Final answer:
Emily Dickinson employs the sound devices of alliteration, assonance, and slant rhyme in her poem.
Step-by-step explanation:
Emily Dickinson employs the sound devices of alliteration, assonance, and slant rhyme in the phrase, "too cool for corn-" as well as in the line, "But when a boy and barefoot." Alliteration is the repetition of consonant sounds at the beginning of words (e.g., "cool" and "corn-"). Assonance is the repetition of vowel sounds within words (e.g., "cool" and "too"). Slant rhyme is the near rhyme or imperfect rhyme between two words (e.g., "boy" and "barefoot").
Learn more about Sound devices in poetry