Definitive evidence that Napoleon did not die of arsenic poisoning is published today.
After nearly 200 years of debate about what killed the French emperor, researchers at Italy's National Institute of Nuclear Physics (INFN) have examined his hair to shed light on the suggestion that he was poisoned by guards during his exile in Saint Helena, an island in the South Atlantic, following the Battle of Waterloo.
In 1961, an elevated level of arsenic was found in Napoleon's hair, inspiring widespread rumours about the cause of his demise. But his autopsy revealed no telltale signs of poisoning. Now a new study has concluded there was no significant increase in arsenic levels in his last years.
Drs Ettore Fiorini and Ezio Previtali of INFN, who did the study with Angela Santagostino of the University of Milan at a small nuclear reactor at the University of Pavia, will publish their findings in the journal "Il Nuovo Saggiatore".
The team compared samples held by French and Italian museums, dating from when Napoleon was a boy in Corsica; during his exile on the Island of Elba; on the day of his death (May 5, 1821) on the Island of Saint Helena; and the day after his death.
Samples taken from the King of Rome (Napoleon's son) in the years 1812, 1816, 1821, and 1826, and samples from the Empress Josephine, collected upon her death in 1814, were also analysed, along with hair from 10 people today.
The hairs were studied using "neutron activation", a test which does not destroy samples and provides extremely precise results, even for small samples. In the intense radiation within the reactor, elements in the hair are made radioactive and, from the resulting spectrum of radioactivity, its composition can be deduced.
All the hair samples contained traces of arsenic but the samples from 200 years ago contained up to 100 times more than those from today: Napoleon's hair had an average arsenic level of around ten parts per million whereas the arsenic level in the hair samples from today was around one tenth of a part per one million.
But the levels in Napoleon's hair were typical of those seen at the beginning of the 19th people and, significantly, the arsenic levels when Napoleon was a boy and during his final days in Saint Helena were similar.
The work provides indirect support for the suggestion that Napoleon died of stomach cancer linked to a poor diet, published in the journal Nature Clinical Practice Gastroenterology by Dr Robert Genta and colleagues. His risk of cancer might have been increased by his diet of salt-preserved foods which lacked in fruits and vegetables - common fare during long military campaigns.
Napoleon conquered much of Europe, but was ultimately defeated at the Battle of Waterloo in 1815. The British then exiled him to St Helena. He died on May 5, 1821, at the age of 51.