[If] one sold wine or oil to another, and it appreciated or depreciated, if [it happened] before the measure was filled, [it belongs] to the seller; once the measure was filled, [it belongs] to the seller; once the measure was filled, [it belongs] to the buyer. If there was a middleman between them, [and] the barrel broke, it broke for the middleman.  He is obligated to let three drops drip out for him. [If] he turned it over and drained [it], it belongs to the seller. A storekeeper, however, is not obligated to let three drops drip out. R' Yehudah says: Only on the eve of the Sabbath, at dusk, is he exempt.