The Victorians' favourite green was made with arsenic.
Scheele's green, invented in 1775, coloured 19th-century wallpaper, dresses, candles, toys and even sweets. It was a copper arsenite. Journals reported children wasting away in green rooms, and a young woman who dusted fake leaves with it died with her fingernails stained green.
The Swedish chemist Carl Wilhelm Scheele invented the pigment in 1775 and published the recipe in 1778. Made by combining a sodium arsenite solution with copper sulfate, it produced a bright yellowish green that outshone the older copper carbonate greens. Through the early and middle 19th century it was everywhere: paints, wallpapers, fabrics, book covers, paper linings, wax candles and children's toys.
Its toxicity was not widely understood at first. Reports described ladies in green dresses fainting, printers overcome by fumes and children poisoned when dyed candles were burned at a Christmas party. It was even used to colour sweets such as green blancmange, which is said to have left a long-standing Scottish suspicion of green confectionery. In 1861, 19-year-old Matilda Scheueur died after repeated arsenic poisoning from her job dusting artificial foliage with the pigment; the publicity helped turn opinion against it.
How did wallpaper harm people? One idea is that flakes of pigment became airborne dust. Another is that damp, mouldy walls released arsenic-containing gas, since certain moulds convert arsenic pigments into volatile compounds. The Italian physician Bartolomeo Gosio described such 'Gosio gas' in 1893, but newer studies suggest that particular gas is only weakly toxic, so the mechanism is still debated.
A popular story says Napoleon was killed by the green wallpaper of his damp house on St Helena, and arsenic was indeed found in his hair. But the cause of his death is generally accepted to have been stomach cancer. Scheele's green went out of fashion from the 1860s, the last wallpaper brand using it stopped by the 1890s, and it lingered only as an insecticide into the 1930s.
Source: Wikipedia — Scheele's green · Text summarised from Wikipedia (CC BY-SA 4.0)
