But my analysis will be incomplete, if I do not revert to a point that I had almost forgotten. These abstract moods have often been confounded with the visions of slumber, being adduced as proofs of the perfection of mind during sleep. You reminded me, Astrophel, of the brilliant parody composed by Mackenzie, of the versification of Voltaire and La Fontaine, of the solution of the difficult problem by Condorcet, of the discussion of abstruse points of policy by Cabanis. You might have added Condillac, who asserts that when he was composing the “_Cours d’Etudes_,” he often left a chapter unfinished, but had it all in his mind when he awoke. And Franklin assures us, that he often _dreamed_ of the issue of important events in which he was engaged, believing the vision to be the influence of inspired prophecy. Dr. Haycock, of Oxford, too, is said to have composed and preached sermons in his sleep, in despite even of buffetings. These are not dreams, but the reveries of philosophers and poets. The faculties of perception are suspended: one only object occupies the mind, and the impression on the memory is vivid and permanent. Of this reverie I do not recollect a more interesting illustration than the “_Dream_ of Tartini,” and its exquisite product, “La Sonata di Diavolo.” This admirable violinist and once esteemed composer, relates the following anecdote as the origin of his _chef-d’œuvre_, the “Devil’s Sonata.” “One night, it was in the year 1713, I dreamed that I had made over my soul to his satanic majesty. Every thing was done to my wink; the faithful menial anticipated my fondest wishes. Among other freaks, it came into my head to put the violin into his hands, for I was anxious to see whether he was capable of producing anything worth hearing upon it. Conceive my astonishment at his playing a sonata, with such dexterity and grace, as to surpass whatever the imagination can conceive. I was so much delighted, enraptured, and entranced by his performance, that I was unable to fetch another breath, and, in this state, I awoke. I jumped up and seized upon my instrument, in the hope of reproducing a portion, at least, of the unearthly harmonies I had heard in my dream. But all in vain: the music which I composed under the inspiration, I must admit the best I have ever written, and of right I have called it the ‘Devil’s Sonata;’ but the falling off between that piece and the sonata which had laid such fast hold of my imagination is so immense, that I would rather have broken my violin into a thousand fragments, and renounced music for good and all, than, had it been possible, have been robbed of the enjoyment which the remembrance afforded me.”