Handwritten letter on vaccination in France, dated October 20, 1809, which appears to be addressed to an authority or scientific correspondent. The author thanks his correspondent for sending him the document, even though it offers nothing new about the method or efficacy of vaccination. He stresses that those who speak of it must defend vaccination with conviction. He stresses the importance of promoting this discovery so that it can spread widely. The author warns against coercive measures to impose vaccination, preferring a more persuasive approach. He also criticizes the ignorance and stubbornness of certain individuals who hinder the spread of vaccination. Good condition, leaf slightly damaged at edge. 1 p., in-4° format. 1809. Historical background: The text refers to smallpox vaccination, which developed in France under Napoleon I following the discoveries of Edward Jenner, introduced in France as early as 1800.