Plagues and Peoples

by William H. McNeill

  Another and very important change in disease incidence in eighteenth-century Britain, however, was not the result of this sort of unexpected and accidental ecological alteration, but was instead a result of deliberate resort to smallpox inoculation. The practice was introduced into England in 1721. In the next year the royal children were successfully immunized. The method was to transfer the infection by introducing matter from a smallpox pustule into a slight wound made in the patient’s skin. Occasionally the patient developed a severe case of smallpox from such treatment, and some died. But usually the symptoms were slight—a few score of pox only; and immunity proved equivalent to that resulting from contracting the disease naturally.

  The technique was simple, and mass inoculation proved easy to arrange when its effectiveness came generally to be recognized. Hence the practice became widespread in England during the 1740s, and, with improvements in technique that reduced the risk of serious infection to a very slight pro- portion, inoculation became general in rural communities and small towns from the 1770s.

  Interestingly enough, the practice of smallpox inoculation did not “take” in London and other big cities. The unusual situation whereby an innovation spread first in rural and small-town environments and bypassed large urban centers can readily be understood if one remembers the different pattern of incidence that prevailed in the two environments. In big cities smallpox was already a childhood disease; in rural England it remained epidemic, and could therefore attack young adults and adolescents, whose deaths were far more noticed than the die-off of infants. Hence it was in small towns and villages that interest in inoculation centered: it could solve what had remained a serious problem for such communities. In London, however, where the poor were plagued by too many children anyhow, there was no comparable impulse to take deliberate steps against the disease.19

  Deaths from smallpox therefore remained a very conspicuous feature of the London Bills of Mortality throughout the eighteenth century. There, the ravages of the disease only began to diminish in the 1840s, when the safer method of vaccination with cowpox had been introduced, and initial resistances to that procedure had been overcome.20 In rural and small-town Britain, however, inoculation with the smallpox virus itself had become widespread seventy to one hundred years earlier. The result was to reinforce and expand the pattern of demographic growth that the health changes sketched above were bringing to rural England in the same period of time.

  Public opposition to smallpox inoculation lasted much longer on the Continent. Opponents criticized the practice both as an interference with God’s will and as wanton spreading of dangerous infection among healthy people. The latter argument was effectively countered in England by careful (and methodologically path-breaking) statistical studies conducted by the Royal Society between 1721 and 1740; but in France it was not until after the death of Louis XV from small- pox in 1774 that organized resistance to inoculation crumbled. And even then, deliberate immunization against smallpox did not become a widespread practice on the European continent until the nineteenth century.21

  Interestingly enough, smallpox inoculation became significant in the English colonies of America early in the eighteenth century. In America, the fearful power of the disease to kill adults was frequently demonstrated by outbreaks among Indians; and the rural and small-town structure of colonial society, like its counterpart in England, was also very vulnerable to sporadic epidemics.22 The remarkable upthrust of colonial population in the eighteenth century may have owed a good deal to the reduced smallpox death rate that inoculation brought about. White settlement along the frontier was assisted also by the fact that destruction of Indian populations by infectious diseases, of which smallpox remained the most formidable, continued unabated. The ravages of smallpox among Indians may in fact have been assisted by deliberate efforts at germ warfare. In 1763, for instance, Lord Jeffrey Amherst ordered that blankets infected with smallpox be distributed among enemy tribes, and the order was acted on. Whether the result was as expected seems not recorded.23

  In Spanish America, on the other hand, official efforts to protect Indians against smallpox waited only until an approved method of prophylaxis against the disease came to be recognized in Spain itself. This followed swiftly on the discovery of vaccination by Edward Jenner, an alert English country doctor, who published his results to the world in 1798. He had noticed that milkmaids seemed never to suffer from smallpox and surmised that they instead contracted cowpox from the animals they tended. Experiment with inoculation of human patients with cowpox showed that immunity to human smallpox did indeed result; and the dangers from cowpox for humans was negligible. Thus the main objection which had previously hampered the acceptance of inoculation with the smallpox itself was removed: and the value of the new method of “vaccination” came swiftly to be recognized in all of Europe.

  As a result, in 1803, a mere five years after Jenner’s book appeared, a medical mission from Spain arrived in Mexico to instruct local doctors in the new technique. By the time the mission departed for the Philippines (1807) to repeat the performance in that distant outpost of Spanish power, the practice of vaccination had been established among New World doctors. Thereafter, insofar as medical services reached the Indian communities the terrors of one of the principal killers that had so long ravaged Amerindian populations under Spanish rule must have diminished.24

  Elsewhere in Christian Europe, control of smallpox through deliberate medical action seems to have conformed rather to the French than to the English pattern, i.e., it became effective only shortly before 1800. Thus Catherine the Great introduced inoculation into Russia in 1768 by importing an English doctor to immunize herself and the Crown Prince; but only the court benefited from the Englishman’s expertise. In 1775, after Louis XV’s death from the disease, Frederick II of Prussia introduced inoculation into his kingdom, and characteristically did so by having the technique taught to doctors in the provinces, not just at court. It was, however, only when entire armies began to be immunized by command from the top that the practice really penetrated the lower social orders of continental Europe. In 1776, George Washington ordered inoculation for all the soldiers of his army; in 1805 Napoleon commanded that the improved vaccination method be used by all under his command.25 Effective prophylaxis against smallpox in Europe was thus a byproduct of the Napoleonic wars; and the extraordinary population growth that set the nineteenth century apart from all its predecessors in Europe’s history was in substantial part a consequence of the effective containment of this long-standing scourge of civilized human communities.

