Читать книгу The History of Epidemics in the Middle Ages - J. F. C. Hecker - Страница 13

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If we now turn to the medical talent which encountered the “Great Mortality,” the middle ages must stand excused, since even the moderns are of opinion that the art of medicine is not able to cope with the Oriental plague, and can afford deliverance from it only under particularly favourable circumstances159. We must bear in mind also, that human science and art appear particularly weak in great pestilences, because they have to contend with the powers of nature, of which they have no knowledge; and which, if they had been, or could be comprehended in their collective effects, would remain uncontrollable by them, principally on account of the disordered condition of human society. Moreover, every new plague has its peculiarities, which are the less easily discovered on first view, because, during its ravages, fear and consternation humble the proud spirit.

The physicians of the 14th century, during the Black Death, did what human intellect could do in the actual condition of the healing art; and their knowledge of the disease was by no means despicable. They, like the rest of mankind, have indulged in prejudices, and defended them, perhaps, with too much obstinacy; some of these, however, were founded on the mode of thinking of the age, and passed current in those days, as established truths: others continue to exist to the present hour.

Their successors in the 19th century, ought not therefore to vaunt too highly the pre-eminence of their knowledge, for they too will be subjected to the severe judgment of posterity—they too, will, with reason, be accused of human weakness and want of foresight.

The medical faculty of Paris, the most celebrated of the 14th century, were commissioned to deliver their opinion on the causes of the Black Plague, and to furnish some appropriate regulations with regard to living, during its prevalence. This document is sufficiently remarkable to find a place here.

“We, the Members of the College of Physicians of Paris, have, after mature consideration and consultation on the present mortality, collected the advice of our old masters in the art, and intend to make known the causes of this pestilence, more clearly than could be done according to the rules and principles of astrology and natural science; we, therefore, declare as follows:—

“It is known that in India, and the vicinity of the Great Sea, the constellations which combated the rays of the sun, and the warmth of the heavenly fire, exerted their power especially against that sea, and struggled violently with its waters. (Hence, vapours often originate which envelope the sun, and convert his light into darkness.) These vapours alternately rose and fell for twenty-eight days; but at last, sun and fire acted so powerfully upon the sea, that they attracted a great portion of it to themselves, and the waters of the ocean arose in the form of vapour; thereby the waters were, in some parts, so corrupted, that the fish which they contained, died. These corrupted waters, however, the heat of the sun could not consume, neither could other wholesome water, hail or snow, and dew, originate therefrom. On the contrary, this vapour spread itself through the air in many places on the earth, and enveloped them in fog.

“Such was the case all over Arabia, in a part of India; in Crete; in the plains and valleys of Macedonia; in Hungary, Albania and Sicily. Should the same thing occur in Sardinia, not a man will be left alive; and the like will continue, so long as the sun remains in the sign of Leo, on all the islands and adjoining countries to which this corrupted sea-wind extends, or has already extended from India. If the inhabitants of those parts do not employ and adhere to the following, or similar means and precepts, we announce to them inevitable death—except the grace of Christ preserve their lives.

“We are of opinion, that the constellations, with the aid of Nature, strive, by virtue of their divine might, to protect and heal the human race; and to this end, in union with the rays of the sun, acting through the power of fire, endeavour to break through the mist. Accordingly, within the next ten days, and until the 17th of the ensuing month of July, this mist will be converted into a stinking deleterious rain, whereby the air will be much purified. Now, as soon as this rain shall announce itself, by thunder or hail, every one of you should protect himself from the air; and, as well before as after the rain, kindle a large fire of vine-wood, green laurel, or other green wood; wormwood and chamomile should also be burnt in great quantity in the market-places, in other densely inhabited localities, and in the houses. Until the earth is again completely dry, and for three days afterwards, no one ought to go abroad in the fields. During this time the diet should be simple, and people should be cautious in avoiding exposure in the cool of the evening, at night, and in the morning. Poultry and water-fowl, young pork, old beef, and fat meat, in general, should not be eaten; but on the contrary, meat of a proper age, of a warm and dry, but on no account of a heating and exciting nature. Broth should be taken, seasoned with ground pepper, ginger and cloves, especially by those who are accustomed to live temperately, and are yet choice in their diet. Sleep in the day-time is detrimental; it should be taken at night until sunrise, or somewhat longer. At breakfast, one should drink little; supper should be taken an hour before sunset, when more may be drunk than in the morning. Clear light wine, mixed with a fifth or sixth part of water, should be used as a beverage. Dried or fresh fruits, with wine, are not injurious; but highly so without it. Beet-root and other vegetables, whether eaten pickled or fresh, are hurtful; on the contrary, spicy pot-herbs, as sage or rosemary, are wholesome. Cold, moist, watery food is in general prejudicial. Going out at night, and even until three o’clock in the morning, is dangerous, on account of the dew. Only small river fish should be used. Too much exercise is hurtful. The body should be kept warmer than usual, and thus protected from moisture and cold. Rain-water must not be employed in cooking, and every one should guard against exposure to wet weather. If it rain, a little fine treacle should be taken after dinner. Fat people should not sit in the sunshine. Good clear wine should be selected and drunk often, but in small quantities, by day. Olive oil as an article of food, is fatal. Equally injurious are fasting and excessive abstemiousness, anxiety of mind, anger, and immoderate drinking. Young people, in autumn especially, must abstain from all these things, if they do not wish to run a risk of dying of dysentery. In order to keep the body properly open, an enema, or some other simple means, should be employed, when necessary. Bathing is injurious. Men must preserve chastity as they value their lives. Every one should impress this on his recollection, but especially those who reside on the coast, or upon an island into which the noxious wind has penetrated.”160

