Blackmouth Oil

Blackmouth Oil is an alchemical component for the creation of various action-related potions.

Gnomes like to use Blackmouth Oil as a lubricant for their machinery, especially springs. It is also noted to be extremely flammable.

Source
Blackmouth Oil is crafted with Alchemy (80); taught by Alchemy trainers.

Alchemy

 * Elixir of Water Breathing
 * Swim Speed Potion
 * Free Action Potion

Enchanting

 * Fishing (enchant)