_The Colour of Ink in Writings._--My attention was called to this subject
some years ago by an attempt made in a judicial proceeding to prove that
part of a paper produced was written at a different time than the rest,
because part differed from the rest in the shade of the ink. The following
conclusions have been the result of my observations upon the subject:
1. That if the ink of part of a writing is of a different shade, though of
the same colour, from that of the other parts, we cannot infer from that
circumstance alone that the writing was done at different times. Ink taken
from the top of an inkstand will be lighter than that from the bottom,
where the dregs are; the deeper the pen is dipped into the ink, the darker
the writing will be.
2. Writing performed with a pen that has been used before, will be darker
than that with a new pen; for the dry residuum of the old ink that is
encrusted on the used pen will mix with the new ink, and make it darker.
And for the same reason--
3. Writing with a pen previously used will be darker at first than it is
after the old deposit, having been mixed up with the new ink, is used up.