looking in that glass, I saw myself reflected nearly at full length;
but my face, I noticed, had two separate and distinct images, the tip
of the nose of the one being about three inches from the tip of the
other. I was a little bothered, perhaps startled, and got up and looked
in the glass, but the illusion vanished. On lying down again, I saw it
a second time, plainer, if possible, than before; and then I noticed
that one of the faces was a little paler--say five shades--than the
other. I got up, and the thing melted away, and I went off, and, in the
excitement of the hour, forgot all about it,--nearly, but not quite,
for the thing would once in a while come up, and give me a little pang
as though something uncomfortable had happened. When I went home, I
told my wife about it, and a few days after I tried the experiment
again, when, sure enough, the thing came back again; but I never
succeeded in bringing the ghost back after that, though I once tried
very industriously to show it to my wife, who was worried about it
somewhat. She thought it was 'a sign' that I was to be elected to a
second term of office, and that the paleness of one of the faces was an
omen that I should not see life through the last term."

The incident is of no interest excepting in so far as everything about
Lincoln is of interest. The phenomenon is an optical illusion not
uncommon. One image--the "paler," or more indistinct, one--is reflected
from the surface of the glass, while the other is reflected from the
silvered back of the glass. Though Lincoln understood that it was an
optical illusion, yet the thought of it evidently weighed on him.
Otherwise he would not have repeated the experiment several times, nor
would he have told of it to different persons.