First, Reverend Parris says that he discovered his daughter, Betty, and his niece, Abigail, "dancing like heathen" in the woods. He also says that he saw Tituba "waving her arms over the fire" when he burst in upon them, and he describes her as chanting in gibberish and "swaying like a dumb beast" over the fire. He also says that he saw a dress lying in the grass and that he thinks he saw one of the girls "naked running through the trees."
Later, when the Putnams arrive, Goody Putnam confesses to sending her one surviving child, Ruth, to Parris's slave, Tituba, to ask her to conjure the spirits of her dead children in order to find out who killed them. It seems, then, that he saw part of this ritual. Further, when Betty momentarily wakes up (when all the adults are out of the room), she accuses Abigail of drinking "a charm" to murder Goody Proctor, the wife of the man with whom Abigail had an affair. When Mr. Hale arrives, he questions Parris, and Parris says that he also saw a kettle on the fire where the girls were dancing and that "there were some movement" in the liquid there.