André Michaux brought the caillou to France in 1786. This letter, dated 16 October 1800 (or 24 vendémiaire 9) and signed by the Prime Minister Lucien Bonaparte, authorises the purchase of the caillou by the French State: "I have received, Citizens, the letter by which you informed me that Citizen Michaux would cede to the Museum of Antiquities a precious stone he deposited there if the government would grant him the three thousand francs necessary to print the work done by this naturalist in North America on the botany of this region. I accept this proposal."

Letter conserved at the Archives nationales, AJ/15/569 - Dossier Baudin, folios 362 to 365.