e precisely
like these constituting the letters in the body of the note, which
were acknowledged to have been written by the alleged forger of the
note. Upon the introduction of this testimony the criminal withdrew
the plea of not guilty and implored the mercy of the court."

As one means of determining whether the whole of a writing was
executed at the same time, and with the same ink, or at different
times, and with different inks, Mr. Peacock further says that the
photographic process is very effective because it not only copies the
forms of letters but takes notice of differences in the color of two
inks which are inappreciable by the eye. He states that:

"Where there is the least particle of yellow present in a color, the
photograph will take notice of the fact by making the picture blacker,
just in proportion as the yellow predominates, so that a very light
yellow will take a deep black. So any shade of green, or blue, or red,
where there is an imperceptible amount of yellow, will pink by the
photographic process more or less black, while either a red or blue
varying to a purple, will show more or less paint as the case may be."

As to deception which the eye will not detect, in regard to the age of
paper, he says:

"I have repeatedly examined papers which have been made to appear old
by various methods, such as washing with coffee, with tobacco, and by
being carried in the pocket, near the person, by being smoked or
partially burned, and in various other ways. I have in my possession a
paper which has passed the ordeal of many examinations by experts and
others, which purports to be two hundred years old, and to have been
saved from the Boston fire. The handwriting is a perfect fac-simile of
that of Thomas Addington, the town clerk of Boston, two hundred years
ago, and yet the paper is not over two years old."

The most remarkable case of deception to the eye, even when aided by
magnifying glasses, is in determining when two pen strokes cross each
other, which stroke was made first. Mr. Peacock does not explain how
the deception is possible, but that it occurs as matter of fact, he
shows by an account of a very decisive experiment. Taking ten
different kinds of ink, most commonly on sale, he drew lines on a
piece of paper in such a way as to produce a hundred points of
crossing and so that a line drawn with each of ink passed both over
and under all the lines drawn with the other inks. He, of course,
knew,