Methods of Murder - Agatha Christie

It has been suggested the novels of Agatha Christie were first inspired by the method of murder and the setting up of the actual deed, then plotting back through the novel from this, all before she started writing.

One of Christie’s favourite methods of murder was by poisoning.

In World War One she worked as both a nurse and later a pharmacy dispenser. It was during this time that the developed a fascination with poisons and their effects. Poisons like strychnine and arsenic were obvious ones to choose at this time, as they could both be purchased easily by a villain in the form of rat poison, fly paper and other common, over the counter items used to eradicate vermin. She had the knowledge, however, to add bromine to a medicine containing a small dose of strychnine, which then formed a precipitation at the bottom of the bottle, rendering the final dose lethal. This method killed off Emily Inglethorp in The Mysterious Affair at Styles.

The tell-tale symptoms of thallium were given in such detail in The Pale Horse that readers went on to recognise thallium poisoning in real life and save lives. She also knew that other medications such as digitalis can be used to relieve some heart conditions, but used in excess they will cause a permanent cessation of the heartbeat.

Cyanide, however, was the poison she used most often, followed in popularity by strychnine, digitalis then morphine. High concentrations of cyanide can lead to death in minutes, or it can be used over a longer period to debilitation and eventual death. She used cyanide in And Then There Were None, A Pocketful of Rye, The Mirror Crack’d from Side to Side, and it even featured in the title of Sparkling

Cyanide.