The Halloween Peppermint Incident

Question

https://www.historic-uk.com/HistoryUK/HistoryofBritain/Dying-for-Humbug-the-Bradford-Sweets-Poisoning-1858/

Answer 1

I wonder why the pharmacy (oops, chemist) had so much arsenic on hand?

Was arsenic used in medicines?

Comments

Quite possible.