The Ghost Map: Chapter 5 Summary & Analysis

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.

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.

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.

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.

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’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.

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.”

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.

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.)

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.”