preserve. His own account of this curious incident is as follows:--

"In the summer of 1797 the author, then in ill health, had retired to a
lonely farmhouse between Porlock 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 enclosed by a
wall.' The Author continued for about three hours in a profound sleep,
at least of the external senses, during which time he has the most
vivid confidence that he could not have composed 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 expressions, without any sensation or
consciousness of effect. 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 Porlock, 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 has been cast,
but, alas! without the after restoration of the latter."

This poem, though written in 1797, remained, like _Christabel_, in
MS. till 1816. These were then published in a thin quarto volume, together