Acid Drip

You summon forth a small ever dripping sphere of acid. It cannot be moved. This acid produces one drop per round, or 10 drops per minute. These drops do 1 acid damage to a creature who happens to be underneath it. If it is placed over a non-magical piece of metal, wood, stone, or cloth then it begins to dissolve and corrode that material. These drops dissolve approximately 1 inch of metal a minute, 2 inches of stone in a minute, 3 inches of wood in a minute, and one drop destroys 1 square inch of cloth