Poems written in common meter typically follow the same basic rhyme scheme: ABCB. Indeed, this tends to be the preferred rhyme scheme in much of Dickinson’s own poetry. In this poem, however, she has shaken things up a bit by deciding to use a different variation for each of the three quatrains. Whereas the first quatrain uses the expected ABCB scheme, the second quatrain rhymes ABAB, and the third rhymes ABBB. This shifting rhyme scheme is significant for the way it moves from a heterogeneous form to a more homogenous form. The first quatrain is heterogeneous in the way it includes two unrhymed lines in addition to its one rhyming pair. It’s also worth noting that the one rhyme in this quatrain is a slightly weak one consisting of a slant rhyme between “soul” and “all” (lines 2 and 4). By contrast, the second quatrain is a bit more homogenous in that it’s organized into two rhyming pairs, both of which form exact rhymes. The third quatrain is even more homogenous in that it includes an exact triple rhyme that links three of the four lines. This formal shift to stronger and more frequent rhymes mirrors the poem’s thematic emphasis on hope.