On Tuesday, September 5, 1854, the situation in Soho began to improve. People were dying, but others were recovering—and many of the people who were improving attributed their recovery to the fact that they’d been drinking lots of water from the Broad Street pump. Henry Whitehead believed that the cholera outbreak was almost over.
It took a long time before the medical community came to accept the waterborne theory of cholera, partly because there were many confounding factors—in particular, the fact that water could be a cure for cholera, as well as a cause.
Medical officers from the General Board of Health visited Soho to inspect the situation and scatter chloride and bleach on the streets. In the past five days, some five hundred residents of the neighborhood had died; however, the Board believed that it could reduce further disaster with chloride and bleach. Walking the streets that day was Sir Benjamin Hall, the new president of the Board.
The Board subscribed to existing medical theories of disease, and believed that it could ward off further death by eliminating bad smells—a timeless example of how people who desired to do good let misguided theory get in the way.
Benjamin Hall’s predecessor on the Board was a man named Edwin Chadwick. Chadwick had made a name for himself by conducting groundbreaking research into the London sewer system. He was a pioneer of the idea that the government should be engaged in protecting its citizens’ health and well-being, especially its poorest citizens. He was, for better or worse, an advocate of “big government” as people now understand it. However, Chadwick inadvertently caused the deaths of tens of thousands of cholera victims due to his lack of understanding of the germ theory of disease, and his irrational belief that disease was spread by bad smells.
Edwin Chadwick is a strikingly modern figure—he was a pioneer of the idea, now fairly uncontroversial, that the municipal government should play a significant role in helping its citizens survive. (At the time, there were many who advocated for various versions of Social Darwinism, the idea that the poor and the weak should be allowed to die in order to strengthen the gene pool). However, Chadwick also exemplifies the danger of enacting policy based on faulty theories, and the importance of basing policy on data and science, not just conjecture and conventional wisdom.
The problems that Chadwick wrestled with continue to challenge society in the 21st century: how can societies industrialize humanely?; how can government control the free market?, etc. But perhaps the most pressing question of Victorian society was a much more basic one: “What are we going to do with all of this shit?” London had a huge excrement problem—as Chadwick had shown in an influential 1842 study, human waste was piling up at an alarming rate, with no real plans for disposal. Some proposed using human waste as a form of fertilizer. Others suggested a system of sewers that could transport London’s excrement out to the countryside, where it could be put to use on farms. Some thinkers believed that human excrement could solve all problems of population growth—by feeding plants with human waste, society could grow without experiencing a crisis in resources.
It may seem unbelievable that one of the biggest, most intellectually sophisticated cities on the planet had no plan for dealing with its waste—but indeed, London in the 1840s had never had to deal with so many people living in such a small amount of space, and so there was no “master plan” for garbage disposal. Thinkers were intelligent enough to propose solutions to the problem, but until Chadwick, no government agency had the clout to enact any one of these proposals. The “shit crisis” pointed to a broader problem with urban planning itself—it wasn’t clear if it was possible, in the long run, for so many people to live together.
Edwin Chadwick launched a crusade on sanitation issues, resulting in the Public Health Act of 1848, which established the General Board of Health, with Chadwick leading it. Chadwick recognized that London needed new sewers. Under the current system, people discharged their waste into pipes, which flowed into the Thames River. At times, the sewers became so clogged that there would be an explosion of methane gas. However, Chadwick’s proposed solutions made the problem worse: the sewers were unclogged, but as a result, more sewage flowed into the Thames. As one Victorian said, “the Thames is now made a great cesspool instead of each person having one of his own.”
Chadwick thought that he was saving London from its own waste problem, but in fact, he created a much bigger problem when he dumped this waste into the Thames, where tens of thousands of people got their water every day. Because he lacked any understanding of the germ theory of disease, Chadwick was unable to execute policies that could genuinely help Londoners—only policies that appeared to do so.
Chadwick’s “innovations” in public health directly contributed to London’s cholera epidemics of the mid-19th century. It seemed never to have occurred to him that he was dirtying the water that millions of Londoners drank—he was so blinded by his theory of bad smells and miasmatic vapors that he couldn’t see the truth.
Theory blindness is an important theme of the book: Chadwick and other powerful establishment figures in London refused to see the facts, because they were so used to seeing things through the lens of their own ideas.
