Victorian nurse Florence Nightingale (played in this episode by her distant cousin Helena Bonham Carter) is a hero of modern medicine - but her greatest contribution to combating disease and death resulted from the vivid graphs she made to back her public health campaigns. Her charts convinced the great and the good that deaths due to filth and poor sanitation could be averted - saving countless lives. But did Nightingale open Pandora's Box, showing that graphs persuade, whether or not they depict reality?

Cautionary Tales is a podcast by Tim Harford from Pushkin Industries.

You can read more about the remarkable legacy of Florence Nightingale and the perils of misinformation in Tim Harford's new book The Data Detective (US/Canada) / How To Make The World Add Up (UK / International).