Smoke, Soot and Poisoned Rivers

Industrial cities were notorious for pollution. Coal smoke darkened skies and buildings, and fogs in London and Manchester could last for days. Chemical works released acid gases: the Leblanc process for making soda emitted hydrochloric acid that damaged crops and trees. In 1863 Britain passed the Alkali Act, one of the first modern pollution-control laws, which required factories to capture most of these emissions and created an inspectorate led by chemist Robert Angus Smith.

Smith studied polluted rain, coined the term 'acid rain' in 1852, and set out his findings in the book Air and Rain in 1872. Rivers became open sewers for factories and towns, and the Rivers Pollution Prevention Act of 1876 tried, with limited success, to stop dumping. Even nature changed: dark forms of the peppered moth became common near industrial cities because they were camouflaged against soot-covered trees. Pollution was seen at the time as the price of prosperity, but reformers began to challenge that view.