"The Long Chain" traces the invention of the fluyt freighter in Holland in the 16th century. Voyages were insured by Edward Lloyd (Lloyd's of London) if the ships' hulls were covered in pitch and tar (which came from the colonies until the American War of Independence in 1776). In Culross, Scotland, Archibald Cochrane (9th Earl of Dundonald) tried to distill coal vapour to get coal tar for ships' hulls, which led to the discovery of ammonia. The search for artificial quinine to treat malaria led to the development of artificial dyes, which Germany used to produce fertilizers to grow wheat and led to the advancement of chemistry which in turn led to DuPont's discovery of polymers such as nylon.