Noble's essay examines Walt Whitman's investment in an often radical materialization of subjectivity, which both underlies his earliest claims to reinvent embodied experience and brings his poetic project to crisis. In the 1855 Leaves, Whitman's enthusiasm for the popular science of his era leads to the adoption of a progressive atomism that relocates the spiritual power of subjectivity within the material. “Song of Myself” thus develops a chemistry of embodied presence that makes it possible to demonstrate that “every atom belonging to me as good belongs to you.” In 1856, “Crossing Brooklyn Ferry” extends the reach of Whitman's materialist poetics by supplementing the perceptual mechanics of Lucretian physics (in which the sentient body is composed of and sustained by the flow of objects toward it) in order to produce a material subject capable, however ironically, of transcending material limitations. Many of Whitman's 1860 poems, however, also encounter a deathliness of matter (the speaker figured as a “trail of drift and debris,” for instance, in “As I Ebb'd with the Ocean of Life”). In his “Calamus” cluster especially, Whitman speaks as though from the margins of his own oeuvre, laboring to fashion a temporary space from which poems of democratic adhesion might be uttered. If in 1856 the atom enables the poet to transcend space and time, in 1860 he may convert matter into spirit, but he may not outlive it. Read in this light, Whitman's early editions of Leaves record an important ambivalence about the plenitudes secured by materialist thinking.