Charles Macintosh was born in Glasgow, Scotland, in 1766. Although he was supposed to become a merchant, like his father, the young Macintosh had a passion for chemistry and science. By the time he was twenty, he had opened a plant in Glasgow for producing ammonia from coal-gas waste. About the same time, he introduced the manufacture of lead and aluminum acetates to Britain. He also made advances in cloth-dyeing processes, opened Scotland's first alum works, helped devise a method for making bleaching powder, and developed improved methods of iron production. Macintosh is best known, however, for the water proof garment that bears his name.

A waste product of the Glasgow gasworks was naphtha, a volatile liquid hydrocarbon mixture. In 1819 Macintosh began experimenting with the naphtha and discovered that it dissolved rubber. Applying the knowledge of textiles he had gained as a dye-maker, Macintosh had the idea of using the liquid rubber to waterproof fabrics. He painted one side of wool cloth with the rubber solution, then laid a second thickness of cloth over it. The rubber interior made the resulting sandwich of cloth waterproof.

Macintosh patented his invention in 1823. Within a year, the chemist had a flourishing factory in Manchester, England, producing rainproof cloth for the British military, the Franklin Arctic expedition, and the general public. Thomas Hancock joined Macintosh and his other partners around 1829. Charles Macintosh & Company became famous for its "Macintosh Coat," the world's first raincoat, later known popularly as the mackintosh. (Where the k came from is a mystery.)

Macintosh was honored for his contributions to chemistry by his election in 1823 as a fellow of the Royal Society. He died at Dunchattan, near Glasgow, in 1843.