University of Paris

University of Paris Medical Faculty, Writings on the Plague

Attempts were made to explain the plague including attributing it to divine wrath or even to a plot by Jews. Church scholars in the fourteenth century sought rational explanations based on the understanding that disease was caused by bad air which in turn may have been brought about by a planetary conjunction or by earthquakes and volcanoes. However rational, all explanations and cures were complete failures (though the idea of quarantine did somewhat succeed). Source: R. Hoeniger, ed., Der Schwarze Tod (Berlin: 1882), appendix iii, pp. 152-6.

CHAPTER 1 OF THE FIRST PART: CONCERNING THE UNIVERSAL AND DISTANT CAUSE

We say that the distant and first cause of this pestilence was and is the configuration of the heavens. In 1345, at one hour after noon on 20 March, there was a major conjunction of three planets in Aquarius. This conjunction, along with other earlier conjunctions and eclipses, by causing a deadly corruption of the air around us, signifies mortality and famine - and also other things about which we will not speak here because they are not relevant. Aristotle testifies that this is the case in his book Concerning the Causes of the Properties of the Elements, in which he says that mortality of races and the depopulation of kingdoms occur at the conjunction of Saturn and Jupiter, for great events then arise, their nature depending on the trigon in which the conjunction occurs. And this is found in ancient philosophers, and Albertus Magnus in his book, Concerning the Causes of the Properties of the Elements (treatise 2, chapter 1) says that the conjunction of Mars and Jupiter causes a great pestilence in the air, especially when they come together in a hot, wet sign, as was the case in 1345. For Jupiter, being wet and hot, draws up evil vapours from the earth and Mars, because it is immoderately hot and dry, then ignites the vapours, and as a result there were lightning, sparks, noxious vapours and fires throughout the air.

These effects were intensified because Mars - a malevolent planet, breeding anger and wars - was in the sign of Leo from 6 October, 1347 until the end of May this year, along with the head of the dragon, and because all these things are hot they attracted many vapours; which is why the winter was not as cold as it should have been. And Mars was also retrograde and therefore attracted many vapours from the earth and the sea which, when mixed with the air, corrupted its substance. Mars was also looking upon Jupiter with a hostile aspect, that is to say quartile, and that caused an evil disposition or quality in the air, harmful and hateful to our nature. This state of affairs generated strong winds (for according to Albertus in the first book of his Meteora, Jupiter has the property of raising powerful winds, particularly from the south), which gave rise to excess heat and moisture on the earth; although in fact it was the dampness which was most marked in our part of the world. And this is enough about the distant or universal cause for the moment.

CHAPTER 2 OF THE FIRST PART: CONCERNING THE PARTICULAR AND NEAR CAUSE

Although major pestilential illnesses can be caused by the corruption of water or food, as happens at times of famine and infertility, yet we still regard illnesses proceeding from the corruption of the air as much more dangerous. This is because bad air is more noxious than food or drink in that it can penetrate quickly to the heart and lungs to do its damage. We believe that the present epidemic or plague has arisen from corrupt air in its substance, and has not changed in its attributes. By which we wish it be understood that air, being pure and clear by nature, can only become putrid or corrupt by being mixed with something else, that is to say, with evil vapours. What happened was that the many vapours which had been corrupted at the time of the conjunction were drawn up from the earth and water, and were then mixed with the air and spread abroad by frequent gusts of wind in the wild southerly, gales, and because of these alien vapours which they carried the winds corrupted the air in its substance, and are still doing so. And this corrupted air, when breathed in, necessarily penetrates to the heart and corrupts the substance of the spirit there and rots the surrounding moisture, and the heat thus caused destroys the life force, and this is the immediate cause of the present epidemic.

And moreover these winds, which have become so common here, have carried among us (and may perhaps continue to do so in future) bad, rotten and poisonous vapours from elsewhere: from swamps, lakes and chasms, for instance, and also (which is even more dangerous) from unburied or unburnt corpses - which might well have been a cause of the epidemic. Another possible cause of corruption, which needs to be borne in mind, is the escape of the rottenness trapped in the centre of the earth as a result of earthquakes - something which has indeed recently occurred. But the conjunctions could have been the universal and distant cause of all these harmful things, by which air and water have been corrupted.

