Townspeople crowd around to buy the bottles, sold for a dollar each (members of Rawley's Black community stand aside, frustrated and envious, as they can't afford to pay that price).
At first he takes her for a middle-aged matron and replies to her overtures with what are clearly his standard words of praise, prepared for all female customers; he then begins to truly look at her for the first time, and he and the reader learn that Effie is only about thirty and of at least average looks.
Soon, he gives her the second bottle free and proceeds to close down his stall for the afternoon (it has grown quite hot outside and few new customers are arriving), gallantly offering to escort her home.
Discovering his sister in this compromising position, Burke places his hand on the pearl handle of his gun and angrily demands to know the Professor's intentions.
Though it is not explicitly stated, the ending gives the clear impression of a deliberate badger game planned in advance by brother and sister in order to get Effie a husband.