On what occasion these strange precepts were delivered can no longer be ascertained, even if it were an object to know it. It must be acknowledged, however, that they do not redound to the credit either of the faculty of Paris, or of the 14th century in general. This famous faculty found themselves under the painful necessity of being wise at command, and of firing a point blank shot of erudition at an enemy who enveloped himself in a dark mist, of the nature of which they had no conception. In concealing their ignorance by authoritative assertions, they suffered themselves, therefore, to be misled; and while endeavouring to appear to the world with eclat, only betrayed to the intelligent their lamentable weakness. Now some might suppose, that in the condition of the sciences of the 14th century, no intelligent physicians existed; but this is altogether at variance with the laws of human advancement, and is contradicted by history. The real knowledge of an age is shewn only in the archives of its literature. Here alone the genius of truth speaks audibly:—here alone men of talent deposit the results of their experience and reflection, without vanity or a selfish object. There is no ground for believing that, in the 14th century, men of this kind were publicly questioned regarding their views; and it is, therefore, the more necessary that impartial history should take up their cause and do justice to their merits.

The first notice on this subject is due to a very celebrated teacher in Perugia, Gentilis of Foligno, who, on the 18th of June, 1348, fell a sacrifice to the plague, in the faithful discharge of his duty161. Attached to Arabian doctrines, and to the universally respected Galen, he, in common with all his contemporaries, believed in a putrid corruption of the blood in the lungs and in the heart, which was occasioned by the pestilential atmosphere, and was forthwith communicated to the whole body. He thought, therefore, that every thing depended upon a sufficient purification of the air, by means of large blazing fires of odoriferous wood, in the vicinity of the healthy, as well as of the sick, and also upon an appropriate manner of living; so that the putridity might not overpower the diseased. In conformity with notions derived from the ancients, he depended upon bleeding and purging, at the commencement of the attack, for the purpose of purification; ordered the healthy to wash themselves frequently with vinegar or wine, to sprinkle their dwellings with vinegar, and to smell often to camphor, or other volatile substances. Hereupon he gave, after the Arabian fashion, detailed rules, with an abundance of different medicines, of whose healing powers wonderful things were believed. He laid little stress upon super-lunar influences, so far as respected the malady itself; on which account, he did not enter into the great controversies of the astrologers, but always kept in view, as an object of medical attention, the corruption of the blood in the lungs and heart. He believed in a progressive infection from country to country, according to the notions of the present day; and the contagious power of the disease, even in the vicinity of those affected by plague, was, in his opinion, beyond all doubt162. On this point, intelligent contemporaries were all agreed; and in truth, it required no great genius to be convinced of so palpable a fact. Besides, correct notions of contagion have descended from remote antiquity, and were maintained unchanged in the 14th century163. So far back as the age of Plato, a knowledge of the contagious power of malignant inflammations of the eye, of which also no physician of the middle ages entertained a doubt164, was general among the people165; yet, in modern times, surgeons have filled volumes with partial controversies on this subject. The whole language of antiquity has adapted itself to the notions of the people, respecting the contagion of pestilential diseases; and their terms were, beyond comparison, more expressive than those in use among the moderns166.

