Detect Poison

V,S. 1 standard action. 25ft + 5ft/2lvls. One creature, one object, or a 5-ft. cube.
Instantaneous. No Saving Throws. No Spell Resistance.
DC 20 Wisdom/Craft (alchemy) - detect
exact type of poison.
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.