When Bonaparte found himself forced to raise the siege of the fortress at Saint-Jean-d'Acre on 21 May 1799, he demanded that the medical staff evacuate the wounded and ill and kill the plague cases with fatally strong doses of opium, but Desgenettes determinedly refused to do so, forcing Bonaparte to instead transport them as far as Jaffa. The two men's friendship then cooled again over the question of evacuating the plague cases from Jaffa.