The miasmatic theory of disease remained powerful throughout the 19th century. In one edition of the Times, authors explored a series of theories about cholera, most of which were miasmatic—electric signals, “emanations from the earth,” etc. The theory that cholera was waterborne never came up. Even Florence Nightingale, the most beloved medical figure of the Victorian era, supported the idea that invalids’ “vapors” and “smells” must be kept as pure as possible. Many miasma theorists were arrogant about their views—they couldn’t tolerate the notion that they might be wrong. Yet none of them could explain the fact that scavengers and sewer workers spent all day inhaling horrible smells, and yet seemed no worse off than anybody else. Why was miasma theory so persuasive in England? Perhaps there is no single answer—many failures of imagination and analysis created the “perfect storm of error.”
The popularity of miasma theory in Victorian society contradicted some of the most basic requirements of good science, as articulated by scientific theorists such as Thomas Kuhn and Karl Popper. For example, Popper argued that good scientific theories should be falsifiable (i.e., other scientists should be able to test theories and prove them wrong). And yet, even after strong evidence contradicted the miasma theory, doctors continued to believe it, inventing elaborate rationalizations for their ideas. Perhaps, as Thomas Kuhn argued, miasma theory was a “paradigm”—an unverifiable underlying idea about a scientific phenomenon. In the end, it was arrogance, poor communication, and a general lack of common sense that led scientists to uphold their belief in miasma.
One partial explanation for the popularity of miasma theory was tradition. Since ancient times, doctors believed that bad smells caused illness. Miasma theory also worked well with religious tradition—for example, Henry Whitehead insisted that Earth’s atmosphere could, with the will of God, foster a plague. Another reason for the popularity of the miasma theory was instinct. Human beings’ sense of disgust has always led them to associate smell with illness—indeed, studies have shown that bad smells can inhibit the ability to think clearly, or do anything other than escape the smell. Smelling a rotting animal is disgusting, and it signals the presence of bacteria, but the smell itself won’t kill anyone. Thus Victorians mistook a sign of disease (the smell) for the disease’s cause—they mistook the smoke for the fire.
The idea of an intangible, almost atmospheric source for disease reflected many Christian theologians’ views on divinity. And although miasma theory was un-scientific in many ways, it was based on direct observation—people intuitively associate bad smells with sickness and disease, to the point where the two concepts can’t be easily separated. (Johnson’s discussion of “signs” in this section betrays some of his training as a semiotics major at Brown University.)
Another reason for the popularity of miasma theory is that smell is a stronger sense than sight. It only takes a few molecules for a human being to perceive the smell of decay—on the other hand, “eyes are useless at the scale of molecules.” People reacted negatively to the bad smells of 19th century London, but they had no way of seeing the hundreds of millions of cholera bacteria all around them. Furthermore, miasma theorists had lots of correlative evidence on their side: for example, the fact that many neighborhoods with high rates of cholera smelled disgusting. Furthermore, the miasma theory was a convenient way for Victorians to justify bigotry. Some doctors argued that bad smells had more of an effect on certain people than others, based on their internal “constitution.” Based on such arguments, others argued that the poor, or non-white races, were simply weaker. (However, there were also plenty of liberal thinkers, such as Nightingale and Dickens, who subscribed to miasma theory.)
Usually, one would hesitate to say that tradition or cultural values play a strong role in the development of science. But in fact, scientists are no more immune to cultural bias than anyone else. The popularity of miasma theory is a good example: scientists allowed their prejudices about certain patients to nudge their findings in the direction of conventional opinion. Put another way, scientists allowed their theories to reflect the common belief that the poor were weaker than the rich and thus, on some level, deserved to die of cholera. Bias, along with correlative evidence and a lot of other minor, vaguely defined factors pushed the medical community into accepting miasma theory long after it should have been proved wrong.
Miasma theory exemplifies the concept of “overdetermination”—in other words, an idea that persuades because of many small, compatible arguments, rather than any single, really convincing point. But in the end, the “miasma dam” burst, and scientists made progress toward solving the mystery of the cholera epidemic. In fact, the popularity of the miasma theory—and its persistent failure to better Londoners’ lives—made it easier for people like John Snow to see the theory’s weaknesses, so that miasma theory ultimately collapsed on itself.
John Snow spent Tuesday, September 5 walking through Soho, searching for cholera patterns. He visited the Registrar-General’s Office, where Farr worked, and spoke with Farr about the latest body counts for the neighborhood. Snow wondered if the Broad Street pump could be responsible for the cholera outbreak. He realized that he needed “footprints” to prove his point, not just “body counts.”
For the time being, Snow had no way of isolating the contagious agent in cholera; therefore, he tried a “macro approach”—analyzing hundreds of people’s behavior in the hopes of finding some overarching pattern.