Basic Conditions for Bubonic Plague in Medieval Europe

PART THREE BASIC CONDITIONS FOR BUBONIC PLAGUE IN MEDIEVAL EUROPE

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access CHAPTER THREE

RATS

Introduction: How to Study Rats in History

Advocates of alternative theories on the microbiological nature of historical plague epidemics insist triumphantly that there was no murine basis in the form of black rats in Europe at the time (see below). Th ey concede that there could have been a signifi cant presence in Southern Europe and along the Mediterranean coasts, especially in the urban centres, but elsewhere in Europe, they maintain, there could only have been an incidental and transitional presence caused by ship transportation and they deny that the black rat could have had a per- manent presence in Northern Europe. All of these scholars agree that black rats play a crucial role in epidemics of bubonic plague. Th us, the opposite is obviously true: if there were no or only a tiny presence of black rats in medieval Europe restricted to the southern and Mediterranean parts of the Continent, there could not have been epidemics of bubonic plague, or there could not have been more than the occasional small outbreak in the southern parts of it. It is also generally agreed that the brown (or grey) rat did not arrive in Europe until the early eighteenth century.1 Consequently, if there were rats in medieval Europe, they would have to have been black rats. Th is does not mean, as the zoologist D.E. Davis asserts, that black rats are the cause of bubonic plague.2 Th ese rats have lived peacefully with human beings for thousands of years. Rats are principally victims of bubonic plague. As soon as their dead bodies start to loose temperature, their fl eas begin to desert them, fl eas which have satiated themselves on septicae- mic rat blood and can transmit the real cause of bubonic plague to human beings, namely infective and lethal doses of the bacterium

1 See, Zinsser 1934/1985: 200; Hirst 1953: 123, 142; Twigg 1984: 75; Davis 1986: 456; Audoin-Rouzeau 1999: 423, asterisked footnote. In a personal communication by e-mail of 10 January 2006, Anne Kristin Huft hammer of the Zoological Museum of the University of Bergen, Norway, has confi rmed to me that this arrival date for the brown rat is still generally accepted. 2 Davis 1986: 455.

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Yersinia pestis. Methodologically, necessary conditions and causes are very diff erent matters and should also be sharply diff erentiated from suffi cient conditions and causes. Methodology is not Davis’s strong suit, as will unavoidably be shown below. Th en there is the question whether or not the brown rat played a part which may aff ect our understanding of medieval and early-modern plague epidemics. In his “review” of my monograph on the Black Death, Cohn rejects my view that, according to the IPRC’s reports, the black rat was of paramount importance in the aetiology and epidemiology of plague in India: However, he [Benedictow] has read these reports selectively. For instance, he maintains that the black rat (Rattus rattus) was responsible for plague in the years 1346 through 1353 as well as during the 20th century, but the Indian plague researchers found as many dead brown rats as black ones in dwellings where infection was active.3 Cohn’s accusation warrants a closer look at the IPRC’s conclusion as to the relative importance of the brown rat (today called Rattus norvegi- cus, until 1910 Mus decumanus) and the black rat (today called Rattus rattus, until 1910 Mus rattus): In Bombay city Mus rattus and Mus decumanus both occur in prodigious numbers, in the country villages, however, Mus decumanus is very rarely found. Mus rattus in Bombay is essentially a house rat […] it may almost be said to be a domesticated animal. Mus decumanus, as is well known, is a rat which lives for the most part outside houses in sewers, storm-water drains, stables, etc. Mus rattus is apparently much more common in Bombay than Mus decumanus […]. It is necessary at the outset to insist upon the fact that in Bombay City there is a Mus decumanus epizootic and a Mus rattus epizootic. […] there cannot be the slightest doubt that the place-infection of man is intimately related to that of M. rattus […] that M. rattus is essentially a house-rat and that it lives in close association with man. It necessarily follows from this association that the place-infection of M. rattus must correspond closely to that of man in the sense that both must be referred to inhabited buildings. We think it justifi able to conclude that the epidemic is directly attributable to the rattus epizootic.4

3 Cohn 2005: 1354. 4 IPRC 1907g: 743, 746–7, 752, 766–7.

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Th is proves that IPRC researchers were of the opinion that the plague epidemics were mainly or wholly a refl ection of epizootics among black rats; in the countryside where the brown rat was very rare, the epidemics in the villages would be about entirely based on the black-rat epizootic. Th is demonstrates also that bubonic plague epidemics can develop and spread on the basis of the black rat alone, a fact that under- lies the conclusion that historical plague was bubonic plague. Also in Mumbai where the brown rat had a substantial presence the epidemic was predominantly based on the epizootic among black rats. As can also be seen, the black rat was apparently much more common in Mumbai than the brown rat, and since the brown rat was also largely an out-of-door rat, its signifi cance for the epidemic process would unavoidably be relatively small. Cohn’s assertion that the IPRC found as many dead brown rats as black rats in the dwellings of people in India is spurious. Th is is confi rmed by G. Lamb in his summary of the Commission’s work to May 1907 which is an excellent source for reli- able information on the Commission’s fi ndings and views in the early years.5 Clearly, Cohn misrepresents my view.6 Th us the relationship between the rat plague epizootic and human plague epidemic in India must have been very much the same as in historical plague epidemics, if they were indeed epidemics of bubonic plague. Having clarifi ed this point, we can now focus on the presence and distribution of the black rat in medieval and early modern Europe. Leading plague researchers such as Hirst, Pollitzer, Wu Lien-Teh, and J.J. van Loghem who studied the bubonic plague epidemics of the fi rst half of the twentieth century argue for a broad presence of the black rat in medieval Europe. Th is view is based mainly on contemporary medieval and early modern written sources which also contain some drawings. Th eir view is also supported by peculiar epidemiological features of the spread and seasonality of the epidemics that were taken as refl ections of a basis in rats and their fl eas. In support of this conclusion, they emphasized the interval between the fi rst case(s) and the subsequent endemic and epidemic developments, the latency

5 Lamb 1908: 22–3. 6 It is, however, not clear to me what point he is trying to make, since it is quite generally believed, as mentioned above, that the brown rat did not arrive in Europe until around 1700.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 76 chapter three period which is a defi ning feature of bubonic plague,7 and the strong tendency of epidemics to break out in the warmer seasons and disappear or be substantially diminished by cold weather, which they explained, on the basis of the fi ndings of the IPRC and other scholars, through the role of rats and their fl eas.8 When Davis refers to Hirst’s monograph and write “that a search for evidence to support these statements [as to the presence and role of rats] produces nothing,”9 this is not correct and also his reference to page 119 is wrong, since this matter is not discussed on this page. Further, his reference to a single page, when in fact Hirst addresses the matter broadly over quite a number of pages elsewhere in the monograph, can also produce an incorrect impression, because Hirst has not taken this question lightly as Davis’s remarks suggest (see below). Since all medieval European references to house rats, both textual and graphical, as a present type of animal clearly refer to black rats, the discussion must address the question of whether or not black rats were present in suffi cient numbers and with a suffi ciently widespread geographical distribution to constitute the basis for bubonic plague epidemics. Advocates of theories that historical plague epidemics were not bubonic plague but were caused by some alternative microbiological agent assert, as mentioned above, that there either were no rats at all (so Scott and Duncan, with an incorrect reference to Twigg10 and Gunnar Karlsson11) or that the presence of black rats was restricted to a tiny and transient incidence in urban centres, “if it existed at all” (so Davis and also Twigg, who fi rst advocated this view, and who is supported by Scott and Duncan12). Cohn accepts that black rats were present with some unspecifi ed incidence, but maintains that they were not involved in plague epidemics, since dead rats are not mentioned in such circumstances.13 On the fi rst page of his monograph, he declares that “No contemporary evidence links the Black Death or its

7 See below: 279–88. 8 See for instance Hirst 1953: 121–9. 9 Davis 1986: 456. 10 Scott, Duncan and Duncan 1996: 18; Scott&Duncan 2001: 261, 262, 280–1, 357. 11 Karlsson 1996: 263–84. 12 Twigg 1984: 75–89; Davis 1986: 460. Scott and Duncan 2001: 55, 57, 108, 134, 317, 357. 13 Cohn 2002: 82.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 77 successive strikes in Western Europe to rats.”14 Th is view is based on three main arguments:

(1) the paucity or absence of references to observations of dead rats in contemporary sources relating to historical plague epidemics;15 (2) the climate in the northerly parts of Europe is too cold for black rats, thus the frequent spread of plague epidemics must be seen as proof that they were not bubonic plague;16 (3) Karlsson and Scott and Duncan maintain that they have proved that plague epidemics in Iceland and the village of Eyam in Derbyshire, England, respectively took place without the presence of rats, which constitute proof that historical plague epidemics were not bubonic plague.

Since the question of the presence of rats in Europe at the time of the plague epidemics is important, these three main arguments by the advocates of alternative theories should be discussed seriously and sat- isfactorily, and this is the subject of this chapter. Karlsson maintains that two fi ft eenth-century plague epidemics in Iceland were pure epidemics of primary pneumonic plague caused by some mutated form of Yersinia pestis, the bacterium that causes bubonic plague, and that this, in his opinion, was the general form of late medieval plague; his theory will be discussed below in a chapter in Part 5. In recent decades an important new source on the history of rats has appeared, namely zoo-archaeology or more accurately archaeological zoo-osteology, the study of animal bones found in archaeological excavations. Bone material of rats constitutes material evidence of the presence of rats with strong evidentiary value. If such evidence is not found or only incidentally found when looked for systematically, this will constitute evidence to the eff ect that there were no rats in medieval society or alternatively that there was only a tiny presence which cannot constitute a basis for the large-scale spread of bubonic plague epidemics, and consequently, the view of the advocates of alternative theories would be vindicated. However, if rat bones are found quite

14 Cohn 2002: 1. 15 Twigg 1984: 83, 111–2; Scott and Duncan 2001: 54–5, 359. 16 Davis 1986: 455–70; Twigg 1984: 57, 86–8, 99–100, 112, 218; Scott and Duncan 2001: 57, 261, 357.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 78 chapter three frequently when looked for as an ordinary part of archaeological excavations of human settlements, and with wide geographical distribution, these advocates’ crucial argument on this point will, on the contrary, be proven invalid. Th e osteological material and perspective will be presented in the last subchapter of this chapter on rats.

Th e Nature of Rats and the Frame of Reference of the Medieval Mind

Clearly, the basic observation with respect to the paucity of references to rat mortality in plague epidemics in historical sources is correct, although as for instance, J.J. van Loghem showed long ago, the silence is not quite as systematic or complete as had been asserted.17 Twigg considers over several pages and with considerable scepticism reports of rat falls associated with bubonic plague.18 However, for several reasons the implications and signifi cance of the relative paucity of observations of dead rats in relation to historical plague epidemics is not at all obvious. As we shall see, relevant studies on rat-plague epizootics associated with plague epidemics have not been considered, and important methodological and source-critical problems have been neglected. In relation to this question, there is a crucial methodological point which the advocates of alternative theories fail to address: the validity of this argument depends on a premise to the eff ect that contemporary sources should be expected to mention dead rats in connection with bubonic plague epidemics, and that this should be quite a regular feature in accounts of those epidemics. Otherwise, this argument becomes an inference ex silentio, an assumption to the eff ect that the failure of sources to mention a phenomenon proves that it did not exist or occur, which is a classic fallacy in the methodology of history and social sciences. Firstly, what medieval sources and medieval chroniclers do and do not mention is a continuous source of disbelief and bewilderment to modern scholars.19 Certainly, medieval man had a very diff erent mental frame of reference for the assessment of the relative importance of various types of contemporary events from that of modern man.

17 See, for instance, Van Loghem 1918 and 1925. Cf. Wu Lien-Teh 1936a: 8–9. 18 Twigg 1984: 25–7. 19 Slack 1985: 34–5.

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In this context, it might suffi ce to mention that many chroniclers do not mention the Black Death, although it can be shown that their city, region and country were fi ercely ravaged by the epidemic.20 Generally, modern historians fi nd it diffi cult to accept that outbreaks of mortal epidemic diseases were “determined by divine providence and that their fi rst cause was supernatural: epidemics were God’s punishment for man’s sin,” which was the usual opinion all through the plague era.21 Also historians fi nd it diffi cult to accept the reality or pre- dictive value of the omens or portents of severe epidemics that contemporaries claim to have observed, for instance, the appearance of a man mounted on a great black horse or a giant striding along, his head far above the roofs of the houses, or the appearance in the night sky of skeletons with swords, hearses, coffi ns, unknown comets and astrologi- cal constellations. It is also diffi cult to accept the causative implication in the assertion that the fi rst victims of plague fell sick aft er people had seen “a vision of a corpse or a dead body carried to the parish [church] there to be buried,” and so on.22 Th us, medievalists have to recognize and relate to the fact that medieval man, on the background of medieval culture: (1) believed in types of epidemic manifestations and causation that today will generally be rejected as superstitious or false; (2) did not take the same interest in strict empirical observation, acute analysis and accurate knowledge (in the scholarly meaning of these terms) and, consequently, would not notice the same phenomena as modern man; (3) did not have the same view of what were important and memora- ble contemporary events as modern man has. Th us, all assertions as to what medieval man should be expected to observe and record must be discussed according to medieval man’s frame of mind and culture and be substantiated according to ordinary

20 See Benedictow 2004: 191–4, and fn. 9 on p. 192, 206–7. 21 Slack 1979: 10. In 1641, John Wright, Jr., published a book called Londons Lamentation. Or a fi t admonishment for City and Countrey, wherein is described certaine causes of this affl iction and visitation of the Plague, yeare 1641, which the Lord hath been pleased to infl ict upon us, and withal what meanes must be used to the Lord, to gaine his mercy and favor, with an excellent sprirituall medicine to be used for the preservative both of Body and Soule. See Cox 1910: 151. 22 See for instance Bell 1951: 1–3; Mullett 1956: 16; Slack 1979: 46; Slack 1985: 34–6, 87–8.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 80 chapter three demands for evidence. If the assertion is that medieval chroniclers should be expected to mention rat falls in connection with plague epidemics, such a subject should be shown to belong to the types of events or topics that chroniclers would consider relevant to mention. Empirical orientation increases with modernity, fi rst slowly but clearly from the Renaissance and the Early Modern Period. In order to understand medieval and early modern sources one must understand the frame of mind and understanding of the medieval and early modern people who produced them. To illustrate the signifi cance of this point: Jean de Venette (c. 1307–c. 1370), one of the most prominent and commonly cited chroniclers on the Black Death, states that “the most surprising fact is that children born aft er the plague, when they became of an age for teeth, had only twenty or twenty-two teeth, though before that time men commonly had thirty-two in their upper and lower jaws together.”23 Th e fact is that young children have twenty milk teeth, while adults have thirty-two teeth including four wisdom teeth. Th e idea that plague should have caused such change is not only at variance with modern genetics, but further, Jean de Venette could easily have tested and corrected it by examining the teeth of infants or young children born before the plague and aft er the plague. isTh is, then, an illustration of the weak empirical orientation even of educated medieval people. To illustrate the signifi cance of the frame of reference for understanding the reality of observed phenomena, we may note that Anton von Leeuwenhoek, who invented the microscope in the 1670s was the fi rst human being to observe microbes, but neither he nor other researchers for 200 years to come persuasively connected such observations with the idea that such creatures could be causal agents of epidemic diseases. Th ey did not link this type of observation to an explanatory idea of disease for the practical reason that they had no frame of understanding and analysis, no theory, that could lead their thoughts and reasoning to a microbiological theory of epidemiology.24 Th is puts in perspective medieval man’s great helplessness in understanding the nature and dynamics of epidemic disease. People observe and explain and act according to what their frames of reference and

23 Th e Chronicle of Jean de Venette 1953: 51. 24 It is true that notions of germs had long been around, but this case history illustrates the lack of real interest in such ideas even aft er they became to some extent test- able by microscopic observation.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 81 understanding permit or in the direction their thoughts are lead by their preconceptions. Th us, in this context, the beliefs and understanding of people in the past in relation to the cause of epidemic disease and mortality must be taken into account. Th e great majority, apparently the overwhelming majority of medieval persons, believed that epidemic mortality was an expression of God’s anger and punishment for their sins, and this view was predominant far into the Early Modern Period.25 Th is belief would not be conducive to observation of natural phenomena and alternative rational interpretations. Th e limited number of learned persons who had acquired knowledge of Hippocratic-Galenic medicine would have understood epidemic disease as a refl ection of the presence of miasma. Miasma was corruption or pollution of the air by noxious vapours containing poisonous elements that were caused by rotting putrid matter, but could also be let out from the ground by volcanic activity or particular constellations of planets. Miasma was spread by wind and could therefore spread speedily, it could enter persons by inhalation or through the pores of the skin. Not until the Renaissance, in the decades around 1500, was this theory of miasma expanded to include the idea that healthy persons could be infected by touching infected persons or objects contaminated by them with miasma (fomites), i.e., a miasmatic- contagionistic theory of cross-infection and epidemic spread, although the idea was for a long time not broadly accepted.26 In the words of C. Creighton, the last champion of miasmatic theory in England, writing around 1890: Th e virus of plague has its habitat in the soil, although it may be carried long distances clinging to other things. In its most diff usive potency it [miasma] is a soil-poison generated […] out of the products of cadaveric decay; in its less diff usive but hardly less malignant potency, it is a soil poison generated out of the fi lth of cattle housed with human beings, or out of domestic fi lth generally […].27 Also, in its medieval form, miasmatic theory allowed in principle empirical observation, but classical medicine’s enormous prestige and medieval man’s weak empirical orientation (in the scholarly meaning of the term) meant that chroniclers and physicians would rather interpret what they saw according to the predictions of classical miasmatic

25 Slack 1979: 10; Slack 1985: 26, 28–9. 26 See, for instance, Hirst 1953: 222–72, and Creighton 1891: 326. 27 Creighton 1891: 173.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 82 chapter three theory than believe their own eyes: several mention rat mortality in connection with the Black Death, but together with mortality among a combination of other animals that are not susceptible to the same disease, such as birds, horses and snakes.28 Since miasma seeped up through the ground, it would also infect animals that spent much time underground like moles, rats or snakes,29 and since miasma was spread by wind, it was a logical corollary that birds would fall out of the sky, bee hives succumb,30 and so on, and this type of miasmatic inference took precedence over empirical observation. A typical example is provided by the account of the Greek historian Nikephoros Gregoras who witnessed the Black Death in Constantinople: […] Th e calamity did not destroy men only but many animals living with and domesticated by men. I speak of dogs and horses, and all the species of birds, even the rats that happened to live within the walls of the houses […].31 Since these accounts mention rat mortality in conjunction with mortality of animals known to be refractory to bubonic plague infection and insusceptible to the same pathogen, they are unusable as evidence of reality and rat epizootics in time of plague, and are rather evidence of contemporary culture and mentality and the presence of rats. Lastly in this context, it seems appropriate to mention the almost complete neglect of miasmatic theory by Scott and Duncan in their monographs: in the fi rst monograph the term does not appear in the index, and in the popular version of the monograph of 2004 the word miasma is not mentioned.32 Th ey just assume that contemporary notions of contagiousness can be understood in the light of the modern concept, presumably because this anachronistic approach serves their line of argument. In their original paper of 1996, they mention miasma, but apparently without understanding the concrete contemporary implications.33 An even more demonstrative instance of this

28 Hirst 1953: 127; Wu Lien-Teh 1936a: 8. 29 See for instance Creighton 1891: 173. 30 Twigg 1984: 215. 31 Cited by Bartsocas 1966: 395. 32 See also below: 613–9. 33 Scott and Duncan 1996: 19. Strangely, they do not seem to understand that, according to the theory of miasma, it could be useful to put unslaked lime in plague graves, since it would hasten the decomposition of the bodies and counteract the development of miasma that could seep up through the soil and poison the air. Th e notion that the use of unslaked lime indicates anthrax is an anachronistic interpretation based

