James Thomson’s The Seasons is arguably a poem about seeing—its practices, theories, and connotations. Much lauded for its visual qualities, The Seasons reflects a unique adaptation of the natural philosophical discourse of putrefaction. Thomson’s cautiously optimistic view of experimental philosophy is evident in portions of The Seasons devoted to optical technology, such as the microscope and the prism. In addition to this focus on the material practices of experiment, Thomson investigates the intellectual and imaginative visual possibilities afforded by the putrefaction that haunts the landscape of Summer. The putrefying body is at once decaying and a remnant of its former self. Putrefaction is most vividly apprehended by experimenters through the olfactory sense—rotting things stink—but Thomson converts putrefaction into an exclusively visual metaphor. Putrefaction offers Thomson the language and framework to visualize the landscape and its fraught relationship to commercial and political interests. The discourse of putrefaction as an optical technology in Summer opens up the space to register the losses and costs of Britannia’s “progress.”