The Ghost Map (2006)

I liked this book about the cholera outbreak in London during the summer of 1854. Johnson begins with a description of London and the scavengers who disposed of and recycled the waste of the city. Then he moves on to an account of the Broad Street outbreak along with details of how cholera attacks the body of the infected person.

The middle section of the book concerns the investigations that were carried on, especially those of Dr. John Snow and Rev. Henry Whitehead into the progress and possible causes of this particular cholera invasion. There is a great deal of discussion of the theories of the cause of disease, in particular the miasma theory that disease is caused by bad air and if air smelled bad then it was making one sick. Many of the recommended ways to treat diseases such as cholera involved making the air in the sickroom smell better. Hardly anyone believed in waterborne diseases. So, much of Snow's problem was how to show that cholera was waterborne.

The last section of the book shows how the eventual acceptance of Snow's theory led to cleaner water and better waste disposal in large cities in the industrialized nations. Then he discusses possible futures for today's cities that dwarf the cities of the mid-1800's. In some ways the discussion here may be even more important than the fascinating story of how cholera was tamed in Europe and North America along with other waterborne diseases.

Recommended.

Cholera originated in India. It is mentioned in Sanskrit texts circa 500 BC, and 2000+ years later it had not spread much beyond. By the late 1700s, it was affecting British soldiers in India. By the early 1800s, it had spread further into Asia, to Turkey and Persia and Japan and Russia, and to the US. In the 1830s, it hit England. Over the next two decades, outbreaks would flare and subside, leaving tens of thousands dead.

Cholera thrives when drinking water is contaminated by sewage, especially in a dense population with an unbroken cycle and readily accessible victims. The initial symptom is an ordinary upset stomach. The significant diagnostic symptom is the evacuation of water with small white particles, “rice-water stool”. Cholera is caused by the bacterium Vibrio cholerae. The small intestine has two cell types, which absorb and secrete water, maintaining a balance. Cholera covers the surface and injects a toxin disrupting the balance, so water is expelled with epithelial cells. The dehydration reduces blood flow, the heart pumps faster to compensate, blood vessels at the extremities constrict, gallbladder and spleen shut down, kidneys fail, waste accumulates. Until death is near, blood flow to the brain continues, so the victim is fully aware. The cure is simple: drink water to counteract the dehydration.

In the summer of 1854, when cholera terrified and devastated the neighborhood of Soho in London, eventually killing nearly 700 people, cause and cure were unknown. The predominant theory of disease was miasma, foul air, associated with poverty both by people who disdained the poor and by people who advocated on their behalf. This theory was accepted by the medical and political establishment, and by people who were otherwise reformers, such as Florence Nightingale and Edwin Chadwick, and there was certainly enough foul air in London to support it intuitively. The critical issue was of more precise correlation.

Until 1815, the London drainage system was intended for surface water, and putting sewage into it was illegal. Sewage, poured from buckets or flushed from water closets, instead went into cellar cesspools, which were emptied by the “night soil men”. Edwin Chadwick, head of General Board of Health in 1854, had pressed over decades for state engagement in the health of its citizens and investment in infrastructure, and championed the Nuisances Removal and Contagious Diseases Prevention Act of 1848, which required sewage to drain into a central system that emptied into the Thames. Meanwhile, a miscellany of pipes supplying water to wealthy homes had consolidated into ten major firms, each supplying water to private homes or public pumps in an area of the city, with intake pipes in the Thames. Parliament had ordered all intake pipes to be set above the tidewater mark by 1855, and some companies complied immediately, but others were holding out until the deadline. London infrastructure was on its way to improvement, but the previously clean Thames was in a state of worst case scenario for cholera. In 1849-1849, a cholera outbreak killed 15,000 people.

John Snow had become famous as the inventor of a device to control the dosage of ether, and was invited to administer chloroform to Queen Victoria when she gave birth in 1853. In the 1840s he set his mind to cholera, reading accounts of epidemics and details of deaths, and requesting information from water and sewer authorities. In an 1849 monograph, he argued that cholera was caused by an unknown agent ingested by drinking water contaminated with the waste of victims, not by miasma. Despite his reputation, this theory was received with skepticism. He did, however, persuade William Farr, city demographer and author of Weekly Returns of Births and Deaths, to track where victims got their water. His office, as it happened, was a five minute walk from Soho, so when cholera erupted in 1854, he was in a position to make door to door inquiries. Suspicion fell on the Broad Street pump. The local Board of Governors removed the handle, and the outbreak subsided.

Henry Whitehead was the assistant curate of St Luke’s Church in Soho. From his normal social rounds, and his calls to houses where people were dying, and he could see that cholera did not correlate with the cleanliness of the house. Giving a sermon after the cholera had subsided, he noticed a disproportionate number of poor elderly women in the pews who had been spared. He published a monograph on his observations and inquiries.

When the Board of Governors formed a committee to investigate the cholera outbreak, both Snow and Whitehead were invited to join. The significant contribution of John Snow was a map. To an existing map of cholera deaths and sewer lines, he added water pumps and a Voronoi diagram showing which houses were nearest which pump. The map made the connection clear; rather than a circular area of miasma, the shape was like an amoeba with deaths along streets leading to the Broad Street pump. The significant contribution of Henry Whitehead was the index case. Researching city records of deaths, he found reference to an unnamed baby who had died immediately before the cholera outbreak, in a house across the street from the Broad Street pump. He consulted the baby’s mother, who described soaking diapers and tossing the water into the cellar cesspool. Excavation revealed a decaying wall between the cellar and the pump.

In retrospect, the case was closed. In the real world, the miasma theory persisted until another cholera outbreak in the 1860s shifted opinion to the water theory. John Snow died in 1858. The cholera bacterium had been seen under a microscope by Filippo Pacini in 1854, but this was ignored until rediscovery by Robert Koch 30 years later, and general acceptance of the germ theory of disease.

This bare outline summarizes, but doesn’t do justice to, the engaging story telling that occupies most of the book. The conclusion is enthusiastic and perhaps longer than necessary praise of visualizing data in maps and local knowledge, and forms of communication at the intersection that get citizens involved in government action, which I skimmed because it overlaps with Steven Johnson’s later book Future Perfect.

(read 1 Feb 2013)

Riveting account of the Victorian cholera epidemic and the armchair science that helped unravel both the locus of the disease and the means of transmission. The last chapter, in which Johnson extrapolates some things about cities and epidemics, was especially fascinating and not a little alarming. Very well-written. Highly recommended. ( )

I miss the CD player in my car. I got through so many great non-fic reads driving to work. This one included. Its like mystery thriller. Find the source of the deadly disease before another epidemic breaks out. Great stuff. ( )

interesting, but rather thin on detail, mostly an opportunity for the author to digress on whatever he found interesting in his research and to editorialize on how modern urban life should be organized