Laughing Gas is the title of several American short films (1907, 1914 starring Charlie Chaplin, 1915, 1920) whose plot revolves around real or would-be dentists.

Plot

The plot is that of a black woman going to the dentist for a toothache and being given laughing gas. On her way walking home, and in other situations, she can't stop laughing, and everyone she meets "catches" the laughter from her, including a vendor and police officers.