Kelim, Chapter Twenty-Two, Mishnah Ten
1) A toilet is subject to both midras and corpse uncleanness.
a) If the leather seat was separated, the leather is subject to midras uncleanness and the iron is subject only to corpse uncleanness.
2) A folding stool whose cover is of leather is subject to both midras and corpse uncleanness.
a) If it was taken apart, the leather is subject to midras uncleanness while the stool is altogether clean.
3) A bath-house bench that has two wooden legs is susceptible to uncleanness.
a) If one leg was of wood and the other of stone it is clean.
4) Boards in a bath-house which were joined together:
a) Rabbi Akiva says that they are susceptible to [midras] uncleanness;
b) But the sages say that they are clean, since they are made only for the water to flow under them.
5) A fumigation-cage that contains a receptacle for garments is susceptible to uncleanness,
a) But one that is made like a bee-hive is clean.
Section one: The toilet described here is made of a leather seat and an iron base. When it is whole, the entire toilet is subject to both midras and corpse uncleanness, because it is a seat and it is a vessel. If the leather seat is removed, the seat is still subject to midras uncleanness because it is still usable as a seat. But the iron base can no longer be sat upon, and therefore it is subject only to corpse uncleanness, because it is still a vessel.
Section two: When the leather cover is part of the stool, the entire stool is subject to both midras and corpse uncleanness. If the cover is removed, it remains susceptible to midras uncleanness, but the remainder of the stool cannot be used so it is clean.
Section three: The bench is made of stone which is not susceptible to impurity. However, if both of its legs are made of wood, the entire bench becomes susceptible on account of the legs. If only one leg is made of wood and the other is made of stone, the bench is still clean.
Section four: In a bath-house, there would be seats made of wood joined together for the bathers to sit on. According to Rabbi Akiva, since people sit on these seats, they are susceptible to impurity. The sages disagree because they see the function of the seats as just letting dirty water already used by others to pass beneath. In other words, people don’t want to sit on the seats; they just want to avoid something else.
Section five: A fumigation cage is a vessel into which fire and sulfur are put to fumigate the clothing that would be put above. If it has a receptacle in which to put the clothing, it is susceptible to impurity. But if it is made in the shape of a bee-hive and does not have a receptacle, it cannot become impure.