Born 250 years ago in Glasgow, Scotland, Charles Macintosh (1766-1843) is best known for inventing waterproof fabric. Initially woring as a clerk, he decided, at the age of 20, to devote his time entirely on chemical experiments.
He started working with byproducts of coal and tar, and found that the application of naphtha to rubber turned the rubber into a soluble paste, and could be applied to the surface of items to repel water. However, the rubber gum tended to become sticky and decompose when exposed to heat or cold.
Additional finetuning led to the use of vulcanized rubber, which was much more durable and resistant to varying temperatures. Vulcanized rubber was mainly developed by Charles Goodyear (both Charles coincidentally share a birthday!), and eventually used for waterproofing.
Macintosh also experimented with color dyes and bleaches, and processes to improve the manufacturing of iron.