Retain Essence (Su)Edit
At 5th level, an artificer gains the ability to salvage the XP from a magic item and use those points to create another magic item. The artificer must spend a day with the item, and he must also have the appropriate item creation feat for the item he is salvaging.
After one day, the item is destroyed and the artificer adds the XP it took to create the item to his craft reserve. These points are lost if the artificer does not use them before gaining his next level.
For example, an artificer wants to retain the essence of a wand of summon monster IV that has 20 charges. Originally created (like all wands) with 50 charges, it required 840 XP when initially made, or 16.8 XP (840 - 50) per charge. The artificer is able to recover the XP from the remaining charges. He puts 336 XP (16.8 X 20) into his craft reserve.