in ancient and modern times, not without favourable results for science; nay, more matured views excited an eager desire to become acquainted with similar or still greater visitations among the ancients; but as later ages have always been fond of referring to Grecian antiquity, the learned of those times, from a partial and meagre predilection, were contented with the descriptions of Thucydides, even where nature had revealed, in infinite diversity, the workings of her powers.
These researches, if indeed they deserved that name, were never scientific or comprehensive. They never seized but upon a part, and no sooner had the mortality ceased, than the scarcely awakened zeal relapsed into its former indifference to the interesting phenomena of nature, in the same way as abstemiousness, which had ever been practised during epidemics, only as a constrained virtue, gave place, as soon as the danger was over, to unbridled indulgence. This inconstancy might almost bring to our mind the pious Byzantines who, on the shock of an earthquake, in 529, which appeared as the prognostic of the great epidemic, prostrated themselves before their altars by thousands, and sought to excel each other in Christian self-denial and benevolence; but no sooner did they feel the ground firm beneath their feet, than they again abandoned themselves, without remorse, to all the vices of the metropolis. May I be pardoned for this comparison of scientific zeal with other human excitements? Alas! even this is a virtue which few practise for its own sake, and which, with the multitude, stands quite as much in need as any other, of the incentives of fear and reward.
But we are constrained to acknowledge that among our medical predecessors, these incentives were scarcely ever sufficiently powerful to induce them to leave us circumstantial and scientific accounts of contemporary epidemics, which, nevertheless, have, even in historical times, afflicted, in almost numberless visitations, the whole human race. Still less did it occur to them to take a more exalted stand, whence they could comprehend at one view, these stupendous phenomena of organic collective life, wherein the whole spirit of humanity powerfully and wonderfully moves, and thus regard them as one whole, in which higher laws of nature, uniting together the utmost diversity of individual parts, might be anticipated or perceived.
Here a wide, and almost unfathomable chasm occurs in the science of medicine, which, in this age of mature judgment and multifarious learning, cannot, as formerly, be overlooked. History alone can fill it up; she alone can give to the doctrine of diseases that importance without which its application is limited to occurrences of the moment; whereas the development of the phenomena of life, during extensive periods, is no less a problem of research for the philosopher, who makes the boundless science of nature his study, than the revolutions of the planet on which we move. In this region of inquiry the very stones have a language, and the inscriptions are yet legible which, before the creation of man, were engraved by organic life, in wondrous forms on eternal tablets. Exalted ideas of the monuments of primæval antiquity are here excited, and the forms of the antemundane ways and creations of nature are conjured up from the inmost bosom of the earth, in order to throw their bright beaming light upon the surface of the present.
Medicine extends not so far. The remains of animals make us indeed acquainted, even now, with diseases to which the brute creation was subject long ere the waters overflowed, and the mountains sunk; but the investigation which is our more immediate object, scarcely reaches to the beginning of human culture. Records of remote and of proximate eras, lie before us in rich abundance. They speak of the deviations and destructions of human life, of exterminated and newly-formed nations; they lay before us stupendous facts, which we are called upon to recognise and expound in order to solve this exalted problem. If physicians cannot boast of having unrolled these records with the avidity of true explorers of Nature, they may find some excuse in the nature of the inquiry—for the characters are dead, and the spirits of which they are the magic symbols, manifest themselves only to him who knows how to adjure them. Epidemics leave no corporeal traces; whence their history is perhaps more intellectual than the science of the Geologist, who, on his side, possesses the advantage of treating on subjects which strike the senses, and are therefore more attractive,—such as the impressions of plants no longer extant, and the skeletons of lost races of animals. This, however, does not entirely exculpate us from the charge of neglecting our science, in a quarter where the most important facts are to be unveiled. It is high time to make up for what has been left unaccomplished, if we would not remain idle and mean-spirited in the rear of other naturalists.
I was animated by these and similar reflections, and excited too by passing events, when I undertook to write the history of the “Black Death.” With some anxiety, I sent this book into the world, for it was scarcely to be expected that it would be everywhere received with indulgence, since it belonged to an hitherto unknown department of historical research, the utility of which might not be obvious in our practical times. Yet I soon received encouragement, not only from learned friends, but also from other men of distinguished merit, on whose judgment I placed great reliance; and thus I was led to hope that it was not in vain, and without some advantage to science, that I had unveiled the dismal picture of a long departed age.
This work I have followed up by a treatise on a nervous disorder, which, for the first time, appeared in the same century, as an epidemic, with symptoms that can be accounted for only by the spirit of the Middle Ages—symptoms which, in the manner of the diffusion of the disease among thousands of people, and of its propagation for more than two centuries, exercised a demoniacal influence over the human race, yet in close, though uncongenial alliance, with kindlier feelings. I have prepared materials for various other subjects, so far as the resources at my disposal extend, and I may hope, if circumstances prove favourable, to complete by degrees, the history of a more extensive series of Epidemics on the same plan as the “Black Death,” and the “Dancing Mania.”
Amid the accumulated materials which past ages afford, the powers and the life of one individual, even with the aid of previous study, are insufficient to complete a comprehensive history of Epidemics. The zealous activity of many must be exerted if we would speedily possess a work which is so much wanted in order that we may not encounter new epidemics with culpable ignorance of analogous phenomena. How often has it appeared on the breaking out of epidemics, as if the experience of so many centuries had been accumulated in vain. Men gazed at the phenomena with astonishment, and even before they had a just perception of their nature, pronounced their opinions, which, as they were divided into strongly opposed parties, they defended with all the ardour of zealots, wholly unconscious of the majesty of all-governing nature. In the descriptive branches of natural history, a person would infallibly expose himself to the severest censure, who should attempt to describe some hitherto unknown natural production, whether animal or vegetable, if he were ignorant of the allied genera and species, and perhaps neither a botanist nor zoologist; yet an analogous ignorance of epidemics, in those who nevertheless discussed their nature, but too frequently occurred, and men were insensible to the justest reproof. Thus it has ever been, and for this reason we cannot apply to ourselves in this department, the significant words of Bacon, that we are the ancients, and our forefathers the moderns, for we are equally remote, with them, from a scientific and comprehensive knowledge of epidemics. This might, and ought to be otherwise, in an age which, in other respects, may, with justice, boast of a rich diversity of knowledge, and of a rapid progress in the natural sciences.
If in the form of an address to the physicians of Germany, I express the wish to see such a melancholy state of things remedied, the nature of the subject requires that, with the exception of the still prevailing Cholera, remarkable universal epidemics should be selected for investigation. They form the grand epochs, according to which those epidemics which are less extensive, but not, on that account, less worthy of observation, naturally range themselves. Far be it from me to recommend any fixed series, or even the plan and method to be pursued in treating the subject. It would, perhaps, be, on the whole, most advantageous, if my honoured Colleagues, who attend to this request, were to commence with those epidemics for which they possess complete materials, and that entirely according to their own plan, without adopting any model for imitation, for in this manner simple historical truth will be best elicited. Should it, however, be found impracticable to furnish historical descriptions of entire epidemics, a task often attended with difficulties, interesting fragments of all kinds, for which there are rich treasures in MSS. and scarce works in various places, would be no less welcome and useful towards the great object of preparing a collective history of epidemics.