1. A disintegrated fetus is not metamei because it is בטל ברוב

On the previous Daf, Rebbe Eliezer ben Yaakov said that a חררת דם – cake of blood discharged by a large animal must be buried, and the animal is exempt from bechor laws, because the חררת דם presumably contains a dissolved fetus. The Gemara asks that if so, it should be metamei like a נבילה, and Rebbe Chiya taught that it is not!? Rebbe Yochanan answered: משום ביטול ברוב נגעו בה – it is because of nullification through majority which [the Sages] applied to it. Meaning, the dissolved fetus is nullified by the majority of the mother’s blood and other discharges, and is not metamei. Rebbe Yochanan said that Rebbe Shimon holds the same view. In a Mishnah, the Tanna Kamma says: השליא בבית – if an afterbirth expelled by a woman is in a house, the house’s contents are tamei through sharing an אהל with a dead fetus. This is not because the afterbirth is itself a fetus; אלא שאין שליא בלא ולד – rather, because there is no afterbirth without a child. Although it is dissolved and nullified, it may have been intact when it emerged. Rebbe Shimon says: ולד נימוק עד שלא יצא – the child already disintegrated before it emerged, so the house is not tamei.

1. Tamei ציר can become tahor through השקה, but not for using in a pot

Rebbe Yehudah Nesiah said that if one purchased ציר – fish brine from an עם הארץ, which is presumed tamei, משיקו במים וטהור – he can bring it into contact with [mikveh] water, and it is then tahor, regardless of its proportions: if the water is the majority, which nullified the fish juice and made the brine susceptible to tumah, then once he performs השקה with the mikveh water, it becomes tahor. If the fish juices are the majority (so השקה would be ineffective), it was never capable of contracting tumah in the first place. Although there is water in the mixture, the water is בטל in the fish juice. Rebbe Yirmiyah said that this method is only effective לטבול בהן פיתו – to dip his bread into [the brine], which is now considered tahor. But it is not effective לקדירה – to use for seasoning a pot of food with this brine, because we say מצא מין את מינו וניעור – a type has found its own type and was “awakened,” i.e., the water content in the ציר joins with the water in the pot to become the majority, and regains its capacity to be metamei.

1. Tahor chullin in which tamei terumah became בטל

Abaye objected to Rebbe Yirmiyah’s ruling: וכי טומאה שבטלה חזרה וניעורה – but can tumah which was already nullified be reawakened?! Rav Dimi sought to prove that it can, from a Mishnah about a סאה of tamei terumah which fell into one hundred סאה of tahor chullin (which had never been susceptible to tumah). Rebbe Eliezer says: תירום ותרקב – [a סאה] is removed and left to rot, because we say that the סאה which fell in is the very סאה which came up, and cannot be eaten. The Chochomim say: תעלה – [the סאה] is nullified, and may be eaten together with the mixture. The entire mixture must be eaten dried, or toasted, or kneaded with fruit juices, or divided into doughs which contain less than a כביצה of tamei terumah in one place. This ensures that the chullin will not become tamei. [Rebbe Eliezer agrees with this requirement.] This restriction was enacted in case more tamei chullin would later be added and combine with the tamei terumah, because nullified tumah can be “reawakened”!? Abaye answers that although adding tamei produce can reawaken nullified tumah, adding tahor produce cannot.