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Destroying Angel: Benjamin Rush,

Yellow Fever and the Birth of Modern Medicine

by Bob Arnebeck

Rush traced the source of the epidmic of 1793 to rotting coffee on the Arch Street wharf

Chapter One  

Modern texts dispense with the etiology of the beginning of yellow fever's dozen years of terror with a few sentences. The great 1793 yellow fever epidemic in Philadelphia was caused when several thousand refugees came to the city fleeing the horrors of blacks killing whites on the island of Hispanola in the country we now call Haiti, then called Sainte Domingue. They brought with them an infectious disease, the yellow fever virus, and the Aedes aegypti mosquito which spread it. In three months upwards of 5,000 Philadelphians died of the disease.(1) How did Rush miss all the factors of the equation? Why didn't he blame the mosquitoes, why didn't he suspect a germ or virus, and what prevented him from deducing the source of the disease? And given all his mistaken notions, how was he able to identify the disease and correctly assess its epidemic potential after the city had experienced only a handful of cases, a feat that gave him status as a prophet?

In his happily titled book, The Conquest of Epidemic Disease, published in 1943, C.E.A. Winslow points out that "by 1700 there was available theoretical and observational evidence which should have made possible the formulation of our modern germ-theory of disease."(2) Another historian described the 18th century as "the age of insect study." Indeed medical doctors like Linnaeus, Fabricius, and John Hunter were leaders in the field.(3) Why did civilization have to wait until the late 19th century for Pasteur to prove the germ theory and Ross to show that the mosquito spread malaria?

Winslow suggests that the weight of theories, as old as Hippocrates, which blamed fevers on marsh miasmata and epidemics on occult qualities of the air, kept scientists from seeing the agency of fleas, lice and mosquitoes.(4) But the blame might just as easily be placed on observational science as ancient theory. Eighteenth century scientists were well aware that animals could spread disease. The bite of dog caused rabies and the bite of a snake could kill. They also knew how to spread disease themselves. Matter taken from the pustules of a smallpox victim was used to give the disease to others.

Because of the germ theory of disease, we appreciate how slight exposure to germs can still be fatal. However, the great medical advance of the 18th century, inoculation, seemed to prove that by decreasing exposure to contagious matter one lessened its affect. Inoculation was the art of giving a person a controllable case of smallpox to save him from a deadly case. At the beginning of the century the inoculated patient was prepared and protected by a regimen of purging. Then the Englishman Sutton showed that by minimizing the initial exposure to infectious matter, the severity of the resulting infection was lessened. Indeed Rush's first claim to fame in Philadelphia was his using the Suttonian method of inoculation, complete with the promise to patients that they would be saved from the rigors of the usual preparatory purges.(5) Thus insects seemed too small to spread lethal poison. They were beyond serious suspicion. Rush would illustrate the point to medical students by noting that the bite of the once feared tarantula had been proven to have "scarcely more effect than one of our mosquitoes."(6)

During the yellow fever epidemics those few who did blame insects were the exceptions that proved the rule. At the beginning of Philadelphia's 1802 epidemic, a correspondent to the Philadelphia Gazette who called himself Animalcule, a phrase used by the ancients to describe a fly and, after the advent of the microscope, to describe the organisms that instrument revealed, argued that the fever was caused by "minute insects depositing their eggs in the pores of the human body, and that the critical days were occasioned by the changes of the insect from the egg to the maggot, from the maggot to the torpid crisalis, and from thence to the fly, at which time it deserts the body leaving its shell, which must be thrown out by profuse perspiration or death will ensue."(7)

Here was a theory with possibilities to make medical history, except even Animalcule could not conceive of one insect's one bite causing the explosion of distressing symptoms that made yellow fever such a dread disease. The insects had to act en masse.

Rush never directly addressed Animalcule's theory, but indirectly he quite scientifically disposed of it. He noted the plethora of insects during epidemics, mosquitoes and others. However their abundance was caused by the deadly atmosphere, the same, of course, that humans were exposed to. So insects were a sign of pestilence, and no more.(8) Also diminishing the importance of insects was that they were so numerous they could not be readily measured. The rationalism of the Enlightenment placed great store in quantification.(9)

Thus though on the brink of discovering the germ theory of disease, scientists were thrown off the scent by the scientific advances of the 18th century. Germs and insects seemed immaterial as Lavoisier, Priestly and others showed that the gas all living things breathed could be measured and analyzed. Lavoisier thrust birds under water and into inverted glass jars, then manipulated the composition of the atmosphere they breathed rendering them lifeless in a matter of minutes.(10) What was a germ or a fly to a gasp of air, thousands of them a day. No one had shown that germs or insects could kill.

