Query: In what century did gin houses proliferate throughout Britain?
Context: By the early 19th century, encouraged by lower duties on gin, the gin houses or "Gin Palaces" had spread from London to most cities and towns in Britain, with most of the new establishments illegal and unlicensed. These bawdy, loud and unruly drinking dens so often described by Charles Dickens in his Sketches by Boz (published 1835–1836) increasingly came to be held as unbridled cesspits of immorality or crime and the source of much ill-health and alcoholism among the working classes.