There is a firecracker explosion in a classroom. Nobody is hurt, but one student faints.
A main character becomes seriously ill with scarlet fever. That character is seen in bed, looking very sick and near death.
A teenage student places a live snake in her teacher's desk. There is a lot of screaming when the desk is opened.
A little girl is locked in an outhouse by two male classmates when she threatens to tattle on them for something. She is pounding on the door and crying until she is rescued by her teacher.
Reflective of the time period, a schoolteacher raps one of her students on the hand three times when she behaves badly in class. We don't see any wounds - just close-ups of the girl's face, and she is very close to tears. The rapping sound is pretty loud.