence to this plague, was that, by being communicated from the sick to the hale, it spread daily, like fire when it comes in contact with large masses of combustibles. Nor was it caught only by conversing with or coming near the sick, but even by touching their clothes, or anything that they had before touched. It is wonderful, what I am going to mention; and had I not seen it with my own eyes, and were there not many witnesses to attest it besides myself, I should never venture to relate it, however worthy it were of belief. Such, I say, was the quality of the pestilential matter, as to pass not only from man to man, but, what is more strange, it has been often known, that anything belonging to the infected, if touched by any other creature, would certainly infect and even kill that creature in a short space of time. One instance of this kind I took particular notice of: the rags of a poor man just dead had been thrown into the street. Two hogs came up, and after rooting amongst the rags and shaking them about in their mouths, in less than an hour they both turned round and died on the spot.
These facts, and others of the like sort, occasioned various fears and devices amongst those who survived, all tending to the same uncharitable and cruel end; which was, to avoid the sick and every thing that had been near them, expecting by that means to save themselves. And some, holding it best to live temperately and to avoid excesses of all kinds, made parties and shut themselves up from the rest of the world; eating and drinking moderately of the best, and diverting themselves with music and such other entertainments as they might have within doors; never listening to anything from without to make them uneasy. Others maintained free living to be a better preservative, and would balk no passion or appetite they wished to gratify, drinking and revelling incessantly from tavern to tavern, or in private houses (which were frequently found deserted by the owners and therefore common to every one), yet strenuously avoiding, with all this brutal indulgence, to come near the infected.
And such, at that time, was the public distress that the laws, human and divine, were no more regarded; for the officers, to put them in force, being either dead, sick, or in want of persons to assist them, every one did just as he pleased. A third sort of people chose a method between these two: not confining themselves to rules of diet like the former, and yet avoiding the intemperance of the latter; but eating and drinking what their appetites required, they walked everywhere with perfumes and nosegays to smell to, as holding it best to corroborate the brain: for the whole atmosphere seemed to them tainted with the stench of dead bodies, arising partly from the distemper itself, and partly from the fermenting of the medicines within them. Others with less humanity, but perchance, as they supposed, with more security from danger, decided that the only remedy for the pestilence was to avoid it. Persuaded, therefore, of this and taking care for themselves only, men and women in great numbers left the city, their houses, relations, and effects, and fled into the country, as if the wrath of God had been constrained to visit those only within the walls of the city, or else concluding that none ought to stay in a place thus doomed to destruction.
From The First Century of Italian Humanism, ed. Ferdinand Schevill (New York, F.S Crofts & Co., 1928), pp. 32-34.