The film was not screened at many local cinemas, due to the tone of the film, and out of respect for the surviving victims, and the relatives of the dead.
The "Newton's Diamond" that Graham is obsessed with is a fictional device. Antimony sulfide forms a crystal called stibnite which is gray and opaque, not clear and colorless like most gem-quality diamonds. "Diamond" was the name of Isaac Newton's dog.
The story is based on the story of Graham Young, known locally as The Bovingdon Poisoner.
In this film, Arthur Cox plays Ray, one of Graham Young's colleagues at the factory job he obtains upon his release from prison. Two years earlier, Cox played Bob Egle, Ray's real-life counterpart, in an episode of the docudrama series Crime Story (1992) - Terrible Coldness: Graham Young (1993).
At around 6 1/2 minutes, there is a close up of Graham's desk, and a monograph called "Mercury Arcs" can clearly be seen. This was based on a lecture course given at Liverpool University, and first published in 1936.
The monograph covers the design, function and application of mercury-arc rectifiers, which were the only practical way to produce rectified DC from mains AC at the time.
By an odd coincidence, the Hirst Research Centre, used as a background throughout, was heavily involved in power semiconductor research after the war - which rendered mercury arc rectification obsolete.
The monograph covers the design, function and application of mercury-arc rectifiers, which were the only practical way to produce rectified DC from mains AC at the time.
By an odd coincidence, the Hirst Research Centre, used as a background throughout, was heavily involved in power semiconductor research after the war - which rendered mercury arc rectification obsolete.