Detective Fiction’s Favourite Poisons

Have you ever wondered where the villains in your favourite classic detective fiction found their poisons to commit murder? Author’s descriptions linger on arsenic and cyanide as if they weren’t restricted substances. Well, back then they were not restricted. If you look in a cleaning cupboard from 50 years ago you’d be surprised at the number of toxic chemicals you found under the sink. We would like to think that Grandmother cleaned using bicarbonate of Soda and white vinegar, but that would be incorrect. Not just the bleach we have to lock up today, there was lye used to make soap and is a caustic substance that burns skin and eyes. Trisodium Phosphate was found in most cleaning products and caused breathing problems. In the garden shed, you could find strychnine, cyanide and arsenic to deal with rodents (Miller, 2024). It’s not surprising that people considered murder by poison as the ‘woman’s choice’. So this month, let’s have a look at two of classic detective fiction’s favourite poisons and how they act on the body.

Definitions Time

Classic Detective Fiction or Golden Age of Detective Fiction, is generally considered to be that written in the 1920s or 1930s by authors such as Agatha Christie or Dorothy Sayer.

Agatha Christie is a prime example of Classic Detective fiction.
Credit: Crowell Publishing Company, illustration by Weldon Trench, Public domain, via Wikimedia Commons

The other type of detective fiction from this era is the Hard Boiled Detective.

The Big Sleep portrays the hard-boiled detective.
Credit: Warner Bros., Public domain, via Wikimedia Commons

The Classic Detective is always in control and rarely has flaws, the Hard-boiled Detective is flawed and emotionally involved in solving the crime. Classic fiction is often a closed system, whereas hard-boiled stories tends to be set in a city (Shade, 2024). We might consider Classic Detective Fiction to be ‘cosy’ if it was written about the modern world.

As we’re in definitions, What constitutes a Poison?  RxList defines it as:

“Any substance that can cause severe organ damage or death if ingested, breathed in, injected into the body or absorbed through the skin. Many substances that normally cause no problems, including water and most vitamins, can be poisonous if taken in excessive quantity. Poison treatment depends on the ‘substance.” (Stöppler).

Which is fairly comprehensive.

What poisons were used?

Moving on, without going into the weird and wacky poisons like curare, most of the poisons were readily available. So let’s take a look at arsenic and cyanide.

Arsenic

I’ll start with the old favourite, arsenic.  Before the invention of aniline dyes, Arsenic was the base of choice for bright, green fabric and wallpaper colouring. Even now, museum employees treat Victorian wallpaper sample books with extreme care. Accidental poisoning was rife (Isaac, 2018).  On the other hand, the earliest recorded case of deliberate arsenic poisoning was in AD55, when Emperor Nero murdered his brother Britannicus, to clear his way to the throne. The Borgia family in Italy was noted for arsenic-based murder and Le Poudre du Succession was readily available to help women remove inconvenient husbands at the French Court of Louis XIV (Paul , 2023).

Even so, the metal also has a history of medicinal use in both Western and Chinese medicine for ulcers, abscesses and fevers.  In more recent history, arsenic-based anti-leukaemia drugs are available, and organoarsenical medicines work against multi-drug-resistant bacteria(Paul , 2023).

Despite the good uses, because arsenic was flavourless and odourless, it became the poison of choice for Victorians. The symptoms were often confused with gastrointestinal diseases like cholera, which made it difficult to diagnose (Hughes ,2011).

How does arsenic work?

Most people think of arsenic in terms of symptoms such as nausea, vomiting and diarrhoea(IOWA ).  However, the actual mechanism of toxicity is rarely mentioned.  Arsenic acts on the body in the same way as phosphorus. But, phosphorus is vital for life, arsenic is not.  Adenosine Triphosphate (ATP) is the powerhouse for cells in the body.

The ATP cycle
Credit: Eunice Laurent, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

It provides the energy to drive other biological pathways. Arsenic takes the place of phosphorus in chemical reactions. Without phosphorus, those important pathways no longer function. Lacking medical intervention, arsenic jams up the mechanisms of biology. Thankfully, in World War 1, scientists developed dimercaprol as an antidote to arsenic-based chemical warfare, which is still used today to clear poison from the body (Choi, 2022).

How do we test for Arsenic?

Then

A very early test for arsenic was used as forensic evidence in a trial in the 1700s. The female poisoner was convicted based on evidence of how a white powder looked like arsenic and gave off smoke smelling of garlic when it burned. The smell of garlic was the basis of the test Carl Scheele developed in 1775. More on that here.  But in 1836, English Chemist James Marsh developed a more reliable test for arsenic. He placed a sample of potential poison in a mixture of acid and zinc. Arsenic would precipitate out, leaving a silver sheen on the glassware(Hughes ,2011).

Now

These days, there are quick test kits to test for arsenic in your drinking water. Confirmatory and forensic tests are performed using spectroscopy, either atomic absorption or X-ray fluorescence(Encyclopaedia.com, 2019).

