In this picture, titled The visit to the quack doctor by Hogarth, a young viscount (the son of the bankrupt Earl Squanderfield) is shown visiting a quack doctor. The black patch on the viscount's neck indicates that he has syphilis; he may have brought the young prostitute to the doctor because he believes he has infected her with the disease. The picture has been interpreted in various ways. The doctor is based on Dr Rock, a French doctor with premises at St Martin's Lane, Westminster, and the setting has a wealth of detail of the doctor's consulting room and the tools of his trade.Painting credit: William Hogarth