TODAY, GLANDERS is a disease rarely heard of in Western Europe, Britain, and North America; but a hundred years ago the annual total of cases of glanders in the horse, published by the Board of Agriculture, exceeded 2,000,1 and British veterinarians were all too familiar with the disease. Moreover, transmission to man took place with distressing regularity, and the outcome was nearly always fatal.2 In 1908, William Hunting, Chief Veterinary Inspector to the London County Council, wrote: "Glanders in man is such a loathsome and fatal disease as to deserve more attention than it receives. ... If the medical profession called for the suppression of glanders as loudly as they did for the extermination of rabies, prevention in all animals would be accelerated. Hydrophobia in man ceased when we had stamped out rabies in dogs, and glanders in man will only cease when the disease no longer exists among horses".3 Historically, the juxtaposition with rabies is apt. Over the centuries the number of animals of the equine species, and of men, whether infected naturally or in the laboratory, killed by glanders have probably equalled or even outweighed those who have succumbed to rabies. In times of war, from the Middle Ages onwards and as late as World War I,4 losses of horses through glanders in the armed forces of all nations must have been always an important and influential factor.' Yet in historical terms the literature on rabies is copious, while glanders has remained very much a neglected subject. Whereas the drama and unpredictability surrounding the clinical manifestations of rabies have frequently attracted the attention of medical and lay historians alike, glanders has remained ignored by most historians even in the context of the

DuRING THE last quarter of the nineteenth century bacteriology emerged as a separate discipline. A number of pathogenic bacteria were isolated and described, and it proved possible to grow them in culture on artifical media. At the same time, there were diseases which were being studied in great detail, but for which no infectious agent could be found.One such example was rabies. Although the number of victims was limited, its manifestations and manner of spread were striking and caused much public concern. When Pasteur achieved the development of a vaccine, and saved the life of a young boy who would otherwise certainly have succumbed to the disease, the emotional impact and the professional response were considerable. Yet, in spite of much painstaking work, Pasteur failed to isolate a causal organism. All the evidence suggests that although Pasteur may have conceived of a causal agent so small that it eluded detection by the light microscope, he did not suspect that it differed essentially from the pathogenic micro-organisms so far observed.Then, in the last decade of the century, work on two very different conditions yielded unexpected results. In 1892, Ivanovski, a young Russian botanist, published his report' of a study of the mosaic disease of the tobacco plant, carried out on tobacco plantations in different parts of Russia, and in the laboratories of the Academy of Sciences in St. Petersburg. Ivanovski found that when he passed the sap of infected tobacco plants through bacteria-proof filters, the clear filtrate remained infectious when inoculated into healthy plants. This did not surprise him, since he suspected the presence of a bacterial toxin and saw the result as support for his theory. The Russian journal in which the paper was published does not appear to have had a wide distribution outside Russia at the time,2 and Ivanovski's results passed largely unnoticed.

WHEN wRmUhBs of medical texts wish to remind their readers that virus disease is nothing new, they turn to the records of smallpox and of rabies. From antiquity, and through the centuries, the impact of smallpox on social and political history through the extent and severity of epidemics, and the high rate of mortality, has been considerable and equalled among the infectious diseases only by bubonic plague.' Rabies on the other hand never claimed large numbers of victims even in epidemic situations. In one outbreak which caused concern in nineteenth-century Lancashire, the total number of deaths in the year 1866 was reported to be thirty-six, and of this Fleming wrote: ".. . West Lancashire appeared to have become a centre from which it spread in various directions, until it became disseminated, and had attained the dimensions of a serious epizooty-formidable alike to mankind, as well as to the other domesticated animals".2 In a contemporary outbreak in Denmark, the number of cases totalled 227 dogs, nine cattle, six horses, five sheep, and a few cats. There were four human fatalities.3 Compared to the numerous shorter and sharper outbreaks of bubonic plague and smallpox in Europe during the centuries when they held sway, and when there were frequently tens, and sometimes hundreds, of thousands of deaths in a few months,4 the figures for rabies appear almost insignificantly low. Nevertheless, rabies has captured the imagination of writers and thinkers from the time of antiquity. The alarming symptoms in man and dog alike, the prolonged suffering of the victims and the inevitable fatality of the established clinical disease: the distressing syndrome as a whole has meant that outbreaks of the disease have been meticulously recorded out of all proportion to the slight numbers of victims claimed in comparison with the major scourges of mankind. The manner of its transmission has ensured for rabies a unique position in the annals of infectious disease. The detailed descriptions *This work was made possible by a grant from the Wellcome Trust.

Bacteriology became an established academic discipline with the discoveries and the subsequent classification of a number of pathogenic bacteria during the latter half of the nineteenth century. The first attempt to trace the historical background to this new development appeared as early as 1887 as a series of lectures given by Friedrich Loffler and dedicated to his mentor Robert Koch.' LoMffer paid only scant attention to developments prior to 1800, although he was more appreciative of the work of Athanasius Kircher (160240) than many other commentators,2 and devoted several pages to Leeuwenhoek's discoveries. His interest in the eighteenth century was limited to a brief mention of works inspired by the plague in Toulon, and an even briefer reference to Lancisi's views concerning malaria, in addition to a paragraph on Plenciz' theories of contagium animatum and their relationship to Leeuwenhoek's observations.3 Loffler's historical essaysand several later works4-contain no mention of the diseases specific to cattle which played havoc in Europe at a time when veterinary science hardly existed.5 Medical authorities were forced to take a long, hard look at these diseasesbovine pleuropneumonia, foot-and-mouth disease, and, above all, rinderpest.' In the process, they learned much about the control of epizootics and

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