Nowadays, we tend to give arsenic a pretty wide berth — the element isn’t known as the “king of poisons” for nothing. Its toxicity stems from its similarity to the life-sustaining nutrient phosphorus, which allows arsenic to invade important chemical reactions in the body and disrupt them. The element is also happy to mix with other ones, often forming deadly and undetectable powders with no taste or smell.
Yet this versatility is what made arsenic so ubiquitous in a variety of Victorian-era products, from home decor and wallpaper to clothing and books. When combined with copper oxide and lime, it produced an eye-catching compound called copper acetoarsenite, or emerald green.
