The Short Version
The historical record clearly supports this claim. Multiple independent and credible sources — including a peer-reviewed PMC article, PubChem, and the Journal of Military and Veterans' Health — confirm that mercuric chloride (corrosive sublimate) was used as a disinfectant and in syphilis treatment. The 18th-century physician Gerhard van Swieten is specifically documented as introducing it for syphilis therapy, satisfying the claim's temporal threshold. The claim's modest scope is well within what the evidence establishes.