The writer reflects on their personal struggles with ill health and likens their ongoing battle with nature to Don Quixote’s quest. They express deep appreciation for the recipient’s work, which has provided valuable insights, particularly regarding the origins of smallpox and its comparison to leprosy. The writer acknowledges the superiority of eradication over inoculation but doubts Europe’s ability to collectively address these health crises. They lament the lack of focus on public health issues in Paris, noting the city’s poor sanitary conditions and the general apathy towards significant reform.