Kelim, Chapter Nineteen, Mishnah Seven
1) A box whose opening is at the top is susceptible to corpse uncleanness.
2) If a piece fell out above it is still susceptible to corpse uncleanness.
3) If it was damaged below, it becomes clean.
4) The compartments within it remain unclean and are not regarded as a connected to it.
Section one: If a box has an opening on its top it is susceptible to corpse uncleanness, and to other types of uncleanness as well. The only type of impurity to which it is not susceptible is midras impurity, because midras impurity is imparted only to objects that are meant for sitting.
Section two: If the box broke but only at its top, it is still usable so it is still susceptible to impurity.
Section three: However, if it was damaged below it is no longer usable so it becomes clean.
Section four: If the box had compartments and the box became clean because it was broken, the compartments are still usable so they remain unclean. They are not considered as connected to the box, for it is clean and they are unclean.