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 83 neglect is their citation from Daniel Defoe’s book on the Great Plague in London where he describes in dramatic literary terms the notion of miasmatic-contagionistic spread of plague by diseased individuals. Whilst Defoe wrote this book in quite a journalistic way, hoping to earn some money in a climate of renewed fear of a plague outbreak, they present his account as proof of his great insight and judgment to the eff ect that he describes modern ideas of infection. Th is provides them with yet another opportunity to express their generally disparaging views of historians and medical scholars (the italics are mine): And yet for the whole of the twentieth century, going completely against common sense, it was universally and unequivocally believed that all the plagues were caused by a disease of rodents called bubonic plague, and that the infection was transmitted to people from rats by fl eas. Rats and fl eas are the established dogma of all history books today. What a pity that little attention has been paid to Defoe’s observation.34 Characteristically, “Debunking History” is the disparaging name of the chapter where this statement is found; the authors scorn historians (and physicians) of plague research for collectively “going completely against common sense” and for collectively being blind supporters of dogmatic beliefs. Defoe was born in 1660; he was fi ve years old at the time of the year of the Great Plague, and his book A Journal of the Plague Year was published fi ft y-seven years later. Th e assertion that “Daniel Defoe had perspicaciously noted” the purportedly splendid observations that they attribute to him is obviously untenable and misleading and constitutes no reasonable basis for their disparaging remarks against historians. Defoe was not a scholar or writer of popular science, but mainly a literary author with clear commercial motives whose inaccuracies are legion. In fact, Defoe’s description of the contagiousness of diseased individuals is entirely compatible with and based on contemporary miasmatic theory. Since Scott and Duncan have apparently failed to note this, it seems that they do not have satisfactory knowledge and competence in historical medicine and epidemiology. Th e use of the term “common sense” as a superior substitute for scientifi c observation is also noteworthy. Evidently all scholars who have conscientiously and systematically applied scientifi c methodology and

on modern knowledge and usage. For the same reason, it was also usual to burn live- stock which had died from murrain: see below: 580. 34 Scott and Duncan 2004: 165–6.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 84 chapter three empirical observation to their work and made these the basis of their results should have substituted it with “common sense.” Cohn brushes brusquely aside sound studies of contemporary notions of miasma in order to assert much the same (anachronistic) understanding of medieval man’s notion of contagiousness as Scott and Duncan.35 Carmichael has, as mentioned above, since taken Cohn and also Scott and Duncan to task in a good review essay on this point.36 Since bubonic plague, as shown above, is caused by great numbers of rat fl eas departing quite close in time from dead rats, many members of households or inhabitants of adjacent houses would contract the disease more or less simultaneously. Th is was also observed by early plague researchers: “[…] when two or more [plague] cases occur in a house, they are attacked practically simultaneously as if from a common source of infection.”37 Th us, the epidemic scene of bubonic plague would readily lend itself to miasmatic and miasmatic-contagionistic understanding under the assumption of simultaneous contamination by polluted wind or multiple social contacts with a contaminated person. Contemporaries entertained also notions that were closely linked with superstition like the belief in the reality of the evil eye, that healthy people were easily infected by the look of diseased persons. In connection with the Black Death, several chroniclers and commentators ven- ture outside miasmatic epidemiology in this way, insisting that “merely through looking, one person caught it from the other,” which can, of course, support notions of great speed of spread and be taken as confi r- mation of miasmatic epidemiology.38 Since this chapter is not about contemporary notions of contagion and the spread of epidemic disease, this subject cannot be developed further here. However one should keep in mind that since, in contrast to the claims of Scott and Duncan and Cohn, medieval and early modern man did not know that epidemic disease could be spread and transmitted by insects, they had no alternative to the understanding of contagion and transmission of disease off ered by miasmatic theory (or contamination by look).

35 See for instance Cohn 2002: 114. 36 Carmichael 2003: 253–66. 37 Lamb 1908: 67; IPRC 1907i: 881. 38 See for instance Benedictow 2004: 236.

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Th e Question of the Presence of Rats and the Methodological Fallacy of Inference ex silentio

Th e advocates of alternative theories contrast the paucity or lack of evidence of dead rats in historical plague epidemics with assertions to the eff ect that this was a conspicuous feature of modern epidemics of bubonic plague. However, these assertions are typically not accompa- nied by references to corroborating scholarly studies, but refl ect instead what these advocates of alternative theories consider to be self-evidently true, what must have been the case. Th ey all avoid asking the crucial methodological question: on what grounds should people in the past be expected to observe intense rat mortality or at least substantial numbers of rat falls preceding the outbreak of plague epidemics and running concurrently with the epidemics as they unfolded? Th ese researchers are thus committing a methodological fallacy, the fallacy of inference ex silentio, which is to infer from silence in the sources that a phenomenon or event did not exist or occur.39 Twigg, who generally functions as the pioneer of alternative theories, presenting seemingly important arguments that are eagerly picked up by others, is also the fi rst advocate of alternative theories who commits this fallacy of inference ex silentio. He claims that if rats were present when bubonic plague arrived in 1348 there would have been heavy rat mortality, a fact well known and commented upon by people in endemic plague areas, and as this would have been experienced by the English then that fact alone would have been an important feature of the times. So far as I can fi nd there was no occasion when this was recorded in the British Isles in 1348–50.40 Th is statement contains unsubstantiated and therefore arbitrary assertions as to what people at the time must have seen and what they should have commented on in writing. It contains also an arbitrary argument of fact in so far as Twigg asserts that heavy mortality of rats during plague epidemics was a “fact well known and commented upon by people in endemic plague areas” which is left unsupported by any corroborative evidence or references in the text or in accompanying footnotes. Th e lack of support is not accidental or fortuitous, for these assertions

39 Cf. Benedictow 2004: 192 and fn. 9. 40 Twigg 1984: 111–2.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 86 chapter three as to what people should have seen are misconceived (as we shall see), but they do have a function: they clear the ground for using them as the basis for inference ex silentio that concomitant rat plague did not occur in medieval plague epidemics. When Cohn states on page 1 of his monograph that “No contemporary evidence links the Black Death or its successive strikes in Western Europe to rats,”41 also he commits an obvious fallacy of inference ex silentio, because he claims that such accounts or “links” should have been made by contemporaries without addressing the question of why contemporary people should be expected to note the role of rats and record it in writing. Cohn commits this fallacy of methodology again when he states: “To date, no one has found a description of a rat epizootic preceding or accompanying a plague in late-medieval or early modern Western Europe.”42 He believes that this provides him with another occasion to denigrate historians, stating: “As for the absence of rats associated with the medieval plague, historians have asked us to believe that their ubiquity made them invisible, even though they were noticed in moments other than plague.” He then goes on to cite “the English chronicle of Henry V” where it is related that the besieged inhabitants of Rouen were so desperate from hunger that they ate “all thair cattis, hors, houndis, rattis, myse.”43 Obviously, these two situations are not in pari materia, they cannot be compared in this regard: the English chronicler has a motive to mention rats, he wished to emphasize the English victory, and thus said that the French citizens were forced by the brave English besiegers to degrade themselves by eating animals usually never touched for food. Th is does not imply that contemporary chroniclers generally had a motive for mentioning dead rats in connection with plague epidemics if they were bubonic plague. However, it does contain evidence that (black) rats were present in this north-western French city in numbers making them usable for supple- mentary nourishment, and this was evidently acceptable as true by all readers of the chronicle, which is at variance with the insistence of the advocates of alternative theories that only tiny numbers of rats were incidentally and transitorily present in these parts of Europe, a point Cohn does not refl ect on.

41 Cohn 2002: 1. 42 Cohn 2002: 22. 43 Cohn 2002: 82.

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Th e fact that Twigg is unable to support his assertion that people usually observe heavy mortality among rats during plague epidemics casts sinister shadows over Scott and Duncan’s repeated assertions to the same eff ect in their monographs, for instance, that Since bubonic plague is a disease of rodents, the arrival of an outbreak is frequently presaged by rats dying in the streets […].44 It has been regularly reported that the start of an outbreak of bubonic plague spreading to humans is presaged by rats dying in the streets; in a small village perhaps just a few, in a large South African township perhaps many barrowloads. And yet it is generally agreed that there is no mention in any of the accounts of rat mortality during the epidemics in the age of plagues in Europe.45 Th us Scott and Duncan also claim that dying or dead rats in the streets were a regular feature of bubonic-plague epidemics. However, it is a very conspicuous feature of this assertion of a fact purportedly based on frequent or regular observation that it is supported only by one reference to purported observations in a South African township. Th is is obviously very weak support for a sweeping comparative assertion on a purportedly central feature of contemporary bubonic plague as well as historical plague epidemics, actually they refer to it at least four times.46 Obviously, even if it were correct it is not an adequate basis for the crucial generalizing claim of the high frequency or regu- larity of this phenomenon. However, as we will see below, it is not correct. Scott and Duncan cross the line into this fallacy again in their second monograph of 2004 when they state disparagingly of historians: it is generally agreed that there is no mention in any of the accounts of rat mortality during the epidemics in the age of plagues in Europe. One comment was that “Historians have noted that contemporary accounts omit any mention of rat mortality,” but they have chosen to ignore this important point.47 Since they do not provide footnotes or literary references in support of their statements and assertions in the second monograph, it is impossible to know the identity of the person represented by “one comment

44 Scott and Duncan 2001: 359, cf. 54–5. 45 Scott and Duncan 2004: 176. 46 Scott and Duncan 2001: 54–5, 65, 359; Scott and Duncan 2004: 176. 47 Scott and Duncan 2004: 176.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 88 chapter three was,” if this assertion has any basis in reality at all. Th e disparaging remark on historians is, according to the form of the citation from their text, clearly their own, implying that in their view historians in this fi eld of study are generally intellectually dishonest, since they purportedly have collectively chosen to ignore an obvious and important, even crucial fact, and that historians, with their “eyes shut wide open”, have made this choice in order to protect their untenable theories on the microbiological nature of historical plague. It is possible to uncover the basis of these assertions from information supplied in their fi rst monograph of 2001. Here, Scott and Duncan assert that dead rats were swept up by the barrowload in a South African township and that “dead rats littered the streets of an eastern metropolis,” citing “Annotation 1924” and “Liston 1924.”48 Th is is taken almost verbatim, references and all, from A.B. Christie’s general textbook on infectious diseases. Strangely, they insist that their assertion is based on the fi rst edition of Christie’s textbook, published in 1969 which does not contain a chapter on plague; nor does the second edition of 1974. However, the third edition of 1980 contains a non-specialist chapter on plague, quite fl awed, as will be seen.49 Th is chapter contains the account they cite and also important information which they neglect to mention in conjunction with their repeated assertions that dead rats were collected by the barrowful in the streets. Christie’s account of plague in South Africa is inconsistent, even insouciant. He mentions the purported observation in the South African township twice: on page 758, he uses the wording “dead rodents have been collected ‘by the barrowful,’ ” and two pages later he states that rats “may be swept up by the barrowful in a South African township.” It is this second assertion that Scott and Duncan have chosen to contrast with the lack of similar information in relation to historical plague epidemics in Europe and as proof that these epidemics could not have been bubonic plague. However, one page later, Christie notes that in South Africa “167 outbreaks with 372 cases and 235 deaths have been recorded,” revealing that outbreaks comprised, on average, 2.2 cases with 1.4 deaths, which means that plague did not occur in epidemic form but only in weak endemic form. Th is is a pattern that on its own raises very serious doubts that it could be associated with open

48 Scott and Duncan 2001: 65, cf. 55. 49 Below: M400–5.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 89 mass death of rats in a township. Th en Christie adds that “apparently plague has not spread in South Africa via the R. Rattus and X. cheopis combination.” Th is constitutes suffi cient grounds for rejecting the idea that these tiny plague episodes can be associated with dead rats, observable or not, and have any signifi cance for the understanding of historical plague epidemics. It can be shown that Scott and Duncan knew these basic facts, but placed them at safe distance from their assertions that rats were collected by the barrowful.50 In support of their various assertions on this point, Christie/Scott and Duncan refer to “Annotation. Reservoir of plague in South Africa,” published in Th e British Medical Journal, 1924, page 875. However, in this “Annotation” not a word is said about rats, nor is the word barrowful used, and in particular, nothing is said about collection of rats or other rodents according to this gauge or any other measure. Instead, it mentions that wild rodents called gerbilles play the main part in con- stituting a weak plague focus in South Africa. Rare human cases of plague are mainly associated with plague among these rodents or occasionally with some other wild types of rodents. Gerbilles avoid “human habitation,”51 a fact which explains the miniscule incidence of human cases of plague and also associates the incidence of such cases with rural localities and makes it diffi cult to relate observations of great numbers of these plague-dead rodents to townships. However, sud- denly or inadvertently Scott and Duncan mention that all “367 [sic] human cases” “were confi ned to the villages,” in short, human cases occurred episodically and were not associated with townships, streets and urban structures but with rural society and African village-structures.52 Th is shows that they were aware that there were only incidental cases of plague in South Africa. Th e assertion that rats were collected by the barrowful in a South African township is false. It is this false assertion of the observation of barrowloads of plague-dead rats in South African townships which allows Scott and Duncan to construct a contrast with the lack of similar information in historical plague epidemics in Europe and to consider the diff erence as proof that the historical epidemics could not have been bubonic plague. Th e fictitious character of the fi rst half of the comparison invalidates the comparison and the inference. One should keep in mind that the other half of the

50 Scott and Duncan 2001: 50. 51 Wu Lien-Teh 1936b: 197. 52 Scott and Duncan 2001: 50. No source reference given.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 90 chapter three comparison is also unsupported by evidence, a point that will be discussed below. Th e brief statement about rats that “litter a street of an eastern metropolis” given by Scott and Duncan is intriguing. Th ey refer to a paper by Liston; however, the statement and supporting reference are taken directly from Christie.53 Unfortunately, Liston’s paper consists of lectures and is unannotated. It contains one passage that could possibly be the source of Christie’s/Scott and Duncan’s account: “It is stated that as many as 20,000 dead rats were collected in a short time in certain quarters of Hong-Kong, and that 1,500 were obtained from a single street.”54 One should note two aspects of this account: fi rstly, the unspecifi c nature of the opening words may indicate a reservation or a second-hand origin, and secondly, nothing is said to the eff ect that rats littered the streets, only that dead rats were collected, also the second part of the passage fi ts into this framework. All standard works on plague have been searched for corroboration of this information, but nothing was found bearing directly on Liston’s remarks even in the standard work published by the National Quarantine Service, Shanghai Station, by the outstanding scholars Wu Lien-Teh, J.W. Chun, R. Pollitzer et al., Plague. A Manual for Medical and Public Health Workers. Some remarks in the historical introduction could be of interest. It is related that a person called Dr Mary Niles “tells of a Chinese offi cial at Canton” who in 1894 off ered to pay out of his own pocket “ten cash” for every dead rat brought to him and collected over 35,000 in the course of a few months. On elementary source-critical grounds, the incidental and uncertain nature of this piece of information is quite obvious and it does not relate to the metropolis specifi ed by Liston.55 It is mentioned in an early standard work on plague that in 1901, thirty men were employed in Hong Kong to collect rats, and “a private fi rm of 30 coolies employed in sorting, and one of whose duties was to collect dead rats from the godown when required,” and that in another fi rm rats were dying in the store-room and two men were engaged in remov- ing them.56 Conceivably, this could be the background of Liston’s remarks, but if so, it cannot be considered evidence bearing upon the point, at least not signifi cant evidence: both cases relate to attempts at

53 Christie 1980: 760. 54 Liston 1924: 950. 55 Wu Lien-Teh 1936a: 21. 56 Simpson 1905: 217.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 91 reducing the rat population by payment for dead rats or organizations for the collection of dead rats in Canton and Hong Kong. It is not stated that the rats were picked up in the streets, and thus many may not have died by plague, but could have been killed for cash or were picked up or caught in godowns, store rooms or other storage facilities. To my knowledge, evidence of mass deaths of rats is at best sparse or almost non-existent not only in relation to historical epidemics of plague but also in relation to modern epidemics, which explains that only Scott and Duncan attempt to refer to such evidence, erroneously as has been shown. Accounts of purported observations of mass death of rats in plague epidemics in India in the 1830s are mentioned, but these observations were not available in the form of scientifi c studies.57 Taking a closer look at the few accounts or assertions of observations of widespread rat mortality associated with bubonic plague epidemics, it becomes clear that they are not based on scientifi c studies but on reports written on obsolete miasmiatic premises, are presented in an untestable or inaccurate form, have the character of hearsay or rumour, or relate to special circumstances that do not clearly imply widespread or mass occurrence of dead rats in streets or other types of open public spaces. It appears impossible to corroborate on the basis of scholarly studies that easily observable mass mortality of rats has occurred either in connection with modern epidemics of bubonic plague or with historical plague epidemics. Th ere is a conspicuous paucity of relevant evidence on this point and its problematic nature must be underscored. Th is raises the question of why this should be so.

Ars Moriendi Rattorum: Where Have all the Dead Rats Gone?

Modern plague research started with the outbreaks of plague in Canton and Hong Kong in 1894 which showed that the disease had retained its ability to cause enormous mortality;58 it had also retained its great ability to spread from commercial hubs by ship to countries abroad, as had been demonstrated with enormous vigour by the Black Death.59 In a few years, plague was transported to India, Australia, Indonesia,

57 Hankin 1905: 55. Cf. Simpson 1905: 43, 46. 58 Hirst 1953: 103; Yersin 1894: 662. 59 Benedictow 2004: Map 1, p. xviii–xix, 60–229.

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Madagascar, Egypt, the U.S.A., countries in South America, and so on. Th is menacing development was taken very seriously: national health organizations were mobilized, eminent medical scholars with relevant qualifi cations were organized into plague research commis- sions equipped with fi ne medical laboratories and ample assistant per- sonnel, generous grants fi nanced comprehensive studies of the disease’s microbiological, medical and epidemiological properties in order to develop effi cient anti-epidemic countermeasures at a time when no medication eff ective against the disease was available.60 Th e black rat or Rattus rattus, alias the house rat or ship rat, was quickly singled out as the (main) carrier of the disease. It was pointed out at the very start of modern plague research, in Yersin’s small paper of 1894 summarizing his early fi ndings in Hong Kong, that “it is probable that the rats constitute the main vehicle.”61 Soon it was also sus- pected that its usual rat fl ea was the agent of transmission both between rats and from rats to human beings. Th e Indian Plague Research Commission (IPRC) concluded early on that “the epidemic is directly attributable to the rattus [rattus] epizootic” and that “the rat-fl ea [of the black rat] and the rat-fl ea alone is the agent of transmission of the plague bacillus from rat to man.”62 However, the pioneering plague researchers who started their work around 1900 when little scholarly work had been carried out on rats were soon confronted with an intriguing problem, namely the scarcity or even absence of observed rat falls both under ordinary circumstances and during plague epidemics. In their endeavours to acquire indispensable knowledge of the behavioural patterns of rats, especially severely ill or moribund rats, they had to perform much basic work. Th e IPRC implemented comprehensive studies of natural rat mortality in relatively isolated villages outside Mumbai and in the Punjab. Despite considerable eff orts and opening up of rat holes and burrows, so few rats were found that they had to acknowledge that the fi ndings could not “represent the normal rat mortality and it may, therefore, be inferred that the large majority of rats which die from normal causes die in inaccessible places.”63 Th e IPRC were not unprepared for this conclusion.

