Essence of Insanity. Sarah had never heared of that before. She took out her notes and ruled off after the section on Plimpies. and titles the page: Essence of Insanity. Now what woulkd it contain. Sarah raised her hand "Screaming kids? - just kidding. Maybe that thing that contained acids that mess up your mind? An essence was usually for medicinial purposes was it not?" said she.