You can channel magical energy into orbs of acid.
Prerequisite(s): Ability to cast 2nd-level spells, Elemental Focus (Earth).
As long as you have an elemental (earth) spell of 2nd level or higher in your known spells and have at least 2 MP in your MP pool, you can throw an orb of acid as a ranged touch attack. The attack has a range of 5 feet per level of the highest-level earth spell you can cast and deals 1d6 points of earth damage per level of that earth spell. As a secondary benefit, you gain a +1 competence bonus to your caster level when casting elemental (earth) spells.