60 Hirst 1953: 101–6, 296–300; IPRC. XXII. 1907g: 724–5; Lamb 1908: i–iv; Brygoo 1966. 61 Yersin 1894: 667. My translation from French. 62 IPRC 1907g: 743–62, 767, 777; Lamb 1908: 54. 63 IPRC 1907h: 854; IPRC 1907j: 908; Lamb 1908: 24.

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In 1906, J. Ashburton Th ompson, published, as mentioned above, a paper summarising Australian research aft er bubonic plague had appeared in Sydney in 1900. In this paper he also addresses this phenomenon and the insights gained by the health authorities under his leadership. He contends that the reason that some scholars thought that there were plague epidemics in India without a basis in rat-plague64 was that a proper search had not been performed.65 “Systematic detec- tion of rat-plague is in reality a diffi cult business,” he points out. It was not until a “rat intelligence staff ” had been trained and acquired practical experience in the search for plague rats that they were regularly found in the individual houses in which plague cases had occurred, work that started in 1904. Several reasons for this phenomenon were indicated; apparently the basic or crucial reason is that “Rats eat each other in nature.” When rats become seriously ill or dying and cannot defend themselves, they try to hide away as best they can in order not to be eaten more or less alive by their fellow rats when they are no longer able to defend themselves. Th ey tend to die out of sight in obscure and relatively inaccessible places. Th erefore, finds or reports of sick rats that had come into the open, “could be counted on the fi ngers.” Ashburton Th ompson goes on to enlarge on his findings: Th ey do die in unusual places, and so regularly that we feel justifi ed in regarding the discovery of three or four carcases at a similar stage of decomposition under fl oors, or in, or on the tops of cupboards, etc., during known presence of an epizoötic as probable evidence of death from plague. In ordinary, as is very well known, rats generally die out of sight […]. Even when poison has been laid discovery of several dead bodies in such situations should arouse suspicion.66 Th is makes it clear why it is so important for Cohn to dismiss the fi ndings of Ashburton Th ompson by falsely labelling him racist (see above), that is, because they represent a grave threat to one of the pillars of his theory, and why Ashburton Th ompson’s observations are generally passed over in silence by the other advocates of alternative theories of plague. Th e IPRC had ample occasion to observe that rats eat dead rats and rat fl esh. In their experimental godowns, the Commission observed that dead or dying rats were eaten: “that of 12 rats proved to have died

64 See Hankin 1905: 64, 66. 65 Th e paper was written before the IPRC had commenced publication of its work. 66 Th ompson 1906: 548, 550–1. Cf. Hirst 1953: 147–8.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 94 chapter three of plague, the carcases of nine were more or less eaten,” that the “carcases of four inoculated and seven uninoculated were found to have been eaten, several almost completely,” and “in godown No. 9, many of the carcases were eaten.”67 Th ey also carried out experiments by feeding rats highly infected viscera of dead plague rats or “the whole carcases of their plague-infected comrades” which were readily eaten.68 Th e IPRC made also thorough studies of rat-plague epizootics in selected localities in Mumbai and the Punjab. Again their fi ndings were very similar to those reported by Ashburton Th ompson. In 1908, Lamb, the leader of the IPRC, summarized their fi ndings: In proportion to the severity of the epidemic the number of plague-rats found was very small, notwithstanding the very thorough and extensive search made. Th e experience both in Sion Koliwada [Koliwada is the northerly part of the village Sion outside Mumbai] and in the Punjab village of Dhund in this respect points to the danger of concluding that plague-rats are absent from an infected locality unless a very thorough search is carried out.69 A couple of years later, the IPRC noted the same observation during their study of plague at Belgaum, a small town situated roughly 400 km slightly southeast of Mumbai, where the role of rats was very much in focus and a great program was launched to trap as many rats as possible. Some 39,460 were trapped, while in contrast the number of dead rats obtained being very small indeed […]. Undoubtedly, too, rats may be dying in a house without the inhabitants being aware of the fact. Rats not infrequently die in their burrows, or under cover of boxes or sacks, or amongst rubbish or even in the roofs of the houses.70 A sprinkling of dead plague rats was found in India and China. Th e reason for this appears mainly to be that the black rat is an excellent climber which fi nds Indian and Chinese housing well suited for making their nests in the ceilings, and when seriously ill, the occasional rat would fall down on the fl oor.71 Plague researchers working in an Egyptian village noted that “Dead rats were picked up from the fl oor of

67 IPRC 1910a: 316–7, 318, 321, 324, 326, 331. 68 IPRC 1907a: 373–81; Lamb 1908: 33–6. 69 Lamb 1908: 18, cf. p. 24. 70 IPRC 1910c: 453–4, 456, 469. 71 Pollitzer 1954: 296.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 95 most of the rooms, having fallen presumably from the beams of the ceilings.”72 Ashburton Th ompson’s strong emphasis on the point that local experience in the habits and haunts of rats was essential in order to con- duct successful surveys of rat-plague was a lesson carefully noted by later plague researchers. In 1911, the Department of Public Health of the Egyptian Government appointed a team of British and Egyptian experts on plague research to study plague in Egypt. Th ey made a very thorough study of the rodent populations in selected areas. As soon as plague broke out in a village, the team would move in, see to it that the population was evacuated, and start their investigations. “We fi rst trapped the empty village but did not capture any rats, nor were any dead one seen. Th is result was puzzling in view of the considerable number of human plague cases.” However, they caught truly extraordi- nary numbers of rat fl eas inside the houses which indicated the recent death of a considerable number of rats. Th e explanation was uncovered when two of the houses were torn down and “the rat burrows were exposed and traced. A regular system of nests and burrows existed at the bottom of the walls with free communication at their junctions, an arrangement that indicated continuity along the whole length of each block of houses.”73 When plague broke out in Colombo, Sri Lanka, in 1914, W.M. Philip and L.F Hirst were sent to investigate the epidemic. Keeping Ashburton Th ompson’s advice in mind, they organized an anti-plague staff and set out to uncover the underlying plague epizootic. Th e description of the diffi culties they met with and how they resolved them on the basis of modern knowledge, technical means and a scientifi c approach high- lights the improbability that medieval populations in times of plague could be expected to observe recurring signifi cant rat mortality that would lead to suspicion of a connection with the human plague epidemic. To begin with Philip and Hirst found few dead rats in the open and conspicuous evidence of a rat epizootic was lacking. In order to reveal the presence of dead plague rats it was usually found necessary to open up rat burrows and thoroughly dis- sect the tiled roofs of houses or to force surviving infected rats out of their burrows by pumping Clayton gas fumes into their holes. As the

72 Petrie, Todd, Skander et al., 1924: 129. 73 Petrie, Todd, Skander et al., 1924–5: 129–30.

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anti-plague staff gained experience, the correlation between rat and human plague in space and time became closer and closer.74 Th is presentation of the rat-related plague studies in Sri Lanka by Hirst and Philip and the fi nal citation are taken from Hirst’s standard work on plague and can serve as yet more evidence of why Cohn felt that he had to do away with this work, and hoped that by labelling him racist (see above) he could make scholars turn away from his work. Twigg gives such a skewed presentation of Hirst’s and Philip’s work in Colombo that the central point is completely obscured.75 Th is subchapter on the behavioural pattern of dying rats and the great diffi culties of fi nding rats having died either from normal causes or from plague unless a highly competent and very thorough search has been implemented can be closed with the observations of Dutch scholars in Java and their concluding remarks. J.J. van Loghem and N.H. Swellengrebel met with the same curious absence of rat falls and almost had to completely tear down native huts in order to reveal the rat nests and the presence of dead rats. Aft er great eff orts, they learned, among other things, that the house rats made their nests in the hollow bamboo frames of the huts and also of the beds; rat nests were found in the roofs, between the walls and in the internal wall covering made of thin bamboo sprouts, and so on, and in these places they also found rats dead from plague.76 Th e results of research on rats in plague epidemics in the fi rst decades of the twentieth century are aptly summarized by the Dutch medical scholars C.D. de Langen and A. Lichtenstein:77 Th e most important argument adduced by the opponents of the “Rat- Flea-Man” theory of the distribution of plague is that in various epidemics no rat plague has been observed, or the epizootic has only developed aft er the epidemic has started. A really critical examination of the data in these cases shows in every instance that no suffi cient search was made for the preceding rat plague. In some cases the mere fact that among 100 rats caught in traps no rat plague could be demonstrated was accepted as suffi cient proof that there was no rat plague present! How very diffi cult it is

74 Here I cite the succinct summary by Hirst 1953: 148, of the original text in Philip and Hirst 1917: 542–5. 75 Twigg 1984: 112. 76 Van Loghem and Swellengrebel 1914: 467. See also the photographs in the appendix. 77 De Langen and Lichtenstein 1936: 185–6.

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to demonstrate even a very widespread rat epizootic has been shown in Java where, in spite of the most diligent search, no rat plague could be found, until van Loghem easily demonstrated the wide distribution of the disease among the rats by splitting open the bamboos used in building portions of the native houses. Th e “Rat-Flea-Man” theory as it has now become sharply defi ned in Java, regards the rat plague as an epizootic disease conveyed by fl eas […] it follows that rat plague must always precede human plague; this has almost always been capable of demonstration in Java aft er a careful enough search has been made. At the same time, Wu Lien-Teh pointed out: Modern examples could be quoted where not only the population at large but even the medical men believed rat plague to be absent and yet the presence of an epizootic was demonstrated by a proper search. And he goes on to underline what all the advocates of alternative theories of plague collectively have neglected to take into account: “In old Europe many factors militated against such discoveries.”78 Against this background, the question must be asked: on what grounds should people in the past be expected to have observed intense rat mortality or at least substantial numbers of rat falls preceding the outbreak of plague epidemics and running concurrently with the epidemics as they unfolded? In the preceding subchapter, I showed that the assertions of the advocates of alternative theories that the paucity or lack of historical evidence of dead rats during historical plague epidemics proved that the epidemics could not have been bubonic plague were methodologically fl awed, and have the character of inference ex silentio. In this subchapter, material has been presented that demonstates in the clear- est possible way the invalidity of their inferences ex silentio: dead rats were not seen during historic plague epidemics simply because it is very diffi cult to nd fi dead rats, not because they were not present.79 Finally, it must be permitted to ask how so many studies and comments on this rat-related problem can have been overlooked by the advocates of alternative theories if a proper study of the relevant works on plague research published in leading journals and standard text- books had been performed.

78 Wu Lien-Teh 1936a: 8–9. 79 Cf. Benedictow 2004: 192, and footnote 9.

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Zoobiological and Zoogeographical Arguments on the Question of Signifi cant Presence of Black Rats in Medieval Europe

A central argument concerning the presence of the black rat in Europe is based on the idea that its geographical distribution is determined by the fact that the species originated in a warm region, Burma and India,80 the North African or Arabian parts of the western Mediterranean as well as the eastern Mediterranean81 or more vaguely that it had an “Oriental origin.”82 Twigg and Davis who are zoologists assert in absolute terms that this origin means that black rats are tender and warmth- needing animals and that the climate in the northerly parts of Europe is too cold to be compatible with a signifi cant and widespread presence of this species; at the most there could have been a more or less sporadic incidence due to importation by ship from Mediterranean ports.83 Consequently, historical plague epidemics in these regions must be some other epidemic disease than bubonic plague. Th is argument is embraced by Scott and Duncan and Cohn, presumably because it helps clear the way for their alternative cases.84 In this subchapter, I will therefore address this question as a subject suitable for serious discussion. Some priority will be given to Davis’s paper on the matter, since it appears that this is the most infl uential work in this connection, and also to Twigg’s discussion of this topic, as both are zoologists and operate in this fi eld with some scholarly prestige. Some of the arguments have considerable illustrative powers. Twigg enthusiastically cites a remark by G.M. Th omson who, in a work on the North-West Passage, asserts that the Black Death “struck Greenland even more savagely than Europe.”85 Th omson is neither an historian nor an archaeologist and has no competence on medieval history and no competence on Nordic history, yet Th omson’s assertion permits Twigg to conclude: “It is highly unlikely that Rattus rattus was present there at that time and I can fi nd no records of this species in Greenland in modern times either.” By implication historical plague could not have been bubonic plague. Also this argument is embraced by Scott

80 Pollitzer 1954: 282; Russell and Russell 1983: 102; Twigg 1984: 86. 81 Zinsser 1934/1985: 198; Davis 1986: 456. 82 Hirst 1953: 126. 83 Twigg 1984: 80, 86–7, 100–1; Davis 1986: 455–70. 84 Cohn 2002: 53; Scott and Duncan 2001: 261; Scott and Duncan 2004: 174–5. 85 Twigg 1984: 86–7.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 99 and Duncan who maintain repeatedly that the fact that the Black Death ravaged Greenland and Iceland constitutes proof that it could not have been rat-borne bubonic plague.86 In fact, Nordic scholars, both historians and archaeologists, have taken substantial interest in what happened to Greenland’s Norse population and why it disappeared. Th is research has been thoroughly and comprehensively summarized in English in a fi ne paper by J. Berglund.87 It is also succinctly summarized in English by the Finnish scholar J. Vahtola: “In the late Middle Ages the entire Norse population [in Greenland] disappeared. Th ere is no evidence that epidemics of plague or any other disease caused the desertion.” Th e main explanation of the desertion is ecological: “Recent investigations have demonstrated con- vincingly that the fertility of the soil was ultimately destroyed by cli- matically caused erosion and overgrazing of pastures and meadows. In the face of incipient starvation many of the people may have moved to Iceland.”88 Th is is exactly what is stated on the matter in my monograph on the Black Death.89 Twigg’s and Scott’s and Duncan’s assertions are without foundation in relevant scholarly studies. For the same reason, Scott and Duncan maintain repeatedly that the Black Death raged in Iceland.90 On this point the Icelandic annals are entirely clear: “Th is disease did not come to Iceland.”91 Scott and Duncan state also that the Black Death crossed “the Baltic to Norway,”92 an impossible feat of geographical dissemination. As a matter of fact, the Black Death did not even spread across the Baltic to Sweden (or from Sweden across the Baltic).93 At the heart of Davis’s line of arguments is a series of interacting methodological fallacies. He presents some selected information from modern studies on the brown rat and the black rat and claims that, although most of this information relates to the brown rat, “enough is known of Rattus rattus [the black rat] to permit conclusions about [the rat] populations at the time of the Black Death.”94 Th is is an obvious

86 Scott and Duncan 2001: 6, 81, 98, 108–9, 357. Scott and Duncan refer to the uncritical and poor work of Kohn 1995. 87 See the fi ne summary by Berglund 1986: 113–34. 88 Vahtola 2003: 567–8, 576. 89 Benedictow 2004: 146. 90 Scott and Duncan 2001: 6, 81, 98, 108–9, 357, 374, 376. 91 Islandske Annaler 1888: 276. Lawman’s Annal: “Þessi sott kom ecki aa Island.” 92 Scott and Duncan 2001: 376. 93 Benedictow 2004: 170–8; 196–7, 209–10. 94 Davis 1986: 459.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 100 chapter three instance of fallacious methodology. Historical periodisation is not fortuitous, but refl ects historians’ general view that historical processes have changed societal structures so profoundly over time that they are relating to qualitatively diff erent social formations or societal structures. Th is means that a condition found in one historical period can only provide the basis for a working hypothesis to the eff ect that it also was the case in another historical period and functioned or interacted in much the same way within diff erent social structures. It is a fallacy of methodology to make inferences across the boundaries of historical periods without due consideration to historical and societal changes and a clear argument as to why a specifi c factor should nonetheless be able to operate the same way in the specifi c case under discussion.95 Methodologically, interperiod comparisons or approaches have the character of analogies or parallels which can prove nothing but can serve to construct working hypotheses, while proof requires evidence in the form of empirical data relating to the historical social formation under study. For this reason, observations on aspects of one social formation generally cannot be projected into some other social formation, they can only serve as a base for working hypotheses to the eff ect that these specifi c parts of social reality have not changed with the struc- tural societal transformations. If the case were otherwise, if one could legitimately and freely project aspects of one social formation into other social formations, one could legitimately show that medieval society was identical or similar to Early Modern society or even modern society. Th erefore, only evidence specifi c to the period under discussion can be used for evidentiary purposes with respect to any topic; if there is no evidence, the historian has lost. It should be obvious that the biotopes and ecological niches and environments of rats have changed profoundly and fundamentally, and that there is no profound similarity in these crucial respects that will permit argument for historical similarity over these historical periods. Here we may mention the dramatic zoological eff ects of the introduction of the brown rat in Europe in the eighteenth century on the living conditions of the black rat. Because the brown rat was much stronger and more aggressive, it drove the black rat out of its usual habitats and caused its extinction in many countries and regions (see below). One must also take into account the intensive and fundamental changes of

95 See for instance Benedictow 2004: 387–94; Benedictow 2006: 133–42.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 101 human society with respect to types and distribution of settlement and of building structures and of mentality and culture also in relation to animals and insects, which in modern Western society are strongly aligned against the presence of rats and insects in immediate human proximity. Th ese methodological and sociological remarks should suffi ce to uncover the fallacious and untenable character of Davis’s approach. However, these are the premises that allow Davis to conclude as follows (the enumeration of his assertions is mine): Application of this information to rat populations of the Middle Ages produces the following scenario. [1] Rattus rattus may have persisted in towns, especially grain ports, but the number of buildings with rats was small and the number of rats was stationary. [2] Th e [rat: my insertion] population in a particular town disappeared in few years but might again become established as a result of new introductions. [3] Th ese characteristics held for northern France, Scandinavia, and the British Isles, but [4] in the more southern Mediterranean region of France Rattus rattus may have lived in small numbers in rural areas.96 All four assertions contained in this citation on the presence and role of rats in medieval society are only speculative or hypothetical. Th ey could legitimately be working hypotheses that could be tested and potentially corroborated through the gathering of evidence. However, Davis has adduced no evidence, and thus, proved nothing. Conversion of working hypotheses into assertions of fact and also inference across the dividing lines of historical periods are fallacious. Another typical instance of a methodologically fl awed argument is Davis’s absolute assertion that the black rat lives in trees and roofs of houses […] they rarely if ever inhabit burrows, tunnels in the ground, or aquatic habitats. Th us references to rodents living in burrows or swamps exclude Rattus rattus.97 A number of citations and references has been presented above which demonstrate the burrowing abilities and habits of the black rat in connection with the diffi culties of fi nding rats dead from plague.98 Th e inherent anachronistic fl aw in Davis’s assertion becomes immediately apparent when these assertions are related to Pollitzer’s presentation

96 Davis 1986: 459–60. 97 Davis 1986: 456, 457. 98 Above: 91–7.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 102 chapter three and discussion of rats, where it is stated that “in the absence of Norway rats, R. rattus may live on the ground fl oors or even underground.” eTh point is that in the presence of the bigger and stronger brown rat which aggressively fi ght the black rat for territory, the black rat which is an “excellent climber, prefers to shelter in the upper parts of buildings.”99 Th e same perspective is found in the IPRC’s remarks that in contrast with Mus rattus [= Rattus rattus] in Bombay, the Punjab rat burrows extensively […]. It is almost certain that the rat-burrows in the Punjab villages are very extensive, ramifying beneath and opening up communication between several contiguous houses.100 A Punjab village may be looked upon for our present purpose as being honey-combed with rat burrows which ramify in all directions.101 Mus rattus, although typically a climbing rat [in Mumbai], is able to burrow, e.g., in beaten earth fl oors. We have frequently made this observation and in one instance (in Parel village [outside Mumbai]) have seen exceptionally large and numerous holes and burrows in the earthen fl oor of a store-roome for grain from which many Mus rattus had been trapped.102 In Mumbai where the brown rat is usual, the black rat prefers to live in the upper parts of buildings, in the Punjab they are typical burrowing rodents, since the brown rat “is not found in the villages of this Province.”103 Th e IPRC noted that black rats were burrowing extensively in Belgaum (see above) both outside and inside houses where there were no brown rats.104 Again it can be readily seen that Davis just projects into the past the modern situation and the behavioural eff ects on black rats of the intensely competitive presence of the stronger and more aggressive brown rats, a constellation which did not exist in the Middle Ages or for a long time thereaft er. Th e question of the burrowing of black rats will be discussed below in connection with the history of black rats in the Nordic countries and fi nds of medieval skeletal remains. From an epidemiological perspective it is also important to note Pollitzer’s point which serves to underline the erroneous character of

99 Pollitzer 1954: 290. 100 IPRC 1907j: 905. 101 Lamb 1908: 13. 102 IPRC 1907g: 746. 103 IPRC 1907a: 376. 104 IPRC 1910c: 456.

