Lesson video

Hello, I'm Mr. Marchant and I'll be your history teacher for today's lesson.

I'm looking forward to guiding you for today's resources and helping you to achieve today's lesson objective.

Welcome to today's lesson, which is part of our Edexcel unit on Medicine in Britain and our AQA unit on health and the people.

By the end of today's lesson, you'll be able to evaluate the significance of John Snow's work for the fight against cholera in 19th century London.

There are three keywords which will help us navigate our way through today's lesson.

Those are epidemic, contaminated, and cesspit.

An epidemic is when a large number of people get the same disease over the same period of time.

We use the word contaminated for something that has become dirty or harmful to people's health.

And a cesspit is a large underground hole that is used for collecting human waste.

Today's lesson will be split into three parts and we'll begin by focusing on cholera epidemics.

In the 19th century, a new disease began to affect Britain, cholera.

Although cholera did not appear in Britain until 1831, it proved very deadly and killed more than 100,000 people before the century had ended.

Cholera is a disease caused by bacteria infections.

The bacteria which causes cholera can be spread through person to person contact.

Alternatively, the disease can be spread through water contaminated by the bodily fluids of people already infected with cholera.

Whilst cholera did not arrive in Britain until 1831, it proved very deadly very quickly.

Britain suffered from several cholera epidemics during the 19th century, and 50,000 people died during the 1848 to '49 epidemic alone.

In fact, some individual victims died in less than a day after becoming infected with cholera.

When cholera arrived in Britain, germ theory had not been developed and the role which microbes like bacteria can play in spreading disease was not understood.

Instead, the most common explanation given for cholera outbreaks was that it was spread by miasma, a belief that bad air can make people unwell.

This explanation meant their efforts to prevent the spread of miasma were often ineffective as they targeted the wrong things.

For instance, rather than ensuring water supplies were not contaminated, local authorities often emphasise the need to clean streets or burn barrels of tar in a mistaken effort to combat bad air instead.

So, let's make sure we have a secure understanding of everything we've just heard.

How many people died in Britain during the cholera epidemic of 1848 to 1849? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said the correct answer was 50,000.

50,000 people died in Britain during the cholera epidemic of 1848 to '49 alone.

Let's try another question.

What did people in 19th century Britain typically blame for cholera outbreaks? Was it contaminated water, divine punishment, or miasma? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said that the correct answer was C.

Miasma was typically blamed in the 19th century for outbreaks of cholera.

And this time we've got a statement on the screen which reads effective preventative action was taken to protect people from cholera epidemics.

But is that statement true or false? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said that that statement was false, but we need to be able to justify our response.

So why is it that the original statement was incorrect? Pause video here and press play when you're ready to check your answer.

Okay, well done to everybody who said cholera was wrongly blamed on miasma so common methods of prevention failed to protect people from the harmful bacteria which actually cause the disease.

And so that puts us in a good position to put all of our knowledge about cholera epidemics into practise.

I want you to answer the following question, why was cholera so deadly in 19th century Britain? You should include the following terms as part of your answer, epidemic, miasma, and water.

So pause the video here and press play when you're ready to reflect on your response.

Okay, well done for all of your effort on that task.

So I asked you why was cholera so deadly in 19th century Britain? And your answer may have included there were several deadly cholera epidemics in 19th century Britain, including one in 1848 to '49, which killed 50,000 people.

In large part, cholera proved so deadly because its actual cause was not properly understood.

Cholera infections are caused by a bacteria which can spread through person to person contact or through contaminated water.

However, most people in 19th century Britain blamed cholera on miasma.

This meant that many preventative actions were ineffective as they did not target the right cause.

For instance, local authorities often had barrels of tar burned to combat bad air, rather than ensuring water supplies were clean and uncontaminated.

So well done if your own response looked something like that model, which we've just seen, especially if you manage to include each of the three terms I asked you to.

And so now we're ready to move on to the second part of our lesson for today where we're going to consider the work of John Snow.

John Snow was a British doctor who lived and worked in London.

Snow's investigations into the spread of cholera during an epidemic in 1853 to '54 helped identify the role of contaminated water in spreading the disease.

John Snow was a popular and well-respected doctor who lived and worked in Soho, an area of London that was particularly badly affected by cholera epidemics.

Snow was already famous in the 19th century for his use of chloroform during surgical procedures.

