May 5, 1821. Napoleon Bonaparte, deposed emperor exiled on the island of St. Helena, is about to take his last breath. The son of a Corsican family, he has been close to death on many occasions since, as a young captain in the revolutionary army, he seized Toulon from the royalists in 1793.

The discovery of the transmission of diseases by microbes, and the victorious fight against the pandemics that followed, owe much to the rivalry of Pasteur and Koch.