John Snow

Hello, my name is John Snow. I was born in a town called York in England, on March 15th, 1813. Even when I was just a boy, I loved learning all about science and math. Numbers and experiments were like fun puzzles to me. I knew that when I grew up, I wanted to use my love of science to help people. I decided that the best way to do that was to become a doctor, so I could help people feel better when they were sick. I studied very hard because I wanted to be ready to care for anyone who needed my help.

When I grew up, I moved to the big, busy city of London to become a doctor. The city was full of people and new ideas. Back then, having an operation could be very painful. I wanted to find a way to make it easier for my patients. I discovered that I could use a special kind of sleepy air, called an anesthetic, to help people fall into a deep sleep so they wouldn't feel any pain during their operations. At first, some people were a little scared of this new idea. But in 1853, I was asked to help the famous Queen Victoria. After I helped her, many more people felt safe and trusted that this sleepy air was a good thing.

One year, in 1854, a very serious sickness called cholera spread through my neighborhood of Soho. It was a scary time, and many people were getting very sick. Most doctors and scientists at the time believed the sickness was spreading through bad air, which they called 'miasma'. But I had a different idea. I thought the sickness might be in the water people were drinking. To test my idea, I decided to become a disease detective. I got a big map of my neighborhood and started walking down every street. For every house where someone was sick with cholera, I put a little black dot on my map. When I was finished, I looked at all the dots. I saw that they were clustered together, all around one water pump on a street named Broad Street.

I took my map with all the dots on it to the city leaders. I showed them how almost everyone who was sick had been drinking water from the Broad Street pump. I told them, 'I believe the sickness is in the water from this pump. If we stop people from using it, I think the sickness will stop.' The leaders listened to me and agreed to try my idea. They went to the pump and removed its handle, so no one could get any more water from it. And just like that, it worked! Almost right away, people in Soho stopped getting sick. I had proved that the cholera was spreading through dirty water, not through the air. It was a wonderful discovery that would help save many lives.

My discovery helped cities all over the world understand how important it is to have clean, safe drinking water for everyone. Because of my work with the map and the pump, people learned how to stop the spread of sickness and keep their communities healthy. I lived to be 45 years old. Today, I am remembered for using science and maps to solve a deadly mystery and for helping start the field of public health, which is the important work of keeping everyone healthy and safe.