01:00 AM EST on Monday, December 19, 2005

WHAT COULD POSSIBLY be more innocent, more unthreatening in its mission, than wallpaper? It adheres unobtrusively to the walls while silently providing a dash of color to an otherwise banal vertical surface. It imparts, at best, a cheerful touch to the room, and at worst, an unaesthetic clash of hues.

The 19th Century witnessed an increasing use of decorative wallpaper, particularly in the more elegant homes of early-Victorian England. Many of these papers were hand-printed, with hand-carved blocks, and had brilliant hues.

Before aniline dyes had been synthesized by the English chemist William Perkin, in the late 1850s, wallpaper color depended on mineral-based pigments: compounds of chromium, mercury, cadmium, lead, antimony and, pre-eminently, arsenic. (A visit to any store offering oil pigments for the contemporary artist's palette will verify that these pigments -- such as lead chromate, lead white, Prussian blue, cadmium yellow and emerald green -- are still used by serious portrait artists.) By 1870, England was annually manufacturing over 30 million rolls of wallpaper.

The wallpapers of the early-Victorian years were resplendent in their vividness. One color, a copper arsenite called Scheele Green (named for its discoverer, the Swedish chemist Karl Scheele [1742-86]) was particularly sought after because of its florid intensity. Many an elegant lady's dress was also dyed with this coloring agent. Gilbert and Sullivan, in one of their 1869 songs, offered this grim rhyme: "No airy fairy she, / As she hangs in arsenic green, / From a highly impossible tree, / In a highly impossible scene."

The wallpaper industry in England during the 19th Century was dominated by a company owned by the poet, artist, leader of the Arts and Crafts revival, socialist and consummate aesthete William Morris (1834-96). Morris was one of England's greatest poets but nonetheless concentrated much of his energies in architecture and later in the design and manufacture of fabrics, tapestries and wallpapers. By 1880, his wallpaper company dominated the decorating industry.

It was not long before something was amiss in those bedrooms wallpapered with products from the Morris factories -- particularly papers printed with Scheele Green. Children sleeping in such bedrooms often developed a curious sequence of symptoms, beginning with running, reddened eyes, painful mouth and a diffuse, reddish skin rash. Some of these middle-class children went on to weight loss, chronic diarrhea and death. One recollection might have served as a warning: Bedrooms papered with green dyes tended to have fewer, if any, bed bugs -- comparable perhaps to the early warnings rendered by canaries in coal mines.

The British medical journal The Lancet recognized these symptoms as those of accumulative arsenic poisoning. The journal then campaigned to ban wallpaper containing arsenic. The London Times declared: "It was not very uncommon for children who slept in a bedroom thus papered even to die of arsenical poisoning." The association between green-tinted wallpaper and subsequent arsenical intoxication was indisputable, but the physiologic mechanism by which the green dye in the wallpaper poisoned the children remained in dispute, as did why children more than adults were affected. These dyes were also used in such products as artifical flowers, toys and birthday-cake decorations.

The problem was not clarified until 1890, when the scientist Bartolomeo Gosio (1865-1944) began his study of the unexplained deaths of over 1,000 Italian children. He first noted that all of these children had slept in rooms with wallpaper dyed with either Scheele Green or Paris Green (another copper-arsenite dye); and that when the wallpaper became damp, in humid weather, the accumulated mildew converted the copper arsenite into a lethal gas, called trimethylarsine, which settled to the floor of the room -- typically where the children played.

Gosio demonstrated that certain species of mold and bacteria, proliferating in mildew, converted the arsenic into a heavy gas. A square meter of green-dyed wallpaper contained, on average, 700 milligrams of arsenic; an average bedroom, therefore, might store over 30,000 milligrams of arsenic -- enough to kill about 100 people. This conjunction of green wallpaper and sickening children came to be known as Gosio's disease.

And William Morris? To his dying day, he declared his wallpapers to be innocent of any harmful ingredients. Long after his competitors advertised their wallpaper products as "totally free of arsenic," the artful Morris papers continued to use Scheele Green dye. Morris's father was part owner of the Devonshire Mining Company, one of the great sources of copper in England. The discarded waste products in the refining of copper were belatedly shown to be rich in arsenic, and so the company also became England's largest producer of arsenic, used as an insecticide and in glass manufacturing.

Morris, friend of Rossetti and Swinburne, leader of the early socialist movement in England, environmentalist, and owner of factories employing child labor, was described by Professor Andy Meharg, of Aberdeen University, thus: "Morris was a hypocrite, not the normal Victorian who was pleased with God's financial blessing from child labour and terrible working conditions but who also was the pre-eminent British communist. He not once confesses to any remorse regarding his dealings with the toxic wallpaper industry or the gains gotten from arsenic mining."

Lethal wallpaper is now a tragedy of the past.

A whiff of the arsenical gases also lingers around the death of Napoleon. After his defeat at Waterloo, in 1815, he was exiled to Longwood House, on the remote island of St. Helena, until his death, at age 52, in 1821. Death was said to have been caused by gastric cancer, but was never verified.

Napoleon's bedroom was artfully papered with English wallpaper, which when analyzed in 1992, by the BBC, was shown to be laden with arsenic. And his hair, when analyzed in 1995 by the FBI laboratories, contained excessive amounts of arsenic.

Some historians, however, attribute Napoleon's death to intentional arsenic poisoning, rendered by Count Montholon, head of Longwood House -- in revenge for the child that Napoleon had sired with Montholon's wife.

Stanley M. Aronson, M.D., a weekly contributor, is dean of medicine emeritus at Brown University.