Several novels by Edmond and Jules de Goncourt (In 18..., Charles Demailly, Renée Mauperin, Manette Salomon) offer long and rich descriptions of the Seine. We examine them in order to tease out their shared poetics, while also revealing a few notable exceptions. The Goncourts readily interrupt the narrative thread of a novel to indulge in compositions brimming with nuances of color, plays of light and shadow, contrasting movements, and orchestrations of sound. Without being descriptions of real paintings, these passages are sometimes inspired by a particular painter or work, thereby drawing the reader’s attention to the authors’ literary attempts to rival artists whom they admire. The geographical settings of these scenes vary, but they share a mixed tone that combines gaiety and melancholy. The Seine and its banks often function in the Goncourts’ work as a deceptive or revealing locus amoenus where brief idyllic and romantic interludes unfold that nonetheless foreshadow imminent disaster. A melancholic tone also taints numerous references to the Seine in the Journal, especially in entries by Edmond after his brother’s death.