CHAPTER 3: CONCERNING PROGNOSTICATION AND SIGNS

Unseasonable weather is a particular cause of illness. For the ancients, notably Hippocrates, are agreed that if the four seasons run awry, and do not keep their proper course, then plagues and mortal passions are engendered that year. Experience tells us that for some time the seasons have not succeeded each other in the proper way. Last winter was not as cold as it should have been, with a great deal of rain; the spring windy and latterly wet. Summer was late, not as hot as it should have been, and extremely wet - the weather very changeable from day to day, and hour to hour; the air often troubled, and then still again, looking as if it was going to rain but then not doing so. Autumn too was very rainy and misty. It is because the whole year here - or most of it - was warm and wet that the air is pestilential. For it is a sign of pestilence for the air to be wain and wet at unseasonable times.

Wherefore we may fear a future pestilence here, which is particularly from the root beneath, because it is subject to the evil impress of the heavens, especially since that conjunction was in a western sign. Therefore if next winter is very rainy and less cold than it ought to be, we should expect an epidemic round about late winter and spring - and if it occurs it will be long and dangerous, for usually unseasonable weather is of only brief duration, but when it lasts over many seasons, as has obviously been the case here, it stands to reason that its effects will be longer-lasting and more dangerous, unless ensuing seasons change their nature in the opposite way. Thus if the winter in the north turns out to be cold and dry, the plagues might be arrested.

We have not said that the future pestilence will be exceptionally dangerous, for we do not wish to give the impression that it will be as dangerous here as in southern or eastern regions. For the conjunctions and the other causes discussed above had a more immediate impact on those regions than on ours. However, in the judgement of astrologers (who follow Ptolemy on this), plagues are likely, although not inevitable, because so many exhalations and inflammations have been observed, such as a comet and shooting stars. Also the sky has looked yellow and the air reddish because of the burnt vapours. There has also been much lightning and flashes and frequent thunder, and winds of such violence and strength that they have carried dust storms from the south. These things, and in particular the powerful earthquakes, have done universal harm and left a trail of corruption. There have been masses of dead fish, animals and other things along the sea shore, and in many places trees covered in dust, and some people claim to have seen a multitude of frogs and reptiles generated from the corrupt matter; and all these things seem to have come from the great corruption of the air and earth. All these things have been noted before as signs of plague by numerous wise men who are still remembered with respect and who experienced them themselves.

No wonder, therefore, that we fear that we are in for an epidemic. But it should be noted that in saying this we do not intend to exclude the possibility of illnesses arising from the character of the present year - for as the aphorism of Hippocrates has it: a year of many fogs and damps is a year of many illnesses. On the other hand, the susceptibility of the body of the patient is the most immediate cause in the breeding of illnesses, and therefore no cause is likely to have an effect unless the patient is susceptible to its effects. We must therefore emphasize that although, because everyone has to breathe, everyone will be at risk from the corrupted air, not everyone will be made ill by it but only those, who will no doubt be numerous, who have a susceptibility to it; and very few indeed of those who do succumb will escape.

The bodies most likely to take the stamp of this pestilence are those which are hot and moist, for they are the most susceptible to putrefaction. The following are also more at risk: bodies bunged up with evil humours, because the unconsumed waste matter is not being expelled as it should; those following a bad life style, with too much exercise, sex and bathing; the thin and weak, and persistent worriers; babies, women and young people; and corpulent people with a ruddy complexion. However those with dry bodies, purged of waste matter, who adopt a sensible and suitable regimen, will succumb to the pestilence more slowly.

We must not overlook the fact that any pestilence proceeds from the divine will, and our advice can therefore only be to return humbly to God. But this does not mean forsaking doctors. For the Most High created earthly medicine, and although God alone cures the sick, he does so through the medicine which in his generosity he provided. Blessed be the glorious and high God, who does not refuse his help, but has clearly set out a way of being cured for those who fear him. And this is enough of the third chapter, and of the whole first part.

