The Poisoned Chalice
In the poisoned chalice. it is the 3rd episode in series 1 of Merlin.
Merlin - 2008 The Poisoned Chalice 1-4 is rated/received certificates of: Netherlands:9
the moment of truth
It's episode 9 of Season 1: Excalibur
I believe hulu.com has the first two seasons of Merlin that you can watch for free and legally (it gets its money from the commercials it advertises on the site and intermittently throughout the show).
the mark of nimeuh the poisoned chalice excalibur le morte d'arthur
You can watch the last episodes of Merlin on BBC/ITV I Player.
season 3 episode 5
Season 4, episode 6
According to fans and other sources there will be an episode of Merlin at Christmas. whether it will actually be a longer episode or Christmas themed is another matter.
technically no, although he gets poisoned a few times like in episode 13. but he is a human then and poison may not affect him as much or at all whilst he is a half demon.
It's KIRARA. But the alternate saying is Kirara. And it's episode 30-31