The amazing (and deadly) arts and crafts with arsenic
Arsenic, much like lead, is a substance with many useful properties. It provides a brilliant green hue for paint, it kills bacteria as an antibiotic, alloys can be used in semiconductors and batteries, a lovely white glaze can be made for ceramic with it, and it’s a fantastically effective insecticide!
Oh, that last one may have been a hint.
The lovely emerald green color was one of arsenic’s biggest uses well before anyone figured out that it’s also incredibly toxic. Its brightness made it the popular replacement for the previous favorite formulation, Scheele’s Green, which was made with copper.
Scheele’s Green became unpopular as people found it was poisonous but more importantly, tended to darken over time as the copper arsenide oxidized. Therefore, Paris Green came into vogue, which was slightly more stable.
You’ll find Paris Green, or copper(II) acetate triarsenite, in many famous paintings from the 1800s. Georges Seurat’s A Sunday on la Grande Jatte is the prime example of pointillism, and its bright green hues come from arsenic.
It was also used in wallpaper. In the 1892 short story “The Yellow Wallpaper” by Charlotte Gilman, a woman goes gradually insane looking at the yellowish wallpaper of a room in which she is confined. But it’s entirely possible the wallpaper was also literally driving her insane, depending on its formulation!
This is because as the arsenic pigment degrades, it would off-gas. Mold and moisture accelerate the process, which releases arsine gas into the environment. Despite its high lethality, it was never used in World War I as a chemical weapon because it’s also very flammable and would be dangerous to anyone trying to deploy it.
If you can smell the garlic scent of arsine, you’re already enveloped by a more than lethal dose.
But hey, at least the paint has a nice green hue to it.
Somehow, in the mid-1800s, farmers found out that Paris Green paint was also great for killing agricultural pests, including the potato beetle and mice, and went about spraying down crops with it. I don’t think I can even comment on how good an idea that is in retrospect. But it is also the world’s first widely-used insecticide.
(Please, Sherwin-Williams, it’s time to rethink that “COVER THE EARTH” slogan)
But the color! The bright color made it great for clothes too, so factories were dedicated to dyeing fabrics with the nice green tint, with workers dipping their arm into the vat of arsenic-based dye to apply it.
As for its use in medicine, well.. I guess in the era before penicillin, you have to take what you can get. Arsenic defeats bacteria by breaking down their cell membranes. It just has some rather unfortunate side effect on the human as well.
So that’s why we stopped using arsenic to treat bacterial infections. What’s that? We might have to start using it again? Antibiotic resistance is getting too strong for current antibiotics so we’re considering doping them with arsenic to increase potency?
We’re in for a fun future.