Of Cerberus, Cleopatra, and Murder

by Deborah Blum

The poison, according to Greek mythology, could be found at the gates of hell. It dripped from the jaws of Cerberus, the hulking three-headed dog that guarded the entrance to the underworld. And when the dog drooled on the ground, strangely beautiful flowers sprang up, each one poisonous at its heart.

The poison always carried the taint of dark magic. People called it wolfsbane, dogsbane, even -- rather horrifyingly -- wifesbane. Its reputation called to writers over the years. Oscar Wilde used it in his story of a determined murderer, Lord Arthur Savile's Crime. It was used by a character in James Joyce's Ulysses who commits suicide. And author J.K. Rowling wrote it into her wildly successful Harry Potter series, where potions master Severus Snape brewed it into a drink that rendered werewolves harmless.

Today, we tend to refer to this poison rather prosaically as aconite. I love the notion of it being drooled by hellish dogs but, in fact, it's simply part of the internal chemistry of a rather decorative plant popularly called monkshood, with the Latin name of Aconitum napellus.

In an academic sense, people have long been fascinated by aconite's lethal qualities, believing that a compound this powerful must surely have the ability to alter history. Just last month, researchers proposed that the suicidal death of the ancient Egyptian queen, Cleopatra, might not have been due to snakebite, as suggested by legend (and William Shakespeare). Rather, a German historian proposed that the queen's purported symptoms fit better with a poison cocktail, containing ingredients such as hemlock and aconite.

But in a less academic sense, as a murder trial in London earlier this year reminds us, the poison also remains as a murderer's weapon. The pure alkaloid (called aconitine) is so deadly that it's considered fatal to humans at as little as 5 milligrams (about .0002 ounces.) Fortunately, aconitine is somewhat dilute in the plant material itself -- which maybe one reason why, in this year's rare use of aconite, one of the victims survived.

The story of this winter's murder in London began with a 39-year-old man named Lakhvinder Cheema, who decided to give up a long-time relationship with a married mistress and tie the knot himself. His chosen bride was a 21-year-old recent immigrant to the United Kingdom. She was also 24 years younger than the man's ex-lover.

According to the prosecution, the rejected mistress, Lakvir Singh, responded by collecting seeds from an aconite plant. These contain aconitine, but not at the concentration found in the plant's turnip-shaped roots. Singh then let herself into her ex-lover's apartment, using her key, and mixed the seeds into a container of left-over curry in his refrigerator. That evening Cheema and his fiance had the curry for dinner.

Chemically, aconitine resembles a tangled chain of carbon, hydrogen, and oxygen atoms along with one atom of nitrogen. Its ornate structure allows it to rather efficiently unlock and poison certain nerve cells. In particular, it opens and poisons calcium channels leading to the heart, disrupting the nervous system messages that keep it beating. People exposed to the poison complain of numbness and tingling as their nerves cells fray. Death can occur in less than ten minutes. Cheema called for ambulance as he became increasingly ill. He died with the hour. Doctors at the hospital put his girlfriend into a coma while they identified the poison and treated her. She'd eaten far less of the curry, and she survived.

Singh was convicted of murder on February 9 and sentenced to life in prison. Prosecutors noted that it was the first known aconite murder in England in more than 125 years. In a widely publicized 1882 trial, British doctor George Henry Lamson was convicted of killing his 18-year-old brother-in-law by feeding him a cake poisoned with aconitine. Lamson had wanted his wife to inherit all of a family estate rather than sharing it with a teenage boy.

The lawyers at the recent trial expressed astonishment that such an old-fashioned poison would reappear in modern England. But although the names of poisons may change over the years, their lethal qualities do not abate. And the motives of killers -- jealousy, rage, greed?

Those have stayed the same since Cerberus was drooling poison for the use of the ancient gods.