Abstract: In Les Français peints par eux-mêmes, Janin wrote the general introduction, but also the monographs dedicated to the boys and girls of Paris, which offer a first entry into the urban poetics of Janin under the July Monarchy. But this represents just a small fraction of his work, which is full of stories, tales, prefaces, and novellas that traverse a poetics of the Parisian streets. It borrows from an imaginary of images, in other words, an economy of observation and representation.