Unlike most doctors at the time, however, Snow doubted that miasma was really responsible for cholera epidemics.

For one, Snow noted that cholera appeared to affect the guts of its victims, whereas if miasma was really responsible, it was the lungs that should have been affected.

During the cholera epidemic of 1853 to '54, Snow noticed that hundreds of people who lived on or close by to Broad Street, a road in Soho, died within 10 days of one another.

Snow decided to investigate the matter further.

He used a street map of Soho to record where deaths from cholera had occurred, recording these deaths as spots on his map.

Snow identified a clear pattern on his map.

The spots were most concentrated in the area closest to the water pump on Broad Street.

This pump was used by locals to get water from a well, which they could use for drinking, cooking, and washing.

Consequently, Snow theorised that the water obtained from the Broad Street pump must be responsible for spreading cholera.

As well as the evidence from his spot map, Snow conducted interviews with locals.

These revealed that almost all of the cholera victims in the area got their water from the Broad Street pump.

By contrast, workers in a local brewery who did not drink water from the pump had not been affected by cholera.

Based on all this evidence, Snow persuaded the local authorities to remove the handle from the Broad Street pump, meaning that it could not be used.

Subsequently, there were no more deaths from cholera around Broad Street as locals went to other pumps to get their water.

A later investigation of the well beneath the Broad Street pump went on to reveal that it was just one metre away from a cesspit which had a crack in its brick lining.

This meant that waste from the cesspit had contaminated the water in the well.

All of this allowed Snow to conclude correctly that cholera was not spread by miasma.

Instead, it was mostly spread as people came into contact with contaminated water.

So, let's make sure we have a secure understanding of everything we just heard.

We have a statement on the screen which reads, "John Snow aimed to prove that cholera was spread by miasma." Is that statement true or false? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said that that statement was false, but we need to be able to justify our response.

So why is it that that original statement was incorrect? Pause the video here and press play when you're ready to check your answer.

Okay, well done to everybody who said Snow doubted that cholera was spread by miasma as victims' lungs were unaffected by the disease.

And now I want you to study John Snow's spot map, which can be seen on the screen.

How does it suggest that water from the Broad Street pump spread cholera? Is it that all the spots are close to the pump? That the spots are most concentrated by the pump? Or that there are no spots by other pumps? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said the correct answer was B.

John Snow's spot map suggested that water from the Broad Street pump was spreading cholera because the spots he recorded where deaths from cholera were occurring were most concentrated by the pump.

And let's try another question.

Why did people using the Broad Street pump catch cholera? Is it that the water was contaminated by a nearby cesspit? That they were not using it to wash themselves properly? Or that the water pump was shared by too many people? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said the correct answer was A.

The Broad Street pump was leading to people catching cholera because its water was contaminated by a nearby cesspit, which was leaking.

So, we're now in a great position to put all of our knowledge about John Snow's work into practise.

Starting with the earliest, I want you to sort the events in the table into chronological order.

You should use the numbers one to six to indicate your answers where one represents the earliest event.

So, pause the video here and press play when you're ready to check your answers.

Okay, well done for all of your hard work on that task.

So I asked you to sort the events in the table into chronological order, and your answers should have been as follows.

The first event was that hundreds died in Soho, close to the Broad Street pump.

Secondly, John Snow used a spot map to record local deaths from cholera.

Thirdly, a handle was removed from the Broad Street pump then no new cholera deaths were recorded around Broad Street.

Following this, a leak from a cesspit on Broad Street was discovered.

And as the sixth and final event, you should have put that Snow concluded that contaminated water was spreading cholera.

So, really well done if you were able to order each of those events correctly.

And so now we're ready to move on to the third and final part of our lesson for today where we're going to think about the significance of John Snow's work.

John Snow's work accurately identified a link between water and the spread of cholera.

Unfortunately, Snow's findings did not receive the support from others which he had hoped for.

In 1855, John Snow presented his findings to the British Parliament.

Snow argued that the government needed to improve London sewage system to prevent future cholera epidemics.

However, these findings were largely ignored.

This was partly because politicians wanted to avoid the costs associated with Snow's recommendations.

Funding such a big project would require tax rises and politicians did not want to be blamed for this.

However, Snow's findings were also overlooked because there was a lack of scientific agreement to support his conclusions at the time.

While Snow received support from some of adopters, many scientists and officials continued to accept miasma as an explanation for disease, including those who work for Britain's General Board of Health.

