A new mishnah! One who renders another's produce impure or mixed in ways that it can't be used... Plus, unrecognizable damage - is it tested as damage for payment or not? Also, a talmudic treatment of the dispute between Rabbi Meir and Rabbi Yehudah, over when one is penalized for a violation, for example, of unrecognizable damage, or even Shabbat. And the Gemara's resolution of that apparent contradiction.