Regina's Rants

Colours have different origins, compositions, and meanings. Some pigments’ names evoke distant and exotic lands, brought to the west by merchants’ caravans or ships that have crossed seas teeming with, what they thought back then, monsters.  While some pigments used by painters and manufacturers are run-of-the-mill stuff, others are, or were, deadly, such as the ones below.

Gamboge

Think about a corruption of the name Cambodia, the country, and you will get gamboge, the colour. Think about Asian monks’ robes coloured with saffron or turmeric, and the brightest and purest yellow robe is dyed with gamboge. Gamboge comes from the latex of a tree, Garcinia hanbury, an evergreen tree that reaches up to 15 meters.  Gamboge can also be obtained from other types of garcinias that grow in different regions of Asia.

Collection of the dark brown latex is similar to the collection of latex from the rubber tree, or maple sap for syrup.  The garcinia trunk is slashed and the resin trickles into lengths of bamboo, where it solidifies.  In its more beneficial use, gamboge becomes alive when touched by an artist’s brush dipped in water.  It’s used in watercolours, oils, and simulates gold paint on scrolls and miniatures.

Painters such as Rembrandt, J.M.W. Turner, and Joshua Reynolds used gamboge in their palettes. The colour Hooker’s green was invented by William Hooker, the Royal Horticultural Society’s botanical artist, who mixed gamboge and Prussian blue. 

Gamboge powder or cake has other uses, too: it repels and kills insects, and it is a powerful laxative even in even small quantities. The workers from Winsor & Newton, the company that imported the pigment to the UK, used to rush to the bathroom several times a day when crushing raw gamboge cylinders. The company stopped using gamboge in 2005. 

In larger quantities, gamboge can kill, as happened to a Captain MacKenzie in 1836, who was advised by his medicine man to take 35 pills that contained gamboge.

From the beginning of the 20^th century, gamboge has been substituted by an artificial pigment called aureolin (or cobalt yellow).  Aureolin doesn’t like being mixed with oils, but is a stable friend of watercolours produced by the largest artists’ materials companies.

Orpiment

Also from the yellow spectrum, orpiment has had a varied and adventurous life, for it glitters and resembles gold. Orpiment, derived from the Latin word auripigmentum, is a product from hot-springs and hydrothermal veins. It is found in China, Russia, Iran, a few places in Europe and the United States.

Artists have used ground orpiment to decorate Tutankhamun’s tomb and the Taj Mahal;  to paint Egyptian papyruses and illuminated manuscripts. Countless alchemists, always in search of the next gold nugget, tried to turn orpiment into real gold, and Caligula, the Roman emperor, also had a try: all without success. This is a lonely and self-centred pigment:  it doesn’t like to work with other pigments, for everything painted on it turns black.

Orpiment has the potential to ruin not only paintings, but also people:  60% of its composition is arsenic, and its real name is arsenic sulphide.  Artists have been warned about its toxicity since the renaissance, but the attraction of gold, even if fake, seems too much to give it up.  However, in the old days people believed that a little orpiment went a long way to cure anaemia and ailments of the nervous system, and it was also used in Chinese medicine.

Orpiment has been phased out of artists’ materials, substituted by cadmium yellow.

Scheele’s Green

The Swedish scientist Carl W. Scheele fell in love with a bright green from a chemical compound he was studying, and he realised that the industry of pigments and dyes was terribly short on greens. Put the two together, and, pretty soon, lashings of the compound copper arsenite, where Scheele’s green comes from, were used in the production of upholstery and dress fabrics, carpets, wallpapers, artificial flowers, wall paints, wax candles, medicines, children’s toys, and confectionery. This was in 1775, and Scheele’s motto was, “What is a little arsenic when you’ve got a great new colour to sell?”

Other names for Scheele’s Green were Paris Green, Schloss Green, and Emerald Green.  J.M.W. Turner used it mixed with oil. Charles Dickens wanted to redecorate his house in Scheele’s green, but his wife was against it (Guess who won?).  William Morris used Scheele’s green on his wallpapers.

Doctors were apparently baffled by the number of people presenting the same symptoms: nausea, vomiting, diarrhoea, rashes, listlessness, pustules, heart disease, cancer, and ultimately death.  In 1880, the researcher Henry Carr presented some of his findings at the Society of Arts in London, stating that only “two to three grains” of arsenic would kill a man, and the production of arsenic in England was 4,809 tons a year. The British Medical Journal published a paper stating that a “six-inch square sample of wallpaper was found to contain enough arsenic to poison two adults.” A doctor at Guy’s Hospital in London discovered that a patient’s green curtains contained 60 grams of arsenic per square yard, something that prompted him to write to The Times questioning “the atmosphere of a ball room” when “dancing must be constantly discharging arsenic poison.”

Arsenic was Napoleon’s last Waterloo. After he died, Napoleon’s hair was tested for poisoning, and it was discovered that he had died of arsenic poisoning.  The wallpaper in Napoleon’s house in St. Helena was printed in Scheele’s green.

It took until 1895, when safety regulations were enacted in Britain, for Scheele’s green fever to abate. That was 120 years after the invention of Scheele’s green. Mercifully, people became aware of its dangers, and demanded arsenic-free products. But there are no estimates of what I imagine to be a huge number of people who died because they loved that green and wanted to bring more colour into their lives.   

So, beware: when something is natural, or looks like gold, or seems green, it may be none of those things and it may be bad for you. Or it may be all of those things and still be bad for you.

Besides the above links, I have also consulted the following:

Finley, V. (2002) Colour. Travels through the Paintbox. London: Hodder and Stoughton.

St.Clair, K. (2016) The Secret Lives of Colour.  London: John Murray Publishers.