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Davis’ assertion, namely that “the available evidence shows that X. cheopis has an affi nity for rats living underground rather than for those sheltering on higher levels of the houses.”105 Another important question relates to the issue of the density or numbers of rats in relation to the density or numbers of people in an area, because this relationship concerns the necessary conditions for eff ective spread of bubonic plague epidemics. Twigg and Davis endeav- our to play down the relative number of rats as much as possible in order to undermine a necessary condition for effi cient spread of bubonic-plague epidemics.106 Th e central point which they faile to take into account is that the presence of rats in modern cities and settlements tends to be strongly aff ected by counter-measures by sanitary authorities and extermination campaigns. When Davis studied the rat population of Baltimore in 1947 he estimated their numbers at 200,000, one rat per fi ve inhabitants. However, three years earlier the number had been estimated at 400,000 rats; the rat population in the meantime had been greatly reduced by counter-measures. Th us, again their arguments are based on the fallacy of anachronistically projecting the outcome of modern studies into the Middle Ages. Pollitzer’s following statement is a useful guideline to the question of relative numbers: “Th ere is reason to assume that in less well-sanitated cities, and in smaller settlements in general, the number of rats equals or even exceeds the number of people. Th is is presumably the rule on farms (Tice).”107 Th e IPRC’s study of the rat infestation of Parel village demonstrated beyond doubt that the numbers of black rats in the houses far exceeded the number of human inhabitants.108 In Belgaum, the IPRC trapped a number of rats higher than the human population without exterminating the rat population, so the number of rats clearly exceeded the number of inhabitants.109 I have noted with some interest that the responsible municipal authority in Oslo (Norway) cautiously esti- mates that today the number of rats equals the number of people, despite their eff orts at extermination.110 Generally, from the High Middle Ages and through most of part of the Early Modern Period

105 Pollitzer 1954: 336. 106 Twigg 1984: 88–9. 107 Pollitzer 1954: 292. 108 IPRC 1907h: 844–54. 109 IPRC 1910c: 457. 110 Tollefsen 2005: 7.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 104 chapter three about 85–95 per cent of European populations lived in the countryside on holdings and tenancies of various sizes, each according to local cus- toms with two or more buildings in which colonies of black rats would like to settle: a dwelling house, barn, storehouse, stable, cowhouse, and in addition a cottage to accommodate aging parents and not infrequently “undersettles” (sub-tenancies).111 In the opinion of Davis, it is an important argument that ports can usefully be compared to islands and in order to understand the establishment and persistence of Rattus rattus over time we can follow some principles of island zoogeography. A port can be assumed to have the characteristics of an island because, on the land side, numerous barriers of habitat and frequent hazards prevent rats regularly from spreading far from the wharves. A spread of up to a kilometre or so can nevertheless occur.112 Davis asserts that commercial hubs like Venice, Florence, Genoa, London, Bruges or Lübeck can from a zoogeographical perspective be usefully compared to (more or less isolated) islands. In order to defend this position, Davis resorts to assertions about ports that fl y in the face of the amassed knowledge regarding the functions of urban centres in general and specifi cally also of medieval urban centres, from Max Weber’s classic sociological study of pre-modern cities113 to R.S. Lopez’s classic monograph Th e Commercial Revolution of the Middle Ages, 950– 1350, Pound’s great summary of medieval economic history, and all serious work that has been published on the subject in the last generation. Urban centres do not function geographically as islands in any signifi cant respect but, on the contrary, as centres of communication lines that radiate out from them and also meet in them. Along these communication lines by land or sea or rivers a great variety of goods are transported and people travel with them or with a great variety of baggage and motives. Microbiological agents, insects and animals will imperceptibly move with goods, people, luggage or clothing. Th e comprehensive commercial activities of ports and economic hubs were very well suited for the distribution of rats at various distances through the transportation of many types of goods, merchandise, and commodities over land or sea or along rivers by various types of vehicles or vessels or

111 See, for instance, Astill 1988: 51–2. 112 Davis 1986: 457–8. 113 Weber 1966, Lopez 1976, Pounds 1974.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 105 even pack horses.114 One could consider the implications of the IPRC’s observation: “We have seen rats dive, as it were, into bags containing bran and disappear, so that the bags could be moved without any evidence of the presence of the rats within. M. rattus [= Rattus rattus, the black rat] from its habits is particularly liable to be transported in this way […].”115 Davis’s central argument is based on the untenable notion that black rats could spread over land only by individual locomotion, by moving on their feet. According to ordinary scholarly methodological principles, Davis should be obliged to explain to his readers the empirical grounds which permit him to state that in medieval urban centres “A spread of up to a kilometre or so [by black rats] can nevertheless occur.” It is the basic fl aws of his theory that force him to found his arguments on such absurd notions as ports as islands suitable for the study of the functions of “the principles of island zoogeography.” In the end, he has to admit that “Factual support for these applications of island geography are regrettably meagre.”116 However, he proceeds unaff ected to go on arguing his theory as if this were not the case, which allows him to conclude triumphantly that he has proven that there could only have been an incidental presence of the black rat in the northerly parts of Europe, the concept of proven here being released from its strong evidentiary associations. Th is line of argument is supplemented by further arbitrary assertions to the eff ect that because “towns, the ships and the docks were small, we can assume that the rate of extinction was high” and that “persistence of populations of rats would have required frequent arrivals of ships from the Mediterranean, where rats were widely distributed.” In methodological parlance, the concept of “assumption” applies when there is an evidentiary basis that constitutes suffi cient ground for making an inference in relation to some part of reality, and this evidentiary basis is more demanding than in the case of other words implying lower levels of tenability such as “plausible” or “possible” or “hypothetical” or “speculative.” When the evidentiary basis is not presented, as in this case, the appropriate terms would be “speculate” or at best “hypothecate.” According to the principles of methodology, each

114 Pollitzer 1954: 294; Pollitzer and Meyer 1961: 452; Shrewsbury 1971: 29. 115 IPRC 1908b: 255. 116 Davis 1986: 458.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 106 chapter three of these assertions is a speculative working hypothesis that requires corroborative evidence in order to cross the dividing line between speculation or hypothesis and valid statement on reality at some level of tenability, however slight. Eventually, this point also occurs to Davis since he states that from “these principles we can construct a hypothetical history of rats in Europe.” However, he immediately leaves the methodological implication of this characteristic, concluding in terms requiring a signifi cant empirical basis: “Th e available evidence indicates that Rattus rattus was rare and erratically dispersed both geographically and temporally at the time of the Black Death.”117 However, no evidence to this eff ect has been presented. Th is unsubstantiated history is based on the speculative view that black rats could not uphold an autonomous widespread presence. Finds of rat bones force a small admission to the eff ect that black rats may in Roman times have been spread from the Mediterranean region by ship transport to ports in Western Europe in a continuous process that secured a small and continuous presence of the black rat in ports. According to Davis, the decline in shipping with the break down of the (Western) Roman Empire and the beginning of the Middle Ages meant that ports became so small that “it resulted in the extinction of rats in most cities of the north” and “the size of remaining ports were not adequate to maintain large rat populations.” Th is is plainly serial speculation that can provide premises for any hypothesis. It is also an expression of ignorance: there was no direct shipping between Mediterranean ports and Western Europe in Roman times and up to the end of the thirteenth century, rats would have a local origin and a continuous presence. It ignores also the widespread fi nds of rat bones from Roman times far from ports in many parts of Europe (see below). Davis goes on to argue that the “increase in shipping and the size of ports in Columbian times released an avalanche of rats which has been reduced only in recent decades.”118 Around 1500, the size of Europe’s population was close to the late medieval minimum aft er the ravages of the Black Death and subsequent plague epidemics. Th e intensity and volume of international trade, the size and ramifi cations of banks, and so on, were vastly greater around 1300 than around 1500, as were the size of populations and volume of general economic activity. Th is is the

117 Davis 1986: 468. 118 Davis 1986: 458–9.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 107 reason Lopez writes about the commercial revolution of the High Middle Ages, and I write about the plague history of the Late Middle Ages. If there was to have been an avalanche of imported rats into northwestern Europe, the High Middle Ages up to 1350 would have been the period of pre-eminence. Davis’s arguments are without basis in the economic and demographic history of the Middle Ages. Th is leads Davis to a peculiar conclusion: “Evidence for this chronology is meagre, but it off ers a plausible explanation of changes in rat populations.”119 Since he has not presented any empirical evidence in support of this chronology of rat history, and even characterizes it him- self as a “hypothetical history of rats in Europe,” it is not “meagre,” it is non-existent. Methodologically, this relates to the fact that the concept of “plausible” relates to a level of tenability which requires suffi cient evidence to position it between the level of possible and the level of likely. Davis appears unwilling to accept that what he really is doing is constructing an explanatory model on entirely speculative and hypothetical grounds. He also appears unable to accept the fact that a model is an intellectual tool that proves nothing, but which in the hands of a conscientious scholar can be useful for the collection, organization and analysis of empirical material. In addition, Davis’s knowledge of plague disease is unsatisfactory. It is not true that “most cases during the Black Death were of pneumonic plague” and that this “is now documented.”120 He refers for support to Biraben 1975: 86, where the opposite is maintained, namely that there could have been some episodes of primary pneumonic plague, but that “everywhere else it appears in the bubonic form with secondary pneumonic or haemorraghic manifestations.” In the immediate continua- tion of this statement, Biraben also makes it clear that these epidemics of bubonic plague which dominate the scene “are arrested or diminished by the cold season,”121 Davis is aware that primary pneumonic plague “occurs all year round,” he knows also that bubonic plague is “a disease [typically present: my insertion] in late summer,”122 and he has seen Biraben’s strong evidence to the eff ect that the Black Death was

119 Davis 1986: 459. 120 Davis 1986: 460–1. See Benedictow 2004: 27–31, 233–41. Davis does not diff er- entiate between primary and secondary pneumonic plague, but has apparently primary pneumonic plague in mind. 121 My translation from French. 122 Davis 1986: 460.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 108 chapter three bubonic plague, which does not accord with his assertion on the pre- dominance of primary pneumonic plague. Th is puts in perspective Davis’s assertion that “fall and winter epidemics were surely not the result of the transmission by fl eas from rats.”123 In the accompanying footnote he refers to (1) Gras 1939: 305, (2) Simpson 1905: 159, (3) Gasquet 1893: 43, and (4) Th e Indian Plague Research Commission 1907: 324–476. I will comment on these references below in paragraphs marked by corresponding number. First, it must be pointed out that he calls the IPRC the “Indian Advisory Com mission,” which refl ects his confusion of the scientists who made the research and wrote the papers or reports with “Th e Advisory Committee” which was responsible for controlling the quality of the papers and arranging for their publication. Lamb makes painstakingly clear the diff erence between the Advisory Committee and the Research Commission in his summary of their work up to May 1907: “It was arranged that reports of the work done by the Commission should be published by the Advisory Committee in the Journal of Hygiene.”124 Since it can be shown that Davis has not read the papers contained in these pages (see below, paragraph 4), this confusion may be taken to be a consequence of Davis’s hasty look at the title on the opening page of this sequence of papers in the Journal and its last page in order to produce a seemingly normal reference. Th is is not, as will be shown, the only case. (1) Gras’s paper is a study on the Black Death in the small Burgundian town of Givry on the basis of the only surviving complete parish register in Europe from the time of the epidemic. However, according to this study, the fi rst victim of the Black Death died 17 July, the epidemic slowed down sharply in October and petered out in the fi rst half of November, and in the second half of November three fi nal cases are registered on the 19th.125 Th is is not a case of a “fall and winter” epidemic, but instead in conforms to Biraben’s general account of the seasonality of the Black Death in France. Clearly, this reference is also fi ctitious. One should note that rat fl eas are typical fur fl eas (and not nest fl eas),126 which means that they spend much of their adult lives in the

123 Davis 1986: 467. 124 Lamb 1908: ii–iv. 125 Gras 1939: 305–6. 126 IPRC 1908b: 245–6, 258; Liston 1924: 997; Pollitzer 1953: 321; Pollitzer and Meyer 1961: 461; Busvine 1976: 37.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 109 fur of their hosts, enjoying there a relatively warm microclimate even in chilly or cold weather and ample feeding opportunities. Th is explains why plague epidemics can produce cases in chilly or cold autumnal weather, although at a rapidly diminishing rate, until the depletion of the number of rat fl eas and the reduction of septicaemia in plague- infected rats caused by cold weather stop the epidemic or it manifests itself by only occasional cases. Th e idea that plague epidemics must stop abruptly with the advent of chilly or cold weather is untenable.127 (2) Simpson 1905: 159, does not relate to the Black Death or the subsequent late medieval or early modern plague epidemics. Th is page is the fi rst in a chapter on “Variation in Virulence of Plague Epidemics” which has nothing to do with Davis’s subject. Consequently, this is also a fi ctitious reference. Evidently, Davis has again arbitrarily picked some pages in order to produce a false impression of a normal reference in a footnote. (3) Gasquet 1893: 43, relates to the Black Death in Avignon. Th e course of this epidemic cannot be followed closely, but the epidemic continued during the winter months. It is generally agreed, especially on the basis of the clinical descriptions of Guy de Chauliac, the pope’s personal physician, that this phase of the epidemic was predominantly primary pneumonic plague or rather a mixed epidemic.128 Since this is a unique case, as no other case of an epidemic of primary pneumonic plague or more likely a mixed epidemic is known, it does not at all support Davis’s assertion that the Black Death was at least predominantly primary pneumonic plague. Much has been written on the Black Death in Avignon aft er 1893. (4) Davis’s reference to IPRC 1907: 324–476, comprises not one but ten studies which all have in common that they do not relate to the subject in question and do not, consequently, contain support for his assertion which therefore is arbitrary. On the same page, Davis asserts that “Human plague can occur without involvement of Rattus. For example in India only eight of forty local epidemics had obvious mortality of Rattus.” In the accompanying footnote, Davis provides three references to scholarly works in support of his assertion, all of which need close and sceptical scrutiny: (1) Hirst 1953: 121; (2) Martin 1913: 63; and (3) Hirsch 1883, Vol.1: 494–544. I now comment on each of these references:

127 See below: 396–8. 128 Benedictow 2004: 97–8, 236–8.

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(1) Hirst 1953, 121: Hirst’s monograph is devoted to the study of the history of human combat of bubonic plague. He does this in a broad and in-depth historical perspective of the development of medicine and epidemiology and concludes with a strong case for the rat-fl ea theory of bubonic plague. Every scholar who has read this outstanding standard work on bubonic plague will immediately recognize that Davis’s reference is fi ctitious. Far from providing support for Davis’s assertion, Hirst argues strongly against it. On page 121, which is sited by Davis, starts Chapter VI on the role of “Rats and Plague”; the subchapter starting on this page relates to “Rats and the First Two Pandemics.” Th us, this chapter does not relate to the third pandemic and developments in India in this period. On page 121, Hirst begins by emphasizing very strongly the early resistance among scholars to the rat-based rat-fl ea theory of bubonic plague. (2) It is on the following page, Hirst 1953: 122, that Davis had the luck to fi nd his next reference, namely Martin 1913: 63. Here Hirst states that “the paucity of records directly and clearly associating human plague with mortality among rats in medieval literature has led some authorities, including Sir Charles Martin and Professor Jorge, to postu- late the human fl ea as the chief transmitter of the bubonic element of the Black Death.” Th is view asserts the importance of interhuman spread of plague which begins from rat plague but then continues independently of rats by cross-infection, a view with which Hirst entirely disagrees and against which he argues intensively over many pages. Davis has, thus, made a misleading reference to Hirst’s monograph in support of his own view. He makes no reference to Hirst’s comprehensive discussion leading to his conclusion on the fundamental role of rats and rat fl eas in the epidemiology of bubonic plague among human beings, including in India. A huge number of studies have appeared aft er Martin published his study in 1913, among them quite a number relating to the possible role of the human fl ea, and they aff ect the tenability of Martin’s opinion. Many of these studies are used and referred to by Hirst. Certainly Hirst disagrees, this is at the heart of his monograph: the role of fl eas is discussed in the following chapter, the question of interhuman spread in Chapter IX, and the spatio-temporal patterns of plague epidemics in Part III, Chapters X-XII. In fact, even the most ardent supporters of the human-fl ea theory, namely G. Blanc and M. Baltazard, do not maintain that the Black Death or subsequent plague epidemics were in the main spread by the human fl ea, only that it could be of importance in the great cities of the Middle Ages, which

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 111 means that at most 2 per cent of Europe’s population would be at risk, and the hypothesis of little consequence even if it were tenable.129 Th e main reason that the human-fl ea theory is untenable is that plague sep- sis in human beings is generally far too weak to infect fl eas suffi ciently for development of blockage other than in sporadic cases.130 (3) Davis’s third and last reference in support of his view on this point raises immediate scepticism, namely that to August Hirsch’s two- volume Handbook of Geographical and Historical Pathology of 1883, which is an English translation of the two-volume German edition of 1860–4. Th is work is surely much too old to contain scientifi cally tenable information on the matter. I have taken a look at the original German edition and also the second edition of 1881–6 (three vol- umes) which are the versions owned by the University Library of Oslo. In the fi rst edition, bubonic plague is presented in Volume 1, in a chapter of twenty-three pages, which fi ts very poorly with the fi ft y pages to which Davis refers. Th is chapter does not contain anything to the eff ect that involvement of rats was observed in only eight of forty plague epidemics in India. Since the presentation of plague in the original fi rst edition starts on page 192, it may seem quite impossible that this chapter in the English translation should start on page 494, at which point the original German edition is in the middle of a 312-page discussion of chronic diseases. One could also take into account that the properties of the English language make translations from German shorter, not longer.131 Hirsch’s work is, of course, unscientifi c, based on the theory of miasma in both editions, and it contains no reference to bubonic plague later than 1850.132 Th is makes it clear that the author could not consider any theory of bubonic plague involving bacteria, rats and rat fl eas as agents, carriers and transmitters of bubonic plague among human beings. Hirsch has of course not had the opportunity to learn from and take into account the modern scientifi c studies performed by Ashburton Th ompson, the IPRC or van Loghem and Swellengrebel who discuss the behavioural patterns of rats and revealed that epizootics among rats were, in fact, at the basis of epidemics of bubonic plague.

129 Benedictow 1993/1996: 228–37. Cf. Benedictow 2004: 17, fn. 9. 130 Benedictow 1993/1996: 243–63. 131 In the much expanded second edition, the chapter on bubonic plague runs from page 349 to page 384. 132 Hirsch 1860: 211. Th e chapter on bubonic plague in the second edition of 1881 contains a few later references to plague epidemics, but not in India.

