Tar is modified resin produced primarily from the wood and roots of pine by destructive distillation under pyrolysis. It is a viscous black liquid. Production and trade in tar was a major contributor in the economies of Northern Europe and Colonial America. Its main use was in preserving and protecting wooden vessels against rot. The largest user was the Royal Navy. Demand for tar declined with the advent of iron and steel ships. Tar-like products can also be produced from other forms of organic… (More on Tar)