I have never been able to track the movie this scene came from down but the scene itself really stuck with me. I saw this movie on the local Friday night “horror movie host” show when I was just a kid so that would have been in the late 1960’s – say 68-70.  I believe the film was black and white.  The scene showed a guy being lured into a tent at a carnival (by a female fortune teller?) and then being poisoned by her – the shot I remember was from the victim’s point of view as the vial came nearer and nearer his mouth.   Affected me enough so that to this day I have never done a shot in a bar where someone else is pouring something into my mouth, and I’m in my mid fifties.  Any possible suggestions as to titles would help!