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Davis’s reference to Hirsch is fi ctitious; Hirsch’s book cannot be the source of his assertion that only eight of forty plague epidemics in India exhibited evidence of involvement by rats. Th e real basis for Davis’s assertion is taken from Hankin’s paper of 1905. Here Hankin summarises a report by Planck relating to the Garhwali area where plague tends to be “endemic” in the Annual Report of the Sanitary Commissioner for the North-West Provinces and Oudh for the year 1876.133 While Davis presents his assertion as if it were based on scientifi cally tenable research, for instance Hirst’s monograph, it can now be seen that the basis is another proto-scientifi c report written many years before the establishment of bacteriology and therefore also based on the miasmatic theory of epidemic disease and without notions of any role for rats or insects. On the basis of relevant scholarly studies, the question of why rat falls are such rare sights during plague epidemics has been quite extensively discussed above. Th is makes it clear that Davis’s assertion could not be based on valid evidence. Importantly, Hankin uses the term “endemic,” which means sporadic cases, so that in this context the term “outbreak” does not refer to epidemic plague and a large number cases. Th is means that the role of rats would not be obvious because of the sporadic and endemic incidence of the plague cases, in addition to the other factors cited above. Th e report Davis refers to is not relevant for the understanding of epidemic plague. Davis asserts in seriousness that the human fl ea might have been involved in the dissemination of plague, because they “can transmit the bacillus that appears in saliva and human feces.”134 Human fl eas like other types of fl eas are ectoparasites, bloodsucking insects, and do not ingest human saliva both because they do not have access to it, and because it would not be useful as nourishment or as a necessary basis for the production of eggs which unconditionally requires blood. Certainly, human fl eas are not dung insects and will not touch human faeces with their proboscises. Davis asserts also that “Buboes can occur in cases of pneumonic transmission and cannot be construed as proof of transmission by fl eas that infest either rats or humans.”135 In support of this statement, he

133 Hankin 1905: 49–50, 66. 134 Davis 1986: 461. 135 Davis 1986: 461.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 113 refers to the following standard works on plague, namely Wu Lien-Teh 1936b: 409, Hirst 1953: 29, Pollitzer and Li 1943: 161/212–6136 none of which works contains anything that supports his assertion, neither on the indicated pages nor elsewhere. Th ey are fi ctitious references.137 Wu Lien-Teh’s standard work on primary pneumonic plague makes it clear that the pneumonic mode of infection does not give rise to buboes.138 Davis goes on to present other misleading statements on plague. He asserts, for instance, that the Black Death “travelled across or around the Alps in the winter.”139 Th is is not correct, the Black Death’s advance into the Alpine area stopped with the advent of cold autumn weather which extinguished its epidemic manifestations, and it did not re-emerge until the advent of spring temperatures when it started pen- etrating into Southern Germany. Its spread in this region was also temperature-dependent, requiring temperatures of the warmer seasons, which can be easily explained by a rat-based and fl ea-transmitted disease.140 Davis asserts also that in “Europe the spread of plague was rapid,” its “speed and intensity was remarkable” and incompatible with spread rates characteristic of contiguous spread between rat colonies. His empirical examples of rapid spread of the disease are that it travelled to: (1) Paris in six months, and to (2) southwestern England by December; it spread to (3) northern Norway (Bergen and Trondheim) in a year; (4) it permeated all of England within months.141 Th e enumeration is mine, and my comments below are marked by corresponding numbers. Davis does not mention the point in time of the start of epidemic spread from the chosen point of origin and the time of its arrival at the chosen destinations. Neither does he clarify his con- cepts of speed or rapidity by providing his readers with his criteria and explaining why he considers these characterizations suitable. As will be

136 Th e discrepancy in the page numbers is due to my use of the version published in Chinese Medical Journal 1943: 212–6, while Davis refers to a somewhat shorter version published at the same time in Journal of Infectious Diseases 1943: 160–2. 137 Neither does Wu Lien-Teh mention such cases in his monograph on pneumonic plague. Wu Lien-Teh 1926: 241–73. 138 Wu Lien-Teh 1926: 184–7. 139 Davis 1986: 460. 140 Benedictow 2004: 186–90. 141 Davis 1986: 460–1.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 114 chapter three seen, they are not only arbitrary in form but also erroneous and confused in fact. (1) Th e fi rst outbreak in France was noted in Marseilles 1 November 1347, and the outbreak in Paris was noted at the end of August, which means that ten months passed between the arrival of the Black Death in France and its arrival in Paris. However, the part of the Black Death that spread northwards from the original epicentre at Marseilles killed its fi rst victim in Givry in Burgundy on 17 July (according to the parish register), which means that in mid-July the epidemic was more than 300 km from Paris as the crow fl ies, and much further by ground transport. It also means that by the end of August it would have moved only about 60–70 km further on its way northwards and still be several hundred km away along the main roads to Paris.142 Th e crucial point that Davis has missed is that the Black Death was shipped out of Bordeaux to Rouen in Normandy in time to cause a recognized outbreak there in June and could cover the much shorter distance thence to Paris in time for an outbreak at the end of August, a spread rate that would quite likely have been hastened by ship transportation up the R. Seine.143 Th e basic problem here is that Davis does not recognize the importance of metastatic leaps which will be comprehensively discussed below in the next main chapter. (2) Davis’s assertion that it is an example of remarkable speed of spread that the Black Death could spread from Melcombe Regis (Weymouth in southern England), where it broke out shortly before 24 June 1348, to southwestern England by December is intriguing, since the Black Death started in southwestern England. It has long been known that by the beginning of August most of the tenants of Frome Braunch in Somerset had died and that peasants had died on other manors in the area. It has also been long known that the Black Death broke out in Bristol on 15 August, shortly aft erwards in Gloucester (and that it had broken out in coastal towns of the Pale in Ireland by early August).144 Th e reason Davis again is so out of line with historical plague research and reality here is that he does not recognize the crucial importance of metastatic leaps in plague epidemiology and he has poor knowledge of the relevant historical studies.

142 For spread rates in this part of France, see Benedictow 2004: 106, 230. 143 Benedictow 2004: 72–3, 96–108. 144 Benedictow 2004: 126–8, 130–1, 143–4.

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(3) As a Norwegian scholar who has specialized on plague history and who has written his doctoral thesis on the late medieval plague epidemics in the Nordic countries and a complete history of plague epidemics in Norway (1348–1654),145 I do not understand what Davis means when he states that the Black Death spread to “northern Norway (Bergen and Trondheim) in a year” and one should take into account that Norway is a very long country, over 2000 km long. Bergen is situated on the western coast of southern Norway and is only slightly more northerly than Oslo, while Trondheim (Nidaros at the time) is situated in central Norway. In short, these two cities are not situated in northern Norway, literally far from it. Th ere are no sources on the history of the Black Death in northern Norway or even north of Trondheim/ Nidaros; all medieval Norwegian sources have been published and I believe that I have identifi ed every source that could have a bearing on the history of the Black Death in Norway. Th e history of the Black Death in central Norway north of Trondheim and in northern Norway is unknown and may remain so, although the new scholarly discipline of paleomicrobiology holds out promise of microbiological identifi cation of Yersinia pestis in archaeologically datable plague graves.146 Obviously, this part of Davis’s statement refl ects great historical and geographical confusion or disorientation, and what Davis has in mind may therefore just be confused and disoriented. Th e only possible realistic interpretation I can make is that the Black Death spread to Bergen and Trondheim in a year, taking into account these cities’ correct geographical position. In this case, the facts on the ground are that the Black Death was introduced to Bergen directly from England, probably by a ship transporting grain from King’s Lynn; the disease broke out in Bergen some time in the second half of August 1349, and was transported by ship thence to Trondheim where the outbreak appears to have been in full development at the end of September. At the time, the usual duration of a voyage from Bergen to Trondheim (or vice versa) was a fortnight.147 Obviously, these developments cannot support an argument that the Black Death spread so rapidly that it could not have been bubonic plague. Th ere is nothing in the pattern of spread which is at variance with the normal assumptions of the spread rates of

145 For the history of the Black Death in Norway see Benedictow 1993/1996: 73–102; Benedictow 2002: 46–96; Benedictow 2004: 146–58; Benedictow 2006: 83–163. 146 See below: chapter 11: 249–58. 147 Benedictow 2002: 67–80; Benedictow 2004: 102, fn. 20.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 116 chapter three bubonic plague if the erroneous assertion that bubonic plague spreads only between contiguous rat colonies is discarded and we take into account metastatic spread over long(ish) distances by ship and by land and over short and intermediate distances by the agency of human beings transporting rat fl eas in clothing, luggage, or goods (see below). Th e average daily spread rate along the main roads was about 1.25–1.5 km.148 (4) It would have been a proof of remarkable speed of spread if it were true that the Black Death “permeated all of England within months,” actually it would have been a remarkable feat for any conta- gious disease whatever its mechanisms of dissemination and transmission, especially under medieval conditions of communication and transportation. However, this assertion is without basis in research. Th e Black Death broke out in Melcombe Regis shortly before 24 June 1348 and petered out in northern England in the late autumn of 1349.149

Th e Signifi cance of Evolutionary Th eory and Adaptation by Selection

Despite the agreement among advocates of alternative theories of plague that black rats are too warmth-needing to establish more than a sparse and transient presence in the northerly parts of Europe, it has been easy to demonstrate that this view has been argued in ways that makes it untenable on source-critical and methodological grounds. Th e lack or paucity of references to dead rats in contemporary accounts of plague epidemics does not support the assertion that there were no dead rats; instead this inference is a fallacy of methodology. Th is makes it clear that the argument that black rats are too warmth-needing to have a signifi cant presence in the northerly parts of Europe has a principally explanatory character. Th is explanatory function can only be relevant and activated when it has been empirically proved that rats were, in fact, absent or few and far between in these parts of Europe and such an observation needs explanation. Consequently, it is also a fallacy of methodology to use this explanatory potential as factual evidence to prove the absence or approximate absence of rats, as all these advocates of alternative theories do. Instead, the methodological status

148 Benedictow 2002: 35–40, 319–20; Benedictow 2004: 151–3, 157–8; Benedictow 2006: 91–5, 107–8, 113. 149 Benedictow 2004: 126–31, 138–42.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 117 of this notion is that of a working hypothesis that must be corroborated by evidence in order to assume the character of valid assertion with some level of tenability. It has also become clear that this argument is methodologically problematic in yet another respect: the plague epidemics of the past could in principle provide the basis for a hypothesis that they represent a refl ection of a broad presence of black rats and, consequently, that the epidemics were bubonic plague. Th ese two legitimate hypotheses are diametrical opposites, a fact which demonstrates that up to this point in the discussion nothing has been precluded: it is universally agreed that there must have been at least a tiny sprinkling of rats, not necessarily enough to generate epidemics of bubonic plague. Th e crucial question is how these two hypotheses can be empirically tested. Twigg and Davis and other advocates of alternative theories assert that in the Middle Ages there could only have been autonomous or self-maintaining small rat colonies in Mediterranean ports, and possibly also in some rural districts. In the ports of northwestern Europe there were no rats or only a tiny and transient population of rats which could not reproductively maintain itself and establish itself there per- manently, and their presence was dependent on a trickle of new rats by ship from Mediterranean ports. As pointed out above, regular direct voyages between Mediterranean ports and northwestern Europe did not begin until quite late in the thirteenth century. On logical grounds alone there could not have been any rats in these parts of Europe before that time if the assumptions of the advocates of alternative theories were tenable. Instead, the implication is that there was a continuous presence of rats. It has been shown above that negative assertions in this respect are not empirically based but are speculative notions or working hypotheses awaiting corroboration. In this connection, another methodological point should now be mentioned, namely that the methodological requirements for proving that some phenomenon did not exist or taken place tend to be rather more demanding than for adducing positive proof of a phenomenon or event. Th e argument asserted by advocates of alternative theories that since the black rat originated in a warm region means this species is too warmth-needing to have a signifi cant and continuous self-maintaining presence in the northerly parts of Europe is based on a very narrow view of the question: it neglects to consider the possible signifi cance of evolutionary theory and the process of adaptation and development of

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 118 chapter three species by natural selection. In the words of Pollitzer, rats are “extremely fertile.” Th ey reach sexual maturity long before they have completed their growth, when they are about three months old. Th e females have a sexual season extending for about nine months of the year, during which they are “in heat” at intervals of about ten days, the period of gestation is about twenty days, parturition tends to be immediately followed by “heat” so that a female can be impregnated a few hours aft er the birth of a litter. Th is means that there are many litters during a year and the number of young per litter is, on average, 5.4–6.150 Th e mortality rate of sucklings is quite high, but this also means that the forces of evolutionary selection are intensely at work, making for relatively rapid adaptation to changing circumstances.151 Th e view that a species with such enormous fertility and brief generational cycle as the black rat should not be able to adapt to various biotypes, ecological niches, and climates, is obviously untenable. Clearly the advocates of alternative theories accepted this hypothesis without careful consideration simply because it agreed with their theories. Th e heart of the matter can easily be put in perspective. Th e Vikings brought horses to the Shetlands and to Iceland when they began to settle there at the end of the eighth century and in the 860s ad respectively.152 Within a few hundred years, these horses developed into the Shetland pony and the Iceland pony characterized by considerably reduced size, a rough coat, and a long mane and tail as evolutionary adaptations to the new environments. Th us, new, smaller and hardier breeds of horses had come into being in these islands as early as the High Middle Ages. When horses with only a tiny fraction of the fertility of rats and much longer generational cycles can adapt so readily to new and diffi cult climatic and ecological circumstances, the complete rejection by all advocates of alternative theories of plague of the possibility that rats could have any such adaptability becomes the more remarkable. Can it really be true that rats arriving in the northerly parts of Europe would not develop by the process of evolutionary selection into a hardier breed with size and coat adapted to the climate? Does not such a surprising assertion demand a specifi c and empirically based

150 IPRC found an average of six foetuses in 975 pregnant rats in the Punjab, IPRC 1907j: 907, and 5.4 in 4841 pregnant rats in Belgaum in Bombay Presidency. IPRC 1910c: 457. See also Liston 1924: 998. 151 Pollitzer 1954: 290–1. Cf. IPRC 1907 g: 750. 152 Lamb 1995: 173–4; Sawyer 2003: 106, 112.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 119 defense? Do not the bare assertions that this is excluded or improbable in the case of rats and the complete absence of empirical arguments to this eff ect represent a fallacy of methodology? Would it not be logical to consider adaptation by degrees, as black rats were transported northwards in Europe over the centuries, which would introduce a long-term evolutionary perspective? M. McCormick emphasizes that to assume that “only human support can sustain rat populations outside a Mediterranean ecology is to underestimate rats’ adaptability.” He underlines this point by referring to the fact that burrowing black rats are found thriving in subantarctic conditions on Macquarie Island, latitude 54.30° S, longtitude 159° E, not far from Antarctica. Black rats are also living in the chilly and windy north Atlantic climate of the Shiant Islands in the Hebrides (Scotland). Interestingly, the zoologists who studied these black rats in the Shiant Islands, in stark contrast to Davis and Twigg, state fi rmly and unconditionally that “Rattus rattus was once widespread throughout the UK.”153 Th e black rat was also present until recently on Lundy Island off the northwestern coast of Devon,154 having survived from the Middle Ages in the absence of the brown rat. Size is important for the survival or improvement of the competitive situation of rats (as for other animals). According to the same evolutionary reasoning, McCormick emphasizes that “the size of modern black rats might be a misleading criterion, since substantially larger ones are documented in medieval Corsica.”155 Th is is also the case with fi nds of medieval rat bones both in England, Norway and Sweden (see below). Correspondingly fl eas which have much higher fertility and shorter generational cycles than rats, would readily adapt by selection—fl eas might, in the words of Bacot, “adjust itself to the varying conditions of climate experienced in its geographical distribution.”156 Th is is also underlined by Pollitzer: As shown by its wide geographical distribution, X. cheopis is able to adapt itself to a considerable range of climatic conditions. It is, as have been

153 McCormick 1998: 22–3; Key, Fielding, Goulding et al. 1998: 228–33. Under ordinary circumstances, I would have tended to think that these studies would have been of interest to Icelandic scholars. 154 James 2001: 12, and pers. comm. Th ese rats have subsequently been exterminated. 155 McCormick 2003: 3. 156 Bacot 1914: 449–50.

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previously noted, the common rat-fl ea in Manchuria and is also the prevalent species in the tropical section of Brazil.157 Another error at the heart of the arguments of Davis and Twigg is that they project anachronistically into the Middle Ages the modern situation of black rats. In modern Western society, black rats arriving in the northerly parts of Europe or North America by modern means of transportation directly from warm countries are not only poorly adapted to the new environments; further, their situation with respect to having the opportunity of going through a process of evolutionary adaptation is very diff erent from what it was in historical European societies, for three important reasons: (1) they are mercilessly fought by the larger and more aggressive brown rat which did not arrive in Europe before the eighteenth century; (2) modern buildings and settlement structures are poorly suited for the establishment of colonies of house rats; (3) modern man has a very hostile attitude towards rats in their habitations. Th ese three factors cause too high mortality rates among these rats to allow adaptation by selection before they are exterminated. In these circumstances, their presence will be dependent on fresh arrivals by ship, according to the model constructed by Davis and Twigg, but applied anachronistically by them to the Middle Ages. Rats have a rich and complex history which is structured according to a number of evolutionary developments and a plethora of social, economic and cultural factors in the human societies on which they depend. To project the situation of black rats in modern Western society back into the Middle Ages is obviously fallacious. Th e inherent dangers in neglecting to address the theory of evolu- tion by natural selection for a species can also be demonstrated in relation to rats in several ways with profound theoretical and empirical implications. It has been shown, for instance, that black rats in the northerly parts of Europe could have had several diff erent origins. Since both Twigg and Davis refer to Hirst’s monograph of 1953, it may be instructive to cite his statement that “the fossil remains of a very similar species [to black rats: my insertion] have been found near

157 Pollitzer 1954: 327.

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Geneva, in Lombardy, Bohemia, and Crete in Pleistocene strata, and numerous bones among the pile dwellings of Mecklenburg.”158 Th us, several fi nds of fossils of animals very similar to the black rat have been made from a pre-historical period starting more than a million years ago and stretching to about 10,000 years ago, covering several very cold periods or ice ages. Th is suggests that the black rat or rather a closely related species may have been present continuously in Europe, retreat- ing with expanding glaciers and following in the wake of their with- drawal much like reindeer, bears, wolves and many smaller mammals. Th is notion is supported also by the fact that numerous bones of this rat or a similar rat have been found in excavations of human settlements in northeastern Germany from about 4000 to 2500 years ago. Th is can be taken to indicate the continuity of a species of rat very or at least quite similar to the black rat which was well adapted to life in northerly climatic zones. It also suggests that this rat rapidly found a new and attractive environment or ecosystem with the advent of human beings and their housing, settlements and economic activities, especially farming and animal husbandry with their corresponding products and outbuildings. As pointed out by Hirst, this indicates that “rats were associated with man since his fi rst cultural beginnings, since the time when he fi rst began to store large quantities of cereals in grana- ries.” Since this provides evidence of a species of rat which is quite closely related to but not identical with the black rat, it may usefully be taken as evidence of the black rat’s adaptability by evolutionary selection to northerly climates and environments, and evidence that black rats have adapted to northerly climate at least once, and quite likely twice in the past. Th e material is too small to constitute proof of the continuous presence of this species of rat from the Pleistocene or the Bronze Age to the Middle Ages, or of its early and continuous association with man. However, this evidence may serve as the basis for a well- founded working hypothesis calling for further investigation. Davis and Twigg would have been right in their view that the black rat and its accompanying fl eas would quite likely not have survived in the northerly parts of Europe if specimens were picked up in India and dropped there by parachute. However, if a long time perspective and conditions for adaptation are introduced in an evolutionary model which lets rats and their accompanying fl eas start from southern

158 Hirst 1953: 126. Davis 1986, refers erroneously to page 121.

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Europe and gradually spread northwards over centuries, both black rats and their fl eas would easily produce variants or biovars adapted to the new conditions. It is therefore a fallacy of methodology and evolutionary theory to assume, without empirical evidence, that black rats of modern India and black rats in the northerly parts of Europe in the Middle Ages or Early Modern Period were biologically identical in the sense of having the same biological adaptation to environments, biotopes and climates. Th is is a valid argument also for a comparison of black rats in southern Europe and northern Europe at the time. Th is perspective will now be tested against the sources and material evidence. Th e presence of rats in Europe at the time of the Black Death is the focus here. In consideration of the large time spans in question, we must take into account the possibility that there may have been another later independent introduction of the black rat, representing a second or third introduction, and another subsequent evolutionary process of adaptation. If it were correct that it was too cold in the northerly parts of Europe to allow a broad presence of black rats and that nonetheless the same disease ravaged this part of Europe as southern Europe, this would constitute independent and suffi cient proof that the Black Death must have been some disease other than bubonic plague. Consequently, evidence on the presence of rats in Europe, especially the northerly parts of Europe in the preceding centuries, would be of pivotal importance.

