The Consul is referring to Percy Bysshe Shelley's "Alastor; or The Spirit of Solitude" (1816), ll. 681-88.
Oh, that the dream
Of dark magician in his visioned cave,
Raking the cinders of a crucible
For life and power, even when his feeble hand
Shakes in its last decay, were the true law
Of this so lovely world! But thou art fled
Like some frail exhalation; which the dawn
Robes in its golden beams, – ah! thou hast fled.
The poem, Shelley's first important work, is based on the poet's contemplation of his own certain death. It shows the idealist, happy in his pursuit of beauty, but seeking in reality the counterpart of his dreams; meeting with frustration, he plunges into despair and dies; his final sentiments epitomised in the lines cited by the Consul. The motto of "Alastor" is striking: "I loved not yet – I loved to love – I sought something to live – for I loved to love."
"Another fellow with ideas ... The story I like about Shelley is the one where he just lets himself sink to the bottom of the sea – taking several books with him of course – and just stayed there, rather than admit he couldn't swim." – UTV, 207.
Above: Engraving of Amelia Curran's portrait of the poet. The original is in the National Portrait Gallery, London.