Great idea, but shouldn\'t you have to throw 2 vials, or a vial and some material, so they can react? would be sort of a bummer if the lid on your Alchemist\'s Fire potion slid off in your bag, and it got a chance to react with air (assuming the liquid does react with air, since there is only one vial to be thrown), suddenly we have a Screaming Alchemist On Fire.
EDIT: Also, this would open up for some interesting traps O.o