Gas

A Gas-Block is a semi-transparent block that floats around.

A gas block can apply various potion effects to those who walk into it with their head.

Toxic Gas (from Gas Machine)
Poison II, Nausea I

Sleep Gas (Toxic Gas + Rose)
Mining Fatigue III, Slowness III

Berserker Gas (Toxic Gas + Fire Charge)
Weakness I, Strength II

Hyper Gas (Toxic Gas + Sugar)
Speed II, Strength I, Jump Boost II

Carbon Gas (Toxic Gas + Coal)
Blindness I, Drowning damage over time.

Explosive Gas (Toxic Gas + Gunpowder)
Poison I, can explode when near a fire source.