An orphan adopted by a miller, and beloved by Elvino, a rich farmer. The night before her espousals she is found in the bed of Count Rodolpho, and is renounced by her betrothed husband. The Count explains to the young farmer and his friends that Amina is innocent, and has wandered in her sleep. While he is still talking, the orphan is seen getting out of the window of the mill, and walking in her sleep along the edge of the roof under which the mill-wheel is rapidly revolving. She crosses a crazy bridge, and comes among the spectators. In a few minutes she awakes, flies to Elvino, and is claimed by him as his beloved and innocent bride. —Bellini's best opera, La Sonnambula.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
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