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“Moschetoes Were Uncommonly Numerous”

May 2024
9min read

Yellow fever killed 4,000 in Philadelphia in 1793, and puzzled doctors ignored the real clue to blame “miasmata” in the air.

Late in the evening of August 21, 1793, Dr. Benjamin Rush, Philadelphia’s most prominent physician, sat down “much fatigued” to write to his wife to inform her that a “malignant lever” had broken out on the city’s water front. The disease, which had carried off twelve persons, was “violent and of short duration.”

“It had,” he wrote, “in one case killed in twelve hours,” and in no case had it lasted more than four days. What he did not write was that he had become convinced that it was the dreaded yellow fever.

In the beginning of August Dr. Rush had been called to see the child of a colleague suffering from fever and jaundice. The child died. During the next two weeks Dr. Rush treated several other patients with similar symptoms, but not until August 19 did he suspect the true nature of the disease. Much distressed, he communicated his diagnosis to several colleagues and friends and shortly it became known throughout the city. He was disbelieved at first and even ridiculed by many, but the rapid spread and malignity of the disease soon left no doubt that it was indeed yellow fever.

Even is now moved swiftly. On August 22 the mayor of Philadelphia, Matthew Clarkson, officially notified the city commissioners of the outbreak of a contagious fever in the city and issued strict orders for the immediate removal and disposal of all filth from the streets.

On August 25 the College of Physicians held a special meeting to “confer upon the treatment of the existing malignant fever,” and recommendations for preventing its further progress were adopted.

On August 29 the governor of the state addressed the legislature on the situation in Philadelphia and reported on the measures taken in the emergency. He also ordered the mayor to enforce the recommendations of the College and to do everything “to prevent the extension of, and to destroy, the evil.”

Of all the infectious and contagious diseases, none of which was well understood at that time, yellow fever was one of the most deadly. Endemic at this period on the American mainland and the West Indies, it erupted from time to time without apparent rhyme or reason. During the last century there had been repeated major outbreaks in the Caribbean and on the mainland. In Philadelphia the last outbreak had been in 1762. It was the experience acquired as a young man during that epidemic that had let Dr. Rush recognize the prevailing fever for what it was and had Riled him with trepidation.

Why had the fever now recurred? Had it originated in the city? Had it been brought in? Civic pride was involved and men’s answers to these questions, regarded almost as a measure of their loyalty to the community, became the source of bitter discord.

Since all of the early cases had occurred in persons living near the water front, it was logical to search there for the source of the epidemic. Dr. Rush soon believed he had found it in the “putrid exhalations” from some damaged coffee which had been dumped on a wharf near Water Street and left to rot. The official investigations of Dr. Hutchinson, the inspector of sickly vessels, supported this view which, placing the origin of the fever squarely in the city, was very unpopular with the majority of the citizenry.

General acclaim, however, was accorded another theory which traced the epidemic to the French privateer San Culottes (twelve guns and 100 men), described as a Olthy and unbelievably overcrowded ship. This vessel had brought her prize, the Flora (out of Glasgow), into Philadelphia toward the end of July and had docked with her also near Water Street. Some “highly respected citizens and gentlemen” later attested that they had seen a dead body, sewed up in canvas, lying on board the Flora , and also said that corpses had been secretly landed at night from the two ships. All of which pointed clearly to a foreign origin of the epidemic.

The disease was soon city-wide. It was violent and resisted all treatment and the rumor began to spread that it was in reality the plague. Frequently it set in abruptly, with a shaking chill and high fever, but more often its onset was insidious. It “stole on” with headache, languor, and an upset stomach. Vomiting, stupor, and delirium followed. The hands and feet were cold, the pulse feeble and slow. The eyes, at first bloodshot, later became yellow. On the third or fourth day the entire skin was yellow.


Livid spots now appeared on the body and there was bleeding from the nose, the gums, and the bowels. A black vomit often heralded the impending end. Many died on the second or third day; few survived the fifth. “The common remedies for malignant fever have all failed,” wrote Dr. Rush. “Bark [quinine], wine, and blisters make no impression upon it.” Medical science was helpless.

The populace was panic-stricken. Whoever could do so left the city or made preparations to leave. All day long carts, wagons, and coaches rolled through the streets, taking whole families with their household goods into the country. Thousands upon thousands sought their salvation in flight from the doomed city.

