friend:" "Having sat up late one evening, under considerable anxiety for
one of his children, who was ill, he fell asleep in his chair, and had a
frightful dream, in which the prominent figure was an immense baboon. He
awoke with the fright, got up instantly, and walked to a table which was
in the middle of the room. He was then quite awake, and quite conscious
of the articles around him; but close by the wall in the end of the
apartment he distinctly saw the baboon making the same grimaces which he
had seen in his dreams; and this spectre continued visible for about half
a minute." Now, a man who saw only a baboon would be quite ready to admit
that it was but an optical illusion; but if, instead of a baboon, he had
seen an intimate friend, and that friend, by some coincidence of time, had
died about that date, he would be a very strong-minded man if he admitted
for the mystery of seeing his friend the same natural solution which he
would readily admit for seeing a baboon.

[6] See Muller's observations on this phenomenon, "Physiology of the
Senses," Baley's translation, p. 1395.

[7] Sir David Brewster's Letters on Natural Magic, p. 39.

[8] Newton's explanation is as follows: "This story I tell you to
let you understand, that in the observation related by Mr. Boyle, the
man's fancy probably concurred with the impression made by the sun's
light to produce that phantasm of the sun which he constantly saw in
bright objects, and so your question about the cause of this phantasm
involves another about the power of the fancy, which I must confess is
too hard a knot for me to untie. To place this effect in a constant
motion is hard, because the sun ought then to appear perpetually. It
seems rather to consist in a disposition of the sensorium to move the
imagination strongly, and to be easily moved both by the imagination and