I was searching for the white-stone, and had just ran out of saws. I was next to one othe 4 possible tress left where the whitestone could be, when the leviathan attacked me. I ran, and escaped to the tree! It had the whitestone under it. I had no saws, and it was a non-petrified tree. My amount of magic saws was -1. Afterwards I had an endless supply of magic saws. I could even use them against the Leviathan. Every time I had to use a magic saw it just substracted one from the counter. When I got a saw it still added to the counter. In the end I finished the game with about -50 of them.