How Agatha Christie Revolutionised The Use of Poison in Crime Stories

Published in 1920, The Mysterious Affair at Styles is Agatha Christie’s first novel that came from a dare from her sister Madge who challenged her to write a story.

The story begins when Hastings is sent back to England from the First World War because of an injury.

He is then invited to stay with his old friend John Cavendish and his family.

Everything is fine until John’s stepmother, Mrs. Inglethorp, dies from poisoning.

Hercule Poirot, another old friend of Hastings, then comes to investigate this case.

Poison in Agatha Christie’s Works

“Christie seemed to have a major fascination with using poison as a way for murder. In fact, over 30 characters met their death with a poison in her works.”

During Christie’s time, and specifically during the time of this novel, poison was easy to find in British homes.

People would have them in their bathroom cabinets, their kitchens, and even their gardens. Pharmacies would sell poison as medicine, and doctors would prescribe and give it to their patients.

“Soon, anyone and everyone could afford enough arsenic to dispatch an unwanted relative or inconvenient enemy.” Kathryn Harkup

Having to study medicine to be accepted as a volunteer nurse in World War I and World War II, Christie’s knowledge of poisons came from direct experience and a lifetime interest in the subject, which kept her up to date with new developments in drugs and pharmaceutical practice.

The Mysterious Affair at Styles was reviewed, at the time of its publication, in the Pharmaceutical Journal, and was described as having the “rare merit of being correctly written”.

This is an accomplishment that not all crime novel writers can declare of themselves, since Christie is one of the few whose work is scientifically correct and detail-oriented, specifically in terms of how poisons work and their effects.

In this novel, the reader learns a lot about strychnine, its effects, and its dangers through Poirot’s investigation.

“Well, strychnine is a fairly rapid poison. Its effects would be felt very soon, probably in about an hour. Yet, in Mrs. Inglethorp’s case, the symptoms do not manifest themselves until five o’clock the next morning: nine hours! But a heavy meal, taken at about the same time as the poison, might retard its effects, though hardly to that extent.” (Page 60)

The Mysterious Affair at Styles, like all of Christie’s novels, is part of the “Golden Age of Detective Fiction”, and, considering Harkup’s research, it seems equally to have been the golden age of poisons, after the first flowering of organic chemistry and before the stricter regulations that arrived after the Second World War.

The fact that anyone can have access to the weapon that the killer used in this novel, immolates the war mentality of the time.

During this time, people in Britain were feeling paranoia and suspicion towards anyone who came from the outside, with the fear of the German spies. Thus, this novel makes detectives and suspects out of everyone.

“He was already under suspicion, and by making the matter public I secured the services of about ten amateur detectives, who would be watching him unceasingly” (page 289).

The Choice of Strychnine in This Novel Was Unusual for Its time

The reason this novel was popular at the time, was mostly because of how different it was for readers to read about a murder weapon that was not commonly present in detective fiction before.

Many other poisons were being used in crime novels as murder weapons. However, to present the murder weapon as a poison common in people’s homes, Christie alerts the readers for its danger of fatality and adds to the paranoia felt at the time.

“If you people only knew how fatally easy it is to poison someone by mistake, you wouldn’t joke about it.” (Page 32)

The choice of strychnine as the poison used in this murder could be a reference to an actual murder. It is uncertain, but the Anglo-Indian author Ruskin Bond has discussed the possibility of this story being based on an actual murder that happened in India.

Either way, the use of this poison for murder was something unusual with only two other novels before this one using it: Alexandre Dumas’ The Count of Monte Cristo (1844) and Arthur Conan Doyle’s The Sign of Four (1890).

A reason for Christie’s choice of poison could be because of it being easily absorbed, and since it has a rapid onset of action, its effects are impressively dramatic.

Affecting the Central Nervous System (CNS) drastically and causing heavy muscle spams, this poison is the perfect murder weapon for a writer to add to his story since it will bring extra dramatic impact to the murder and since it is something that was common for people to have in their house, adds more mystery and brings the possibility of everyone being a suspect.

In addition, death from Strychnine occurs two to three hours after exposure. This gives the murderer enough time to strategize and create an alibi.

Poison as a Plot Device

Overall, poison, and the death that it causes in Christie’s novels, specifically in The Mysterious Affair at Styles, functions as a plot device.

Without the crime, there would be no crime novel.

The resolution of the crime and the understanding of the whole process of the poison, — how it can be consumed, how long it takes to have an effect, how much is a lethal dosage, and the body’s reaction, — gives layers to the story that other weapons don’t.

From the beginning of the story until the end, there is a build-up focused on the murder. Being the poison the murder weapon, the plot also revolves around it.

Poison works as a plot device in this novel since Christie is adding it not only as a weapon used to murder Mrs. Inglethorp, but also to develop connections between the other characters. She does this by having characters seem or act suspiciously when someone refers to the poison.

In addition, by adding a doctor to the group of people close to the victim, Christie adds an even easier way for the poison to be in the property and adds the idea that anyone could have taken it from him.

Final Thoughts

“Give me a decent bottle of poison, and I’ll construct the perfect crime.” — Agatha Christie

Agatha Christie is known for her fantastic plots and well-developed characters, but her knowledge of chemistry and how she wrote such realistic descriptions of the toxin’s symptoms in her novels, is why she has been crowned “The Queen of Crime”. It is because of her writing brilliance and careful attention to detail that her novels live on.

Christie’s knowledge about poison and toxic substances helped her to create all these different ways to murder someone in a quiet and discreet way.

When talking about poison in Agatha Christie’s novels, it is necessary to take into consideration the time of these novels, and how poison was present in British society.

Poison is something that is easy to hide, and it was easy to pass as an accident that the victim did to themselves. Since poisons were being taken as medicine, it was easy for people to overdose on them.

Overall, Christie’s use of poison in her novels, and specifically in The Mysterious Affair at Styles, is a product of its time and revolutionized the use of poisons in crime stories.

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