The character determine whether a creature, object, or area has been poisoned or is poisonous. The character can determine the exact type of poison with a successful Wisdom check (DC 20). A character with the Alchemy skill may try an Alchemy check (DC 20) if the Wisdom check fails, or may try the Alchemy check prior to the Wisdom check.
Note: The spell can penetrate barriers, but 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt blocks it.