The dark history of arsenic - Neil Bradbury

It was 120 BCE, and Mithridates’ father, the ruler of Pontus,

had been poisoned by enemies.

Fearing that his mother might poison him to usurp the throne,

Mithridates went into hiding.

When he reappeared, he committed himself to building his tolerance to poison,

allegedly micro-dosing various toxins each day.

He reached his 70s, and chose to die by sword,

evading capture.

No substance has perhaps been as constant an ally to insidious scheming as arsenic,

the so-called “king of poisons.”

It’s a naturally occurring, widely distributed metallic element.

In its chemically pure form,

it isn’t much of a threat because our bodies don’t absorb it well;

it’s when arsenic combines with other elements that things get dangerous.

When arsenic reacts with oxygen,

it may assume its most common poisonous form:

white arsenic, a powder that can be immediately lethal or kill over time.

At the molecular level, white arsenic resembles phosphate,

which is essential to the body's basic cellular reactions.

When white arsenic enters the body, it replaces phosphates,

compromising critical processes like cellular energy production.

The symptoms of arsenic poisoning overlap with common illnesses in history.

And white arsenic is inconspicuously odorless and tasteless.

These characteristics made it a choice murder weapon.

In ancient Egypt and Greece,

people encountered arsenic while mining and smelting metals,

and came to recognize its powers.

The first preparation of white arsenic on record

is attributed to Islamic Golden Age alchemist Jabir ibn Hayyan,

around the 8th century.

Poisoning became prevalent in Renaissance Italy,

where elites like the Venetian Council of Ten decided who to assassinate

and enlisted alchemists, pharmacists, and doctors

to prepare the appropriate poison.

The House of Borgia mastered the murderous art,

reportedly wielding an arsenic-laced powder called Cantarella

that they’d sprinkle into special guests’ goblets.

And during French King Louis XIV's reign,

arsenic ran rampant among Parisian high society,

earning it the moniker of “inheritance powder.”

In 1675, the five-year Affair of the Poisons kicked off

with a noblewoman confessing to murdering her father and brothers—

and revealing that Paris harbored an extensive underground network

of poison peddling.

One of its central figures was Catherine Monvoisin.

In addition to performing divinations and black masses,

she formulated so-called love potions as well as more ghastly concoctions

containing aconite, belladonna, and arsenic.

One of her clients was a member of the royal court

whose husband died under mysterious circumstances;

another was the king’s very own mistress.

Arsenic became a more widespread weapon during the Industrial Revolution.

Demand for metals, like iron, skyrocketed.

And as people melted impure ores in furnaces,

some byproducts became airborne and accumulated on chimneys—

including white arsenic.

The powder was scraped off in abundance and sold cheap to city-dwellers,

who channeled its powers against pests— and sometimes, people.

Arsenic also found its way into ubiquitous goods.

In 1775, Swedish chemist Carl Wilhelm Scheele

created a copper-arsenic mixture that yielded a brilliant green hue.

Scheele’s green soon pigmented paint, textiles, toys, soaps, cosmetics,

and food coloring.

By the late 1800s, 80% of English wallpaper contained arsenic.

But its lethality loomed.

Several children were said to have died from inadvertently ingesting arsenic,

and a public campaign finally had it banned from households.

Meanwhile, deliberate arsenic poisoning persisted.

And because forensic arsenic tests remained rudimentary,

people kept getting away with it.

In 1832, chemist James Marsh consulted on a homicide case

where a man was accused of arsenic-lacing his grandfather’s coffee.

Marsh ran the standard test, which yielded a yellowy deposit,

confirming the sample was positive for arsenic.

But the result was chemically unstable.

And by the time Marsh presented it in court,

the color had deteriorated, and the jury acquitted the accused.

So, Marsh created a new test,

whereby an arsenic-containing sample would react with zinc and acid

to produce arsine gas.

Once ignited, it would reveal a solid arsenic deposit.

It was the first truly reliable arsenic test.

Newer tests later took its place and antidotes became available,

but history remains laced with arsenic’s perverse power—

sprinkled with scandal and dashed with deceit.