68. THE ASTROLOGICAL CAUSES OF THE PLAGUE, GEOFFREY DE MEAUX

Geoffrey de Meaux was an astrologer who had been associated with the French Court earlier in the fourteenth century. The astrological measurements given in this treatise, however, relate to Oxford, which suggests that it was composed (or at least rewritten) there. Unlike the three astrologers mentioned in 57, de Meaux wrote this commentary on the 1345 conjunction after the outbreak of plague, and accordingly stresses the malign role of Saturn and Mars rather than the possible contribution of Jupiter.

Bodleian Library, Oxford, MS Digby 176 fos. 26-29.

I have been asked by some of my friends to write something about the cause of this general pestilence, showing its natural cause, and why it affected so many countries, and why it affected some countries more than others, and why within those countries it affected some cities and towns more than others, and why in one town it affected one street, and even one house, more than another, and why it affected nobles and gentry less than other people, and how long it will last. And they asked that after explaining the cause I should discuss appropriate remedies, drawing on my own opinions and medical advice. In order to demonstrate the cause of all these things I shall begin with the basics, as set forth by the wise authors, philosophers and astrologers who have had things to say on such matters.

Ptolemy in chapter 4 of the third book of his Quadripartitum cites Plato and Aristotle in support of the contention that God first created the heavens and the stars, and endowed them with the power to rule all earthly matters, and because of this it can be said that everything which befalls us happens at the will of God; for it is God himself who moves the heavens and whatever is within them, and it is through this motion that there come all the chances of generation and corruption, and all the other chances which lie outside our free will. Haly also cites Ptolemy as saying in the prologue to the first book of the Quadripartitum that the heavenly bodies confer on the inferior bodies below them similar powers, if they are naturally disposed to receive them. He also says in the Quadripartitum that heavenly bodies can bring about changes and events when they are turned towards us, and that this is a natural power, like the power of adamant to attract iron or scammony to purge yellow bile. Friar Roger Bacon in his treatise on the significance of places says that every point on the earth is at the apex of a pyramid formed by the converging lines of various heavenly powers; and this explains why you get plants of various species within one tiny piece of ground, or find twins who differ in character and behaviour, and in their aptitude for scholarship, languages or business.

Ptolemy divided the twelve signs of the Zodiac, through which all the planets move, into four groups of three, which he called trigons or triplicities, each of which is identified with one element. Thus the trigon of Aries, Leo and Sagittarius is identified with fire, which is hot and dry; the trigon of Taurus, Virgo and Capricorn with earth, which is cold and dry; the trigon of Gemini, Libra and Aquarius with air, which is hot and wet; and the trigon of Cancer, Scorpio and Pisces with water, which is cold and wet. Ptolemy also divided the whole inhabited world into four principal parts, each of which he identifies with one of the trigons. Ptolemy also says that the conjunctions of the two highest planets, that is Saturn and Jupiter, are of three types: major, minor and mean. A major conjunction is one in which these two planets begin their conjunction in the trigon of fire and remain in conjunction in the other trigons in turn until they return to the trigon of fire, but another sign from that in which they started, and this happens every 960 years. A mean conjunction is when these two highest planets begin their conjunction in one of the four triplicities and it lasts until they enter another, and this happens every 240 years. A minor conjunction is when they come together in any one trigon and this happens about every 20 years.

Now that the basics have been discussed, you can consider the reasons for such a great mortality in so many countries, and how the illness came through the influence of the stars. Ptolemy in chapter 4 of the second part of the Quadripartitum says: the important things are the strengths and powers of the hour, the conjunctions and oppositions, eclipses of the sun and moon, and the places the planets cross at that hour. Wherefore it has been, and is, known by all astrologers that in the year 1345 (taking the year to begin in January) there was a total eclipse of the moon, of long duration, on 18 March. At the longitude of Oxford it began an hour after the moon rose, and at the time the two planets were in conjunction in Aquarius, and Mars was with them in the same sign, within the light of Jupiter.

