The Deadliest Poisons in History (And Why People Stopped Using Them)

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Once people figured out they could kill each other with special substances instead of sharp sticks, the proverbial poison cookie was born. However, there are only so many times you can use the same trick. As people caught on to how poisons worked, and moved them to the forefront of investigations, certain poisons fell out of fashion. We'll take a look at the glory days of them all.

Sometimes when we look around our lives we can't help but think - this situation would be greatly improved with the use of a little poison. After all, can every last one of the Borgias be wrong? Modern day people are not the first to come around to this way of thinking.

Greeks and Romans: Hemlock and Aconite


It's best to start with the classics. When people didn't know where else to turn, they turned to hemlock. It's most famous for being the poison that Socrates drank in the spirit of good citizenship. It would not have been a particularly pleasant death. Accounts of his death say it was peaceful, with feeling going out of his legs first, and the eventual numbness killing him. Actually, hemlock acts as a paralytic that keeps the mind awake. It takes out the muscles and then shuts down the respiratory system, so death comes from waking asphyxiation.

Aconite comes from the plant monkshood. It, reportedly, also has a famous casualty. The emperor Claudius was said to have been poisoned by his wife by aconite in a plate of mushrooms. The wife part of that scenario seems to be an anomaly since aconite was known as "The Mother-In-Law's Poison." It first caused vomiting and diarrhea, and then caused arrhythmic heart function until the person died.


Hemlock and aconite were a great favorite of the Greeks and the Romans. They didn't just poison each other with the direct version of hemlock, but tried to do each other in with the meat of larks, which were said to eat so much hemlock that their flesh was poisonous. Why did they favor these plants so much? Well, it was also given by doctors to ease swelling and calm seizures or muscle spasms. Aconite was a treatment for head colds by doctors - right up until the 20th century. As meticulous as poisoners seem, they often use whatever comes to hand when they need to kill someone. Since they could get hold of both of these poisons and have a seemingly innocent reason for using them, they were ideal. They fell out of favor often because they weren't nearby. Over time, the effects of the poison became known. Occasional throw-back poisoners tried to use them, but as one unlucky Victorian poisoner who had gotten his entire education from a classics textbook found out, medical science moves forward. His "undetectable aconite," was well-known as a poison. Being a poisoner is very much about staying ahead of the curve.

Medieval Peasants: Belladonna and Mandrake

Belladonna gets its name because it's said that peasant women used to rub it in their eyes. It's a paralytic, and would take out the muscles used to constrict their pupils. When they put it on their cheeks it would cause their faces to flush with what looked like blush. They believed that this gave them a dreamy look that was sexy to men. Probably it just tipped the men off that these women knew how to get their hands on some belladonna. Some say that this was the actual poison used on Claudius by his wife. Others say that Macbeth poisoned an entire invading army with it. One of its most famous uses was as a hallucinogenic that witches used on themselves to give them the feeling of flying. When too much was used - and too much can mean a single leaf - people get nauseous, hallucinate, then develop a rapid pulse that trickles down to nothing.


Mandrake poisonings occurred everywhere, but were most common where the European mandrake grew, in Spain and Portugal. This type of mandrake flowers and bears edible fruit. The roots, however, are not to be eaten. Nor do they need to be in order to be poisonous. Today extracts from the root are used to take off warts - with the warning not to expose healthy skin to the compound. Early poisoners didn't issue that warning. Mandrake will take out the liver and kidneys, so wasn't necessarily as fast as others, but it was a great way to dispose of someone without needing to cook for them.


Mandrake and belladonna were, again, commonly used by certain people during a certain time period because they had them close by and no one would blame them for being in possession of them. As the population moved to the city, it became less common to harvest mandrake or inconspicuously maintain a ten foot high belladonna bush. Besides, as industrialization came on, well, there were new opportunities.

(For those of you wondering about digitalis - foxglove - it is surprisingly hard to give someone a lethal dose of it. Modern poisonings are generally only serious when the victim is a young child. It's also time-consuming to distill, which makes a poisoning with it hard to pull off when a family shares a kitchen.)


