On: Most Execrable and Abominable or Irreligious: When...

[Mistletoe]

I can't make heads or tails of this. The poison was -

https://en.wikipedia.org/wiki/Pseudaconitine from the Monkshood.

But what was in Caravita's Oil and did it even work or was it just chance that the prisoner lived? Google isn't much help as it all leads back to this same book.

[woadwarrior01 → Mistletoe]

Most likely, an early instance of snake oil.