A crucible is a container used in laboratory processes where its contents can be heated to very high temperatures and chemical reactions can occur. It is a metaphor of the town of Salem. Initiating the reaction, the girls began accusing others of possessing them and tempting them to sing and dance in commune with the devil and their dead sisters. To protect themselves from being whipped, Abigail and her followers continue to accuse more of witchcraft. Like a crucible is an apt container for heating chemicals, the strict religious doctrine of Salem provides kindling for the fire that is to erupt as hysteria, fear and mindless prosecution. The accusations seem to increase exponentially just as heated chemicals will ‘mindlessly’ quicken their movement and react violently. The play is also an allegory of the growing fear of communism during the 1940s and 1950s. That is often referred to as a witch hunt led by, then, Senator Joseph McCarthy.