The long downswing in the price level that started in the 1870s and
continued until the mid 1890s was behind some of the main
contributions to monetary macroeconomics and to the quantity theory of
money made at the time by Marshall (1887), Fisher (1896) and Wicksell
(1898), among others. An excellent source on that is D. Laidler's
(1991) book "The Golden Age of the Quantity Theory".
Mauro Boianovsky