Vol 61 No 2 2021
Page 2
Page 2
John Snow (1813-1858)
(Photo taken from Wikipedia
The causative organism of cholera was found in 1849 by the German microbiologist, Robert Koch (1843-1910) while he was investigating an outbreak of cholera in North Africa.
By Dr. Robin A. Cooke
The English physician John Snow (1813-1858) demonstrated that an epidemic of cholera in the Soho area of London in 1854 was caused by drinking water taken from the River Thames.
He began to make a map of where the people who died had lived.
500 of these lived within 250 yards of a public pump from which people obtained their water.
At that time people got their water from pumps attached to underground wells.
He concluded that the source of contamination must be from this pump in Broad St.
The employees of some commercial companies that had their factories close to the pump did not get cholera, but some other companies did have cholera deaths.
Snow found that those who did not get cholera had their own pumps.
Those that did get cholera, got their water from the pump.
After prolonged discussions with the local Board of Health, it reluctantly agreed to remove the handle from the pump ‘as a trial.’ As a result, the epidemic stopped almost immediately.
Snow still did not know how the water became contaminated in the first place.
The answer came through information obtained by a local minister of religion, Reverend Henry Whitehead.
One of his parishioners had a child who died from cholera acquired from another source.
On the day of the outbreak, she had washed his dirty napkin and dumped the water into a leaky cesspool just three feet from the Broad Street Pump.
John Snow plotted on this map the cases of cholera that were related to drinking water from the Broad St. pump. They were centered on Golden Square.
This technique for plotting cases of an epidemic became the model
for future generations of epidemiologists.
Golden Square in Soho, London on a beautiful sunny day.
A statue of King George 11 stands in the middle of the square.
A short walk of less than 100 metres leads to the John Snow pub and the site of the Broad St. pump.
The John Snow pub and the Broad St. pump. Black arrow points South to Golden Square. Red arrow points to the red brick curbing stone that marks the site of the pump.
A notice on the wall at the entrance to the John Snow pub.
Memorial plaque to John Snow on the wall
of the John Snow pub.
Left - red arrow – the red curbing stone. Right a village pump, similar to the Broad St. Pump, in the grounds of St. Paul’s Cathedral, London.
Acknowledgement: This account was abstracted from Wikipedia. Photographs taken by Dr. Robin A. Cooke.
John Snow had demonstrated that the way to stop the cholera epidemics was to take the sewage further down the Thames to be discharged into the North Sea.
No decision was taken to implement his recommendation.
However, the Government was forced to take action for
the following reasons:
In July and August 1858 there was a ‘heat wave’ in England.
There had been a rapid increase in the number of inhabitants
in London.
Flush toilets had been introduced.
All of this extra use of water resulted in the old sewers being flooded.
To add to the strain, the drought had resulted in a lowering of the level of the River.
This led to the openings of the discharge points of the sewers being exposed.
The smell of human waste and industrial effluent was all pervasive, and the press began to refer to it as ‘The Great Stink.’
It was so bad that Parliament was forced to pass laws to have the matter dealt with, and money was allocated to pay for this.
There was much wrangling, including from some administrators who still believed that the cholera was due to the Miasmas (bad smells) rather than some infectious agent carried in the water.
Finally, plans submitted by the Civil Engineer, Joseph Bazalgette (1819-1891) were accepted.
Joseph Bazalgette (1819-1891) A Memorial in the Victoria Embankment Gardens.
(Photo from Wikipedia)
He would build three main sewer pipes that would join up all the small sewers and drain by gravity further downstream.
They would take rain water as well as sewage.
Pumping stations would be built along the way to lift the lower level sewage into higher level pipes that would finally end in a big pumping station in the London Dockland.
This would then lift the effluent 36 feet (11 metres) into another sewerage pipe that ran 5 miles (8km) into a settling pond from which it was liberated on the high tide to take it into the North Sea.
In all there was:
1,100 miles (1,800 km) of small sewers and
82 miles (132km) of large pipes.
The three main pipes were accommodated by taking 52 acres from the River.
Retaining walls were built along the river side to protect the pipe from the water.
The pipe was laid and land fill was added to cover it.
Roadways or walkways were added on top.
The one on the South side was called the Albert Embankment (opened in 1896).
The city embankment was called the Victoria Embankment (opened in 1870).
The Northern Embankment was called the Chelsea Embankment (opened in 1874).
Bazalgette’s plan for the sewerage system of London
Black arrow – Chelsea Embankment
Red arrow – Victoria Embankment
Green arrow – Albert Embankment
Yellow arrow – Abbey Mills Pumping Station
(photo from Wikipedia)
The Abbey Mills Pumping Stations.
Original Romanesque style one left.
A new one right opened in 1997.
These Pumping Stations are on the site of
of the 2012 London Olympics July-Aug. 2012.
(Photograph taken by Dr. Robin A Cooke in
March 2012).
The concept designed by Bazalgette for dealing with the sewage from big cities has been copied throughout the world.
Epidemics of cholera still occur
The School of Tropical Medicine in Calcutta has a reference laboratory for tracking the organisms that cause epidemics in the region.
A lane that runs off The Strand down towards the Victoria Embankment. It covers one of the original effluent drains.
(Photograph taken by Dr. Robin A Cooke in 2015).
The Victoria Embankment viewed from Westminster Bridge.
(Photograph taken by Dr. Robin A Cooke on a bright sunny day in 2015)
Photograph taken by Dr. Robin A Cooke from the safety of a tourist bus in Calcutta in 1963. The monsoon had made the Hoogly River rise and flood the city. Human excreta was being dumped into the water.