On December 29, 1766, Charles Mackintosh was born in Glasgow, Scotland. Mackintosh, a clerk turned chemist, experimented with a byproduct of tar called naptha. One such experiment, involving cementing two thicknesses of India rubber together with use of the naptha (which made the rubber soluble), led to the invention of waterproof fabric. He was granted a patent for waterproof cloth in 1823, and in 1824 the first waterproof raincoat was sold that used his invention and was named after him. The Mackintosh, a rubberized raincoat also known as a Mack, is now the classic rainy-weather wear and has saved many persons from cold and unpleasant wetness.