Arrangements for the protection of the healthy against contagious diseases, the necessity of which is shewn from these notions, were regarded by the ancients as useful; and by many, whose circumstances permitted it, were carried into effect in their houses. Even a total separation of the sick from the healthy, that indispensable means of protection against infection by contact, was proposed by physicians of the 2nd century after Christ, in order to check the spreading of leprosy. But it was decidedly opposed, because, as it was alleged, the healing art ought not to be guilty of such harshness167. This mildness of the ancients, in whose manner of thinking inhumanity was so often and so undisguisedly conspicuous, might excite surprise, if it were any thing more than apparent. The true ground of the neglect of public protection against pestilential diseases, lay in the general notion and constitution of human society,—it lay in the disregard of human life, of which the great nations of antiquity have given proofs in every page of their history. Let it not be supposed that they wanted knowledge respecting the propagation of contagious diseases. On the contrary, they were as well informed on this subject as the moderns; but this was shewn where individual property, not where human life, on the grand scale, was to be protected. Hence the ancients made a general practice of arresting the progress of murrains among cattle, by a separation of the diseased from the healthy. Their herds alone enjoyed that protection which they held it impracticable to extend to human society, because they had no wish to do so168. That the governments in the 14th century, were not yet so far advanced, as to put into practice general regulations for checking the plague, needs no especial proof. Physicians could, therefore, only advise public purifications of the air by means of large fires, as had often been practised in ancient times; and they were obliged to leave it to individual families, either to seek safety in flight, or to shut themselves up in their dwellings169, a method which answers in common plagues, but which here afforded no complete security, because such was the fury of the disease when it was at its height, that the atmosphere of whole cities was penetrated by the infection.

Of the astral influence which was considered to have originated the “Great Mortality,” physicians and learned men were as completely convinced as of the fact of its reality. A grand conjunction of the three superior planets, Saturn, Jupiter and Mars, in the sign of Aquarius, which took place, according to Guy de Chauliac, on the 24th of March, 1345, was generally received as its principal cause. In fixing the day, this physician, who was deeply versed in astrology, did not agree with others; whereupon there arose various disputations, of weight in that age, but of none in ours; people, however, agreed in this—that conjunctions of the planets infallibly prognosticated great events; great revolutions of kingdoms, new prophets, destructive plagues, and other occurrences which bring distress and horror on mankind. No medical author of the 14th and 15th centuries omits an opportunity of representing them as among the general prognostics of great plagues; nor can we, for our parts, regard the astrology of the middle ages, as a mere offspring of superstition. It has not only, in common with all ideas which inspire and guide mankind, a high historical importance, entirely independent of its error or truth—for the influence of both is equally powerful—but there are also contained in it, as in alchymy, grand thoughts of antiquity, of which modern natural philosophy is so little ashamed that she claims them as her property. Foremost among these, is the idea of the general life which diffuses itself throughout the whole universe, expressed by the greatest Greek sages, and transmitted to the middle ages, through the new Platonic natural philosophy. To this impression of an universal organism, the assumption of a reciprocal influence of terrestrial bodies could not be foreign170, nor did this cease to correspond with a higher view of nature, until astrologers overstepped the limits of human knowledge with frivolous and mystical calculations.

Guy de Chauliac, considers the influence of the conjunction, which was held to be all-potent, as the chief general cause of the Black Plague; and the diseased state of bodies, the corruption of the fluids, debility, obstruction, and so forth, as the especial subordinate causes171. By these, according to his opinion, the quality of the air, and of the other elements, was so altered, that they set poisonous fluids in motion towards the inward parts of the body, in the same manner as the magnet attracts iron; whence there arose in the commencement fever and the spitting of blood; afterwards, however, a deposition in the form of glandular swellings and inflammatory boils. Herein the notion of an epidemic constitution was set forth clearly, and conformably to the spirit of the age. Of contagion, Guy de Chauliac was completely convinced. He sought to protect himself against it by the usual means172; and it was probably he who advised Pope Clement VI. to shut himself up while the plague lasted. The preservation of this pope’s life, however, was most beneficial to the city of Avignon, for he loaded the poor with judicious acts of kindness, took care to have proper attendants provided, and paid physicians himself to afford assistance wherever human aid could avail—an advantage which, perhaps, no other city enjoyed173. Nor was the treatment of plague-patients in Avignon by any means objectionable; for, after the usual depletions by bleeding and aperients, where circumstances required them, they endeavoured to bring the buboes to suppuration; they made incisions into the inflammatory boils, or burned them with a red-hot iron, a practice which at all times proves salutary, and in the Black Plague saved many lives. In this city, the Jews, who lived in a state of the greatest filth, were most severely visited, as also the Spaniards, whom Chalin accuses of great intemperance174.