The sun is the lord, the director of all events, both general and specific, and the moon is second to him in dominion and power, and their effect is to intensify the effects of the planets acting with them. It is therefore in the natural course of events, and not to be wondered at, that such a great configuration should bring about major events on the earth, from the nature of the planets which drew to themselves the natures of the sun and moon. For when the sun is directly opposite the moon, as occurs in a total eclipse, then the power of each of them reaches the earth in a straight line, and the mingling of the influence of sun and moon with that of the superior planets creates a single celestial force which operates in conformity with the nature of the superior planets, which have drawn to themselves the powers of the sun and moon. The same thing happens in compound medicines: turbith naturally expels phlegm from the stomach and veins, and if it is mixed with ginger the mixture expels phlegm, and since ginger is not in itself an expellant it has taken on the nature of turbith. It is the same with the planets. On their own they cannot achieve anything great or universal, but when compounded with the sun and moon (at a time when these are aligned with each other and with the earth) they bend the nature of the two luminaries to their own nature, and thus with the power of the two luminaries are able to achieve great things which have a general and universal impact.

These natural causes affect the whole inhabited world between east and north. According to Ptolemy, Saturn, which was one of the partners in the conjunction, governs the whole eastern part of the inhabited world; Mars the whole western part; and Jupiter, besieged by both of them in the conjunction, rules the whole northern part. Thus the greater part of the earth was influenced, because of the place of the conjunction and because the planets involved rule parts of the world, as I have just described, and also because all the parts of the world where the eclipse was visible above the horizon shared in the effect of the configuration. Therefore this is why it affected so many provinces. And the reason why some were affected more than others is that a planet has no effect in a place over which it exerts no influence, as Ptolemy testifies in his Centilogium, and the superior planets in this conjunction had an influence over the places they rule and not elsewhere. And the reason why some towns and cities were affected more than others in the same provinces is as follows. Each city, town and home has fixed stars and planets ruling it, as Ptolemy testifies in the Centilogium. Therefore wherever the rulers of these places agree in power and effect with the planets and stars bringing the general mortality, those subject to them will have been made ready to receive that celestial influence upon their bodies.

It now remains to assign a reason why in one town it affected one street more than another, and also one house more than another. The answer is the same in both cases. Not all streets were affected in the same way, or both sides of one street, or neighbouring houses, because they do not have the same influences or rulers, and therefore the impact of the heavens cannot affect them all equally-for that action of which I speak is natural and operates according to the rules of nature. It cannot act in the same way in every case, but only has an effect insofar as the ground has been prepared for it.

It now remains to say why nobles and gentry were less affected than the rest of the population. It was and is known to all astrologers that at the time of this eclipse the three superior planets were in the sign of Aquarius, where the fixed stars are not of the first magnitude and, save for one which is in the south, far distant from us, are lesser stars which signify the common people, and therefore the effect of the illness which they brought touched those people moreÉ

It now remains to say how long the effects of that configuration on 18 March, 1345 will last. It is known to all astrologers that the duration of obscurity of the lunar eclipse when there was the conjunction of the three superior planets was three hours, 29 minutes and 54 seconds. That three hours and a half (roughly) when multiplied by 20, which is the number of years between these minor conjunctions of Saturn and Jupiter, make 70, which, divided by the 13 lunar months which make up the solar year, give 5 years and 5 lunar months, denoting the duration of the universal effect of that configuration of the two superior planets together with the lunar eclipse, as Ptolemy witnesses in the second book of the Quadripartitum where he says: the impact of a solar eclipse will last for as many years as there were hours of darkness, and in the case of a lunar eclipse for as many months as there were hours of darkness. And the commentator adds at that point that this calculation relates just to the eclipse; when it occurs with something else, such as a conjunction of Saturn and Jupiter, the duration of its effect will be proportionately lengthened.

