Evidence! How Dr. John Snow Solved the Mystery of Cholera by Deborah Hopkinson. Illustrated by Nik Henderson. Alfred A. Knopf, 2024.

I read an adult nonfiction book called Ghost Map by Steven Johnson, about Dr. John Snow and the 19th century London cholera outbreak associated with the Broad Street water pump. So, I knew the basic outlines of this picture book story by noted author Deborah Hopkinson. Still, it was good to be reminded that the solution of medical mysteries has always required dogged work and investigation to find evidence that will pinpoint the source of diseases and lead to treatments and a cure.

When cholera came to Broad Street and surrounding areas in London in 1854, the prevailing theory was that the disease was caused and spread by “bad air.” Dr. Snow, who had already been researching the disease of cholera for some time, believed that cholera was spread by sewage-contaminated water. This book tells the story of exactly how Dr. Snow proves his hypothesis and stops the Broad Street cholera epidemic from continuing to kill London’s tenement dwellers..

The text of this story is simple but detailed enough to make the story clear to young readers. Step-by-step, Ms. Hopkinson leads us through the thought processes of Dr. Snow as he asks questions and interviews people to test his hypothesis and to eventually show the people of the Broad Street neighborhood what they must do to stop the cholera outbreak.

The illustrations in the book by Nik Henderson are adequate, depicting a foggy, Dickensian London with Dr. Snow moving quickly and confidently through each picture on a quest to find the answers to the cholera problem. The appendices include a brief restating of “the case against the Broad Street pump”, a short biographical sketch of Dr. Snow, a list of major infectious diseases and their causes, and a list of books and internet resources for adults and children about cholera and other infectious disease epidemics.

This post here at Semicolon, called Epidemic, Pandemic, Plague and Disease in Children’s Books, could be helpful for those who want to pursue the subject further.