Thanks so much for the excellent responses guys! as always wonderfully dimensional perspective and ideas. After reading these my curiosity compels me further and I found the following which speaks to the notes on the fear of poisoning as well as which might have been used.
From "The Advance and the Poisoners of Elizabethan Tragedy"
Fredson Bowers
In 'Journal of English and Germanic Philology' 36, (1937) p.491-504
Referenced in "Scandal of Images" Margaret A.Tassi (2005) in notes, p.231
Bowers discusses the use of contact poisons, and that the 'king of Renaissance poisons' was certainly arsenic, often obtained in the form of 'ratsbane' and the ingenious devices for dispensation such as the poisoned knife blade or often ring.
"...regarding Elizabethan fear of poisons he cites Sir Edward Coke, who wrote in 1602 that poison, 'as hath been said, the most horrible and fearful to the nature of man'."
It seems that this clearly much networked reference from the 1937 work as well as reference to the quote from 1602, suggests that poisoning in weapons, though an element of drama , was indeed probably a reality of some presence.
Interesting observations and descriptions concerning the physiological aspects of poisons and how they might have manifested in use, I think we have a pretty good forensics panel here!! Outstanding, compelling, and indeed a bit scary
I think the fears were absolutely well placed.
All best regards,
Jim