personal relations with the party.

Comparison of handwriting, technically called _presumptio ex scripto
nunv viso_, is where a paper or papers are proved or admitted to be in
a party's handwriting, and a witness entirely unacquainted with the
party's handwriting, or the jury, is allowed to make a comparison by
juxtaposition of the writing so proved or admitted, and the writing
disputed.

All evidence of handwriting, except where the witness sees the
documents written, is in its nature comparison. It is the belief which
a witness entertains upon comparing the writing in question with an
exemplar in his mind derived from some previous writing.

In all the states of the Union the laws are uniform on the proposition
that experts may testify as to comparisons made and the results based
on such comparisons, except that the paper admitted to be genuine
shall not contain matter of a frivolous nature, etc.

In a broad, general way the element of common sense is the basework of
an expert's success in the business. He cannot depend upon anything
suggesting intuition. Where two signatures or two specimens of writing
are in question and one exhibit is a forgery and the other is genuine,
or where both are genuine, yet in question, the expert is in the
position of making his proofs and demonstrations convincing to the
layman--the hard headed citizen who insists that "you show me."
Frequently this citizen is on a jury where he has had to admit that he
is not particularly intelligent before he would be accepted for the
place.