Evidence!: How Dr. John Snow Solved the Mystery of Cholera

by Deborah Hopkinson, Nik Henderson (illustrator)

The incredible true story of the doctor who traced London's cholera outbreak to a single water pump, and went on to save countless lives through his groundbreaking research!Dr. John Snow is one of the most influential doctors and researchers in Western medicine, but before he rose to fame, he was just a simple community doctor who wanted to solve a mystery.In 19th century London, the spread of cholera was as unstoppable as it was deadly. Dr. Snow was determined to stop it, but he had a His best theory of how the disease was spread flew in the face of popular opinion. He needed evidence, and he needed to find it fast, before more lives were lost.Taking on the role of detective as well as doctor, Dr. Snow knocked on doors, asked questions and mapped out the data he'd collected. What he discovered would come to define the way we think about public health to this day.This compelling nonfiction picture book is a timely reminder of the power of science to save lives.

Genres: Picture Books, Nonfiction, Science, History, Biography, Death, Stem

40 pages, Hardcover

Published August 13, 2024

About the author

I write nonfiction and historical fiction, picture books, and Golden Books. I speak at school, libraries, and conferences. I also love to garden and offer manuscript critiques. (Deborahhopkinson@yahoo.com)

NEW books in 2024 include DETERMINED DREAMER: THE STORY OF MARIE CURIE, illus by Jen Hill, ON A SUMMER NIGHT, illus by Kenard Pak, TRIM HELPS OUT and TRIM SAILS the STORM, illus by Kristy Caldwell, EVIDENCE! illustrated by Nik Henderson, and a nonfiction work called THEY SAVED THE STALLIONS. I'm delighted to say that Trim Helps Out, Trim Sails the Storm, On a Summer Night and Evidence! are all Junior Library Guild selections.

I live and work in Oregon and travel all over to speak to young readers and writers.

Reviews

[Brooke - TheBrookeList · Rating 5 out of 5]

Nonfiction for kids reads well when it read like fiction. This is a story that reads like a story. Dr. John Snow working on Broad Street to find evidence for his theories on how cholera spreads. Can he get enough evidence in time to save lives, and stop the spread of the disease? It's a look back into history that brings excitement and wonder to solving a mystery. Well-written and an easy read, kids will be thinking about mysteries they could solve and how they could save the world themselves someday. The dark style has a Neil Gaimen feel and the artwork is just right.

Read as a nomination in the nonfiction book award category as a panelist for Children's and Young Adult Bloggers' Literary Awards (Cybils Awards).

[Bonnie Grover · Rating 5 out of 5]

The true story of the doctor who traced London's cholera outbreak to a single water pump and went on to save countless lives. This book is a great reminder of the power of science to save lives.

[emyrose8 · Rating 5 out of 5]

4.5- A picture book about a doctor who began the science of epidemiology. Bio/photo of Dr. Snow in the back plus a list of infectious diseases and their causes.

[Steph · Rating 5 out of 5]

Beautifully and hauntingly illustrated, not only is this a fascinating of the cholera outbreak and Dr. John Snow’s brilliance to stop it in its tracks - but it’s bound to bring up solid discussion on the importance of gathering evidence to build a case. Awesome informational picture book!

[Wren · Rating 5 out of 5]

About a decade ago, I read Ghost Map, which is an account of John Snow's investigations that lead to the removal of the handle of the Broad Street pump. It's great to see this story about epidemiology or medical detection told for younger readers.

Illustrator Nik Henderson helps author Deborah Hopkinson tell the story. Henderson draws London in it's industrial, foggy, smoggy, glory with a big dose of sepia to mimic the early daguerreotype and tin type photos of the mid 19th Century. (The story stats in 1854.)

People in London were getting ill from cholera, and the prevailing medical model of the type was that vapors caused illness. By mapping the households affected by cholera, he had an hypothesis that it was the water. But he did not have access to a microscope that would reveal the culprit.

"John sees nothing unusual under his microscope. The tools in his lab aren't powerful enough to reveal the tiny organisms we now know were there (vibrio cholera). Even though he can't see any evidence, John won't give up. He'll need another way to show the people who got sick drank water from the [Broad Street] pump."


Snow knocked on doors and interviewed people to ask if anyone in the house drank from the Broad Street pump and if they got ill. There was a high correlations. But the vapor theory could still persist because people were close enough to breath air from the same sewers and rotting food. It wasn't until he heard of a case from miles away where he learned a woman was receiving water from the Broad Street pump from relatives delivering it to her. That was a strong piece of evidence.

