Château de Malmaison
Davy's party did not meet Napoleon in person, but they did visit the Empress Joséphine de Beauharnais at the Château de Malmaison. The party left Paris in December 1813, travelling south to Italy. They sojourned in Florence, where using the burning glass of the Grand Duke of Tuscany in a series of experiments conducted with Faraday's assistance, Davy succeeded in using the sun's rays to ignite diamond, proving it is composed of pure carbon.