Why is the play titled the crucible? short essay using quotes

A crucible is a bowl in which substances are ground and then purified.  As the term is used in the title of this play, "crucible" represents both a test and a purification process.  The major characters are placed in situations that try their characters.  According to the laws at that time, anyone accused of witchcraft was brought before the courts to testify. Answering "no" to a charge of witchcraft could result in death.

Quotes: “I speak my own sins; I cannot judge another. I have no tongue for it.”

“It is rare for people to be asked the question which puts them squarely in front of themselves” "We are what we always were in Salem, but now the little crazy children are jangling the keys of the kingdom, and common vengeance writes the law!”

the answer is b. the tracer looks harmless in flight, but the pilot’s bitten lips and white knuckles suggest how dangerous it can be.

ugly things like bugs or something?