If Snow and Whitehead's Broad Street investigation showed that urban intelligence could come to understand a massive health crisis, Bazalgette's sewers proved that you could actually do something about it.

[...]

The great killer of the nineteenth-century metropolis had been tamed by a combination of science, medicine, and engineering.

The ghost map [207,215/299]

(Steven Johnson, 2006, Penguin Books)

It marks a turning point in the battle between urban man and Vibrio cholerae, because for the first time a public institution had made an informed intervention into a cholera outbreak based on a scientifically sound theory of the disease. The decision to remove the handle was not based on meteorological charts or social prejudice or watered-down medieval humorology; it was based on a methodological survey of the actual social patterns of the epidemic, confirming predictions put forward by an underlying theory of the disease's effect on the human body. It was based on information that the city's own organization had made visible. For the first time, the V. cholerae's growing dominion over the city would be challenged by reason, not superstition.

The ghost map [162-163/299]

(Steven Johnson, 2006, Penguin Books)

[...] methane and putrescine and cadaverine are the smoke. Microbes are the fire.

[...] They mistook the smoke for the fire.

The ghost map [130-131/299]

(Steven Johnson, 2006, Penguin Books)

Dying of dehydration is, in a sense, an abomination against the very origins of life on earth.

The ghost map [38/299]

(Steven Johnson, 2006, Penguin Books)

[...] it's been one long Age of Bacteria on this planet since the days of the primordial soup. The rest of us are mere afterthoughts.

The ghost map [36/299]

(Steven Johnson, 2006, Penguin Books)

Once you began emitting rice-water stools, odds were you'd be dead in a matter of hours.

The ghost map [34/299]

(Steven Johnson, 2006, Penguin Books)

Imagine if every time you experienced a slight upset stomach you knew that there was an entirely reasonable chance you'd be dead in forty-eigh hours.

The ghost map [32-33/299]

(Steven Johnson, 2006, Penguin Books)