The piazza outside St Paul's church, Covent Garden, London, full of people selling their wares: a man is holding a placard advertising the products of Doctor Rock, a medicine vendor, and is holding up a bottle of the medicine. Engraving by W. Hogarth, 1738.

A detail in 'The four times of the day: morning' engraved by William Hogarth in 1738 after his painting. Doctor Rock (Richard Rock 1690-1777) was a medicine vendor who frequented the London areas of Tower Hill, St. Paul's Cathedral and Covent Garden. He offered for sale his "anti-venereal, grand, specifick pill". He was represented in several caricatures: Hogarth referred to him in A harlot's progress pl. V, The march to Finchley, and in the present scene