Although Murphy's views on race changed over the course of her life, the perspective contained in her book The Black Candle is considered the most consequential because it played a role in creating a widespread "war on drugs mentality" leading to legislation that "defined addiction as a law enforcement problem". A series of articles in Maclean's magazine under her pen name, "Janey Canuck", forms the basis of The Black Candle. Using extensive anecdotes and "expert" opinion, The Black Candle depicts an alarming picture of drug abuse in Canada, detailing Murphy's understanding of the use and effects of opium, cocaine, and pharmaceuticals, as well as a "new menace", "marihuana". Murphy's concern with drugs began when she started coming into "disproportionate contact with Chinese people" in her courtroom because they were over-represented in the Criminal justice system. In addition to professional expertise and her own observations, Murphy was also given a tour of opium dens in Vancouver's Chinatown by local police detectives. Vancouver at the time was in the midst of a moral panic over drugs that was part of the anti-Oriental campaign that precipitated the Chinese Immigration Act of 1923.