Readers: Back in 2013, I did a multi-blog post on the 1854 cholera epidemic in London. Most of the reference material I used was based on Steven Johnson’s riveting book, The Ghost Map: The Story of London’s Most Terrifying Epidemic–and How It Changed Science, Cities, and the Modern World (see book cover below) What I want to discuss today are […]

Readers: This is something I have been meaning to post for a while. I think all of you Minard Map lovers, Data Visualization historians, KANTAR fans, and history buffs will find this really exciting. As many of you are aware, in 1869, retired French civil engineer Charles Joseph Minard documented and then summarized eyewitness accounts, […]

Donald Trump has become well-known for attacking people, news agencies, and even his own cabinet, using Twitter. AXIOS, a new media company, has visualized these attacks using a sankey diagram. Here is a blurb how AXIOS describe themselves. AXIOS is a new media company delivering vital, trustworthy news and analysis in the most efficient, illuminating […]

The Earliest Spot Map of All Dr. John Snow did not draw a map until December, 1854; the first spot map was produced in September of that year by Edmund Cooper, an engineer for the Metropolitan Commission of Sewers (see map below). Cooper’s investigation resulted from public complaints linking the sewers to the cholera outbreak. Rumors […]

Dr. John Snow is credited with taking bold action when he sensed that contaminated water from the public pump on Broad Street was the cause of deadly cholera during the 1854 outbreak in London. Here is what he wrote of his legendary action on September 7, 1854. [SOURCE] HANDLE OF THE BROAD STREET PUMP “I […]

Did the index (or first) case of the Broad Street Pump outbreak live at 40 Broad Street, close to the pump? Reverend Henry Whitehead thought so after a detailed investigation of cholera cases in 1854 following the outbreak. [SOURCE] The woman living at 40 Broad Street (Sarah Lewis, wife of police constable Thomas Lewis) lost […]

During the mid-1800s, there were two major theories on the cause of cholera being debated widely in medical circles throughout London. The organism that caused cholera, Vibrio cholerae, was not yet known and would not be until 1883, twenty-five years after the death of John Snow. In that year, Robert Koch, a German physician and bacteriologist, […]

John Snow (1813–1858) is revered as a founding father of two medical disciplines. Anesthesiologists remember him as the physician who first made anesthesia scientific by showing how the human body responded to different doses of anesthetic drugs, and how anesthesia affected the human physiology. In addition, Snow the practicing anesthetist is widely known for the […]

Description and Significance Vibrio cholerae is a “comma” shaped Gram-negative bacteria with a single, polar flagellum for movement. There are numerous strains of V. cholerae, some of which are pathogenic and some of which are not. [SOURCE] The bacteria infects the intestine and increases mucous production causing diarrhea and vomiting which result in extreme dehydration […]

The Broad Street Pump had a long reputation of being a reliable source of clean well water. It extended 25 feet below the surface of the street, passing the layers of accumulated rubbish and debris that artificially elevated most of London. It stretched through a bed of gravel all the way to Hyde Park, down […]