Cosmos Editorial
We are taking a look back at stories from Cosmos Magazine in print. This article appeared in June 2020.
Rage, power, danger, love… how fitting that red’s fiery, blood-soaked mark on the world was born in ochre, dangerous minerals and the crushed carcasses of countless bugs.
The first time humans used pigments to make communicative marks, they used the colour red –ochre. As a mineral, ochre doesn’t decay or wash away, which gives it a powerful longevity. This, says April Nowell, a paleolithic archaeologist from Canada’s University of Victoria, makes it “an ideal crayon or paint base”.
The earliest evidence of humans using ochre dates to Homo erectus, 285,000 years ago, while the earliest known drawings by Homo sapiens – a kind of cross hatch – were made by crafted and portable ochre crayons in Blombos Cave, 300 kilometres east of Cape Town, South Africa. The advent of this drawing implement, says Christopher Henshilwood from Norway’s University of Bergen, means “you can put a crayon into a bag, walk over the landscape and mark a rock or tree without needing to make paint or engrave something.” And this makes it easier to communicate.
Ochre was widely traded in indigenous Australia, moving out from major mining sites including Yarrakina in the Flinders Ranges, Wilgie Mia northeast of Geraldton, and Mt Roland in Tasmania, where George A Robinson wrote of watching women mine the ochre and pack portions into small kangaroo-skin bags. Pigment from the Yarrakina mine was transported more than 1000 kilometres north, beyond Alice Springs, in 25 kilogram blocks, while ochre from the open-cut pits of Wilgie Mia was traded as far away as the Nullarbor, the Kimberley and Cape York. White and yellow ochres were used for decoration, and Wilgie Mia boasts seams of green ochre as well. But red was the most powerful, the most prized and the most sought-after of the pigments – the lustrous sheen in some deposits, which makes it “glow in the dark”, is caused by the presence of other elements including free mercury (cinnabar) or mica.
At 700 nanometres, red has the longest wavelength of all visible light. It gives way to the just-invisibility of infrared, discovered by William Herschel at the end of the 18th century when he took the temperatures of the different colours along the spectrum and registered the temperature of the nocolour beyond red.
Red has a rich and complicated currency. It’s a colour associated with diverse moments and emotions, from the red heart of Valentine’s Day love and emoji affection to danger, wrath and control – a portrait of Princess Elizabeth, before being crowned as Elizabeth I, shows her in a red dress and coif to send an “unequivocal message of… political and moral strength”. From 1645, England’s New Model Army, dressed its infantrymen in Venetian red, giving the British military an obvious and distinctive power.
When the First Fleet set sail from Portsmouth in the spring of 1787, it carried a colonising cargo of convicts, red-coated marines and sundry others, a strange assemblage of items (including 100 pairs of scissors, a dozen tin saucepans, a printing press and a piano) and a shopping list of supplies to lay in on its way via Rio de Janeiro and Cape Town to Botany Bay. Among the various industries the British hoped might succeed in their new colonial outpost was the manufacturing of a supreme red dye – one that could go up against a long-held Spanish monopoly on the “brightest, strongest red”, as Amy Butler Greenfield writes in The Perfect Red, that the conquistadores appropriated from the Aztecs. It was the carmine red derived from cochineal.
Cochineal had become Spain’s second most profitable export from the New World after silver and was so desired in the European north that the Spanish monarchy demanded tribute of the stuff (6300 pounds per annum by the early 1500s – or 2.8 tonnes), and its price was included on the Amsterdam Commodity Exchange. It was the world’s most expensive dye between the 16th and 18th centuries.
A Spanish ship that sank in 1541 was recorded as carrying a “full load” of the dye, which was equal to 20,000 pounds (just over nine tonnes); imagine the colour of that ocean.