Still more distinct notions on the causes of the plague were stated to his contemporaries in the 14th century, by Galeazzo di Santa Sofia, a learned man, a native of Padua, who likewise treated plague-patients at Vienna175, though in what year is undetermined. He distinguishes carefully pestilence from epidemy and endemy. The common notion of the two first accords exactly with that of an epidemic constitution, for both consist, according to him, in an unknown change or corruption of the air; with this difference, that pestilence calls forth diseases of different kinds; epidemy, on the contrary, always the same disease. As an example of an epidemy, he adduces a cough (influenza) which was observed in all climates at the same time, without perceptible cause; but he recognised the approach of a pestilence, independently of unusual natural phenomena, by the more frequent occurrence of various kinds of fever, to which the modern physicians would assign a nervous and putrid character. The endemy originates, according to him, only in local telluric changes—in deleterious influences which develop themselves in the earth and in the water, without a corruption of the air. These notions were variously jumbled together in his time, like every thing which human understanding separates by too fine a line of limitation. The estimation of cosmical influences, however, in the epidemy and pestilence, is well worthy of commendation; and Santa Sofia, in this respect, not only agrees with the most intelligent persons of the 14th and 15th centuries, but he has also promulgated an opinion which must, even now, serve as a foundation for our scarcely commenced investigations into cosmical influences176. Pestilence and epidemy, consist not in alterations of the four primary qualities177, but in a corruption of the air, powerful, though quite immaterial, and not cognoscible by the senses:—(corruptio aëris non substantialis, sed qualitativa) in a disproportion of the imponderables in the atmosphere, as it would be expressed by the moderns178. The causes of the pestilence and epidemy are, first of all, astral influences, especially on occasion of planetary conjunctions; then extensive putrefaction of animal and vegetable bodies, and terrestrial corruptions (corruptio in terra); to which also, bad diet and want may contribute. Santa Sofia considers the putrefaction of locusts, that had perished in the sea, and were again thrown up, combined with astral and terrestrial influences, as the cause of the pestilence in the eventful year of the “Great Mortality.”

All the fevers which were called forth by the pestilence, are, according to him, of the putrid kind; for they originate principally from putridity of the heart’s blood, which inevitably follows the inhalation of infected air. The Oriental Plague is, sometimes, but by no means always, occasioned by pestilence (?), which imparts to it a character (qualitas occulta) hostile to human nature. It originates frequently from other causes, among which, this physician was aware that contagion was to be reckoned; and it deserves to be remarked, that he held epidemic small-pox and measles to be infallible forerunners of the plague, as do the physicians and people of the East179, at the present day.

In the exposition of his therapeutical views of the plague, a clearness of intellect is again shewn by Santa Sofia, which reflects credit on the age. It seemed to him to depend, 1st, on an evacuation of putrid matters, by purgatives and bleeding: yet he did not sanction the employment of these means indiscriminately, and without consideration; least of all where the condition of the blood was healthy. He also declared himself decidedly against bleeding ad deliquium (venæ sectio eradicativa). 2d, Strengthening of the heart and prevention of putrescence. 3d, Appropriate regimen. 4th, Improvement of the air. 5th, Appropriate treatment of tumid glands and inflammatory boils, with emollient, or even stimulating poultices (mustard, lily-bulbs), as well as with red-hot gold and iron. Lastly, 6th, Attention to prominent symptoms. The stores of the Arabian pharmacy, which he brought into action to meet all these indications, were indeed very considerable; it is to be observed, however, that, for the most part, gentle means were accumulated, which, in case of abuse, would do no harm; for the character of the Arabian system of medicine, whose principles were everywhere followed at this time, was mildness and caution. On this account too, we cannot believe that a very prolix treatise by Marsigli di Santa Sofia180, a contemporary relative of Galeazzo, on the prevention and treatment of plague, can have caused much harm, although, perhaps, even in the 14th century, an agreeable latitude and confident assertions respecting things which no mortal has investigated, or which it is quite a matter of indifference to distinguish, were considered as proofs of a valuable practical talent.

The agreement of contemporary and later writers, shews that the published views of the most celebrated physicians of the 14th century, were those generally adopted. Among these, Chalin de Vinario is the most experienced. Though devoted to astrology, still more than his distinguished contemporary, he acknowledges the great power of terrestrial influences, and expresses himself very sensibly on the indisputable doctrine of contagion, endeavouring thereby to apologize for many surgeons and physicians of his time, who neglected their duty181. He asserted boldly, and with truth, “that all epidemic diseases might become contagious182, and all fevers epidemic,” which attentive observers of all subsequent ages have confirmed.