You should understand, however, that I do not wish to imply that the mortality comes only from Saturn and Jupiter but rather through Mars, which was mixed with them at the time of the eclipse. And the condition which resulted from all of these will last according to the nature of the dominant planets in that configurationÉ

Now it remains to write about the best remedy to be taken against this celestial influence, and you should know, as Ptolemy says in the third chapter of the first book of the Quadripartitum, that not all the things which befall men through the heavenly bodies are inevitable - that is, cannot be avoided. Some of the works of the stars are inevitable in this sense, and cannot in the nature of things be avoided, but others are things which it is possible to avoid, so that one part of the events befalling men arose through the general and universal pestilence, and did not befall them because of their individual nature. For in that mortality the greater and stronger force throws down the weaker and lesser. And you ought to know that should someone's nativity be the opposite of the configuration bringing the mortality, the mortality would not touch him; but should his nativity be broadly similar to the configuration, it would be clear that he lacks the contrary forces by which he could resist it. For as doctors and students of natural science know, transmutation is easy between bodies which have matching qualities. And where a person's nativity does not fully correspond to the configuration and yet is not totally contrary to it either, the body can, (given a good regimen and certain medicines which I will describe later), be preserved from this pestilence, but if he adopts a bad regimen then he can easily contract it.

Now the nature of the sun and moon is drawn, as I said earlier, to the nature of the dominant planets in the configuration, and those were Saturn and Mars; not Jupiter, although at the time of the eclipse he was exalted above Mars both in the eccentric and epicycle. For Jupiter is of a temperate power, and the more easily overcome as a result; just as temperate medicines are easily overwhelmed when mixed with intemperate medicines, and become intemperate themselves. Thus at the time of the eclipse, Jupiter was besieged by both the infortunes and, mixed with them, took the nature of both of them, but rather more of Saturn than of Mars; because Saturn was stronger than Mars in that place, because he had more dignities in that place, and because he was exalted above them in both the eccentric and epicycle. Saturn thus obtained dominion, and Mars was his second, as Ptolemy testifies.

Because Saturn was dominant, he brings cold, (greater than the sun could counter), to each country under his rule, and because of the sign in which the conjunction occurred men will experience the onset of lingering illnesses such as tuberculosis, catarrh, paralysis and gout; passions of the heart arising from unhappiness; and the deaths of those who have endured long weakness. And since the conjunction was in the air sign of Aquarius it signified great cold, heavy frosts, and thick clouds corrupting the air; and since this is a sign which represents the pouring out of water, the configuration signifies that rivers will burst their banks and the sea flood. And because of the persistently cold atmosphere bitter humours cannot be expelled from the sea as usual, and because of the persistent cold there will be few fish in the sea and those that there are will rot because of the cold, which traps vapours and humours in their bodies. For his part, Mars in that sign denotes strife among men, and sudden death which comes among all sorts of men, especially among children and adolescents, and illnesses entailing fevers and the spitting of blood, and also violent death and ulcers.

59. THE DANGERS OF CORRUPTED AIR, BENGT KNUTSSON

This account is taken from the treatise of Bengt Knutsson, a mid-fifteenth-century bishop of Vasteras, near Stockholm. Knutsson took over wholesale one of the most popular plague tracts of the fourteenth century, that of John Jacobus (Jean Jacme), written c. 1364. Jacobus was a royal and papal physician and Chancellor of Montpellier, and the various autobiographical references later in the work refer to him, not to Knutsson.

This extract represents a little over half the treatise; the last two sections (on the comforts of the heart and blood letting) have been omitted. The text is taken from a fifteenth-century English translation of Knutsson. I have modernized the spelling and made a few grammatical changes for the sake of clarity, but have not attempted a complete modern Ôtranslation'.

A Little Book for the Pestilence, Manchester, 1911, a facsimile of a printed English translation of Knutsson in the John Rylands Library, Manchester.

Here begins a little book which treats and rehearses many good things necessary for the infirmity and great sickness called the Pestilence, the which often infects us, made by the most expert doctor in physic the Bishop of Arusiens in the realm of Denmark.

At the reverence and worship of the blessed Trinity and of the glorious Virgin St. Mary and for the conservation of the common weal, as well for them that be whole as for remedy of them that be sick, I the Bishop of Arusiens in the realm of Denmark, doctor of physic, will write by the most expert and famous doctors, authorities in physic, some things about the infirmity of pestilence which daily infects us and soon suffers us to depart out of this life.

First I will write the tokens of this infirmity..Secondly the causes whereof it comes..Thirdly the remedies for the same..Fourthly comfort for the heart and the principal members of the body..Fifthly when it shall be the season to let blood..

