When, after the hurrying anapaests, the verse returns to the strict iambic measure in the last couplet, the effect is a hush, in harmony with the meaning of the words.[21]

“Christabel” is not so unique and perfect a thing as “The Ancient Mariner,” but it has the same haunting charm, and displays the same subtle art in the use of the supernatural.  Coleridge protested that it “pretended to be nothing more than a common fairy tale.” [22] But Lowell asserts that it is “tantalising in the suggestion of deeper meanings than were ever there.”  There is, in truth, a hint of allegory, like that which baffles and fascinates in Christina Rossetti’s “Goblin Market”; a hint so elusive that the comparison often made between Geraldine and Spenser’s Duessa, is distressing to a reader of sensitive nerves.  That mystery which is a favourite weapon in the romanticist armoury is used again here with consummate skill.  What was it that Christabel saw on the lady’s bosom?  We are left to conjecture.  It was “a sight to dream of, not to tell,” [23] and the poet keeps his secret.  Lamb, whose taste was very fine in these matters, advised Coleridge never to finish the poem.  Brandl thinks that the idea was taken from the curtained picture in the “Mysteries of Udolpho”; and he also considers that the general situation—­the castle, the forest, the old father and his young daughter, and the strange lady—­are borrowed from Mrs. Radcliffe’s “Romance of the Forest”; and that Buerger’s “Lenore,” Lewis’ “Alonzo,” and some of the Percy ballads contributed a detail here and there.  But Quellenforschungen of this kind are very unimportant.  It is more important to note the superior art with which the poet excites curiosity and suspends—­not simply, like Mrs. Radcliffe, postpones—­the gratification of it to the end, and beyond the end, of the poem.  Was Geraldine really a witch, or did she only seem so to Christabel?  The angry moan of the mastiff bitch and the tongue of flame that shot up as the lady passed—­were they omens, or accidents which popular superstition interprets into omens?  Was the malignant influence which Geraldine exerted over the maiden supernatural possession, or the fascination of terror and repugnance?  Did she really utter the words of a charm, or did her sweet bedfellow dream them?  And once more, what was that upon her breast—­“that bosom old—­that bosom cold”?  Was it a wound, or the mark of a serpent, or some foul and hideous disfigurement—­or was it only the shadows cast by the swinging lamp?

That isolation and remoteness, that preparation of the reader’s mind for the reception of incredible things, which Coleridge secured in “The Ancient Mariner” by cutting off his hero from all human life amid the solitude of the tropic sea, he here secured—­in a less degree, to be sure—­by the lonely midnight in Sir Leoline’s castle.  Geraldine and her victim are the only beings awake except the hooting owls.  There is dim moonlight in the wood, dim firelight in the hall, and in Christabel’s chamber “the silver lamp burns dead and dim.”