Rat Bones: Material Evidence of the Presence of Rats in the Middle Ages

In Europe, rat bones older than ca. 300 years must be remains of the black rat. Twigg argues that it is reasonable to dismiss the signifi cance even of archaeological fi nds of rat bones in medieval layers on the grounds that the “Black rat in temperate latitudes today lives only in the warmer parts of towns and it is likely that it has always done so” and adds that “Rattus rattus is essentially a sedentary animal, therefore in temperate climates its occurrence in towns where it does not leave the warmth of buildings is a fact of great signifi cance in the aetiology of bubonic plague and one we should remember when viewing past epidemics of that disease.”159 As shown above, this type of argument is

159 Twigg 1984: 80, 88.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 123 fallacious. It represents an attempt to make an argument which is at variance with the elementary methodological principle that all scientifi c and scholarly arguments must in principle be open to falsifi cation. Twigg also attempts to undermine the signifi cance of ndsfi of rat bones in layers of medieval remains on the basis of two other premises, namely that (1) the brown rat is known for its prowess in burrowing, and (2) the bones of the black rat and the brown rat are quite similar and their remains are therefore oft en diffi cult to separate. For this reason, he holds that fi nds of rat bones in archaeological excavations of medieval sites do not constitute evidence of the medieval presence of the black rat, but could refl ect the burrowing capacity of the brown rat.160 However, Twigg does not take into account any limit to the depth to which brown rats were apt to burrow. It is therefore important to emphasize that brown rats’ “burrows for shelter and nesting rarely exceed 18 inches (approximately 45 cm in depth),” and that they will only dig deeper in order to “gain access to food-supplies.”161 Since there is not much food to be found in medieval strata even for rats, burrows of the brown rat will normally be signifi cantly shallower than 45 cm, and will, consequently, oft en or normally not reach medieval layers that will tend to be deeper, especially in urban and village environments where deposits from daily life tend to increase the ground level. Another point is that rat burrows tend to be archaeologically traceable and their origin identifi able.162 For this reason, fi nds of rat bones in medieval layers will normally be remains of black rats and only exceptionally come from a brown rat, and then under circumstances where this will tend to be recognizable. Th e brown rat is normally larger than the black rat, also the size of the bones provides some useful if not deci- sive indication of the type of rat. While it is true that the burrows of brown rats may occasionally have penetrated into medieval layers, and that this should be taken into account, fi nds of the remains of rats in medieval layers are now so numerous that the great majority of them must be of the black rats. Diff erent types of evidence and arguments can be accumulated to produce a solid case for identifying rat bones found in excavations of Roman or medieval sites as medieval remains of the black rat.

160 Twigg 1984: 78, 80. 161 Pollitzer 1954: 286; he cites US Public Health Service, Communicable Disease Center (1949). 162 Rackham 1979: 112–20.

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Th e main conditions of source-criticism and the signifi cance of ndsfi of rat bones must also be assessed in a historical perspective. Zoo- osteological studies of fi nds in archaeological excavations are recent features of archaeological work, having been taken up beginning in the 1970s; this is especially the case with small bones. Earlier studies of small bones are so few that they can be considered exceptional, for instance, fi nds of two-thousand-year-old rat bones in Pompeii.163 Th is also means that while excavations up to about 1970, and to a large extent also later, have undoubtedly made signifi cant contributions to our knowledge of the past, they have also destroyed much valuable evidence for the study of bones, insects, and plants, and so on, which could help to form a more complete picture of human environments and ecology in the past. Much of medieval Oslo was destroyed when the fi rst railway was built in the early 1850s and also in the subsequent decades as the railway network was expanded; as late as around 1970, excavations of some remaining medieval sites were performed without sieving for small bones (such as rat bones).164 Wars have also been destructive, especially the mass aerial bombardments and massive use of artillery along the front lines and in urban battles which are characteristic of the Second World War. Archaeological excavations tend also to be performed in urban centres or at the manors and castles of the rich and mighty, whilst peasant houses and settlements have attracted much less interest and are oft en much less amenable to such studies. Black rats are nimble climbers and like to nest in the roofs or ceilings of human housing where they are safer from predators like cats, and also because warm air rises from the hearth and produces better living conditions there. Th is means that their bones and their nests will oft en be long gone or be dispersed in a way that will make fi nds very unlikely. Black rats are also, as mentioned, burrowing animals, and they have been burrowing away from human habitation also in the Nordic countries (see below). Th ey could have burrowed within medieval and early modern houses with beaten earthen fl oors until it became usual to build houses with timbered fl oors as in the Nordic countries or with tiled fl oors as in the more southerly parts of Europe, and subsequently and gradually also on low stone foundation walls, a process that appears

163 MacArthur 1952: 209. 164 Lie 1988: 159. I thank Professsor Egil Mikkelsen, Director of the Historical Museum, University of Oslo, for useful comments on this point in a personal communication by e-mail 25 January 2010.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 125 to have started in many places some time in the sixteenth century and to have been largely completed by 1800. Th is meant that the black rats increasingly had to focus on nesting in roofs or ceilings, outbuildings and burrows which increased their vulnerability, especially aft er the arrival and growth of the brown rat populations.165 One should note that it was usual in the past that live-in farm workers slept in the outbuildings, especially in stables and cowhouses where the dense housing of large animals produced a signifi cantly higher temperature which also would be attractive to rats, as would the opportunities for fi nding food. Unfortunately, in the large regions of the Nordic countries characterized by detached or semi-detached peasant holdings, houses have over many centuries and even millennia been reconstructed or replaced on the same or partially overlapping sites (toft s). In the villages of manors, especially in medieval Denmark, the lords in the process of so- called equalization organized the holdings into units of equal size more or less unhindered by customary rights typical of, for instance, contemporary English manorial economy. Th is makes it unlikely that medieval rat burrows will be found in such sites, or that such fi nds will be exceedingly rare. Th e fi elds from the Viking Period and the Middle Ages are also largely long gone, having been reworked many times and in recent gen- erations by heavy machinery which crushes burrows in the ground or works so deep into the soil that burrows will be destroyed. And of course archaeologists rarely study undisturbed fi elds of the Viking Period or the Middle Ages, so rat burrows in the fi elds near human habitation will remain undiscovered. Another factor is that undisturbed fi elds or toft s over such a long time will tend to be unrepresenta- tive for some of the same reasons that have made them unattractive for re-settlement. For all of these reasons, the chances of fi nding medieval rat bones or rat burrows may appear small, but such fi nds would be more likely in urban centres than in the countryside for reasons that may not have anything to do with the territorial distribution of black rats in the past. Consequently, the incidence and number of archaeological fi nds of rat bones should be expected to be small, but will increase as archaeologists more oft en look for small bones of animals and take a more complete interest in human environments of the past.

165 Benedictow 2002: 250, 276–8.

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Th e substantial number of fi nds of rat bones from the Middle Ages that is now available for analysis and their wide distribution across Europe is therefore a surprising result of archaeological investigations in this regard. Th e source-critical problem of the representativeness of archaeological fi nds of rat bones can also be illustrated in another way on the basis of the report that B. Hårding, the former Swedish osteologist, produced on the study of bone material found in excavations of the original area of the small town of Sigtuna (north-west of present-day Stockholm) which developed beginning in about 975 a.d. An area of about 1,100 m2 was excavated, bone material was collected from about 400 m2, but small bones from small mammals were only searched for with adequate methods in a sample of eight squares of 2×2 m, a miniscule fraction of the excavation area. Since the osteologist nonetheless found twenty- two rat bones of which fi ft een could be identifi ed with certainty as black rat,166 it would be inadequate to conclude that these bones represented just a few rats; instead it would be more realistic to infer that black rats were ordinary animals in the small town at the time, in the late Viking Period and the early High Middle Ages. As new archaeological fi nds of rat bones were steadily reported over the last decades, patterns of development and spread became observable. I produced the fi rst preliminary overview of fi nds up to 1991 in the medieval Nordic countries and northern Europe in my doctoral thesis.167 Th e rstfi full inventory of fi nds was published by F. Audoin- Rouzeau and F.-J. Vigne in 1994.168 Aft er this date, more than thirty new fi nds from about twenty ancient and medieval sites169 have been recorded and presented in a broad historical perspective by M. McCormick in 2003,170 a paper that appeared when my typescript on the history of the Black Death was with the publishers. However, in my monograph I give a broad account of such fi nds in the chapter “Rat History.” McCormick and I independently reached the same crucial conclusions about this material, although I have chosen to ignore the

166 Hårding 1992: 0–1 (sic), 4, 27. 167 Benedictow 1993/1996: 157–60. Th e writing of the dissertation was nishedfi in 1991, it was defended in 1992 and was published in a slightly revised form in 1993 and reprinted in 1996. 168 Audoin-Rouzeau and Vigne 1994: 125–45. Cf. Aduoin-Rouzeau 1999: 220–6. 169 McCormick 2003: 6, fn. 7. 170 McCormick 2003: 1–25.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 127 question of geographical origin of the black rat as being peripheral to my subject. A useful point of departure is the numerous fi nds of rat bones in Roman imperial territories in the West and also in its northern territories. McCormick summarizes fi nds of rat bones in sixty-fi ve sites from the Roman period up to the eighth century. Several fi nds of the skeletal remains of black rats dating back to Roman times have been found in Italy, they are widespread in Roman Gallia/Gaul (France), have been found near Amsterdam and in Valkenburg in the Netherlands, in southern Belgium, in Roman Austria and are widespread in Roman Germania all the way to about the city of Cologne (a Roman military camp called Colonia = settlement) in the northwest.171 In Switzerland, skeletal remains of two black rats have been found in excavations of a Roman villa near the city of Bern, the remains of one rat in the Roman town Augusta Raurica, present-day Augst, and the remains of a rat dating to the 4th–8th century have been found near Geneva.172 Many of these fi nds come from rural inland regions, and only a few from ports. In England, several fi nds have been made of the skeletal remains of the black rat dating back to the time of the Roman occupation, namely in York and London, at a Roman settlement (Gorhambury) near St Albans roughly 35 km north of London, in Wroxeter (Shropshire), and of two rats from the fi rst century a.d. in a Roman villa in Beddingham situated inland in East Sussex. Remains of three rats found in Walton, Aylesbury, in Buckinghamshire, the very heartland of rural England, have been dated to the 5th–7th centuries, and may therefore be from the late Roman period or transitional early Anglo- Saxon England; subsequent fi nds at this location up to the 9th–12th centuries refl ect a presumably continuous presence. Th ese finds are widely distributed in the northeast, southeast, central and western parts of England, respectively. Th ey are certainly not restricted to ports or to cities, which are the case only with the fi nds in London and York. Th e devastating implications of these fi ndings for advocates of alternative plague theories are demonstrated by the complete silence on these fi nds by Scott and Duncan in their monographs of 2001 and 2004. Th is permits them to maintain that “the black rat had not spread to northern Europe by the time of the plague of Justinian [540–1]” and

171 Armitage, West and Steedman 1984: 379; Audoin-Rouzeau and Vigne 1994: 129; McCormick 2003: 6, fn. 7. 172 Stampfl i 1965–6: 454–5; Audoin-Rouzeau and Vigne 1994: 129, 134–5.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 128 chapter three that the black rat may have arrived in England in the Middle Ages, but “a variety of dates have been suggested.”173 In support of these assertions they refer to Matheson’s book of 1939 and Shrewsbury’s monograph of 1971, again seeking refuge in obsolete works in relation to an important point. In the later popular version of their monograph, they express the same opinion and again pass in silence by all the fi nds of rat bones from Roman England and Northern Europe.174 Despite the fact that animal bones, especially of small animals, have attracted the interest of archaeologists and osteologists only in recent decades,175 it has been shown that the black rat was widely dispersed in Roman Europe, from Italy to England, to “Belgium” and the Netherlands and all over Roman Gaul in the west to the Roman military settlements on the borders with the Germanic tribes along the R. Rhine and the R. Danube. Th e pattern of fi nds in time and space indicates that the black rat was spread over Roman Europe by the movement of the legions, by their long logistical train of wagons with suffi cient food stuff s to support 4000–6000 men in each legion over time, and through the market-oriented network that was established by the Roman Empire. Th is is one of the important observations that McCormick and I made independently.176 Th is is really not surprising in view of the fact that there was no commercial (or military) sailing from the Mediterranean to western and northwestern Europe, and legions and goods moved by land from Italy to Britain, to Gaul and Roman Germania. Up to 1984 when Twigg’s monograph was published there had been six fi nds in England of skeletal remains of the black rat dating back to the Early Middle Ages, and also one fi nd in Ireland. As mentioned above, at Walton, Aylesbury, fi nds were made dating back to the 5th– 7th centuries, the late Roman period or transitional early Anglo-Saxon England, while other fi nds at this location date to the 9th–12th centuries, indicating a continuous presence. Twenty-seven fi nds dating back to the 11th–15th centuries with a wide territorial distribution in England have also been made.177 Aft er 1984, many new fi nds of remains of rats have been made in England from Anglo-Saxon times

173 Scott and Duncan 2001: 56. 174 Scott and Duncan 2004: 174–5; Davis 1986: 463–4. 175 McCormick 2003: 6. 176 McCormick 2003: 9; Benedictow 2004: 22. 177 Armitage, West and Steedman 1984: 381; Rackham 1979: 112–20; Audoin- Rouzeau and Vigne 1994: 129–35; McCormick 2003: 6, fn. 7.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 129 and subsequent periods of the Middle Ages. Th ey show a wide distribution in the country, as far north as the Brough of Birsay on the western tip of the main island of the Orkneys where they dated back to the 9th–12th centuries.178 Nonetheless, Scott and Duncan state that Dr Twigg has continued with his careful study of the black rat in England during the age of the plagues and has collated overwhelming unpublished evidence that it did not spread to rural areas.179 Th is raises a number of questions: How can Twigg maintain that the black rat only had had a sporadic incidence in English ports in the Middle Ages and later, when the material skeletal fi nds on the ground prove a much longer history of wide distribution back to Roman times, also in inland regions, when he shows knowledge of several of the studies that present this evidence?180 How can Scott and Duncan refer to “overwhelming” unpublished evidence collated by Twigg which confi rms that rats did not spread to rural areas in the face of substantial published empirical zoo-osteological evidence to the contrary? How could Twigg collect and collate “overwhelming” evidence bearing on the matter which is unknown to archaeologists and osteologists who would have had to produce it? And why is this “overwhelming” material still not published? Fortunately, Scott and Duncan mention two arguments based on Twigg’s unpublished material which aff ord the opportunity to test its quality or tenability, especially since these arguments must be assumed to have been selected for their importance and evidentiary powers. Conspicuously, these arguments have no relation to zoo-osteology or fi nds of rat bones, which presumably would be the only powerful material evidence in this case. Instead, these two supposedly important pieces of evidence relate to (1) changes in the design of dovecots in the 1720s and (2) changes in the design of storage facilities for grain in 1730s, which purportedly constitute proof of the normal absence of the

178 James 1999: 20–1; James 2001: 12; Audoin-Rouzeau and Vigne 1994: 129–31; McCormick 2003: 7–9. McCormick’s information is not as well arranged and easily surveyable as that of Audoin-Rouzeau and Vigne and therefore not easily structured and summarized at the level of fi nds, but is updated and contains more valuable perspectives and analyses. 179 Scott and Duncan 2004: 175. 180 Twigg 1984: 80–1.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 130 chapter three black rat back in English history. It is also asserted that these two developments refl ect the contemporary spread of the brown rat which arrived in England in 1728 or 1729. Th ese two arguments contain several elementary methodological fallacies. Th e notion that observations regarding technological developments in the third and fourth decades of the eighteenth century can prove anything about reality in Roman, Anglo-Saxon, medieval or Early Modern Periods in England is obviously untenable. Th e argument that the advent of the brown rat in 1728 or 1729181could be the cause of widespread change in the construction of dovecots in England in the 1720s is obviously also an anachronistic assumption of causation and as such fallacious. Th e idea that a tiny and growing number of brown rats which probably numbered in the hun- dreds and was distributed over a tiny area in the course of the 1730s could aff ect how grain was stored in England in the 1730s refl ects the same temporal problem of causation but also again the fallacious anachronistic implication that it would have evidentiary relevance for a discussion of the presence of black rats in preceding historical periods. Th e explanatory potential of the modernization of mentality and culture in the early phase of the Industrial and Scientifi c Revolutions should also be considered. Th is could make it clear that these authors will have to device a methodologically tenable research strategy that will uncover material with unambiguous evidentiary and explanatory powers relating concretely to the historical process in question. To my knowledge, a generation later Twigg has still not published his purported material, the outcome of his “careful study of the black rat in England,” although Scott and Duncan characterize these two arguments as “splendid pieces of scholarship.” In conclusion, it can be emphasized that despite the fact that animal remains have only quite recently attracted the interest of archaeologists and osteologists,182 it has been shown by numerous fi nds of skeletal remains that the black rat was widely dispersed in England in Roman times and was distributed all over the country in the Middle Ages. Th e diff erence in the incidence and distribution of fi nds between these two historical periods is probably due to two facts, fi rstly that there are fewer physical remains from Roman England than from medieval England that can be examined and, secondly, that Roman remains have

181 Shrewsbury 1971: 9. 182 McCormick 2003: 6.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 131 attracted relatively greater interest from English archaeologists and to a greater degree had been excavated before they started to take interest in small bones, and relevant skeletal material has inevitably been destroyed en masse. From the Roman border provinces, the black rat could easily have been spread further into Germanic and Slavic territories through trade. Actually, remains of black rats dating back to late Roman centuries have been found in the excavation of a Germanic settlement at Wal- tersdorf in eastern Germany near present-day Berlin, and in Slavic settlements in present-day northwestern Poland (Smuszewo) and on the eastern side of the Gulf of Gdansk (Tolkmicko). Th ere has also been a fi nd in Szczecin (Stettin) dating from the 4th–8th centuries. Th us, it is not surprising that numerous fi nds of skeletal remains of the black rat dating back to the early medieval period have been made in northern and northeastern Germany, and in Poland, including sites on the Baltic Sea.183 In the most important commercial centre in Northern Europe in the Early Middle Ages, namely the town of Haithabu situated north of present-day Hamburg, several fi nds of skeletal remains of the black rat have been made.184 From this important commercial centre black rats must have been distributed into the Nordic countries by ships—the black rat is not only the house rat but also the classic ship rat. Again, a long temporal process of spread and adaptation is indicated. Th e lines of trade and communication extended much farther around Northern Europe: Franks and Frieslanders traded with the Nordic countries in the Early Middle Ages and the Vikings sailed all around Western Europe trading and plundering as they saw fi t. In the 880s, the Norwegian merchant Ottar who lived in northern Norway, visited King Alfred the Great of Wessex in England. He told the king about Norway and the other Nordic countries, an account that was included in the geographical section of the translation of the Roman author Orosius’s History of the World, a project in which the king eagerly participated. Ottar’s account produces a vivid picture of trade by ship that in the ninth century interconnected the whole of Northern and northwestern Europe in a commercial network along which black rats, the classic ship rats, would almost inevitably have been widely distributed.

