“A great deal of slow poisoning is going on in Great Britain,” wrote Birmingham doctor William Hinds in 1857. He was among a growing movement of people concerned about a toxic killer in their daily lives: namely, their wallpaper.

Lucinda Hawksley’s Bitten by Witch Fever: Wallpaper & Arsenic in the Nineteenth-Century Home, out this month from Thames & Hudson, chronicles the rise of poisonous pigments in the 19th century through the burgeoning British wallpaper trade. The beautifully designed book includes facsimiles of 275 Victorian wallpapers, all of which were found to contain arsenic after recent testing by the British National Archives.

The title is taken from a dismissive quote by the most famous wallpaper designer to come out of that time: William Morris. The “doctors were bitten as people were bitten by the witch fever,” he wrote to his friend Thomas Wardle in 1885. In other words, it was all hysteria.

Morris didn’t just have his identity as an artist linked to the wallpaper industry and its arsenic pigments, which allowed for the mass production of newly vibrant and durable colors; his wealth also came from his family’s mine, Devon Great Consols, which was among the leading producers of arsenic. Part of Hawksley’s research was to delve into how Morris — a philanthropist who advocated for humane working conditions in his decorative arts company — overlooked the incredible hazards of the arsenic mine and the use of poison in his wallpaper.

“One of the great unanswered questions about Morris is why he never visited the mines or concerned himself with the welfare of the miners and their families,” Hawksley writes. Perhaps, like much of the country, he was unable to resist the huge profits of the industry.

Back in 1771, Swedish chemist Carl Wilhelm Scheele had developed a green pigment from a compound of copper arsenite. In 1814, Wilhelm Sattler, a German industrialist, seemingly perfected it by using arsenic and verdigris for a more steadfast green. The pigment could also be mixed to create bright yellows and rich blues, perfect for the Victorian craze for opulent interior design. In 1834, Britain produced 1,222,753 rolls of wallpaper; that number rose by 2,615% to 32,000,000 rolls in 1874.

That arsenic was poisonous was certainly not a secret; every Victorian home had a bit of the powder lying around for rats and mice, and people likely knew tales of the “inheritance powder” being used for murder. Yet they also applied arsenic cosmetics, gave their children toys painted with arsenic, wore dresses and hats dyed with arsenic, and ate meat dipped into it to keep away flies. Alison Matthews David, in her 2015 book Fashion Victims, notes that as nature was vanishing from the industrial city, the “Emerald Green” became popular on artificial flowers worn in the hair. She points out that just as Baudelaire was titling his book of dark poems Les Fleurs du Mal (The Flowers of Evil), the death of a young Parisian artificial florist was being investigated in regards to the poisonous colors.

In some kind of disconnect, people believed that only by licking the walls would they get poisoned, or only by the green colors. In this way, it wasn’t too different from the radium cosmetics that took off in the mid-20th century, even while the potentially dangerous power of radiation was evident. Left untouched, Victorian wallpaper could still release flakes of arsenic into the air or produce arsenical gas when conditions were damp.

Hawksley adds that while other European countries regulated arsenic, Britain was slow, and it was only public demand and new dye techniques that changed the industry. Initial reports of wallpaper poisoning were shared in medical literature in the late 1850s, and in an especially horrifying incident in 1862, children died in an east London home after they’d torn down the wallpaper and licked the green off its surface. Queen Victoria reportedly had all the green wallpaper torn down in Buckingham Palace after a visiting dignitary became ill in 1879. Yet it wasn’t until the Factory Workshop Acts of 1883 and 1895 that Parliament instituted any sort of regulations for conditions in factories where workers regularly encountered arsenic.

“It proved effective: arsenic was responsible for a mere 1 per cent of the cases involving industrial poisoning by the twentieth century,” Hawksley writes of the new guidelines. By then, a consumer interest in “arsenic free” wallpaper had changed the market. “In the absence of government intervention, the people of Britain had used the power of their pocketbooks to make the presence of arsenic in wallpapers obsolete,” she concludes, “and as a result, their homes no longer held a fatal secret.”

Lucinda Hawksley’s Bitten by Witch Fever: Wallpaper & Arsenic in the Nineteenth-Century Home is out now from Thames & Hudson.