<p> The implication of the title of this thesis, Emily Dickinson's Spectrum, is that this poet had a highly individual attitude towards colour, an attitude which the analysis of colour-imagery in the poet's writings will illuminate. The first chapter of the thesis demonstrates how the poet's scientific background enabled her to set up a spectrum that differed from the "received" Newtonian spectrum in many ways. The second chapter shows how Dickinson's originality, a quality often noticed by critics, is to a large extent the product of her ability to manipulate the colours of her spectrum in a manner analogous to the practice of the pictorial artist. The third chapter explains, however, that though her use of colour was indeed original, her practice reflects the international anti-Newtonian "colour-revolution" of the era in which she lived, a revolution in which she had a significant role to play notwithstanding her apparent seclusion in Amherst. In the final chapter, Emily Dickinson's spectrum is set out, and each of its chief colours is shown to be a concise means of referring to a different complex or node of emotions that are at once personal and universal in their import.</p> / Thesis / Doctor of Philosophy (PhD)