Quotation על שבת 214:9

They stated three things before Rabbi Yishmael, and he pronounced none of them either unlawful or lawful; and Rabbi Joshua ben Matya explained them.One who lances an abscess on the Sabbath: if it was to make an opening he is liable; if it was to bring out the pus, he is exempt. And concerning one who hunts a snake on the Sabbath: that if he was occupied with it in order that it should not bite him, he is innocent; but if that he might use it as a remedy, he is guilty. And concerning Ironian stewpots: that they do not contract impurity when under the same tent as a corpse; but become impure if they are carried by a zav. Rabbi Eliezer ben Zadok says: “Even if they are carried by a zav they remain pure, because they are unfinished.”