  In Turkey, however, smallpox inoculation had been practiced, at least in some milieux, earlier than anywhere else in Europe. It was, in fact, from Turkey that smallpox inoculation reached England, having been introduced to London in 1721, along with other oriental exotica like bloomers and the fez, by Lady Mary Wordey Montagu, wife of a returned ambassador to the Porte.26 A pair of Greek doctors in Constantinople, who had achieved familiarity with western medicine at the famous medical school of Padua, served as go-betweens. They transmitted information about the folk practice of Turkey to the learned community of Europe by writing a pair of pamphlets on the subject that were widely reproduced in England and elsewhere. According to their report, it was generally believed in Constantinople that the practice of inoculation had long been familiar among Greek peasant women of the Morea and Thessaly.

  Indeed, smallpox inoculation seems to have been known and practiced at a folk level throughout Arabia, North Africa, Persia, and India.27 Reports of a more elaborate Chinese method, involving the insertion of a suitable infected swab of cotton inside the patient’s nostril, reached London in 1700.28 Chinese texts assert that this practice had been introduced into China at the beginning of the eleventh century by a wandering wise man come from the Indian borderland. Subse-quently it is said to have become very popular.29 It therefore seems probable that deliberate inoculation of children with smallpox had been a folk practice in much
of Asia for centuries, long before it came to the attention of European doctors and penetrated the repertory of their officially approved techniques in the course of the eighteenth century.30

  Since the practice was so old and widespread at a folk level, why was it that the European medical profession and learned community picked up the practice of inoculation only in the eighteenth century, and why did this notable improvement in medical practice take place in England rather than elsewhere?

  One factor, surely, was accidental. Mary Wortley Montagu’s interest in inoculation was provoked by the fact that her own fair face had been scarred by smallpox that struck only after she had become an established hostess and lady of fashion. But London’s alert response to her news from Turkey depended on the fact that smallpox deaths among the reigning families of Europe twice affected British public life in important ways during the first decades of the eighteenth century. In 1700 Queen Anne’s son and sole surviving direct heir died of smallpox, thus opening afresh the question of succession to the English throne. Scarcely had the union of England and Scotland and the Hanoverian succession been agreed upon than another smallpox death in 1711, this time in the imperial Hapsburg house, disastrously disrupted plans agreed upon among the powers allied against France in the war of the Spanish succession. These two events, coming so close upon one another, and in both instances sharply altering the course of British political history, alerted the ruling classes of the British Isles to the dangers of smallpox. This set the stage for systematic inquiry by members of the Royal Society for ways of forestalling unexpected adult deaths from the disease, and prepared the ground for the positive and thoroughly scientific reaction to Lady Mary Wortley Montagu’s initiative among London’s medical and court circles.31

  Personal and political accidents, scientific and professional organization, and a systematically expanded network of communication among men of learning all came together therefore in the course of the eighteenth century to bring a sharp reduction of smallpox death tolls within the power of European doctors. Organized medicine thereby began for the first time to contribute to population growth in a statistically significant fashion. Even if, as seems probable, smallpox inoculation had been demographically significant in China and other parts of Asia for centuries before 1700, it had been a matter of folk practice analogous to the innumerable other customs and rules of hygiene that human beings had everywhere worked out and justified to themselves by a variety of naive and ingenious myths.

  Near Eastern folkways, as a matter of fact, had encrusted the simple practice of smallpox inoculation with a full complement of myth and ritual by the time learned Europeans first investigated the matter. The person to be inoculated was viewed as “buying” the disease, and to make the transaction effective, had to give ritual gifts to the person who performed the inoculation. The inoculation was made between thumb and forefinger so that the resulting pockmark showed quite conspicuously, and identified the receiver as a sort of initiate ever after. The entire ritual looked like an adaptation of commercial customs; and a priori one may believe that spread of inoculation at a folk level could most readily have occurred via carvan personnel, for whom protection against smallpox was an obvious advantage. Wherever the practice first developed, one may easily suppose that caravan traders heard of it, tried it, and thereafter propagated it as folk practice throughout the parts of Eurasia and Africa where caravan traffic constituted the main form of long-distance trade.32

  As we saw in Chapter V, bubonic plague followed precisely the same routes in disseminating itself among human populations of Asia and eastern Europe in modern times. There may, in fact, have been a sort of demographic balancing act in the way plague exposure and an effective prophylaxis against smallpox spread along the same paths at nearly the same time. When, however, the technique of inoculation reached western Europe, where plague had already disappeared, the effect was obviously to reinforce possibilities of population growth as never before.