The suddenness with which the fever had descended upon the city, the failure of the measures taken to prevent its propagation, the ineffectualness of medical treatment, all had an enervating effect upon those who remained. Nobody knew what to do or what not to do. In their fear and desperation people resorted to fantastic measures to stem the tide of the epidemic.

They burned fires in the streets (popularly regarded as an effective measure “to purify the air”) and when this was interdicted as being too hazardous they took to the no less perilous firing of guns — which also, needless to say, had to be forbidden. They observed the recommendations of the College of Physicians to an almost absurd degree and were constantly scouring and whitewashing their houses, which they hardly dared to leave. When they ventured into the streets they covered their noses and mouths with handkerchiefs or sponges soaked in vinegar or camphor, and they carried pieces of tar in their hands or pockets and often garlic in their shoes. They walked in the middle of the street in order to be as far away as possible from the houses which might harbor sick persons, and they assiduously avoided talking with anyone, even with close friends. If a hearse appeared in the distance, they turned and walked in another direction.

In their struggle for survival they became callous and heartless. Some parents abandoned their sick children, and persons complaining of a headache were often forced to leave the house and were thrown out into the streets. Not a few persons who were simply indisposed were forcibly committed to the yellow fever hospital where they contracted the disease. The sick, abandoned by relatives who were afraid of becoming infected, were left to die unattended, and the dead were hurried out of the house and buried before they were cold.

Already mortally afraid of contracting the fever, people became further disturbed when they saw that the doctors could not agree on how to treat it. In search of an effectual method of treatment, all the usual remedies having failed, Dr. Rush had taken recourse to purging with calomel, which in the past had been used with apparent success. With characteristic enthusiasm he felt that he had “at last arrested the fatality” of the epidemic, and he informed the College of Physicians that he had found a “cure” for the disease.

The majority of physicians disagreed, and their opposition to their eminent and sanguine colleague was further intensified by his subsequent, equally exuberant, advocacy of copious bleeding (he did not hesitate to bleed patients almost to the point of exhaustion). The controversy between Rush and his opponents was not only extremely acrimonious; it was, unfortunately, conducted publicly. Both factions repeatedly aired their views in the press, and thereby added greatly to the distress of the already sorely harassed laymen who did not know where to turn for medical help.

The death toll mounted unabated. Whole families were swept away. In the first three weeks of August, 1793, there were 160 burials in Philadelphia; from then to the middle of September almost 600; in the last two weeks of the month more than 1,000.

The exodus proceeded at an even more rapid pace; probably more than one-third of the 50,000 inhabitants fled the stricken city. Philadelphia, the most populous and prosperous metropolis in the United States, the capital of the young American republic, took on the aspect of a ghost town. Many houses and shops were deserted and boarded up. Traffic was almost nonexistent, and in the empty streets “the hearse alone kept up the remembrance of the noise of carriages or carts. … ”

All the city magistrates, with the exception of the mayor, deserted their posts: the governor had retired to the country because of illness; nearly all the state officers had gone; most, if not all, of the officers of the federal government were absent, and the President of the United States, “according to his annual custom, had removed to Mount Vernon.” Government was virtually at a standstill.

In the middle of September the mayor called a meeting to discuss measures for the care of the city’s indigent, whose situation was especially precarious. The meeting, to which the public at large had been invited, was poorly attended. But out of its deliberations there emerged a committee which gradually extended the scope of its activities to such an extent that it became the de facto city government.

The great burden was carried by the eighteen persons on this committee, who placed themselves entirely in the service of their fellow citizens. Their efforts were supported by the majority of the physicians, by many of the clergy, and by the elders of the African church, who marshalled the forces of their congregation, many of whose members rendered selfless service as nurses and gravediggers.

The situation continued to deteriorate. There was no letup in the spread of the fever and the death rate rose ever faster. Two thousand persons perished in October. Business and commerce lagged, prices rose as provisions became scarce; the city was faced with the specter of famine. A spirit of utter despondency and fatalism took possession of even the staunchest. No ray of hope was anywhere discernible. How was it all going to end?

Was Philadelphia, in the eyes of the Reverend Heinrich Helmulh “by far the most luxurious and dissipated of North American cities,” not indeed experiencing a divine visitation? Were not its citizens receiving deserved punishment for their drunkenness and lewdness, their pride, avarice and uncharitableness, their fraudulence and their quarrelsomeness? Had they not, in their sinfulness and frivolity, even legalized theatrical performances and imported from “luxurious” Europe no less than seventy to eighty actors and actresses and other stage people?