On top of this, while Snow had demonstrated a link between contaminated water and the spread of cholera, he still couldn't prove what actually caused the disease.

It wasn't until the 1880s that cholera was proved to be caused by a bacteria.

The lack of this evidence in the 1850s made it easier for people to ignore Snow's arguments.

So, let's make sure we have a secure understanding of everything we've just heard.

I want you to identify two reasons why government officials did not immediately accept John Snow's ideas.

So the reasons you have to choose from are that many scientists and officials still believed in miasma.

That new research proved water had no role in spreading cholera.

That Snow's original research contained many mistakes.

Or that Snow's recommendations were expensive.

So which two of those reasons are correct? Pause the video here and press play when you're ready to see the right answers.

Okay, well done to everybody who said that the correct answers were A and D.

Many government officials did not immediately accept John Snow's ideas.

For one, because scientists and officials still believed in miasma.

And secondly, because Snow's recommendations to deal with cholera sounded expensive.

Significant government investment in London sewage systems did begin by the end of the 1850s.

Rather than John Snow's work, the specific trigger for this was the Great Stink in 1858, this was the name given to a period when the River Thames in London had become so polluted and contaminated with sewage that terrible smells covered the city.

The smells were so bad that meetings of parliament were disrupted and newspapers warned about the poisonous gases spreading from the river, raising concerns about miasma.

In August 1858, just months after John Snow had died, the government approved plans developed by Joseph Bazalgette to build a new sewage system in London.

Bazalgette's new system cost 3 million pounds, equivalent to roughly 1 billion pounds in today's money and took several years to build.

But once constructed, the system was able to remove 420 million gallons of sewage per day.

As a result of this improved sewage system, the problem of water contamination was mostly resolved in London.

And once Bazalgette's new sewers were fully constructed in 1875, the city suffered from no further cholera epidemics.

So, what prompted the construction of a new sewage system in London? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said the Great Stink in 1858 prompted the construction of a new sewage system in London.

And this time we have a statement on the screen which reads, "London suffered from many cholera epidemics until the end of the 19th century." But is that statement true or false? Pause the video here and press play when you're ready to see the right answer.

Okay, well done to everybody who said that that statement was false, but we need to be able to justify our response.

So why is it that that original statement was incorrect? Pause the video here and press play when you're ready to check your answer.

Okay, well done to everybody who said once London's new sewage system was completed in 1875, the city suffered from no further cholera epidemics.

So, we're now in a good position to put all of our knowledge about the significance of John Snow's work into practise.

Laura and Sofia disagree with one another.

Laura says that John Snow's work was key to ending cholera epidemics in London.

Whereas Sofia says that the ending of cholera epidemics in London had little to do with John Snow.

Whose view is more accurate, Laura's or Sofia's? Explain your answer in one paragraph.

So pause the video here and press play when you're ready to reflect on your response.

Okay, well done for all of your hard work on that task.

So I asked you, whose view is more accurate, Laura's or Sofia's? and your answer may have included Laura's view is more accurate than Sofia's.

John Snow was correct that contaminated water spreads cholera and his recommendations for parliament to fund a sewage system for London would've helped overcome this problem.

However, Snow's findings and recommendations were largely ignored.

Whilst Parliament did eventually approve and fund the construction of a new sewage system for, this was only after the Great Stink in 1858.

This was when terrible smells spread across London from the polluted Thames and raised fears about miasma.

It was this situation that prompted the government to take action, and it was only after this new sewage system was complete that London stopped suffering from cholera epidemics.

So well done with your own response looked something like that model we've just seen.

And so now we've reached the end of today's lesson, which puts us in a good position to summarise our learning about fighting cholera in London in the 19th century.

We've seen that thousands of people in London and across Britain died in cholera epidemics during the 19th century.

Based on his investigations around a broad street pump in Soho in 1853 to '54, John Snow correctly identified that contaminated water could spread cholera.

However, John Snow's findings were largely ignored by the government due to both the financial and scientific concerns of officials at the time.

And a new sewage system was not built in London until after the Great Stink of 1858.

This new sewage system did prevent future cholera epidemics.

So well done for all of your effort during today's lesson.

It's been a pleasure to help guide you for our resources today, and I look forward to seeing you again in the future as we continue to think about medicine in Britain and health and the people.