Due to his work to determine how cholera was spread in the 18th century, John Snow (1813 1858) has been hailed as the father of modern epidemiology. In addition to his work in epidemiology, Snow was also a famous physician and a leading pioneer in the development of anesthesia. As testament to his stature, Snow was recently voted the greatest doctor of all time in a poll by England's Hospital Doctor newspaper (Grant 2003). That is high praise indeed, but how can and how should the life and work of an 18th-century English doctor influence biology teaching in 21st-century secondary schools?
This article presents an inquiry model, The Life and Work of John Snow, which teachers can use to develop a series of biology lessons involving the history and nature of science. The lessons presented use a combination of literature, history, critical thinking, and simulation to promote "the use of history in school science programs to clarify different aspects of scientific inquiry, the human aspects of science, and the role that science has played in the development of various cultures" as recommended by the National Science Education Standards (NRC 1996, p. 107). In this article, the model is presented in four parts: the effects and occurrence of cholera; the context (environment) in which Snow worked; Snow's character and work involving cholera; and a simulation representing the spread of disease. Depending on the amount of time available in your science program, and the depth to which you pursue some of the issues, two to three days would be an adequate amount of time to complete the lessons.
Part one: Cholera
We begin The Life and Work of John Snow by providing students with a brief background on cholera including the causes, effects, occurrence, and treatment of the disease. Depending on the age of your students, this information can be either presented by the teacher or a focus of student research. The Centers for Disease Control and Prevention (CDC) provides comprehensive information about cholera (see "On the web" at the end of this article), which we use in presenting the disease background. While the present-day risk of contracting cholera in North America has been greatly reduced, waterborne diseases such as cholera are still potential threats, as demonstrated by Hurricane Katrina in 2005. Outside of the United States, in Africa, Asia, and Latin America, cholera remains a serious health issue. Aside from the information acquired from the CDC website, media reports of disease outbreaks can be used to connect the science classroom with the broader world. Once students are familiar with current information about cholera, we visit the past and the social and scientific environment in which Snow worked.
Part two: London and miasma
The appalling social conditions in London in the mid-18th century were vividly described in the works of Charles Dickens and in the newspapers of the day. On September 24, 1849, for instance, a journalist reported on a visit to the London district of Bermondsey, "In No. 1 of this street the cholera first appeared 17 years ago, and spread up it with fearful virulence; but this year it appeared at the opposite end, and ran down it with like severity ..." (Mayhew 1849). At that time, cholera was a major reason for the highest death rate in Britain's cities since the Black Death. More information on social conditions at the time can be found in the online article "London's 'great stink' and Victorian urban planning" (Daunton 2004). This material provides excellent background reading for students.
In the mid-18th century, cholera and other diseases were thought to be caused by miasma, a poisonous, airborne, foul-smelling vapor filled with particles of decomposing material. The miasmatic theory of disease was strongly supported by the doctors of the time, unsurprising given the correlation of cholera with the foul-smelling waters described by Mayhew (1849). …