An old-looking glass flask with a piece of wood hanging from it by a worn old rope. The piece of wood is smooth and looks like it was put there to be used as a label. Whenever something is written on the wood is “absorbs” into the wood in a few minutes… This item was created as part of a test to gain entrance to a prestigious academy of Wizards that was shut down after a mysterious fire. This flask was nowhere to be seen after the fire.
When the flask is empty and anything is written on the piece of wood it “absorbs” within a few minutes.
However, if there is a liquid in the flask and the name of another liquid is written on the wood the current liquid turns into the liquid written on the wood (the name of the liquid remains on the wood until the flask is empty again)and functions as if it were the new liquid.
If the flask and piece of wood are not linked to each other in some way all magic is lost from this item.
This item is usable only three times a week. After the third use in one week treat it as if the piece of wood were removed.
Optional Idea: any time this item is used to create a healing or resurection type potion the one who wrote on the piece of wood feels light headed and can think straight for a few days.