“Cursed hebanon.”
The jury is out on this one…
Two main theories exist about what “hebanon” could be, since it isn’t an identifiable substance as far as we know.
The first theory is that it could be Taxus baccata, or “yew”.
Here are the effects of ingesting yew:
“The action of the poison is extremely rapid because taxin is quickly absorbed in the digestive system. It is a very poisonous cardiovascular toxic substance and causes vomiting and abdominal pains, painful diarrhoea, dilated pupils, pallor, collapse, cramps, unconsciousness, and death due to cardiac arrest and respiratory failure often within an hour following ingestion.” Thanks to The-Tree.org.uk, here.
That doesn’t sound right to me.
The second is that hebanon is Hyoscyamus niger, or “henbane”.
Here’s what it does to you:
“You should notice your skin turning red, dry mouth, an irregular heartbeat, and enlarged pupils. As it gets worse you’ll feel sleepy, then restless, hallucinate, experience hyperactivity, and finally fall asleep.” Take too much and you die, of course. That nice description comes from the science project of Caitlin Baker, here.
I’m a fan of this conjecture, especially since it is not fast-acting, and the symptoms vary depending on dosage (which could account for the various effects on Gertrude, Laertes, Hamlet, and Hamlet Sr.).
You suggest (last paragraph above) that Gertrude, Laertes, Hamlet, and Hamlet Sr. (why omit Claudius?) all died from doses of hebanon. Actually it was only Hamlet’s father. As he slept in his orchard, Claudius ‘in the porches of [his] ears did pour’ the ‘leperous distilment.’
There is no evidence that the ‘union’(also baffling to critics) Claudius threw into the wine chalice and the ‘unction’ Laertes bought ‘of a mountebank’ and used to ‘anoint his sword’ were also hebanon.
Points well taken. My omission of Claudius was accidental, and as for why I lumped them together, I was posting the information for the cast.
The director decided, for the sake of continuity in the physical response as all of the characters died, that it was the same poison. As you suggest there’s no reason to assume, based on dramaturgical evidence, that Shakespeare intended that continuity.