Library.

“Mercuric chloride has been used historically for various purposes, including as a disinfectant and in the treatment of syphilis, with its use dating back to at least the 18th century.”

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.

“Mercuric chloride (HgCl₂), historically known as corrosive sublimate, is now primarily restricted to laboratory research and industrial catalysis due to its extreme toxicity.”

The claim correctly identifies mercuric chloride's extreme toxicity and the general trend toward restricted use, but overstates how narrow its current applications are. A 2023 New Jersey government hazardous substance fact sheet lists ongoing uses beyond laboratory research and industrial catalysis, including wood preservation, embalming, photography, fabric printing, and disinfection. While these may be declining, their documented presence in authoritative sources undermines the "primarily restricted to" framing.