Page:Popular Science Monthly Volume 19.djvu/545

Rh composite portraits admitted of being made photographically from a large number of components. I suspect that the phantasmagoria may be 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.

I have tried a modification of this process with but small success, which will at least illustrate a cause of the tendency in many cases to visualize grotesque forms. My object was to efface from a portrait that which was common among persons of the same race, and therefore too familiar to attract attention, and to leave whatever was peculiar in it. I proceeded on the following principle: We all know that the photographic negative is the converse (or nearly so) of the photographic positive, the one showing whites where the other shows blacks, and vice versa. Hence the superposition of a negative upon a positive transparency of the same portrait tends to create a uniform smudge. By superposing a negative transparency of a composite portrait on a positive of any one of the individual faces from which it was composed, all that is common to the group ought to be smudged out, and all that is personal and peculiar to that face ought to remain.

I have found that the peculiarities of visualization, such as the tendency to see Number-forms, and the still rarer tendency to associate color with sound, is strongly hereditary, and I should infer, what facts seem to confirm, that the tendency to be a seer of visions is equally so. Under these circumstances we should expect that it would be unequally developed in different races, and that a large natural gift of the visionary faculty might become characteristic not only of certain families, as among the second-sight seers of Scotland, but of certain races, as that of the gypsies.

It happens that the mere acts of fasting, of want of sleep, and of solitary musing, are severally conducive to visions. I have myself been told of cases in which persons accidentally long deprived of food became subject to them. One was of a pleasure-party driven out to sea, and not being able to reach the coast till nightfall, at a place where they got shelter but nothing to eat. They were mentally at ease and conscious of safety, but they were all troubled with visions, half dreams and half hallucinations. The cases of visions following protracted wakefulness are well known, and I also have collected a few. As regards the effect of solitariness, it may be sufficient to allude to the recognized advantages of social amusements in the treatment of the insane. It follows that the spiritual discipline undergone for purposes of self-control and self-mortification has also the incidental effect of producing visions. It is to be expected that these should often bear a close relation to the prevalent subjects of thought, and,