Lavoisier's experiment on human respiration; the drawing is by his wife

If the 18th century had followed-up the 17th century's use of the microscope as a tool of discovery by also making it a tool for measurement, the agency of germs in causing disease might have been discovered. However while we think of the microscope as the clinician's weapon to explode speculative medical theories with facts about pathology and physiology, that was not the case in the 17th and 18th centuries. Then the microscope was shunned by the advocates of clinical medicine. Thomas Sydenham, the English physician who won renown for bringing medicine back to the patients' bedside, included physicians prone to speculate on what microscopic germs might be doing as part of the tribe that wasted time in useless speculation. There was no need to wallow in "the abyss of cause." Even John Hunter, the father of morbid anatomy in England and a user of the microscope, down played its usefulness, especially in the study of blood.(11)

Of course, in medicine the crucial count is the number of sick people. Doctors who could not foresee bacteriology still could have appreciated epidemiology. Why didn't Rush deduce that a disease endemic in the tropics had to have been brought to Philadelphia by refugees from the tropics. With several thousand of them having just arrived, wasn't it obvious? As Winslow points out in his book, laymen had no trouble seeing that all epidemics were caused by the contagious spread of disease directly from person to person.(12) Doctors were not so sure, and, of course, doctors were right.

Plague, typhus, malaria, and yellow fever are not spread from person to person. Fleas, lice and mosquitoes must intervene. Here again, acute observation corrected common sense. But many doctors were prone to deny contagion all together. Sydenham, for example, thought smallpox was simply the result of a stage of development everyone went through, and that some managed badly.(13) Rush agreed that a bite from a rabid dog caused rabies, but he listed twenty other causes as well. Even syphilis was, medically speaking, not considered exclusively as a sexual disease. These doctors were wrong, but not necessarily because they were bad scientists. Not understanding the bacterial and viral causes of diseases they were overly observant. They smothered science with observation.(14)

The abyss these doctors wallowed in was an obsession with symptoms. Because modern physicians better understand physiology and pathology, they have a superior understanding of what symptoms mean. However modern physicians have used that knowledge to quickly get beyond, if not ignore symptoms. Tests not observation are key. The 18th century physician was fascinated with the most common symptom of disease, fever, that provides a kaleidoscope of observable variables. Fever was to the 18th century what cancer is to today. Fever is what people feared would cause their death; fever was the riddle that physicians sought to solve; fever was a mechanism regarded much as the pathogenic multiplication of the cancerous cell is today. If that were but understood, doctors could surely save suffering humanity.(22) When James Hutchinson left Philadelphia for medical training in Europe in the 1770s, he wrote back to a benefactor that he wanted "to expel the raging fever, to make diseases die."(23)

And this nice obsession with fever flourished before the fever thermometer.(24) Observation could not be resolved into a number. To observe a fever meant checking the pulse, tongue, skin color and moisture, body pains and mental acuity. As a minimum requirement to fulfill his obligation to his patient the doctor treating the first stages of any illness had to call on a patient at least twice a day.(25) All this to say that if the French refugees had come with the symptoms of yellow fever, it would not have escaped notice in 1793. So doctors saw no obvious connection between the nearly simultaneous arrival of yellow fever and the refugees, who, it should be noted, were not such objects of horror then as they often are today. These were middle and upper class whites and creoles with their well maintained slaves in tow. They were tinged with exoticism and grace that fascinated even the sober Quakers of the city.(15) Not surprisingly some of the French refugees were in ill health. The few carried off the ships who were mortally ill happened to be of noble blood, or soldiers with palpable wounds from fighting blacks in Cap Francois. Having fled in panic and not a few having been harassed by pirates and the Royal British Navy as they cruised north, many of the refugees were weak and thus susceptible to illness.(20) This did not escape the notice of Philadelphia's doctors. Rush blamed the French refugees for bringing an epidemic of summer influenza to the city.(21)

