_Somnambulism._--Bettinelli wrote: “Poetry may almost be called a dream which is accomplished in the presence of reason, which floats above it with open eyes.” This definition is the more exact since many poets have composed their poems in a dream or half-dream. Goethe often said that a certain cerebral irritation is necessary to the poet; many of his poems were, in fact, composed in a state bordering on somnambulism. Klopstock declared that he had received several inspirations for his poems in dreams. Voltaire conceived during sleep one of the books of his _Henriade_; Sardini, a theory on the flageolet; Seckendorf, his beautiful ode to imagination, which in its harmony reflects its origin. Newton and Cardan resolved mathematical problems in dreams. Nodier composed _Lydia_, together with a complete theory of future destiny, as the result of dreams which “succeeded each other,” he wrote, “with such redoubled energy, from night to night, that the idea transformed itself into a conviction.” Muratori, many years after he had ceased to write verse, improvised in a dream a Latin pentameter. It is said that La Fontaine composed in a dream his _Deux Pigeons_, and that Condillac completed during sleep a lesson interrupted in his waking hours.[55] Coleridge’s _Kubla Khan_ was composed, in ill health, during a profound sleep produced by an opiate; he was only able to recall fifty-four lines. Holde’s _Phantasie_ was composed under somewhat similar conditions. _Genius in Inspiration._--It is very true that nothing so much resembles a person attacked by madness as a man of genius when meditating and moulding his conceptions. _Aut insanit homo aut versus facit._ According to Réveillé-Parise, the man of genius exhibits a small contracted pulse, pale, cold skin, a hot, feverish head, brilliant, wild, injected eyes. After the moment of composition it often happens that the author himself no longer understands what he wrote a short time before. Marini, when writing his _Adone_, did not feel a serious burn of the foot. Tasso, during composition, was like a man possessed. Lagrange felt his pulse become irregular while he wrote. Alfieri’s sight was troubled. Some, in order to give themselves up to meditation, even put themselves artificially into a state of cerebral semi-congestion. Thus Schiller plunged his feet into ice. Pitt and Fox prepared their speeches after excessive indulgence in porter. Paisiello composed beneath a mountain of coverlets. Descartes buried his head in a sofa. Bonnet retired into a cold room with his head enveloped in hot cloths. Cujas worked lying prone on the carpet. It was said of Leibnitz that he “meditated horizontally,” such being the attitude necessary to enable him to give himself up to the labour of thought. Milton composed with his head leaning over his easy-chair.[56] Thomas and Rossini composed in their beds. Rousseau meditated with his head in the full glare of the sun.[57]