183 Teichert 1985. 184 Reichstein 1974 and 1987.

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Against this backdrop, it is unsurprising that fi nds of black rats in the Nordic countries date back to the Early Viking Age. Recently the archaeologist B. Wigh published a monograph on excavations at Birka, an urban centre which developed in the second half of the eighth century on an island in the big L. Mälaren west of present-day Stockholm. Within a chronology of stratigraphic phases he reports that the remains of a rat were found in phase 3 covering the period c. 810–30 a.d., thir- teen remains of four rats were found in phase 4, a stratum pertaining to c. 830–45 a.d., the remains of another rat date back to the subsequent phase 6, the period c. 860–900, and from phases 7–8 covering the period 900–50 twenty-four bone fragments of black rats were identifi ed,185 before the town disappeared around 975.186 Finds of skeletal remains of the black rat dating back to the end of the Viking Age around 1050 have been made in other urban centres, in Lund187 near the western side of the Sound, and in Sigtuna situated on L. Mälaren north of the former town of Birka and northwest of present- day Stockholm. As mentioned above, twenty-two bone fragments of rats of which fi ft een were identifi ed with certainty as black rat have been found in a special study of a tiny part of the excavation area in Sigtuna. Within this area, the bone fragments were quite dispersed and presumably represent several specimens. Th ese finds suggest that black rats were ordinary animals in the urban environment of the time.188 In all three cases, the presence of the black rat in these urban centres occurred quite early in their developments, and they may have been present about as early as urban growth fi rst started, which appears to have been the case in Birka. Th e appearance of rats in the fi rst phase of the formation of new urban centres in the Viking Period indicates that rats at the time were widespread and usual on board ships and were easily spread to new ports that would act as epicentres of spread inland with the further distribution of goods by boats or pack horses. Also the remains of two rats datable to 1220–60 have been found in Lund.189 Large numbers of skeletal remains of the black rat dating back

185 Wigh 2001: 29, 54, 125–6. 186 A small fi rst excavation at the location was performed in the early 1870s and among the fi nds were the remains of a rat, but since the fi nd was not handled according to modern standards nothing more can be said than that it dates from the ninth or tenth century. See Wigh 2001: 29, 125; and Audoin-Rouzeau and Vigne 1994: 129. 187 Bergquist 1957: 98–103. 188 Hårding 1992: 27; Hårding 1993: 25. Cf. Wigh 2001: 125. 189 Bergquist and Lepiksaar 1957: 11–84.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 133 to the thirteenth century and the late medieval period have been found in excavations in Stockholm.190 Excavations of a settlement on the Baltic island of Öland unearthed the remains of three rats dating back to the 11th–13th century.191 In excavations in Visby in Gotland Island, G. Malmborg, the osteologist at the University of Gotland, has in recent years found many remains of the black rat from the 13th and 14th centuries. In a personal communication, he states that he fi nds it improbable that the black rat was not spread to all parts of the island in the medieval period, and suggests that the brown rat did not arrive until around 1800.192 Remains of two black rats from the decades around 1400 have been found in Hälsingland,193 a completely rural region along the Baltic coast in northern Sweden, namely in the royal bailiff ’s fort at Faxeholm,194 aft er only four per cent of the site has been excavated.195 J. Lepiskaar, the osteologist, has identifi ed the remains of twenty rats found in the site of a monastery in Gudhem in western Sweden (specifi cally the southwestern region of Västergötland) dating back to the fourteenth and fi ft eenth centuries. Th e same scholar found bones from a rat in Uppsala north of Stockholm datable to the fi ft eenth century and another from about 1470–1530 at a nunnery in Ny-Varberg, a small town situated on the Sound (close to Varberg).196 A fi nd of rat bones in the site of a hostel for travellers in Ramundeboda in the district of Tiveden, in a central region of Sweden (county of Örebro) is dated to the fi ft eenth century197 (Ny-Varberg and Lund are situated in regions that today are Swedish but in the Middle Ages belonged to the Kingdom of Denmark). Finds of rat bones in Sweden now date back to the early Viking Period and throughout the whole medieval period; they have a wide territorial distribution from Scania in the southwest to Hälsingland in the northeast. Th ese fi nds were made in both urban and rural ecological environments. Th is corresponds to interesting linguistic evidence

190 Vretemark 1983: 294, 467. 191 Boessneck and von den Driesch 1979: 214–5. 192 Personal communications from G. Malmborg in e-mails dated 19 June, 20 June and 21 June 2006. 193 Hälsingland is situated roughly 250 km north of Stockholm. 194 Faxeholm is situated not far from the present-day small town of Söderhamn that, please note, was established at the beginning of the seventeenth century. Faxeholm was quite a small and simple fortifi ed place, not really a castle. Mogren 2000: 251–2. 195 Mogren 2000: 119–20, 249. 196 Lepiksaar 1965: 96–7; 1969: 38; 1975: 230–9. 197 Audoin-Rouzeau and Vigne 1994: 131.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 134 chapter three which needs some general introductory comments. Th e major language families do not contain a specifi c word for rat in their basic vocabularies. In the past, people were not zoologists and had no scholarly or scientifi c education, and they used the same word to designate a number of animals that looked quite alike to them such as mice, rats, stoats and polecats. In languages of Indo-European origin, the basic word is “mus,” e.g., in Latin, Norse and modern Scandinavian languages “mus,” German “Maus,” English “mouse,” Russian “mysh.” Up to 1910, the scientifi c name of the black rat was Mus rattus and of the brown rat Mus decumanus. For this reason, it is oft en impossible to know which animal a writer has in mind when the word “mus” or “mouse” is used.198 When a writer for some reason wished to be more accurate, additional information was needed to identify the specifi c animal referred to. Medieval authors writing in Latin might resort to the current vernacular word: a chronicler provides an account of an Irish bishop of the fi ft h century whose library was destroyed by majores mures que vulgariter rati vocantur, i.e., “big ‘mice’ that in the vernacular [by common people] are called rats.” Th us, in fi ft h-century Ireland, ordinary people had acquired a specifi c word in order to distinguish vermin in the form of mice from vermin in the form of rats, probably from the Anglo-Saxon invaders who appear to have had such a word.199 Also in the Norse language of the Vikings a specifi c term came into use when people wished to identify the animal in question as a rat (long before the word rat entered the Scandinavian languages), namely “vǫlsk mus” which can be literally translated as “Frankish mouse.”200 In view of what we know of the history of the brown rat, there can be no doubt that this term refers to the black rat. Th e adoption of the term may refl ect either the fact that the black rat was a new animal in the early Viking Period or that the Vikings learned a specifi c term abroad that they found useful. Th e term “Frankish mouse” may contain some indication of the geographical origin and the time of frequent and widespread introduction of black rats to the Nordic countries. It suggests that the time was the Viking Age, quite likely in the fi rst half of the ninth century, when Viking fl eets frequently sailed up the large French rivers, landed hosts of armed men which ravished the countryside and formed armies which besieged Paris. Since the black rat is not only the

198 Cf. for instance McCormick 2003: 4. 199 McArthur 1949: 170, fn. 2. 200 An Icelandic-English Dictionary 1975: 440, ‘mýss valkar’; Fritzner 1954: 755.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 135 house rat but also the ship rat, this means that there must have been many introductions of black rats into the Nordic countries as early as the ninth century and also frequently later, also from other sources, for instance, from Haithabu or England. Th is explains the frequent archaeological fi nds of rat bones from the early ninth century and later periods. Th ese were rats which would have had centuries of adaptation to the climates of northwestern France, England, and northern Germany. Consequently, there would also be ample time for the evolutionary development of an even more hardy and rough-coated breed of black rats that would have been adapted to life under the prevailing climatic, economic and social conditions of the Nordic countries. Th is process would allow the development of a widespread and numerous population of rats and the murine potential which could play a tragic part in the spread of the Black Death and subsequent plague epidemics. Th e early introduction of the specifi c term “vǫlsk mus” is probably the reason that the word “rat” is not registered Scandinavian sources until the Late Middle Ages.201 Th e numerous fi nds of medieval rat bones in the Nordic countries present the proponents of alternative theories with great problems which they handle in interesting ways. Davis discusses Scandinavia in this regard under the pretence that there has been made only one fi nd of rat bones, namely in Lund, despite the fact that quite a number of the fi nds of rat bones presented above had been published before he wrote his paper. It is not true that Lund is a port, as Davis maintains:202 Lund is situated on a fertile plain about eight km from the Sound without pronounced commercial functions. In the Middle Ages, Lund’s growth was mostly stimulated by its establishment as a national religious centre, a cathedral city, and as the site of the archdiocese of Denmark. It is not readily comprehensible what Davis means in this context by stating that “none were found in Holland” which is a province in the Netherlands. Perhaps, it is a garbled form of Halland which is a longish region (at the time Danish) situated along the Sound (north of Lund), in which case he is wrong, since Ny-Varberg was a small town in Halland near present-day Varberg. Relating to my discussion of the presence of rats in the medieval Nordic countries in my doctoral thesis,203 Cohn asserts in his

201 Bernström 1969: 578. 202 Davis 1986: 463. 203 Benedictow 1993/1996: 157–60.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 136 chapter three monograph that in “these Nordic countries no skeletal remains of rats has been found.”204 Clearly, this assertion is wrong. Most of the fi nds of skeletal remains of rats mentioned above were published before I wrote my thesis and they are all included in my presentation of this material with a discussion of their epidemiological implications. At the time Cohn was writing his monograph, he had the opportunity to avail him- self of the overview of archaeological fi ndings of black rats published by Audoin-Rouzeau and Vigne in 1994 in which my information on Nordic fi nds is included and greatly enlarged upon within a Europe- wide perspective, and subsequent publications of fi nds up to 2002. Instead, he denies the facts and makes disparaging comments on the earnest eff orts of colleagues to interpret the signifi cance of these nds.fi In my doctoral thesis I argue that the absence of fi nds of rat bones in Norway so far was probably due to the incipient stage of development of zoo-archaeology, and for this view I am ridiculed by Cohn.205 However, at the time Norwegian archaeologists had not begun search- ing for and studying small bones in their excavations; such bone material might be collected and stored but was not actively studied. In recent years, the study of such bone material has begun, in the words of Ann Kristin Huft hammer, the osteo-archaeologist who has taken the rstfi initiative in this fi eld of study in Norway: “only recently have we begun to sieve and systematically collect bones also of small species.”206 Up to the time of writing, this has led to the following identifi cations of skeletal remains of the black rat: in Trondheim (medieval name Nidaros) skeletal remains of the black rat have been found in several sites from the early High Middle ages, among them in the sites of Folkebibliotekstomten and Televerkstomten; fi nds have also been made in sites from the seventeenth century in the archiepiscopal man- sion and in Televerkstomten. In Stavanger, rat bones archaeologically dated to the early twelft h century have been found in strata at Skagen. Th e oldest radiological dating of bone material of a black rat in Bergen is 750 years before present time, calibrated to ad 1225–95. In Tønsberg, archaeologists have succeeded in fi nding a rat nest containing several individuals. Skeletal remains of a rat found in it have

204 Cohn 2002: 53. 205 Ibid. 206 Personal communication from Ann Kristin Huft hammer by e-mail of 10 January 2006.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 137 been radiologically dated to 700 years before present, calibrated to ad 1265–1375.207 It is tempting to consider this fi nd a possible refl ection of the Black Death. Th e fi nds of medieval rat bones in Norway are consonant with literary evidence. In Snorri Sturluson’s Saga of St Olav, the need for a specifi c designation of rats is resolved by using the description “mice as big as cats” with obvious resemblance to the Latin wording of the Irish chronicler mentioned above mures majores, “big mice” (in the vernacular called rats). Th is description is used for animals which are said to have appeared when St Olav crushed a big wooden statue of the god Th or to which food was sacrifi ced daily.208 Th is brief legend of St Olav linked to his missionary work takes place in the principal inland valley of Gudbrandsdalen, a completely rural region of central southern Norway. Th is implies that at the time this saga was written, i.e. shortly before 1230, the listeners or readers were comfortable with the notion that rats were usual animals in central rural districts of southern Norway and that this had been the case two centuries earlier. When rats surface in this saga, it is in a context that demonstrates the ordinary presence of rats in the middle of the high medieval Norwegian countryside. Again, the crucial source-critical question is: why are rats mentioned? Sagas are heroic tales of kings and warriors and serve the ideological and political purposes of state-building and of confi rming the prestigious (and profi table) roles of kings and aristocratic elites. Comments on rats have no useful practical or ideological place in this literature and should not be expected to occur, particularly as they were pests in human habitats. In this case rats are mentioned because they serve a religious propagandistic function, demonstrating the stupidity of serving food to heathen wooden gods. Th e great saga writer who constantly seeks literary eff ects does not use the term “vǫlsk mus” because he wishes to dramatize his story and enhance the impact of its moral teaching by emphasizing the ludicrous point that the heathen peasants had fed rats so lavishly that they had grown big as cats. Th e question of evolutionary adaptation to northerly climates by rats and the quantitative and distributive aspects of their presence in the Nordic countries can be enlarged upon on the basis of written sources. Th ere are so many references to rats in literary works that a leading

207 Personal communications by e-mail 10 January 2006. 208 Snorri Sturluson 1899/2003: 295.

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Swedish scholar in this fi eld of study concludes: “During the late medieval period, rats and mice are mentioned as generally known pests in and around human buildings”; and “it appears likely that this animal [the black rat] at the middle of the fourteenth century had a numerous presence in Scandinavia’s and Denmark’s rural districts.”209 “Rats and even mice must have been very troublesome pests for medieval man,” as evidenced by both the great number of maledictions and curses and also the extensive use of rat traps.210 For zoo-historical reasons, all of these references must be to the black rat. Th is literary evidence and the conclusions drawn by Nordic scholars with respect to the quantitative aspects of the presence of black rats and their territorial distribution in the Nordic countries accord with the material fi nds of rat bones, and we may be certain that rats had a broad rural presence. Th is presentation of skeletal remains of the black rat so far found in Norway and Sweden puts in perspective Twigg’s assertion that Norway and Sweden are countries “which provide especially poor conditions for Rattus rattus,” and makes it clear that his view is based on precon- ceived and arbitrary assumptions which are at variance with historical reality as refl ected both in the form of rat bones and in literary sources.211 Th is confi rms O. Nybelin’s view which he formed long before archaeological fi nds of rat bones were made to the eff ect that the black rat was spread all over medieval Sweden and the southern parts of Norrland. To him it was important that this was still the case in large parts of Sweden in the nineteenth century, but at the time the black rat was in rapid decline because of the expansion of the brown rat and the modernization of housing. Nonetheless, the black rat was still observed in inland rural regions with very cold winters such as Värmland and Småland, and at the time it was still common in southern Norrland, especially in Hälsingland. Actually, in Hälsingland the black rat was still living in four rural parishes in the early 1920s as well as in seven rural parishes in Halland, in northeastern and southwestern Sweden respectively. In Finland, black rats were observed in about 20 localities, mostly in rural regions, in the fi rst decades of the twentieth century.212 For obvious reasons, the brown rat spread fi rst to ports and urban

209 Bernström 1969: 577–83. My translation from Swedish. Törnblom 1993: 367. 210 Berg 1969: 576–7. My translation from Swedish. 211 Twigg 1984: 57. 212 Nybelin 1928: 852–5.

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centres and from there to rural districts, thus, logically the last surviving “tribes” of the old black rat were found in peripheral rural districts. However, this also constitutes evidence that the black rats in the Nordic countries were spread all over these countries, and that they were usual rural animals not at all confi ned to ports or urban centres. Sweden and Finland have colder winters than large parts of Norway because they are situated further way from the warming eff ects of the Gulf Stream.213 In this respect, there is complete compatibility and accordance between the written sources and the material fi nds of skeletal remains of these animals. Th is point should be considered from wider chronological and geographical perspectives. Until the 1790s, the black rat was the only rat in Sweden and Finland, the Nordic countries with the coldest winters. Th e arrival of the brown rat meant that the black rat was gradually driven from its habitats by the brown rats, and was prevented from seeking alternative refuge or habitats by contemporaneous changes in the construction of buildings and increasingly hostile countermeasures implemented by the human inhabitants against rats in their houses and immediate vicinities However, in the fi rst decades of the twentieth century black rats were still found in a number of urban and rural areas in these countries; in Sweden the last colonies could still be observed in the 1950s.214 In Norway, the black rat may possibly still live in a few rural localities.215 In the Middle Ages, Finland had a tiny and territorially widely dispersed population numbering about 65,000 persons at the time of the Black Death. Th ere was only one small urban centre, namely Åbo (Turku),216 consequently, rats would have to be animals living in conjunction with rural human settlements. In fact, black rats were still observed in the remote rural districts of the region of Tavastland in Central Finland in the 1920s.217 Presumably, rats were introduced into Finland by Swedish peasants who moved across the Baltic Sea and

213 Eldevik 2006: 48. Eldevik is researh leader at the G.C. Rieber Climate Institute at the Nansen Environmental and Remote Sensing Center and Bjerknes Centre for Climate Research. Th e average temperature in these parts of Norway is 10 °C higher than other regions situated at the same northerly latitudes. 214 www.skansen-akvariet.se/vara_djur/html/svartratta.html 215 Personal communication from Rolf Lie, Zoological Museum, University of Bergen, in 1991. 216 Benedictow 2004: 216–7. 217 Vilkuna 1969: 584.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 140 chapter three settled there in the Viking Period, but, of course, these rats might have a much longer history. And these black rats were also burrowing and living in the vicinity of human habitation,218 despite Twigg and Davis’s assertions to the contrary.219 Davis actually consistently calls the black rat a “roof rat.” As shown above, the black rat can, in fact, freely burrow, in nature as peridomestic rodents and in beaten earth fl oors and walls of human housing220 on the condition that they are not exposed to brown rats which will hunt them down, kill them or drive them out of their burrows, and that would not happen before the late eighteenth century in Europe. As mentioned also above, in Macquarie Island which is situated quite close to Antarctica (54° 30ʹ S, 158° 57ʹ E), in a very inhospitable cold climate and subantarctic ecology, thriving colonies of black rats have settled as burrowing rodents, temperatures in the burrows ranging from 4.8 °C. to 9.2 °C.221 Largish specimens of the black rat have been found in England at Faccombe Netherton on the Hampshire-Berkshire border,222 among the Norwegian fi nds in Bergen and the Swedish fi nds in Visby,223 and also in Corsica (see above). Th is can be taken as further evidence of the adaptability of rats by selection, which also adapt by size to environmental challenges by selection of larger animals with improved chance of survival in competition with other small rodents and which would make them less vulnerable to small predators like stoats or polecats. Perhaps rounding off of body-shape could also increase resistance to cold (which could not have been a selective factor in Corsica).224 Under the circumstances, the wide geographical spread and the substantial number of fi nds of medieval rat bones in the northerly parts of Europe are quite remarkable. In the words of McCormick: “Judging from 143 rat contexts of the ninth to the fi ft eenth centuries, medieval Europe’s rat colonies were extensive and abundant […].” And these

218 Nybelin 1928: 850–7; Bernström 1969: 578–9, 584; Vilkuna 1969: 583–4. 219 Twigg 1984: 80; Davis 1986: 456–7. 220 See. for instance, IPRC 1907 g: 746; Lamb 1908: 9, 13. 221 McCormick 2003: 22–3. 222 James 2001: 12. 223 Malmborg, personal communication by e-mail 19 June 2006: “Even here we have a morphological variant which appears a little larger than the black would be expected to be.” My translation from Swedish. 224 I have noted with interest that the IPRC found that black rats in Belgaum 400 km southeast of Mumbai were much larger than in Pune (Poona) about 120 km southeast of Mumbai. IPRC 1910c: 456.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 141 rats were not far and few between at the time: in sixty-six cases the archaeologists estimated the minimum number of individual rats, which proved to be 601 rats or an average of 9.1 per site, and twelve of the most-infested sites were from the thirteenth century or later. “Overall, the raw rat counts hint at hugely expanding rat populations around the fourteenth-century plague.”225 Clearly, the arguments of the advocates of alternative theories against a numerous and broad presence of the black rat in medieval Europe, including in the northerly parts and in the Nordic countries, are not tenable and represent serious underestimation of “rats’ adaptability” by evolutionary selection and the development of regionally adapted variants or biovars.226 As pointed out above, this is also the case with rat fl eas, X. cheopis: “As shown by its wide geographical distribution, X. cheopis is able to adapt itself to a considerable range of climatic conditions. It is, as has been previously noted, the common rat-fl ea in Manchuria and is also the prevalent species in the tropical section of Brazil.”227 Th is shows that a full potential for epidemics of bubonic plague must have been present in the Scandinavian countries at the latest from the High Middle Ages. Th is does not prove that epizootics among rats fuelled historical plague epidemics, but does constitute crucial evidence which permits solid assumptions to the eff ect that there was a suffi cient murine basis all over Europe, that the potential for epidemics of bubonic plague was present. Whether or not this potential was realized must be demonstrated through manifestations of the epidemiological processes that are explicable only by a concomitant epizootic of plague among rats. Central aspects of this question will be discussed in the next subchapter on the sociology of rat-based plague, and in Part 4 on defi ning features in chapters on epidemic latency periods and other temporal aspects of the development of plague epidemics, the inverted correlation between population density and morbidity and mortality rates in modern as well as historical epidemics of plague, and on the seasonality of plague epidemics, and elsewhere. Assertions that historical plague epidemics could not have been bubonic plague because there was not a murine basis must be rejected.

