Terms used in negotiating a sale or a price - and how 4 people must be in agreement for a price to apply (though the customary appraisal is by 3 people) - among other cases. Also, a new mishnah! Using a funnel for wine and discovering a drop left over - it makes the whole thing prohibited, in case it was libation wine. With ramifications, of course. Plus, the Gemara on this mishnah addresses how this liquids can mix - and when they are considered blended halakhically, or moistening a solid, and when not.