In this work on the industrial causes of pollution Smith coined the term acid rain. 

"The corrosive effect of polluted, acidic city air on limestone and marble was noted in the 17th century by John Evelyn, who remarked upon the poor condition of the Arundel marbles.^[2] Since the Industrial Revolution, emissions of sulfur dioxide and nitrogen oxides into the atmosphere have increased.^[3][4] In 1852, Robert Angus Smith was the first to show the relationship between acid rain and atmospheric pollution in Manchester, England.^[5]

"Though acidic rain was discovered in 1853, it was not until the late 1960s that scientists began widely observing and studying the phenomenon.^[6] The term "acid rain" was coined in 1872 by Robert Angus Smith.^{[7]"  (Wikipedia).} 

Digital facsimile from Google Books at this link.