In Chapter 10, Jem and Scout are walking down the street with their air rifles when they spot an old dog named Tim Johnson walking awkwardly down the road. Jem runs home and tells Calpurnia, the Finch's cook, that Tim Johnson is limping when he walks. Calpurnia goes outside and sees Tim Johnson staggering down the street. She immediately recognizes that the dog has rabies. She runs to the phone and informs Atticus. Then she calls the operator, Eula May, and tells her to call everyone on the street and tell them a "mad dog's comin'." (Lee 124) Calpurnia asks Jem if the Radleys have a phone, and he tells her they don't. Calpurnia runs over to the Radley's front porch and begins to knock on their door. At this moment, Harper Lee portrays the subtle discrimination in the small Southern towns. Scout says to Jem, "She's supposed to go around in back" and Jem says, "Don't make any difference now." (Lee 124) In 1930's Alabama, it was forbidden for African Americans to enter through the front door of a white person's home. Jim Crow laws reached every aspect of society, and Scout's comment subtly displays this racial discrimination. The smallest routines affected the way African Americans interacted with white people. Sitting in the back of the bus, standing to let a white person sit, and entering through back doors were commonplace rules African Americans had to follow in Southern towns.