On bloodletting - as a healing practice - and how the practice would dictate restrictions to one's diet for a time. Also, precautions that a Jew must take in a non-Jew's barber shop (or salon), beginning with watching the barber in the mirror. Including the question of how the mirror helps in a private domain. Plus, a story that illustrates the danger of a haircut in a private domain. Also, a new mishnah! With a list of the items from non-Jews that Jews are not permitted to use, from wine to Hadrianic earthenware to fish stew to cheese that is produced in a setting of idolatry (the Gemara explains these details later, of course).