That was enough to justify removing the handle from the pump so that others would not drink the cholera infected waters (where infected people's vomit and human waste had been dumped), and it slowed then and stopped the outbreak.

The backmatter contains a little more about the Broad Street pump, snow, and then lists other diseases whose causes were discovered.

[Barbara · Rating 3 out of 5]

This medical mystery [3.5] is so carefully described that it will keep many youngsters enthralled and trying to guess what has caused all those folks to get sick and die. London in 1854 isn't a place that is particularly fresh-smelling or safe for its residents. When the city's citizen sickens, experts blame it on garbage that is rotting and bad air. But Dr. John Snow is convinced that they are wrong, and that the origins of cholera can be traced to water. He maps the clusters of recent cases, and looks for what they might have in common, finally surmising that it could possible that they all drank the same water. Although he collects water from a pump that he suspects has unsafe water, his microscope shows nothing he can use to prove his suspicions are right. Desperate to prevent further deaths, Snow interviews the families of victims, eventually locating a woman who did not live in the area where the suspicious water originated but whose sons had sent her a weekly container of the water. Readers will be on the edge of their seats as they follow Snow on his investigation, and then when they read the back matter explaining how the water became contaminated, they'll be even more intrigued and disgusted at some of the practices of that time. To add to this picture book's timeliness, there is a list of other infectious diseases and their causes in the back matter. Moody illustrations, created with graphite, charcoal, and digital coloring, evoke the time and place when Snow's investigation took place while the text is filled with tension and foreboding as readers realize that many more lives will be lost if Snow can't solve the problem of cholera. This picture book is a good choice for a science classroom library since it has many elements that evoke curiosity.

[Heather · Rating 4 out of 5]

When cholera breaks out on Broad Street, everyone is convinced it is because of the bad air. After all, London in 1854 was incredibly stinky, with factories spewing yellow smoke, streets lined with horse poop, and cesspools polluted with sewage and human waste. But one doctor, John Snow, thinks something else is the source. He believes that the intestinal issues caused by cholera suggest the disease is caused by something people eat or drink. With patience, he searches for clues and evidence, like a medical Sherlock Holmes. Studying maps of the outbreaks, he narrows in on the Broad Street water pump. But he needs evidence to convince the local neighborhood board to take action that will stop the outbreak. Hopkinson’s narration of this historic medical milestone feels as suspenseful as any murder mystery. Snow’s persistent tracking of the disease through maps and thorough questioning continues to inspire scientists today, according to Hopkinson’s note in the back matter. Henderson’s detailed, soft charcoal and graphite illustrations use muted colors to give the feel of the dirty nineteenth century London described in the book, and also add to the suspenseful tone. In addition to the author’s note on the Broad Street pump cholera outbreak, the back matter includes a short biographical sketch of Dr. Snow, a list of some of the major infectious diseases and their causes, and a bibliography of online and print resources about Dr. Snow and epidemics. This inspiring book about determination and persistence would be a perfect introduction to a unit on infectious diseases or the scientific method. Give this to readers who enjoy biographies of scientists who challenge popular wisdom or accepted beliefs.

[Read Ribbet · Rating 5 out of 5]

Deborah Hopkinson has written other favorite nonfiction picture books: Sweet Clara and the Freedom Quilt, Sky Boys, and Abe Lincoln Crosses the Creek. In Evidence, she returns toa topic that she wrote about in a young adult book -- Dr. John Snow's search for the cause of Cholera. Beautifully illustrated by Nik Henderson, Hopkinson shows the power of inquiry and the search for evidence. We see London in the 1800's and the horrible conditions under which people lived especially as it related to hygiene and sanitation. Then we see Dr. Snow use evidence to track down the source of a Cholera outbreak trying to challenge current theories about the spread of the illness. It's a great book to show the importance of science, evidence and evidence-based solutions. The book has some additional information in the end notes. There is a list of other major illness and their causes. The book ends with a list of resources for further exploration of this subject and topic.

[Kristen · Rating 4 out of 5]

A really accessible nonfiction picture book about how Dr. John Snow figured out what caused cholera. This reminded me of how much I was fascinated by The Ghost Map: The Story of London's Most Terrifying Epidemic—and How It Changed Science, Cities, and the Modern World, and I think this is a great entry point for kids who are interested in the history of disease or are curious about past epidemics to learn more. A well done, succinct picture book on a really interesting part of history that might feel all the more relevant to kids who have seen a pandemic up close.

