The decision as to whether they have been made legitimately and before
a paper was executed, or subsequently to its execution, and with
fraudulent intent, must be arrived at by a comparison of the
handwriting in which the words appear, the ink with which they were
written, and the local features of each special case which usually are
not wanting.

To determine whether or not papers contain erasures the suspected
document should be examined by reflected and transmitted light.
Examine the surface for rough spots. Forgers after erasures frequently
endeavor to hide the scratched and roughened surface by applying a
sizing of alum, sandarach powder, etc., rubbing it to restore the
finish to the paper.

Distilled water applied to the suspected document at the particular
points under examination will dissolve the sizing applied by the
forger. If held to the light the thinning will show. The water may be
applied with a small brush or a medicine dropper. Water slightly
warmed may be used with good results at times.

Alcohol, if applied as described for water, will act more promptly and
show the scratched places. It may be well to use water first and then
alcohol.

To discover whether or not acids were used to erase, if moistened
litmus-paper be applied to the writing, the litmus-paper will become
slightly red if there is any acid remaining on the suspected document.
If the suspected spots be treated with distilled water, or alcohol, as
already described, the doctored place will show, when examined in