In Germany, in 1814, Wilhelm Sattler created an extremely toxic arsenic and verdigris compound pigment, Schweinfurt green-known also as Paris, Vienna, or emerald green-which became an instant favorite amongst designers and manufacturers the world over, thanks to its versatility in creating enduring yellows, vivid greens, and brilliant blues. Most insidiously, the arsenic-laced pigment made its way into intricately patterned, brightly colored wallpapers and from there, as they became increasingly in vogue, into the Victorian home. As its use became widespread, commercial arsenic mines...