The Ghost Map by Steven Johnson

The Ghost Map by Steven JohnsonThe Ghost Map by Steven Johnson is another book I found while reading the BBC History magazine. I read it was part about the history of the cholera outbreak in London, 1854. But it was also described as a detective story. We obviously have victims but where was the culprit coming from? What were the methods used to hunt it down and once located, how did they stop the spreading to other parts of the country?

The investigation would have its lasting effect on urban development, water distribution, sewer system installations, directing run-off waters and regulating the river Thames, and above all, educating people.

Yes, the cesspools and sewers smelled awfully that summer but did all these people die from what was in the air? Where factories to blame or, was it the deplorable hygiene of the poor and did that spread through the air? Sanitary and dietary conditions were not as we have them today. No refrigerator to keep food fresh, no purified indoor plumbing, and beer and alcohol were deemed safer than water. All these people living near each other produced more waste than the systems at that time could handle. Some collected waste in the basement, some in the yard, some had it shipped off.


In the summer of 1954, people started to feel sick. They had a mild stomach ache, started to throw up, got stomach cramps, and then got very thirsty. At the same time, they had watery diarrhea but unlike in cases of food poisoning it would not smell. It was almost without smell, very light in color, and if you watched closely you’d see small white particles. It is called rice-water stool and in 1854 it meant that death was imminent. Your pulse would be hard to find, your skin would turn blue and leathery, your cheeks would sink into their cavities, and your lips would turn blue until death took you away.


Cholera is a single cell bacteria. For this bacteria to be a threat to your health you need to ingest it. Physical contact with someone who has cholera does not affect you. It only will if the bacteria gets into your small intestine. There it reproduces fast and disturbs the cells that normally absorb water and distribute it across your body. If you are healthy, you distribute more water than you secrete. If you have cholera, you secrete so fast that you can lose up to 30% of your body weight in hours.

Cholera is not transmitted through the air so those who leaned towards the theory of miasma, that people literally got sick from bad smells, found out they were wrong. Those who thought you could catch it from the bodily functions of the poor, the contagionists, and who therefore didn’t care for them, were wrong too. Cholera is not something you inhale. You swallow it.

The Cure

There is a remarkable simple and very low-tech treatment for cholera and that is drinking water. Clean water and in copious amounts. Add some electrolytes to fortify the body and chances of survival are good. The clean water literally rinses the body of all bacteria and then it rehydrates itself with that clean water.


London had been hit with cholera before. But in the summer of 1854, people initially did not know what caused those deaths and later where the bacteria came from. This outbreak as discussed by Johnson, killed hundreds of people in an area from Broad Street (now called Broadwick Street) into the Soho district of the City of Westminster, London. The fact that the London sewer system had not yet reached Soho contributed to the massive outbreak. Not just people were without sewer system, business were too so slaughter houses, animal droppings on the streets, rotting fluids in cesspools, etc. clogged up the rudimentary Soho sewers. Many people collected waste in basements but ultimately those fluids seeped outside, puddled, overrun the area, and some eventually found its way to the Thames contaminating the water supply.

Baby Lewis

At 40 Broad Street, London, a baby died. We don’t know her name but she was born in March 1854. Her dad was a London police officer, Thomas Lewis, and mom’s name was Sarah. They had lost their first-born son when he was just 10 months old. The second child, Baby Lewis, would die August 28. In the early morning hours, she started to throw up and had a green, smelly stool. While waiting for the doctor to arrive, Sarah changed the diapers. She first soaked the soiled ones in a bucket with tepid water. Then later that morning, she tossed the water into the cesspool right in front of the house.

Medical Detectives

John Snow (March 15, 1813 – June 16, 1858) was an English physician and expert in the early adaptation of anaesthesia and medical hygiene. He is considered one of the fathers of modern epidemiology. The book describes how Snow first discovered that what made people so sick: cholera. Then the physician became a medical detective and used his great deductive skills and clear-headed analysis to solve the problem.

Henry Whitehead (September 22, 1825 – March 5, 1896) was a priest and the assistant curate of St Luke’s Church in Soho, London, during the 1854 cholera outbreak. He believed in the miasma theory until Snow’s theory that cholera came from water contaminated by human waste convinced him. He joined Snow in the investigations and indexed the outbreak in detail. Their joined work became the early version of epidemiology.


Johnson rightfully points out an element that cannot be stressed enough: never underestimate an amateur. Snow was a doctor not an expert in urban design or planning. Whitehead was a priest and not a doctor. Yet both men solved this case. The ultimate winner here is of course the value of interdisciplinary ideas and multidisciplinary thinking. And those ideas and thoughts can come from anyone!


We learn how Joseph Bazalgette engineered the system of underground sewer pipes that would carry both water and waste away from Central London. We read about further cholera outbreaks elsewhere in the world and how they were contained.

The book has extensive lists with notes, a bibliography, and an index. It allows the reader to dig further into details and explore other books, to study parts of the story, and to see where the author got all his information.

The book combines the history of cholera with urban planning and design, scientific thinking, and Victorian London. It doesn’t have the pace of a detective story and yet it is. It doesn’t read like a science textbook yet it informs and educate you. It is a brilliant mixture.

If you like history, medical sciences, finding culprits, and gathering the information needed to prove you are right, this is your book. Highly recommended reading!


My other book reviews are here.