The phrase spoke of an "exhalation" from certain rivers, which "spread around like a hoar frost." Coleridge's version, a couplet in "The Rime of the Ancient Mariner," reads: "[The sun's] beams bemocked the sultry main / Like April hoar-frost spread." The echo is conjectural, but the repeated words "hoarfrost" and "spread" would seem to clinch the accuracy of Wolfe's discovery.