A new mishnah! If the blood of an offering were mixed with blood... it is still acceptable as an offering. What if it were mixed with wine? Or if the bloods mingled.... The blood must appear to be blood, at the very least, rather than whatever other liquid it might have mingled with. Plus, the debate over what it means for the blood to be recognizable. And the question of which liquid becomes the majority - whether it's like with like, or different substances, with ramifications for whether the mixture can be used on the altar.