First as I said the tokens of this infirmity. Seven things ought to be noted here:

The first is when on a summer's day the weather often changes, so in the morning the weather appears rainy, afterwards it appears cloudy and finally windy from the south.

The second token is when in summer the days appear all dark and look like rain, and yet it does not rain. And if many days continue thus, great pestilence is to be dreaded.

The third token is when there is a great multitude of flies upon the earth, then it is sign that the air is venomous and infected.

The fourth token is when stars often seem to fall, then it is a token that the air is infected with much venomous vapour.

The fifth token is when a blazing star is seen in the sky, then it should fortune that soon after there will be great manslaughter in battle.

The sixth token is when there is great lightning and thunder, namely out of the south.

The seventh token is when great winds blow out of the south for they be foul and unclean.

Therefore when these tokens appear great pestilence is to be dreaded, unless God of his mercy will remove it.

The pestilence comes of three things. Sometimes it comes from the root beneath, at other times from the root above, so that we may feel sensibly how the change of air appears to us, and sometimes it comes of both together: from the root above as well as from the root beneath - as when we see a siege or privy next to a chamber or any other particular thing which corrupts the air in substance and quality, which is a thing which may happen every day. And thereof comes the ague of pestilence. And many physicians are deceived about this, not suspecting this ague to be a pestilence. Sometimes it comes of dead carrion or the corruption of standing waters in ditches or sloughs or other corrupt places, and these things are sometimes universal and sometimes particular. By the root above is meant the heavenly bodies, by whom the spirit of life is corrupted in man or beast. In like wise, as Avicenna says in his fourth book, by the form of the air above the bodies beneath may be infected.

For the inspissation above corrupts the air and so the spirits of man are corrupted. This infirmity comes also from the root above or beneath: when the inspissation above corrupts the air or when the putrefaction or rotten carrion of the vile places beneath cause an infirmity in man. And such an infirmity is sometimes an ague, sometimes an apostume or a swelling and that is in many things. Also the inspissated air is sometimes venomous and corrupt, hurting the heart so that nature is grieved in many ways, but so that he does not perceive his harm. For the urine appears fair and shows good digestion, yet nevertheless the patient is likely to die. Wherefore many physicians, seeing the urine of their patients, speak superficially and are deceived. Therefore it is necessary that every patient provide himself with a good and expert physician.

These things before written are the causes of pestilence; but about these things two questions are asked. The first is why, within one town, one man dies and another does not. Where men are dead in one house, in another house no one dies. The other question is whether pestilence sores are contagious. To the first question I say that it may happen for two causes: that is to say because of the thing that does or the thing that suffers. An example of that thing that does: the influence of the bodies above affects that place or that place more than this place or this place. And one patient is more disposed to die than another. Therefore it is to be noted that bodies inclined to be hot have open pores, whereas infected bodies have the pores stopped with many humours. Where bodies have open pores, as in the case of men who abuse themselves with women or often have baths, or men who are hot with labour or great anger, they are the more disposed to this great sickness.

To the second question I say that pestilence sores are contagious because of infectious humours, and the reek or smoke of such sores is venomous and corrupts the air. And therefore one should flee such persons as are infected. In pestilence time nobody should stand in a great press of people because some man among them may be infected. Therefore wise physicians visiting sick folk stand far from the patient, holding their face towards the door or window, and so should the servants of sick folk stand. Also it is good for a patient to change his chamber every day and often to have the windows open against the north and east and to spar the windows against the south. For the south wind has two causes of putrefaction. The first is it that makes a man, whether whole or sick, feeble in his body. The second cause is as it is written in Aphorisms chapter 3, the south wind grieves the body and hurts the heart because it opens man's pores and enters into the heart. Wherefore it is good for a whole man in time of pestilence when the wind is in the south to stay within the house all day, and if it shall be necessary for a man go out, yet let him abide in his house until the sun be up in the east and passing southward.

Here after follow the remedies for the pestilence.

