TOXIC SOCKS CAUSED ALARM

In the 1860s, suspicions fell on certain dyes, but then evidence pointed elsewhere

Brightly coloured socks are “in.” I’m all for this fashion trend since I’ve always had a soft spot for the chemistry of dyes.

I have no concern about wearing vibrant socks, but that would not have been the case back in the 1860s when multi-coloured socks first appeared on the scene thanks to the new synthetic dyes pioneered by William Henry Perkin’s accidental discovery of mauve. Within a few years of that epic moment in 1856, a whole range of dyes manufactured from coal tar hit the fashion scene. And before long, reports of toxic reactions hit the media.

An 1868 edition of The Lancet, the leading medical journal of the time, featured a report by a physician who had noted that “the dye used in some of the gorgeous socks and other underclothing displayed in the windows of some of the metropolitan hosiers exercises a very deleterious influence upon the skins of the wearers, producing irritation and an eruption upon the skin.” The article also mentions the case of a ballerina performing at the famous Drury Lane Theatre who developed an “anomalous eruption” on one foot and not the other. The mystery was solved by the revelation that the performance required her to wear different coloured socks. It was the foot adorned with a brilliant red sock that was affected! Dr. Webber’s report in The Lancet was picked up by newspapers and the resulting public outcry caused the manufacturer to stop selling the multi-coloured socks and revert to using natural Brazilwood and logwood dyes.

Some of the British socks, though, had been exported to France, where they came to the attention of a Dr. Tardieu. It seems a number of his patients had developed a rash on their feet after wearing the imported socks with red stripes. Tardieu began an investigation into the “poisoned socks” by enlisting the help of Zacharie Roussin, a chemist who extracted the red dye from the socks with alcohol and identified it as “coralline.” This synthetic dye was produced by reacting oxalic acid with phenol, a chemical isolated from coal tar. To investigate its toxicity, Tardieu injected the extracted coralline under the skin of a dog, a rabbit and a frog. All three animals died. He published his findings in the “Gazette des Hopitaux,” causing coralline to quickly fall out of favour with manufacturers, who did not want to be associated with toxic socks.

It wasn’t long before Tardieu’s allegation of the poisonous nature of coralline was challenged. Dr. Landrin, a veterinary surgeon, reported that he had injected dogs and cats with pure coralline without any ill effects, an observation confirmed by a second veterinarian.

How could coralline be poisonous in one case and not in another?

That conundrum was solved by a singular incident, detailed in 1874 in the British Medical Journal. French physician Dr. Bijon suffered from “prickings of the eyelids, with itching and burning sensations” that were exacerbated in a particular room in his house. The room had a different kind of wallpaper from the others, arousing Bijon’s suspicion, since he was aware of accounts that had linked a dye known as “Scheele’s green” with all sorts of health problems. In 1775, Carl Wilhelm Scheele had combined arsenic oxide, sodium carbonate and copper sulphate to produce copper arsenite, a stunning green substance that was widely used to dye fabrics and wallpaper. Arsenic bearing dust from dyed garments and wallpaper tainted rooms, and the situation was further worsened by the moist air in Victorian homes that was conducive to the buildup of mould. Various moulds can feed on Scheele’s green and release volatile and poisonous arsine gas in the process.

Although Bijon did not have green wallpaper, he still wondered about the possible presence of arsenic and had his wallpaper analyzed. Two chemists, using the classic Marsh test, confirmed that arsenic was indeed present, along with coralline, in the wallpaper’s red pattern. But coralline does not contain arsenic! The eventual conclusion was that an arsenic compound had been used as a “mordant.” Deriving from the French verb “to bite,” mordants are inorganic compounds that bind a dye to a fabric. Dr. Tardieu had been unaware of this, and when he injected his animals with the sock extract, he was actually poisoning them with arsenic, not coralline.

There is no question that arsenic poisoning affected many people in the 18th and 19th centuries, but the case that still captivates the public’s imagination the most is one where arsenic poisoning is suspected, but has never been proven. That is the case of Napoleon, who according to some experts died of a stomach bleed, a consequence of stomach cancer caused by arsenic. It is a fact that during his exile on St. Helena, the emperor lived in a room with bright green wallpaper, and that the climate on St. Helena is damp, making mould growth a decided possibility. It is also true that arsenic can cause cancer.

Some of the 14 samples clipped from Napoleon’s hair the day he died did show contamination with arsenic, but since not all of the samples had arsenic, critics of the arsenic poisoning theory suggest that contamination came from later efforts to preserve the samples. Furthermore, Napoleon did not have skin lesions, showed no sign of nerve damage or weight loss, all typical symptoms of arsenic toxicity. In fact, when he died, he was considerably overweight, no longer the “Little Emperor.” Because of his stomach problems, Napoleon also took large doses of calomel, mercurous chloride, which could have caused the stomach bleed that killed him.

Neither Scheele’s green nor arsenic mordants are used these days, and coralline, probably unjustly accused of causing rashes, has also been replaced by a bevy of modern non-irritating synthetics. So there is no need to be concerned of any toxicity when telling an annoying person to put a sock in it.

How could coralline be poisonous in one case and not in another?