225 McCormick 2003: 14. 226 McCormick 2003: 22; Wigh 2000: 125; Nybelin 1928: 855. 227 Pollitzer 1954: 327.

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Sociology of Rat-based Plague

Social conditions can systematically aff ect the intensity of infective processes in relation to particular social categories of persons according to the distributive functions of relative risk of exposure. At the heart of the matter is the fact that epidemiology is fundamentally a subdisci- pline of sociology which aims to explain how various social conditions and interrelated patterns of behaviour of human beings, animals and insects aff ect the probability of contagion being transmitted to human beings or between human beings. It is, therefore, important to note Wu Lien-Teh’s general statement: Most investigators are agreed that, on the whole, diff erences in the age, sex, racial and also occupational incidence of bubonic plague are due to diff erences in exposure to infection as brought about by varying modes of life and not to intrinsic causes.228 Pollitzer supports this position unequivocally when he cites it quite closely: “Most workers are agreed that diff erences in the race and sex incidence of bubonic plague cases, as well as […] among certain occupational groups […] are due merely to diff erences in the degree of exposure of the various groups to the infection and not to intrinsic causes.”229 Population density aff ects the intensity of social interaction and therefore also the probability of being infected and also of being infected repeatedly and, thus, by multiple infective doses, which produce diff erent morbidity and lethality rates according to social class and other social categories. Th is explains the typical supermortality in epidemic disease of indigent and destitute people who tend to live in overcrowded rooms and in overcrowded quarters. On the other hand, diseases spread by cross-infection may also neg- atively aff ect the affl uent classes who tend to have large households with several or many servants and an active social life, producing a high level of social interaction and a corresponding increase in exposure to contagion by droplets. R. Schofi eld remarks in his study of the plague epidemic in Colyton on the sociological dimension of epidemiology that “men and women living in isolated farmsteads may be less

228 Wu Lien-Teh 1936c: 399. 229 Pollitzer 1954: 503.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 143 likely to meet infected people than would those living in a village street. Also the chance of catching a disease may […] vary systematically with the social and economic status of the household.”230 R. Engelsen found that affl uent or well-to-do farmers in Norway at the end of the eighteenth century had a slightly higher risk of contracting infectious diseases than the poor rural classes who tended to live more isolated on their sub-tenancies (“undersettles”) or small holdings.231 Th is pattern of social variation in the incidence of epidemic disease is basically associated with risk of exposure. Th is demonstrates the important point that risk of exposure in relation to diseases spread by cross- infection, by droplets or inter-personal physical contact should be expected to produce clearly diff erent social manifestations from the pattern of epidemic bubonic plague disseminated and transmitted from rats by rat fl eas to human beings. Sticker, summarizing in his big two-volume work of almost thousand pages an almost incomprehensibly wide reading of sources and studies written in classical and modern European languages, pointed out the great variation in the incidence of plague among people of dif- ferent occupations. Persons working with food stuff s and in environments where food is stored, bakers, millers and butchers, were particularly at risk of contracting the disease and dying from it.232 In E. Woehlkens’s outstanding study of plague in Uelzen (northern Germany), six of seven bakers, ten of twelve linen weavers, and fi ve of six butchers died in the plague epidemic of 1597 but only two of nine smiths, and only four of the town’s fi ft een carpenters, wheelwrights and coopers.233 Th is is clear evidence of the workings of the rat epizootic associated with an epidemic of bubonic plague, because the activities of some occupations attract rats while the activities of other occupations drive them away. Bakers, linen weavers and butchers are very vulnerable to plague disease because their work material is highly attractive food for rats (fl ax seeds in the case of linen weavers), while the shops of smiths, coopers and wheelwrights do not contain signifi cant amounts of edible material attractive to rats, and rats avoid high sharp sounds produced by their work, so these occupations are little exposed to rats. Th us, the human sociology of a plague epidemic refl ects the sociology

230 Schofi eld 1977: 103–4. 231 Engelsen 1983: 161–202. 232 Sticker 1910: 266–8. Cf. Mate 1984: 351–2. 233 Woehlkens 1954: 72–5.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 144 chapter three of rats which is infl uenced by human activities which are attractive or repellent to rats. Woehlkens who could follow the spread of the epidemic house by house concluded that the direction of spread of the epidemic, the formation of new centres in the specifi c phases and the progress from block to block were determined by the localization of these houses: the topographic course of plague was governed by the places with the highest accumulation of food stuff s for rats (bakers, linen weavers, butchers). A comparison of average numbers of deaths shows that the probability of being killed by plague in such a place was more than fi ve times higher than in the case of occupations working with wood or iron.234 Th e crucial sociological point is that this diff erential pattern of mortality among various occupations and types of artisans or craft smen can be easily explained as refl ections of rat-borne plague transmitted by rat fl eas, and is inexplicable as refl ections of a disease spread by cross- infection. Th is pattern constitutes therefore sociological evidence of bubonic plague. Woehlkens makes also quite a number of other observations that refl ect the workings of rat-based plague, for instance that the affl uent citizens who lived in housing of stone or bricks with tile- covered roofs were largely spared by the epidemic while poor people living in housing suitable for nesting of rats were violently attacked, a pattern that also took the form of strongly diff erential mortality according to social-class divisions by side of street.235 Notable is also the formation of new centres of spread, demonstrating metastatic spread of plague by transportation of rat fl eas. Cohn has not noted this important aspect of supermortality among occupations working with food stuff s attractive to rats and submortality among occupations repellent to rats. In his discussion of diff erential mortality among occupational categories, he is only able to mention supermortality among professions like notaries, attorneys, and parish priests on the one hand, and of gravediggers according to two chroniclers and of wax chandlers of London according to an “apocryphal” personal communication, on the other. Wax chandlers are supposed to suff er supermortality because they did not only supply candles for funerals but also quite remarkably are asserted to have embalmed

234 Woehlkens 1954: 74. My translation from German, and my italics. 235 Woehlkens 1954: 70–1.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 145 bodies,236 which may be the reason that such assertions have not been accepted for publication. Th e point is that supermortality among these professions does not obviously imply the role of rats and their fl eas but can be associated with diseases spread by cross-infection and pro- fessional exposure; in the case of gravediggers and wax chandlers they are surprisingly supposed to contract the disease from dead bodies. However, Cohn must ignore the fact that these professionals would tend to enter houses with persons dying or dead from plague and that this behaviour would produce high exposure to infective rat fl eas. If we take seriously the assertions with respect to gravediggers and to wax chandlers in the purported role of embalmers, one must also take into account the possibility that they could be infected by rat fl eas hidden in the clothing of dead plague victims. On page 122, Cohn maintains that gravediggers according to two chroniclers suff ered great supermortality in plague because this seemingly serves his case for cross-infection. However, on page 138 he cites another chronicler to the eff ect that he “marvelled at the gravediggers, who he said were rarely struck by plague or died from it by his day (the mid-fi ft eenth century),” because this dia- metrically opposite view now seemingly serves his argument for immunity among survivors. Th is is just one of many instances of weak consistency and high tolerance of cognitive dissonance in Cohn’s work, since his selection of material is governed by his ambition to establish a pre-conceived revolutionary theory of historical plague. He only cites occupations or professions with supermortality or a pattern of death which seem at least superfi cially to suggest cross-infection; why butchers, bakers, millers, linen weavers, and so on, should suff er supermortality from cross-infection and smiths, carpenters, wheelwrights and coopers should on the contrary suff er submortality is not readily understandable. In fact, only bubonic plague can provide a cogent explanation for these patterns of occupational supermortality and submortality. In his study of the plague epidemic in Colyton 1645–6, Schofi eld puts forward a working hypothesis which predicts that, among other things, “diseases like bubonic plague and typhus [transmitted by insect vectors] are likely to be associated with geographically clustered patterns of death, while airborne infections, such as infl uenza, will show much less clustering.” As shown in quite some detail above, Schofi eld

236 Cohn 2002: 121–3.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 146 chapter three succeeded in uncovering the typical pattern of clustering in families characteristic of rat-born plague transmitted by rat fl eas.237 Dijkstra carried out a study of the pattern of spread of plague in the Jordan quarter of Amsterdam during the epidemics of 1617 and 1624. Th e clustering of plague cases, the contiguity of spread, and the type of progression showed that “plague in the seventeenth century has been dependent on rat plague.” As the Jordan quarter had changed little physically between the seventeenth century and the fi rst decades of the twentieth century, he is able to elaborate further on the topic of epidemic spread. With a number of maps he illustrates the strongly con- trasting patterns of epidemic spread in Jordan during the plague epidemics of the seventeenth century on one hand, and the infl uenza epidemic in 1918 on the other. Th e latter represents the pattern pre- dicted by the interhuman model of transmission and dissemination.238 As a part of her dissertation on epidemic diseases in early Renaissance Florence, Carmichael conducted a study of the spread of plague in the quarter of Santo Spirito during the minor epidemic of 1430. In my opinion, the pattern agrees closely with the fi ndings of Dijkstra, Woehlkens, Slack (see immediately below) and Schofi eld. Th e extreme local character of dissemination, the initial clustering of deaths in one part of this traditional working class district and even along certain streets within this small area, the clustering of plague deaths within some families even as the immediate neighbours escaped unharmed, the slow progression of the epidemic, and the impression that many streets seemed to begin to function as local plague foci as the epidemic spread through the summer months, all point to the same explanation. Th e maps showing the spatio-temporal progression resemble quite closely the maps of Dijkstra and Woehlkens. Slack’s analysis of plague in Bristol in 1540–60 also provides acute observations of rat-borne plague and the relative risk of exposure of various social classes. He could identify the typical slow spread of plague which refl ected its movement through contiguous rat colonies: “Th e disease was carried relatively slowly through the town by rats,” and it “moved haphazardly, sometimes missing out two or three households in its progress along a street.” He registered sudden leaps to a house surrounded by uninfected houses,239 which then might or might

237 Schofi eld 1977: 102–8. Above: 62–9. 238 Dijkstra 1921: 64–74. My translation from Dutch. Cf. above: 67. 239 Slack 1977: 53–7.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access rats 147 not start to function as new infective centres of spread. Th e conspicuous outcome of his study is “the variations which emerge between parishes and their apparent coincidence in many cases with social class diff erences. For plague mortality was not spread evenly over the town.” Christ Church parish comprised broad, fi ne streets inhabited by affl u- ent citizens and also the poor and the overcrowded back street of the Pithay: Th e Pithay lost a higher proportion of its inhabitants in both epidemics than any other part of the parish […]. Bubonic plague was concentrated in the back street of this otherwise prosperous parish. Slack concludes in this way: “Plague thus had a socially selective impact on Bristol in these years, and this is important for any understanding of its demographic and economic eff ects.” His sociological explanation of the social variation in plague mortality is clear: Th e vital determinants behind this association were of course variations in standards of housing and hygiene which might attract or repel the rats and fl eas which carried plague.240 Th is view accords with the fact that there exists much evidence showing that ecclesiastics, aristocrats, well-off urban residents and other persons living in houses built of stone or brick in relative terms con- tracted plague far less frequently than social categories living in other types of housing, e.g., the poor in Milan’s “stalli” or in London’s out- parishes.241 Mortality among the English baronage was much lower than among the peasantry.242 A.E. Nash is quite probably correct in assuming that many of them escaped infection because they lived in “stone-built accommodation.”243 Cazelles concludes his study of the diff erential social impact of the Black Death by stating that “the nobility apparently lived through the mortality without signifi cant losses.”244 In the Black Death, monasteries, churches and hospitals in Avignon were left unscathed whilst the city in general was cruelly ravaged. Th is cannot be explained by acquired

240 Slack 1977: 54–7. 241 Cipolla 1974: 283; Cipolla and Zanetti 1972: 201; Bell 1951: Chapters 4, 6, and pp. 158a, 329; Hirst 1953: 128; Dyer 1978: 309. 242 Benedictow 2004: 343, 360–77. See also below: 383–92. 243 In the epidemics of 1369 and 1374, the “lords of the manor” appear to have been left almost unscathed. Nash 1980: 39. 244 Cazelles 1962 (165): 300: “la grande noblesse traverse apparement la mortalité sans pertes sensibles.” My translation from French.

O. Benedictow - 9789004193918 Downloaded from Brill.com09/27/2021 05:40:03AM via free access 148 chapter three immunity, as it was the fi rst plague epidemic in southern France for about 700 hundred years. In the terrible epidemic of 1720–2, mental hospitals and closed monasteries remained untouched. Th e previous epidemic, which killed about 8,000 persons, occurred in 1649.245 Only a very few members of the resident regular clergy (living in a population with an average life expectancy of c. twenty-fi ve years246), could possibly have acquired immunity to plague. Closing such institutions to the outside world would not have provided protection against the plague, if the stone buildings had not prevented rats from entering the premises. In Moscow, the Imperial Orphanage which contained a thousand children and a staff of 400 was similarly spared in the violent plague epidemic which ravaged the city in 1770–1.247 At that time, there had not been plague in Moscow since 1665,248 so neither children nor adults could have been protected by immunity to plague. Th e reason for this pattern is that houses built of stone or brick were far less amenable to rats than houses built of wood or wattle and daub and roofs covered by thatch. In fact, the increasing use of stone and brick for house construction beginning in the seventeenth century was for quite some time the favourite explanation with historians for the disappearance of plague from Europe.249 In more recent times, the IPRC concluded that the extensive use of stone and brick for house construction constituted an important explanation of why East Bengal and Assam were only lightly hit by plague.250 Th is fact is fl atly rejected by Cohn. Encouraged, perhaps, by his being in the favour with the editors of Th e New England Journal of Medicine Cohn apparently does not fear that his scholarly reputation will be aff ected by the following assertion in his review of my monograph on the Black Death:251 Benedictow maintains that people in well-built stone housing were protected against plague because rats could not enter these dwellings. Th e plague commissioners [IPRC: my insertion] again discovered the opposite: that rats penetrated stone and brick houses, even those with cement

245 Colonna d’Istria 1968: 18–9. 246 Fourastié 1972: 30. 247 Sticker 1910: 264; Alexander 1980: 263–4. 248 Biraben 1975: 429. 249 See e.g., Clark and Slack 1976: 142–9; Liston 1924: 902–3; Appleby 1980: 166–7; Slack 1981: 472. 250 IPRC 1911c: 187–92. 251 Cohn 2005: 1354.

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fl oors, infl icting some of the highest rates of death in these residences, whereas oft en some of the poorest people, living in bamboo huts, fared much better. Th e IPRC comments on these matters in Report No. XLVI of 1911, “Observations On Plague in Eastern Bengal and Assam,” in Chapter H. “Th e Causes for the Comparative Scarcity of Rats in the Houses.” In the second sub-chapter titled “Th e Structure of Th eir Houses,” the following statements can be found: the Bengali seems to have adopted a method of house construction which succeeds in practically eliminating rats from his house, be the house a pucca or kutcha one. “Pucca” houses, being built of stone or brick or mortar, oft en with concrete roof, from the very nature of the materials used in their construction aff ord little harbourage for rats. Th ese animals may however eff ect an entrance from outside either through the fl oor or by the door. Many Bengali houses however have been so constructed as to prevent rats gain- ing an entrance in these ways, being built on raised plinths of special construction. Th ese plinths are erected with a brick or masonry facing, along the upper border of which runs a bead of varying depth which projects for from four to six inches or more over the base. Th e oorfl is made of a layer of concrete faced with hard polished cement, below which is a layer a foot or more deep of dry sand. Th ese devices are said to have been adopted for a number of reasons: […] (3) to prevent the access of rats which cannot make their burrows in the sand or climb the overhang- ing plinth […]. Th e “kutcha” houses, too, aff ord little shelter for rats. For, being constructed of thin bamboo matting or wattle covered with a thin layer of mud, the walls aff ord no shelter for these rodents. Th e roofs too, being made of corrugated iron, split bamboo, or thin grass thatch, fail to shelter these animals. Perhaps one of the most noteworthy features of the buildings in this province is the almost complete absence of tiled roofs which are so commonly seen in many other parts of India.252 Th e Commission summarized their fi ndings in its “General Conclusions”: (3) Th e freedom of the province from plague can chiefl y be attributed to the scarcity of rats in the houses as compared with other parts of India […]. (5) Th e structure and design of the Bengali homes, whether it be of the solid masonry type on the one hand or of the fl imsy matting or grass type on the other, aff ord little shelter for rats.253

252 IPRC 1911c: 190–1. 253 IPRC 1911c: 192.

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Th us, Cohn’s assertion on this point is contrary to fact. It is a clear mis- representation of the fi ndings of the IPRC and their unequivocal conclusion which indisputably supports the notion that stone, concrete and masonry protects against rat invasion and the establishment of rat colonies in human habitation. Nothing is said to the eff ect that the small incidence of plague cases in this region was higher in the “pucca” houses than in the “kutcha” houses, as Cohn’s maintains. Th us the sociology of historical plague epidemics exhibits the characteristic refl ections of rat-based bubonic plague and constitutes evidence of the presence of black rats.

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