For more than three centuries, the Spanish had insisted that the colour was derived from a plant or a grain – to obscure and secure the true source of this bounty. In 1704, Antonie van Leeuwenhoek – a Dutch businessman and scientist now regarded as the father of microbiology – placed a cochineal particle under the lens of a newly invented microscope and saw six legs, a head and two wings. He was looking not at plant, but at animal; it was a bug. But this diagnosis was only confirmed in 1777 when the French naturalist Nicolas-Joseph Thiéry de Menonville stole into the cochineal source-state of Oaxaca “secretly on foot”, and managed to secure a supply of cactus pads and their insects.
Captain Arthur Phillip reached the port of Rio de Janeiro 10 years later with his shopping list of “all such seeds and plants… as were thought likely to flourish on the coast of New South Wales, particularly coffee, indigo, cotton, and the cochineal fig”.
He secured samples of Opuntia monacantha (a species of prickly pear) infested with the insects, and took them onboard to settle them in the new colony of NSW with hopes of great industry.
The source of this colour is indeed a small-scale insect, the cochineal bug, designated as Coccus cacti in 1758 by Linnaeus, and reclassified as Dactylopius coccus by the Italian zoologist Oronzo Gabriele Costa in 1835. The bug is a parasite that feeds on cacti and generates a bright red carminic acid to ward off predators.
Harvesting the bugs is a delicate business; each one has to be picked, brushed or knocked from a cactus pad into a small bag. The carminic acid – which accounts for around 20% of its bodyweight – is extracted and treated, either by immersion in hot water, exposure to sunlight, exposure to steam, or exposure to a hot oven to create carmine. Each method generates a different shade of red – as does the process of obtaining cochineal dye, which requires the raw and dried bodies of the insects to be pulverised. One pound of the colour can be sourced from 25,000 live insects… or 70,000 dried ones.
A 20 Colouring things red can be perilous. From the 10th century BCE, a powerful red called cinnabar was sourced from mercuric sulfide (cinnabar is the mineral; vermillion is the scarlet pigment it produces). This was used in everything from sculptures and jewellery to scrolls and frescoes, but had two main disadvantages: it tended to turn black when exposed to light, and it was poisonous.
A 2013 review of the toxicology of artificial food dyes published in the International Journal of Occupational and Environmental Health described synthetic (or aniline) dyes, as “complex organic chemicals… originally derived from coal tar, but… now made from petroleum”. Noting “the inadequacy of much of the testing” and “the fact that dyes do not improve the safety or nutritional quality of foods”, the authors suggested that “all of the currently used dyes should be removed from the food supply and replaced, if at all, by safer colourings”. As of 2017, two red dyes – Red No. 3 (Erythrosine) and Red No. 40 (Allura Red) – have approval from both the European Food Safety Administration and the US Food and Drug Administration. In 2019, the FAO’s global Codex Alimentarius allowed for Red No. 40 to be included, in varying levels, in more than 50 foods – ranging from candy and cake decorations to canned or bottled vegetables and seaweeds and frozen fish.
Amidst the complications and shortfalls of bright modern synthetic reds, ochre and cochineal remain. In Western Australia, the Wilgie Mia mine is still in operation, and ochre harvested there is still in trade, continuing at least 50,000 years of the pigment’s use across this continent – from burial ceremonies that date back 30,000 years at Lake Mungo in far western NSW, to evidence found in the 49,000-year-old Adnyamathanha rock shelters at Warratyi in the Flinders Ranges. And the cochineal bug has found a place in Australia’s landscape too. Phillip’s plants – and plans – failed to thrive. The prickly pear he carried from Rio de Janeiro was not the same species that later ravaged the Australian landscape: that scourge, Opuntia stricta, was introduced and widely distributed in the 19th century as a potential stock food, spreading voraciously until the introduction of cactoblastis caterpillars, Cactoblastis cactorum, which remains one of the most successful stories of biological control.
More recently, cochineal bugs proved successful as a biological control for another cactus, Opuntia robusta, across 14 farms in South Australia. The continent may host a cochineal industry yet.