But that was not entirely their fault. These doctors thought there was a crucial third element involved in the spread of all fevers, the environment, and in those days, diseases with violent fevers like malaria which we now consider tropical were not confined to the tropics. They were endemic from Maine to Florida, from the Atlantic to the Mississippi, and terrifying epidemics could break out anywhere.(27) To blame some immigrants when those fevers broke out was to engage in witch hunts not science. What was required, as Hippocrates taught at the beginnings of organized medicine, was a heightened awareness of time, place and circumstance. The problem was compounded when people weakened by a long ocean voyage came to a place ill prepared to receive them. The port cities of America in the late colonial and Federal period were not quaint. Urban land speculation and its attendant evils of shoddy housing, over crowding and unconscionable profiteering thrived.(16) All American ports then were alive to the threat to public health that immigrants posed, but in most cases it was the immigrants who suffered as they failed to survive what was called "seasoning," that first year in the New World which after two hundred years of experience Europeans had come to realize could be very dangerous.(17)

For example an Englishman who had just arrived and an Irish woman who had landed in June 1793 both died at Dennie's North Water Street boarding house on August 4 and 6 respectively. Both were well attended thanks to the tax supported Overseers of the Poor and the privately supported Dispensary which assigned two young physicians, Philip Syng Physick and Isaac Cathrall, to treat the unfortunate emigrants. Physick thought the Englishman, a Mr. Moore, died so quickly that he might have been poisoned. Physick performed an autopsy, but found nothing suspicious.

Cathrall marvelled at the long morbid dance the fever put the Irish woman, Mrs. Parkinson, through: severe head and back pains, great thirst, offensive stools, much vomiting, delirium, red spots on face and breast, blindness, sore throat, hiccuping and death. She had languished a room away from the Englishman whose symptoms, coma and death in 24 hours, were completely different. Her family remained healthy. Malignant as the fever was, it evidently was not contagious, and so what passed was deemed business as usual on Philadelphia's Water Street, the storied landfall for most emigrants where not much account was taken of those who died before they moved beyond it.(18)

"Behind these wharfs, and parallel to the river, runs Water-Street. This is the first street which you usually enter after landing, and it does not serve to give a stranger a very favourable opinion either of the neatness or commodiousness of the public ways of Philadelphia. It is no more than thirty feet wide, and immediately behind the houses, which stand on the side farthest from the water, a high bank, supposed to be the old bank of the river, rises, which renders the air very confined. Added to this, such stenches at times prevail in it, owing in part to the quantity of filth and dirt that is suffered to remain on the pavement, and in part to what is deposited in waste houses, of which there are several in the street, that it is really dreadful to pass through it.... " Isaac Weld, Travels Through the States of North America...During the Years 1795, 1796 and 1797, pp.3-4.

In retrospect Rush thought that the first victim of yellow fever he saw was Dr. Hugh Hodge's child, a two year old girl suffering through her third summer.(28) The common killer of young children in the hot months was the bloody flux, dysentery. She did not have that, and when her fever did not resolve itself, as it often did in children, as the agony accompanying teething, Hodge sent for Rush. As the two emigrants, Moore and Parkinson, were dying a half block away, Rush looked at the little girl.

Rush knew the fright given parents when any child under 3 years old was sick. In Philadelphia one-fifth of newborns did not reach the age of two.(29) Rush and his wife Julia had lost four of their eleven children in infancy, and two still alive Ben and Julia were but 2 years and 9 months old respectively. Rush saw in an instant that he could do nothing for the Hodge child. The child was in God's hands. This resignation on Rush's part, though characteristic for the time, was memorable. Emboldened by the coming battle with yellow fever, Rush would seldom again leave a child to its fate.

The day after Rush saw Hodge's child, his old friend and sometimes publisher of his books and pamphlets, Thomas Bradford, sent word that his wife Polly was very sick. Almost 30 years ago she had been Rush's first love, the girl he had left behind when he went off to complete his medical studies at Edinburgh. (There the company of Jane, daughter of the Earl of Leven, a 16 year old who was beautiful, lively, and rich, made it easy for Rush, a social climber with considerable acumen, to forget Polly, the hatter's daughter.)(30) Rush found Polly with a bilious remittent fever exhibiting uncharacteristic inflammatory symptoms.