Ladies and Gentlemen of Industry: Strychnine, Cyanide, and Arsenic

Cyanide is everywhere. It's in the foods we eat. It's in the chemicals around us. Although substances that contained cyanide were used well back in history, it wasn't until 1782, when a Swedish chemist named Scheele distilled hydrogen cyanide, that things really got swinging. It was first used in distinctive blue paints, but once it was discovered that cyanide killed people quickly - and generally painlessly - that it was used by the military to poison people on both sides. Spies famously used cyanide capsules to kill themselves quickly if caught. It brings on unconsciousness first, followed by convulsions, the inability to absorb oxygen, and death. This was the poison that killed (or didn't kill!) Rasputin. Its quickness and effectiveness at first worked it its favor, but soon people caught on. Lizzie Borden might have been convicted if it had been widely known that she had been asking at chemist after chemist for "prussic acid" - another name for hydrogen cyanide - just days before her parents were axed to death. The testimony of the chemists was thrown out of court on a technicality and she was found not guilty. The reason she couldn't get it was, even in an era in which people could buy heroin over-the-counter, it had been involved in too many poisonings. Sadly, it is still used sometimes by the kind of people who don't care if everyone knows their victim has been poisoned.


Strychnine took some time to catch on the west. It was known as a poison (and a possible medicine) in China and India for centuries, but only made its way to Europe in the late 1700s, when people brought over the Strychnos nux-vomica tree. It took even longer for the toxic compound in the seeds to be isolated and distilled. Once it did, it became a poison for birds in the country and rats in the city. That meant had the major quality that every poisoner looks for - it was within reach. This was not a way to poison someone you like. It causes uncontrollable muscle spasms, frothing at the mouth, reflexes that are dramatically greater than the stimuli that produce them, and eventual death from asphyxiation when the muscles are too tensed and erratic to allow for breathing. The first case in England was of a Doctor William Palmer, who killed his gambling associates with strychnine, even though, as a doctor in 1856, he should have been able to get his hands on better stuff. Thomas Neil Cream was next. He was convicted for poisoning a number of prostitutes, and said he had killed more as Jack the Ripper just before he was hanged. Agatha Christie made this poison famous in her first murder mystery, The Mysterious Affair at Styles. Overall, though, it was so quick and so dramatic that it was hard for a murderer to get away with the crime. Now companies that make animal poison often put compounds that dye or flavor food in strychnine so that it can't be consumed.


Arsenic is, in the end, the be-all and end-all of historic poisons. Without a doubt it had the longest run. Technically, it should be back there among the Romans, because it was used even in antiquity. It was called the King of Poisons, and was the favorite of the Borgias. But it wasn't until the Victorian era when it got its queen. Or rather, queens. Though it was said to have Napoleon and a good chunk of the Italian clergy, this eventually became the lady's poison. Women used arsenic, which constricts the veins, to do the opposite of what medieval women did with belladonna. They wanted a white-as-snow, composed face. Girls learned about the properties and dangers of arsenic in school from their friends, and they were very used to carrying it around and dissolving it in liquids to bathe their faces in. It was tasteless, colorless, and odorless. A few grains of the stuff could kill a man. And a few grains did kill many, many men. (Women, to be fair, weren't the only ones to do this. It's been said that an overly harsh arctic exploration leader, Charles Francis Hall, was poisoned by his own men using arsenic.)


The most infamous case of arsenic poisoning came in 1857, and involved one Madeleine Smith. She had taken a lover, who had turned out to be a blackmailing fortune-hunter. When he threatened to go to her father and show him the explicit love-letters that Madeleine had written, Madeleine made nice and invited him to have some cocoa with her on her windowsill after her father was in bed. The lover fell ill, but was good enough to return the next night, when he got the next dose of cocoa. They found over seventy grains of arsenic in his stomach, and a letter from Madeleine asking him to meet her in his pocket. Madeleine was declared innocent - through a wild series of lucky chances for her - but people checked their drinks around her so much that she changed her name and went to America. The Smith trial, and the fact that medical science had advanced to the point where it was possible to count the grains of arsenic in a corpse's stomach, marked the end of a long era. Arsenic was most on-hand in Victorian era, but it had endured because of its invisibility before and after it was used. The effects of arsenic - sweating, confusion, cramping muscles, and stomach pain - could be written off as extreme food poisoning. Not anymore. And because the news of the trial reached across countries and continents, no aspiring poisoner could fail to note how very obvious arsenic poisonings had become. The king was dead.

Belladonna Image: Rillke

Via Mental Floss, UCL, Belladonnakillz, Mason, PLOS, Dartmouth.