by a diorama.  Three lanterns would converge on the same screen.  The first throws an image of what the imagination will discard, the second of that which it will retain, the third of that which it will supply.  Turn on the first and second, and the picture on the screen will be identical with that which fell on the retina.  Shut off the first and turn on the third, and the picture will be identical with the illusion.

Turner the painter made frequent use of a practice analogous to that of looking for fire-faces in the burning coals; he was known to give colours to children to daub in play on paper, while he keenly watched for suggestive but accidental combinations.

I have myself had frequent experience of the automatic construction of fantastic figures, through a practice I have somewhat encouraged for the purpose, of allowing my hand to scribble at its own will, while I am giving my best attention to what is being said by others, as at small committees.  It is always a surprise to me to see the result whenever I turn my thoughts on what I have been subconsciously doing.  I can rarely recollect even a few of the steps by which the drawings were made; they grew piece-meal, with some almost forgotten notice, from time to time, of the sketch as a whole.  I can trace no likeness between what I draw and the images that present themselves to me in dreams, and I find that a very trifling accident, such as a chance dot on the paper, may have great influence on the general character of any one of these automatic sketches.

Visions, like dreams, are often mere patchworks built up of bits of recollections.  The following is one of these:—­

“When passing a shop in Tottenham Court Road, I went in to order a Dutch cheese, and the proprietor (a bullet-headed man whom I had never seen before) rolled a cheese on the marble slab of his counter, asking me if that one would do.  I answered ‘Yes,’ left the shop, and thought no more of the incident.  The following evening, on closing my eyes, I saw a head detached from the body rolling about slightly on a white surface.  I recognised the face, but could not remember where I had seen it, and it was only after thinking about it for some time that I identified it as that of the cheesemonger who had sold me the cheese on the previous day.  I may mention that I have often seen the man since, and that I found the vision I saw was exactly like him, although if I had been asked to describe the man before I saw the vision I should have been unable to do so.”

Recollections need not be combined like mosaic work; they may be blended, on the principle of composite portraiture.  I suspect that the phantasmagoria may be in some part due to blended memories; the number of possible combinations would be practically endless, and each combination would give a new face.  There would thus be no limit to the dies in the coinage of the brain.