"Bilious" was a catchall phrase for some form of stomach distress thought to be caused by excess bile made evident by discolored stools or vomit. A remittent fever was one in which the pattern of sweats and chills diminished only to return the next day with equal or more force. This form of fever was more dangerous than intermittent fever which returned every second or third day. Usually in the heats of August, bilious remittent fevers prostrated a patient and rendered them peaked or sallow. Inflammatory symptoms, flushed face, rapid pulse, over excitability, were rare in August. Rush switched from mild herbal purges to a harsher chemical, calomel or mercurous chloride. And he had a bleeder take out 10 ounces of her blood, the common medical weapon against inflammation; Polly recovered.

The Hodge child in death and Polly in recovery shared one unsettling symptom. The child's corpse was yellow. Rush told Hodge that that was not uncommon in a fever with "symptoms of great malignity." Rush would soon note a yellowish tinge to Polly's skin. But beyond noting it, he thought little of it and saw no reason to think that she had anything more than the usual bilious fever. What began keeping him and his assistants busy was the outbreak of influenza.

In the second week of August he continued to have a few cases of malignant fever, that is to say any fever in which death seemed a too possible prognosis. The most distressing was that of the only son of the widow McNair. Before he died, blood gushed out of his nose. Rush blamed the violence of the disease on the "debility and fear" of the 19 year old.(31) In the following week Rush had more cases of influenza, scarlatina and dysentery, and thankfully no fevers as alarming as McNair's.

Then fever cases began to cluster. On August 18, Dr. Benjamin Say called Rush to consult on the case of a Water Street merchant. He found Peter Aston "sitting upon the side of his bed, perfectly sensible, but without pulse, with cold clammy hands, and his face of a yellowish color." He died a few hours later. Say was dumfounded because Aston had been strong enough to shave himself that morning. On Monday the 19th Hodge and Dr. John Foulke called Rush to Peter LeMaigre's boarding house on Water Street where Mrs. LeMaigre was "in the last stage of a highly bilious fever. She vomited constantly, and complained of a great heat and burning in her stomach."

As the three doctors left her room, Rush counted the "unusual number of bilious fevers" that had threatened, if not claimed, the lives of patients. Five of his had been seriously ill and McNair had died. Rush worried that "all was not right in our city." Hodge knew of four or five who had died "within sight of Mr. LeMaigre's door." One victim died 12 hours after getting sick. Dr. Foulke, who lived a few hundred feet away, called attention to a possible cause for the cluster of deaths. In late July water soaked coffee had been taken out of a ship and left to rot on a wharf. The stench had appalled the neighborhood.

In an effort to avoid the "abyss of cause," 18th century doctors favored simple explanations for a sickly environment. Rush's teacher at Edinburgh, Dr. William Cullen, argued that it was without doubt that fevers were caused by the miasmatic air from marshes acted upon by heat.(32) Rush had applied Cullen's lessons in his study of Philadelphia's break-bone [dengue] fever epidemic of 1780, published in 1789. Rush blamed the miasmata arising from the marshes south of the city. During its occupation of the city, the British army cut down all the trees that had purified the winds blowing up from the marshes.(33) (Actually dengue and yellow fever have similar etiologies. Both are viruses spread by the Aedes aegypti mosquito.) The effluvia arising from rotting vegetable matter like coffee beans was the same as that arising from a heated marsh save that it was more concentrated, more noxious, and hence liable to engender fevers that were more deadly and more contagious.

Rush had no trouble connecting all of his recent fever patients to the rotten coffee. He customarily quizzed his patients on where they had been as well as what they had been doing, eating, drinking or who they had seen. Hodge lived on Water Street. Polly Bradford had spent the afternoon with an acquaintance who lived near the rotting coffee. Although he had not seen a case of it in 31 years when he was apprenticed to Dr. John Redman, Rush told his colleagues that the city faced an epidemic of the "highly contagious, as well as mortal... bilious remitting yellow fever."

Rush's rapid recognition of the epidemic was a notable achievement. In 1791 an epidemic killed around 200 people in New York City. Not until two years later, after Rush recognized yellow fever in Philadelphia, would New York doctors realize that they too had had a yellow fever epidemic.(34) Rush had not seen a case of yellow fever in years, and epidemics, he thought, were becoming a thing of the past. In his medical school lectures he argued that as civilization advanced, diseases of the nervous system caused by luxury would predominate, and replace the types of fevers Sydenham had to deal with one hundred years before.(35)

However, in his lectures Rush did not ignore yellow fever, though his ideas were not well thought out. In discussing yellow fever he showed a well-informed inconsistency. He reported that the disease was endemic and not contagious in the West Indies, but that outside the islands, as was the case in Philadelphia in 1762, when it "spread like a plague, carrying off daily for some time, upwards of twenty persons," yellow fever was highly contagious. (This is an apt observation. In the West Indies most people were immune to the disease by prior exposure, and so the disease would not spread dramatically.)