Cyanide

The other favourite poison of classic detective fiction is cyanide, in the form of prussic acid. Where arsenic is a long drawn-out, painful death, cyanide is almost instantaneous. Originally it was used as a rodenticide, so available for nefarious uses in crime fiction. As with arsenic, it is a naturally occurring substance. It tends to  concentrate in seeds and stones of fruits such as apples, almonds and peaches. Again, history lists Emperor Nero as the first user, using it to poison the wells of his enemies.  Later on, the troops of Napoleon III dipped their bayonets in prussic acid during the Franco-Prussian War. As with a lot of poisons, it has medicinal uses: Sodium nitroprusside is an anti-hypertensive drug (Center, 2022).

How does cyanide work?

The interesting thing about both these poisons is that they disrupt the ATP pathway. However, rather than taking the place of phosphorus, Cyanide binds to cytochrome oxidase in the mitochondrial electron transport chain, starving the cells of oxygen.

The Mitochondrial Electron Transport chain.
Credit: Fvasconcellos 22:35, 9 September 2007 (UTC), Public domain, via Wikimedia Commons

Without oxygenative phosphorylation of ATP, the cells rapidly fail (Center, 2022) .

How do we test for cyanide?

Then

In the 1920s, the Prussian Blue Test was used to detect cyanide. Tissue from the autopsy was laid in a solution of 5% caustic potash for 1 minute then moved to a mixture of 2.5% ferrous sulphate and 1% ferric chloride. This was heated to 60°C. After 10 minutes, the autopsy tissue was removed and added to a solution of 1 in 6 hydrochloric acid. After 10 – 15 minutes, the sample would turn blue if cyanide was present (American Experience).

Now

Modern methods of cyanide detection are, thankfully, less labour-intensive. Currently, the test for cyanide in bodily fluids is performed by gas chromatography or by spectrophotometry (Osak, 2021).

Conclusion

The classic detective fiction writers chose their methods for dramatic effect. On one hand, is the long drawn out suffering, and on the other is almost instantaneous oblivion. Thankfully, these deadly chemicals are no longer readily available without a correct license. Other poisons take their place and in turn, they are withdrawn from the shelves when they are found hazardous to human health.  It must not be forgotten that the Golden Age of Detective Fiction brought the use of forensic science to the reading population, and led directly to such television shows as CSI, and all the police dramas. Even the one where the forensic scientist commits the crimes they are investigating. While these shows make life difficult for investigators, detective fiction is important for readers. It allows people a vision of a world where good triumphs over evil, and criminals pay for their crimes. A world of hope.

References

American Experience. Simulating the Prussian Blue Test. The Poisoner’s Handbook. Page 2. https://d43fweuh3sg51.cloudfront.net/media/media_files/amex26_doc_phguide.pdf

Center for Health Security. (2022). Factsheet: Cyanide. The John Hopkins University. https://centerforhealthsecurity.org/sites/default/files/2023-02/cyanide.pdf

Choi, C. (2022). How Does Arsenic Kill? Live Science.22 July. https://www.livescience.com/how-does-arsenic-kill

Encyclopaedia.com (2019). Marsh, James . World of Forensic Science. https://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/marsh-james

Hughes, M. F., Beck, B. D., Chen, Y., Lewis, A. S., & Thomas, D. J. (2011). Arsenic exposure and toxicology: a historical perspective. Toxicological sciences : an official journal of the Society of Toxicology, 123(2), 305–332. https://doi.org/10.1093/toxsci/kfr184

IOWA. Arsenic Poisoning. Health and Human Services. https://hhs.iowa.gov/epi-manual-guide-surveillance-investigation-and-reporting/environmental-disease/arsenic-poisoning#:~:text=Ingesting%20high%20levels%20of%20inorganic,needles”%20in%20hands%20and%20feet

Isaac, S. (2018). Arsenic: a domestic poison. Royal College of Surgeons of England.  12 October. https://www.rcseng.ac.uk/library-and-publications/library/blog/arsenic-a-domestic-poison/#:~:text=In%20the%20Victorian%20era%2C%20arsenic,or%20Brilliant%20Green%20(1814)

Miller, JT. (2024). 9 Highly toxic Old Household Products. This Old House. https://www.thisoldhouse.com/home-safety/21018179/9-highly-toxic-old-household-products

Osak, M., Buszewicz, G., Baj, J., & Teresiński, G. (2021). Determination of Cyanide in Blood for Forensic Toxicology Purposes-A Novel Nci Gc-Ms/Ms Technique. Molecules (Basel, Switzerland), 26(18), 5638. https://doi.org/10.3390/molecules26185638

Paul, N. P., Galván, A. E., Yoshinaga-Sakurai, K., Rosen, B. P., & Yoshinaga, M. (2023). Arsenic in medicine: past, present and future. Biometals: an international journal on the role of metal ions in biology, biochemistry, and medicine, 36(2), 283–301. https://doi.org/10.1007/s10534-022-00371-y

Shade, L. (2024). Hard-boiled vs Classic Detective Fiction. Novel Suspects. https://www.novelsuspects.com/articles/hardboiled-vs-classic-detective-fiction/

Stöppler, MC.  Definition of Poison. RxList. https://www.rxlist.com/poison/definition.htm#:~:text=Poison%3A%20Any%20substance%20that%20can,if%20taken%20in%20excessive%20quantity