Further to the above, when I looked up the terms Mithridate and Treacle, I was led to articles about ancient "cure all" remedies. Mithridate was called an antidote against all poisons, named after a king who, reportedly, used his prisoners as experimental guinea pigs while perfecting the complicated formula containing 64 ingredients of animal, vegetable and mineral origin. Treacle (or more properly "Venetian Treacle") was a name English apothecaries in R Turner's time would have given to a similar cure-all remedy known as Theriac. Like Mithridate, it contained many expensive ingredients and took a long time to mature to full potency, and was therefore a luxury item sought after by the rich.

Here is a fascinating paper entitled: "Venetian treacle and the foundation of medicines regulation", J. P. Griffin, British Journal of Clinical Pharmacology, 2004.
https://sci-hub.se/https://doi.org/10.1111/j.1365-2125.2004.02147.x