Thus reasoned the fiery minister of the Lutheran congregation who, it should be pointed out, did not limit himself to castigating his city. Unflinchingly he stood by it in this time of distress, nursing its sick and burying its dead.

The air of mystery which surrounded the epidemic added greatly to the general sense of frustration. The physicians, who at this period knew nothing of germs and viruses, groped in the dark. They did not know how the fever spread from person to person, nor could they fathom its material basis. True, they spoke of “miasmata,” theoretical poisonous particles supposedly floating in the air, as the cause of the fever, all the while well aware that they were treading on very infirm ground. They had no dear concept of the nature of these miasmata — whose very existence was, in fact, open to doubt.

In their uncertainty the doctors regarded many things as being connected with the fever. “Moschetoes (the usual attendants of a sickly autumn) were uncommonly numerous,” commented Dr. Rush. His observation was pregnant with future promise to which he, however, obviously attached no greater significance than to the irrelevant fact, recorded in the very next sentence, that an occasional dead cat had added to the “impurity of the streets.”

Since no one then really knew anything about the nature of yellow fever it is not astonishing that all attempts to halt the epidemic failed. Apparently the disease would have to run its course, uninfluenced by human measures, until terminated by the onset of rain and cold. All hope was placed on this contingency. But the weather continued to be fine and “the light of the morning mocked the hopes that were raised by a cloudy sky in the evening. The sun ceased to be viewed with pleasure.”

Then, suddenly, towards the end of October, the epidemic broke. The death rate dropped precipitously. There had been hardly any rain and the weather had been as warm as during the most fatal period. Again the unexpected had happened. Once more the disease had taken an inexplicable turn. Its end had come as mysteriously as had its onset and both were as little comprehensible as was the course it had taken. “Human wisdom and calculation,” wrote Mathew Carey, the most important lay chronicler of the epidemic, had been “set … at defiance.”

People began coming back to Philadelphia. Houses and stores were reopened. Vehicles again appeared on the streets; pedestrians once more went about their business. December 12 was designated as a day of thanksgiving. The city took on its normal appearance.

The ravages had been dreadful. More than 4,000 persons had succumbed in a period of three months. Few persons were spared the loss of dear ones. Many children had become orphans; many parents childless. The epidemic was long remembered.

But it was not to be the last great outbreak of yellow fever in the United States. Two years later there was a serious epidemic in New York; five years later Philadelphia was once again in its grip. In the following century the same pattern prevailed. Smaller and greater outbreaks followed one another in rapid succession. Especially the South was hard hit, but seaport towns as far north as Boston and Halifax were not spared. New Orleans, Savannah, Charleston, and Baltimore bore the brunt. Nearly 8,000 persons perished in New Orleans in 1853; 13,000 died from yellow fever in the Mississippi Valley in 1878.

In the second half of the Nineteenth Century, with the researches of Pasteur and Koch, great advances were made in the recognition of infectious diseases. Yellow fever remained an enigma. At last, in 1900, more than 100 years after the great Philadelphia epidemic, Major Walter Reed of the U.S. Army Medical Corps, following a lead of the Cuban physician, Dr. Carlos Finlay, demonstrated that yellow fever is transmitted from man to man by the bite of the mosquito known as Aëdes aegypti. The way to the conquest of this terrible scourge had been opened. An extensive program of mosquito extermination brought the disease under control. And with the isolation of the virus causing yellow fever, three decades later, it became possible to produce an effective anti-yellow-fever vaccine.

No one remembered that on August 29, 1793, there had appeared an anonymous letter in the Philadelphia American Daily Advertiser, describing a simple and cheap method of destroying mosquitoes, “those poisonous insects … so distressing to the sick, and troublesome to those who are well.” A little oil poured into cisterns and rain-water casks, the breeding places of mosquitoes, would kill the “whole brood.”

In the excitement of those dreadful days the letter went unnoticed. Philadelphians had more important things to do than rid themselves of a nuisance. How different might the fate of their city have been had they paid more attention to ”… the usual attendants of a sickly autumn.”

Dr. Laurence Farmer is a physician with special interest in the history of medicine. His recent book, Doctors’ Legacy (Harper), is a collection of physicians’ letters during the last two and a half centuries.


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