Shabbat 80 - Ink and oil
We learned that one transgresses Shabbat if he carries enough ink to write two letters. Whether this ink is an an inkwell (with more ink on the walls) or in a quill, the amount liquid ink must be sufficient for writing the letters. Rava asked, "If he took ink for one letter in a ink-well, and for another letter in a quill, do they combine?" - No one found an answer.
The minimal amount of lime is defined as "enough to smear on a little girl." What does this mean? Rav Yehudah explained, "Jewish daughters who matured but were still young in years and desired to remove unwanted hair: the daughters of the poor would smear themselves with lime; the daughters of the rich would use flour; and the daughters of the kings - would smear themselves with virgin olive oil.
Rabbi Nechemyah gives a larger limit on lime: enough to smear on the "andipi." What is "andipi?" We learn this from the following story. A person from Galilee came to Babylon. They asked him to expound on the deep secrets of "The working of the chariot," and he unhesitatingly agreed. Before he started, however, a hornet emerged from a nearby wall and stung him on the forehead ("andipi"), so that he died. We learn from here that "andipi" is the forehead.
Art: Benjamin Walter Spiers - Art and Letters