Now it is to be known by what remedies a man may preserve himself from the pestilence. First see the writings of Jeremiah the prophet that a man ought to forsake evil things and do good deeds and meekly confess his sins, for it is the highest remedy in time of pestilence: penance and confession to be preferred to all other medicines. Nevertheless I promise you verily it is a good remedy to void and change the infected place. But some may not profitably change their places. Therefore as much as they can they should eschew every cause of putrefaction and stinking, and namely every fleshly lust with women is to be eschewed. Also the southern wind, which is naturally infective. Therefore spar the windows against the south in like wise as it is said before, until the first hour after the middle of the day then open the windows against the north. Of the same cause every foul stench is to be eschewed, of stable, stinking fields, ways or streets, and namely of stinking dead carrion and most of stinking waters where in many places water is kept two days or two nights. Or else there be gutters of water cast under the earth which cause great stink and corruption. And of this cause some die in that house where such things happen, and in another house die none as is said afore. Likewise in that place where worts and cabbages putrefy it makes a noisome savour and stinking. For in likewise as by the sweet odour of balsam the heart and the spirits have recreation, so of evil savours they be made feeble. Wherefore keep your house that an infected air enter not in, for an infected air most causes putrefaction in places and houses where folk sleep. Therefore let your house be clean and make clear fire of wood flaming. Let your house be made with fumigation of herbs, that is to say with leaves of bay tree, juniper, uberiorgani [unidentified] it is in the apothecary shops, wormwood, rue, mugwort and of the wood of aloes which is best but it is dear. Such a fume taken by the mouth and ears opens the inward parts of the body. Also all great repletion is to be eschewed because full bodies be easily infected as Avicenna says in the fourth canon: they that charge their bodies to repletion shorten their life.

Also common baths are to be eschewed, for a little crust corrupts all the body. Therefore the people as much as is possible is to be eschewed, lest of infectious breath some man be infected. But when the multitude of people may not be eschewed, then use the remedies following. In the morning when you rise wash a little rue and one or two filbert nuts clean and eat them, and if that cannot be had then eat bread or toast sopped in vinegar, namely in troublous and cloudy weather. Also in the time of pestilence it is better to abide within the house for it is not wholesome to go into the city or town. Also let your house be sprinkled especially in summer with vinegar and roses and with the leaves of the vine. Also it is good to wash your hands oft times in the day with water and vinegar and wipe your face with your hands and smell to them. Also it is good always to savour sour things. In Montpellier I might not eschew the company of people for I went from house to house because of my poverty to cure sick folks, therefore bread or a sponge sopped in vinegar I took with me holding it in my mouth and nose because all sour things stop the way of humours and suffer no venomous things to enter into a man's body and so I escaped the pestilence, my fellows supposing that I should not live. These forsaid things I have proved by my self:

60. EARTHQUAKES AS THE CAUSE OF PLAGUE

This is the final section of a treatise usually known, from its opening words, as Is it from divine wrath that the mortality of these years proceeds. It was probably produced in Germany in the generation after the 1348-49 outbreak. In the first part of the treatise, not printed here, the author considers various explanations of the plague, including the astrological one - which he rejects on the grounds that similar conjunctions occur frequently without being followed by plague, and that the configuration of the heavens should have an equal impact on all mankind, which the plague did not. He then turns to his preferred explanation: that the earthquakes of 1347 released poisonous fumes into the atmosphere.

Karl Sudhof; Festschriften aus den ersten 150 Jahren nach der Epidemic des Ôschwarzen Todes' 1348: XI, Archiv fur Geschichte der Medizin XI, 1918-19.

There is a fourth opinion, which I consider more likely than the others, which is that insofar as the mortality arose from natural causes its immediate cause was a corrupt and poisonous earthy exhalation, which infected the air in various parts of the world and, when breathed in by people, suffocated them and suddenly snuffed them out. I can bring two pieces of evidence in support of my proposition, both securely grounded in natural science. The first is that when air which is full of vapours and earthy fumes is enclosed and shut up for a long time in the prison of the earth it becomes so corrupted that it constitutes a potent poison to men. This is especially marked in caverns or deep inside the earth, where there is no fresh air supply, as is often seen in the case of wells which have been unused for a long time and have remained sealed up for many years. For when such wells are opened in order to be cleaned out it often happens that the first man to enter is suffocated, and sometimes in turn those who follow him. And the common people are so ignorant that they blame this on a basilisk lurking inside.