Hitchcock’s Psycho was the first American film to ever show a toilet flushing on screen.
I love discovering that a personal horror-film favourite is based on a novel:
“Psycho was the first movie adapted from a novel by Robert Bloch (1917-1994), and despite its great success, he only received $9,000 from selling the film rights to his novel. However, the movie helped his career tremendously, and he wrote for a number of films and television shows over the next three decades, most of them in the horror/thriller/suspense genre, such as The Night Walker (1964) starring Barbara Stanwyck, and Strait-Jacket (1964) with Joan Crawford.” (from Trivia & Fun Facts About PSYCHO by Turner Classic Movies)
Adding Bloch to my reading list!