Cauldron

The Cauldron is a future craftable essential block in Minecraft. It will be used to brew Potions.

History
Alchemy was first hinted at in July 2010, when Notch explained why redstone ore disintegrates into "dust". He states that dust will be used later in potions. Potion effects were introduced in Beta 1.8, and expanded on in the Beta 1.9 Pre-release.

Jeb later tweeted about issues with the current implementation of cauldrons.