He delivered his sentiments on blood-letting with sagacity, as an experienced physician; yet he was unable, as may be imagined, to moderate the desire for bleeding shewn by the ignorant monks. He was averse to draw blood from the veins of patients under fourteen years of age; but counteracted inflammatory excitement in them by cupping; and endeavoured to moderate the inflammation of the tumid glands by leeches183. Most of those who were bled, died; he therefore reserved this remedy for the plethoric; especially for the papal courtiers, and the hypocritical priests, whom he saw gratifying their sensual desires, and imitating Epicurus, whilst they pompously pretended to follow Christ184. He recommended burning the boils with a red-hot iron, only in the plague without fever, which occurred in single cases185; and was always ready to correct those over-hasty surgeons, who, with fire and violent remedies, did irremediable injury to their patients186. Michael Savonarola, professor in Ferrara (1462), reasoning on the susceptibility of the human frame to the influence of pestilential infection, as the cause of such various modifications of disease, expresses himself as a modern physician would on this point; and an adoption of the principle of contagion was the foundation of his definition of the plague187. No less worthy of observation are the views of the celebrated Valescus of Taranta, who, during the final visitation of the Black Death, in 1382, practised as a physician at Montpellier, and handed down to posterity what has been repeated in innumerable treatises on plague, which were written during the 15th and 16th centuries188.

Of all these notions and views regarding the plague, whose development we have represented, there are two especially, which are prominent in historical importance:—1st, The opinion of learned physicians, that the pestilence, or epidemic constitution, is the parent of various kinds of disease; that the plague sometimes, indeed, but by no means always, originates from it: that, to speak in the language of the moderns, the pestilence bears the same relation to contagion, that a predisposing cause does to an occasional cause: and 2dly, the universal conviction of the contagious power of that disease.

Contagion gradually attracted more notice: it was thought that in it, the most powerful occasional cause might be avoided; the possibility of protecting whole cities by separation, became gradually more evident; and so horrifying was the recollection of the eventful year of the “Great Mortality,” that before the close of the 14th century, ere the ill effects of the Black Plague had ceased, nations endeavoured to guard against the return of this enemy, by an earnest and effectual defence.

The first regulation which was issued for this purpose, originated with Viscount Bernabo, and is dated the 17th Jan. 1374. “Every plague-patient was to be taken out of the city into the fields, there to die or to recover. Those who attended upon a plague-patient, were to remain apart for ten days, before they again associated with any body. The priests were to examine the diseased, and point out to special commissioners the persons infected; under punishment of the confiscation of their goods, and of being burned alive. Whoever imported the plague, the state condemned his goods to confiscation. Finally, none except those who were appointed for that purpose, were to attend plague-patients, under penalty of death and confiscation189.”

These orders, in correspondence with the spirit of the 14th century, are sufficiently decided to indicate a recollection of the good effects of confinement, and of keeping at a distance those suspected of having plague. It was said that Milan itself, by a rigorous barricado of three houses in which the plague had broken out, maintained itself free from the “Great Mortality,” for a considerable time190; and examples of the preservation of individual families, by means of a strict separation, were certainly very frequent. That these orders must have caused universal affliction from their uncommon severity, as we know to have been especially the case in the city of Reggio, may be easily conceived; but Bernabo did not suffer himself to be deterred from his purpose by fear—on the contrary, when the plague returned in the year 1383, he forbad the admission of people from infected places into his territories, on pain of death191. We have now, it is true, no account how far he succeeded; yet it is to be supposed that he arrested the disease, for it had long lost the property of the Black Death, to spread abroad in the air the contagious matter which proceeded from the lungs, charged with putridity, and to taint the atmosphere of whole cities by the vast numbers of the sick. Now that it had resumed its milder form, so that it infected only by contact, it admitted being confined within individual dwellings, as easily as in modern times.