To explain the inconsistency, Rush fell back on two ideas. First the conditions that would allow a tropical disease to come so far north, heat, humidity, & co., would debilitate people there to a far greater extent than such conditions would in the tropics where heat and humidity were common. So yellow fever would spread. Secondly it had long been accepted that the course of an epidemic was independent of its cause. Any epidemic disease took on a life of its own, flourishing in conditions which Hippocrates and Sydenham had called "an epidemic constitution."(36) The atmosphere became saturated with contagion, the nature of which was determined by the most powerful disease that developed epidemic potential. Thus the greater power of yellow fever, relative to the fevers common in Philadelphia, would allow it to predominate once it took hold. In the tropics other powerful malignant fevers were not uncommon, and so there it seldom reached epidemic potential.

It is easy to become impatient with such thinking. But given his era's myopia about insect transmission, Rush's way of looking at epidemics had a great advantage. It raised an alarm, promised no easy solutions and focused on early treatment. There was no need to round up recent arrivals from the tropics, because the danger was not so much sick people, as the very air attacking, with each breath, people weakened by the city's tropical summer weather. At the first sign of fever, diagnosis and treatment were easy because everyone was disposed to get the worst fever. Here was the right man at the right time in the right place with precisely the wrong ideas to be able, better than any contemporary, to assess and react to the situation correctly.

Go to Chapter Two

1. e.g. Michael Ruane, "Trial By Epidemic," Philadelphia Inquirer Magazine, Aug. 15, 1993, p 19.

2. Winslow, p 159.

3. Wolf, p 462; Hunter, p xiiff.

4. Winslow, p 161.

5. Hawke p 90; Garrison, p 405: Cronin pp 270-1.

6. Rush Lecture 1798 p 194, LC.

7. Phil. Gaz. Aug 4, 1802.  copy of the article

8. Rush, 1815, vol. 4, p 30.

9. Cohen, pp 81ff.

10. Holmes, pp 64ff.

11. Dewhurst, pp 63, 64, 92. Hunter, pp 40-42.

12. Winslow, p 182.

13. Dewhurst, p 34.

14. Rush 1815 vol 2, pp 193-4.

15. Cope, p 409. There arrived with these exiles from Hayti, some of the prettiest girls I ever beheld. They were very slightly tinged with African blood, their skins smooth, cheeks ruddy, eyes soft & sparkling, teeth without blemish & white as ivory, their countenances ever decked with smiles & good nature. Their hair was long & glossy black, their forms unexceptionally graceful, not inferior to the most elegant Grecian beauties & highly captivating.... They mixed not with the other islanders but were a class by themselves & seen mostly in clusters. By what means they lived was best known to themselves. The story went that some of them were rich & brought with them considerable sums of money. When affairs became more settled in their Island, they suddenly disappeared like splendid birds of passage & we saw them no more.

16. B. Smith p 163.

17. Duffy (2), p 218.

18. Currie, 1793, pp 15, 16, 29 & 30.

19. Fed. Gaz., Sept. 3, 1793.

20. Deveze (1), p 14; Deveze (2), p viii.

21. Rush 1815, vol. 3, p 40.

22. Rush's fascination with fevers will be made clear below; for a contemporaries obsession with them see Darwin's Zoonomia p 537ff. For a most influential 18th century book on fevers see Huxham's An Essay on Fevers.

23. Bell, p 103.

24. Rothstein, p 42.

25. Jardine's notes, pp 2-10.

26. John Morton, Jr., to John Morton Aug. 23, 1793, Haverford.

27. Currie 1792 pp 4ff (Even as Currie's correspondents tried to give optimistic assessments, the extent of endemic and epidemic fevers becomes apparent.)

28. Unless otherwise noted Rush's account of the early days of the epidemic come from Rush 1793 pp 8-15.

29. Currie 1792, p 112.

30. Hawke, p 61.

31. Rush Notebooks, Aug. 12, 1793.

32. Cullen, p 70.

33. Rush 1815, vol. 3, pp 231ff.

34. Addoms, p 8; Spector p 70.

35. Smith's notes.

36. Winslow, p 234.