text: H.W. Janson discovered a portrait of a woman on the back of one version of this painting, which he identified as the artist's cousin Anna Landolt.
full_question: H.W. Janson discovered a portrait of a woman on the back of one version of this painting, which he identified as the artist's cousin Anna Landolt. This painting was popularized in England when an engraving of it was included in the text of Erasmus Darwin's The Botanical Garden, which has a frontispiece made by this work's artist. The most notable version of this painting features yellow drapery with gray lines, which were painted without regard to illusionistic depth. The Basel version of this painting features a statuette of a naked man and woman engaged in erotic activity on a dresser, while the Frankfurt version repositions the vials on a nightstand to be in front of a mirror. This painting, which provided the model for its artist's illustration of Paradise Lost titled The Shepherd's Dream, features an ethereal horse poking its head through some curtains, as well as an incubus on top of an erotically posed woman. For 10 points, name this Romantic masterpiece of Henry Fuseli.
first_sentence: H.W. Janson discovered a portrait of a woman on the back of one version of this painting, which he identified as the artist's cousin Anna Landolt.
raw_answer: The Nightmare