Bernabo’s example was imitated; nor was there any century more appropriate for recommending to governments strong regulations against the plague, than the 14th; for when it broke out in Italy, in the year 1399, and still demanded new victims, it was for the 16th time; without reckoning frequent visitations of measles and small-pox. In this same year, Viscount John, in milder terms than his predecessor, ordered that no stranger should be admitted from infected places, and that the city gates should be strictly guarded. Infected houses were to be ventilated for at least eight or ten days, and purified from noxious vapours by fires, and by fumigations with balsamic and aromatic substances. Straw, rags, and the like, were to be burned; and the bedsteads which had been used, set out for four days in the rain or the sunshine, so that, by means of the one or the other, the morbific vapour might be destroyed. No one was to venture to make use of clothes or beds out of infected dwellings, unless they had been previously washed and dried either at the fire or in the sun. People were, likewise, to avoid, as long as possible, occupying houses which had been frequented by plague-patients192.

We cannot precisely perceive in these an advance towards general regulations; and perhaps people were convinced of the insurmountable impediments which opposed the separation of open inland countries, where bodies of people connected together could not be brought, even by the most obdurate severity, to renounce the habit of a profitable intercourse.

Doubtless it is nature which has done the most to banish the Oriental plague from western Europe, where the increasing cultivation of the earth, and the advancing order in civilized society, have prevented it from remaining domesticated; which it most probably was in the more ancient times.

In the 15th century, during which it broke out seventeen times in different places in Europe193, it was of the more consequence to oppose a barrier to its entrance from Asia, Africa, and Greece (which had become Turkish); for it would have been difficult for it to maintain itself indigenously any longer. Among the southern commercial states, however, which were called on to make the greatest exertions to this end, it was principally Venice, formerly so severely attacked by the Black Plague, that put the necessary restraint upon the perilous profits of the merchant. Until towards the end of the 15th century, the very considerable intercourse with the East was free and unimpeded. Ships of commercial cities had often brought over the plague: nay, the former irruption of the “Great Mortality” itself had been occasioned by navigators. For, as in the latter end of Autumn, 1347, four ships full of plague-patients returned from the Levant to Genoa, the disease spread itself there with astonishing rapidity. On this account, in the following year, the Genoese forbad the entrance of suspected ships into their port. These sailed to Pisa and other cities on the coast, where already nature had made such mighty preparations for the reception of the Black Plague, and what we have already described took place in consequence194.

In the year 1485, when, among the cities of northern Italy, Milan especially felt the scourge of the plague, a special council of health, consisting of three nobles, was established at Venice, who probably tried every thing in their power to prevent the entrance of this disease, and gradually called into activity all those regulations which have served in later times as a pattern for the other southern states of Europe. Their endeavours were, however, not crowned with complete success; on which account their powers were increased, in the year 1504, by granting them the right of life and death over those who violated the regulations195. Bills of health were probably first introduced in the year 1527, during a fatal plague196 which visited Italy for five years (1525–30), and called forth redoubled caution.

The first lazarettos were established upon islands at some distance from the city, seemingly as early as the year 1485. Here all strangers coming from places where the existence of plague was suspected were detained. If it appeared in the city itself, the sick were despatched with their families to what was called the Old Lazaretto, were there furnished with provisions and medicines, and, when they were cured, were detained, together with all those who had had intercourse with them, still forty days longer in the New Lazaretto, situated on another island. All these regulations were every year improved, and their needful rigour was increased, so that from the year 1585 onwards, no appeal was allowed from the sentence of the Council of Health; and the other commercial nations gradually came to the support of the Venetians, by adopting corresponding regulations197. Bills of health, however, were not general until the year 1665198.

The appointment of a forty days’ detention, whence quarantines derive their name, was not dictated by caprice, but probably had a medical origin, which is derivable in part from the doctrine of critical days; for the fortieth day, according to the most ancient notions, has been always regarded as the last of ardent diseases, and the limit of separation between these and those which are chronic. It was the custom to subject lying-in women for forty days to a more exact superintendence. There was a good deal also said in medical works of forty day epochs in the formation of the fœtus, not to mention that the alchymists expected more durable revolutions in forty days, which period they called the philosophical month.

This period being generally held to prevail in natural processes, it appeared reasonable to assume, and legally to establish it, as that required for the development of latent principles of contagion, since public regulations cannot dispense with decisions of this kind, even though they should not be wholly justified by the nature of the case. Great stress has likewise been laid on theological and legal grounds, which were certainly of greater weight in the fifteenth century than in more modern times199.

On this matter, however, we cannot decide, since our only object here is to point out the origin of a political means of protection against a disease, which has been the greatest impediment to civilization within the memory of man; a means, that, like Jenner’s vaccine, after the small-pox had ravaged Europe for twelve hundred years, has diminished the check which mortality puts on the progress of civilization, and thus given to the life and manners of the nations of this part of the world a new direction, the result of which we cannot foretell.