In the previous section to the one just quoted, Locke refers to the exaggeration of ideas which form so common a feature of our mental actions during sleep. “It is true,” he says, “we have sometimes instances of perception while we are asleep, and retain the memory of those thoughts; but how extravagant and incoherent for the most part they are, how little conformable to the perfection and order of a rational being, those acquainted with dreams need not be told.”

And yet many remarkable stories are related, which tend to show the high degree of activity possessed by the mind during sleep. Thus it is said of Tartini,[35] a celebrated musician of the eighteenth century, that one night he dreamed he had made a compact with the devil, and bound him to his service. In order to ascertain the musical abilities of his servitor, he gave him his violin, and commanded him to play a solo. The devil did so, and performed so admirably that Tartini awoke with the excitement produced, and seizing his violin, endeavored to repeat the enchanting air. Although he was unable to do this with entire success, his efforts were so far effectual that he composed one of the most admired of his pieces, which in recognition of its source he called the “devil’s sonata.”

Coleridge gives the following account of the composition of the fragment, Kubla Khan:

“In the summer of 1797, the author, then in ill health, had retired to a lonely farm-house, between Perlock and Linton, on the Exmoor confines of Somerset and Devonshire. In consequence of a slight indisposition, an anodyne had been prescribed, from the effects of which he fell asleep in his chair at the moment that he was reading the following sentence, or words of the same substance, in Purchas’s Pilgrimage: ‘Here the Khan Kubla commanded a palace to be built, and a stately garden thereunto. And thus ten miles of fertile ground were inclosed with a wall.’ The author continued for about three hours in a profound sleep, at least of the external senses, during which time he had the most vivid confidence that he could have composed not less than from two to three hundred lines, if that, indeed, can be called composition, in which all the images rose up before him as things with a parallel production of the corresponding expression without any sensation or consciousness of effort. On awaking, he appeared to himself to have a distinct recollection of the whole; and taking his pen, ink, and paper, instantly and eagerly wrote down the lines that are here preserved. At this moment he was unfortunately called out by a person on business from Perlock, and detained by him above an hour; and on his return to his room, found to his no small surprise and mortification, that though he still retained some vague and dim recollection of the general purport of the vision, yet with the exception of some eight or ten scattered lines and images, all the rest had passed away like the images on the surface of a stream into which a stone had been cast, but, alas! without the after restoration of the latter.”

Dr. Cromwell,[36] citing the above instance of poetic inspiration during sleep, states that, having like Coleridge taken an anodyne during a painful illness, he composed the following lines of poetry, which he wrote down within half an hour after awaking. These lines, though displaying considerable imagination, are not remarkable for any other quality.

“Lines composed in sleep on the night of January 9th, 1857.

“Scene.—Windsor Forest.

“At a vista’s end stood the queen one day
Relieved by a sky of the softest hue;
It happen’d that a wood-mist risen new,
Had made that white which should have been blue.
A sunbeam sought on her form to play;
It found a nook in the bowery nave,
Through which with its golden stem to lave
And kiss the leaves of the stately trees
That fluttered and rustled beneath the breeze;
But it touched not her, to whom ’twas given
To walk in a white light pure as heaven.”

In the last two of these instances it is impossible to say whether the individuals were really asleep or not, as the opium or other narcotic taken is a very disturbing factor in both conditions, and doubtless was the exciting cause of the activity in the imagination. No more graphic account of the effects of opium in arousing the imagination to its highest pitch has been written than that given by De Quincey.[37] He says:

“At night when I lay awake in bed, vast processions passed along in mournful pomp; friezes of never-ending stories, that to my feelings were as sad and solemn as if they were stories drawn from times before Œdipus or Priam, before Tyre, before Memphis. And at the same time a corresponding change took place in my dreams; a theater seemed suddenly opened and lighted up within my brain, which presented nightly spectacles of more than earthly splendor.” And then, after referring to the various scenes of architectural magnificence, and of beautiful women which his imagination conceived, and which forcibly recalls to our minds the poetical effusions of Coleridge and Cromwell, he gives the details of another dream, in which he heard music. “A music of preparation, of awakening suspense; a music like the opening of the Coronation Anthem, and which like that gave the feeling of a vast march, of infinite cavalcades filing off, and the tread of innumerable armies.”