The colour of death – Scheele’s green

Scheele’s Green is the colour named after the Swedish chemist Carl Wilhelm Scheele, who accidentally discovered it during one of his experiments. The new colour was happily welcomed and embraced in various applications. It was used for dyeing fabrics, wallpapers, and window blinds, but it was also used as an insecticide, fungicide, and rodenticide. This yellowish-green shade gained great popularity in the Victorian era. However, behind its elegance, Scheele’s Green hides a deadly secret.

A deadly combination

During his career, Swedish chemist Carl Wilhelm Scheele laid the foundations of modern chemistry, including discovering oxygen as a chemical element. Despite numerous achievements, one of his findings had a harmful outcome – the discovery of Scheele’s Green, whose main components form the toxic combination of copper arsenite.

The dark side of beauty

The death of a 19-year-old, Matilda Scheurer, a London artificial flower maker, is evidence of the colour’s deadly nature. Her task was to sprinkle faux leaves using this colour, which is how she inhaled the poison. Matilda’s sclera and nails turned green, she vomited and saw green. Moreover, the autopsy later confirmed that her stomach, liver, and lungs were contaminated with an exceptional amount of arsenic. Scheele’s Green could also enter the human body through various clothing items and the extremely popular green wallpapers. One of many theories speculating about Napoleon’s death blames his green wallpaper for poisoning him with arsenic. Extreme amounts of arsenic were also found in Napoleon’s hair. Moreover, X-ray fluorescence measurements of wallpaper samples from his room have supported these claims.  Arsine is a highly toxic gas that can be released from these wallpapers because of some mould species that develop on them.

Toxicity of Scheele’s colour

The consequences of acute arsenic exposure are numerous, from gastrointestinal to neurological issues. They often include gastroenteritis, hypotension, coughing, dyspnoea, proteinuria, haematuria, acute renal failure, and headaches. Subacute exposure (1-3 weeks) results in reversible sensorimotor polyneuropathy accompanied by various haematological abnormalities, including thrombocytopenia, leukopenia, and anaemia. On the other hand, chronic exposure leads to hyperpigmentation. Arsenic is also linked to basal cell carcinoma, angiosarcoma, hepatomegaly, ascites, as well as lung and bladder cancer.

Decline in popularity and replacement

At the time when the authorities began to regulate arsenic, green wallpapers had already gone out of fashion. Scheele’s Green was eventually replaced with a safer alternative – the cobalt green. However, the tragic shade of Scheele’s Green remains an important historical lesson about responsibility in the scientific world, while it also exposes the devastating human urge to blindly follow trends and aesthetics, despite being aware of the risks they may potentially pose.

Translated by: Dea Radek