If you possess a Cenarion beacon while mining in Felwood, you will be able to see tainted vitriol that corrupts a vein of raw metal. I know how to purify that vitriol and turn it into a reagent that goes into making Cenarion plant salve. You will then use that salve on plants you find in the wild that need saving.$B$BIf you have collected any tainted vitriol, I'll give you some Cenarion plant salve I have already prepared.