If one chooses at hazard a Spenserian stanza out of Shelley and compares it with any stanza by Spenser, one sees the change, though it would be still more clear if one had chosen a lyrical passage. I will take a stanza out of Laon and Cythna, for that is story-telling and runs nearer to Spenser than the meditative Adonais:
‘The meteor to its far morass returned:
The beating of our veins one interval
Made still; and then I felt the blood that burned
Within her frame, mingle with mine, and fall
Around my heart like fire; and over all
A mist was spread, the sickness of a deep
And speechless swoon of joy, as might befall
Two disunited spirits when they leap
In union from this earth’s obscure and fading sleep.’