*EDIT
** If the user of explosion potions has any alchemy skill the damage will be increased by 1 for every 5 points of alchemy skill the user has. The effects of Enhance Potion items are also added to explosion potions. Explosion potions cannot be used if you are [frozen].
*** If the user of conflagration potions has any alchemy skill the damage will be increased by 1 for every 13 points of alchemy skill the user has. The effects of Enhance Potion items are also added to conflagration potions.
**** If the user of invisibility potions has any alchemy skill the duration will be increased by 1 for every 10 points of alchemy skill the user has. The effects of Enhance Potion items are also added to invisibility potions.