“Today’s Doodle shows Macintosh enjoying a Scottish rain shower whilst testing his ingenious invention,” Google says.
Here’s what you need to know about Macintosh:
1. He Was Born in Glasgow, Where His Father Was a Dye-Maker & Merchant Who Found a Way to Use People’s Urine for Profit
Macintosh attended school in England, before returning home to begin his career. He began working as a clerk in Glasgow for a local merchant at a young age, and was expected to follow in his father’s footsteps, but instead spent most of his spare time focusing on science, his true love.
His merchant father also had a background in science and manufacturing, as a dye maker.
“His father originally came from the Highlands, moving to Glasgow to set up a factory in Dennistoun in 1777 to manufacture a violet-red dying powder made from lichens (cudbear),” according to the University of Strathclyde’s Science on the Streets website.
Charles Macintosh would travel around Europe to find licehns, flowers and plants for potential colors and materials, and to meet with potential business partners for his father, Cynthia Barnett writes in Rain: A Natural and Cultural History.
Another ingredient in the dye made by Macintosh’s father was ammonia, which he acquired from an unusual source.
“For many years, Macintosh’s father had paid for pee,” Barnett writes. “The poor would save up the family’s urine and hand it over to landlords when it came time for pickup by George Macintosh’s collectors. The elder Macintosh used the ammonia to manufacture cudbear, a coveted red-purple dye made from licens.”
2. His Rainproof Cloth Helped British Explorers Survive an Expedition to the Arctic
Macintosh left his job as a clerk before he reached the age of 20 to focus on chemistry, according to Today in Science History.
He was self-taught and had a knack for the burgeoning scientific field, Cynthia Barnett writes in her book, Rain: A Natural and Cultural History:
He was supposed to learn mercantile affairs and help sell his father’s goods, but his mind was captivated by chemistry. The new scientific discipline was just coming into its own, out of the miasma and superstition of alchemy. Macintosh had an ether-clear native talent for mixing and morphing its elements. At eighteen, he was corresponding with the well-known chemists – most were then physicians – of Scotland and England, inquiring about chemistry lectures and how he might make colors from vegetables. He began traveling to Edinburgh to study with Joseph Black, a medical professor who had discovered ‘fixed air,’ soon called carbon dioxide. Black, with Macintosh and some other students, formed the earliest-known chemical society. Before Macintosh turned twenty he had written society papers on alcohol, alum, crystallization and the ‘application of the blue colouring matter of vegetable bodies. He was not yet twenty-one when he quit the county house to set up his own plant to manufacture sal ammoniac, a crystalline salt in high demand to make everything from tinned copper to pharmacy cures.
His plant, opened in 1797, was the first alum works, according to the Scotsman. His plant also produced ammonium chloride and Prussian blue dye. Macintosh, about that same time, introduced the manufacture of lead and aluminum acetates to Britain, and developed a new way to dye cloth, according to The Scotsman.
Barnett writes that Macintosh picked up his father’s methods of using waste products for profit. Like his father, he collected soot and urine, extracting salt from it in his plant.
Macintosh’s most famous invention came while experimenting with the waste products from coal-gas works.
“In the ethos of his father’s generation of dye makers who sourced ammonia from Glasgow’s human urine stream, Macintosh had a nothing-wasted mind-set. His discovery of the long-sought solvent for rubber came out of his search for uses of some of the nastiest by-products of the nineteenth century progress,” Barnett writes. “Gas lamps were becoming popular in the cities of Europe, lighting up the wealthier streets and private homes. But the tar sludge left behind in the manufacture of coal gas was a public menace … Macintosh saw practical uses in the sludge and wastewater, which include valuable ammonia. In 1819, Glasgow Gas Works was only too happy to sign a contract to sell him all the waste it produced.”
According to Today in Science, the sludge led to Macintosh’s famed invention:
He utilized the ammonia in the production of cudbear, a useful dye extracted from various lichens. By varying the choice of mordant used with this dye, manufacturers could colour textiles in a range of shades from pink to blue. The tar could be distilled to produced naphtha – a volatile, oily liquid hydrocarbon mixture. Although this could be used in flares, from 1819, Macintosh continued to experiment to find more ways to utilize naphtha, so that the original tar waste could yield more value.
The invention for which Macintosh is best known came when these investigations of naphtha yielded a process for waterproofing fabric. In June 1823, Macintosh patented his process using a solution of india-rubber in naphtha soaked between two layers of cloth forming a sandwich that was pressed together. The rubber interior provided a layer impermeable to water, though still flexible. His patent, No. 4,804, described how to “manufacture for rendering the texture of hemp, flax, wool, cotton, silk, and also leather, paper and other substances impervious to water and air.”
Macintosh’s invention was met with skepticism from tailors in Glasgow, but a deal with the Royal Navy helped prove its worth. According to On This Day in Scotland, the explorer John Franklin and his crew were outfitted with the material during their exploration of the Arctic in 1824.
The British army also ordered the rainproof fabric.
He soon opened a production plant in Manchester and the coats began to be sold to the public.
Macintosh was inducted into the famed Royal Society as a fellow in 1823.
3. The Mackintosh Raincoat Is Named for Him, Though It Is Spelled With a K
The Mackintosh raincoat, though spelled differently, is named for Macintosh. The iconic coats, which were first created with materials invented by Macintosh, are still handmade in Scotland, according to Scotland Now.
“Local tailors wanted nothing to do with the new material, so in 1840 he moved to Manchester, where his fabric was used to make raincoats that became known by his company’s name as the mackintosh. The additional letter ‘k’ is unexplained,” according to Scotland Now.