[Zan Porter · Rating 4 out of 5]

The incredible true story of the doctor who traced London's cholera outbreak to a single water pump, and went on to save countless lives through his groundbreaking research! Dr. John Snow is one of the most influential doctors and researchers in Western medicine, but before he rose to fame, he was just a simple community doctor who wanted to solve a mystery. In 19th century London, the spread of cholera was as unstoppable as it was deadly. Dr. Snow was determined to stop it. His best theory of how the disease was spread flew in the face of popular opinion. He needed evidence, and he needed to find it fast, before more lives were lost. Taking on the role of detective as well as doctor, Dr. Snow knocked on doors, asked questions and mapped out the data he'd collected. What he discovered would come to define the way we think about public health to this day."-

[Katie Hutchison Irion · Rating 4 out of 5]

Evidence! How Dr. John Snow Solved the Mystery of Cholera by Deborah Hopkinson and Nik Henderson is a terrific nonfiction book that is accessible, interesting, and engaging. In August of 1854, cholera exploded in London. The disease was taking over London and everyone was trying to figure out how and why it was spreading. John Snow started taking notes, observing, amassing evidence in order to find the origin of the disease. Through his diligence and devotion to scientific methods, he is able to find out that the outbreak started from the Broad Street pump! His discovery and strong evidence lead the people to dismantle the Broad Street pump, helping hundreds stay healthy. Today, if you go to Broad Street in London, you will find a plaque dedicated to John Snow and his commitment to evidence! We really enjoyed this book.

[Sandy Brehl · Rating 5 out of 5]

This account of doctor/scientist John Snow and his quest to prove the source of cholera outbreaks in 19th century London is told very effectively and demonstrates examples of investigative medicine.
The author uses a very effective narrative device to insert potentially/imagined commentary by Dr. Snow along the way, introducing short, italicized dialogue with the phrase, "it's easy to imagine he might ask..." or "we can imagine he said..."
This allows readers to distinguish quite clearly the information drawn directly from sources and the lines that are NOT attributed but advance the narrative. That, along with expansive back matter about Dr. Snow and the events of the time include references and bibliography.

[Jessica Harrison · Rating 5 out of 5]

Deborah Hopkinson is an expert storyteller. Through her deft hands, Evidence! plays out like a great mystery, the likes of which only great detectives can solve. Her text is engaging and clear enough that young children won’t need a lot of explanation to understand.

Illustrator Nik Henderson uses graphite, charcoal and digital coloring techniques to masterfully set the tone. This is the type of book readers young and old will be drawn to. There are numerous classroom applications as well as just being fun to read.

Compelling backmatter provides more information about the Broad Street Pump, Dr. John Snow and a list of major infectious diseases and their causes.

[AllyP Reads Books · Rating 3 out of 5]

3.5 stars.

Good book that will give kids insight into how doctors and scientists can trace origins and causes of infectious diseases, not just cholera. It does leave some questions unanswered, like why didn't everyone get sick. Also, once they removed the pump handle, where did people get their water? It seemed if people had to line up to use the pump, water was already hard to come by, and then their source was completely eliminated with no other option. Plus, figuring out cholera was transmitted through the water doesn't really help unless you figure out how to keep poop out of the water and develop more sanitary conditions, which was not addressed in this book.

[Ms. Yingling · Rating 4 out of 5]

School library copy

I really enjoyed Hopkinson's 2013 THE GREAT TROUBLE. https://msyinglingreads.blogspot.com/...

One of our science teachers who also has a Medical Detectives class was talking to me about possible picture books to read to her class, and this was the automatic choice. It's a good overview of the mystery and walks readers through Dr. Snow's scientific process.

My only complaint is that the print is very small for a picture book, and on almost every page, there was plenty of room to make the print much bigger. End notes are helpful.

[Erin · Rating 4 out of 5]

A look at how one man pushed popular opinion a little closer to reality. While most people assumed that cholera came from breathing the bad, stinking air that the disease left all around, he did not see that connection. Instead he sought out a different one: the drinking water.

This is a simple look at how Dr. John Snow figured out what was causing this outbreak of cholera, and how he convinced his community to do something about it.

