People and utensils [both] become tamei from a corpse. People have a stringency that utensils do not have, and utensils have [a stringency] that people do not have. [When a] utensil [touches a corpse,] three [utensils will become tamei in turn after the first utensil touches a corpse], whereas [when] a person [becomes tamei by touching a corpse, only] two [will become tamei]. People have a stringency [that utensils do not have]: When a person is in the middle, there can be four [persons and utensils that become tamei in succession], but when there is no person in the middle, there can be only three [stages of con-tact].

People and clothing [both] become tamei from a zav. People have a stringency that clothing does not have, and clothing [has a stringency] that people do not have. A person who touches a zav renders clothing tamei, whereas clothing that touches a zav does not render [other] clothing tamei. Clothing has a stringency [that people do not have]: Clothing that ‘‘carries’’ a zav renders a person tamei, whereas a person who carries a zav does not render [another] person tamei.

A person does not convey [corpse-] tumah until his soul departs, even if he is fatally wounded or even if he is moribund. [Similarly,] he [still] binds [his dead brother’s wife] for yibum, releases [her] from yibum, entitles [his wife] to eat terumah, and disqualifies [her] from [eating] te-rumah. Similarly, domesticated and wild animals do not convey tumah until they have died. [If] their heads were severed, they are tamei, even if they are [still] moving convulsively; [the movements are] like the [severed] tail of a lizard that is moving convulsively.

Limbs have no [minimum] size. Even [a limb] of a corpse smaller than an olive, or [a limb] of a carcass smaller than an olive, or [a limb] of a sheretz smaller than a lentil convey their tumah.

There are two hundred and forty-eight limbs in a person: thirty in the foot — six per toe, ten in the ankle, two in the leg, five in the knee, one in the thigh, three in the hip, eleven ribs, thirty in the hand — six per finger, two in the forearm, and two in the elbow, one in the upper arm, and four in the shoulder — [for a subtotal of] one hun-dred and one on one side and one hundred and one on the other; [plus] eighteen vertebrae in the spine, nine in the head, eight in the neck, six in the chest, and five in the genitals. Each [of these limbs] conveys tumah via touching, carrying, or ohel. When is this so? When it contains sufficient flesh [to heal]. But if [the limb] does not contain sufficient flesh [to heal], it conveys tumah via touching or carrying, but not via ohel.

These convey tumah through ohel: a corpse; an olive’s volume of a corpse; an olive’s volume of netzel; a ladleful of corpse-powder; the spine and the skull; a limb [sev-ered] from a corpse and a limb [severed] from a living body that have sufficient flesh [to heal]; a quarter [-kav] of bones [even if it is] less than most of the frame or less than the numerical majority; most of the [skeletal] frame or a numerical majority [of the bones] of a corpse, even if it comprises less than a quarter [-kav of bones]. [All of these] convey tumah. How many bones are a numerical majority [of the bones in the skeleton]? One hundred and twenty-five.

A quarter [-log] of blood and a quarter [-log] of death blood [convey tumah] if they are from one corpse. R’ Akiva says: [Even] from two corpses. If all the blood of an embryo emanated, R’ Akiva says: [Even] a tiny amount [conveys tumah]; whereas the Sages say: [Only if there is] a quarter [-log]. An olive’s volume of worms, whether alive or dead — R’ Eliezer declares it tamei like the flesh [of a corpse], but the Sages declare [it] tahor. The ash of cremated corpses — R’ Eliezer says: Its [minimum] measure [to convey tumah] is a quarter [-kav of ash], but the Sages declare it tahor. A little more than a ladleful of grave powder is tamei. R’ Shimon declares it ta-hor. A ladleful of corpse powder that was kneaded with water is not [considered] connected in respect to tumah.

These convey tumah via touch or carrying, but do not convey tumah via ohel: a bone the size of a barleycorn; the land of the nations; a field in which a grave was plowed over; a limb [severed] from a corpse or a limb [severed] from a living body that is lacking sufficient flesh [to heal]; [and] a spine and a skull that are incomplete. How much is considered ‘‘missing’’ in the spine [for it to be considered incom-plete]? Beis Shammai says: Two vertebrae. But Beis Hillel says: Even one vertebra. And of the skull? Beis Shammai says: As [large as the hole] made by a gimlet. But Beis Hillel says: An amount which, if removed from a living person, would cause him to die. Which gimlet are they referring to? The small one used by physicians — these are the words of R’ Meir. But the Sages say: The large gimlet of the [Temple] chamber.

The cover of a grave and its support convey tumah if touched and through ohel, but not if they are carried. R’ Eliezer says: They do convey tumah if they are carried. R’ Yehoshua says: If underneath them there is earth from the graves, they convey tu-mah when carried, and if not, they do not convey tumah when carried. What is a support? That upon which the cover [itself] rests. However, a sup- port for a support is tahor.

These items are tahor if they become diminished: an olive’s volume of a corpse; an olive’s volume of netzel; a ladleful of corpse powder; a quarter [-log] of blood; a bone the size of a barleycorn; and a limb, [that was severed] from a living person, whose bone is incomplete.

A spine and a skull from two corpses; a quarter [-log] of blood from two corpses; a quarter [-kav] of bones from two corpses; a ‘‘limb’’ [severed] from two corpses; and a ‘‘limb’’ [severed] from two living persons — R’ Akiva declares [all these cases] tamei, but the Sages declare [them] tahor [from tumas ohel].

A bone the size of a barleycorn that was divided into two — R’ Akiva rules it tamei, but R’ Yochanan ben Nuri rules it tahor. R’ Yochanan ben Nuri said: They did not say, ‘‘Bones the size of a barleycorn.’’ Rather [they said], ‘‘A bone the size of a barley-corn.’’ A quarter [-kav] of bones that was crushed so that no bone is the size of a barleycorn — R’ Shimon rules [it] tahor, but the Sages rule [it] tamei. A limb [severed] from a living person, that was divided into two, is tahor. R’ Yosi declares it tamei, but he agrees that if [the limb] was removed [from the living person] half at a time, it is tahor.