Evidence: How Dr. John Snow Solved the Mystery of Cholera. Written by Deborah Hopkinson and illustrated by Nik Henderson. Alfred A. Knopf, penguin Random House. 2024. $26.99 ages 7 and up

 

"John has seen that cholera causes horrible 
stomach problems - vomiting and diarrhea. 
That's led him to believe something people 
swallow is making them sick. But what? 

John has also noticed that cholera doesn't 
affect whole cities at once. It breaks out in 
clusters, bubbling up like blisters. John 
wants to know: What links these cases 
together?" 

It's a hot autumn day in London in the year 1854. Broad Street looks like many other streets in the city: yellow smoke, horse dung on the roads, and sewage and human waste 'in yards and cellars'. The people are thirsty and must wait in line to fill a pail of water for their families. They all use the Broad Street pump. Annie Lewis is but one of the people lined up. Her family lives in a single room in a rooming house that offers no access to water. 

In that week, one of the roomers gets sick and dies. The news of his death and the sickness that caused it spreads quickly. The dreaded diagnosis is cholera. There is no cure, and no stopping it. Doctors are convinced that the smell is what is causing the disease to spread. Not so for Dr. John Snow. His visit to Broad Street is not about the patients. John Snow is looking for clues to what is causing the spread of this frightening disease. 

He is an investigator. He has been tracking cholera's spread for years, always searching fpr an answer to its origins. He knows its symptoms and is convinced it is something people ingest that is making them sick. He wants to know what that is. It is distressing that so many people on Broad Street are sick. It can't be that they all ate the same food. Can it be the water? 

He is determined to get the evidence he needs to explain how it spreads. It takes long hours, many interviews, and much fact gathering. With careful research and hard work, John is finally able to find the proof needed to convince the neighborhood council that he now knows the root cause. It is the only hope the people of Broad Street have for saving lives. They agree to take the handle from their pump - all thanks to the evidence John collected. 

Back matter includes The Case Against the Broad Street Pump, further information about John Snow, a list of major infectious diseases and what caused them, and resources for further learning.