Demonstrates the power of evidence and the interconnectedness of the community, especially when it comes to disease.

[Amy · Rating 4 out of 5]

Illustrations are spot on for the time period of this tale (1854) and the story is relayed well for young readers. Sure to spark more interest in medical mysteries and the scientific method. I appreciate the extra info at the back of the book.

I'd love to see a series of these, including a story on Ignaz Semmelweis, though that would prove a little tougher since he was ridiculed, fired, and committed to an asylum for his proposition that handwashing/disinfecting hands drastically cuts the maternal mortality rate.

[Rachel · Rating 4 out of 5]

A wonderfully told nonfic about the discovery that Cholera comes from bad drinking water, not the air. It is written almost like a story, with short sentences and a plot that drives the reader to want to know what Dr. John Snow did to find the cause of the disease. I think older elementary students would like this..does still feel very relevant as COVID is still fresh to everyone, and pandemics are still topical.

[Joan · Rating 3 out of 5]

I was rather disappointed by this, mostly due to expecting excellence from Hopkinson. However, I do think one more sentence to the picture book would have helped greatly. Simply adding that Cholera cases decreased or stopped after the handle was removed would have finished the picture book part off properly. Otherwise, I found this pretty good. I wish the print had been larger but I suppose the target audience of middle graders wouldn’t care.

[Jenny · Rating 4 out of 5]

For years, doctors believed cholera was caused by "bad air". Dr. John Snow was fairy certain that it was caused by contaminated water, but he needed evidence. He searched for clues, interviewed those who got sick and neighbors who didn't, tracked where the disease was, and finally found some evidence to support his theories. He was able to convince the city to remove the handle to the Broad Street pump, helping to prevent further spread of disease.

[Kristen M. · Rating 4 out of 5]

This nonfiction science picture book about the great Dr John Snow, father of epidemiology features the 1854 outbreak of cholera in London, England. At that time, folks thought that bad air was the cause of cholera, and not a water-borne disease. Dr. Snow removed the handle of the Broad Street public water pump and ended the outbreak! Excellent introduction to the topic.

[Alice · Rating 4 out of 5]

I enjoyed this book and it reminds me of another Deborah Hopkinson book It is fiction but based in a lot of facts. It is called "The Great Escape" I was surprised she didn't reference this book in the book Evidence! But she does reference her other book 'The Deadliest Disease: Then and Now" and of course Jim Murphy (R.I.P.- Met him once, great man!) "An American Plague"

[Amy · Rating 4 out of 5]

This non-fiction picture book about Dr. John Snow's relentless search to find the source of a cholera outbreak in London during 1854 is fascinating. He was determined to prove that cholera was not an airborne disease, as everyone believed, but actually a waterborne disease. It includes mystery, scientific investigation, and one account from the life of a fantastic doctor and scientist.

[Karen · Rating 5 out of 5]

I love reading nonfiction accounts by Deborah Hopkinson and this nonfiction picture book is perfect. Not only is it visually appealing, it is an accessible introduction to scientific research and infectious diseases.

[Kelly]

I think it's good that Hopkinson pointed out the parts of the story that we can only imagine/guess about. But still, she was able to make a lot of it real. I knew what was coming because I know of cholera, but I think it is good for kids.

[Alice · Rating 4 out of 5]

4 stars
Simplistic story of how John Snow traced a cholera outbreak to the source and had the city of London remove the pump handle in order to stop the spread. Curious to see if intended audience appreciates the story

[Melinda Bender · Rating 4 out of 5]

An outbreak of cholera has occurred in London and Dr. John Snow is determined to find out where it came from. Suspecting it’s from water he begins an investigation. Interesting story how diseases were discovered without today’s technology.

[Abbigail · Rating 5 out of 5]

A thrilling nonfiction picture book about the spread of disease and the mystery of solving it. I use thrilling very intentionally-- I had to know how this book ended and I think kids will feel the same way. A great addition to shelves about medicine, health, and history. Great backmatter too.

[Cheryl · Rating 4 out of 5]

Very clearly written, and back matter enhances. I'm not crazy about the art but it fits and helps to explain the text. Recommended for all of us who need to do be reminded how science works, and for students working in STEM, of course.

[Emily · Rating 4 out of 5]

The dreaded cholera vs. Dr. John Snow. Epidemiology is fascinating, and many consider him the father of the field. I think that books like these do such a great job of teaching history, and I'm grateful that my library is full of them.