  Only in Europe was the medical profession well enough organized to spread news of new methods rapidly among rank-and-file practitioners, who were then able to inoculate on a massive scale as soon as local demand for such protection developed. Hence, once the technique came to doctors’ attention, inoculation against smallpox remained part of professional medical practice in Europe. This in turn meant that systematic efforts to discover and test improvements could and did take place from the start. The spectacular upshot was the discovery and acceptance of vaccination within less than a century.

  Even more spectacular was the speed with which the tech- nique of vaccination spread throughout the world on the strength of the existing European medical communications network. Thus, for example, a doctor in backwoods Kentucky had vaccinated some five hundred persons in the small town of Lexington by 1803; Russian doctors began vaccinating natives in Khiatka, on the Chinese border, in 1805, and in the same year a Portuguese merchant in Macao brought vaccine from the Philippines to meet the crisis of a large-scale outbreak of smallpox in South China.33, 34 More remarkable still: in 1812 Tartar merchants in Bukhara and Samarcand (then still beyond Russia’s borders) distributed pamphlets describing Jenner’s method of vaccination which had been printed at Kazan in Arabic and Chagatay Turkish, presumably as part of the Russian government’s systematic effort to spread the technique throughout their Asian territories.35

  Two observations about the connection between disease history and the more general patterns of Europe’s development seem appropriate at this point. First, the rise of Great Britain in comparison with France in the course of the eighteenth century depended, among other things, on the remarkable population growth that set in earlier and continued longer in Britain than it did in France. Political institutions, the distribution of coal and iron ore, social structures, values, and individual inventiveness all played a role in defining the over-all result: but in light of what can now be said about the retreat of plague, malaria, and other infectious diseases from the English countryside, together with England’s head start in the deliberate control of smallpox, it seems clear enough that divergent disease experiences in the two countries had much to do with their divergent population histories. Shifting patterns of disease therefore take a place as one of the determinants of European and world history in the eighteenth century, for the rise of the British empire and the temporary eclipse of France overseas after 1763 must certainly rank as a critical turning point in the history of America, Africa, and Asia, as well as of Europe.

  Secondly, although in the eighteenth century the major triumphs of scientific medicine lay still in the future, it does not seem absurd to suggest that decreasing significance of epidemic disease, partly due to medical advances but mostly due to ecological adjustments of which men were entirely unaware, constituted an essential background for the popularization of “enlightened” philosophical and social views. A world where sudden and unexpected death remains a real and dreaded possibility in everyone’s life experience makes the idea that the universe is a great machine whose motions are regular, understandable and even predictable, seem grossly inadequate to account for observed reality. Epidemic disease, after all, strikes erratically as well as unpredictably, and can never be dismissed as insignificant by those exposed to it. Before the findings of the astronomers and mathematicians of the seventeenth century could become a basis for a popularized world view, therefore, epidemic disease had also to relax its dominion over human minds and bodies. The retreat of plague and malaria and the containment of smallpox were thus essential preparations for the propagation of deistic opinions of the kind that became fashionable in advanced circles in the eighteenth century.

  A world in which lethal infectious disease seldom seized a person suddenly in the prime of life no longer stood so much in need of belief in Divine Providence to explain such deaths. Moreover, as in other orthogenetic evolutionary situations, newfangled mechanistic world views sustained the search for more effective methods for coping with disease, and made th
e medical profession increasingly systematic in testing new treatments empirically. Real improvements resulted; and the thought that human intelligence and skill could improve life not only in mechanical but also in health matters became increasingly plausible.

  There seems therefore a clear correlation between Europe’s shifting encounter with disease and the phases of that continent’s cultural and political history. Between 1494 and 1648 the stresses upon older cultural traditions were especially acute because Europeans had to adjust to the initial impact of transoceanic movement of men, goods, ideas, and diseases—all at once. The political and ideological storms of the Reformation and wars of religion manifested these strains. Only as the first shocks wore off, including, significantly, the decay of epidemic disease and its replacement by more predictable, less damaging patterns of infection, was it possible for the relaxed political and cultural style of life we call the Old Regime to establish itself. Obviously, the changing incidence of disease was only one, and not the most conspicuous, factor in bringing about such changes. Yet because it has usually been completely overlooked by historians, the experience of disease and of shifting encounters with lethal infections, seems worth emphasizing here.

  In all ecological relationships, a significant breakthrough for one organism or group of organisms quickly creates new stresses in the system. These stresses usually are such as first to diminish and then contain the original disturbance. So it was with Australian rabbits, 1856–1960, and so it was in northwestern Europe between 1750 and 1850, as the industrial revolution began to gather headway. Living conditions in new industrial towns were, and long remained, notoriously un-healthful. On the other hand, improvements in transportation allowed increasingly efficient patterns of food distribution to fend off local famines. Food preservation was almost equally important. Canning, for instance, was invented in 1809 in response to an offer of a handsome reward by the French government; and Napoleon’s armies pioneered its large-scale use.36